Cross-Reference to Related Applicationfs) This application claims priority in U.S. Provisional Patent Application No. 60/605,185, which was filed August 27, 2004, and U.S. Patent Application Serial No. 10/835,327, which was filed on April 28, 2004, and which are incorporated by reference herein. Technical Field This invention pertains to clips and arrays of clips for closing the necks of flexible bags. More particularly, the present invention relates to clips and strips of clips capable of being formed from flat material which can be separated by severing a connection between adjacent clips in a strip, including substantially flat material that is not necessarily brittle or frangible and can also be constructed from biodegradable materials. Background Art It is previously known to form adjacent clips in a strip so that adjacent clips are attached together by way of narrow, frangible webs of relatively brittle material. Pursuant to U.S. Patents No. 3,164,249; 3,164,250; 4,333,566; and 4,911,293, the clips are formed in strips that include such narrow, frangible webs of relatively brittle material. An individual clip is then either manually or machine manipulated so as to rotate and fracture a single clip from an adjacent clip in a strip, thereby breaking the webs of frangible material and separating an individual clip. However, such constructions are only suitable when clips are made from a relatively brittle, frangible material. Such clip construction is not suitable for use with relatively pliant and forgiving materials. Furthermore, the severing of individual clips in such manner can involve the production of stray chips of plastic or frangible material. These stray clips can be released by a random fracturing process which can contaminate food or other products within a bag, or can also cause malfunctioning of a clip-attaching mechanism. Furthermore, if the webs break in a relatively random manner and not in an intended manner, the webs can remain as sharp projections that protrude from the edge of a clip which can scratch or snag other products, or can scratch or snag the hands of a user or purchaser of the bag. U.S. Patent No. 4,215,606 discloses an alternative construction that minimizes the length of breaking portions between individual clips in a strip. By making the breaking portions of a negligible longitudinal length, an effort is made to avoid the production of undesirable chips of frangible material or snagging projections which can produce the above undesirable results. However, such construction involves a relatively complicated technique using a punch and die anvil of shear tools in order to produce the appropriate clip configuration. Furthermore, the strip of clips is still constructed of a frangible material. Accordingly, such construction cannot appear to provide a construction suitable for use with non-frangible materials, such as biodegradable materials or flexible materials suitable for reuse. By way of example, U.S. Patent No. 4,911,293 discloses a prior art strip 10 of clips 12, such as clips 12a-12d, which are formed together and which are subsequently severed from one another by bending and fracturing a frangible web connection either by hand or by using a mechanical apparatus, such as one of the machines utilized in U.S. Patent Nos. 3,163,969 and 3,163,972. As shown in Figure 1 , each clip, such as clip 12a, is provided with an aperture 14 that is accessed by a bag receiving passage 16 to receive a bunched-up open mouth portion of a bag where it is retained therein so as to close the bag. A pair of front surfaces 18 and 20 cooperate to form recessed portions that provide bag receiving passage 16. More particularly, a pair of tapered, converging fingers 28 and 30 cooperate to provide bag receiving passage 16. Clips, such as 12a-12d, in strip 10 are held together with adjacent clips via pairs of internesting protrusions 22 and 24 which are provided on opposite lateral edges of each respective clip 12. As disclosed within U.S. Patent No. 4,911,293, adjacent protrusions 22 and 24 are actually integrally formed together by way of a relatively small segment of interconnecting material that is not visible in Figure 1. Physical manipulation of a single clip, such as clip 12, relative to a remaining portion of strip 10 causes severing of such segments between protrusions 22 and 24 so as to sever an individual clip 12, either manually or by way of a machine. Additionally, pairs of projections 32 and 34 are provided within each aperture 14 to further ensure gripping of a bunched together mouth portion of a bag within aperture 14 when a bag is held in such aperture. The above-described techniques of bending and fracturing one or more frangible web connections will not work well on closure clips that are constructed of non-frangible materials, such as biodegradable materials and flexible or resilient materials. Accordingly, improvements are needed in light of the above-described deficiencies of the prior art presented herein. Summary