_ (579 



in length the carpus, and oval in form, with the lower edge somewhat curved 

 in front and finely serrulated, being, moreover, armed with 3 or 4 small den- 

 ticles. Posterior gnathopoda, as usual, more elongated and slender than the 

 anterior ones, propodos exceeding half the length of the carpus, and imper- 

 fectly chelate at the tip. Pereiopoda short and stout, with the meral joint 

 somewhat expanded, and the carpal joint very short, propodal joint about the 

 length of the 2 preceding joints combined, and, as in the genus Aristias, form- 

 ing at the end, below the dactylus, a dentiform projection; basal joint of 

 last pair shorter than the remaining part of the leg, and oval in form. Last 

 pair of uropoda with both rami finely denticulated on the edges, the inner 

 one but little shorter than the outer. Telson nearly twice as long as it is 

 broad at the base, and gradually tapering distally, tip narrowly truncated, with 

 the lateral corners slightly produced. Colour yellowish, with a more or less 

 distinct, darker shadow on the anterior part. Length of adult female 3 l /z mm. 



Remarks. - There cannot be any doubt that the above-described form 

 is that originally recorded by Sp. Bate as Lysianassa audouiniana, and that 

 Perrierella crassipes of Chevreux & Bouvier is the same species. In its out- 

 ward appearance it bears a very strong resemblance to the species of the 

 genus Ariettas, and it is only on a closer anatomical examination that some 

 differences in the structure of the several appendages are revealed, showing 

 it to be, in reality, generically distinct. 



Occurrence. I have met with this form of late years not infre- 

 quently in the Trondhjemsfjord in moderate depths, and occasionally also off 

 the west coast of Norway. 



Distribution. British Isles (Sp. Bate), Kattegat (Meinert), coast of 

 France (Chevreux), Mediterranean (Chevreux). 



Page 56. Hippomedon denticulatus 



Distribution, Greenland (Hansen). 



Page 59. Add another species : - 



Hippomedon robustus, G. 0. Sars, n. sp. 



(Suppl. PI. Ill, fig. 1). 



Body of a comparatively robust form, being less compressed than in 

 the other species. Cephalon about the length of the first 2 segments of 

 mesosome combined, lateral corners acutely produced. Anterior pairs of coxal 

 plates nearly twice as deep as the corresponding segments; 1st pair somewhat 

 expanded distally, and broader than the 2nd; 4th pair much broader than the 



