THE 



ZOOLOGICAL JOURNAL. 



1832—1834. 



Art. Lr. Remarks on the nature of the Respiratory Organs 

 in certain littoral Mollusca of 3Iadera. By the Rev. R. T. 

 LowK, A. 31. 



In reperusing, after a considerable interval, my paper in the 19th 

 number of the Zoological Journal, (page 280,) in which I detailed a 

 series of experiments, instituted with a view to ascertain something of 

 the nature of the respiratory organs in Melampus, Pedipes, and Trun- 

 catella ; it has struck me that I have been too hasty in regarding some of 

 my conclusions as positively or finally established : or rather, perhaps, 

 in not sufficiently explaining, or defining, the actual extent to which 

 my resulting speculations might safely, and legitimately, be admitted. 



It is very certain, from the fact of these Mollusca surviving total im- 

 mersion for so long a period as they did, in water, that a remarkable 

 difference in their powers, in respect to an ability for enduring complete 

 deprivation of atmospherick air, from those of our land Pulmonifera 

 in general, may be safely considered as established.* Now from this 



* It is essential to remark that I do not consider this position invalidated by 

 the following quotations from the observant Miiller, or others of a similar 

 character. Speaking of his Helix pellucida (Vitrinn, Drap.) he observes, 

 " Limacem in aqua perire affirmat Clariss. GeofFroi j hoc sese nobis, etiamsi 

 " periculum in pluribus fecerimus, minus probavit; in aquam cnim immissi, 

 " fundum statim petierunt, ac totum corpus e tcstJl protulerunt; tentacula 

 Vol. V. cc 



