410 GASTEROPODA OF THE INFERIOR OOLITE. 



shape of the spire and, to a certain extent, the ornamentation connect it with the 

 Fasciatse. 



It is abundant and characteristic in the Irony Nodule-bed (Murchisonse-zone) 

 at Burton Bradstock. A smaller and more glabrous variety occurs in the 

 Concavus-bed at Bradford Abbas. Tawney quotes it from Dundry. All my 

 specimens indicate a fossil of the Lower Division. 



354. Pleurotomaria subplatyspira, d'Orbigny, 1850. Plate XXXVI, fig. 1. 



1850. Pleurotomaria subplatyspira, d'Orbigny. Prod., i, p. 269. 



1854. — — Terr. Jur., vol. ii, p. 496, 



pi. cccxciii, figs. 1 — 3. 

 Syn. — fasciata, var. platyspira, DeslongcJiamps. Vol. cit., 



p. 54, pi. vi, fig. 2. 



Bibliography, Sfc. — This and the three following species constitute the Fasciata- 

 group (Gyrocycla, Deslong., pars). 



Description. — A somewhat imperfect specimen from the Sauzei-bed, Milborne 

 Wick, is about 44 mm. in height and width, witli a spiral angle, slightly convex, of 

 64°. Shell umbilicate, rather obtuse at the apex. Whorls (nine) slightly convex ; 

 spirally striated in the anterior areas only, except in the extreme apical whorls, 

 where the ornaments are reticulate, as is usually the case with Pleurotomarisd 

 belonging to this section ; sutures distinct, but not deeply impressed. The sinus- 

 band is broad and slightly raised, showing but little trace of stride or growth-lines, 

 even in the earlier whorls ; it is flat and strap-like in the later ones, and antero- 

 mesial in position. The body-whorl is almost devoid of ornamentation. 



This specimen is slightly wider than the types of Deslongchamps and 

 d'Orbigny. The broad submesial sinus-band at once separates it from PI. 

 Amyntas and the whole of the " narrow-slit" section. 



355. Plei rotomaria fasciata, Sowerby, 1818. Plate XXXVI, fig. 3. 



L818. TROcnus fasciatus, Sowerby. Min. Conch., pi. ccxx, fig. 1. 

 1854. Pleurotomaria fasciata, Sowerby. Morris, Cat., p. 271. 

 1873. — — Tawney, Dundry Gasteropoda, p. 51 



(43). 



