38 MR. E. J. MIERS ON CRUSTACEA FROM [Jan. 14, 



Platygrnpsus depressus, Stimpson, Proc. Ac. Nat. Sci. Phil. p. 

 104(1858). 



Two small specimens (male and female) are in the collection. 

 These differ from the description and figure of De Haan, and from 

 an adult male of P. depressus in the British-Museum collection, in 

 the existence of a small spine on the wrist at the antero-internal 

 angle ; and the posterior tooth of the lateral margins of the carapace 

 is obsolete in one, and very obscurely indicated in the other specimen. 

 The hands are slenderer, and the fingers straight and regularly 

 denticulated on their inner margins, whereas in the adult male the 

 fingers are arcuate and the upper has on its inner margin near the 

 base a large and prominent tooth. 



Matoya, 6J fathoms; lat. 34° 13' N., long. 136° 73' E., 48 fa- 

 thoms. 



This species is a common inhabitant of the Chinese and Japanese 



seas. 



The generic name instituted by De Haan, Platynotus, having 

 been previously employed, was changed by Stimpson to Platygrnpsus. 

 A second species, P. convexiusculus, described by Stimpson from 

 the Loo-Choo Islands, is scarcely sufficiently distinguished by the 

 characters given. 



The genus Platygrapsus is distinguishable from Heterograpsus 

 and other allied genera, with which it has affinities and which are 

 represented in the Japanese seas, by the form of the second and 

 third joints of the outer maxillipeds, which are obliquely articulated 

 with one another, whereas in those genera the margins along which 

 the articulation takes place are at right angles with the lateral 

 margins of the joints. 



Helice tridens. 



Ocypode {Helice) tridens, De Haan, Faun. Japon., Crust, pp. 28, 

 b7, pi. xi. fig. 2, and pi. xv. Hg. 6 (1835). 



Helice tridens, M.-Edw. Ann. Sci. Nat. (sfir. 3), Zool. xx. p. 

 189 (1853) ; Stimpson, Proc. Ac. Nat. Sci. Phil. p. 105 (1858). 



E. Japan, Yamada, lat. 39° 32' N., long. 141° 53' E., at depth of 

 7 fathoms ; bottom sandy, with broken shells. 



A single specimen, an adult female, in the collection. Length 1 

 inch, breadth nearly 1 inch 4 lines. 



This fine species was previously unrepresented in the British- 

 Museum collection. 



Leiolophus planissimus. 



Cancer planissimus, Herbst, Naturg. Krabben u. Krebse, iii. pi. 

 lix. fig. 3 (1804), 



Plagusia clavimana, Desm. Consid, Crust, p. 127, pi. xiv. fig 2 

 (1825) ; M.-Edw. Hist. Nat. Crust, ii. p. 92 (1837). 



Acanthopus planissimus, De Haan, Faun. Japon., Crust, p. 30 

 (1835). 



