THE REPTILES OF THE GALAPAGOS ISLANDS. 85 



of 6r. ocellatus, the scales under the fourth toe are smaller 

 toward the base ; in our species they are about equal in 

 size. 



Hob. Wreck Bay, Chatham Island. 

 OEOPHIS BISERIALIS. 



Herpetodryas biserialis Gthr.,-1860, Pr. Zool. Soc. 



Lond., 97. 

 Dromicus Chamissonis Pet. t 1869, M. B. Berl. Akad., 



719. 

 D. Chamissonis var. biserialis Gthr., 1870, Zool. 



Eec.,vi, 1869, 115. 

 D. Chamissonis var. dorsalis and var. Hdbelii Steind., 



1876, Schl. u. Eid. der Galap.-Inseln, p. 6, pi. 1. 

 Opheomorphus Chamissonis Cope, 1889, Pr. U. S. 



Mus., 147. 



There is a single specimen of this snake in the collection 

 from Hood Island. It is intermediate between Giinther's 

 species biserialis and Steindachner's variety Habelii. Struc- 

 turally it agrees with the type described by Giinther, but 

 it has no spots on the back. The dorsal band is continuous, 

 though fainter and indistinctly margined behind the middle 

 of the length. The type from which the species was origi- 

 nally described was said to be from Charles Island. The 

 present specimen from another locality possesses the 

 squamation of one of the so-called varieties and the color- 

 ation of the other. This seems to me to indicate the exist- 

 ence of but one variety, of which the spotted forms and 

 those with three postorbitals are individual variations. 

 There is nothing in the published evidence to show that 

 the striped form, the spotted form, that with two postor- 

 bitals, and that with three do not occur amongst the indi- 

 viduals of any of the localities inhabited by this snake. 



