Crustacea Decapoda and vStomatopoda. 
233 
Genus Pyxidognathus, A. Milne-Edwards. 
Pyxidognathus deianira, de Man. 
1888. Pyxidognathus deianira, de Man, Jo^lrn. Linn. Soc. Zool., XXII, p. 148, pi. x, figs. 4-6. 
Dr. Annandale obtained a single specimen of this scarce species among the roots 
of a dead palm trunk in the Patani River, below the town of Patani in the Siamese 
Malay States. The individual is a male with carapace 9 mm. in breadth. Except 
for the slightly more acute teeth on the antero-lateral margin of the carapace, the 
specimen bears the closest resemblance to two smaller males, co- types of the species, 
that are preserved in the Indian Museum. 
The species has hitherto been recorded only from Mergui, where it was obtained 
in mangrove swamps. 
Subfamily SESARMINAE. 
Genus Sesarma, Say. 
Sesarma quadratum (Pabricius). 
1887. Sesarma quadrata, de Man, Zool. Jahrh., Syst., II, p. 683, pi. xvii, fig. 2. 
1890. Sesarma quadrata, de Man, Notes Leyden Mus., XII, p. 99. 
1892. Sesarma quadrata, de Man, in Weber's Zool. Ergebn. Reise Niederl. Ost-Ind., II, p. 328. 
1895. Sesarma (Parasesarma) quadrata, de Man, Zool. Jahrb., Syst., IX, p. 182. 
1917. Sesarma [Parasesarma) plicata, Tesch, Zool. Meded. Mus. Leiden, III, p. 187 [syn.). 
Several specimens were found at dijfferent places in the outer lake of the Tale Sap 
(Kaw Keoh, Kaw Deng, Koh Yaw and Singgora) ; they were for the most part found 
under stones or running on the shore at some distance from the water. All appear 
to belong to the true S. quadratum as redefined by de Man. 
Sesarma haswclli, de Man. 
1888. Sesarma haswelli, de Man, Joiirn. Linn. Soc, XXII, p. 175. 
1917. Sesarma (Chiromantes) haswelli, Tesch, Zool. Meded. Mus. Leiden, III, p. 158. 
A single example of this species, an ovigerous female 16 mm. in breadth, was ob- 
tained by Dr. Annandale near Singgora. 
Alcock ' included 5. haswelli, along with 5. lividum, A. Milne-Edwards, and 5. 
dussumieri, Milne-Edwards, in his synonymy of S. bidens (de Haan), being evidently of 
the opinion that the five forms distinguished by de Man in 1888 in his " section C" 
[loc. cit., p. 175) were only based on individual variations of a single wide-spread 
species. De Man in 1902 ^ dissented from Alcock's opinion. 
In the Indian Museum are preserved the type of 5. haswelli, other specimens from 
Mergui originally determined by de Man as S. livida, a large number of examples 
examined by Alcock and several additional samples obtained in recent years. 
On examining this material I find little difficulty in separating it into groups, 
corresponding to those that de Man and Tesch recognize as distinct species. I have 
no doubt that Alcock formed a wrong estimate of the variability of the forms in- 
cluded in the hidens-gro\xp and that it will be necessary to subject the Indian material 
to a thorough revision. 
1 Alcock, Journ. Asiat. Soc. Bengal, I<XIX, p. 415. 
2 De Man, Abhandl. Senck. naturf. Ges., Frankfurt, XXV, p. 538 (1902). 
