8 



SCANDINAVIAN FISHES. 



longitudinal folds underneath, and starting from the 

 iuterniaxillary, forms with tlio under lip a distinct 

 corner at each side of the mouth. A broad flap hangs 

 on either side of the under lip. Tiiis formation of the 

 mouth gives it some resemblance to a swine's snout, 

 and is the origin of the name Berggalt (>: rock-boar/), Berg- 

 gylta, etc. The caAit\ of the mouth is narrow, and 

 li.is pahitnl curtains (tninsverse folds or reJa) above and 

 licl()\v which are opposite each other and seem intended 

 to prevent the escape of water oi- food through the 

 mouth in the net of breathing or swallowing. The 

 tongue is tiiin, nnd at the tip flat and attenuating. 

 \\'lien the mouth is open, the upper jaw projects con- 

 siderably, as the long nasal processes of the inter- 

 maxillary bones glide forwai-d on the ethmoidal and 

 frontal bones. In both jaAvs there is a row of small, 

 conical teeth, largest in front and gradually diminish- 

 iiii;- in size as they recede on either side. Within this 

 row in the anterior part of both jaws is a. row of 

 much smaller teeth which project very slightly or are 

 concealed by the gums. There are no other teeth in 

 the mouth itself, either on the tongue, the palatine, or 

 tiie vomer; l)ut in tlie ])harvnx there are two small 

 ii/)/ii')- pharyngeals (each composed of three bones), 

 wiiich articulate Avith the bottom of the skull, and one 

 ti-ilobiitc Joirer pharyngeal, all thi'ce densely set with 

 small, (jl)tuse, conical teeth. The e}es are circular, and 

 their diameter is from '/f, ^*' ','7 ''^ ^^^e length of the 

 head. They are placed fairly high, their inferior edge 

 being above a line drawn from the apex of the upper 

 jaw t(j the middle point of the tail. The nostrils are 

 small, and liave two distinct openings on each side, 

 tile antei'ior being jirolonged into ;i dermal canal with 

 widened month. The sides of tlie head are covei'ed 



than its length, and the posterior margin forms t\vo 

 corners and is continued by a flap of skin which runs 

 out into a fine point at the lower corner. The inter- 

 opercidum is also large and distinctly visible under the 

 preoperculum ; it has some scales on the posterior portion 

 in the top corner. There are 5 branchiostegal rays, and 

 the branchiostegal membranes are united 1)}' a thick in- 

 tegument which hangs quite free round the breast and 

 is attached to the isthnuis only by its front point. 



The body is oval and laterally compressed; it is 

 completely covered with large imbi-icate scales, which are 

 thin, have an entire edge and are not marked exteriorly 

 Avith any large streaks. The lateral line is generally 

 composed of from 42 to 44 comparatively small scales 

 pierced by a horizontal tube, a\'1uc1i ai'c not contiguous 

 but separated by the scales of the two nearest rows. 

 It is consequently not very distinct, and it I'uns parallel 

 with the curve of the back as far as the extremity of 

 the dorsal fin Avhere it makes the same downAvard curve 

 as the dorsal line. Above the lateral line there are 6 

 or 7 rows of scales and below it 13 or 14. The vent 

 is a little behind the middle point of the body. 



The dorsal tin commences just over the base of 

 the pectoral tin and ends in a sharph" rounded corner 

 just where the back slopes towards the tail. At first 

 its edge is slightly convex, then somewhat concave, 

 rising again at the l:)eginning of the soft-rayed portion. 

 Its anterior part generally consists of 19 or 20 spinous 

 rays between Avhich the membrane is serrated at its 

 edge and prolonged behind each ray except the last 

 into a long, lancet-shaped flap. In the posterior part 

 are 10 or 11 branched and articulated soft rays, the 

 first of whicli however is, as a rule, simple at the point, 

 while the last is divided to the ):)ase, apparently forming 



with scales, with the exception of the preoperculum ! two separate rays. In the anal fin there are 11 or 12 



itself, the edge of the ])reopercidum and the anteorbital I rays, the first three of which are short and spinous, 



region. It is true that in mature specimens the edge the others longer, soft and articulated. Behind each of 



of the preoperculum is not apparently denticulated, but '\ the first two spinous rays the fin membrane is serrated 



on taking away the skin one finds on the bone itself 

 tine serrations, which are also indicated by some narrow 

 strips of skin oi'iginating in llie middle of the edge. 

 In younger specimens the whole edge of the |ireoper- 

 cnlum is sometimes shari)ly and cleiirh' erenulated, a 

 i'act which has caused such specimens to be regarded 

 as a disthict species, under the name Cirnilaltnis niiilfi- 



as in the dorsal fin. In the same way the first soft 

 ra,j of the anal fin is often simple, while the last is 

 always deeply cleft. The fin is rounded at its extremity 

 like the dorsal fin. In length it is about V'- of the 

 total lengtlr. Tlie ])ectoral fins are thin, with distinct 

 rays and rounded point; they consist of 15 rays, the 

 first of which is short and, like the next rav, undivided 



fJoifafiift. 



Tiie operculum is Imge, its depth is greater ' at tlie point; the others ai'c branched and thick. The 



■" The relative leugtli of tlie biise of tlie iiii:il tin tlimiiiislios with ago. In G measured specimens it was on an average 13.7 % of 

 the total length; the niiniiinini was 12.4 %, tlie niiixiiniuii 14.5 %. 



