OF MEROUI AND ITS ARCHIPELAGO. 



157 



was unknown (or at least not stated in the standard conchological 

 works), the sign t is added. By this the reader will arrive easily 

 at the following conclusions : — 



A. Terrestrial Mollusca : the greater number of the species are 

 either confined to the Tenasseriru coast or range only into the 

 next adjacent countries, as Pegu, Arakan, or the Malayan Penin- 

 sula. Only the small-sized Stenogyra gracilis is spread through- 

 out continental India and the Malayan Archipelago. 



B, C. Fluviatile and Submarine Mollusca : most of them are 

 wider spread, chiefly in the direction of Siaru and the Malayan 

 Archipelago, and are also found in Bengal ; but only few range 

 much further to the west. 



D. Marine Mollusca : a very considerable number of species 

 range westwards to the shores of Eastern Africa, even into the 

 Red Sea, and eastwards to the Polynesian islands, several south- 

 wards to Natal and to the subtropical parts of Australia, and 

 northwards to China and Southern Japan. Only one {Natica 

 unifasciata) is stated with tolerable certainty to live also on the 

 west coast of America; and very few {Octopus rugosus, Lima 

 squamosa, and Pholas striata) are known also as inhabitants of 

 the Atlantic ; among these are some which are liable to be spread 

 by currents and drift-wood. Several Oriental species, however, 

 are represented in the West Indies by species so nearly allied, 

 that even the specific discrimination remains doubtful (Littorina 

 scabra, L. intermedia, and L. angulifera, Planaxis pyramidalis 

 and P. sulcatus, and Asaphis deflorata) . 



List of Shells collected at Mergui and its Archipelago, 



A. TERRESTRIAL MOLLUSCA. 



OPEECULATA. 



1. Cyclophoeus aueantiacus, Schumacher. (Plate XIV. 

 figs. 1-6, and Plate XV. figs. 1-6.) 



A number of rather large-sized specimens of Cyclophorus have 

 been collected, which are very near to one another, but exhibit 

 some differences in the elevation of the spire, the width of 

 the umbilicus, and the colours of the peristome. They form 

 a nearly continuous chain from the flat widely-umbilicated C. 

 pernooilis, Gould, to the more turbinated narrowly-umbilicated 

 C. malayanus } Reeve ; so much so that I dare not venture to 



14* 



