154 THE VOYAGE OF H.M.S. CHALLENGER. 



series between the dorsal fin and the lateral line; crests of the dorsal scales simple, 

 triangular, spines directed backwards, without denticulation. The abdomen between the 

 vent and the roots of the ventral fins scaleless. The distance of the vent from the 

 isthmus nearly equal to that of the hind margin of the eye from the extremity of the 

 snout. Barbel minute. Ventral fin very small, scarcely in front of the pectoral, with 

 the outer ray produced into a filament, which does not reach the vent. Pectoral as long 

 as the postorbital portion of the head. Anterior branchial arch with twenty-two very 

 short styliform gill-rakers. 



Light yellowish (in spirits): vertical fins, ventral filament, interior of the mouth and 

 branchial cavity black. 



This species was discovered by Mr. John Murray during the cruise of the " Knight 

 Errant" in the Faroe Channel, at a depth of 555 fathoms (Station 4, August 10, 1880). 

 Four specimens were obtained ; the two larger are 1 4 and 1 5 inches long, and the two 

 smaller ones 8 and 10 inches. The latter, being the younger, differ from the former, as 

 usual, by a relatively somewhat larger eye and a somewhat shorter abdomen. 



Bathygadus. 



Bcdhyrjadus, Giinth., Ann. and Mag. Nat. Hist., 1878, vol. ii. p. 23. 



'^" Head short, thick. Snout not projecting beyond the mouth; jaws even in front. 



Mouth wide, anterior and lateral. Eye small. Teeth in both jaws villiform, in narrow 



bands, which occupy the whole length of the jaws. Barbels present or absent. The two 



dorsal fins are almost continuous, and the anterior rays of the second are not shortened, 



■^v; , but gradually diminish in length in the narrow posterior jjortion of the tail. Anal rays 



feeble. Bones of the head cavernous, soft, without prominent ridges. Scales small, 



, cycloid, deciduous. Three and a half gills only, there being no slit behind the fourth 



' arch; gill-lamina3 very short. The first branchial arch quite free, with numerous long, 



-, setiform gill-ralcers. 



Bathygadus cottoides (PI. XLII. fig. A). 



Bathygadus cottoides, Giinth., Ann. and Mag. Nat. Hist., 1878, vol. ii. p. 2.3. 



D. 8. P. 10. V. 8-9. 



The head is large, thick, and in the nuchal region of considerable depth. Nothing 

 can be said of its integuments, which are lost, leaving the bones and cavities bare. The 

 muciferous channels are of great width, formed of very thin bone. The eye is small, 

 situated anterior to the middle of the length of the head, about one-sixth of its length, one- 

 half of the length of the snout and of the width of the interorbital space. Snout broad. 



