Three New Species of Fresh-water ('nibs. 29 



dicated only by depressions in front of their normal position. Epibran- 

 chial tooth 7 mm. from the orbit, very broad, obtuse, its outer margin a 

 curve continuous with the curve from the tooth to the orbit, tooth bounded 

 anteriorly by a broad notch. Equidistant from this notch and from the 

 orbital angle and directly behind the latter is a deep transverse and some- 

 what triangular depression. 



Antero-lateral margin tuberculate; subbranchial region visible outside 

 the margin as a narrow rim. Front about one-fourth the width of the 

 carapace, margin nearly straight and not visible in a dorsal view ; the 

 median suture does not extend to the margin. Orbits oblique in a front 

 view (fig. 6), superior margin sinuous, directed outward and forward in a 

 dorsal view, outer angle prominent, acute. Inferior regions of the cara- 

 pace smooth, punctate ; subcervical groove very deep. In the abdomen of 

 the male (fig. 7) the sides of the sixth segment are oblique, of the seventh 

 sinuous. The merus of the outer maxilliped is broad, with regularly 

 rounded antero-lateral outline (fig. 8). 



Chelipeds very unequal. Merus with outer surface and upper and outer 

 margins somewhat rugose ; inner and lower surfaces and inner margin 

 smooth. Carpus slightly roughened, with a stout, triangular, blunt inner 

 tooth, below which is a low swelling ; anterior half marked by an irreg- 

 ular longitudinal depression. Larger hand very wide and thick, slightly 

 rough, the raised lines forming reticulating lines which are punctate, the 

 punctse connected by minute impressed lines ; space enclosed by the lines 

 of a darker color; fingers long; pollex bent at an angle of 45° with the 

 palm ; fingers gaping to the tips. Smaller hand punctate, almost smooth 

 and without conspicuous color marks ; fingers slightly bent and little 

 gaping. Ambulatory legs very long ; surface slightly rough ; merus 

 joints with entire margins ; carpal joints with a few spinules at the distal 

 extremity ; propodal joints with upper margins spinulous in the first and 

 fourth pairs, distal and lower margins more or less spinulous in all. 



Dimensions. — Male, length 48.5 mm., width 6o.3, width between mar- 

 gins 61.5, width of front below 14.2. 



Type, locality. — Loo Choo Islands; F. Sakamoto; one male (U. S. Nat. 

 Mus. No. 20642). 



This species comes nearest to P. (G.) transversus von Martens, but is so 

 different that they cannot be confused. The form of the abdomen and 

 legs alone sufficiently differentiates them. 



Potamon (Geothelphusa) macropus sp. nov. 

 PI. II, figs. 1-4. 



Postfrontal crest obsolete ; cervical suture present; epibranchial tooth acute; 

 ambulatory legs long and narrow. 



Carapace very convex antero-posteriorly, slightly so transversely ; 

 about one-third broader than long; branchial regions much swollen 

 laterally ; posterior width greater than exorbital width. The surface is 

 very finely granulate, and covered with small punctee visible to the naked 

 eye. The sutures of the carapace are shallow and the surface along their 



