fc 



the Herring-king. 179 



of the ventral fins were present — namely, on each side an 

 anterior (or outer) ray, about 7 millim. long, but broken, and 

 therefore, in reality, longer, comparatively slender, strongly 

 spinous along its anterior margin, and behind this five shorter 

 and finer ray-rudiments. In all the other Vaagmasrs ex- 

 amined these rudiments of ventral fins were very indistinct or 

 had even completely disappeared, except in one (1*505 metre), 

 in which there were two basal portions of the anterior rays of 

 the ventral fins, about 20 millim. long and 3 millim. broad, 

 subprismatic, flat behind, with a rounded angle in front ; and it 

 was clear that they had been 30 or perhaps 50 millim. long. 

 Exceptionally, at any rate, this first ray in each ventral fin 

 may therefore exist in the fully developed state, as in liega- 

 lecus {Gymnetrus) , in adult Vaagmsers ; and we cannot abso- 

 lutely place the absence of this fin in the adult Vaagmser as a 

 character of this genus in contradistinction to its allies. 

 From what I have seen in young Mediterranean Trachypterij 

 I have been led to think that the loss or casting of the nuchal 

 and ventral fins was rather a shedding prepared by nature 

 than the consequence of an accidental fracture ; but I admit 

 that further investigations upon this point are to be desired. 



The measurements made of the individuals before me and 

 their comparison have shown (as will appear more clearly 

 from a table of numbers given at p. 204 of my detailed me- 

 moir) no small variation in the proportions of the parts of the 

 body and in other analogous characters. I had hoped to be 

 able to show definitely that these variations to a great extent 

 corresponded to differences of age, so that in the height of the 

 body, of the dorsal fin, and of the caudal fin, in the higher or 

 lower position of the lateral line,- in the size of the head and 

 eye, in the abruptness of the profile, &c. there would be a dimi- 

 nution or an increase in parallelism with the age and the size 

 of the body. But this hope became fainter and fainter the 

 more specimens I examined. In part, however, the apparent 

 vacillation and irregularity in these chai*acters may be ex- 

 plained by the circumstance that these delicate fishes are con- 

 tractile, and therefore may change their form considerably, 

 according as they are hardened by placing them in salt or in 

 alcohol, or preserved in a more flaccid condition. To get over 

 the difficulties which are thus produced is, so to speak, impos- 

 sible ; and I must therefore confine myself to indicating within 

 what limits I have found these characters variable, and how 

 far they may be considered to stand in any connexion with 



differences of age. 



The length of the head and body together (as far as the 

 anus), in proportion to the total length, varies between 1 : 176 



