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 } 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 Ist, 3rd 4 2nd, flagellum 
nearly equal to peduncle, setose, ca. 8-jointed in ¢, 6 in 9, accessory 
flagellum 2-jointed, the 2nd small. 
Second antenna not as long as Ist, 4th and 5th peduncular joints 
subequal, flagellum 1} times last peduncular joint, 5-jointed in ¢, 
4in 9. 
Mandible with the molar prominent but not very acuminate, like 
that of A. antarcticus Walker. 
The other mouth-parts normal. 
First gnathopod, 2nd joint slightly contracted in the middle, 6th 
joint a little longer but narrower than 5th, its inferior margin minutely 
spinulose, 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 shghtly 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 Ist joint of outer ramus, 2nd joint half 
length of Ist. 
Length: @ 4mm.; 2 3 mm. 
Colour: In spirit, reddish pink. 
Locality: Cape Hangklip NE. ¢ E., distant 27 miles (False Bay). 
105 fathoms. 1 ¢, several ovigerous 2 2 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 Ascidians (A. neglectus) or in sponges 
(A. topsenti Chevreux). Bonnier records his A. commensalis 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, Rend. Soc. Borbon. n. s., vol. 2, p. 169. 
1857. x id. Mem. Ac, Napoli. vol. 1, p. 188. 
