52 AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA 



Revised description: 



1. Small, not exceeding 500 centimeters in length. 



2. Occipital condyles separate. 



3. Otic notch represented by a large fenestra. 



4. Parasphenoid reduced to a slender rod. 



5. Two functional sacral ribs. 



6. Dorsal armor composed of the laterally expanded neural spines, 



smooth above and overlain by narrow dermal plates, as wide 

 as the body and alternating with the neural spines in position. 



7. Clavicles and interclavicle small, without sculpture. 



8. Cleithnim very large. 



9. Unknown. 



10. Unknown. 



11. The two halves of neural arch united. 



12. Intercentra thick constricting the notochordal space. No pro- 



cesses on the intercentra for the ribs. 



Genus DISSORHOPHUS Cope. 



Cope, Dtssorhophus, Am. Nat., vol. xxix, 1895, p. 998. 



Otoceelus, Am. Nat., vol. xxx, 1896, p. 398. 



Oiocalus, Proc. Am. Phil. Soc, vol. xxxv, 1896, p. 124. 

 Williston, Dtssorhophus, Journ. Geol., vol. xviii, No. 6, 1910, p. 526. 



Type: A fragment of the vertebral column. No. 4593 Am. Mus. Nat. 

 Hist. Cope Coll. From Texas. 



Original description: The specimen "consists of a portion of the skeleton, 

 which includes ten consecutive vertebrae and their appendages, of the rhachi- 

 tomus type, similar in general to those of the Trimerorhachis. The genus 

 differs from Trimerorhachis in this important respect. The neural spines 

 are elevated, and the apex of each sends a transverse branch which extends 

 in an arch on each side of the ribs. These spinous branches touch each other, 

 forming a carapace. Above and corresponding to each of them is a similar, 

 dermal osseous element, which extends from side to side without interrup- 

 tion on the median line, forming a dermal layer of transverse bands which 

 correspond to the skeletal carapace beneath it. To this remarkable genus 

 I propose to give the name Dissorhophus. It is a veritable batrachian 

 armadillo." 



In ihe description of the genus Otocoelus, Cope says in the "American 

 Naturalist": 



"Suspensorium directed anteriorly, except at free extremity; nostrils 



lateral Otocalout 



Suspensorium directed posteriorly; nostrils vertical Conodectes 



"Otoccelous has the following characters: Intercentra present. Teeth 

 subconical. Mandible not projecting beyond the quadrate. Clavicle ex- 

 panded at both extremities, overlapping the episternum. Scapula with a 

 proscapular lamina. Ribs transversely expanded, not united by suture with 

 each other, alternating with the dermal bands. Limbs well developed." 



In the "Proceedings of the American Philosophical Society" he gave 

 a much fuller description: 



"Teeth with subconic crowns. Mandibular ramus not produced poste- 

 rior to the quadrate. Superior cranial bones strongly sculptured. * * * 



