PHOTIDAE 225 



Description. Rostrum obsolete. Ocular angle of head subacute, post-antennal angle 

 acute but not prominent. Eyes obliquely oval. Peraeon segment 2 in ^ twice as long as 

 segment i, and equal to segment 6. Peraeon and pleon dorsally smooth, except for 

 three to four denticles on hind margin of pleon segments 4 and 5 dorso-laterally. Side- 

 plate 1 quadrangular, not produced forwards, 2 larger than either 1, 3 or 4, especially in 

 cT, 3 and 4 quadrangular, scarcely deeper than long, shallower than 2 in both sexes. 

 Postero-inferior angle of pleon segment 2 narrowly, of segment 3 broadly, rounded, 

 both feebly crenulate. Telson subtriangular, broader than long, apex subacute, a spine 

 on each lateral angle, which is rounded. 



Antenna 1 extending back to end of peraeon or 1st pleon segment, 1st and 3rd joints 

 subequal and longer than 2nd, flagellum at least as long as peduncle, 27-32-jointed) 

 accessory flagellum 7-8-jointed. Antenna 2 shorter than antenna 1, 4th joint longest, 

 flagellum subequal to 5th peduncular joint, 12-14-jointed. 



Epistome with a long slender spine extending forward almost to apex of 3rd ped- 

 uncular joint of antenna 2. Mouth-parts normal. 



Gnathopod 1, 6th joint oval, shorter than 5th, palm oblique, smooth, not defined from 

 lower margin, both joints setose, especially on lower margins, finger closing against 

 margin of palm; no sexual differences. Gnathopod 2 in <$ very strong and robust, 2nd 

 joint not or only feebly channelled in front, distal anterior angles not produced in lobes, 

 6th subequal to 5th, palm oblique, smooth, defined by a notch which is formed by the 

 bending inwards of the distal part of lower margin to form a flange, finger shorter than 

 palm, stout, closing on to inner surface of hand, 5th and 6th joints setose, especially on 

 lower margins. In $ considerably less stout than in S , similar to gnathopod 1 , but longer 

 and stronger, finger closing against margin of palm which is not defined from lower 

 margin. In both sexes the distal half (i.e. from 4th joint onwards) of gnathopod 2 is 

 curved inwards across the body. 



Peraeopods 1 and 2 slender, feebly setose, finger just under half length of 6th joint. 

 Peraeopods 3-5 increasing in length; peraeopod 3 similar in both sexes, 2nd joint 

 slender, tapering distally, hind margin serrulate, postero-inferior angle rounded, dactyl 

 half length of 6th joint. Peraeopod 4 in <$, 2nd joint narrow, oval, greater width in 

 centre, hind margin serrulate, postero-inferior angle rounded, dactyl half length of 6th 

 joint; in ?, 2nd joint similar in shape to that of peraeopod 3, though longer. 



Peraeopod 5 in <$, 2nd and 4th joints laminately expanded, 2nd joint expanded on 

 distal half of anterior margin, proximal half spinulose, distal half smooth, hind margin 

 strongly expanded, greatest width in distal half, feebly serrulate, lower margin broadly 

 rounded, 4th joint ovate, expanded on both anterior and posterior margins, in cross- 

 section triquetral, dactyl slightly more than half length of 6th ; in $, 2nd joint similar to 

 those of peraeopods 3 and 4, though longer, i.e. tapering distally, the greatest width 

 being proximally, 4th joint linear as in the other peraeopods. In immature <$ the 2nd 

 joint is elongate-oval, like that of the 4th peraeopod, but slightly longer. 



Uropods 2 and 3 extending slightly beyond uropod 1, no sexual differences in any 

 of them. Uropod 1, upper margin of peduncle strongly spinulose, a strong spine on 



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