REPORT ON THE PELAGIC FJSHES. " 9 



(?) Lichia glauca, L., young (PI. 1. fig. G). 



The fish believed to Ijc tlie young of tliis species was obtained with the surface-net 

 on April 13, 1876, oii" the west coast of Africa, in kt. 10" 55' N., long. 17°4G' W., and is 

 only 10 mm. long. 



The accompanying figure will give u sutticieut idea of the general form of its body, 

 which is scaleless and of a silveiy colour. The spinous dorsal only is marked with a very 

 conspicuous deep black blotch. The proeoperculum is armed with a long spine at the 

 angle, and with several smaller ones besides, which are much more conspicuous on the 

 lower limb than on the posterior. Formula of the fins : D. o'V- A. /o. The fin-spines 

 are strong ; those of the dorsal as high as, and continuous with, the rays ; the third and 

 fourth of these spines are the longest. Caudal slightly emarginate. 



It was not without some hesitation that I ventured to refer this single young 

 specimen to Lichia glauca, without being able to prove the correctness of this view by 

 intermediate stages. However, 1 know of no other fish of this part of the Atlantic except 

 Tracliynotus goreensis { = Trachynotus myrias) with which it might be associated; the 

 general form of the head and body, and especially the numbers of the fin-rays, point 

 rather to Lichia glauca than to Trachynotus, whilst the fins, in the form of which our 

 young fish so conspicuously differs from that of matured fish, are just those organs which 

 we should expect to be modified w^ith age.^ 



Coryphaina, Artedi. 



The young stages of Coryphaiiia have been known for some time (see, for instance, 

 Fische der Siidsee, p. 146), but we owe to Dr. Llitken" our acquaintance with the means 

 of discriminating between the young of Coryphiena hippurus and Coryphwna equisctis 

 {loc. cit., p. 489). Yet, even with the help of the excellent figures which he has given 

 of the young of both species {loc. cit., pi. iii. figs. 'J-13) the specific determination is 

 often \evy difficult and uncertain, especially of individuals less than 1^ inches long. Of 

 the three sj)ecimens collected by the Challenger I refer two to Corypihwna hippurus, 

 viz., one of 1^ inches obtained in the North Atlantic on April 28, 1876, and one 

 I inch long from the vicinity of the Low Archipelago, September 16, 1875; and the 

 third to Coryphiena equisctis ; it is 1 inch long, and was taken in the North Atlantic 

 on April 29, 1876. 



' The recent discovery off the island of Skye of a .'ijiecimeu of Lichia vadiyv is additional evidence of the pelagic 

 habits of the tishes of this genus. 



2 Dr Lutkeu {loc. cit, p. 483) draws on this occasion attention to the fact that the undue creation of nominal 

 species of this genus is the work of Valenciennes, and not of Cuvier, to whom I had attributed it in Catal. Fish., 

 vol. ii. p. 405. This is perfectly true, and I regret so far the oversight on my part, wliich I might have avoided by a 

 more careful examination of the index of vol. ix. of the Hist. nat. des Poissons. However, the fact of Cuvier's 

 tendency of multiplying species, especially tow^ards the end of his life, is, nevertheless, undeniable ; witness his treat- 

 ment of the genera Elacatc, Trachjiwtuis, &c. I fully agree with Dr. Lulken's conclusion that there are in existence 

 probably two species of Dolphins only. 



(ZOOL. CHALL. EXP. — I'.^RT LXXVUI. — 1889.) liii 2 



