300 



11 a. ATRACTUS. 



Itabdosoma, port., Dum. fy Bibr. Mem. Ac. Sc. xxiii. 1853, p. I Id, 

 and Erp. GVn. vii. p. 1 (1854) ; Gilnth. Cat. Col. Sn. p. 10 (1858) ; 



Jan, Arch. Zool. Anat. Phys. ii. 1802, p. 10. 

 Isoscelis, Giinth. 1. c. p. 204. 

 Adelphicos, Jan, 1. c. p. 18 ; Socourt, Miss. Sc. Mar., Sept. p. 553 



(1883). 



Khegnops, Cope, Proc. Ac. Philad. I860, p. 128. 

 Rnbdosuina, Ilocourt, I. c. p. 638. 



Fig. 22. 



Skull of Atractus crassieaudatw, 



Maxillary short, with 8 to 12 teeth ; maxillary and mandibular 

 teeth decreasing in size posteriorly. Head not distinct from neck ; 

 eye small, with round or subelliptic pupil; nostril between two 

 nasals ; pracocular usually absent, loreal and praefrontal entering the 

 eye. Body cylindrical ; scales smooth, without pits, in 15 or 17 rows ; 

 ventrals rounded. Tail short or rather long ; subcaudals in two rows. 



Central and South America. 



Synopsis of the Species. 

 I. Symphysial shield separated from the chin-shields. 



A. Loreal not more than once and a half as long as deep. 



Scales in 15 rows ; one postocular .... 1. daps, p. 302. 

 Scales in 17 rows ; one postocular .... 2. latifrons, p. 303. 

 Scales in 17 rows ; two postoculars . ... 3. modestvts, p. 304. 



