144 



A NEW SHELL-BOOK. 



The Shell-Collector's Handbook forthe Field. By J. W. Williams. M. A., D.Sc, 

 Editor of 'The Naturalists' Monthly.' London: Roper & Drowley, 29, Lud- 

 gate Hill, E.G. 1888. Small 8vo, 148 pages, interleaved. 



The idea of this little book is an excellent one, as a handy 

 manual for the pocket, with concise and tersely-worded descriptions — 

 or rather diagnoses — is one calculated to conduce to the convenience 

 of every working conchologist. Such a work from the pen of a 

 conchologist of large experience — both in the field and in the study 

 — would be of much value. We are afraid, however, after examina- 

 tion of the one before us, that in spite of the excellence of its plan, 

 the manner of its execution requires much emendation before it can 

 become the guide which field-conchologists require. Its inaccuracies 

 are somewhat too numerous for the book to be considered satisfactory. 

 For instance, the author describes two varieties of Arion ater thus : 



V. bicolor ( V. Brock) Moq, : Animal dark brown or blackish, sides yellowish 

 or orange, 



V. albolateralis {Ashford) : Animal dark brown or blackish, with the sides 

 white, and the foot-fringe orange ; the two last colours being sharply defined from 

 one another. 



Here are various errors. By what principles of nomenclature one 

 name is ascribed to v. Brock and the other to Ashford we do not 

 know. The two descriptions read too much alike, and neither of 

 them is accurate ; when our author speaks of the two last colours 

 being sharply defined from one another, the innocent reader naturally 

 supposes this statement to refer to the white side and the yellow 

 fringe, whereas in the true albolateralis the sharp contrast is between 

 the black of the back and the white of the sides, and the colour of 

 the fringe has nothing whatever to do with the specific character. 

 The writer has seen examples with the fringe whitish as well as with 

 it yellow. The descriptions ought to read thus : 



V. bicolor Moq. Animal with the back brown and the sides yellow or orange, 

 the two colours being sharply defined from each other. 



V. albolateralis Roeb. Animal with the back black and the sides pure white, 

 the two colours being sharply defined from each other. 



We notice that in two instances at least our author gives forms 

 twice over, Arion bourguignati figuring as a species on p. 87, and 

 as a variety of A. horteiisis on p. 86 ; and Succinea virescens as a 

 species on p. 97 and also as var. vitrea (Moq.) on p. 96, and var. 

 vitrea (Jeff.) on p. 97. The tenacity of errors is shown by the 

 retention of the mythical Arion flavus. And why is Limax made a 

 i-w/^genus? Our author speaks oi^'Ainalia {Liiiiax) gagates,' send of 

 Eulimax {Li7nax) Icevis," and so throughout the genus. A. glossary 

 is given at the end, a full index at the beginning, and two chapters on 

 anatomy are also given, followed by directions for collecting, and a 

 conspectus of the classes, orders, famihes, and genera. — W.D.R. 



Naturalist, 



