510 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 
the lower half of the nasal fossa, and the region below the orbit, 
extending backward to-the preopercular ridge, are reduced in size, 
but usually bear divergent ridges; the five series of scales between 
the occipital ridges converge backward toward the median occipital 
scute, which is variously armed by a single median keel or by 
several divergent ridges; a somewhat similar scute is located at the 
origin of the lateral line. The scales between the occipital and post- 
orbital ridges are in about five series, and bear several carinae; 
those scales forming the median series are markedly enlarged, those 
in the next series below the median are scarcely reduced, those in 
the first series above the median are small, those in the two or three 
other series are reduced in size. In C. japonicus the scales of the 
head are quite different; they are smaller, as a rule, and even in 
specimens considerably larger than any known of C. commutabilis 
mostly bear only a single spinous crest, except on the scaly ridges 
ee 
Fig. 29.—CoELORHYNCHUS COMMUTABILIS. AFTER RADCLIFFE (‘‘ COELORHYNCHUS 
COMMUTABILIS, FORM ALPHA’”’). = 
and in the median series between the occipital and postorbital ridges. 
The underside of the head in both species is constantly covered by 
small scales. 
Pyloric caeca, 20 in one specimen, 28 in another (50 were counted 
in a specimen of C. japonicus). 
The height of the second dorsal spine in contained 2.1 (1.85 to 2.1) 
times in length of head; its length when laid out on the head from 
the opercular angle extends forward to the front of pupil (in para- 
types varying forward and backward from that point a distance 
almost as great as the diameter of the pupil). The length of the 
first dorsal base is contained 1.63 (1.35 to 1.75) times in the interval 
between the dorsals, and 2.1 (1.7 to 2.1) times in the postorbital 
length of head. The outer ventral ray, ending in a slender filament, 
is contained 2.65 (2.1 to 3.0).times in head; the second ventral ray, 3.7 
to 4.35 times, not reaching to the anus. 
Color in alcohol grayish brown, of varying shade, becoming 
lighter below; darker and less silvery than in C. radcliffei, We 
brownish than in (. smithi. The fins are blackish, varying to light 
