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Show 1.20 DOMESTIC RABBIT.'. CHAP. IV. some of tho largcRt skulls of tho lop-cared this line was plainly bowed ' . . llif 1 molar tooth on each inwards. ln one spccuuon tl10ro was an ac c .wna . ' ''J··te c>f tho upJ)Cl' J·a,w bctwe n tho molars and premolars; but these tt~~o "' · ' ·1 t 1 · n molars Jllfl teeth clid not rorrcsr oncl in si7.c; and as no roc en las seve ' ' i;; merely a mollstrosity, though a curious one. . . of which 'l'ho five other RkuliR of common domcstJO rahlnts, s.omo approach in sit~o the abovo-deRerihod lnrp:oRt skulls, w~ulst tho oth?rs xcecd unt little tho. 0 or tho wild rabbit, are only worth notwo as prcscptmg 1 . t d t' · ll tl 1o alwvO-Sl1CCificd differences between tho s.·knlls ~t per oc grn. a 1on m a · ' . . 1 . . ·1 ·I' 1 of tho largest lop-cared and wild rabb1ts. I~ n.ll, howovc~ '.:, IO s:1P1.a~or J~ a plates aro rather larger, and in all tho audJtory meatus. JS largo:, n.t co'?-fonnity with tho increased size of tho cxto~·nal cm·s, than m tho w1ld r~bb1t. Tho lower notch in tho occipital foramen ill some was not so deep as ill tho wild, but in all five skulls tho nppcr notch was well dclvclllop~d .. t li t Tho skull of tho A n.fJoru rabbit, like tho latter fi vc sen s, 1s m C1'IDIX a o in general proportions, and in most other characters, bc~wccn thoso of tho larrr st lop-cared and wild rabbits. It presents only one smgular character: th~1gb con idcrably longer than tho skull o~· tho wild, tho. breadth moa~Lll' d within tho posterior snwa-orbital fissures JS nc~rly a tlmc~ loss than m t~10 wilcl.. Tho ·lmlls of tho silve?·-grf'y, and cli£nchttla n.nd Jhmalnyrm rabh1ts arc more elongated than in tho wild, with broader supra-orbital pl11tes, but differ little in 11ny othe1· respect, excepting thn.t tho upper and lower notches of tho occipital foramen arc not RO deep or so well developed. Tho skull of tho Moscvw rabuit scarcely differs in any rcRpcct from that of the wild rabbit. In tltc Porto Santo feral rabbits tho supra-orbital plates arc generally narrower and more pointed than in our wild rabbits. As some of tho largest lop-cn.rcd mbbits of which I propn.rcd kclctons wore colouxcd almost like hares, and as those latter animals and rabbits have, as it is affirmc l, boon recently crossed in Franco, it might be thought that some of tho n.bovc-dcRoribcd characters had b on derived from a cross n.t a remote period with tho hare. Oonsc(]ucntly I examined Rkulls of tho hare, bnt no light could thus be thrown on tho peculiarities of tho skulls of tho. larger rabbits. It is, however, an interesting fact, as illustrating the law that varieties of ono species often assume tho characters of other species of the same genus, that I found, on comparing tho skulls of ton species of hares in the Briti ·h Museum, that they diff rod from each other chiefly in tho very same points in which domestic rabbits vary,-namcly, in general proportions, in tho form and size of tho supra-orbital plates, in tho form of tho free end of tho malar bono, and in tho line of suture , oparating tho occipital and frontal bonos. Moreover two eminently variable characters in the domestic rabbit, namely, tho outline of tho occipital foramen and tho shape of tho "raised platform" of tho occiput, were likewise variable in two instances in tho same species of hare. Ve1'tebm'.-Tho number is uniform in all tho skeletons which I have examined, with two exceptions, namely, in one of tho small feral Porto Santo rabbits and in one of tho largest lop-eared kinds; both of these had as u.·un.l seven cervical, twelve dorsal with ribs, but, instead of seven lumbar, both had eight lumbar vortebrro. This is remarkable, as Gervais gives CIIAP. IV. DIFFERENCES IN THEIR SKELETONS. 121 seven as tho number for th h 1 I apprtrcntly clift'cr b o w o c gonu.s -'cpnR. Tho caudal vcrtcbrro arc difficult t Y tw.o or tJu·?o, but I chd not attend to them, n.nd they 0 count WJth certamty. In. tho first . co I.V I· ca1 vcl'tchra, or atlas, tho anterior margin of the bn om· al a.r ch vanes •a lit't le in WJ' lu-1 spcCJ. mcns, ~mg Oltllcr nearly .·mooth, or furnisl!Cd a wJth. aI small R11Jn·a-mcdian tl t 'd 1 . a an 01 pro-co. A' . lave figmcd a specimen with tho !arp;~st process (n) which I have seen; but 1~ vnll be ~bserved how inferior this is in sJzc and different in shape to that in a !a1:gc Jop-.carcd rabbit. In the latter, tlto m lra-mcdian process . (b) is also proportionall~ much thick?r and longer. Tho alro are a Uttlc squarer m outline. 1'llinl cervical vf'rtebra.-In the wild rabbit ~fi~. ~3, A a) this vertebra, viewed on tho ml~rw~· sn:-facc, has a tJ:ansvorse process, wluc~t JS ~lrc~ted obliquely backwards, and consJSts of a smglo pointed bar; in tho fom'th Fig,~2.:-Atias VerU:lJrru, of natural size; vertebra this process is slightly forked J·n lnfenor surfuce viewed obliquely. th 'ddl Upper flgurr, Wild Unbbit. Lowm· ? illl c. In the large lop-eared rabbits flgur~, Hare-coloured, large, Lop-cllred thJS process (B a) is forked in the tllird vcr- Rllbbit. a~ supra-medtan, atlantmd to bra, as in tho fourth of tho wild rabbit. process; b, mfra median process. But tho thiJ:d cervical vertebrre of the wild d 1 . differ more conspicuously when their antcri~~ 111~-e~red (A b, B b) rabbits pared; for tho extremities of the cu ar surfaces arc com-antcro- dorsal processes in the A B wild rabbit arc simply rounded ~ whilst in tho lop-cared they ar~ ~ trifid, with a deep central pit. b ~~- f''{'1 c · ~. . . b Tho canal for tho spinal marrow fl · · in tho lop-cared (n b) is more elongated in a transverse direction than in tho wild rabbit . and the pa.c;sagcs for the artoric~ a are of a slightly different shape. a These several diifcrcnccs in this vertebra seem to me well do-serving attention. 1 '· Fig. !3.-Third Cervical Vertebra, flf natural 81·z.e 1 wst donal ver·tebra. ~ Its of A Wild :Ra ' ~ Lo~~·r·e .bbit; B. llare-colourcd, large, n ma,l spine varies in length in P ~· d :Rabhtt. a, a, inferior surfuc<' · tho WJld rabbit; being sometimes b, b, anterior articular surfaces. ' vory short, but generally m . th 1 'dorsal· but I h . ~le an 1alf as long as that of the second < ' ave soon lt rn two large l d bb' of tho lcnO'th of that 1. th d d op-carc ra 1ts th1·ec-fourths . o 0 e secon orsal vertebra. Ntntlt mul tenth do?·sal ver-tebrce.-In tho 'ld . bb't th . the ninth vo ·t b · · WI 111 1 e neural spme of I o ra lS Just perceptibly thicker than that of the eighth ; and |