394 GASTEROPODA OF THE INFERIOR OOLITE. 



Pleurotomaria Dundriensis, Tawney. 

 — ■ distinguenda, Tawney. 



— scrobinula, Deslongchamps. 



— Athulia, d'Orbigny. 



— Alcyone, d'Orbigny. 



There is, perhaps, no sound palgeontological basis for this section, which may 

 include some incomplete forms more or less allied to species classed elsewhere. 



Section 3. — Sulcata (Leptomaria, Eugene Deslongchamps, in part). 



Shells small to middle-size, inclined to be heliciform, largely umbilicate. Spire 

 variable, often very convex, apex more or less depressed. The whorls have the 

 ornaments but slightly engraved, and are sometimes nearly smooth. Sinus-band 

 narrow, usually without spiral lines, and often sunken. The slit of the inner lip 

 extends some way back. 



Pleurotomaria sulcata, Sowerby. 



— — var. obconica, Tawney. 



— Ajax, d'Orbigny. 



— monticulus, Deslongchamps. 



— monticulo'ides, sp. nov. 



— sulcata- Hump hriesiana, sp. nov. 



— Amyntas, d'Orbigny. 



Section 4. — Fascia'ile. 



Shells conical, often of large habit, umbilicus moderate to nil. Whorls 

 convex or subangular, sutures distinct ; spiral ornament regular, but not very 

 deeply incised, decussated in the earlier whorls (decussato-striated) with a tendency 

 to smoothness in some cases. The sinus-band is almost exactly median and wide, 

 usually presenting a flat strap-like appearance, although in the earlier whorls the 

 spiral ornamentation may sometimes be noted. 



Pleurotomaria subplatyspira, d' rbigny . 



— fasciata, Sowerby. 



— Stoihlarti, Tawney. 



— amata, d'Orbigny. 

 transit is, d'Orbigny. 



— Alimena, d'Orbigny. 



Fasciata-gromp. 



