Euphausiidæ. 



With regard to our earlier knowledge of the development of 

 Euphausiidæ, the following abbreviated account may suffice. 

 In Dana's great work some peculiar pelagic Crustacea are 

 described, being included in 3 different new genera, viz., 

 Calyptopis, Furcilia, and Cyrtopia. The larval character of 

 these forms, however, at once appears on comparing 

 the figures given, and Prof. Claus, who in 1863 published 

 an account of a Mediterranean JEuphausia 1 ), did not indeed 

 hesitate in regarding all these 3 genera as founded merely upon 

 successive larval stages of Euphausiidæ. Besides a figure of 

 the adult form (Euphaiisia Miilleri), he gives a very good 

 figure of a somewhat advanced Calyptopis-stage, drawn from 

 life, and adds some detail-figures of the oral parts. This 

 was the earliest stage at that time observed; butin 1869 2 ), 

 Mr. Metschnikow made known a still earlier stage, and in 

 1871 3 ) the same author was able to demonstrate that the 

 Euphausia begins its free existence as a true Nauplius, which he 

 believed was hatched from some peculiar pelagic eggs ob- 

 tained at the same time in the tow-net. In 1885 the 

 present author communicated in his account of the Schizo- 

 poda of the Challenger Expedition descriptions and figures 

 of the larval development of several exotic Euphausiidæ, 

 and pointed out the successive changes, both in the out- 

 ward appearance and int he structure of the several appendages, 

 the earliest stage described answering to that at first observed 

 by Mr. Metschnikow, and named by him Metanauplius. In 

 recent times a preliminary paper on the metamorphosis of 

 British Euphausiidæ has been published by Messrs. Brook 



1 ) Zeitschrift f. wissensch. Zoologie, XIII, Bd. 3 Hft. 



2 ) Zeitschrift f. wissensch. Zoologie, Vol. 19. 



3 ) Zeitschrift f. wissensch. Zoologie, Vol. 21. 



