117 



x 



Epistome not at all projecting. Anterior lip produced in front to an acutely 

 triangular deflexed lobe. Mandibles comparatively small, cutting edge simple, 

 obtuse; molar expansion obsolete, palp very large and originating nearer the 

 tip than the base of the mandible. First pair of maxillse with the masticatory 

 lobe rather large and obliquely truncated, terminal spines unusually small, 

 claw-like; basal lobe rounded oval, with several apical bristles, palp normal. 

 Second pair of maxillse with both lobes short and obliquely truncated at the 

 tip. Maxillipeds with the masticatory lobe very small, scarcely larger than 

 the basal lobe, and provided with slender setae on the edge; palp rather 

 robust. Anterior gnathopoda slender and elongate, sparingly setous, propodos 

 forming together with the dactylus a perfect chela. Posterior gnathopoda 

 stronger than usual, propodos dilated distally, subcheliform ; dactylus large 

 and curved. Pereiopoda powerfully developed. Last pair of uropoda reaching 

 beyond the preceding pair, rami lanceolate. Telson oblong, deeply cleft. 



Remarks. - 'Miis genus established by the Rev. Mr. Norman, is pro- 

 minently distinguished from oil other Lysianassidse by the peculiar chelate 

 character of the anterior gnathopoda, as also by the powerful structure of the 

 propodos of the posterior ones. Moreover the oral parts exhibit in their 

 structure several peculiarities, which would seem to point to a semiparasitic 

 habit. Besides the species described in the sequel, the Opis leptocliela of 

 Sp. Bate undoubtedly belongs to the same genus, and the Rev. Mr. Stebbing 

 has described another species, E. Normani, from the Challenger Expedition. 



53. Euonyx chelatus, Norman. 



(PL 40, fig. 1). 



Euonyx chelatus, Norman, Report of the British Association for the Advancement of Science 



f. 1866, p. 202. 



Body rather strong and thickset, with broadly rounded back. Cepha- 

 lon somewhat longer than the 1st segment of mesosome, forming anteriorly 

 between the bases of the superior antennse a blunt curved rostral projection, 

 lateral corners but slightly produced and nearly rectangular. First pair of 

 coxal plates extremely small and rudimentary; the 3 succeeding pairs very 

 large, fully 3 times as deep as the body; the 4th considerably expanded 

 below and jutting out posteriorly as an acute lobe; 5th pair likewise rather 

 large, fully as deep as broad. Last pair of epimeral plates of metasome pro- 

 duced at the lateral corners to a short and blunt point. First segment of 

 urosome deeply impressed at the base dorsally and exhibiting behind the 

 depression a high and compressed hump-like projection, fives oblong oval and 

 somewhat constricted at the middle, pigment chalky white. Superior antennse 



15 b Crustacea. 



