CADUCIBRANCH1ATA. 35 



f. Canthus rostralis distinctly marked. 



Texanum. (io) 



g. Back and tail with gray rings or bands. 



CINGULATUM. (19) 



g. Back plumbeous: sides spotted. 



MICROSTOMUM. (8) 



h. Costal grooves 12. (i) 



h. Costal grooves 11: vomerine series of teeth 3. 



BICOLOR. (11) 

 i. Tail shorter than the body: canthus ros- 

 tralis wanting, (j) 

 i. Tail exceeding the length of the body: can- 

 thus rostralis distinct xiphias. (15) 



j. Vomerine teeth in a nearly continuous 



line, (k) 

 j. Vomerine teeth in four distinct patches. 



trisruptum, (14) 



k. Nares inequidistant: yellow spots 



usually small . . . tigrinum. (3) 



k. Nares equidistant: yellow spots 



large mavortium. (6) 



1. Plantar tubercles indistinct, or none, (m) 

 1. Plantar tubercles two distinct. . . .obscurum. (13) 

 m. Costal grooves 12 or more, (n) 



m. Costal grooves 11 paroticum. (17) 



n. Vomerine series of teeth 3, extending 



to exterior of nares. (o) 

 n. Vomerine series of teeth 2, extending 

 only to interior of nares. 



ATERRIMUM. (l8) 



o. Width of head 4.5 to 5 times the 

 length to groin. 



Jeffersonianum. (4) 



o. Width of head 5.5 to 6 times the 



length to groin. platinenum.(i6) 



