1878.] 701 
[Cope. 
length M. .166; of the head, .035 ; to origin of ventral fin, .063 ; of anal 
fin .090 ; of second dorsal fin, .096 ; of caudal fin, .141. 
Besides the generic characters mentioned, this species differs from the 
Protistius semotilus of the same region, in the larger number of soft rays, the 
smaller eye, narrower interorbital space, etc. The lateral line is better de- 
fined in this species, but is not continued beyond the anal fin; a few iso- 
lated tubes occur on scales on other parts of the sides. 
The color of the Gastropterus archeus is silvery, darker shaded on the 
upper surfaces, and without spots on the body or fins. 
Two specimens ; coll. of 1874; obtained by Prof. Orton, at Arequipa on 
the Pacific slope at an elevation of '7500 feet. 
PUBLISHED JUNE 26, 1878. 
