MARSH '^LL : ON THE BRITISH SPECIES OF BUCCINUM, FUSUS, ETC. 4I 



imagine its utility, nor why it is present in only half the specimens. 

 Jeffreys' dimensions are extreme ; the usual size is 4^-in by 2-in. A 

 dwarf form from the Doggerbank does not exceed 3-in. by i-i-in. 



F. TURTONi, Bean. — Aberdeenshire coast, 70 miles from land, in 

 40 f., and from trawlers (Simpson)! Peterhead, 43 f. ("Triton;" Exp.)! 

 East Shetland fishing-banks, from trawlers. This species lives in 

 muddy ground in deep water far from land, rare ; more often procured 

 by deep-sea fishermen than by the dredge. The colour is yellowish- 

 white under the epidermis, and occasionally the inside is more or less 

 tinged with purple ; epidermis rather thin, deciduous, ranging from 

 light-brown to olive-green, and frequently stained with ferruginous 

 deposit. Round the periphery the spiral riblets are more prominent 

 and irregular, and these sometimes develope into ridges or carinations 

 (as in F. antiquu!< rar. carinata), thus making the whorls more or less 

 angular at that part. The operculum is large, elongated, and obliquely 

 triangular (but varies greatly in length and width), dark horn-colour, 

 highly glossy, closely wrinkled with semi-circular striations, and having 

 impressed lines (variable in number) radiating from the nucleus. 



This species is subject to more extreme variation than is generally 

 supposed, and I regard it as by far the most variable of the genus, 

 while the differences between the male and female forms are more 

 than usually apparent. My smallest adult specimen, from the 

 Shetlands, is only 3-in by i j-in., while the other extreme is represented 

 by examples exceeding 5-4-in. by 2i-in., and there is every intermediate 

 gradation of length and breadth. The whorls also are of every degree 

 of convexity, and the aperture is especially variable according to age, 

 as after it has reached maturity the outer lip is added to and reflected. 

 The shell of the male, correctly figured by Sowerby and Jeffreys, has 

 a comparatively small body-whorl and an elongated spire, and rarely 

 exceeds 4|-in. by li-in. The young of this up to 2-in. in length 

 present a very droll appearance, being all spire. An extreme example 

 of this male form from the Shetlands, having the spire abnormally 

 elongated, now in the collection of Mr. James Simpson of Aberdeen, 

 has been named (in MS.) var. aftentucifa. The shell of the female, 

 well figured by Forbes and Hanley (^) is larger and broader through- 

 out, the spire is not nearly so attenuated, the last whorl is very much 

 larger and swollen, and the shell attains 5j-in. by 2i-in. The young 

 of both forms are easily distinguished at all ages, and the adult have 

 each the same number of whorls, yi. 



Bean founded this species on a specimen found in a Scarborough 

 fishing-boat, but I have not been able to refer to his original descrip- 

 tion and figure to see which of these two forms is the type. (Jeffrey's 