A strip of bag clips are provided having individual clips each with a bag neck access opening joining a bag neck confining aperture within the clip. The bag neck access opening extends in a transverse direction relative to the length of the strip. Adjacent clips are joined together on adjacent sides via a central or medial and contiguously formed bridge portion defined by laterally formed slots. In one case, the clips are formed from a frangible material. In another case, the clips are formed from a flexible or resilient material. In a further case, the clips are formed from a biodegradable material. According to one aspect, a closure clip unit is provided with a plurality of closure clips integrally formed in a strip of essentially flat material. Each closure clip has an aperture provided in the clip with an entrance to the aperture provided at a lateral edge of the strip, and a central tab integrally provided between each successive clip of the strip and a respective next adjacent one of the clips. According to another aspect, a strip of closure clips is provided having a plurality of closure clips integrally formed in a strip of biodegradable material. According to yet another aspect, a bag closure clip is provided with a closure body of thin, flexible biodegradable sheet material with a bag confining mouth and a narrow opening located in a longitudinal side edge and a contiguous web in a lateral side edge configured to be integrally formed with another closure clip in the form of a multi-closure strip. Brief Description of the Drawings Preferred embodiments of the invention are described below with reference to the following accompanying drawings. Fig. 1 is a side elevational view of a strip of clips according to a prior art construction; Fig. 2 is a perspective view of a roll of an elongated strip of clips according to one construction of the present invention; Fig. 3 is an enlarged, plan view of a strip of clips according to the present invention; Fig. 4 is a sectional view taken along lines 4-4 of Fig. 3. Detailed Description of the Preferred Embodiments Reference will now be made to a preferred embodiment of Applicant's invention comprising a clip and a strip of clips for closing flexible bags. While the invention is described by way of a preferred embodiment, it is understood that the description is not intended to limit the invention to such embodiment, but is intended to cover alternatives, equivalents, and modifications which may be broader than the embodiment, but which are included within the scope of the appended claims. In an effort to prevent obscuring the invention at hand, only details germane to implementing the invention will be described in great detail, with presently understood peripheral details being incorporated by reference, as needed, as being presently understood in the art. Figure 2 illustrates a strip 110 of individual clips 112 according to one aspect of the present invention. Clips 112 are often referred to as closure clips. Each clip 112 has a central aperture 114 that communicates with a bag receiving passage, or a slit 116 that is provided in each clip 112 so as to extend in a lateral direction relative to strip 110. According to one construction, strip 110 is formed from a relatively flexible material such as polypropylene. An alternative resilient or flexible material comprises a high impact polyethylene. Further alternatively, strip 110 of clips 112 can be formed from a biodegradable material such as paper, wax-impregnated paper, any of a number of wood fiber based products, biodegradable plastics, or other natural or biodegradable materials that break down when exposed to elements within the environment. Even further alternatively, strip 110 of clips 112 can be formed from a relatively brittle, frangible material, as previously utilized within the prior art techniques presently known within the field. Further alternatively, strip 110 can be formed from wood or metal, such as steel, aluminum, or copper. For the case where strip 110 is formed from a ductile material such as copper, one benefit of the present invention can clearly be discerned because copper is not frangible under tactile manipulation. More particularly, prior art techniques for severing individual clips from a strip will not work with a ductile material such as copper. However, the use of the strips and clips described herein can be implemented even with ductile materials when the clips are cut or severed from a strip by way of an automatic clip-applying machine. Prior art techniques utilize an automatic clip-applying machine that used a pusher with a rounded tip to displace one clip relative to another and to cause fracture between interconnections on adjacent protrusions. Such technique will not work well with a ductile material, such as copper. As shown in Figure 2, strip 110 can be stored as a roll 150 in order to facilitate dispensing of individual clips 112 from strip 110. For example, roll 150 can be incorporated into a rotary