History of British animals - University of Guam Marine Laboratory

Volva. MOLLUSCA. SOLENOSTOMATA. 331Length about fths of an inch ; breadth |ths; of a pink colour with orwithout (C. arctica) dark dorsal spots ; stria? distinct, bifurcated at the sides.In the young state, the shell is smooth, except some appearances of striae onthe inner-lip, and the apex exhibits two whorls,— or three in which state itis the C. bullata of Mont. Test. Brit, 202. t. vi. f. 1. The C. pediculus differsfrom the present species, with which it has been frequently confounded,by the roughness of the stride, and the presence of a longitudinal dorsalgroove.EXTINCT SPECIES.1. C. oviformis.— Egg-shapped, tumid, smooth, slightly marginate; aperturewidest at the lowest end, left side of the aperture obscurely toothed ; rightlip involute, tumid Sower. Min. Conch, t. iv.— London Clay.2. C coceinelloides.—Ovate "sphaeroidal, transversely striated ; striae numerous,acute, not interrupted ; aperture slightly arched, not contracted inthe middle Sower. Min. Conch, t. ccclxxviii. f. 1.— Suffolk Cvag.3. C. retusa.— Obovate, sphaeroidal, transversely striated ; striae elevated,uninterrupted, few, remote ; aperture a little curved at the narrowest end.—Sower. Min. Conch, t. ccclxxviii. f. 2.4. C. avellana.— Obovate, sphaeroidal, transversely striated ; striae numerous,remote, elevated, interrupted by a longitudinal sulcus ; aperture a littlecurved at the narrowest end.— Sower. Min. Conch, t. ccclxxviii. f. 3.OVULAD.E.Gen. LXIV. VOLVA.— Canal at each extremity, produced ;external lip simple.— 295. V. patula.— Oblong, white, spirallystriated ;pillaiwith a shallow furrow.Bulla patula, Penn. Brit. Zool. iv. 117- 1. 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 lipsimple.1. L. Leathes'%.— Elliptical, elongated, rather ventricose in the middle ;smooth ;a large plait on the pillar;outer-lip smooth, very thick, and ratherflattened—Ovula Leath. Sower. Min. Conch, t. cccclxxviii.—.In the Crag atWalton.