51 



not very large, masticatory lobe narrow oval, basal one acutely 1;i] it-ring, 

 palp slender, setous. Anterior gnathopoda of moderate si/e. subcheliform ; 

 posterior ones rather slender, with the propodos slightly produced beneath 

 the minute dactylus. Pereiopoda slender, basal joint of the )> posterior pairs 

 very large and laminar. Last pair of uropoda small, scarcely reaching bcvond 

 tlie preceding pair; rami not setous nor denticulate, subdual in size, 1 1n- 

 cuter with a distinct spiniform terminal joint, Telson sipiamiform. entire. 



Remarks. This genus is well characterised by the peculiar laminar 

 form of the penultimate peduncular joint of the inferior antennae, l>v the 

 digitiform projecting anterior lip, and by the coarse structure of the mandibles. 

 In the form of the telson it agrees with Liiximmxxtt, but is otherwise very 

 different, The sexual differences are somewhat analogous to those described 

 above in the genus Acidostoma, the superior antennas only being modified in 

 the male, and not, as is usual, the inferior. With thai genus it also agrees 

 in the full development of the accessory appendage of the superior antenna-. 



12. Lysianella petalocera, G-. 0. Sars. 



(PI. 18, fig. 2). 

 Lysianella petalocera, G. O. Sars, Oversigt af Norges Crustaoeer, I, p. 78, PI. 3, fig. 3. 



Body of female, moderately slender, that of male considerably stouter, 

 the mesosome -being much shorter in proportion to the metasome. Cephalon in 

 female about the length of the first segment of the mesosome, with the lateral 

 corners somewhat projecting and subangular, in male much deeper and having 

 the lateral corners less projecting. The 4 anterior pairs of coxa! plates aboul 

 twice as deep as the body; 4th pair distinctly emarginated posteriorly with 

 the inferior part considerably dilated; 5th pair scarcely dec] MM- than they are 

 broad. Last pair of epimeral plates of metasome rather large and obtusely 

 rounded at the posterior corner. F.yes oval, dark purplish hrowii, with a 

 reddish coating; in male considerably larger than in female. Superior antennae 

 in female about the length of the cephalon and the '2 first segments of the 

 mesosome combined; peduncle not very strong, first joint about twice the 

 length of the other two combined; flagellum rather slender, S-articulate, 1st 

 joint about the length of the 2 succeeding ones combined; accessory appendage 

 a little shorter than the flagellum, but scarcely more slender, 4-art iculate. 

 Superior antennas in 'male much stronger, the peduncle being considerably 

 tumeficated and the 1st joint of the flagellum very large and densely clothed 

 with long sensitive hairs. Inferior antenna 1 with the penultimate joint of the 

 peduncle rounded oval, anterior edge strongly curved, llagellmn 8-articulate. 

 Anterior gnathopoda with the propodos rather narrow, about the length of 



