WATSON : MARINE MOLLUSCA OF MADEIRA. 369 



the very able help of Mr, Edgar Smith. At Cambridge I was 

 deeply indebted for kindness to the Vice-Chancellor and to 

 Mr. Clark, the Curator of the Anatomical Museum, besides 

 private friends. I regret that the pressure of other duties has 

 for 14 years prevented me turning these very favourable oppor- 

 . tunities of study to any general good. 



Of Mr. McAndrew's 127 named species, two must have 

 slipped into his list by mistake, viz., Dentalium dentalis and 

 Neritina viridis. Both of them are marked as 'frequent,' but of 

 neither, I think, has any specimen been since got at Madeira. 

 In neither the British Museum nor the Cambridge collection do 

 any specimens from Madeira exist, though some are marked as 

 having been got at the Canaries. 



A third species, also noted as ' frequent,' but which has 

 escaped all other seekers, and does not exist in the B. M. 

 Madeira specimens, is Marginella guancha — a species not un- 

 common in the Canaries as Mr. McAndrews collection at 

 Cambridge testifies, though d'Orbigny, its author (Moll. d. 

 Can., p. 88) believes it to be 'assez rare.' I had no doubt that 

 with the two previous it ought to be excluded from the Madeira 

 list, but to my amazement I came on a solitary specimen of it 

 quite lately in sand which distinctly bears the label 'from 

 Madeira.' It seems to me certain then, that it must be erased 

 from McAndrew's list in any case, and can only be admitted at 

 all as 'doubtful' into the Madeira reckoning. 



. Mr. McAndrew's named list, then, contains 124 species 

 which with a few exceptions are correctly named. The excep- 

 tions are these — 



Rissoa purpurea. — This, as has already been pointed out 

 by Manzoni (Journ. de Conch., xvi., 248, 1868), is a mere slip 

 of the memory for R. violacea Desmarest. 



Chiton fascicularis. — Mr. Gwyn Jeffreys (Brit. Conch., Ill, 

 212) in quoting McAndrew's localities for these species remarks 

 'that some of the southern localities which have been published 

 probably belong to Chiton discrepans.\ This is certainly the 



