51 



appendages to the anterior maxillipecls. These species were comprised within a 

 particular sub-genus, to which the above-mentioned name was assigned. In my 

 opinion, this sub-genus ought certainly to be raised to the rank of a true genus, 

 as it also exhibits in several other respects well-marked differences from the type 

 of the genus Scolecithrix, S. dance (Lubbock). One of the species included in 

 this genus, viz., A. typica, Scott, has since been removed by Dr. Giesbrecht, 

 who considers it to be the male of a species of the genus Xanthocalanus. The 

 other 3 species are, however, undoubtedly congeneric, and one of them, A. magna, 

 Scott, I now consider to be identical with the form I have described from 

 Nansen's Polar Expedition as Scaphocalanus acrocephalus. Another polar form, 

 likewise described in my Account of the Crustacea of that Expedition, viz., Scoleci- 

 thrix brevicornis, has turned out, on a closer examination, to belong to the same 

 genus. According to more recent investigations, both these forms are referable 

 to the fauna of Norway, and they will therefore be described below. 



21. Amallophora magna, Scott. 



(PI. XXXIV & XXXV). 



Amallophora magna, Th. Scott. Eeport on Entomostraca from the Gulf of Guinea. Transact. 

 Linn. Soc. London, Vol. IV, Part I, p. 55, PI. IV, figs. 59. 



Syn: Scolecithrix cristata, Giesbrecht. 

 ,. Scaphocalanus acrocephalus, &. 0. Sars. 



Specific Characters. Female. Body moderately slender, with the anterior 

 division pronouncedly navicular in form, being gradually attenuated anteriorly; 

 combined cephalosome and 1st pedigerous segment occupying fully half the length 

 of the entire body. Frontal part, seen laterally, narrowly rounded and surmounted 

 by a very distinct, helmet-shaped crest. Lateral parts of last segment of meta- 

 some slightly angular below. Urosome equalling in length about 1 / s of the anterior 

 division, genital segment scarcely longer than the succeeding one. Caudal rami 

 very short, about as long as they are broad, apical seta3 much elongated, especially 

 the innermost but one. Eye apparently very small. Anterior antennae, when 

 reflexed, reaching about to the end of the anterior division. Anterior maxillipeds 

 with the pedicellated terminal appendages comparatively small. Last pair of legs 

 imperfectly 3-articulate, middle joint very small and not distinctly defined from 

 the terminal one. 



Male rather more slender in form than female, frontal part somewhat 

 abruptly contracted, but without any trace of a crest. Last segment of metasome 

 with the lateral parts rounded off. Urosome considerably longer than in female, 



