ODOST()]\rrA DENSA. GOl 



1905. Ptychostniiion jxiIHiidi. K(>l)elt, Icou. schalentrag. europ. Meeresconcli . , vol. iii, ]>. 79. [)1. Ixvi, 



fi^s. 16, 17. 

 1SM4. Odosfoiiilii jKilita, CeniUi-TiTlli, Palaconl. Kal., vol. x\, p. 254, pi. .xxii, fig.s. 28 — 32. 



Specific (^Inirdcler.s. — Shell moderately larov, solid, obloiio-o-coiiical ; wliorls 

 8, nearly flat, oi-adually ;iiid regulai'ly enlarging, the last rounded, not angulatc, 

 about half the total length ; suture slight, not channelled ; mouth short, oval ; 

 outer lip conti-acted at the periphery or just below it; nsnally grooved inside; 

 i]iner lip adhering to the pillar above the tooth ; tooth conspicnons, placed just 

 behind the umbilicus. 



Dimensions. — L. 5 — 7 mm. B. 2*5 — 3 mm. 



Distribution. — Recent : Isle of Man, Scotland, from the Clyde district to the 

 Hebrides. A smaller variety has a more southern range. 



Fossil: St. Erth. Coralline Crag: Sutton, Gedgrave, Boyton. 

 Waltonian : Walton-on-Naze. Butleyan : Butley (A. Bell). Holocene : Portrush. 



lleinarhs. — I retain the division between 0. conoidca and 0. pollta with many 

 apologies to my good friend M. Dautzenberg, who seems inclined to regard all the 

 English fossil specimens of E. conoidea I have submitted to him as belonging to 

 the latter species, Avhile the Marchese di Monterosato considers the one a littoral 

 variety of the other. Apparently they are both variable forms. The name 

 0. conoidea is better known to students of the Crag than is 0. polita. For the 

 present, at least, I think it may be desirable, especially for the sake of those who 

 rnay have occasion to consult the lists of fossils issued during many past years, to 

 retain the old nomenclature. I prefer also to continue the use of the old generic 

 term Odostomla rather than of Odoiitostomia, as recently proposed. 



Odostomia densa, sp. nov. Plate L, fig. 32. 



Specific Characters. — Shell small, solid ; whorls 6, slightly convex, the last 

 rather more than half the total length ; spire short, subcylindrical, gradually 

 increasing upwards to a blunt, compressed point; suture slight; mouth small, 

 ovate, angulate above, rounded below ; inner lip with a prominent, projecting 

 tooth ; base rounded. 



Dimensions. — L. 5 mm. B. 2 mm. 



Distribution. — Not known living. 



Fossil : Newbournian Crag : Waldringfield. 



BemarJcs. — The specimen here figured was sent to Mr. Bell by Mr. A. S. 

 Kennard who had obtained it at Waldringfield. As we cannot find any recorded 

 species of Odostomia to which it can be satisfactorily referred, I adopt the specific 

 name densa for it, in accordance with Mr. Bell's suggestion. 



