228 MR. A. W. E. O'SHAUGHNESSY ON [Feb. 1, 



The specimens were collected at three distinct stations : — viz. 

 Canelos, Pallatanga, and Sarayacu. 



Tejid.e. 



1. Centropyx dorsai.is, Giinther. 



Monoplocus dorsalis, Giinther, P. Z. S. 1859, p. 404. 



Centropyx peMceps, Cope, Pr. Ac. Phil. 1868, p. 98. 



? Centropxjx altamazonicus, Cope, J. Ac. Phil. (n. s.) viii. 1876, 

 p. 162. 



Two specimens, the largest measuring about 11| inches long, 

 from Canelos. Another good-sized specimen, from the Peruvian 

 Amazons, is also in the British Museum. By its keeled praeanal 

 scutes this species would be the C. altamazonicus. Cope, rather than 

 his C. pelviceps ; but I am inclined to think that the very small 

 specimen on which the former is founded will prove identical with 

 the latter. If so, both must be referred to the species described by 

 Dr. Giinther, also on a small type specimen, in which, after re- 

 newed examination, I do not find that the distinctions relied on by 

 Prof Cope when describing C. pelviceps hold good, as I count 

 fourteen longitudinal series of ventrals in the middle of the body, 

 and can also distinguish femoral pores. The largest specimen from 

 Canelos has the sixteen ventral series characteristic of 0. altama- 

 zonicus, though that species shows them already in a young speci- 

 men. I may add that Dr. Giinther's type possesses the anal spurs 

 of this genus. 



2. Neusticurus ecpleopus. 



Neusticurus ecpleopus, Cope, J.Ac. Phil. 1876, p. 161 ; O'Shaugh. 

 Ann. N. H. ser. .5, vol. iv. p. 295 (1879). 

 Pailatanga. 



Cercosaurid^. 



Emminia olivacea of Gray is a Cercosaura, as was rightly surmised 

 by Dr. Peters in 1863; moreover it is so closely related to Cereo- 

 saura ocellata, Wagler, that nothing but the conspicuous lateral 

 ocelli and the three additional femoral pores of that species separate 

 them. With regard to the prseanal scutes, I may mention that 

 another specimen from Para, which, some time since, I had occasion 

 to add to the named series in the British Museum, has the two large 

 plates figured by Peters as belonging to Wagler's species, instead of 

 the four smaller marginal plates of Gray's type ; but on this ground 

 alone I should not venture to separate it from C. olivacea, with 

 which it agrees exactly in every detail. It is perhaps superfluous 

 to state that no foundation for the peculiar position assigned to the 

 nostril by Dr. Gray is afforded by the specimen. 



A similar variability in the arrangement of the praeanal scutes, 

 associated with an irregularity in the plates of the muzzle, is shown 

 in a series of four specimens, which, however, cannot be specifically 

 distinct, and are doubtless referable to the species described by Prof. 



