64 ON THE BRACHYUROUS DECAPODS OF THE CAPE. 
Fam. THELPHUSID, M. E. 
Sub-genus. TueLpuusa, Lat. 
Sp. 16. ( 

) Thelphusa perlata, M. #. 
Thelphusa perlata, M. KH. Hist. Nat. des Crust. vol. i. p. 13. 
Nore. This crab is common in all the rivers of southern Africa, and grows to the size of nearly 
three inches long. The male has a much more convex shell than the female, and in aspect 
resembles much a Gegarcinus. The pearly tubercles of the anterior margin of shell are also 
still more small and evanescent than in the female. I may take this occasion to observe, that 
in my cabinet I separate those species of Thelphusa, which, like the present, have a transversal 
crest in front of the shell, and call them Potamonautes. They are easily distinguished from 
true Thelphuse, of which the type is the European species Thelphusa fluviatilis. 
Fam. GONOPLACID, M. E. 
Sub-genus? Crxistoroma, Dehaan. 

Spe. 17. ( ) Cleistotoma Edwardsii, 7. s. 
Descr. Cleistotoma oculis magnis, testa levi haud pilosa lateribus integris nec granulosis nec 
postice divergentibus, manibus brevibus; pedum pari tertio longiori, femoribus infra 
leevibus. 
Nore. This species comes very near to the Cleistotoma Leachii of Milne Edwards ; but 
differs from it in the surface being altogether smooth. The length is four lines. 
Fam. OCYPODID, Leach. 
Sub-genus. Ocypope, Fab. 
Sp. 18. ( 

) Ocypode cordimana, Lat. 
Ocypode cordimana, M. B. Hist. Nat. des Crust. vol. ii. p. 48. 
Nore. The Ocypode cordimana of Dehaan appears to be a very different species. 
Sub-genus. CeratopuTHaLMA, Dehaan. 

Sp. 19. ( ) Ceratophthalma cursor, Herbst. 
; Cancer cursor, Herbst. vol. i. tab. 1. fig. 8 and 9. 
Sub-genus. GeLasimus, Lat. 
Sp. 20. ( ) Gelasimus chlorophthalmus, M. E. 

Gelasimus chlorophthalmus, M. E. His. Nat. des ‘Crust. vol. ii. p. 54. 
