242 " THETIS " SCIENTIFIC RESULTS. 



peraeon unequal, the first much the longest. Epimera acute, 

 widely separated from each other, and their union with the 

 lateral tergal margins indistinct. Pleon much narrower than 

 the peraeon, consisting of two segments, with well developed 

 epimera on the first of the coalesced segments. Terminal 

 segment large, with a lateral pair of epimera-like processes and 

 a tridentate distal border. 



Eyes round, widely separated, lateral and prominent. 



Superior antennae with the basal joints dilated; the flagellum 

 shorter than the peduncle. 



Inferior antennae with a slender cylindrical peduncle, a little 

 shorter than the flagellum. 



Mandibles stout, cutting edge terminating in two or three 

 blunt denticles, subtended below with a tuft of simple spines. 

 Molar tubercle broad, short, with a few subterminal spines. 



Palp three-jointed. 



Anterior maxillae with the masticatory lobe somewhat narrow, 

 tipped with curved simple spines ; basal lobe furnished at the 

 apex with four unbranched filaments. 



Posterior maxillae three-lobed, the masticatory lobe rather 

 broad and carrying numerous pectinated spines at the summit ; 

 paired lobes narrow, surmounted apically with simple spines. 



Maxillipedes slender, basal part rather narrow ; masticatory 

 lobe with a blunt curved filament on its inner border and a series 

 of pectinated spines at the summit; palp consisting of five joints, 

 the first short, second to fourth each with a large superior 

 setiferous lobe, fifth subcylindrical and apically setose. 



Anterior pair of legs shorter and stouter than the posterior ; 

 dactylus of all the pairs with a small secondary subterminal 

 claw. 



Pleopoda foliate; all except the last pair densely ciliate. 



Uropods short, with the mobile ramus minute. 



CASSIDINELLA INCISA, sp. nov. 



(Figs. 23a-^.) 



Station 55. 



Body less than twice as long as broad, narrowing rather rapidly 

 from the fifth peraeon segment to tlie end of the telson. Central 

 region of segments transversely and longitudinally convex. 



