49 



The "Siboga" collected, besides one already known species, another, that is appar- 

 ently new. 



Key to the species : 



1 . Tympana on meropodites of walking legs present .... 2 

 Tympana on meropodites of walking legs absent .... 5 



2. Upper orbital margin transverse, not sloping. Lateral borders 



of carapace arcuate, convex-, carapace itself with short, 



transverse, setiferous rugosities T. dcschaiiipsi Rathbun ^) 



Upper orbital margin much sloping backward. Lateral borders 

 of carapace concave or straight, but markedly converging 

 backward ; carapace itself nearly smooth 3 



3. Eye-stalk continued beyond the cornea into a long, cylindrical 



horn, somewhat resembling that of Ocypoda ccratophthalma 



(Pallas). A tooth behind e.Kternal orbital angle .... T. ceratopJioj'us (Koelbel) 

 Eye-stalk not continued beyond the cornea 4 



4. External orbital angle produced, defined posteriorly by an 



emargination. Both fingers of chela longitudinally carinate. 



Abdomen of cT not constricted in the middle T. pusillus (de Haan) -) 



External orbital angle directed forward, not followed posteriorly 

 by an emargination. Fingers of chela not carinate. Abdomen 



of cT constricted in the middle T. intes:er n. s 



i> ' 



sp. 



5. Lateral margins of carapace diverging backward. Carpopodite 



of cheliped much elongate, with an obtuse prominence near 

 proximal end of inner margin, meropodite very short, scarcely 



projecting beyond carapace T. oj'ientalis (de Man) '^) 



Lateral margins of carapace subparallel (convex) or converging 

 backward. Carpopodite of cheliped of ordinary shape and 

 unarmed 6 



6. Upper orbital margin transverse. Palm of chela with a reticul- 



ating pattern, immovable finger on a level with lower border 



of palm. Walking legs short and rather thick T. stapletoni de Man ■*) 



Upper orbital margin sloping. Palm of chela granular, not 

 reticulate, immovable finger bent downward. Walking legs 

 long and narrow T. pJiilippinensis Rathbun 



1) Proc. U.S. Nat. Mus., v. 46, 1914, p. 356, pi. 32, pi. 33, f. i. It has been recorded from Shanghai and Korea. Notwith- 

 standing the tympana on the legs, save the last pair, this species exhibits an unmistakable resemblance to T. stapletoni de Man, but 

 the front is rounded, not angled, the palm has a longitudinal ridge close to and parallel with the under border, and the shape of the 

 abdomen of the (;^ is somewhat different (R.\thbun). 



2) Ocypode (Cleistostoma) pusilla de Haan. Faun. Japon., 1S35, p. 56, pi. 16, f. I. Hab. Japan. 



3) Dioxippe oricnialis de Man. Journ. Linn. Soc. London, v. 22, 18S8, p. 138, pi. 9, f. 8 — to. Hab. Mergul .\rch. 



4) Rec. ind. Museum, v. 2, prt 3, 1908, p. 212, pi. 18, f. i. In brackish water of the Dacca District (Eastern Bengal). 



5) Proc. U.S. Nat. Mus., v. 47, 1914, p. 84. Hab. Philippines. 



49 



SIIiOGA-ENPEDlTlE XXXIX c". 7 



