A MONOGRAPH OF THE SEA-SNAKES (HYDROPHIIN). 195 
(cb) Costals in midbody 36 to 43. ‘Two super- 
posed anterior temporals. Prefrontal 
touching no labial. . Ee A 
(d') Costals in midbody 37 to 54. One large 
anterior temporal. Preefrontal touching 
and labial ss oe .. torquata. 
(e6) Costals in midbody 42 to 53. ‘wo super- 
posed anterior temporals.  Preefrontal 
nigrocincta. 
touching 2nd labial Pe .. cerulescens. 
(f®) Costals in midbody 47. One large anterior 
temporal. Prefrontal touching no labial — bituberculata. 
(ct) Ventrals 375 to 531. 
(a) Anterior costals 25 to 36. Two superposed 
anterior temporals. Ventrals 375 to 397 cyanocincta. 
(6°) Anterior costals 25 to 41. One large 
anterior temporal. 
(a’) Anterior costals r to 9 less than pos- 
terior. Ventrals 376 to 438 .. torquata. 
(08) Anterior costals Io to 22 less than pos- 
terior. Ventrals 376 to 531 .. fasciata. 
(cb) Anterior costals 48 .. 50 .. neglecta. 
