REPORT ON THE SCHIZOPODA. 



G3 



extensive use of the surface-net on the Expedition proved highly successful. In regard to 

 the capture of Euphausidians this may pre-eminently be said to be the case, scarcely a single 

 haul failing to yield some of the forms comprised in this group, either adult or larval. 

 I have carefull)^ gone over a vast number of surface gatherings, kindly sent me by Dr. 

 John Murray, and from these have selet^ted every form that belongs to the Euphausiidse. 

 A large proportion of the specimens thus l)rought together represent various stages of 

 development : and it has therefore been a matter of no slight difficulty to determine in 

 each case with full certainty whether the specimens should be regarded as adults, or 

 whether merely as younger animals. I have been equally perplexed in attempting to 

 refer the larval forms accurately to the several species. Meanwhile, a careful study of 

 numerous specimens has finally enabled me to trace the development of at least three 

 different forms belonging to as many genera, and I shall give a detailed account of these 

 researches when treating of the development of the Euphausiidse. 



The total number of species represented in the collection amounts to no less than 

 twenty-seven, comprising seven distinct genera, of which four are new. 



I give below a synopsis of the genera, worked out from the structure of the legs. 



Both the two posterior pairs quite rudimentary, Euphamia, Dana. 



nearl}' uniform in 

 structure, and simi- 

 lar in appearance 

 to the maxUlipeds. 



Less 



Last pair only rudi- 

 mentary; penulti- 

 mate pair 



\ of sime appearance as 

 I preceding, 



I with outer joints of 

 [ stem confluent, 



All the legs distinctly developed, 



somewhat unequally 

 developed, one of 

 the anterior pairs < 

 being greatly elon- 

 aate. 



First pair of legs greatly 

 produced and 



rather strong, the two 

 last jointsarnied with 

 spiniform hrisiles on 

 both margins, 



very slender, filiform, 

 naked, with only a 

 tuft of apical biistles, 



Second pair of legs greatly produced; penulti- 

 mate joint dilated, and forming, togetlier w'ith 

 the last one, a kind of prehensile liand, 



Thijsanopoda, il.-Edw. 



Nyctiphanes, G. O. Sars. 

 Bentketiphmisia^ n. gen. 



Thysanoessa, Brandt. 

 Nematoscelis, G. O. Sara. 

 Styloeheiron, G. 0. Sars. 



Genus L Eupliausia, Dana, 1852. 

 Euphamia, Dana, United States Exploring Expedition, vol. xiii., Crustacea, part i. p. 639. 



Generic Characters. — Carapace with autero-lateral angles Init slightly produced, rostral 

 projection, as a rule, small. Tail powerfully developed. Eyes of normal structure. Anten- 

 nular peduncle alike in both sexes, cylindrical, basal joint sometimes provided at the end 

 superiorly, with a small lappet ; both flagella elongate, and consisting of numerous joints. 



