244 Mr. R. I. Pocock on the Species of 



Measurements in millimetres. — Total length 81; length 

 and width of carapace 13 ; distance of eyes from front border 

 8*5 ; width of hand 12*2 ; length of hand-back 7°5, of movable 

 finger 13-5. 



Loc. Port Elizabeth, Algoa Bay (J. M. Leslie). 



Resembling 0. opinatus, Sim., and Wahlbergi, Thor., in 

 having the vesicle granular, but certainly differing from both 

 in having the eyes some distance behind the middle of the 

 carapace, the last abdominal sternite granular, a smaller 

 number of pectinal teeth, &c. ; but of the two it appears to be 

 much nearer to 0. opinatus, which it resembles in the arma- 

 ture of its feet. 



Opisthophthahnus breviceps, sp. n. 

 (PL X. figs. 3, 3 a.) 



Colour of trunk above a uniform deep reddish brown ; cara- 

 pace the same colour, the interocular area being only a little 

 lighter in the middle and not sharply contrasted with the 

 colour of the rest of the plate ; tail and under surface a little 

 paler than the upper surface of trunk ; legs pale reddish 

 brown ; chelas yellowish red, with the crests heavily black- 

 ened; fingers black ; the upper surface of the hand entirely 

 yellowish red, the colour showing up rather strongly against 

 the generally dingy tint of the trunk ; coxas uniformly 

 reddish brown. 



Carapace short, as wide as long, distinctly shorter than the 

 first two segments of the tail, equalling in length the fifth 

 segment of the tail ; ocular tubercle one third of the length 

 of the carapace from the posterior border ; finely granular at 

 the sides, without any crests of coarse granules defining 

 laterally the interocular area, which is shining and finely 

 punctured, but also, at least in one specimen, very finely and 

 sparsely granular ; median sulcus undivided. 



Terga exceedingly finely granular (shagreened) throughout, 

 the median crest almost absent, but defined by a depression 

 on each side ; the seventh coarsely granular, with two 

 abbreviated crests on each side. 



Sterna, including the first (PL X. fig. 3 a), thickly and 

 coarsely granular throughout, except just upon theantero-lateral 

 angle between the muscular groove and the stigma ; the 

 granules mostly transversely elongate. 



Tail four and a half times the length of the carapace ; 

 upper surface of segments 1 to 3 granular, upper keels of 

 segments 2 to 4 denticulate, the denticulation rather stronger 



