382 Annals of the South African Museum. 



Maxilliped 7-jointed. First peraeopod stout, 6th joint ovate. Second 

 to fourth peraeopods longer and more slender, 6th joint slender, finger 

 straight. Fifth to seventh peraeopods stout. Uropod with a minute 

 ramus. Vasa deferentia opening by a single median process on first 

 pleon segment. 



The first portion of the generic name refers to the uncleft lateral 

 margins of the head. 



HOLIDOTEA FNICORNIS n. Sp. 



(Plate XVI. Figs. 18-23.) 



Body smooth but with a thick felty covering of dirt and often 

 Diatoms and Vorticella ; more convex in <$ than 9 Head twice as 

 broad as long, anterior margin broadly excavate, lateral margins 

 entire, straight or slightly emarginate, autero- and postero-lateral 

 angles quadrate ; central portion of head convex and gibbous, simple 

 in 9 but armed in $ with a large flat triangular tooth or horn arising 

 from the posterior margin, the posterior face of the tooth concave, 

 apex subacute, sides denticulate. Eyes prominent, dorsal, circular. 



Peraeon segments 1-4 subequal in length, 2 and 3 wider than 1 and 

 4, segments 5-7 decreasing in width, 5 abruptly narrower than 4, all 

 the segments dorsally smooth except 5-7 in ^, each of which bears 

 2 obscure submediau tubercles. Side-plates distinct 011 all the seg- 

 ments except 1st, those on 2-4 subtriangular in $ , the antero-lateral 

 angles being prominently produced and subacute, quadrate and not so 

 produced in 9 > 5-7 in both sexes shallow, with rounded margins. 

 Segment 4 in $ with a median ventral spiuiform projection. 



Pleon ovate, widening slightly and then tapering to a subacute apex, 

 lateral margins evenly convex, with 2 little notches at the base indi- 

 cating the 2 incomplete basal sutures, both rather indistinct ; dorsal 

 surface in <$ with 2 short submedian keels (being a continuation of 

 the ornamentation on the peraeon segments 5-7) and a circular median 

 tubercle just beyond the centre, in 9 smooth. 



Antenna 1 reaching to middle of 3rd joint of antenna 2, 1st joint 

 stout, 2nd nearly as long but more slender, 3rd much shorter than 

 2nd, flagellum as long as 2nd, tipped with setae. 



Antenna 2 reaching to end of 2nd peraeou segment, 2nd joint stout, 

 3rd-5th becoming successively more slender and a little longer, 2nd 

 and 3rd joints triangular in section, the three margins denticulate, 

 more strongly so in J than 9 ; surface of 4th, especially towards apex, 

 scabrous, flagellum subequal to 5th joint, 2-joiuted, 2nd joint a little 

 shorter than 1st and tipped with a few setae and a gently curved spine. 



