66 MOLLUSCA. 



thinness of the animal is proportioned to the narrowness of the 

 aperture through which it issues; its tentacula and proboscis ur<- 

 highly protractile; the eyes are placed on the outer side of the 

 former, and near the point; the operculum situated obliquely on 

 the hind-part of the foot, is too narrow and short to close the whole 

 of the aperture. 



The shells of this genus, being usually ornamented with the most 

 beautiful colours, are very common in cabinets. The seas of Europe 

 produce very few *. 



They are distinguished by the flatness or slight projection of the 

 spire ; by the whorls being tuberculated or not ; by its being more 

 salient and even pointed, and furnished, or not, with turbercles. 



There are some in which the spire is sufficiently salient to give 

 them a cylindrical appearance, in which case it may be either smooth 

 or tuberculated f . 



The appellation of crowned spire is applied to that which is studded 

 with tubercles, 



, Lin. 



The spire projecting but little, and the aperture narrow and extending 

 from one extremity to the other ; but the shell, which is protuberant 

 in the middle, and almost equally narrowed at both ends, forms an 

 oval, and the aperture in the adult animal is transversely wrinkled on 

 each side. The mantle is sufficiently ample to fold over and envelope 

 the shell, which at a certain age it covers with a layer of another 

 colour, so that this difference, added to the form acquired by the 

 aperture, may easily cause the adult to be taken for another species. 

 The animal has moderate tentacula, with the eyes at their external 

 base, and a thin foot without an operculum. 



The colours of these shells, also, are extremely beautiful ; they are 

 extremely common in cabinets, though with' very few exceptions they 

 all inhabit the seas of tropical countries J. In the 



OVULA, Brug. 



The shell is oval, and the aperture narrow and long, as in Cypra, 

 but without plicae on the side next to the columella ; the spire is con- 

 cealed, and the two ends of the aperture equally emarginated, or 

 equally prolonged in a canal. Linnaeus confounded them with the 

 Bullae, from which Brugieres has very properly separated them. The 



* For the species of this beautiful genus see the article and the plates of Brugi^res 

 in the Encycl. Method., where they are .extremely well described and figured, 

 and the enumeration still more complete than in the Ann. du Mus. XV, by M. de 

 Lamarck. 



t Species with a crowned spire : Con. cedonulli, L., a shell much sought for, and 

 of which there are many varieties, Encycl. Method., pi. 316, f. 1 ; Con, marmoreus, 

 L., Enc., pi. 317, f. 5; Con. arenaius, Brug., Encycl., pi. 320, f. 6, &c. 



Species with a simple spire: Con. lUlmtlus, L., Encycl., pi. 326, f. 1 ; Con. 

 tessellatus, Brug. Km-., pi. 326, f. 7 ; Con.rirgo, Brug. Enc. pi. 325, f. 5, &c. 



J For the species see the genus Cyprtra, Gmel., and the figures collected by Bru- 

 gieres for the Encyclop., the Gen. of shellsby Sowerby, No. XVII, and particularly 

 a Monograph by M. Gray, published in the Zool. Journal, Nos. 2, 3, and 4. 



