18G7.] Contributions to Indian Malacology. 53 



estuaries : Littorina melanostoma also occasionally occurs, but its home 

 is nearer the sea. 



Lower down where the creeks are broader, the belt of salt swamp 

 is narrower in general, and a broad shelving muddy shore succeeds, 

 the upper portion covered by a thick forest of Avicensia, while lower 

 down Nipa palms frequently occur. The beauty of the wide creeks is 

 greatly enhanced by the broad fringe of the bright green Avicensia, 

 over the tops of which the summits of hills, covered with dense green 

 forest, are frequently visible.* On the sloping muddy shore species 

 of Potamides, Assiininia, Amphibola, Plecotrc?na, Haminea, Stenothy ra ; 

 Area granosa, Nassa planicostata, and ColumheUa Duclosiana are to 

 be met with. On the stems of the Nipa and on the mangrove bushes 

 Neritina crepidularia and N. cornucopia, Littorina melanostoma and 

 L. scahra are found in abundance. 



I have only included in the present list those shells from the Bas- 

 sein river which are found above Negrais Island, for the reasons al- 

 ready stated. I regret that the list is not more perfect, and that I am 

 obliged to leave a few specimens undetermined. On the other hand 

 the majority have been carefully compared, and the names quoted 

 may, I think, in most cases, be relied upon. Immediately after 

 leaving Pegu, I was in England for a few months ; and owing to the 

 kindness of the late Mr. S. P. Woodward, of Mr. Arthur Adams, and 

 especially of the late Mr. Hugh Cuming, who allowed me to compare 

 my shells with the original types in his unrivalled cabinet, I was 

 enabled to determine, not merely my estuary collections, but also a 

 much more numerous series of marine species from the Arakan coast, 

 in a manner which would have been simply impossible in India. 



Unfortunately, during the years which have elapsed since these shells 

 were compared, a few have been mislaid or lost during constant tra- 

 velling in various parts of India. Still I hope that this list may have 

 some value as a contribution to our knowledge both of the geographi- 

 cal distribution and of the habitats of mollusca. Several of the. species 

 named, and some of the genera have, so far as I am aware, never before 



* So great is the height of the trees fringing the upper creeks, and so com- 

 pletely do they shut out all the surrounding country, that I was working amongst 

 them for several days in ignorance of the existence of hills nearly lUOO feet 

 high within 15 or 20 miles of me. 



