698 



SCANDINAVIAN FISHES. 



side of the angle of the clavicle. W'iieii the spinous 

 ray is erectefl, it is simultaneously twisted in a forward 

 and downward direction — the result ol the above- 

 mentioned obli(jue position of one of the two articular 

 surfaces on the scapulo-coracoid bone — and during this 

 twisting process the last-mentioned, pulley-shajjed knob 

 rubs against the wall of the clavicular groo\e — thus 

 producing the creaking noise — until this articular knob 

 is so tirmlj' wedged in the lower end of the groove that 

 the ray cannot be bent without being t^visted back at 

 the same time. Another consecjuence of tjie erection of 

 the spinous I'av is that the insertion of the tin, wliicli 

 previously occupied an oblique position, in a backward 

 and do\vnward direction, now becomes horizontal. The 

 other rays of the pectoral tins ;ire repeatedly branched, 

 tiie tirst being sometimes twice as long as the spinous 

 ray, the tirst (uppermost) three or four gradually in- 

 creasing in length, the lower ones from this point very 

 gradually decreasing in length down to the last two or 

 three, which grow rapidly shorter, one after another. 

 The last ray is not even half so long as the spinous ray. 

 The entire length of the fins, from the upper angle of 

 the insertion to the tip of the longest ray, is in our 

 males more, in our females less than "/s of the length 

 of the head". 



The ventral tins are of a broad oval shape. Tiieir 

 first ray is simple but short. They are inserted at about 

 tiie end of the first third of the body, so far l)ack that 

 the distance between the dorsal tin and the tip of the 

 snout measures only about 7.5 — 70 % (in young speci- 

 mens 80 %) of the distance between the ventral fins and 

 the same point. Their length is in the males more, in 

 the females less than '/^ of the length of the head''. 

 The pelvic bones are of a shafted spade- shape, with the 

 outer posterior margin forming an arc. They meet each 

 other partly in a fairly firm suture between the pos- 

 terior (extended) parts, partly in a ligamentous con- 

 nexion between the anterior ends. 



The lateral line follows a straight course along the 

 middle of the sides of the tail (sometimes a little higher, 

 sometimes lower), but in front it rises in a greatly elong- 

 ated arch up to the temjjoral region, and may often 

 be traced distinctly in a straight line across the cheek 

 below the eye, as shown in our figure. The slimy 



surface of the skin, as we have mentioned aliove, is 

 entireh' scaleless. 



The coloration seems to vary considerabh- according 

 to local circumstances. The ground-colour is above 

 olive-gi'een, below white. The back is always darker, 

 sometimes shading even into black. The sides are ir- 

 regularly spotted (mottled), in light specimens witli 

 large and distinct spots of the dark colour of the back 

 on the ground-colour of the belly, which grows lighter 

 and lighter below. The dorsal fin is of the same dark 

 colour as the back, olive-greenish or black. The other 

 fins in common repeat the coloration of the l)od\', the 

 l)ase bearing the colour of the back, the margin or outer 

 part that of the bell}'. Such was at least the a])pearance 

 of tiie large Sheatfish, a male, from which our figure 

 is taken. It reaehed Stockholm alive, and was kept alive 

 while the artist ])ainted it. But as its strength began 

 to fail, the lighter parts, esjjeciall}' of the pectoral, \en- 

 tral, and anal fins, became more and more suffused with 

 blood, and finally, when the fish was in a moribund 

 state, l)lood oozed in drops from the margins of these 

 fins. The maxillary barl)els are on the upper side of 

 the same colour as the l)ack, underneath paler or even 

 of the .same colour as the belh'. During life the outer 

 parts of the eyes were l;lackisli blue, the inner parts 

 lighter blue, with the iris yellow but punctated with 

 dark dots and set off by a sharply-defined, yellow inner 

 margin from the pupil, which was blaek. 



The length of the abdominal cavity measures in 

 voung Sheatfish about ',.,, in older ones about V4 of 

 that of the bod)'. The peritoneum is white. The oeso- 

 phagus is continued straight backwards by the large and 

 muscular stomach, tlie pointed or I'ounded bottom of 

 which lies almost above the middle of the length of tlie 

 pelvic bones. Rather far forward, at about the middle 

 of the stomach and on its under surface, the pyloric 

 part projects in a forward direction. This part is bounded 

 from the intestine by a more or less strong contraction, 

 and internally divided from the same by a valve". The 

 duodenum, which is without appendages, is of about 

 the same tiiickness as the pyloric part, runs first for- 

 ward nearly to the diaphragm, then bends upwards to 

 the right of the oesophagus, and curves backwards, de- 

 creasing in thickness and thus ])assing imjiei-ceptibly 



" In the former 72—81 %, in the latter .54—55 °. of the length of the head. 

 '' ,, V ,. 48—53 "., „ „ ,, .S4— 36 \ „ „ „ ., ., 



'■ In a male nearly 2 metres long the total length of the oesophagus and stomach is abont 35 cm., and the distance between the 

 pylorus and the bottom of the stomach about 1 dm. 



