748 MR. W. F. LAN CHESTER ON CRUSTACEANS [June 19, 



there is another small tooth between the first two spines, and 

 an even smaller one between the second and third. Dr. de Man 

 (Mergui, Crust. 1. c.) says : " The outer and upper surfaces of the 

 hands of G. affine are covered with short hairs, whereas in the 

 specimen of G. crudferum " (i. e. the only one obtained from the 

 Mergui Archipelago) " their surfaces are perfectly glabrous and 

 smooth." In this example of G. affine, their surfaces are nearly 

 smooth in the case of the left chelipede, which is smaller than 

 the right : the carpi are in both cases externally hairy. 

 Dim. 35x24. 



XL. Genus Sctlla de Haan. 



65. Sctlla serrata Forskal. 



Cancer serratus, Forskll, Descr. Anim. p. 90 (1775). 



Cancer olivacens, Herbst, Naturgesch. d. Krab. ii. p. 157, pi. 

 xxxviii. f. 3 (1794). 



Portunus tranquebaricus, Fabr. Suppl. Ent. Syst. p. 366 (1798). 



Lupea tranquebarica, M.-Edw. Hist. Nat. Crust, t. i. p. 448 

 (1834). 



Portumis (Scylla) serratus, de Haan, Crust. Japon. p. 44 (1839). 



Scylla serrata, A. M.-Edw. Arch. Mus. t. x. p. 349 (1861) ; 

 Hasw. Cat. Austr. Crust, p. 79 (3 882) ; Henderson, Trans. Linn. 

 Soc., Zool. vol. v. p. 372 (1893). 



Hab. Singapore ; one large male, caught in the fishing-stakes 

 used by the natives, about 3-6 fms. 



Dim. 152x102. 



XLI. Genus Thalamita Latr. 



66. Thalamita chenata Latr. 



Portunus crenatus, Latr. Coll. du Museum. 



Thalamita crenata, Kiipp. Krab. d. rothen Meeres, pi. (!, pi. i. 

 f. 2 (1830); M.-Edw. Hist. Nat. Crust, t. i. p. 461 (1834). 



Thalamita prymna, var. crenata, Kossmann, Zoolog. Ergebn., 

 Malacostraca, p. 48 (1877). 



Thalamita crenata, de Man, Mergui Crust, p. 79 (1888). 



Hab. Singapore; from the nets of native fishermen. Three 

 females. 1 note the following variations : — 



Specimen A. The 4th antero-lateral tooth on the left side is only 

 represented by a prolongation of the posterior edge of the tooth 

 in front ; thus forming one enormous tooth, completely filling the 

 normal positions of the 3rd and 4th teeth. Eight side normal. 

 Posterior border of penultimate joint of last legs dentate. 



Specimen B. Normal, except for denticulation of the posterior 

 border of the penultimate joint of the last legs. 



Specimen C. Penultimate joint of last legs denticulate ; cara- 

 pace, chelipedes, and posterior surface of last legs thickly covered 

 with short hairs. 



Dim. 2 67x44. ? 60x39-5. $ 53x35*5. 



