80 PROCEEDINGS^ OF THE NATIONAL MUSEUM. vol.47. 



Legs long and narrow, the third pair more than twice as long as 

 the carapace, and its menis two and one-third times as long as wide. 

 The spine on the upper margin of the merus- joints is acuminate. The 

 propodites are unusually long, the anterior margin of the third one 

 being 4 times as long as its greatest width; the dactyls, on the other 

 hand, are rather short, that of the third leg about two-fifths as long 

 as the propodus. The dactyli are of uncommon form, convex on 

 the anterior margin and also, but very slightly so, on the posterior 

 margin, down to the long-pointed tip. 



This species has no resemblance to any other of the subgenus 

 Holometopus, but its general aspect is much like that of a Samoan 

 species of the subgenus Parasesarma, which I shall describe later. 



SESARMA (PARASESARMA) DUMACENSE, new species. 



^7/2>e-ZocaZ^fy.—Dumaca River, Luzon; February 25, 1909; 1 female, 

 thin-shelled. 



Type.— C^t. No. 45922, U.S.N.M. 



Dimensions. — Type female, length of carapace 13.2 mm., width 

 between antero-lateral angles 17.6 mm., width between postero- 

 lateral angles 15.7 mm., width of front 9.8 mm., length of propodus 

 of cheUped below 7.9 mm., same above 3 mm., height of same 3.4 mm., 

 length of merus of second leg 10.7 mm., width of same 4.8 mm. 



Allied to S. plicatum} The sides of the carapace are slightly con- 

 cave; the antero-lateral tooth is acute; its outer margin does not 

 curve inward toward the tip as in S. plicatum, but the tooth projects 

 strongly outward. The interregional grooves are very deep, as are 

 also the grooves separatmg the postfrontal lobes; these grooves are 

 continued back nearly to the angles of the mesogastric region. On 

 each branchial region there is a smooth longitudinally obhque ridge 

 running near the side of the cardiac and intestinal regions. The 

 lateral margins of the deflexed front converge below, while in iMcatum 

 they diverge; that part of the front lying before the antennules is 

 very swollen. The propodus of the cheliped is more slender than in 

 the female of iMcatum; on the upper surface of the palm there is a 

 pectinated ridge beginning at the distal inner angle of that surface 

 and running in a longitudinally obhque direction, not in a trans- 

 versely oblique direction, as in 'plicatum, parallel to this ridge there 

 is a fine granulated ridge near the posterior margin. The protuber- 

 ances on the upper margin of the movable finger are low and scalari- 

 form; there are about 7 on the proximal half, after that they become 

 very faint; each one is divided by a transverse line into a large 

 proximal portion and a small tubercuhform distal portion. The 

 anterior or upper margin of the meropodites of the ambulatory legs 



1 (Latreille) Rathbun, Kgl. Danske Vidensk. Selsk. Skrifter, 7 Raekke, naturv. og math. Afd., vol. 4, 

 1910, p. 329, and synonymy. 



