136 Mr. E. WaUer on a 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 1835. The skeleton of this specimen is in the Museum of 

 the University of Edinburgh. — J. E. Gray.] 



XV. — On a new British Species o/ Rissoa. 

 By E. Waller, 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 seeing, 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 oi Rissoa Jeffreysi, one of the novelties announced 

 m- the Report to the British Association (1863) on the Shetland 

 dredgings. 



I remain, Gentlemen, 

 Lissenderry, Aughnacloy, Your obedient Servant, 



June 29, 1864. Edward Waller. 



Rissoa Jeffreysi, n. sp. 



Shell conical, moderately strong, somewhat glossy and semi- 

 transparent. 

 Colour white, 



