54 Mollusks. 



little more than the cost of paper and printing, we have here a work 

 which, to the practical conchologist, more especially if he be likely 

 to visit foreign climes, is of the greatest value. The volume con- 

 tains 89 plates, in all embracing upwards of 630 figures, illustrating 

 each of the genera into which the Mollusca are now divided, the ar- 

 rangement being that published by Mr. Gray in the Synopsis of the 

 British Museum. In the preface to this work, written by Mr. Gray, 

 he says — 



" The tracings from which these etchings of Molluscous animals have been taken, 

 were originally made by Mrs. Gray for my use, with the view to their being added to 

 my collection of figures of shells, and to aid me in their arrangement. Hoping that 

 others may find such a collection of figures (many of them copied from expensive 

 works, and brought together from sources not easily accessible to conchologists in ge- 

 neral), as useful as they have been to myself, I induced Mrs. Gray to make slight 

 etchings of them, which afi'orded her an interesting occupation during a period when 

 she was confined to the house by ill health." 



The book being thus superintended by Mr. Gray himself, and the 

 figures apparently carefully collated with the originals, we can con- 

 scientiously recommend it to every student of Conchology. No one 

 about to visit foreign climes ought to be without it, as with the op- 

 portunities he will then have of studying the animals alive, he will 

 find this collection of good figures invaluable. 



At the present day we believe it to be quite unnecessary to attempt 

 to show the necessity for the conchologist to study the animals which 

 form the shells. We shall content ourselves with pointing out one 

 instance from the book before us, of the interest and value attached to 

 such a study. Most of our readers are perhaps well acquainted with 

 that beautiful, elegant and brilliantly polished genus of shells called 

 Olives. If we examine one of these shells we find a strong and rather 

 broad raised belt across the front of the shell; and round the spire we 

 observe a deep groove or canal. How are these formed ? Let us 

 turn to plate 18, and we shall see that the animal has a singular acute 

 reflected process in the front of the mantle, situate just behind the 

 siphon ; and at the hinder angle a thread-like elongated body, by 

 means of which organs, as the shell is moulded as it were upon the 

 body of the animal, it forms this belt and groove. The difficulty is 

 thus solved at once, and a beautiful adaptation of means to an end is 

 here pleasingly illustrated. 



A second volume of this work is announced as forthcoming, and 

 we have no doubt it will reflect great credit upon its amiable author- 

 ess, and do much to extend the knowledge of an interesting class of 

 creatures, which have hitherto been too much neglected. W. 



