286 SMART AND COOKE ; MARINE SHELLS OF SCILLY. 



of Scillonian mollusca is kept at Tresco Abbey, in which the 

 species found by Lord Vernon were once distinguished by a 

 special mark. This list has received subsequent additions from 

 various hands — some of them manifestly unscientific — and the 

 result has been to import into the list not a few species whose 

 true habitat is obviously very distant from Scilly. 



Dr. Jeffreys informs us that Mr. Barlee at one time dredged 

 in Scilly. Considerable and trustworthy additions were made 

 to the Abbey list by the Rev. J. H. Jenkinson, and also by his 

 son, F. H. Jenkinson, Esq., of Trinity College, Cambridge. 

 These additions, if of shells which we were not able to confirm 

 ourselves, are printed in a separate list at the end of ours, and 

 may be taken as authentic. 



A third list contains those shells which are on the Abbey 

 list, but are confirmed neither by Mr. Jenkinson's nor our own 

 researches, and therefore must be regarded generally with con- 

 siderable, and in certain obvious cases with complete mistrust. 



But it will be seen how much room there was for work on 

 the subject when we mention that among thirty-six species now 

 appearing for the first time as Scillonian, so abundant a shell 

 as Littoriiia 7ieritoides, living in a habitat specially accessible, 

 had appeared in no list before the present. 



Perhaps the shells which do not occur on the list are as 

 interesting as those which do. The more prominent absentees 

 are Madra stultoruin, Tellina halthica, Donax anatijius, D. poli- 

 tus, Mya arenaria, M. truncata, Solen ensis, Natica monilifera, 

 and Calyptraea chinensis. Most of these might fairly have been 

 expected to occur in the sandy bays which abound, but they 

 are either entirely absent, or, as will be seen from the additional 

 lists, have occurred as solitary individuals some years ago, and 

 have never made their appearance since. Tellina balthica, as 

 an estuary shell, might fairly be excused occurring, but curiously 

 enough Scrobicularia piperita, much more of an estuary shell 

 than the Tellina, does occur. None of the Pholas tribe are 

 found in the Scilly Islands, the hard granite offering them no 

 chance of lodgement. 



J.C, iv., Jan., 1885. 



