Melvill And standem : marine mollusca of madras. 31 



the present authors. (1) We should be inclined to estimate the probable 

 total of both Madras and Bombay marine mollusca, severally, as about 

 the same, say, 700 species or so. Both localities possess many 

 points in common. 



An asterisk (*) is appended to all those forms which are included in 

 the Bombay catalogue just alluded to. 



(I). DESCRIPTIONS OF NEW SPECIES. 



Cerithium carnaticum n. sp. (Plate I., fig. 1). 



C. testa attenuato fusiformi, solida, sordid} ochmcea, interdiwi 

 castaneo-variegata ; anfractibus ?wvem, ificequaliter varicosis, ad sitturas 

 superficialiter canaliculatis, longitudinaliter irregulariter cosiatis ; costis 

 rudibus, undique transversim rudi-liratis ; jundura costarum lirar- 

 umque scepe gemmulatis ; apertura ovata, labro extus effuso, pauilum 

 incrassato ; canali brevi. Long. 13, /at. 5 mm., sp. maj. 



It is curious that this Cerithium has not been described ere this, 

 for unnamed examples exist in the British Museum. Its affinities 

 would appear centred near C. adenense Sow. (which, however, is 

 much larger) and its allies. 



It is a rudely-sculptured species, solid, nine-whorled, attenuate, so 

 impressed at the sutures as to appear channelled ; the unequal varices 

 and the irregular longitudinal ribs are crossed by thick lirae, and at 

 the junction of these shining papillae occur. Mouth ovate, outer lip 

 effuse, a little thickened, canal short. 



Colina selecta n. sp. (Plate I., fig. 2). 



C. testa fusiformi, cylindrica, attenuata, solidiuscula, cinereo-brunnea ; 

 anfractibus undecim, apud suturas pauilum impressis, undique transversim 

 arete sulculosis ; sulci's impressopunctatis ; ultimo anfractu producto ; 

 apertura rotunda, labro exteriore effuso, incrassato, intus castaneo- 

 lineato. Long. 15, lat. 4 mm. 



Allied to C. pinguis A. Ad., the typical form of which is from the 

 Cape, while varieties occur in various tropical regions, e.g., Lifu and 

 the Paumotu Is. Our species resembles more C. tozniatum Sow., but 

 is not so pupiform in shape, nor is it noduled transversely. After exa- 

 mination of all forms of C. pinguis and allies, we have come to the 

 conclusion that this is distinct from any. It is an elegant shell, and of 

 marked peculiarity in appearance. 



Rissoina (Morchiella) thaumasia n. sp. (PI. I., fig. 3). 



R. testa fusiformi, versus apicem attenuata, solida, ochraceo-alba ; 

 anfractibus novem, turritis, apud suturas pauilum canaliculatis, septan 

 superioribus profundi decussatis; costis longitudinalibus prominentibus, 

 interstitiis quasi-punctatis ; anfractu penultimo et ultimo distinct e trans- 

 versim acutiliratis ; costis longitudinalibus fere evanidis ; apertura 

 obliqua ; labro exteriore multum incrassato. Long. 5, lat. 1*50 mm. 



1 Mem. Manchester Soc, ser. 4, vol. 7, p. 17-51, 1893. 



