NATURAL SCIENCES OF PHILADELPHIA. 



317 



the submedian perforation. Its tibial face appears to have been rounded, not 

 angulate. The tibia presented an ascending ridge, to the face of which the 

 ascending apophysis was applied ; in the Laelaps aquil unguis there is no 

 ridge, the apophysis reposing in a slight concavity. This apophysis, like the 

 slender portion of the fibula, is composed of dense bone. 



Cuvier describes at the same time a bone of which he says, " il ne serait pas 

 impossible que 1'os (fig. 39) fut la tete superieur du perone du pied que. je viens 

 de decrire." This piece has a shank compressed at right angles to the direction 

 of its head, a form so unlike the fibula? of known Dinosauria, including Mega- 

 losaurus and Laelaps, as to render its pertinence to the animal possessing the 

 forementioned tibia, to say the least, very doubtful. 



The direction of the condyle indicates the articulation of the tarsal elements 

 to have been at a considerable angle with the shank of the leg, and that the 

 animal was entirely plantigrade, and was unable to extend the foot in line with 

 the lower leg. The animal's weight was no doubt shared by another tarsal 

 bone, besides the astragalus, owing to the anterior position of the former. 



In most known Dinosauria the relations of tibia and fibula are similar to 

 those in the modern Lacertilia. It would appear then that this class existed 

 under two ordinal modifications ; the first, including Scelidosaurus Ow., Hylaeo- 

 saurus Mant., Iguanodon Mant., and Hadrosaurus Leidy, may be called the 

 Okthopoda ; the second including Laelaps Cope, and probably Megalosaurus 

 Buckl., may be termed the Goniopoda. 



November 20ih. 



The President, Dr. Hays, in the Chair. 



Thirty- seven members present. 



The following was offered for publication : " Descriptions of some 

 new species of Diurnal Lepidoptera." By Tryon Reakirt. 



November 27th. 



The President, Dr. Hays, in the Chair. 



Forty-two members present. 



On favorable report of the Committees the following were ordered 

 to be published : 



Fifth Contribution to the HEPPETOLOGY of Tropical America. 



BY E. D. COPE. 



The following species, previously unknown to the scientific system, are 

 selected from the collections made at different points in Mexico by the 

 esteemed correspondents of the Smithsonian Institution, Drs. Arthur Schott, 

 Francis Sumichrast, Berendt, and Major. 



OPHIDIA. 



Himantodes tenuissimus m. sp. nov. 



Vertebral series of scales small, like the rest, altogether in seventeen 

 rows. Head broad, very obtuse, prenasals approaching each other ; loreal 

 subquadrate ; preorbitals 2 or 1, postorbitals narrow, two. Superior labials, 

 eighth, fourth and fifth, sometimes third in' orbit. Frontal anterior suture 

 longer than lateral, which converge behind; length of shield three-fourths 

 common suture of parietals ; temporals 1 or 2 3. 



18G6.] 



