CdTTdlllS. 



165 



CENTRIDERMICHTHYS HAMATUS. 



Fig. 50. 



Skill for tlie most part naked, on flic lop of tin' licod am/ tlic, hack more or less rerrucose; hut the openings of 

 the lateral line sapiiorted hij spiiioas, se<dy formation.'', and hettveen the dors(d edf/e and the lateral line one longi- 

 tudinal roir (in the males ta-n or three) of spinous disks of hone or simple spines directed hackirards — simiJar 

 formations sometimes occur along the hase of the anal fin — and also in the males scattered, spinous scales on 

 the ahdominal sides helow the pectoral fns. Four preopercular spines, all well-developed, the uppermost hent, and 

 usualli/ {in. adult specimens) branched {hicuspid). In the females onlg tivo occipital spines, each, continued anteriorly 

 into a ridge; hat in the males there commonlg appears, on the front 2^(frt of these ridges as ivell, a protuherance 

 or spine. On each side of the head" 3 fine, deciduous, dermal filaments, the largest of which has digitate divi- 

 sions in the margin and is situ(ded ahore the posterior part of tJte ege. The posterior jxtrt of the head and the 

 hodij just hehind the occiput somewhat elevated, and the profile of the head sloping steeply tou-ards the snout. 

 Length of the head from ,28 to nearly S3 % of that of the hody. Length of the upper jan- more than 12 % of 

 that of the body or than 6'() % of the hase of the anal fin. LjCngth of the lower jaw more than 10 % of that 

 of the hody. Length of the hase of the second dorsal fin more than 28 % of that of the hody. Length of the 

 hase of the anal fin less than 72 % of that of the base of the second dorscd. Least hreadth of the iidcrorhital space 

 (at least in adult specimens) more than half the least depth of the tail. Anterior part of the lateral line straight 

 or curved upu-ards. Urogenital papilla of the male long. Eggs sometchat smaller than those of the jrreceding 

 species'". Coloration brownish yelloiv on the hack. with, dark-hroivn transverse hands, which are, hoivever, usually 

 broken, up info irregular .spots, on the head and the body — on the sides of the fail, helou- 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 u-ith 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. Centride.rmiclitlnjs hamatu.s, $, from Fairliaven (Spitzbergen), taken at a dcptli of from 20 to 25 fatlioras, on n clayey bottom, on 



the .30th of August, 1872. Natural size. 



R. br. 0; Z). S'jlO — 21''; A. U''; P. 17/ 

 ^ + (8)0 +.r; L. lat. por. ?,b — 45''. 



V. 



c. 



Syn. (?) Cottus bicornh, ReiNH., Dansk. Vid. Selsk. Math. Natiirv. 

 .Afh., 8:de Deel, Overs., p. LXXV. 



" According to EsM.\nK and Collett. 



'' 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, 

 (aken on the .30th of August, 1872, in Fairhaven (Spitzbergen), the eggs are about IV4 mm. in diameter. 



" Sometimes 7, according to Collett; sometimes 9, according to Kroyer, Collett and Litkex. 



'' Sometimes 17 or 18, according to Malmgren and Collett. 



■■ Sometimes 1.-5, according to Collett; sometimes 15 or IG, according to LOtken, Collett and Khoyer. 



■' From 17 to 10. according to Collett. 



!» The last number is given according to Malm. The tirst 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. 



