50 TRACHELIPODA. YERMETUs. 
sisting of three or four volutions, imbricated above, smooth 
below; aperture of a round polygonal form ; umbilicus 
large ; penetrating to the apex of the shell. 
Euomphalus pentangularis. Plate V. fig. 1. Found in 
the Carboniferous Limestone of Ireland. 
The shells of this genus are entirely fossil, the species strongly resembling 
those of Delphinula; the volutions of which, however, increase in size more 
rapidly than in Euomphalus. They are met with in the Carboniferous Lime- 
stone, the Chalk, and Chalk Marl. 
Genus LV.— EULIMA.,. — Risso, 
Generic Character.—Shell elongated, pyramidal, smooth ; 
spire long, formed of numerous angulated volutions, termi- 
nating in an acute slightly tortuous apex ; aperture oval, 
anteriorly rounded, acute at the posterior union with the 
body volution; outer lip slightly thickened; columella 
smooth. 
Euiima labiosa. Plate VI. fig. 15. 
Found only in a fossil condition. 
Genus LVI. — CIRRUS. — Sowerby. 
Generic Character, — Shell spiral, conical, with a hollow 
fuamel-shaped axis; volutions contiguous, numerous, rounded, 
or slightly angulated. 
Cirrus depressus. Plate V. fig. 8. Found in the Chalk, 
Sussex. 
This genus consists entirely of fossil species, and are all nearly allied to 
Trochus, but may be distinguished by their funnel-shaped umbilicus. The 
species are chiefly met with in the Cretaceous and Oolitic groups of rocks. 
Genus LVII.— VERMETUS,. — Adanson. 
Generic Character.— Shell thin, tubulose, loosely spiral 
in the lower part, the three or four superior volutions 
regularly spiral; aperture orbicular, margins united, and 
provided with an operculum. 
Vermetus Bognorensis. Plate V. fig. 80. Found in the 
Sandstone rocks of Bognor, at Highgate, and Isle of 
Sheppy. 
The shells of this genus are marine, and adhere to extraneous bodies by the 
attenuated and pointed extremity of the spiral part. They are found in the 
warmer regions of the globe. In their external form they resemble Serpule,. 
Fossil species are met with in the Cretaceous and Oolitic groups of rocks, 
