250 [October, 



ab. sc. 146 ; a single prteanal, 38 sub-caud. followed by 7 bifid near the posterior 

 extremity of the tail ; in the Pottsville specimen, 148 ab. sc. 1 bifid near the 

 anus, 21 single and 20 bifid plates at the end of the tail. In a 2d 142, ab. sc. 



1 bifid near the anus, 25 single and 21 bifid. la all the specimens the sub-cau- 

 dal scales are single anteriorly and bifid posteriorly. The Trigonocephali, like 

 the Crotali, have a deep pit between the eye and the nostril, in which they 

 differ from the Vipers. They have plates upon the head, unlike Bothrops and 

 several other genera, and are destitute of rattles. This serpent was first de- 

 scribed by Linnceus under the name Boa contortrix ; and afterwards by Pali- 

 sot de Beauvois, who calls it Angistrodon mokeson. It has been placed in no less 

 than five different genera, viz. : Boa, Angistrodon, Cenchris, Scytalus, and Tri- 

 gonocephalus, with three diS'erent specific names. 



Habitat. This serpent has a very wide geographical range. From N. Eng- 

 land to Florida, and the shores of the Atlantic to Alleghanies, (Holbrook) Ohio, 

 Penn., S. Carolina, Louisiana, Texas, (B. and G,) 



Crotalus conpluentus. 



There is one specimen of Crotalus, which corresponds sufficiently well with 

 Say's description of Crotalus confluentus. The spots are more crowded together 

 anteriorly than in the specimen described in Sitgreave's report ; the interspaces 

 between the first fourteen being much more indistinct than between those 

 which follow, especially the first seven which present the appearance of narrow 

 white transverse bands ; they are confluent only to a slight extent. Total 

 length including rattle, 1 foot 8^ inches ; of tail including rattle 1 inch 8 lines ; 

 of rattle 9 lines ; (4 rattles and terminal appendage) of head 1 inch, breadth 

 f ; 25 or 27 rows of scales. 178 ab. sc, a single praeanal, 1 bifid, 14 single and 



2 bifid sub-caudal, the last near the rattle ; circumference 2 inches. 40 brown 

 subquadrate spots, more or less marginated, may be counted upon the back and 

 four or five upon the tail; the last nine or teu have more the appearance of bars 

 than regular blotches. A much larger Crotalus than the above is found in 

 California, of which an excellent figure is given in Capt. Marcy's Exploration of 

 Red River, pi. 1, under the name of Crotalus confluentus. We have several 

 in the collection of the Academy, presented by Dr. Heermann, of which a 

 notice will be given in the forthcoming volume of the Pacific Railroad report, 

 under the direction of Capt. Williamson. These are of a yellowish color be- 

 neath, with brownish maculations ; the subquadrate spots upon the back a deep 

 brown bordered with orange. One of these specimens measures more than 3 

 feet in length ; 23 rows of scales. The predoninating color in the specimens, ex- 

 cept that of the dorsal subquadrate blotches, is sulphur yellow. The name of Cro- 

 talus Lecontii might perhaps with propriety be given to this species from Cali- 

 fornia, and that of confluentus be retained for the smaller crotalus with quad- 

 rate blotches, from Missouri and Kansas. The serpent figured in the Explora- 

 tion of Red River, has more the general appearance of the former, and the shape 

 of the rattle corresponds, this in confluentus tapering to a point ; and not quad- 

 rangular as in the larger animal. 



RANIDiE. 



There is in the collection a specimen of Rana halecina, which does not differ 

 in any important particular from the R. halecina found in the neighborhood of 

 Philadelphia, unless it be that in the latter the internal nares appear to be 

 larger, and the tongue more narrow. The vocal vesicles are quite distinct, the 

 pores upon the orbit conglomerated and very apparent ; others are observed 

 upon the neck and anterior part of the back, and a band extends along the 

 upper margin of each flank, from the posterior angle of the eye to near the 

 thigh; Dumeril and Bibron state, that it is with some doubt that they separate 

 this species (the halecina,) from palustris, but admit that they are, and they are 

 no doubt distinct. They are both very common in the neighborhood of Phila- 

 delphia. The Rana halecina has vocal vesicles, the palustris has none ; the 



