526 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



lateral margins. The cervical suture is sinuous, wider, and deflected 

 slightly backward in its inner half, becoming obsolete near the margin,- 

 and ending in a transverse depression. Lateral margin for the most 

 pait sliarply and irregularly denticulate, the denticles b<5Coniing smaller 

 and more obtuse anteriorly, where there is a shallow tooth b<;tween the 

 orbital angle and the cervical suture. Mj^dian sulcus well marked, (;ut 

 ting the superior frontal margin. Ei)igaKtric lobes faintly indicated. 

 Front (fig. 10, a) shallow, concave in a vertical din^ction; lower border 

 conspicuously marginate, sinuous, ihe front being dee|)eHt near the 

 middle; upper margin depressed, projecting forward in a tuberculate 

 crest, which is divided into two sliglitly convex lobes. The orbits are 

 of the same order as in dilatata, the lower margin sloi)ing downward 

 from the inner angle. The male abdominal appendages of the first 



segment ffig. 10, e, f) are of the same 

 <5lass as those of P. trintani and P. 

 tumimanuH ; of the two lobes on the 

 outer margin, the anterior is much 

 more thickened and deflexcd tlian in 

 those si)ecies; as in tristani, the pos- 

 terior lobe is reduced and subquad- 

 rate instead of triangular and acute. 

 The merus of the maxillii)eds (fig. 10, h) 

 is narrower than in tristani, its great- 

 est length exceeding its anterior 

 width. 1'he exrignath extends to the 

 distal third of the ischium of the 

 endognath. 



The chelipeds are distinguished bj 

 the slender, a<-uniinate carpal si)ine. 

 The propodus (fig. 10, c) is slightly 

 convex above and convex below the 

 palmar portion. The inner and upper surfaces are marked with small 

 tubercles, most abundant near the margins. The fingers do not gape, 

 and are tuberculate on both inner and outer surfaces. The ambula 

 tory legs are rather narrow. 



JHmemions. — Male: Length, 2.^ mm. ; width, 30.0 mm.; width of front 

 along lower margin, 9..5 mm.; greatest depth of front, 1.2 mm. 



Type. — No. 19483, U.S.N.M. ; one male received from the National 

 Museum of Costa liica. Palmar, Costa liica, 20 meters; George K. 

 Cherrie. 



Additional locality. — One male was also received from Mr. H. Pittier, 

 who collected it at Santo Domingo, Culf of Dulce, Costa Kica, April, 

 1890. 



PSEUDOTHELPHUSA PITTIERI, new species. 



Small species; superior marfjin of front keeled; carapace finely granu- 

 late; abdominal appendatjrs of the \<)\\}\ (jronp. 

 Carapace flattened, granulate anteriorly and laterally. Cervical 



FKI. 16.— PSEI'DOTIIELPIIUSACONVKXA, MALE. 

 O. ^n0^fT, NATfUAL BIZE. h. MaXII-UI'ED, 

 X 2. C. LahOEK f-HELA, NATUKAL 8I7,K. 

 (t. AllUOME.V, NATtJUAL SIZE. «. LEFT AB- 

 DOMINAL ai'I'E.vdage, innee view, X 3. 

 /. The same, lowee viewi, x 3. 



