MARSHALL: ADDITIONS TO "BRITISH CONCHOLOGY." 291 



having no tooth or fold, that is only so outwardly and in the perfect 

 shell ; for when the lip is broken away a small though distinct tooth 

 is readily discernible. Jeffreys' figure is correct in its outlines, but 

 otherwise does not tally with his description. He says the suture is 

 wide and deep and that there is no tooth, characters which his figure 

 repudiates. Forbes and Hanley's figure is a good one, and Sowerby's 

 just the thing. Clark mixed up this species, which he had not seen, 

 with the next. Though a good malacologist, he was a poor concho- 

 logist, and from his habit of exalting the former study and depreciating 

 the latter, he made some amusing blunders, not all of which by any 

 means are to be found in his work. An exceedingly small variety, 

 from the Tripoli coast, 120 f., is only «V i ncn l° n § by half that width. 



O. indistincta Mont. — In fine sandy ground from Guernsey to 

 Shetland, 4 to 72 fathoms (the Minch). 



This is a most variable shell as regards size, contour, proportions of 

 the whorls, and suture. The lower whorls are usually more convex 

 than the upper, with a correspondingly deeper suture, and the longi- 

 tudinal ribs on the last whorl are often finer and more numerous 

 proportionally. Some specimens are very much like the more slender 

 forms of the next species (O. interstinctd) in shape, and have 

 straighter and coarser longitudinal ribs, but the absence of a tooth 

 will always mark it off from that species. Collectors, however, often 

 experience some difficulty in separating the two species, for reasons 

 given in my account of O. interstincta. Shetland produces the 

 coarsest, and Portrush the finest sculptured specimens, there being a 

 marked contrast between the two. It is not found at Jersey, and is 

 scarce in the other Channel Islands, but is not otherwise rare except 

 in a living state. A rare form from the Minch, coarsely sculptured, 

 has the peculiar outline of O. innovata, and another form is tubular 

 and compressed. Specimens of the dimensions given by Jeffreys are 

 rare ; one from the Minch is one-fifth, and one from Babbacombe is 

 one-fourth of an inch, but these are exceptional. Curiously, enough, 

 the Minch also produces a dwarf form from 53 fathoms, a similar 

 dwarf also occurring in Torbay in 6 fathoms. Although described as 

 " never furnished with a tooth," specimens possessing that character 

 have been recorded by General Stefanis from the Bay of Naples, and 

 by Professor Stossich from the Adriatic. The var. brevior has a 

 shorter spire and longer body-whorl, with identical but more delicate 

 sculpture, but it is not more convex. 



Var. minima n. var. — More slender proportionally, and very 

 much smaller ; sculpture finer, as in var. brevior, and easily worn off 

 in dead specimens. L.o - o7in.; B. 0*025. Guernsey 18 f.; Torbay 12 f.j 

 Southport ; Dornoch Frith. Also Adventure Bank, Mediterranean, 

 92 f. This has the outlines of a small and slender O. nivosa. 



