SHORE FISHES OF GALAPAGOS ISLANDS 405 



as described differs from X. laticlavius in having a greater depth and 

 in being of a uniform dark brown coloration. Our specimens show 

 clearly that there is no specific difference between the Galapagos, 

 Cocos and Revillagigedo specimens, that the types of the 2 species 

 X. laticlavius and X. clarionis are simply 2 extremes of variation 

 in form of the same species, and that the 2 extremes may occur at the 

 same locality. 



Description of a typical specimen. Length 355 mm.; head 3^; 

 depth about 2 ; D. VII, 26 ; A. Ill, 22 ; eye 3 in snout ; pectoral 4 

 in length ; ventral 7^- in length ; snout prominent, rounded ; profile 

 from snout to eye concave, bulging before eye, slightly concave from 

 eye to top of head where profile becomes prominently convex to front 

 of dorsal; greatest depth at middle of body; dorsal profile almost 

 evenly rounded, being but slightly more convex in front than behind ; 

 ventral profile with about same convexity as dorsal, but less convex in 

 front, outline here being about straight from chin to base of ventrals ; 

 lower jaw included ; least depth of caudal peduncle 3^- in length of 

 head, equal to its ventral side. 



Dorsal of almost uniform height except first 2 spines which are 

 smaller than the others ; anal highest in front where slightly higher 

 than dorsal, ending in front of end of soft dorsal ; first anal spine rudi- 

 mentary ; caudal fin large, upper and lower margins convex, truncate 

 posteriorly, slightly notched at middle ; teeth large, one series in each 

 jaw ; each tooth expanded terminally where it overlaps the one on the 

 outer side of it; distal margin of each oblique with inner or an- 

 terior angle highest, divided into 5 rounded lobes; caudal peduncle 

 with 3 large median plates on each side, each bearing a large hard 

 knife-like longitudinal ridge having the anterior angle elevated and 

 acute, each plate black ; in front of these numerous other dusky colored 

 plates, each conspicuous as a black spot, some bearing a very small 

 spine ; a groove in front of eye running forward and downward imme- 

 diately below nostrils, becoming obsolete in front of nostrils; all parts 

 covered with minute asperities ; lateral line high, closer to back pos- 

 teriorily than anteriorly. 



Color, plain dark gray with black spots on caudal peduncle. 



Variations. The depth in different specimens varies greatly, in 

 some being greater than half length while in others it is much less. 

 A few of the specimens present a very marked divergence from the 

 others in having the profile from snout to eye very deeply concave, 

 forming a prominent convex angle in front of the eye with that part of 

 the profile behind eye. One of these specimens is also very low for the 

 Proc. Wash. Acad. Sci., January, 1905. 



