4.*>ti lAc.i; sK(X'.siii:i{(j 



majority of sprcirs tl\t' truiiK" is ciiiisidi'nilily stroii^iT Mtid also soiiicwliat loiijiiT than in tlic 

 lemale ami is luniisln'tl witii vciy iiuiiicrous sensorial lihrnnits aioiifi; almost its whole leii^tli; 

 the six distfll ones of those filannMiIs are piaetieally (|iiite lil<e ihe six distal seiisoiial lilaiiieiits 

 on this hristle in the lemale, with wliuli tlie\- ai'e alsd |iriil)alil\ li(ini(iloL;iiiis; the olhei- sensot'ial 

 Hlanionts. tho accessory ones, are ahoiit as lon^ as hut somewhat narinwcr llian I hose just 

 mentioned: they are situated on one si(h> — on the anterior-medial siih' nl the bristle alon<i; 

 the proximal part of the stem of the hristle. and are arranjied more (ui all sides distally; they 

 are also, at least partly, arranged in a number of transversal rows (in the cases investif>ated ahout 

 thirteen to twenty rows were observed). In a nimdier- nl lorms {<■(. .1. cur/a p. fiol ol this 

 treatise) this hristle shows (piite the .same type as in the female. (I. W. .Mri,l,i;ii describes 

 (1908. p. 93) a species A. (urih's ( .1. ij/dc/n/is. (1. W. .Ml i,i.i:i;. litl'i). which, as is 

 shown on p. 503 of this treatise, is very closely related to A. curta; the male of this 

 species appears to be characterized by having this bristle rather weakly developed and 

 provided witli only a few sensorial filaments, according to the text ,,etwa vier", according 

 to the accompanying figure five (pi. 8, fig. 15).* The a-claw is ratliei' considerably 

 weakened, but is distinctly claw-like. The b-bristle is only rather slightly lengthened; its sen- 

 sorial filaments, which are only slightly oi- else not at all increased in number (in all the cases 

 investigated the number was increased by only a single filament), are somewhat more uniformly 

 distributed along the pro.ximal half of the bristle. The c- and f-bristles are of the same type 

 as in the female, but are enormously lengthened, being about V/^ times or V/., times as long as 

 the shell, and have a considerably greater number of sensorial filaments. The g-bristle is 

 niily slightly longer and the number of its sensorial tilani(>nts is rather slightly greater than 

 in the female. The f-bristle is not. as in the female, directed rectangularly forward, but 

 in the longitudinal direction of the antenna, the b-, c-, and g-bristles are also ])ointed some- 

 what less forward than in the female. On the end joint there is latero-posteriorly a powerful 

 chitinous verruca, which is quite absent in the female (cf. fig. 8 of A. norvegica). From it the 

 e-bristle issues basally-anteriorly ; this bristle is of the same type as in the female; it always 

 seems to penetrate between the c- and g-bristles and is held medially of these bristles (cf. 

 fig. 8 of A. norvegica. fig. 11 oi A. Griinaldi and fig. 7 of A. curta). I could not observe any 

 trace of the d-bristle. AMiether this latter bristle is developed in the males of such forms as 

 have it developed in the females, I cannot decide, as no such forms were present in my collection. 

 The pilosity is weaker than in the females. 



Second antenna: — 



Female: — The p r o t o p o d i t e has a very short bristle distally-medially close 

 to the exopodite; this bristle was observed in all the species dealt with in this treatise except 

 A. Grimaldi and its variety. The exopodite is about as hmy as the jirotopodite; the 

 proportions between its joints are as follows: 



I : 11 : III : IV : V : VI : VII : VIII : IX = 30 : 6 : 3 : 3 : 3 : 3 : .3 : 3 : 2, 

 i. e. the first joint is about as long as or somewhat longer than all the following joints together, 

 the second joint is about as long as the total length of the two following joints. The first joint 



* (1. W. MiLi.F.R cvidiMitly coiititi'il oMi- (if till' lihinionts as tlii' distnl {p.iil nl' Ihr lirisllr. 



