468 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



spine is broken at its extreme tip) ; the third ray is longer than in 

 C. sexradiaius, being contained 1.21 times in the length of head. The 

 base of the first dorsal fin is contained 1.2 times in the interdorsal 

 space, or 1.4 times in the postorbital length of head. The second 

 dorsal fin is rather low anteriorly, the first ray being contained 6.3 

 times in the postorbital. The origin of the anal is anterior to the 

 vertical from the middle of the interdorsal space. Pectoral fin, 1.6 

 in head; outer ventral ray, 1.75;. second ventral ray, 2.85, reaching 

 a little beyond the origin of the anal. 



The ground color is a little lighter than in sexradiatus or notatus, 

 and much lighter than in macutatus or velifer. The dark shade of 

 the belly extends from the anus to the isthmus and on the sides to 

 above the ventrals. The blackish brown spot above the pectoral 

 extends upward to the lateral line and covers six scale rows. A 

 dusky region, of squarish outline, extends from the first dorsal for- 

 ward to the occiput, and downward on each side to the origin of 

 the lateral line; it bounds the upper anterior margin of the light 

 area about the suprapectoral spot. A dusky area which extends 

 downward and backward to the lateral line is separated from the 

 spot by an interval shorter than in notatus (being but two-fifths as 

 long as the head) ; a similar but smaller, and only faintly ocellated 

 saddle, is separated from the first by an interval half as long as the 

 head. A black spot, located on the sides of the branchiostegal mem- 

 branes, is separated from the free edge by a narrow whitish line. 

 The opercle is dusky, with a small blackish spot near its angle. 

 The first dorsal fin is dusky black only on the spine and on the 

 distal portion of the anterior soft rays; it is whitish elsewhere. 

 The second dorsal fin is light; the anal is dark anteriorly, especially 

 toward the tips of the rays. The ventral fin is chiefly dusky, be- 

 coming darker distally, blackish near its base, and whitish on the 

 filament of the outer ray. The pectoral rays, with the exception of 

 the uppermost two, are light. 



The differences between C. triocellatus and notatus may be summed 

 up as follows: the body is more strongly compressed; the snout is 

 much longer, narrower, and more acute; the dorsoterminal plate 

 is much longer; the anus is more posterior in position; the spinules 

 on the scales of the body are longer; other differences exist in the 

 squamation of the head arid in the coloration. C. triocellatus dif- 

 fers from sexradiatus in several characters: the body is more com- 

 pressed; the snout is longer, narrower, more acute; the anus is 

 located farther forward; the ventral fossa is shorter; the pectoral 

 and ventral rays are more numerous;. the coloration is more varie- 

 gated; additional differences in squamation have been noted in the 

 description. 



