Crustacean Fauna of Soiitli Africa. 107 



1908. Trischizostoma id. S.A. Crust, pt. 4, p. 59. 

 1908. Sexton, Proc. Zool. Soc. Lond. 1908, pt. 2, 



p. 370. 



TRISCHIZOSTOMA. PAUCISPINOSUM: u. sp. 

 (Plate XXVI. Fig. 1.) 



Head plus rostrum a little longer than 1st peraeon segment, rostrum 

 triangular, broader than long, apex subacute, curved downwards. 

 Eyes large, occupying the greater part of the lateral portions of the 

 head, reniforni, not extending above and not nearly meeting on top 

 of head. 



Second peraeon segment a trifle shorter than the first and the 

 following segments. Side-plate 1 small, triangular, almost completely 

 hidden by 2, which is a little deeper than long, 3 also a little deeper 

 than long, larger than 2, 4 a little larger still, almost circular, the 

 anterior, inferior and hind margins forming a nearly even curve, 

 posterior margin excised for 5, which is longer than deep (longest 

 of all the side-plates) and bilobed, 6 a little shorter than 5, 7 large, 

 triangular, deeper than long. 



Pleon segment 4 hollowed at base, pleuron of 1st narrowed below 

 and ending in a small acute point at the postero-lateral angle, of 2nd 

 large, inferior margin straight or slightly emarginate, postero-lateral 

 angle acute, inferior margin of 3rd convex, postero-lateral angle acute, 

 the posterior margin sinuous above the angle. 



Telson a little longer than broad, slightly tapering, cleft to centre, 

 the apices obtuse. 



First antenna reaching to about 6th peraeon segment, 2nd and 3rd 

 joints together equal to half length of 1st, flagellum 20-jointed, 1st 

 joint nearly half as long again as whole of peduncle, its anterior 

 margin densely setose, accessory flagellum 3- jointed, 1st joint f 

 length of 1st flagellar joint, lanceolate, with a few widely spaced setae 

 on both margins, 2nd and 3rd joints very slender, 3rd ^ length 

 of 2nd. 



Second antenna reaching to about end of 3rd pleon segment, 5th 

 joint twice length of 4th, flagellum at least twice length of peduncle, 

 ca. 40-jointed. 



Mandible, trunk distally from palp of more or less even width 

 throughout, cutting edge straight, the angles rounded, palp long, 2nd 

 and 3rd joints subequal, 2nd not or scarcely broader than 3rd, inner 

 margins of both setose. 



