204 PROCEEDINGS OF THE 



been presented to him by the Kev. Dr Gloag of Blantyre, probably 

 belonged to a new and undescribed genus. 



PAPER READ. 



On the Nudlhranchiate Mollusca of the SJiores of the Cumhraes. 

 By Mr David Eobertson, illustrated by specimens. 



In bringing forward a list of the Nudibranchs of the Cumbraes, I 

 have to remark that it must not be understood it has any i:)re- 

 tensions to an exhaustive list of the species which may be obtained 

 on the shores of these islands, but merely as a beginning, under- 

 taken in the hope of enlisting more workers for the better investi- 

 gation of this much neglected but most interesting family. 



One great drawback to progress arises in many cases from the 

 necessity of identifying them Avhile they are in life, many not 

 surviving long when removed from their natural condition. 



Like many other animals, they make their appearance on our 

 shores in greater or lesser numbers at particular seasons of the 

 year. I find them most abundant in February, March, and April, 

 months favourable for collecting on account of the spring tides. 



Unfortunately, from the coldness and uncertainty of the weather 

 of these months, few naturalists choose them for their holidays at 

 the coast, and from this cause doubtless many of the best opportu- 

 nities of capturing these animals are lost. 



The importance of low ebbs for collecting Nudibranchs will be 

 seen by glancing over the accompanying list, when it wdl be 

 found that more than four species have been obtained on the 

 shore, for one obtained exclusively by the dredge. That circum- 

 stance becomes the more prominent by the fact, that I have 

 occupied much more time "with the dredge than Avith shore work. 



For working out a local list in any branch of the marine 

 invertebrate fauna, I know no i^lace so favourably situated as the 

 rich shores of the Cumbraes ; nor is there any place known to me 

 where such a length and variety of shore can be reached with so 

 much convenience and so little toil. There is not less than twenty 

 miles of shore line to hunt upon ; and making full allowance for 

 rough ground, twenty sc^uare miles of sea to dredge in, which, at 

 any point, scarcely exceeds six miles from the village of Millport. 



In tlie valuable monograph of British Nudibranchiate Mollusca, 

 by Alder & Hancock, ninety-one species are recorded; of these 

 twenty-nine are from Scottish, habitats, and twenty-two of that 



