Rathbun — New Crabs from Gulf of Siam. 109 



Family GRAPSIDyE. 



SUHFAMII.Y VARrXIN.E. 



Camptandrium paludicola sjj. nov. 



T_i/pe. — 9 , mangrove swamp, Lem Ngob. 



Dimensions. — Length, 4.3 mm. ; width, 5.3 mm. 



Surface uneven, regions ornamented with a few tubercles regularly 

 placed. "Width of front K greatest width of carapace. Three large 

 antero-lateral teeth, and a minute tooth behind the last. Chelipeds sub- 

 cylindrical, subterminal spine on arm. Fingers as long as palm, l)roadly 

 hollowed at tips. Merus joints of legs dilated, a triangular spine on dis- 

 tal third of anterior border. 



Acmaeopleura rotunda sp. nov. 



Type. — d, south of Koh Kut, 17-20 fathoms, mud. 



Dimensions. — Length 2 mm.; width 1.75 mm.; fronto-orbital width, 

 1.7 mm. ; width of front, 0.7 mm. 



Carapace snbcircular, widest at middle ; front bilobed ; eyes stout, fill- 

 ing orbits. Maxillipeds not gaping, merus and ischium subequal to each 

 other in length and width, but much wider than long; exognath narrow. 

 Legs narrow, unarmed, dactyli very slender, moderately curved. 



SuBFA>nLY SESARMIN^. 



Sesarma (Chiromantes) siamense sp. nov. 



Type. — 9 , Koh Kut, stony coast. 



Dimensions. — Length, S.5 mm.; anterior width, 9.5 mm.; posterior 

 width, 9.7 mm. ; width of front, 5.1 mm. 



Lateral tooth slight, obtuse-angled. Middle pair of superior lobes of 

 front distinctly wider than outer pair. A slight obtusangular expansion 

 on anterior margin of arm. Palm striated on upper surface, 2 strise 

 sharply marked, 5 or 6 spinules on upper edge of dactylus on proximal 

 f. A sharp subdistal spine on merus-joints of legs, last three joints 

 sparsely furnished with long fine hairs. 



Family PINNOTHERID^. 

 Subfamily PINNOTHERIN.^. 

 Pinnotheres biirgeri sp. nov. 

 Type.— ^ , Koh Kram, 30 fathoms. 

 Dimensions. — Length, 2 mm. ; width, 2 mm. 



Near P. gracilis Burger. Carapace nearly circular, front little advanced, 

 orbits cut out of margin, eyes un pigmented. Chelipeds with lower mar- 

 gin of propodus concave below distal end of i>a]m ; fingers tapering pretty 

 regularly to the strongly curved tips; a slight basal prominence on each 

 finger. 



Pinnotheres lanensis sp. nov. 

 Type. — 9 , Koh Lan, 30 fathoms, mud. 

 Dimensions.— Length, 2.4 mm.; width, 2.7 mm. 

 Allied to P. parvitlus Stimpson. Carapace very thin, with an antero- 



