338 PROCEEDINGS OP THE ACADEMY OP 



the rows between the nasals varies from two to four in the first, from four to 

 six in the second ; that the number of rows of supralabials varies from two 

 to three ; the rows of scales on the body vary from 24 (the number attributed 

 to L e co n te i) to 26 ; that the rostral plate is often half bordered, sometimes 

 not at all. 



17. C. horridus Linn. Syst. Nat. i. p. 214, Edit. 1760. Cuvier, Regne 

 Animal, ii. p. 78, 1817. Crotalus durissus Daud. Hist. Rept. v. 304, 1803. Also 

 of Holbrook, Dumeril and Bibron, Baird and Girard. Crotalus atricaudatus 

 Daudin and Wagler. Uropsophus durissus Gray, Cat. Brit. Mus. Urocrotalon 

 durissus Fitzinger, 1843. 



Nine spec. Penna. Drs. Mitchell and Rand, and Mr. J. H. Slack. 



One " 



Ten " 



No. 47 (Penna.,) dark variety. The black double rhombs become confluent 

 upon the plants anteriorly, enclosing the lighter ground, which thus forms a se- 

 ries of oblong spots. Posterior rhombs all confluent into transverse black bands. 

 Gastrosteges clouded with brownish black. Nos. 48 and 49 are intermediate 

 between this and the ordinary variety. 



The remaining species of this genus are : 



C. mo loss us B. & G., Catalogue Serp., Smithson. Inst. p. 10. A very 

 distinct species. 



C. or n at us Hallowell, Pacific Rail Road Report, x., Parke's Explorations 

 p. 24. 



C. t i g r i s Kennicott, U. S. and Mex. Boundary Survey Reptiles, p. 12, pi. 4. 



C. 1 u g u b ri s Jan, Rev. et. Magasin de Zoologie, 1859, p. 156. This seems 

 to be most nearly related to C. lucifer B. & G. 



Teleukaspis nobis. 



Head triangular, depressed, covered above with small scales. Muzzle prom- 

 inent, bordered by a series of small scales ; a large superciliary plate on each 

 side as in Bothrops. Urosteges one-rowed ; tail without rattle. 



The absence of a rattle distinguishes this genus from Crotalus, and the en- 

 tire urosteges from Bothrops. Its natural situation appears to be between 

 them. The two species which we have seen are both small and widely differ- 

 ent from each other. 



18. T. Schlegeli nob. Trigonocephaly Schlegeli Berthold, Abhand- 

 lungen der Koniglichen Gesellschaft der Wissenschaften zu Gottingen, iii. 

 p. 13, 1847. Jan, Rev. et Mag. de Zoologie, 1859, p. 155. 



Two Spec. Cocuyas de Veraguas, N. Granada. Mr. R. W. Mitchell. 



Since the time of its description in 1847, this rare and curious serpent has been, 

 as far as we are aware, unnoticed by authors. As Berthold's description is brief, 

 we subjoin the following : 



Snout rounded, depressed, its plane forming an acute angle with that of the 

 rostral, which is slightly concave. Scales on the head tuberculous or carin- 

 ate, as are also the supralabials and temporals, the latter excessively. A series 

 of small tuberculous scales between the superciliary and orbit, two of which 

 are prolonged into compressed horn-like appendages, which are erect and flexi- 

 ble. Scales bordering the muzzle with their outer borders free and recurved. 

 Nasal plate large, the nostril pierced in the centre. Lachrymal fossa large. A 

 slender undivided subocular. Superior labials nine, the third longest ; eye 

 over third and fourth. Inferior labials thirteen. Geneial scales imbricate, 

 acute, some of them carinate. Scales of the body thin, acute, much imbricate, 

 in 24 or 25 longitudinal rows, all carinate except those next the gastrosteges. 



[Dec. 



