CUKAT I'UKKHIJ IJEAIJU. 



')41 



the least depth of the Ixidy (tail) varies between ^'/a % 

 (in youth) niul I % (in old s])ocinieiis) of the length 

 of the body or between 27 ;uid ?i\ % of the length 

 of the lower jaw. 



In full-grown specimens tlu- lieiid p.'irt.'ikcs of the 

 general coni])ression of the body. Above it is fl;it or 

 slightly convex, and its Hat sides, the cheeks, are al- 

 most parallel to each other, 'flir length of the head 

 varies with age" between about 22 and 23 % of that 

 of the body. The eyes arc rather oblong and fairly 

 large, the longitudinal diameter of the orI)its varying 

 with age between about 6"„ and 5 % of the length of 

 the body or 30 and 22 % of that of the head. They 

 are set in the second third of the head, though the 

 length of the snout varies between about 2S and 33 % 

 of that of the liead, and the postorliital length of the 

 Iicad between aliout 42 and .50 % of the total length 

 thereof. The nostrils are set in the last third of the 

 snout, on about a level with the centre of the eye, the 

 distance between them being about the same as that 

 between the posterior one and the margin of the orbit. 

 The anterior nostril, which is a small, round (opening, 

 is marked liv a lobate elevation of the hind superior 

 part of tlie margin; the posterior is t^vice as large and 

 oblong, without any elevation of the margin. Tlie tip 

 of the snout jjrojeets beyond the margin of the upper 

 jaw, and the latter in its turn beyond the tip of the 

 lower jaw. The whole snout is soft and of a loose 

 structure, this being due to the extensive development , 

 within it of the muciferous ducts of the system of the j 

 lateral line. The opercular apparatus is most like that 

 of the Hake, with triangular, almost forked operculum. | 

 The suboperculum is thin l)ut broad, and pointed at 

 the top (l)ehind): it lies under and tills the deep inci- 

 sion in the hind posterior margin of the operculum, 

 while the iinier part of its truncate, anterior (lower) end 

 touches the interoperculum, which is thicker but nar- | 

 rower. Thus the margin of the entire opercular appa- ! 

 ratus is somewhat incised at this point. The preoper- 

 culuni, with its broad margin (to receive the muciferous 

 duct) is rectangular lint rounded at tlie angle. The 

 branchiostegal membranes are united into a collar under- 

 neath, but this collar terminates posteriorly almost ver- 

 tically below the centre of the eye. The jaws resemble 

 those of the Cod. The maxillary bones extend back 

 to the perpendicular from the hind margin of the pupil, 



the intermaxillaries being a little shorter and reaching 

 oidy to the per])endicular from the interior margin of 

 the jtupil. The distance between the tip of the snout 

 anil the hind extremity of the maxillary liones is greater 

 than the postorbital length of the head and more than 

 h.ilf the totrd length of the head, but less than the 

 length of the lower jaw, which varies between 60 and 

 537g % of the length of the head or between 33 and 

 28 % of that of tlie ba.se of the anal fin. Tiie post- 

 orbital length of the head is thus always less than the 

 length of the lower jaw, but increases with age even 

 in this relation, from about 70 to 90 or 91 %. The 

 length of the barbi-l under the chin is somewhat less 

 than that of the eye. The teeth are most like those 

 of the Burbot, being small ;ind of uniform size, but 

 set in a dense card in the lower jaw and on the inter- 

 maxillary bones and in a curve, somewhat pointed in 

 front, on the head of the vomer. Tlie palatal folds 

 behind the jaw-bones arc narrow Imt distinct, at least 

 in the lower jaw. The tongue is flat and broad, with 

 a narrow, free tip and margin. The gill-rakers, 14 or 

 15 in number on the first branchial arch, are well- 

 developed, but not of any great length. The phar- 

 yngeal teeth resemble the jaw-teeth. 



The first dorsal tin begins at a distance from the 

 tip of the snout that varies with age between ab<nit 

 25 and about 29 % of the length of the body, and it 

 terminates close to, but quite distinct from the begin- 

 ning of the second dorsal fin. When erected it has the 

 form of an almost right-angled triangle with the riglit 

 angle at tlie hind corner and with the shortest side 

 (the base) measuring about 6 or 7 % of the length of 

 the bodv. As a rule the first three ra)'s are simple, 

 and the third rav is elongated into a filament abput 

 twice as long as the fourth ray, which, like the others, 

 is branched. The first ray is about half as long as the 

 second, which is somewhat shorter than the fourth. 

 The variations in this respect are, however, considerable, 

 and the elongated rav sometimes projects only slightly 

 above the others, its length varying, even in adult spe- 

 cimens, between about 10 and 17 % of that of the body. 

 The second dorsal fin begins at a distance fi'om the tip 

 of the snout of 32 — 36 % of the length of the body, 

 and its base, taking into account the individual varia- 

 tions, measures lietween 51 and 53 % of this length. 

 Its height is fairly uniform, but greatest (9 or 10 % 



" Here and in Uic following relations the changes of growth are given as we have found Ihein ia specimens between 18 and 57 cm. long. 



