1879.] THE COREAN AND JAPANESE SEAS. 39 



Leiolophus planissimus, Miers, Cat. New-Zeal. Crust, p. 46 (1876); 

 Ann. & Mag. Nat. Hist. (ser. 4) i. p. 153(1878) 



Four examples, a male and three females, without definite locality, 

 are in the collection. 



This species is very widely distributed, occurring both in the 

 Indo-Pacific and Atlantic Reigons. 



Carcinoplacid^. 

 Heteroplax? nitidus, sp. n. (Plate II. fig. 2.) 



Carapace smooth, glabrous and shining, subtrapezoidal, transverse, 

 its greatest breadth being at the level of the second lateral marginal 

 tooth ; in front of this the carapace and frontal region is obliquely 

 deflexed ; behind it the carapace is nearly flat, and the lateral margins 

 straight and slightly convergent to the straight posterior margin. 

 Lateral margins with two small teeth, including the outer orbital 

 tooth. Front about one third the breadth of the anterior margin of 

 the carapace, with the anterior margin straight. Eyes about 

 equalling the front. Antennae with the first joint about twice as long 

 as the second, which is small, occupying the hiatus between the 

 inner angle of the orbit and the frontal margin. Outer maxillipeds 

 with the third joint quadrate, and about half as long as the second 

 joint, which is smooth and longitudinally sulcated on its outer sur- 

 face ; exognath robust. 



Anterior legs (in the female) rather robust ; arm very short, smooth ; 

 wrist smooth externally, and with a small tubercle on its inner sur- 

 face: hand smooth, without tubercles or granules ; fingers straight and 

 acute, crossing at the tips when closed. Postabdomen of female 7- 

 jointed. Length 3 lines, breadth rather over 4 lines. Colour whitish ; 

 brownish pink on front of carapace. 



A single specimen, a female, was collected at a depth of 40 fathoms 

 in the Corean Straits, lat. 3.^ 40' N., long. 182° 55' E. 



I have some doubt whether this species should be referred to the 

 genus Heteroplax, which is only known to me by Stimpson's 

 diagnosis, according to which the basal antennal joint is longer and 

 occupies the orbital hiatus. The species in other respects appears 

 referable to the genus. The longitudinal ridges on the palate are 

 distinct. In this character and in the broader front and shorter eye- 

 peduncles it differs from Gonoplax, while Litocheira of Kinahan, 

 another allied form, has, on the contrary, much shorter eyes and 

 broader and less deflexed front than the species here described. 

 Specimens of the species L. bispinosa, on which the last-mentioned 

 genus was founded, are in the British-Museum collection from 

 Australia ; and in these the longitudinal palatal ridges are distinctly 

 marked. Kinahan, however, in his description says that they do not 

 exist. 



