270 CRUSTACEA. 



SUBFAMILY I. LUPINE. 

 GENUS SCYLLA, De Saan. 



Scylla of De Haan (Faun. Japon., p. 11), corresponds to the first 

 section of the genus Lupa in Milne Edwards's Crustaces, i. 448. 



SCYLLA TRANQUEBARICA (Fair.) 

 Singapore. 



Ratio of length of carapax, 1 : 1'46 to 1 : T5. Medial region but 

 faintly indicated. 



Portumis tranquebaricus, FABRICIUS, Suppl., 366. 



Portunus serratus, RuFPELL, Krabben des rothen Meeres, p. 10, pi. 2, f. 1. 



Lupa tranquebarica, EDWARDS, Crust., i. 448. 



Scylla serrata, DE HAAN, Crust. Fauna Japonica, 44; KRATJSS, Sudaf. Crust., 25. 



Var. ? oceanica (Plate 16, figs. 6 a, b, natural size). A specimen 

 closely resembling the $ tranquebarica, if not identical with it, was 

 obtained at the Navigator Islands. It has the median emargination 

 of the front narrower and deeper than the next either side ; the 

 median region of the carapax a little more distinct than in the tran- 

 quebarica ; male abdomen oblong triangular, its sides from near the 

 base of the third joint to the apex very straight, instead of sinuous as 

 represented by Riippell. 



The length of the carapax is two inches and seven lines ; greatest 

 breadth, three inches and ten lines; ratio of length to breadth, 1 : 1-48. 

 There is also from the same islands, in our collections, a carapax of a 

 larger specimen, measuring four inches and eight lines in length, and 

 breadth, six inches ten and a half lines; ratio of length to breadth, 

 1:1-47. 



GENUS LUPA. 

 De Haan, in his changes, restricted the name Lupa to the single 



