18 LITTORlNID^l. 



of the spire, the first minute and somewhat prominent : suture 

 deep : mouth roundish- oval, scarcely expanding outwards : 

 outer lip thin, not much incurved above : inner lip reflected 

 on the pillar and at the base, behind which is a slight depression 

 or chink : operculum filmy, with a short spire, and delicately 

 striated. L. 0-1. B. 0-065. 



Yar. diversa. Longitudinal ribs finer and more prominent, — 

 a character which gives this variety a different aspect. 



Habitat : Widely distributed, in the lower part of the 

 laminarian zone and throughout the coralline zone, from 

 Guernsey to Unst, at a depth of from 1-95 f. The 

 variety is from Skye and Shetland. R. punctura occurs 

 in upper tertiary deposits in Sussex (Godwin- Austen) , 

 Ayrshire (Landsborough, fide Thompson) , and at Udde- 

 valla (Malm), and in the post-glacial beds of Norway 

 at various heights from the present level of the sea to 

 100 feet above it (Sars). Wood includes it (although 

 with a doubt as to the identity of the species) in his 

 1 Crag Mollusca/ from the Coralline formation at Sutton; 

 but his description shows that the outer lip is notched 

 within, a character which the recent shell does not pos- 

 sess. It inhabits Bohuslan, according to Loven, who 

 called it R. textilis of Philippi ; Malm dredged it in the 

 same district in 10-60 f., Danielssen at Christiansund- 

 in 40-60 f., M f Andrew in Nordland, and Sars at Tromso, 

 Ox fjord, and elsewhere in Norway in 10-50 f. ; Tasle 

 found it in Brittany < Martin has taken it in the Gulf 

 of Lyons, Mace at Antibes, Verany at Nice, Brusina in 

 Dalmatia, and M 'Andrew off Orotava, Canary Isles. 



Of this species, again, we have two sizes, a large and 

 small one. 



It appears to be the Turbo retiformis of Montagu (from 

 Walker's doubtful description and figure), R.puncturata 

 of Macgillivray, R. approxima of Brown, and Turritella 

 Dorvilleana of Leach. 



