336 CRUSTACEA. 



ten and two-thirds lines ; breadth, twelve and one-third lines ; ratio, 

 1:1-16; length of another male, twelve and three-fourths lines; 

 breadth, fourteen and one-tenth lines; ratio, 1:1*11. The colour is 

 dark or light brown, or brownish red, with the hand coarsely dotted 

 with colour. The median region is smooth, and shows its limits dis- 

 tinctly behind, and also on the front of the prsemedial areolet and the 

 front of the outer part of the extramedial, behind the eyes, but the 

 limit is very faintly discerned elsewhere ; the intramedial areolet is 

 not distinct except in its posterior outline. The front is slightly 

 impressed at middle. The tarsi have two sulci either side, and one 

 above, and the dorsal surface is scabrous, the lateral less so. 



P. nudus, Dana, Proc. Acad. Nat. Sci. Philad., 1851, v. 249. 



Genus TRICHOPUS, De Haan. 



Trichopus litteratus (Fair.), De Haan. 



Plate 20, fig. 8 a, male, natural size; h, abdomen and sternum. 



At sea, fifty miles southwest of west entrance of Straits of Suncla, 

 found on a floating piece of bamboo. 



Cancer litteratus, Fabr., Supp., 342 ; Herbst, iii. 58, pi. 48, f. 4. 

 Trichopus litteratus, De Haan, Faun. Japon., Crust., 32. 

 Varuna litterata, Edwards, Crustaces, ii. 95, pi. 14bis, f. 8. 



Genus GRAPSUS. 



In Grapsus, the sides of the carapax are arcuate, the surface more 

 or less lined transversely, the front shorter than half the breadth of 

 the body, and the tarsi spinulous below. The third joint of the outer 

 maxillipeds may be either oblong or as broad as long. 



Grapsus pictus, Latreille. 

 Plate 21, fig. 1, outer maxillipeds. 



