GASTEROPODA. 27 



the form of the aperture, which more resembles that of those species from the Lower 

 Tertiaries (such as Turritella sulcata and others) which were placed in a new genus pro- 

 posed by Dr. Gray, 1840, and called Mesalia. 



The engraver has in the figure shown the specimen in too perfect preservation, for the 

 striations on the upper whorls are, in the specimen itself, obliterated, as are those also 

 along the central portion of the lower whorls, and the aperture also is less perfect than 

 represented. 



Turritella Taurinensis (?), Miclielotti. 2nd Sup., Tab. II, fig. 19. 



Turritella Taurinensis, Mich. Etud. Mioc. Inf., p. 84, pi. x, figs. 1, 2. 



Locality. Red Crag, Sutton. 



This imperfect specimen of some species of the genus Turritella has been in my 

 possession for some years. The genus is one in which the determination of a species is 

 most difficult from the great variation which individuals belonging undoubtedly to one 

 species, such as those of Turritella incrassata, present, and out of which variation several 

 species have been made. The present specimen seems, however, to differ so much that I 

 think it must be distinct from any of the forms of incrassata. There is a difference in 

 the thread-like arrangement of the stria?, and a greater convexity in the volutions, than 

 in either incrassata or terebra. A shell described by Dr. Speyer, under the name of 

 Turritella Geinitsii, Cassel, ' Tert. Conch.,' p. 145, tab. xx, figs. 8 — 12, is not unlike 

 the one now figured, and I have little doubt that our present specimen is a derivative 

 in the Reel Crag from some bed older than the Coralline Crag. Pigs. 16 and 17, Tab. II, 

 represent varieties of T. incrassata, which may, I think, be referred to T. acutangulata 

 and T. subangulata, Brocchi. 



Eulima Natjmanni ? von Konen. 2nd Sup., Tab. IV, fig. 22. 



Eulima Naumanni, von Konen. Marine Mittel. Oligoc, t. xi, fig. 19. 



— Speyer. Cassel. Tert. Conch., p. 202, taf. xxvi, figs. 12, 13, a, b. 



Axis -j^ths of an inch. 



Locality. Cor. Crag, Sutton. 



A single specimen in my cabinet differs so much from any of the species of Eulima 

 known from the Crag that I have referred it provisionally as above, depending upon the 

 representation of the species given in the works of Speyer, and von Konen. So many 

 so-called species in this genus present such trifling differences that before a correct determi- 

 nation can be made it will be necessary closely to compare the specimens themselves^ 



