172 JOURNAL OF CONCHOLOGY, VOL. 15, NO. 6, APRIL, I917. 



this from a form of O. acuta which has a shorter spire, convex w^horls, 

 and narrower base ; the latter is identical in contour, but more solid 

 and not so glossy. Jeffreys' figures are too conical and the whorls 

 too convex (the shell is always more oblong), while Sowerby's is an 

 exaggerated copy of this, and I have already noted their too con- 

 spicuous tooth and umbilicus. 



O. acuta var. gracilis Marsh, is the O. acutula of Monterosato. 



O. COnspicua Aid. — Alderney (Marquand) ! Falmouth igf., a 

 slender variety; off Loch Ryan 25f., off Ailsa Craig 75f., Mull of 

 Cantire 25f , Dornoch Frith, a slender variety. This is less rare at 

 Scilly than elsewhere, but they are much smaller and more slender, 

 and not easily separable from O. imidentata. 



O. turrita var. striolata Aid. — Alderney (Marquand)! Caldy 

 Island. 



var. nana Marsh. — Off Loch Ryan 25f. 



O. plicata Mont. — Alderney (Marquand) ! All the records from 

 the Clyde are unreliable. 



var. carinata Marsh. — Torbay, one specimen only, but remark- 

 able in having two carinations round the periphery. 



O. insculpta var. Isevissima G. O. Sars. — Lismore 6f., Glenelg 

 3o-9of, Loch Liver 25f., Scalloway i2f. 



var. tumida Jeff. — Off Arran 65f, Scalloway in W. Shetlands 



I2f 



O. diaphana Jeff. — Off Fair Isle (Simpson) ! Shetland-Faroe 

 Channel. After a careful comparison, I ascribe to this species the 

 O. dilucida of Monterosato. 



O. warreni Thomps. — Alderney (Marquand) ! Achil Island ; 

 Benbecula Sound lof. Also south of Syracuse 4of. ('Newport') ! Vigo 

 Bay 2of (' Porcupine') ! Tripoli coast 4o-i2of. ('Shearwater ') ! 

 var. intermedia Marsh. — Tenby and Caldy Island. 



The type-form occurs in the Minch and Shetlands with var. 

 zetlandica Marsh. I consider O. scafidens (Brugno. MS.) Monts. to 

 be this species, as also 0. exilissima Brus. = 6>. semiornata De Fol. 



O. obliqua Aid. — Not "Alderney (Marquand)," which was an 

 error for O. ivarreni. Also Adventure Bank i2of (' Shearwater ') ! and 

 92f. (' Porcupine ') ! 



O. dolioliformis Jeff. — Great Yarmouth (Beckett); Caldy Island. 



O. clathrata Jeff. — Straits of Korea 2of. (' Sylvia ') ! 



O. indistincta Mont.— This species has not hitherto been recorded 

 from any of the Channel Islands, except by Jeffreys, who cites 

 "Guernsey." I have never met with it, and it is not to be found in 

 the Jersey or Guernsey Museums, nor in the Lukis collection ; neither 



