ALVANTA DENSECOSTATA. 611 



Alvania densecostata (Etheridge and Bell, MS.). Plate LT, fig. 22. 



1893—98. liissoa densecostata, A. Bell, Proc. Roy. Irish Acad. [3J, vol. ii, p. 629, 1893; Trans. Eoy. 

 Geol. Soc. Cornwall, vol. xii, p. 152, 1898. 



Specific Chacncfos. — Shell solid, iniinite, elongato-tui-reted ; whorls convex; 

 ornamented by nniucrous fine, nearly strnight ribs, crowded closely together, 

 intersected by Sjnral striie which become stronger and more prominent below the 

 periphery. 



Dimension-'^. — -L. 3 mm. B, 1 mm. 



DlstriJ)iAtlo>i. — Not known living. 

 Fo.<<s!l : St. Erth. 



Remarlcs. — Mr. Bell informs me that this fossil is the same npon which his 

 It. densecoddtd Avas originally founded. It was then perfect, but unfortunately 

 the apex is now missing. 



Alvania Bellii, sp. nov. Plate LI, fig. 23. 



Specific G]inracfers. — Shell minute, solid, bvato-conical ; whorls 5, the last 

 ventricose, mucli the largest, three-fourths the total length, obtusely angulate at 

 the periphery and contracted below it; ornamented by strong and prominent 

 longitudinal ribs, which terminate suddenly on the body-whorl and are replaced 

 by well-marked spiral ridges with fairly wide interspaces, also by exceedingly fine 

 striae on the upper part of the shell ; spire short, rapidly diminishing upwards 

 towards a blunt and truncated apex ; suture well marked and somewhat channelled ; 

 mouth large in proportion, expanded, angulate above and rounded below ; outer 

 lip thin; lower part of the inner lip reflected on the columella, which is nearly 

 straight. 



JJimensions. — L. 2'5 mm. B. 1 mm. 



Distribution. — Recent : Not reported living. 

 Fossil : St. Erth. 



BemarJcs. — The fossil figured under this name is from the British Museum 

 where it has been labelled " li. clatlirdta,'' probably by an oversight — it is not 

 the R. clathrata of Philippi. As I cannot find anything else to which I can 

 satisfactorily refer it I dedicate it to my colleague, often named in this work, to 

 whom students of the St. Erth fauna are much indebted. 



Alvania curta (Dujardin). Plate LI, figs. 24, 25. 



1837. Rissoa carta, Dujardin, Mc'ni. Soc. Gc'ol. France, vol. ii, p. 279, pi. xix, fig. 5. 

 1856. Rissoa curta. Homes, Foss. Moll. Tert. Wien., vol. i, p. 571. pi. xlviii, fig. 15, 



