1854.] 99 



Fam. VIPERIDtE. 



Gen. Brachycranion, Hallowell. 



Gen. char. Head short and thick, covered with seven plates, exclusive of the 

 rostral, viz., one pair of frontal, a vertical, two supra-orbitar, and two occipitals, 

 one ant-orbitar and one post-orbitar ; margin of orbit formed by supra-ocular, pos- 

 terior and anterior oculars, and superior margin of fourth labial plate. Subcaudal 

 plates single; palatal, but, with the exception of the fangs, no mandibular teeth. 



Brachycranion corpulentum. 



Sp. char. Occipitals subquadrangular ; four supero-labials ; one large tempo- 

 ral plate immediately behind post-ocular ; scales smooth, quadrangular, 25 rows; 

 color shining black above, brownish beneath ; 182 abdominal scuta ; 25 sub- 

 caudal. 



Dimensions. Length of head i an inch, breadth 5 lines ; length of body 1 foot 

 6 inches ; of tail 2 inches ; circumference 1 inch 8 lines. 



Habitat. Liberia, W. coast of Africa. Presented by Dr. Ford to the Academy. 



Gen. observ. The vipers among venomous serpents are characterized chiefly 

 by the absence of forsettes behind the nostrils, and the presence of a double row 

 of plates under the tail. In the greater number, the head is covered with scales 

 as upon the body ; in others there are also plates of various forms, and irregularly 

 disposed, as in Vipera berus, while others have upon the head smooth and regu- 

 larly formed plates, like those of Coluber and the genus Sepedon of Merrem. In 

 others the subcaudal plates are bifid toward the anus, and single near the ex- 

 tremity of the tail, or alternately single and bifid as in Acanthophis. 



Bungarus, a genus of Colubriform venomous serpents inhabiting Asia, has a 

 dorsal row of hexagonal scales larger than the others, with nine plates upon the 

 head and single plates under the tail. Elaps has nine plates upon the head, but 

 the plates under the tail are bifid. In the animal under consideration there are, 

 as above stated, but seven plates upon the head exclusive of the rostral, there 

 being but one pair of frontals (two in Elaps, Acanthophis and Bungarus) and 

 single plates under the tail. These characteristics, with the peculiar form of 

 the head and the presence of fangs, are such as to give it a distinct generic cha- 

 racter different from those of any of the serpents with which I am acquainted. 

 The appearance of Brachycranion corpulentum is very repulsive. Since the 

 above was written, I have observed in the work of Dr. Andrew Smith,* on the 

 Zoology of South Africa, the description and figure of a reptile which resembles 

 the one just described, to which the name Atractaspis Bibronii has been given. 

 The body in Atractaspis Bibronii is much more slender, is longer, but the tail 

 is shorter. The shape of the head in the figure is very different, giving one the 

 impression of a harmless serpent, as Dr. Smith at first supposed it to be, that of 

 the other induces at once a strong suspicion of its venomous character. There 

 are but twenty rows of scales in Bibronii, and the general color of the body and 

 tail is intermediate between blackish green and orange colored brown. The 

 fangs in Corpulentum also differ from those of Bibronii in their dimensions, 

 being not more than half the length of those in the figure of Bibronii. Like them, 

 they do not appear to be capable of complete erection. Upon the upper surface 

 of the tail in Corpulentum, along the median line near its middle, is a row of six 

 broad scales and four others near the tail, somewhat similar in appearance to 

 those upon the back in Dipsas. 



Cham.eleo gracilis, Hallowell, Journal Acad. Nat. Sc. vol. viii. pi. 18. A 

 good species. It differs considerably in its general appearance from Chama?leo 

 dilepis of Leach, of which there are three specimens in the collection presented 

 by Dr. Henry A. Ford, of Liberia. One of these on being opened was found to 

 contain more than a dozen eggs. I thought at one time that possibly Ch. gra- 

 cilis might be the female of Ch. dilepis. 



* Zoology of South Africa, by Andrew Smith, M.D., Reptiles, pi. 71. 



