68 



CONCHOLOGY. 



Univalves. 



VII. LlGE- 

 NA. 



Genus VII. Lagena. 



A. Mouth Dextral. 



Univalvtj, 



Shell Bollle-shaped, not attached to other bodies. 



Globosa, 



Laevis, 



Ketorta, 



Perlucida, 



Obs. We are indebted to Mr Walker for the infor- 

 mation which we possess concerning the species of this 

 genus. They were termed by him Lagena, but unac- 

 countably referred to the Linnaean genus of Serpula. 

 In Testacea Britannica, they are included in the genus 

 Vermicuhun. All those species which are at present 

 known, require the aid of the microscope for their exa- 

 mination. 



1 . Striata. Shell pellucid, glossy, white, with opake 

 longitudinal striae, suboval ; mouth produced, tubular, 

 small ; length about half a line. 



Walker's Test. Min. Bar. tab. 1. fig. 6. 

 Among sand on the English shores, not uncommon. 



2. Globosa. Shell white, transparent, smooth, sub- 

 ovate; mouth small and round. 



Walker's Test.Min. Bar. tab. 1. fig. 8. 

 Found at Sandwich, rare. 



3. Lcevis. Shell bluish white, transparent, smooth, 

 oblong ; mouth produced cylindrical. 



Walker's Test. Min. Bar. tab. 1. fig. 9. 

 From Sandwich, rare. 

 Marginata, 4. Marginata. Shell white, transparent, glossy, sub- 

 ovate, subcompressed, margin elevated; mouth a little 

 produced. 



Walker's Test. Min. Bar. tab. 1. fig. 7- 

 Found at Reculver, Kent, by Mr Walker, and on the 

 coast of Devon by Mr Montagu. 



5. Bctorta. Shell white, opake, suborbicular, mar- 

 gin elevated ; mouth produced recurved ; diameter not 

 half a line. 



Walker's Test. Min. Bar. tab. 1. fig. 10. 

 From Sandwich, rare. 



6. Perlucida. Shell white, transparent, glossy, globu- 

 bular, with six equidistant longitudinal ribs, and a small 

 knob at the base ; neck produced, mouth small ; length 

 one-tenth of an inch. 



Test. Brit. tab. 14. fig. 3. 

 Found at Sea Salter, Kent, by Mr Boys. 



7. Uriiw. Shell white, semitransparent, glossy, 

 smooth, urn-shaped, base furnished Avith a knob, mouth 

 produced, neck conical ; length one line. 



Test. Brit. tab. 14. fig. 1. 

 Found by Mr Boys among sand from Sheppey is- 

 land. 



8. Squamosa. Shell globose, mouth a little produ- 

 ced, striated, the striae appearing like the scales of a 

 fish. 



Test. Bint. tab. 14. fig. 2. 

 A minute species, found at Sea Salter by Mr Boys. 



Family IV. SPIRAL. 



In this division of shells, are included such spiral 

 univalves as are destitute of a pillar,, and whose whorls 

 or volutions are placed laterally, so that the last whorl 

 is on the outside forming the Margin. The family pos- 

 sesses two genera, Spirorbis and Planorbis. 



Genus VIII. Spirorbis. 



viii. Sn- Shell spiral, aperture orbicular, base adhering to other 



noKBis. bodies. 



Obs. The species of thi8 genus live in the sea, and 

 adhere to rocks, old shells, sea-weed, and corals. They 

 were included by Linnaeus in his genus Serpula. The 

 inhabitants belong to the class AnneliSet of Latreille. 

 The genus admits of two subdivisions. 



tfrn.-E, 



Squamosa. 



at us, 



Corrugp.tu's, 



1 . Communis. Shell opake, with three or four regu- Communis 

 lar lateral whirls, round on the upper part, and a little 

 wrinkled, with a cavity in the centre, base spreading, 

 diameter one eighth of an inch. 



Serpula spirorbis. Brit. Zool. tab. 91. fig. 155. 

 Donov. Brit. Sh. tab. 9. 

 Animal furnished with branched ciliated tentacula, 

 and a clavate or subfunnel shaped proboscis. Common 

 on stones, shells, and alga?. 



2. Spirillum. Shell white, glossy, subpellucid, with SpiriUumj 

 two or three subcylindrical whorls a little wrinkled, 

 sometimes placed laterally, and often rising one above 



the other ; diameter one line. 



Pultney, Kit. Dor. tab. 19. fig. 27. 

 This species usually resides on Algae; and, although 

 it resembles in appearance the former species, is never 

 found in its company. 



3. Granulalus. Shell white, opake, with two volu- Granulatus, 

 tions deeply grooved longitudinally, and wrinkled 

 transversely, size of the Spirorbis. 



Donovan, Brit. Sh. tab. 100. 

 Animal of a buff colour, with ten ciliated rays. 

 Found on stones and old shells. 



4. Carinatus. Shell Avhite, opake, dull, outer whorl c ar ; ni 

 rising into a carmated ridge on the top, middle con- 

 cave, interior volution inconspicuous, base a little 

 spreading. 



Test. Brit. p. 502. 

 Adheres to old shells. Common to England and 

 Scotland. 



5. Corrugatus. Shell white, glossy, strong, trans- 

 versely wrinkled, a small portion only of the second 

 volution visible, centre with a cavity ; diameter about 

 one-eighth of an inch. 



Test. Brit. p. 502. 

 Animal orange red, with eight greenish ciliated rays, 

 and a subfunnel shaped proboscis of the same colour. 

 Found on slate rocks at Milton, by Mr Montagu. 



6. Corneus. Shell horn coloured, regular, round, Corne'u? 

 with three whirls. 



Lin. trans, v. tab. 1. fig. 33, 34, 35. 

 Found at Pembroke, by Mr Adams. 



B. Mouth Sinistral. 



7. Helerostrophus. Shell white, dull, strong, with He;erostre 

 two or three whorls placed laterally, furnished with phu«, 

 three longitudinal ridges, wrinkled transversely, base 



flat ; spreading ; diameter a line. 



Test. Brit. p. 503. 

 Found on stones, shells, any alga?, common. 



8. Sinislrorsiis. Shell white, glossy, semipellucid, Sinistror- 

 with two or three lateral whorls frequently coiled upon su8 > 

 one another, and slightly wrinkled transversely ; di- 

 ameter a line. 



Walker's Test. Min. Bar. tab. 1. fig. 13, 14. 



Usually found on lobsters ; we have observed it on 

 old shells of Cardium aculeatum. 



9- Minutus. Shell dirty white, with two or three Minutus, 

 lateral whorls, wrinkled transversely, and sometimes 

 furnished with a dorsal carina, base rounded ; diameter 

 a quarter of a line. 



Test. Brit. p. 505. 



Animal with ciliated feelers and a clavate proboscis. 

 Inhabits the branches of Corallina officinalis. 



10. Conicus. Shell dirty white, dull, opake, whirls Conicus, 

 two, the outer one large, and embracing the other, with 

 a carina along the upper side, conical, mouth towards 

 the top. 



In a young state, it resembles the preceding species ; 



