Crustacea Decapoda and Stomatopoda. 223 



forty-seven forms being represented. At the mouth of the Patalung river and in 

 the inner of the two lakes of which the Tale Sap is composed, the water was fresh 

 at the time when the collection was made and probably remains so throughout the 

 year. In the channel between the two lakes and in the outer lake it was brackish, 

 specific gravities falling between 1-0015 and 1-0085.' 



The following species were obtained in these two regions : — 



Patalung River and inner lake of Tale Sap. 



Fresh water. 



Paratelphtisa (Paratelphusa) germaini Palaemon elegans, de Man. 



(Rathbun). Caridina propinqua, de Man. 



Palaemon carcinus, Fabricius. „ gracillima, Lanchester. 



„ lanchesteri, de Man. „ nilotica, subsp. macrophora, nov. 



Outer lake of Tale Sap and channel between lakes. 



Brackish water. 



Rhynchoplax exiguus, Kemp. Dorippe astuta, Fabricius. 



Gelasimus annulipes, Latreille. Clibanarius longif arsis (de Haan). 



Dotilla wichmanni, de Man. Diogenes avarus, Heller. 



Camptandrium sexdentatum, Stimpson. Upogebia {Upogehia) heterocheir , Kemp. 



Grapsus strigosus (Herbst). Palaemon carcinus, Fabricius. 

 Metopograpsusmessor ÇBorskM). ,, sM^iaz'cMS (Heller), de Man. 



,, macM/a^î^s, Milne- Edwards. Alpheus paludicola, Kemp. 



Varuna litterata (Fabricius). Caridina propinqua, de Man. 

 Sesarma quadratum (Fabricius). ,, gracillima, Lanchester. 



,, haswelli, de Man. Penaeus indicus, var. merguiensis, de Man. 



„ taeniolatum, White. „ carinatus, Dana. 



„ siamense, Rathbun. Penaeopsis monoceros (Fabricius). 

 Pilumnus quadridentatus, de Man. „ a^ws (Milne- Edwards) . 



Scylla serrata (Forskâl). „ hrevicornis (Milne-Edwards). 



Neptunus pelagicus (Linn.). Acetes indicus, Milne- Edwards. 

 Charybdis crucifera (A. Milne- Edwards) . ,, japonicus, Kishinouye. 



,, affinis, Dana. Lucifer hanseni, Nobih. 



„ callianassa (Herbst). Squilla scorpio, Latreille. 

 Ebalia heterochalaza, sp. nov. ,^ ^^ var. immaculata, Kemp. 



Philyra sexangula, Alcock. ^, nepa, Latreille (Bigelow). 



„ olivacea, Rathbun. ,, interrupta, Kemp. 



Squilla raphidea, Fabricius. 



It is probable that a considerable number of the brackish-water forms are merely 

 casual or seasonal immigrants to the lake and do not inhabit it permanently ; the fact 



I Nearly all the species were found in water the specific gravity of which varied from i'0O3S to 1-0085 (corrected). 



