Crustacea Decapoda and Stomatopoda. 
227 
Rhynchoplax exiguus, Kemp. 
1917. Rhynchoplax exiguus, Kemp, Rec. Ind. Mus., XIII, p 260, fig. 10. 
A very small species without any strongly marked characteristics. Ten specimens 
were found by Dr. Annandale in the outer part of the Tale Sap, on the mainland 
opposite the western end of Koh Yaw. They were living in lumps of turf that had 
fallen into the lake owing to the undermining of the banks. The specific gravity of 
the water was about 1-00625. 
Family OCYPODIDAE. 
Subfamily OCYPODINAE. 
Genus Gelasimus, Latreille. 
Gelasimus annulipes, Latreille (Milne-Edwards). 
1900. Gelasimus annulipes, Alcock, Journ. Asiat. Soc. Bengal, LXIX, p. 353. 
1915. Gelasimus annulipes, Kemp, Mem. Ind. Mus., V, p. 221. 
A colony of this abundant species was found by Dr. Annandale at Kaw Deng at 
the mouth of the Tale Sap. The claws of large males were of a pale dull yellow colour 
in life. No specimens were ob.served more than a few hundred yards within the mouth 
of the lake, the water being practically as salt as that of the Gulf of Siam. 
Subfamily SCOPIMERINAE. 
Genus Dotiila, Stimpson. 
Dotilla wichmanni, de Man. 
1892. Dotilla wichmanni, de M.a.n, in Wsher's Zool. Ergebn. Reise Niederland. Osl-Ind., II, 
p. 308, pi. xviii, fig. 8. 
1895. Dotilla wichmanni, de Man, Zool. Jahrb., Syst., VIII, p. 577. 
1910 Dotilla wichmanni, Rathbun, Dansk. Vid. Selsk. Skrift. (7), Naiurvid. og Math., V, p. 324. 
1918. Dotilla wichmanni, Tesch, Decap. Brachyur. ' Siboga' -Exped., I, p. 45. 
A large number of specimens were obtained at Kaw Deng at the mouth of the 
Tale Sap on the opposite side of the channel from Singgora. 
The series includes some very fine individuals with carapace nearly 8 mm. in 
length and consequently much larger than any of de Man's original spe^iimens, none 
of which exceeded 5 mm. In males between 6 and 8 mm. in length the carapace bears 
three large angular projections on either side ; two of these are situated, one behind 
the other, on the outer side of the deep groove that borders the lateral margin, while 
the third, which is more spinose in character and possesses a corneous apex is situated 
on the side-wall, immediately beneath the small tooth that defines the upper and outer 
limit of the orbit (text-fig. i). These projections are not sefen in females or small 
males. 
In large males, also, there is a short but high ridge on the inner face of the carpus, 
situated close to the meral articulation and easily visible in dorsal view. There is no 
