40 ' TRACHELIPODA. FUSUS. 
Triton, and that will be with those very few species, wherein the varices are 
more remote from each other than half a volution ; but attention to the other 
characters will lead to the distinction. 
The Ranelle are not numerous, and are natives of the East Indian Ocean. 
Fossil species are very rare, and hitherto have been found, principally, in 
the London Clay ; the Blue Marls of France; the Super Cretaceous rocks of 
Bordeaux, Dax, &c. 
SUBDIVISION II. 
Shells without a constant ridge on the outer lip. 
Genus XXXII. — PYRULA. — Lamarck. 
Generic Character. — Shell thin, pyriform, oblong, ven- 
tricose above, somewhat attenuated below, and usually very 
regular in form; spire short, rounded, and consisting of 
few volutions; aperture wide, terminating in an elongated, 
narrow, open canal, wider towards the aperture, and narrow- 
ing as it descends; outer lip thin, sharp on the margin, and 
minutely crenulated; columellar lip tortuous and smooth, 
and spreading over the front a thin enamel, which, in some 
instances, is hardly perceptible; outside generally cancel- 
lated, but entirely destitute of varices or umbilicus, and 
covered with an excessively thin epidermis. 
Pyrula nezilis. Plate LV. fig. 25. Found in the Lon- 
don Clay at Barton Cliff. 
The shells of this genus are few, and chiefly inhabit the Indian Ocean, as 
well as the coasts of South America. 
In a fossil state, the Pyrule are met with in the newer formations, namely, 
the London Clay, Blue Marls of France, and the Super Cretaceous rocks of 
Bordeaux and Dax, and Calcaire-grossier. 
Genus XX XIII. — FUSUS. — Lamarck. 
Generic Character. — Shell fusiform, or subfusiform ; 
spire usually turreted with many rounded volutions, and 
gradually acuminated, generally terminating in a pointed 
apex, although it is sometimes mamillary; for the most 
part, with longitudinal ribs and spiral grooves; aperture 
elliptical, ending in a lengthened straight canal; furnished 
with a horny operculum, having its nucleus at its acumi- 
nated lower extremity; outside covered by a rough epi- 
dermis. 
Fusus Parkinsonii. Plate III. fig. 30. Found in the 
Essex Crag. 
Fusus contrarius. Plate I. fig. 12. Found in the 
Suffolk Crag. 
