COTTOIDS. 
165 
C E N T RIDER M I C H T H Y S HAMATUS. 
Fig. 50. 
Skin for the most part naked , on the top of the head and the back more or less verrucose; but the openings of 
the lateral line supported by spinous, scaly formations , and between the dorsal edge and the lateral line one longi- 
tudinal row ( in the males two or three) of spinous disks of bone or simple spines directed backwards — similar 
formations sometimes occur along the base of the anal fin — and also in the males scattered , spinous scales on 
the abdominal sides below the pectoral fins. Four preop ercular spines , all well-developed , the uppermost bent , and 
usually {in adult specimens ) branched {bicuspid). In the females only tivo occipital spines , each continued anteriorly 
into a ridge; but in the males there commonly appears , on the front part of these ridges as well, a protuberance 
or spine. On each side of the head a 3 fine, deciduous , dermal filaments, the largest of which has digitate divi- 
sions in the margin and is situated above the posterior part of the eye. The posterior part of the head and the 
body just behind the occiput somewhat elevated, and the profile of the head sloping steeply towards the snout. 
Length of the head from 28 to nearly 33 % of that of the body. Length of the upper jaw more than 12 % of 
that of the body or than 60 % of the base of the anal fin. Length of the lower jaw more than 16 % of that 
of the body. Length of the base of the second dorsal fin more than 28 % of that of the body. ' Length of the 
base of the anal fin less than 72 % of that of the base of the second dorsal. Least breadth of the interorbital space 
{at least in adult specimens) more than half the least depth of the tail. Anterior part of the lateral line straight 
or curved upwards. Urogenital papilla of the male long. Eggs somewhat smaller than those of the preceding 
species b . ■ Coloration brownish yellow on the back, with, dark-brown transverse bands, which are, however, usually 
broken up into irregular spots, on the head and the body — on the sides of the tail, below the lateral line, these 
spots are sometimes arranged in a longitudinal row — the ventral side a paler yellow / the pectoral fins thickly 
striped transversely with varying shades of dark-brown and yellow, as are also, though with fewer stripes, both 
the dorsal fins and the caudal fin, and sometimes the anal. The rest, of the last fin is of the same colour as 
the belly, like the ventral fins, which are, however, sometimes spotted. 
Fig. 50. Centridermiclithys hamat'us, 9) from Fairliaven (Spitzbergen), taken at a depth of from 20 to 25 fathoms, on a clayey bottom, on 
the 30th of August, 1872. Natural size. 
R. br. 6; D. 8 c j 1 9 — 21 d ; A. 14 e ; P. 17 /; V. >/ 3 ; C. 
.£ + (8)9 +«; L. lat. por. 35 — 45 g . 
Syn. (?) Cottus bicornis, Reinh., Dansk. Vid. Selsk. Math. Naturv. 
Afh., 8:de Deel, Overs., p. LXXV. 
a According to Esmark and Collett. 
6 In a gravid female 55 mm. in length, taken in Liebde Bay on the 3rd of September, 1868, and also in another 75 mm. in length, 
taken on the 30th of August, 1872, in Fairhaven (Spitzbergen), the eggs are about l 3 / 4 mm. in diameter. 
0 Sometimes 7, according to Collett; sometimes 9, according to Kroyer, Collett and Lutken. 
d Sometimes 17 or 18, according to Malmgren and Collett. 
e Sometimes 13, according to Collett; sometimes 15 or 16, according to LOtken, Collett and Kroyer. 
f From 17 to 19, according to Collett. 
'J The last number is given according to Malm. The first number given is taken from a female 63 mm. in length, from Spitzbergen — 
in this specimen the lateral line ends about half-way between the end of the base of the anal fin and the base of the caudal fin. 
