49 



densely setous on both edges. Pereiopoda rather elongated, basal joint of 

 the posterior pair shorter than the remainder part of the leg, meral joint but 

 slightly dilated posteriorly. Last pair of uropoda with the inner mums 

 distinctly serrated on the inner edge, outer ramus scarcely broader and but 

 little longer than the inner. Telson longer than it is broad, cleft beyond the 

 middle, the incision rather broad, terminal lobes narrow and armed each with 

 3 small apical spines. Colour corneous yellow with a tinge of tlesli-eolonr on 

 the mesosome, ovaries dark bluish. Length 8 mm. 



Remarks. - - As recently pointed out by Dr. Hansen, this form lias 

 been confounded by Boeck and subsequent authors with the following species. 

 Believing, however, the Lysianassa audouiniana of Sp. Bate to be speeiiieally 

 distinct, he has proposed for the form here described another name, viz., that 

 of A. neylcctus. In my opinion, there can be little doubt that in reality 

 both are identical. 



Occurrence. - I have met with this form rather plentifully both on 

 the south and west coast of Norway, at least up to the Trondhjemsfjord, in 

 depths varying from 20 to 150 fathoms. Very frequently it is found within 

 the branchial sac of Ascidise, thus leading a semiparasitic life. It is very 

 strange that among the numerous specimens collected not even a single male 

 could be detected. Is it that the sexual difference in this form is so very 

 slight as quite to escape attention? 



Distribution. - British Islands, Denmark, France, Shetland; Adriatic 

 (Heller). 



11. Aristias tumidus, (Kroyer). 



(PI. 18, fig. 1). 



Anonyx tumidus, Kroyer, Naturhist. Tidssk. 2 R, Bd. 2, p. Hi. 

 Syn : Menigrates arcticus, Schneider. 



Very like the preceding species, but with the body a little more slender. 

 Cephalon with the lateral corners bluntly rounded, not drawn out at the tip. 

 Lateral corners of the last pair of epimeral plates of metasome rectangular, 

 posterior edge irregularly serrated. Eyes comparatively larger than in A. 

 awloumian-us, distinctly constricted in the upper part, pigment black. Superior 

 antennae relatively shorter than in that species, nagellum composed of a Les 

 number of articulations. Anterior gnathopoda very like those organs in 

 <in<louiniunu, but the propodos comparatively shorter and stouter. 

 gnathopoda less slender. Pereiopoda also comparatively shorter, propodal 

 joint in all produced at the tip, beneath the dactylus, to a short tooth-like 

 process, meral joint in the 3 posterior pairs considerably dilated, with the 

 posterior angle produced almost to the end of the carpal joint, basal joint in 



