iç)i6.] Fauna of the Chilka Lake : Mollusca Gastropoda, etc. 353 



Diplodonta satparaënsis* Preston, 1915, p. 302, figs. 14, 14a, 14b. 



Dead shells of relatively large size were abundant in the inner part of the outer 

 channel at all times of the year. A few living specimens of smaller size were taken 

 in this channel in the salt-water season, and at the same season a few small living 

 individuals were found near Kalidai I. 



Diplodonta barhampurensis* Preston, 1915, p. 302, figs. 15, 15a. 

 P epresented onfy by a pair of empty valves (the type) taken in the inner part 

 of the outer channel in the freshwater season. 



Diplodonta (Felania) annandalei * Preston, 1914, p. 307, figs 20, 20a, 206 ; 1915, 



P- 303- 

 An abundant species at the inner end of the outer channel and also found in the 

 main area in the neighbourhood of Nalbano, off Patsahanipur, near Kalidai and at 

 Maludaikuda. As is the case with D. satparaënsis, living specimens were found only 

 in the salt-water season, while fresh but empty shells were obtained in fresh water 

 in September. 



Diplodonta (Felania) ovalis* Preston, 1914, p. 308, figs. 19, 19a, igb ; 1915, p. 303. 



A few individuals were found at Manikpatna and near the mouth of the lake, 

 while one was taken in the inner part of the channel near Barhampur I. No speci- 

 mens were obtained in the freshwater season. 



Diplodonta {Felania) chilkaënsis* Preston, 1914, p. 308, figs. 21, 21a, 21b; 1915, 



P- 303- 

 Except for one living specimen taken on the southern side of the Satpara penin- 

 sula, all our examples of this species, which are not numerous, were obtained towards 

 the seaward end of the outer channel on clean sandy ground. A single living indivi- 

 dual was found with a number of dead shells in September, 1913. Most of the shells 

 dredged in the freshwater season were dead. 



Family Psammobiidae, 



Psammobia mahosaënsis ,* Preston, 1915, p. 303, figs. 16, 16«, 16Ô. 

 This species is not uncommon in the inner part of the outer channel. Living 

 individuals were found in both the salt and the freshwater season. 



Family Solenidae, 

 In the Chilka Lake we found three forms of Solen that must be provisionally 

 regarded as distinct species, but we believe that until the anatomy of the Oriental 

 forms of the genus has been investigated, it will remain impossible to assign specific 

 limits with any degree of certainty. Our reason for making this statement is the fact 

 that in the collection of the Indian Museum, only a small proportion of which is named 

 so far as this genus is concerned, we find many forms that seem to grade one into 

 the other. Moreover at several localities on the Indian coasts pairs of forms occur, 

 resembling one another closely except in the proportions of their shell, the relative 

 dimensions being less different at some places than at others. Two forms of this 



