no 



it was more like a Urodele form, But the vertebrae, interpreted by the zygapophyses 

 were procoelian, not opisthocoelian, the diapophyses were long and flattened from above, 

 and there were elevated neural spines. Thus, while the elongate curved ribs do not differ 

 much from those of some Labyrinthodontians, the vertebrae and other bones are of 

 entirely different type. 



RHABDOPELIX LONGISPINIS, Cope. 

 Pterodaetylus longispinis, Cope, Proc. Academy Nat. ScL, Phila., 1800, p. 200. 



Recognizable portions of the cranium are unfortunately wanting, except a toothed piece, which may belong to 

 some peripheral bone, or to the mandible. This is much crushed; the teeth are slender, straight— conic, with 

 expanded liases, from the centres of which the colored substitute for bone is wanting, as though they had been hol- 

 low pedestals. The teeth show no trace; of the mode of attachment, and they may be continuous, and therefore mere 

 processes. Intervening edge very straight. 



Greatest depth of bone, 

 Length, embracing four teeth, 

 Length of tooth, 



Lines. 

 'A. 

 2.5 



.04 



The distance between the teeth is nearly equal to the length of each tooth. 



Of the vertebrae (here are innumerable portions, fractured in many directions; some exposed condyloid surfaces; 

 numerous vertical views, and thirteen complete or nearly complete profile views, from different parts of the vertebra] 

 column. The latter may lie divided into those with, and those without, elevated neural arches. To the latter 

 belong, perhaps, some elements more elongate than any other vertebrae, and with centra of larger diameter, on which 

 no apophyses were visible; but from one extremity a centrum-like prolongation with terminal convex condyle, proxi- 

 mally slightly constricted. As these have been destroyed in the process of bringing out other pieces, their place and 

 nature arc problematical. They have considerable resemblance to the cervical vertebrae of Pterodaetylus longiros- 

 tris, as figured by Cuvier and Von Meyer. The other vertebrae, with depressed neural arch, being probably caudal, 

 will be described later. 



Of vertebrae with elevated neural arch, there arc nine profiles, of which four have the neural spine a carina less 

 elevated, and live have much elevated apophyses. In all of these the; positions of ball and socket, and of the 

 different zygapophyses, are very distinct, None of them have hypapophyses, The centrum bearing the posterior artic- 

 ulation or ball is considerably produced backwards and constricted slightly in front of the ball, though the diameter 

 of the hitter is small, both it and the anterior socket being evidently transverse. The posterior or despectant zyga- 

 pophysis extends as far over the centrum as its condyloid extremity, in one vertebra farther, while a laterally 

 expanding ridge marks the anterior or surspeefcant zygapophysis. These vertebral! are perhaps anterior dorsals, 

 while those with elevated neural spines are median dorsals and lumbars. If this identification be correct, then 

 vertebrae with more compressed centra, hereafter mentioned, are probably lumbars. 



Length centrum, supposed anterior dorsal (No. 8), 



" neural crest, 



" at base neural arch, 

 Depth, total, 



" centrum from anter. zygapophysis, 

 " " anterior to condyle, 



Linen. 

 4. 

 ;!. 



0.75 



Of the supposed dorsals, one differs from the rest in its less elevated neural arch, and in its long narrow neural 



