CONCHOLOGY. 



47 



which the external pair are much smaller than the internal ; the 

 anterior contractile muscle larger than the other ; tubes very 

 distinct. 



Shell. Of a somewhat variable form, generally striated longi- 

 tudinally and much compressed, equivalved, more or less inequi- 

 lateral ; the anterior side almost always longer and more rounded 

 than the posterior, which constantly presents a flexuous fold, at 

 least at its inferior edge ; summits feebly marked ; hinge similar, 

 one or two cardinal teeth ; two lateral teeth, far apart with a pit 

 at their base in each valve ; ligament posterior, large ; round 

 muscular impressions. The finest species of this beautiful shell 

 are found in the pearl fisheries of Ceylon. Fifty-five species. 



Tellina unimaculata. 



T. virgata. 



T. semizonalis. 



T. staurella. 



T. lutirostra. 



T. rostrata. 



T. spengleri. 



T. radiata. 



T. crucigera. 



T. elliptica. 



T. albinella. 



T. rosea. 



T. foliacea. 



T. operculata. 



T. chloraleuca. 



T. remies. 



T. sulcata. 



T. crassa. 



T. exiUs. 



T. donacina. 



T. nitida. 



T. striatula. 



T. decussata. 



T. obliqua. 



T. nymphalis. 



Tellina margaritina. 



T. strigosa. 



T. planata. 



T. punicea. 



T. depressa. 



T. pulchella. 



T. fabula. 



T. tenuis. 



T. sulphurea. 



T. cornuta. 



T. irrisa. 



T. levigata. 



T. linquafelis. 



T. rugosa. 



T. lacunosa. 



T. gargadia. 



T. pristis. 



T. gigas. 



T. scalaris. 



T. psamotella. 



T. scobinata. 



T. brasiliana. 



T. umbonella. 



T. deltoidalis. 



T. multangula. 



