MARSHALL: ADDITIONS TO "BRITISH CONCHOLOGY." 69 



Shetlands and Frerces, but nearest the latter group, in 62 f. and 510 f. 

 It is a Norwegian species, and was originally described by Herr Friele 

 from Bergen. The synonyms are Cyclostrema Levigatum G O. Sars, 

 and C. basistriatum and C. curvistriatum Brugnone. 



Specimens of M. costidatci Moll, have been dredged by Mr. Alfred 

 Brown off Silvercraigs, Loch Fyne, 12 f. ; and by myself at Lamlash 

 10 f. ; and Clyde t8 f. ; dead specimens and probably fossil. It is 

 well figured in Sowerby's Index. 



Circulus striatus Phil. — Bartra Island, co. Mayo ; and Portrush, 

 co. Antrim. 



Trochus helicinus Fab. — Groomsport, co. Down ; Portrush, 

 co. Antrim. 



Var. fasciata Jeffr. — Portrush ; East Sutherlandshire. 



T. grcenlandicus Chemn. — All the figures of this shell exhibit 

 four whorls, while different writers describe them as having four, five, 

 and six whorls. In reality, an adult specimen has six, the first two of 

 which are smooth and white, and the size is a quarter of an inch. 

 Jeffreys' figure is a bad one both in shape and execution, and different 

 from Sowerby's very good one. Forbes and Hanley give four capital 

 figures (as T. undulatus and var.), only one of which is adult and has 

 five whorls, the others being obviously immature or dwarfs, as the 

 annexed measurements indicate one-eighth of an inch, while the 

 authors describe it as one-fifth. 



Var. dilatata Jeffr. — Sutherlandshire (Baillie) ! but sculptured 

 as the type. 



Var. laevior Jeffr. — Skye, 30 f. This variety is usually smaller 

 than the type, but my Skye specimens are larger, and deep pink in 

 colour. 



T. cinctus Phil. — Extremely variable in sculpture. Not un- 

 common in some parts of the Atlantic. Jeffreys described a var. affinis 

 from the ' Porcupine ' expedition. 



T. magus L. — Very variable as regards height of spire and 

 convexity of whorls. Specimens from between tide-marks differ from 

 those which are dredged in being more depressed, and the whorls are 

 not so turreted nor so nodulous below the suture. Bucquoy, Daut- 

 zenberg, & Dollfus have named this form var. obsolete?, and a similar 

 form with a raised spire, which I have from Guernsey and Fowey, 

 is their var. producta. 



Var. alba Jeff. — Cobo Bay, Guernsey (Cooke and Gwatkin) ; 

 Herm, low water. A colourless form is not uncommon. 



Var. conica Marsh. (J. Conch., vol. 7, p. 250, 1893).— Heacham, 

 Norfolk (Mayfield) ! (This is the only record I know from the east 



