160 POPULAR BRITISH CONCHOLOGY. 



veloped as tliey are, afford but a poor substitute for real 

 powers of vision ; while in others even these are wanting. 

 The Btromhidce generally have large and handsome shells, 

 with spreading lips to the apertures, of which the pink- 

 mouth couch-shell, so commonly used in ornamental garden- 

 work, and hawked about the streets, is a familiar example. 

 I mention the family, all out of place as it is here, in order 

 to make known to my readers some very interesting obser- 

 vations, and the result of some rather cruel experiments, 

 by the Rev. Lansdowne Guilding with respect to the eyes 

 and ears of these mollusca. That gentleman remarks that 

 if Mr. Brayley (a writer on the subject in the ^Zoological 

 Journal^) "had an opportunity of examining the giant 

 Stromhidm which inhabit the Caribbean Sea, he would find 

 the eyes more perfect than those of many vertebrated animals. 

 In these he would see with astonishment a distinct pupil, 

 and a double iris, equalling in beauty and correctness of 

 outHne those of birds and reptiles. On dissection he would 

 discover a vitreous and aqueous humour, and the black pig- 

 ment, which will be sought for in vain in the Kelic'idcB. 



"The Stromhid(B also possess the sense of hearing, or, what 

 seems allied to it, the sense which the perplexed entomolo- 

 gist Lehmann has termed " aeroscepsy.''^ I lately suspended 



