PREFACE. 



The motives which induced me to collect the materials 

 for this work, were such as, I think, may reasonably be 

 approved of by those for whom it is intended. Having 

 been recalled to my native place, in May, 1841, I 

 naturally felt a desire of renewing my acquaintance with 

 the productions of a district often traversed by me while 

 prosecuting my studies at the Universities there, and not 

 being aware of any very important investigations having 

 been conducted in this much neglected, though not un- 

 interesting, part of Scotland, with reference to its Zoology, 

 I thought it might be useful to describe some or all of 

 its numerous animals. I therefore at once commenced 

 an examination of the Mammalia, Birds, Reptiles, Fishes, 

 Mollusca, Insects, and Radiata, the results of which I 

 intend, in due time, to lay before the public. Thinking, 

 however, that the pupils whom I have to initiate in the 

 Science to which my labours have, for many years, been 

 directed, could not acquire much practical acquaintance 

 with most of these tribes of animals, in the winter season, 

 when engaged with their various academical studies, I 

 selected a branch of Zoology which I thought capable of 

 affording them greater facilities for observation than any 

 other. I was further induced to undertake the work by 

 remembering that a descriptive catalogue of the Mol- 

 lusca of the district was a desideratum to the Zoologists 

 of other parts of the kingdom. 



My observations having been continued, as opportunity 

 was afforded, until the number of species had increased 

 to a much greater extent than, from the apparently un- 

 favourable nature of the district, and the evil reports of 

 the very few shell-gatherers known to me, I could have 



