300 COLUBRID. 
112. ATRACTUS. 
Atractus, Wagler, Isis, 1828, p. 741. ' © ww; 
Brachyorrhos, part., Wagler, Syst. Amph. p. 190 (1880). 
Calamaria, part., Schleg. Phys. Serp. ii. p. 25 (1837). 
Rabdosoma, part., Dum. & Bibr. Mém. Ac. Se. xxiii. 1853, p. 440, 
and Erp. Gén. vii. p. 91 (1854) ; Giinth. Cat. Col. Sn. p. 10 (1858) ; 
Jan, Arch, Zool. Anat. Phys, ii. 1862, p. 10. 
Isoscelis, Giinth. 1. e. p. 204. 
Adelphicos, Jan, l. c. p. 18; Bocourt, Miss, Sc. Mex., Rept. p. 5638 
(1883). 
Rhegnops, Cope, Proc. Ac. Philad. 1866, p. 128. 
Rabdosoma, Bocourt, 1. c. p. 588. 
Skull of Atractus crassicaudatus. 
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 ; preocular usually absent, loreal and prefrontal 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. elaps, p. 302. 
Scales in 17 rows; one postocular .... 2. latifrons, p. 303. 
Scales in 17 rows ; two postoculars.... 3. modestus, p. 304. 
