NATURAL SCIENCES OF PHILADELPHIA. 75 



articulation. Superior processes of the caudal vertebrae not elongated ; hypa- 

 pophyses bifid. 



Char, not universal. Top of head plated. Belly protected by broad plates. 

 Tail cylindrical. Penis simple.* 



The Chersydrus granulatus has a compressed tail somewhat resem- 

 bling that of the sea snake's, and adapted to habits similar in many respects. 

 Yet even in external form it bears a greater resemblance to that of some of 

 the Boas, having a prehensile character. A comparison of the caudal verte- 

 brae of this serpent and the Hydrophis pelamidoides shows the follow- 

 ing differences : In the latter the neural spines are slender and greatly 

 elongated, and the pleurapophysesf slender, elongated, and but little di- 

 verging. The "appendages" of the latter, which in all serpents appear in 

 the last dorsal and first caudal vertebrae, and are doubtless the homologues of 

 the re-verted processes on the ribs of birds, partake of the same nature. 

 The hypapophyses are similar to those of the dorsal vertebras, being undi- 

 vided, with the exception of those upon the first two vertebrae, whose pleura- 

 pophyses are destitute of the appendage. These are slightly bifid. 



In the Chersydrus the structure is entirely that of the Colubers. The neural 

 spines are short and compressed ; the pleurapophyses short and diverging ; 

 and the hypapophyses bifid, and their lateral moieties separated. Thus in 

 addition the difference in the armature of the mouth, the structure of the tail 

 separates this genus from the sea snakes. Its position appears to us to be 

 between the Homalopsinse and Boidae, connected to the latter by Xenoder- 

 mu s Reinwt., as indicated by Dumeril and Bibron. 



CALAMARIN^E. 



Calamaeia Boie. Type C. L i n n a e i . 

 Isis, 1827, p. 519. 



65. C. Gervaisii D. B., vii. p. 63. 



Four sp. Philippine Is. Mr. Cuming. 



One (young). " " 



Aspiduea Wagler. Type A. brachyorrhos. 

 Naturlich. Syst. der Amphib. p. 191. 



66. A. brachyorrhos, Gthr. Cat. Brit. Mus. 14. Scytale brachyorrhos 

 Boie. Isis, 1827, 517. A. scytale, D. & B.,'vii. 178 ("Wagler" D. & B. 

 et Gthr.). 



One sp. Ceylon. Mr. Cuming. 



67. A. trachyprocta nobis. 



Form stout, not elongate. Tail short, thick, one-eighth of total length. 

 Scales in fifteen rows, broad, not imbricate, smooth. The scales in the four or 

 five rows each side of the anus, for a distance of from four or five scales in 

 front to nine or ten behind the anus, are marked each with a small recurved 

 tubercle near the anterior border. Anal shield entire. Superior labials six, last 

 largest ; the eye resting on the fourth. Inferior labials five. Posterior pair of 

 geneial shields separated by a central complementary plate. Head shields simi- 

 lar to those of A. brachyorrhos, except that the occipitals are more 

 rounded posteriorly, and the lower postoculars larger. Gastrosteges 135, 1 

 entire anal, 21 entire urosteges, and a small central postanal plate. Total 

 length 8 in. 21. Tail 1 in. 



Coloration. Upper surface of head and body deep brown, becoming lighter 

 on the third and fourth longitudinal rows of scales, and contracted on the tail 

 to a narrow median vitta. A blackish brown band passing through the eye, 



*CoronelIa can a is one exception, fide Schlegel. 



f These were inadvertently alluded to, Proceedings, 1859, p. 333, as "haemal spines." 



I860.] 



