PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 357 
isthmus. The slit behind the fourth gill is a little more than half as 
long as the pupil. The gill-rakers on the anterior arch are quite rudi- 
mentary, their length being rather less than their width; there are 8 
below the angle. ; 
The distance of the spinous dorsal from the tip of the snout equals that 
of the pectoral from the same point and is contained 44 times in the 
standard body length; the base of this fin is twice as long as the long- 
est ray of the soft dorsal. The length of the first spine equals that of 
the first ray of the soft dorsal and is contained 34 times in that of the 
head. The fourth spine is the longest, its length being contained 24 
times in that of the head. The last spine is very little more than 4 as 
long as the first. The first line is serrated along the lower third of 
its anterior edge, and all the following spines except the last are simi- 
larly armed along the anterior edge of their exserted tips. Even the 
first ray of the second dorsal is thickly set with minute spines. 
The length of the base of the soft dorsal is contained 2! times in 
the standard body length (or unit of length). Its first ray equals in 
length the longest anal ray; it is also as long as the first spine and as 
the distance from the snout to the orbit. The fourth, fifth, sixth, and 
seventh rays are the longest and about equal in length; they are twice 
as long as the last ray and one-fifth as long as the soft dorsal base. 
The membrane behind the last dorsal spine extends to the base of the 
first soft ray. The origin of the anal fin is vertically beneath the base 
of the second soft ray. The distance of the anal origin from the snout 
is less than the length of the anal base. The length of the first anal 
ray equals the least height of the tail and is slightly more than 4 that 
of the fifth to the eighth, which are the longest. The last ray is $ as 
long as the orbit. The vent is nearly midway between the origin of the 
ventrals and that of the anal. 
The caudal is distinctly emarginate when fully expanded. The length 
of the middle rays is contained 9 times, and that of the external rays 
745 times in the unit of length. 
The structure of the pectoral is similar to that in 7. pingelii, but the 
longest of the exserted lower rays extends considerably farther back 
than the upper portion of the fin. The origin of the pectoral is directly 
under that of the spinous dorsal. The length of the longest exserted 
ray (11th) is contained 45 times in the standard body length. Five of 
the lower pectoral rays are moditied. The tenth pectoral ray, which is 
the longest of the non-exserted portion, is only about 3 as long as the 
eleventh and extends to near the end of the spinous dorsal. . 
The ventral is situated farther in advance than in 7. pingelii, and 
does not quite reach to the vent when extended. Its length is con- 
tained nearly 12 times in the unit of length. 
Radial formula.—Br. V1; D. XI, 29; A. 29; C. 11 (developed); P. 
PED se V2 1,3); Lat. 50. 
Colors. —There are traces of the same half bars which ornament the 
