TRANSACTIONS OF SECTION D. 



1Q5 



I ii 



with anturior margins united. Astragalus witliout ascending process. Five digits 

 iu manus and in pes. 



(n'lU'ia : Zandudon, ? Terafomurtis. 



4. Family Auchimin-ichr, \'ertebr.TD l)i-concavo. Tubes rod-like. Five digits 

 in manus. and three in pes. 



(Jt'iMTa; AnvhiMuirun (Mi\i/u(lact>//m), ? Jifit/ii/gnrit/iuit,? Clrpsysmirus, Palepo- 

 saum-1, Thccodontosmu'UK, 



Sub-Order C"(KI,ukta. 



h. Family Cfclurnhe. Vertebras and bone.s of .skeleton pneumatic. Anterior 

 cervlcals convexo-concave ; remaining vertebras bi-conciive. Cervical riljs co- 

 ojsified with vertebr.T, Metatarsals very long and slender, 



Genu.s : C'alurns. 



Sub-Order Co.MrsoGXATii.v. 



0, I'amily CiDiipsot/nnt/udfp. Cervical vertebnc convexo-concave; remaining 

 vertL'brje bi-concave. Three functional digit.s iu manus and in pe.s, Iscliia with 

 lonii .'iymphyjis on median line. 



Genus : Cuiin>so(in(ithm, 



Sub-Order Ckh.vtosauuia. 



7. Family ('<•>•(( fomnridf/'. Horn on skull. Cervical vertebrre plano-concave; 

 remainin;r vertebru! bi-concave. Pul)es slender Pelvic bones coo.ssified. Osseous 

 dermal plates. Astragalus with ascending process. Metatarsals coossiilcd. 



(lenus : Cerafosaunis. 



The four orders defuied above, -which the author first established for ths recep- 

 tion of the American Jurassic Dinosaurs, appear to be all natural grr dps, well 

 marked in general from each other, llie European Dinosaurs from deposits of 

 corresponding age fall readily into the same divisions, and, in some cases, 

 admir,il)ly supplement tiie series indicated by the American forms. The more 

 importaiir remains fromotlier formations in this country and in lOurope, so far as 

 their characters have been made out, may likewi.se be referred with certainty to 

 the same orders. 



Tlie three orders of Herbivorous Dinosaurs, although widely dilVerent in their 

 t\-pical forms, show indications of approximation in some of their aberrant genera. 

 Thi' 'Saiiropodn, for example, with Atlanfosnurus and Bronfosnurns, of gigantic size, 

 for their mo.st characteristic members, liave in Morosaurus a branch leading 

 towards the Stef/osrcuria. The latter order, likewise, although its type genus 

 represents in many respects tins most strongly marked division of the Dinosaurs, 

 lias in Scclidosaarus a form with some features pointing strongly towards the 

 Ornithiipiidd. 



The Carnivorous Dinosauria now best known may all be placed at present in a 

 single order, and this is widely separated from those that include the herl)ivorouH 

 forms. Tlie three sub-orders here defined include very aberrant forms, which 

 sI'iOw many points of resemblance to Mesozoic ))ir(ls. Among the more fragment- 

 ary rt;mains belonging to this order, this resemblance appears to be carried much 

 furtlier. 



Tiie Amphisanrldat and tlie, Zanchdontidcp, the most generalised families of tlie 

 Diiiusauria, r.re known only from the Trias. The typical genera, however, of all 

 the orders and sub-orders are Jurassic forms, and on these especially the present 

 clas.'^llipat ion is based. The lladroi^auridM are the only family confined *o the 

 ^'retaooous. Above this formation there appears to beat present no satisfactory 

 evidt'iiee of any Dinosanrin. 



The peculiar orders Ilnllnpnda and Aitomnrin includf^ carnivorous reptiles 

 Vuieh are allied to the Dinnsanrin, but they difl'er from tliat group in some of its 

 most characteristic features. In the former genus, the entire limbs are crocodilian, 

 and this is also true of the dermal covering. In hoth of these genera there ar(> but 

 tv/n sacral vertebra;, but this may be the case in true Dinosaurs, especially from 



t I 



