SEVEN STAGES OF LARVAL LIFE 265 



neglecta (Kroyer), and that Thysanoessa tenera, Sars, 

 should be named Thysanoessa longicaudata (Kroyer). 

 The latter species was supposed by Sars to belong to his 

 genus Boreophaiisia, on the faith apparently of Kroyer's 

 figures drawn from a defective specimen. Both neglecta 

 and longicaudata are known from British localities. 



Nematoscelis, Sars, 1883, agrees in many respects with 

 Thysanoessa, but has the second maxillipeds, or first legs, 

 as Sars calls them, far more remarkably elongated and 

 almost filiform. In the type species, Nematoscelis megalops, 

 Sars, they are described as having little or no armature, 

 except a bunch of peculiar spmiform setas at the apex. 

 But Norman points out that in British specimens the 

 fourth joint has several hooked spines, which look as if 

 they might hold the sixth joint when bent back upon the 

 fourth. Should this form hereafter prove distinct, he pro- 

 poses for it the name borealis already published, but with- 

 out description, in 1872. The genus is distinguished by the 

 enormous development of the eyes, ' of larger size, perhaps, 

 than in any other known form of Podophthalmia,' the re- 

 mark applying to the actual eyes, and not to the stalks, 

 which are quite short. 



Sti/locheiron, Sars, 1883, has the third maxillipeds, or 

 second legs, greatly produced, the two terminal joints 

 being armed with spiniform bristles and spines, and the 

 two forming together a kind of grasping organ. The last 

 pair of legs are quite rudimentary, and the two preceding 

 pairs are incomplete. In this genus the mandibles have 

 110 ' palp,' the first maxillae no exopod, and the first 

 maxillipeds no epipod. The ovisac is single. One of the 

 species, Stylockeiron longicorne, Sars, has been taken both 

 in the Mediterranean and south of the Cape of Good 

 Hope. Chun notes that in his mastigophorum the lumi- 

 nous organs are bright red. 



Messrs. G. Brook and W. E. Hoyle follow up the 

 labours of Glaus, Metschnikoff, and Sars, by tracing the 

 Euphausid larva through seven stages (1) the Nauplius, 

 with body oval, unsegmented, median unpaired eye, first 

 antennas (long) simple, second antennas (long) and man- 



