THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE III. VOL. I. 



No. VI.— JUNE, 



I. — Contributions to the PALiEONTOLOGY of the Toekshike 



Oolites. 



By Wilfrid H. Hudleston, M.A., F.E.S., F.G.S. 



(Continued from Decade III. Vol. I. p. 204.) 



(PLATE VIII.) 



"Littorina" and Amberleya. 



THE group of shells figured on Plate VIII. (excepting Fig. 12, 

 whose position is doubtful) constitute a natural section of tur- 

 binate or trochiform species, which should be classed under one and 

 the same genus, or at most only separated subgenerically. They 

 are characterized, for the most part, by a conical spire, having a 

 rather wide angle ; are few whorled, separated by a widish suture, 

 and imperforate. The sculpture is rich, consisting of spiral bands 

 of more or less prominence, which sometimes constitute varices, 

 single or double, as the case may be. These spiral bands are usually 

 granulated or tuberculated, and are continued into the base of the 

 shell, which is convex and much produced. Between these spiral 

 bands is a fine system of axial (radial) lines or striae, sometimes 

 bifid, and probably forming crenulations in connection with the 

 more prominent spiral ornaments. 



The body- whorl exceeds in height the rest of the spire : aperture 

 very large and nearly circular. The outer lip follows the direction 

 of the angle of the shell with little or no curvature as far as the 

 posterior angle, which marks the termination of the most prominent 

 spiral : below this the margin of the aperture sweeps round in a 

 full curve towards the inner lip, which is slightly produced to meet 

 it.' The columella is slightly hollowed out, and has a moderate 



^ This producing of tlie pillar in the direction of the base causes a slight point, 

 ■which is held by Lycett to remove such a species as Turbo PhilUpsii from the 

 LittorifKB. If this be the case, then all the so-called Amberleyas must be placed in 

 the same category, and the general name of Turbo restored provisionally to the entire 

 group. There are existing species of Turbo possessed of an aperture in every 

 respect identical with that which is characteristic of the fossils now imder considera- 

 tion. Nevertheless, Hebert and Deslongchanips appear to have had no hesitation in 

 regarding the pointed extremity of the base as compatible with Litturina. (See their 

 description and figure of Littorina sulcata, op. cit. p. 65, pi. iii. fig. 3.) 



DECADE III. VOL. I. NO. VI. 16 



