AMPELISCIDAE 



89 



Description. Integument smooth, shiny. Head dorsally keeled, but not sharply. 

 Peraeon dorsally rounded, only on the 7th segment with a very faint indication of the 

 dorsal ridge, which becomes distinct on pleon segments 1-3, especially on 3. In the 

 specimens from no. 1 large <S3 are distinctly keeled from peraeon segment 5 to pleon 

 segment 4. Pleon segment 4 with indistinct ridge, but ending in a small point. In young 

 specimens there are 2-3 minute setules on posterior margins of pleon segments 2-4, 

 which get rubbed off in larger specimens. Head with short deflexed rostrum. Corneal 

 lenses 4, the lower pair situate within the lower margin of head, immediately behind 

 bases of 1st antennae, and thus invisible in lateral view. Side-plates 1-3 narrow, 1 pro- 

 duced forwards, 3 shallower than 2. Side-plate 4 much shallower than 1-3, longer than 

 deep, posteriorly produced into a subacute point. Lower margins of 1-4 setose. Side- 

 plates 5-7 successively shallower, 6 and 7 with a few setae on anterior lobes. Postero- 

 inferior angle of pleon segments 1 and 2 rounded, with a few setae, of segment 3 



Fig. 42. Haploops securiger, Brnrd. a. General view. b. Palp of mandible. 



broadly rounded, non-setose. Telson ovate, cleft for three-quarters of its length, lobes 

 contiguous, a single dorsal spinule on each lobe in distal half, and one at apex. 



Antenna 1, 2nd joint i\ times 1st, 3rd short, flagellum reaching to about middle of 

 peraeon. Antenna 2, 5th joint shorter than 4th, flagellum reaching to about end of 

 peraeon. Mandibular palp with 2nd joint slender, nearly linear, 3rd two-thirds as 

 long as 2nd. 



Gnathopod 1, 6th joint nearly as long as 5th. 



Peraeopods 1 and 2, dactyl subequal to 6th joint, peraeopod 2 strongly setose on hind 

 margin. Peraeopod 3, 2nd joint obliquely oval, anterior margin evenly convex, with 

 plumose setae, hind margin proximally lobed, the distal part of margin not in the same 

 plane and thus forming a groove for the reception of 2nd joint of peraeopod 4 (cf . Sars' 

 figure of Haploops tubicola, 1895, pi. lxvii), 5th joint with transverse rows of spinules, 

 posterior apex produced, 6th joint abruptly narrower, the anterior distal apex slightly 

 produced over base of dactyl. Peraeopod 4, 2nd joint with sinuous anterior margin, 

 with plumose setae, hind margin strongly lobed proximally, then concave, apically with 



