48 



tapering, almost l)are, and but sliglitlj^ projecting beyond tlie latter, terminal 

 joint vingniform. Aaiterior gnathof)oda rather robust, prcipodos tumid at the 

 base, oljpyriform and finely serrated on the inferior edge, palmar border not 

 distinctly defined, daotylus short. Posterior gnathopoda very slender and 

 densely liirsute in the outer part, propodos narrow oblong, produced at the 

 tip Ijeneath the I'udimentary dact^dirs so as to I'onn a minute chela. Pereio- 

 poda of nearly uniform size, rather strong, basal joint of the 3 posterior pairs 

 not very nuich dilated. Uropoda with the rami lanceolate and jiartly serrated 

 on the edges, last pair slightly reaching beyond the preceding pair, outer 

 ramus the larger and having a distinct terminal joint. Telson comparatively 

 short, deeply cleft. 



Remarlis. — This is a very distinct genus, difFering, as it does, espe- 

 cially in the structure of the oral jiarts, very decidedly' from tlie otlier Lysia- 

 nassidse. Besides the 2 species described below, the Lyskmassa ciliata of 

 Heller undoubtedly belongs to this genus, and probably also L. Ir/miilis Costa. 



10. Aristias audouinianus, ^Sp. Bate). 



(PI. 17, fig. 2). 



Lysianassa audouiniana , Sp. Bate, Brit. Assoc. Ecp. 1855. 



Syu; Aristias tumidiis, Boeck (not Krciyer). 



Body short and robust, with broadly roiuidod back and shai'jily defined 

 segments. Cephalon very slioi't, ti'uncated in front, lateral corners ahnost 

 rectangular and slightly produced at the tip. First pair of coxal plates very 

 small and to a great extent covered by the succeeding paii'; the latter only 

 little deeper than the body; 4th pair scarcely broader than 3rd and only 

 very sliglitly emarginated posteriorly, inferioi' \rM-t narrowly rouniled; otli 

 pair much more broad than deep. Last jiair of epimeral plates of meta- 

 some naiTdwly rounded at the infero-posterior corners, posterior edge smooth. 

 Eyes rounded o\al, placed near the lateral corners of the cephalon, pigment 

 black with a whitish coating. Superior antennae about the length of the 

 cephalon and the 3 anterior segments of tlie mesosome combined, 2nd joint 

 of tlie peduncle twice as large as the 3rd, and lioth together al)Out half the 

 length of the 1st joint; flagellum only little longer than the peduncle, 10- 

 articulate, 1st joint rather large; accessory appendage half the length of the 

 flagellum, o-articulate. Inferior antennae having the flagellum aboitt as long 

 as the peduncle and 'J-articulate. Anterior gnathopoda with the propodos 

 fully as long as the carpus, inferior edge finely serrated and, besides, armed 

 with 4 short spines. Posterior gnathopoda nearly twice as long as the 

 anterior and very slendei', propodos ahout Imlf the length of the carpus, both 



