CROCODILIANS, LIZARDS, AND SNAKES. 947 



Toluca lineata Kennicott. 



GYALOPIUM Cope. 



Gyalopium Cope, Proc. Acad. Nat. Sci. Phila., 1860, p. 243; Proc. U. S. Nat. Mus., 

 XIV, 1892, p. 60.'? ; Bull. U. S. Nat. Mus., No. 32, p. 52. 



Form stout, tail short. Head slightly distinct, large, depressed. 

 Rostral plate acute, its anterior border elevated, its upper surface con- 

 cave. It is produced backward, separating the internasals and pre- 

 frontals. Internasals present, ])refrontals one pair. Nasal confounded 

 with the first labial, a groove from the nostril to the suture of the sec- 

 ond labial. No loreal; its jilace is supplied by the prefrontal. One 

 preocular. Postgeneials rudimental. Scales smooth, anal and sub- 

 caudal scutellai divided. Teeth small, of equal lengths. Pupil round. 



This genus introduces us to a type which is especially Mexican, and 

 which includes the genera Flcimia Gray, Ogmius Cope, and Conopsis 

 Giinther. Stenorhina Dumeril and Bibron is probably so allied, as well 

 as perhaps Geagras Cope. They all have protuberant rostral shields, 

 which are in the first three genera named more or less recurved. 

 Besides the G. cammi, there is but one species of Gyalopium, the 

 G. publium Cope,^ which has been found in Yucatan. 



Rostral plate reaching frontal; 17 rows of scales; seven labials; quadrate brown 

 dorsal spots; larger G.pithliitm Cope. 



Rostral not reaching frontal; 17 rows of scales; seven superior labials; transverse 

 brown bands; smaller (!. canum Cope. 



GYALOPIUM CANUM Cope. 



Gyalopium canum Cope, Proc. Acad. Nat. Sci. Phila., 1860, p. 243. — CoUES, U.S. 

 Geog. Expl. Surv. W. of 100th Mer., V, p. 624, pi. xviii, figs. 2, 2o.— Cope, 

 Check-list N. Amer. Batr. Rept., 1875, p. 36. 



Form stout; tail one-eighth of total length. Head slightly distinct, 

 large, depressed. Rostral plate acute; its anterior border elevated; 

 its upj)er surface concave. It is produced backward, separating the 

 prefrontals, not reaching the vertical. Frontals two pairs. Nasal con- 

 founded witli the first labial, a groove from tlie nostril to the suture of 

 the second labial. No loreal, its i)lace supplied by the postfroiital. 

 One preocular, two ])ostoculars. Scales smooth; anal and subcaudal 

 scutelhe divided. Teeth small, of equal lengths. Pupils round. 



Prefrontals triangular, not larger than preoculars. Postoculars of 

 equal size. Anterior border of vertical not angulated. Occipitals as 

 broad as long, truncate posteriorly. Superior labials seven, eye over 



' Proc. Acad. Nat. Sci. Phila., 1866, p. 126. Ficimia ornata Bocourt. Mission Scii-ntif. 

 de Mexique, p. 571, pi. xx v, fig. 10. 



