199 



i 



bears an unmistakable resemblance to "■ Pilumnoplax" sctdpta Stimpson ^), which in my 

 opinion should certainly be included into the genus Lophoplax. That it is not 

 identical with the present species is proved at once by the different sculpture : there are two 

 oblong, longitudinal protogastric lobes, instead of the oblique prominent ridges, in vStimpson's 

 species ; besides, the meropodites of the walking legs are considerably broader. In other respects 

 there is a remarkable agreement : the carapace, according to Stimpson, is also thickly pubescent, 

 the front deflexed, with a supra-marginal fringe of long hairs, the lateral margins are provided 

 "with five tuberculiform or paxilliform teeth"; the description of the chelae agrees nearly wholly 

 with that in the present new species, and "the grooves separating the posterior teeth of the 

 lateral margin are continued for a considerable distance upon the subbranchial region, passing 

 obliquely forward", precisely the same as in LopJioplax bicristata\ finally the ratio of the length 

 of the carapace to its greatest width is identical in both species (i : 1.27). 



Stimpson's species (9 only) was taken near Ousima (Japan). 



Dimensions in mm. : 



Distance between external orbital angles ... 4.6 



Breadth of front 2.4 



Greatest width of carapace (between tips of second epibranchial teeth) 6. — 



Length of carapace 4.75 



Subfam. Rhizopinae. 



This group has been first instituted by Stimpson -), and subsequently defined and enlarged 

 by MiERS, Ortmann and Alcock. It is to the diagnosis of the last named author ') that I may 

 particularly refer: the species of this subfamily are characterized by a nearly smooth carapace, 

 that is greatly vaulted longitudinally, by the fronto-orbital breadth befng narrow, by most 

 defectuous eyes and very often fixed eye-stalks, by the lateral margins of the carapace being 

 entire or nearly so (and never distinctly dentate), and greatly curving inward anteriorly towards 

 the eye-stalks, which are nearly level with the margins of the carapace, so that the orbit is 

 very shallow; the abdomen of the cf is usually much narrower than the sternum. This last 

 character has been always considered a safe characteristic of the Rhizopinae, in such a way, 

 that, for some years past. Miss Rathbun *) established a new subfamily, Typhlocarcinopsinae, 

 chiefly on account of the abdomen of the c? being greatly enlarged at the base, so that the 

 first segment exactly covers up the interspace between the bases of the posterior legs. Apart 

 from the fact, that in many genera of the Rhizopinae the first segment of the abdomen presents 

 a clear tendency to enlarge and to become broader than the third segment, I see no reason 

 to found a new subfamily, convenient as doing so perhaps may appear to the systematist, on 



1) Compare Smithson. Inst., Miscell. Coll., v. 49, 1907, p. 91, pi. II, f. 3. 



2) Pioc. Ac. Nat. Sc. Philadelphia, 1858, p. 95. 



3) Journ. As. Soc. Bengal, v. 69, prt 2, 1900, p. 287. 



4) K. Dansk. Vid. Selsk. Skr., 7. Raekke, Afd. 5, n" 4, 1910, p. 345. 



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