VoLVA. MOLLUSCA. SOLENOSTOMATA. 
331 
Length about |ths of an inch ; breadth |ths ; of a pink colour with or 
without ( C. arctica ) dark dorsal spots ; striae distinct, bifurcated at the sides. 
In the young state, the shell is smooth, except some appearances of striae on 
the inner-lip, and the apex exhibits two or three whorls, — in which state it 
is the C. buUata of Mont. Test. Brit. 202. t. vi. f. 1. The C. pediculus dif- 
fers from the present species, with which it has been frequently confounded, 
by the roughness of the striae, and the presence of a longitudinal dorsal 
groove. 
EXTINCT SPECIES. 
1. C. oviformis. — Egg-shapped, tumid, smooth, slightly marginate ; aperture 
widest at the lowest end, left side of the aperture obscurely toothed ; right 
lip involute, tumid.— jS'ower. Min. Conch, t. iv. — London Clay. 
2. C. cocciweWoicfes.— Ovate 'sphaeroidal, transversely striated; striae nu- 
merous, acute, not interrupted ; aperture slightly arched, not contracted in 
the middle. — Sower. Min. Conch, t. ccclxxviii. f. 1. — Suffolk Crag. 
3. C. retusa. — Obovate, sphaeroidal, transversely striated ; striae elevated, 
uninterrupted, few, remote ; aperture a little curved at the narrowest end. 
— Min. Conch, t. ccclxxviii. f. 2. 
4. C. avellana. — Obovate, sphaeroidal, transversely striated ; striae nume- 
rous, remote, elevated, interrupted by a longitudinal sulcus ; aperture a little 
curved at the narrowest end. — Sovjer. Min. Conch, t. ccclxxviii. f. 3. 
OVULADJE. 
Gen. LXIV. VOLVA. — Canal at each extremity, produced ; 
external lip simple. 
295. V. patula. — Oblong, white, spirally striated ; pillai 
with a shallow furrow. 
Bulla patula, Penn. Brit. Zool. iv. 117* t. 70. f. 85, A. Don. Brit. Shells, 
t. cxliii. Mont. Test. Brit. 207. — North and South Britain, rare. 
Length about an inch, breadth half an inch ; outer-lip regularly rounded ; 
inner-lip protuberant in the middle, twisted and subreflected retrally ; back, 
rounded. 
GEN. CALPURNA. — Canals abbreviated ; external lip 
simple. 
1. L. Leathesi. — Elliptical, elongated, rather ventricose in the middle ; 
smooth ; a large plait on the pillar ; outer-lip smooth, very thick, and rather 
flattened. — Ovula Leath. Sower. Min. Conch, t. cccclx-xviii.— In the Crag at 
Walton. 
