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 bnt 

 slightly dilated posteiiorly. Last pair of nropoda with the inner ramns 

 distinctly serrated on the inner edge, outer ramus scarcely lu'oader and Inxt 

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

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

 3 small a[iical siiines. Colour corneous yellow with a tinge of tiesh-colour on 

 tlie mesosome, ovaries dark bluish. Length s mm. 



liciiiayls. — As recently pointed out by Dr. Hansen, this form has 

 been confounded by Boeck and subse([uent authors with the following species. 

 Believing, however, the Lysianassa midouiniana of Sp. Bate to be specifically 

 distinct, lie has proposed for the form iiere described anotlier name, viz., that 

 of A. negledus. In my opinion, there can be little doubt tluit in reality 

 both are identical. 



Occurrence. — I have met with this form ratlier plentifully both on 

 tlie 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 numeroiis 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? 



Distrihution. — British Islands, Denmark, France, Shetland; Adriatic 

 (Heller). 



11. Aristias tumidus, (Kriiyer). 



(I'l. IS, lig. I). 



Anontjx tumidus, Kioycr, Naturhist. Tidssk. 2 R., Bd. 2. p. Ul. 



Syn ; IMenigrates arctious, Sclmeidcr. 



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

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

 Lateral corners of the last pair of epimeral i)lates of metasonie rectangulai', 

 posterior edge irregularly serrated. J^yes comparativeh' larger than in A. 

 midoiiininnus, distinctly constricted in the ujiper part, ])igment black. Superior 

 antenna^ relatively shorter than in that species, flagellum composed of a less 

 numlier of articulations. Anterior gnathopoda very like those oi'gans in A. 

 (Mtdwiiiiianiw, but the propodos com])aratively shorter and stouter. Posterior 

 gnathopoda less slender. Pereiopoda also comparatively shorter, prcqiodal 

 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 



