MOLLUSCA. 
133 
its slope being convex, and about a third shorter than the pos- 
terior side ; colour cream-white. Breadth nearly two-twelfths 
of an inch ; length not quite a twelfth. 
Found among the roots of aquatic plants, in a ditch between 
Aberdeen and Spital. 
Genus Psammobia. — (Page 101.) 
8. Psammobia Florida, pi. XXXIX, f. 30. 
Psammohia jloridai Turton, Biv., p. 86, pi. , f. 6. 
Shell transversely oblong-ovate, rather convex, equally round- 
ed at both sides ; hinge with a single cleft tooth in one valve, 
with a pit on each side for the reception of two teeth in the 
opposite valve; surface smooth, with close-set, concentric strise, 
and minute longitudinal ones; variously marked with transverse 
zones of red or yellow, and longitudinally radiated ; inside vary- 
ing from pale yellow to rich reddish -lilac. Length half an inch; 
breadth one inch. 
Inhabits the Western coast of England, and the Eastern of 
Ireland. 
9. Psammobia costulata, pi. XXXIX, f. 34. 
Psammobia costulata, Turton, Biv., p. 87, pi* 6, f. 8. 
Shell transversely oblong-oval, thin, slightly angular at the 
anterior end, where there are about twelve fine, divergent, lon- 
gitudinal ribs emanating from the umbones, which are straight, 
a little prominent, and nearly central ; whole surface with very 
minute, longitudinal, and somewhat more open transverse striae ; 
colour varying from pale yellow to deep purple, and marked 
with blotches and stripes of pale crimson ; hinge with a slightly 
cleft tooth in one valve, locking between two in the other, one 
of which is slightly cloven ; inside same colour as the external 
surface, but more vivid. Length half an inch ; breadth an 
inch. 
Found at Torbay and the Irish Channel. 
Genus Sphenia. — (Page 104.) 
4. Sphenia costulata. 
Sphenia costulata, Macgillivray, Moll. Ab., p. 301. 
Shell convex, very thin, subdiaphanous and glossy, trans- 
versely-ovate, equally rounded at both sides, the anterior one 
considerably shorter ; umbones small, and slightly protruding ; 
whole surface with faint, concentric striie, and with about 
fifteen slightly elevated, radiating ribs ; tooth thin, and of an 
elongated lamellar form ; colour white. Length a twelfth of 
an inch ; breadth a twelfth and a half. 
Found among shell sand, from the Bay of Cruden, by Mr. 
Murray. 
Genus 1. — Stylifer. — Broderip. 
Shell thin, pellucid, turbinated ; spire narrow, its apex a little 
off the perpendicular ; aperture wide below, and narrowed above, 
with an acute termination. 
The shells of this genus burrow in the rays of star fish. 
1. Stylifer astericola, p. 10, pi. X, f. 40, 41. 
Phasianella stylifera. 
The genus Stylifer is now transferred to the family Serpu- 
lacea, but we have great doubts as to this being its proper 
situation in the system. 
ALPHABETICAL LIST 
OF 
THE PRINCIPAL AUTHORS TO WHICH REFERENCE HAS BEEN MADE IN THE FOREGOING WORK. 
Adams, Micros. Essay on the Microscope, &c., by George Adams, 2nd 
Edit. 4to. London, 1798. 
Adams, Linn. Tr. Description of some minute British Shells, by John 
Adams. Transactions of the Linnean Society, V. 
Alder, Mag. Zool. and Bot. Notes on the Land and Fresh Water Mol- 
lusca of Great Britain, &c. Magazine of Zoology and Botany, II, 
by Joshua Alder. 
Catalogue of Land and Fresh Water Testaceous Mollusca, found 
in the Vicinity of Newcastle-upon-Tyne, &c. Transactions of the 
Natural History Society of Northumberland. 1830 Ib., Sup. 
1817. 
Alten, J. W. Von. Systematiche abhandlung iiber die Erd-und Fluss- 
conchylier Augsbourg, &c. 1812. 
Bean, Mag. Nat. Hist. Undescribed Shells in Loudon’s Magazine of 
Natural History, VIII, by William Bean. 1834. 
Bennet, Zoological Journal, I, p. 298. Description of an hitherto 
unpublished Species of Buccinum, by E. T. Bennet. 1824. 
Berkeley, Zool. Journ. Description of several British Shells, &c. Zoo- 
logical Journal, IV. and V, by the Rev. M. G. Berkeley. 1828-9. 
Brard, Coq. de Paris. Histoire des Coquilles terrestres et fluviatiles qui 
vivent aux Environ de Paris, by C. Prosper Brard, 2 vols. 8vo. 
1808. 
Broderip, Zool. Journ. Description of two new Species of Buccinum, 
by W. J. Broderip. Zoological Journal, V. 1835. 
2 L 
Brown, Conch. Text Book. The Conchologist’s Text Book, according 
to the system of Lamarck, by Captain Thomas Brown. 1833. 
Edin. Journ. Nat. and Geo. Science. Description of several 
new British Shells. Edinburgh Journal of Natural History and 
Geographical Science, I. 1827. 
Article Conchology. Encyclopedia Britannica, sixth Edition, 
VI, p. 385. 
Article Conchology. Encyclopedia Edinensis, II. p. 533. 
Article Conchology. Popular Encyclopedia, II. p. 374. 
Account of the Irish Testacea. Memoirs of the Wernerian 
Natural History Society, II. 1817. 
Bruguiere, Encyclopedie Methodique. Article Vers. 4to. 1792. 
Chemnitz. New System of Conchology, in German, by F. H. W. 
Martini and J. H. Chemnitz, 11 vols. 4to. 1769-1788. 
Clai'ke, Ann. and Mag. Nat. Hist. On the Species of the Genus Limax 
occurring in Ireland, by the Rev. B. J. Clarke. Annals and Maga- 
zine of Natural History, XV, p. 332. 
Da Costa. Historia Naturalis Testaceorum Britannia;, English and 
French, by Emanuel Meades Da Costa, 4to. London, 1778. 
Dillwyn, L. W. Descriptive Catalogue of Recent Shells, 2 vols. 
Donovan, Edward. Natural History of British Shells, 5 vols. royal 
8 VO. 1804. 
Drapernaud, J. P. R. Histoire Naturelle des Mollusques TeiTestres et 
Fluviatiles de la France, 4to. 1805. 
