192 



densely fringed with slender setae; 4th pair nearly as in Byhlis. Corneal 

 lenses, when present, only two, the inferior pair being quite absent. Antennae 

 in female nearly equal-sized, and densely setous, the basal part of the inferior 

 ones partly concealed; those in male more unequal in length and extremely 

 slender, exhibiting a similar structure as in the males of the genus Ampclisca 

 and ByJjlw. Mandibles about as in ByUif, but with the palp much larger 

 and having the last joint elongated and densely setous. Maxillae scarcely 

 diifering in structure from those in the latter genus. Maxillipeds with the 

 masticatory lobe comparatively smaller, scarcely reaching to the end of the 

 antepenultimate joint of the palp; penultimate joint of the latter with the 

 outer corner produced to a rounded setiferous lobe. Grnathopoda, as a rule, 

 less slejider than in the genus ByUii^, otherwise of much the same structure. 

 The 4 anterior pairs of pereiopoda likewise rather similar to those in the latter 

 genus. Last pair of pereiopoda, on the other hand, rather different, having the 

 basal joint far less dilated, with the posterior expansion very slight, meral 

 and car])al joints laminarl^' dilated, and spinous at the edges, propodal joint 

 and dactylus very narrow. Last jtair of uropoda comparatively more fully 

 developed tlian in the genus ByMit<, and considerably projecting beyond the 

 preceding pairs, rami more or less foliaceous, and setous at the edges, the 

 inner one having besides a niimber of strong denticles inside. Telson of 

 moderate size, and deeply cleft. 



BemarJcs — This genus, established by Prof. Lilljeborg, is chielly 

 characterised by the absolute want of the inferior pair of corneal lenses, and 

 by the structure of the last pair of pereiopoda. In some characteristics, as 

 the structure of last pair of uropoda, and of the telson, it seems to agree more 

 nearly with Ampelisca, whereas in most other structural details it bears a 

 closer relationship to the genus Byl)Vin. The genus is wholly restricted to 

 the northern Ocean, and comprises, as yet, but 4 species, 3 of which will be 

 described in the following pages. 



21. Haploops tubicola, Lilljeborg. 



(PI. 67). 

 Haploops tubicola, Lilljeborg, 0fveis. af Vet. Akad. FOrh. 1855, p. 134. 

 Syn; AiiipeliscH Eschrichtii, Lilljeborg (olim). 

 > Hajiloops cariu.ita, Lilljeborg (adult male). 



Form of body in female rather short and stout, with the back broadly 

 rounded, and quite smooth. Cephalon but little longer than the first 2 

 segments of mesosome combined, frontal part gradually tapering, and trans- 

 versely truncated at the tip, inferior corners blunted. First pair of coxal 



