424 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
projecting spines or ridges. The occipital depression is very shallow, the occipital 
ridges depressed, scarcely noticeable, ending in depressed spines which are made 
out with difficulty. 
Nasal spines undeveloped, the nasal bone small, posteriorly pointed, but not fur- 
nished with a projecting spine. Upper preopercular spine strongly compressed, 
curved upward, not reaching opercular margin, its length equaling diameter of eye. 
No spine at its base in front, as in A. bathybius. Below it are two short, strong 
spines directed downward and backward, and one more slender downward and 
forward. Opercle with a longitudinal rib ending in a short spinous point. A short 
spine on angie of opercle, and one below it on interopercle. Mucous canals every- 
where greatly enlarged, giving a spongy texture to the entire head; series of very 
conspicuous pores on the preopercle, the mandible, and below suborbital chain. 
Head 23 in length; depth 5. Dorsal vi1-13; anal 10 or 11; pectoral 17 or 18; 
ventral I, 3. Lateral line with 17 pores. 
Mouth broad, oblique, maxillary reaching middle of pupil, 24 in head. Mandible 
slightly protruding. Minute teeth in upper jaw anteriorly in two rather distinct 
rows, laterally in narrow bands. Teeth on vomer, none on the palatines. Eye 
longer than snout, 33 to 4 in head. Interorbital width one-half diameter of orbit. 
Gill-membranes widely joined, with a wide, free posterior edge. No slit or pore 
behind last gill. Body smooth, without plates, granulations, or filaments. No 
plates developed in connection with the lateral line. Pores of lateral line in a double 
series; the two closely approximated, those of the lower series much the largest. 
Longest rays of second dorsal half length of head, twice the longest dorsal spine. 
Pectoral reaching front of anal or slightly beyond. Ventrals short, not nearly 
reaching vent. Upper parts very light-brownish, the belly and sides below lateral 
lines dark brown. Fins blackish. Mouth and gill-cavity dark. 
Three specimens, 49 to 55 mm. long, from station 3329, north of Unalaska Island; 
depth 399 fathoms. 5 
66. Gymnacanthus pistilliger (Pallas). 
We agree entirely with Dr. Bean and Mr. Dresel (Proc. U. 8. Nat. Mus. 1884, 251) in 
considering the North Pacific species, G. pistilliger, distinct from the North Atlantic 
form, G. tricuspis. We have not had an opportunity to make direct comparison 
between the two, but find the following differences on comparing our specimens with 
the current descriptions of G. tricuspis. G. pistilliger has a different fin formula, 
the spines and rays of dorsal and anal fins being fewer in number. This is shown 
by the following table, based on an examination of 40 specimens: 
] Spinous dorsal. Soft dorsal. Anal. | 
bere : 
ayes esses: Ix DG eee 0 ene al es ae ers mer eri || 
Specimens ... 10 30 1 17 21 1 2 28 10 
The normal formula may therefore be given: Dorsal 1x or x-13 to 15; anal 15 to 17. 
The type of G. pistilliger is said to have dorsal 1x-13; anal 16; and its synonyms, 
G. ventralis Cuvier & Valenciennes and G. intermedius Temminck & Schlegel, have 
respectively dorsal 1x-13, anal 17, and dorsal 1x-13, anal 14. 
In G. tricuspis, the formula is dorsal XI or x11 (rarely x)-15 to 17; anal 16 to 19. 
The dorsal fins are more widely separated in G. pistilliger, where the interspace is 
equal to half or more than half the diameter of the pupil. 
The vertebre are fewer in number, 12+24, instead of 12+-28. 
In G. pistilliger an obtuse prominence above the hinder margin of orbit bears in 
young individuals a slender cirrus, which frequently disappears in adults. Behind 
the eye a continuous occipital ridge bears three smaller bony prominences, the first 
