Bibliographical Notice. 443 



I consequently found myself in the presence of several (at 

 least two, perhaps three) species of animals of the same size, 

 nearly allied in their organization, but very distinct in the ver- 

 tebral arrangement of the neck, and all developed in the same 

 medium. Anatomy was enriched by a new fact, and at the same 

 time created a new difficulty in the classification of the fossil 

 cuirassed Mammalia, which is already rather confused. 



BIBLIOGRAPHICAL NOTICE. 



British Conchology, Vol. III. Marine Shells, comprising the re- 

 maining Conchifera, the Solenoconchia, and Gasteropoda as far 

 as Littorina. By John Gwyn Jeffreys, F.R.S., F.G.S., &c. 

 London: Van Voorst. 1865. 



Each succeeding year brings to us another volume of Mr. Jeffreys's 

 new work on the British Mollusca, which is coming out with praise- 

 worthy regularity. At the present rate of progress two more vo- 

 lumes will be required to complete the subject. We propose to 

 continue the course which was adopted in noticing the preceding 

 volumes, and compare the genera and species here described with 

 those contained in Forbes and Hanley's ' History of the British 

 Mollusca,' which, up to the present time, has been the standard 

 authority on this portion of the marine zoology of our islands. 



The following are the generic changes. Sphenia of Turton is 

 merged in Mya, and Cochlodesma in Thracia. Panopcea Norvegica 

 is regarded by our author as a Saxicava and not a Panopcea ; but 

 the latter genus is not excluded from our lists, since the little shell 

 figured by Forbes and Hanley (pi. C. figs. 1-3), but not named 

 (vide vol. iv. p. 248), appears here with the name of Panopcea pli- 

 cata, Montagu. The genus Patella is divided, and P. pellucida is 

 placed in the genus Helcion of De Montfort : on the other hand, 

 Pilidium fulvum falls into Tectura of Cuvier, a name adopted 

 by Mr. Jeffreys instead of Acmcea of Eschscholtz. Capidus, De 

 Montfort, supersedes Pileopsis, Lamarck ; and, lastly, the genus 

 Cyclostrema of Marryat is adopted in the family of the Trochidre 

 for the reception of three little shells, — C. Culterianutn, Clark 

 (=.Skenea Culteriana, F. & H.) ; C. nitens, Philippi (=Trochus 

 pusillus, F. & H.); and C. serpuloides, Montagu ( = Skenea divisa, 

 F. & H.). 



The following species, which were admitted in the ' History of the 

 British Mollusca,' are excluded in vol. hi. of 'British Conchology:' — 

 Corbula ovata, Teredo palmulata, and Trochus conulus, as not being 

 indigenous ; Skenea costulata, as occurring only in a fossil state ; 

 Pandora obtusa, Thracia villosiuscula, Corbula rosea, Saxicava 

 arctica, Skenea Icevis, and Patella athtetica, assigned respectively as 

 varieties to Pandora incequivalvis (P. rostrata, F. & H.) ; Thracia 

 papyracea, Poli (T. phaseolina, F. & H.) ; Corbula gibba (C. 

 nucleus, F. & H.) ; Saxicava rugosa ; Cyclostrema nitens ; and 