unwind apparatus of a clip dispensing machine that has opposed cutting edges that are driven together to co-act and sever individual clips 112 from strip 110 of roll 150. Figure 3 illustrates an enlarged detailed view of a selected portion of strip 110 showing a plurality of adjacently formed clips 112. Figure 4 further illustrates such construction taken along section line 4-4 of Figure 3. As shown in Figure 3, strip 110 is formed from a single continuous piece of material, such as polypropylene or some other previously mentioned suitable material. One technique involves cutting strip 110 from a relatively thin sheet of material. Another technique involves stamping, machining, or laser cutting strip 110 from a sheet of material. Other techniques involve cutting strip 110 between a pair of intermeshing rotary cutting dies. In the forming process, individual clips 112 are contiguously joined together by way of a narrowed strip, isthmus, or web 152. Each strip 152 is provided along a central, or medial portion of strip 110, and a pair of laterally positioned slots 154 and 156 are provided immediately adjacent opposite sides of strip 152, respectively. Accordingly, slots 154 and 156 cooperate to define strip 152 as being a relatively narrow strip between adjacent clips 112, compared with a lateral width of strip 152. Each clip has aperture 114 cooperating with a respective bag receiving passage 116 which is provided between a pair of opposed front surfaces 118 and 120. Front surfaces 118 and 120 terminate in a converging pair of fingers 128 and 130 so as to provide a relatively narrow gap, or passage 116 into aperture 114 for receiving a bunched-up open neck portion of a flexible bag, such as a plastic bag. As shown in Figure 4, individual clips 112 within strip 110 are shown with relatively narrow bag receiving passage 116 entering into aperture 114. Likewise, the relative scale of slots 156 are shown with respect to a selected one of clips 112. According to the construction depicted in Figures 2-4, it is understood that bag closure clips can be manufactured in a continuous strip and stored in a roll from non- frangible materials, such as biodegradable materials. Suitable biodegradable materials include paper, paper products, cardboard, and other traditional biodegradable materials. However, such a strip of closure clips can also be constructed from biodegradable plastics, such as biodegradable thermal plastics. Once such plastic is Polyactide (PLA), a biodegradable thermal plastic. Another material comprises Polyactic acid binder for joining together cellulose and other biodegradable materials. Even another material includes poly vinyl alcohol (PVOH). Even another material includes biodegradable polyester amide. An even further product includes a biodegradable polymer which is capable of being thermoformed. According to the construction depicted in Figures 2-4, a plurality of closure clips are integrally formed in a strip with a central tab integrally provided between adjacent clips. According to one construction, the central tab has a width of at least about 10 percent of the width of the strip. In some cases, the central tab has a width from about 20 percent to about 30 percent of the width of the strip. In even further other cases, the strip has a width of greater than about seven percent of the width of the strip. Furthermore, some further desirable constructions provide a central tab with a width of about 25 percent of the width of the strip. Construction of the central tab, or web, is configured to enable severing of clips from a strip using a pair of coacting cutting edges, such as cutting edges provided between a pair of complementary cutting dies. In contrast, prior art techniques utilize a finger that bends one clip relative to another in order to impart fracture of the frangible interconnecting webs provided between adjacent clips. The provision of such a central tab or web, which is configured to be cut between a pair of coacting cutting edges, enables the use of non-frangible materials, such as polypropylene, in constructing a strip of closure clips. Furthermore, such construction enables utilization of biodegradable material which tends to not be brittle or frangible, and which cannot be readily fractured using the prior art techniques discussed above. Accordingly, a strip of closure clips can be formed from a resilient plastic material, or from a contiguous sheet of biodegradable material. Furthermore, paper and paper products can be used to formulate such a strip of clips. For example, the provision of materials with a high content of wood fiber within paper or cardboard, along with an adhesive binder, enables the production of a fairly rigid strip of clips. Such strip of clips can be severed along the central connecting tab by a pair of coacting cutting edges by a clip cutting machine that is used to apply and sever clips from a strip during a bagging operation for products such as thermoformed articles, as well as food products.