156 CRETACEOUS GASTROPODA 
XXXIX.—RAPANA, Schumacher, 1817. 
(Probably including Corattiopuita, Adams). 
Char. Rapana, testa sub-pyriformi seu sub-globosa, crassa; spira brevi ; ultimo 
anfractu ventricoso, antice canali brevi atque recurvo producto; terminatione colu- 
mellart aperta. 
The distinction between Rapana and Rapa has been already referred to ; it lies 
principally in the length of the canal of the latter genus. Gray (Guide, 1857, p. 19) 
says that Rhizochilus, Steenstrup, is a Rapana that lives on Anthipathes, and at 
certain periods of its life closes its shell with a calcareous secretion, and permanently 
fixes itself to the coral, where it eventually dies. As the species, known under the 
name of Rhizochilus antipathicus, Steenst. possesses, however, even in the young state 
a prolonged canal, which it afterwards closes perfectly, it may be, we believe, correctly 
separated under a special generic name, but there appears to be rather a doubt as to 
those species which H. and A. Adams consider a sub-genus of Rhizochilus and call 
Coralliophila. If in other ways the animals of Coralliophila do not exhibit any 
particular distinction, I think they cannot be viewed as any thing else but Rapana 
of small size living on corals, as already stated by Dr. Gray. 
There is among our materials only one species, which we can refer to this genus ; 
it is small, but when compared with specimens of Rapa of equal size, the shell 
is at least twice as thick. It has all the principal characters of the genus. 
1—RAPANA TUBERCULOSA, Stoliczha. Pl. XIII, Fig. 6. 
Rap. testa globosa, crassa, spira brevissima ; ultimo anfractu ventricoso, costis 
numerosis spiralibus, tuberculatis, sulcis profundis angustisque separatis ornato ; 
apertura subrotundata, postice effusa ; labro ad marginem undulato ; labio calloso, pos- 
tice dentato, ad medium arcuato atque transversim rugoso, antice applanato et in- 
terne angulato ; columella ad terminationem excavata ; canali breviore, angustissimo, 
recurvo. 
Shell rather globose, consisting of about three volutions, the last of which 
envelopes the previous nearly completely, being strongly convex and inflated. The 
surface presents seven spiral ribs, provided with comparatively large tubercles and 
separated by narrow and deep sulci. The third rib from the suture is the strongest, 
forming a kind of keel. The aperture is roundish, posteriorly with a narrow canal ; 
the outer lip has an undulating, sharpened margin; the inner lip is very thick, 
posteriorly toothed, in the middle cross-wrinkled, anteriorly flattened and inter- 
nally angular. The canal is short, recurved towards the outer lip, opening in 
front with only anarrow slit. The columella is largely open and margined in 
front by the inner lip and backwards by the sharpened edge, which is produced 
by the anterior emargination of the canal. As regards ornamentation this 
species agrees markedly with Morea cancellaria, Conrad (Journ. Acad. Nat. 
Se. Phil. IV, p. 290, Pl. XLVI, Fig. 30), but it is much more semi-globose, 
