CRUSTACEA DECAPODA OF THE INLE LAKE 



BASIN. 



By Stanley Kemp, B.A., Suqwriniendent, 

 Zoological Survey of India. 



Plates XXIV, XXV. 



Tlie collection of Decapod Crustacea made by Dr. Annandale and 

 Dr. F. H. Gravely in and near the Inle Lake in the Southern Shan States 

 comprises representatives of the following seven species : — 



POTAMONIDAE. 



Potamon {Potamoti) browneanum, sp. nov. 

 Potamon {Potamon) acanthicum, sp. nov. 

 Potamon (Potation) mrtohates, sp. nov. 



PaLAEMC'NIDAE. 



Palaemon naso, sp. nov., 

 Palaemon hendersoni, de Man. 



Atyidae. 



Caridina annandalei, sp. nov. 



Caridina weheri, prox. var. suwafrensis, de Man. 



That five of these species should prove to be undescribed is remark- 

 able, and particularly that three of the new forms should be Potamoni- 

 dae, for the Indian species of this family have been described by Alcock 

 from a great abundance of material, including the late Dr. John Ander- 

 son's collection from Upper Burma. 



The general results derived from an examination of the Decapod 

 fauna of the district agree with those obtained in other groups, especially 

 the Fishes and the MoUusca :— the fauna is in a large measure endemic 

 and, in consideration of the past history of the region (see the introduct- 

 ion to this volume, p. 6), must be regarded as including a large 

 proportion of peculiar species some of which once spread over a much 

 greater area. Like other groups of aquatic animals the Decapods of the 

 district appear for the most part to be specialized rather than primitive. 



Of the two prawns hitherto known, Palaemon hendersoni has a range 

 extending from the Darjiling district along the Eastern Himalayas to 

 Burma ; it is also abundant in the hills of Assam, south of the Brahma- 

 putra. The Burmese specimens differ slightly from those found in the 

 Himalavan regions and in Assam and possibly represent a distinct race. 

 De Man's Caridina weheri, described from Flores, Celebes and Saleyer 

 is represented in the Shan States by a form similar in some respects 

 to the var. sumatrensis from the east coast of Sumatra, but in all ))rob- 

 ability subspecifically distinct. Races of this species, some of which 

 undoubtedly deserve nominal recognition, occur over the whole of the 

 Indian Empire, but until it has been possible to make a detailed study 



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