1386 = Mr. E. Waller on @ new British Species of Rissoa. 
markings exactly alike in every individual of the shoal, would 
indicate with tolerable certainty that it had never been observed 
before ; for, had it been otherwise, these peculiarities, being so 
very striking, could not possibly have been overlooked. But 
this I leave to more profound naturalists to determine. 
Kirkwall. 
[There is little doubt that this Dolphin is Lagenorhynchus 
leucopleurus of my Catalogue of Cetacean Animals in the British 
Museum, published in 1850, p. 97, which Mr. Knox (under the 
name of Delphinus Tursio) describes as found at the Orkneys in 
May 1885. The skeleton of this specimen is in the Museum of 
the University of Edinburgh.—J. E. Gray. | 
XV.—On a new British Species of Rissoa. 
By E. Water, Esq. 
To the Editors of the Annals of Natural History. 
GENTLEMEN, 
Having accompanied my friend Mr. Jeffreys in several of his 
late excursions to the Shetland Islands, I have had the oppor- 
tunity of seemg, on their first capture, many of the novelties 
added to our fauna in those distant and difficult dredgings. I 
know his unwillingness to anticipate the interest properly re- 
served for his ‘ British Conchology,’ now in course of publica- 
tion, by a previous description of any of the new shells; but I 
am tempted to infringe, with his permission, on this rule in one 
instance. In the home examination of sand obtained to the 
north of the Island of Unst, at a depth of 85 fathoms, I found 
a Rissoa which appears to have been hitherto undescribed and 
unnamed. I wish to couple with it the name of Mr. Jeffreys, 
whose persevering and long-continued labours have added so 
largely to our knowledge of British conchology. I would there- 
fore feel obliged by your publishing in the ‘ Annals’ the follow- 
ing description of Ressoa Jeffreysi, one of the novelties announced 
in the Report to the British Association (1863) on the Shetland 
dredgings. 
I remain, Gentlemen, 
Lissenderry, Aughnacloy, Your obedient Servant, 
June 29, 1864. Epwarp WALLER. 
Rissoa Jeffreysi, n. sp. 
Shell conical, moderately strong, somewhat glossy and semi- 
transparent. 
Colour white. 
