J ■ 



'* 



448 Bihliography^ 



radiata, Fer., turns to it at its proper alphabetical place in the genus He- 

 lix, and is there told that it is now known as BuUmus detritus^ Miiller. 

 For this he searches in the genus Bulimus^aud there finds it enumerated^ 

 with its complete synonymy, and reference to eleven authors who de- 

 scribe or figure it. The generic arrangement is essentially that of La- 

 marck with such modifications as the progress of science has rendered 

 necessary. In the adoption of new genera proposed by later authors, 

 the author has usually pursued a judicious course. Those genera which 

 are founded upon sure, important, and identifiable characteristics, are for 

 the most part received, while those founded upon trivial and uncertain 

 points, indicative of groups of species merely, have been rejected. In j| 



the great family of Helicidae, the species are so numerous that the 

 temptation to adopt new generic distinctions is great, and a more ad- 

 vanced state of knowledge may perhaps justify such distinctions, but the 

 author has wisely judged that our acquaintance with the soft parts of the 

 widely varying species of this family is yet too limited to sustain even as 

 subgenera the names proposed by Beck, Gray, Albers and others. An 

 alphabetical index to the various genera, subgenera and synonyms men- 

 tioned in the catalogue greatly facilitates its use. 



To amateur collectors the work may become specially useful for 

 other purposes. By checking off upon it their own species, they be- 

 come furnished with a catalogue of their own collections with little or no 

 labor, and the printed sheets serve for very neat labels. The collection 

 of Dr. Jay is arranged in the order of the catalogue, each specimen 

 being numbered to correspond with it. Each species is placed upon a 

 separate stand with a printed label, and all protected by glass. The 

 whole affords an admirable model for the arrangement of natural his- 

 tory collections. 



In spite of all the author's care, a few errors have crept in, but few- 

 er than might have been expected in a work of so much detail. These 

 we may hope will be corrected in the supplements which he may 

 hereafter find it necessary to publish. 



The work may be obtained from John Wiley, New York, J- B. Bail- 

 liere, Paris, or from the author. J* ^' "^• 



4. A Synopsis of the Classification of the British Palceo::oic Rocks; 

 by the Rev. Adam Sedgwick : with a detailed Systematic Description 

 of the British Palaeozoic Fossils in the Geological Museum of the Uni- 

 versity of Cambridge; by Frederick McCov, Prof. GeoL and Min., 

 Queen's Coll., Belfast. Part 2, Paljeontology, 184 pp. 4to, with 11 litho- 

 graphic plates. — We learn in the preface that this volume is the first 

 fasciculus of Prof. McCoy's Descriptive Catalogue of the British Palae- 

 ozoic Fossils, placed by^Prof. Sedgwick in the Woodwardian Museum. 

 . This part is devoted to the Kadiata and Articulata. The second which 

 is promised before the close of the year, will include the Mollusca and 

 Vertebrata, and complete the series. The whole number of plates 

 when completed will be 23. This extensive work is in the hands of 

 one of the ablest Palaeontologists of Great Britain, and is well executed. 

 The number of new species and new genera is large, and if our limits 

 did not forbid, we should take pleasure in transferring the descriptions 

 of the added genera to our pages. 



