122 Annals of the South African Museum. 



inferior angle of 3rd pleon segment quadrate, hind margin finely 

 serrulate. 



Telson as broad as long, cleft for f length, lobes slightly dehiscent, 

 each apex with a stout spine set in a notch, outer lateral margins 

 strongly convex. 



First antenna, 2nd joint half length of 1st, 3rd f 2nd, flagellum 

 nearly equal to peduncle, setose, ca. 8- jointed in $ , 6 in ? , accessory 

 flagellum 2-jointed, the 2nd small. 



Second antenna not as long as 1st, 4th and 5th peduncular joints 

 subequal, flagellum H times last peduncular joint, 5- jointed in $ , 

 4 in ? . 



Mandible with the molar prominent but not very acuminate, like 

 that of A. antarcticus Walker. 



The other mouth-parts normal. 



First guathopod, 2nd joint slightly contracted in the middle, 6th 

 joint a little longer but narrower than 5th, its inferior margin minutely 

 spiuulose, with a short spine in the middle and 2-3 at the apex. 



Second gnathopod, 6th joint shorter and very slightly narrower than 

 5th, both joints setose. 



First and second peraeopods normal. 



Third to fifth peraeopods, hind margin of 2nd joint slightly convex, 

 with 3-4 slight serrations in 3rd and 4th peraeopods, 6 in 5th. 



First to third uropods with a short spine at end of peduncles, all 

 the rami minutely spinulose on both margins, both rami of 3rd lanceo- 

 late, inner ramus longer than 1st joint of outer ramus, 2nd joint half 

 length of 1st. 



Length : <$ 4 mm. ; ? 3 mm. 



Colour : In spirit, reddish pink. 



Locality: Cape Hangklip NE. i E., distant 27 miles (False Bay). 

 105 fathoms. 1 <$ , several ovigerous $ $ and immature specimens, 

 s.s. " Pieter Faure." 26/2/02. (S.A.M. No. A3816.) 



All the species of this genus seem to lead a semiparasitic existence 

 either in the branchial cavity of Ascidiaus (A. neglectus) or in sponges 

 (A. iopsenti Chevreux). Bonnier records his A. commensaUs as living 

 in association with a sponge and an Asteroid. The present species 

 was found associated with an Ophiuroid occupying cavities and 

 galleries in a sponge covering the gastropod Tritonium murrayi (Smith). 



GEN. ICHNOPUS Costa. 



1853. Ichnopus Costa, Eend. Soc. Borbon. n. s., vol. 2, p. 169. 

 1857. id. Mem. Ac. Napoli. vol. 1, p. 188. 



