955 



of". The Ic.'ist depth of the Ixxly (of the tnil) mca- 

 siiiTS on nil aveiMg-i' (V ., — fi' .^ %' nf the siiid Icnii'tli. 

 Ac'cordiiii;' to the nu'thud of measuring the leiigtli of 

 the bod\- eiiiiilo\ed .•ih()\(', in the case of tlic (iwyniads, 

 i. e. from tiie artieui;ir lumbs of the in:ixill:iries to the 

 end of the middle caudal rays, the least depth of the 

 hodv varies between 8 and 7 % of its length. The 

 \ariatious in our specimens from BohusliVn are such 

 that the averages regularly decrease from 8"1 % to 7"3 % 

 as the length of the body increases from 1() to 37 cm. 

 The body as a whole is of the most beautiful fusiform 

 shape, the dorsal and ventral contours forming regular 

 and similar curves; but the lateral compression is so 

 marked that the greatest thickness, which, as we Ikiac 

 iiu'iilioncd, lies nearer to the back, measures, in the line 

 of the greatest depth, about half — in young specimens 

 and after the spawning about ' ^ — of the latter. 



The length of the head varies between 2"2'/o and 

 19', "</ of that of the body''. It is of the well-known, 

 three-sided, pAramidal sliajie that we have already seen 

 in the Flying-fishes, but with narrower upper surface 

 and w'ith the snout constricted above, in front of the 

 eyes. The most characteristic points are the prominent 

 tip of the lower jaw and the coat of adipose membrane 

 concealing a great portion of the eyes and extending 

 both over the sides of the snout and the upper part 

 of the slioulder-girdle. This membrane forms two folds 

 in front, one composing the anterior limit of the 

 orbit, and another the anterior eyelid, which passes 

 above without a break into the posterior, growing 

 narrower like the latter, but is somewhat broader be- 

 low, Iving in a fold outside the lower, pointed corner 

 of the jiosterior eyelid, whicli gradually passes behind 

 and below into the adipose membrane of the opercular 

 apparatus and the cheeks (the suborbital ring). In this 

 latter membi-ane, which is continuous both with the 

 covering of the sides of the snout (the preorbital bones) 

 and with the skin of the forehead and occiput, we find 

 an abundance of the ordinary ramifications of the lateral 

 line, which also occur on the shoulders, though every- 

 where less developed than we shall find them in the 

 Shads. The top of the head, from the nostrils right 



to the occipital crest, as far as the frontal bones extend, 

 is ci)iu'>ed (in each side b\- a wcli-niarkcd lateral ridge, 

 bounding a depressed, lanceolate area, dotted with mu- 

 ciferous pores, the ti]) of the area lying at the occipital 

 crest itself. But at the middle of tiiis area runs an 

 elevation, in front terete or even mesially depressed, 

 behind sharper, which is formed anteriorly b^- the above- 

 mentioned ridge on the ethmoidal cartilage, and dis- 

 appears posteriorly, behind tlu; interorbital space. The 

 eves are round, or slightlv longer than high, l>ut tlic 

 part free of the eyelids is elliptical, with the upper and 

 lower ends pointed. They are rather large, their longi- 

 tudinal diameter varying on an a\ crage between '/,, and 

 ' . of the length of the head, and being about equal 

 in adult specimens to the length of the snout from the 

 middle of its tip to the anterior corner of the eye, but 

 measuring only about half the ];ostorbital length of the 

 head. Thev' are set so high that their upjier nnirgin 

 approaches close to the frontal plane. The nostrils lie 

 on a level with the u|:)]ier margin of the puj)il and 

 about half as far from the anterior corner of the eye 

 as from the middle of the tip of the snout. The an- 

 terior nostril of each pair is round and distinct, though 

 comparatively small; the posterior more crack-like and 

 usually overhung by the adipose membrane belonging 

 to the sides of the snout. The two pairs are separated 

 by a distance measuring on an average about ',,, of 

 the breadtli of the snout at the articulations of the 

 maxillaries. The sharp tip of the snout is formed by 

 the thin-lipped interraaxillaries, which strongly remind 

 us, lioth in position and form, of those of the ^ endace. 

 They are fiat but somewhat arched, triangular, with 

 the posterior (outer) corner elongated to a point and 

 armed on the inner surface of the inferior margin with 

 a row of about 6 pointed, incurved (recurved) teeth. 

 The}' are without nasal processes ^ — the tip of the snout 

 being consequently not protrusile — and their anterior 

 lower corners are rounded to such a degree that they 

 are distinctly parted from each other at the middle of 

 the tip of the snout. But the sinus thus caused is filled 

 ])y the labial skin, the tij) of the snout being thus en- 

 tire and truncate, without indentation or groove. In 



" 111 the largest Herrings we often find retrogressions to Hie eliaracters of viKilli. In a full feniale, widi tlie lengtli of tlie liody 

 measuring 42 cm. and with eggs O'S — 1 mm. in diameter, taken in Febniarv, ISH". oif Helso (Northern BoluislaD). tlie greatest depth is 

 only 16-1 % of the said length. 



' Varying, according to Lilljehobg's uieasurements. between 5 and 7 %. 



' According to our ordinary method of measurement. 



