TURBO. 345 
although evidently not precisely what our author had before 
his eyes (for it is said to be “ex albo et roseo variegatus,” and 
not “grisea”’), nevertheless presents the general contour of it. 
In the tenth edition of the ‘Systema’ “ Bonan. Recreat. t. 118” 
was cited, a figure subsequently and more correctly referred by 
our author, on the constitution of the Buccinum subulatwm in his 
twelfth edition, to that species ; for this reference ‘“‘ Seb. Mus. iii. 
t. 56, f. 32,” was substituted in the last edition, manifestly quoted 
from the engraving exhibiting some appearance of a margin at 
the base of the whorls; but neither this nor any other represen- 
tation of a Turritella in the older writers exhibits the peculiar 
features of the specimen. We have consequently given a repre- 
sentation of the Linnean type (plate 3, fig. 2), by the accurate 
hand of Mr. Sowerby, junior. Although the shell is by no 
means a’ common form of the Turritella umbricata of authors 
(I regard Kiener, pl. 9, f. 2, a, as the normal state), I feel 
tolerably sure that it is only a slender variety of it. Where 
not wholly bleached—and a coating of dirt has fortunately pre- 
served in patches the pristine colourimg—it exhibits the brown, 
cloudy markings, and even faint traces of the minute articulation 
which distinguish that species, but almost the entire surface is 
so blanched (it has turned grayish or squalid white) that the 
expression “ grisea’ was not inapplicable to it. There appear 
to have been about sixteen whorls, of which two or three are 
now gone, all rather densely girt with delicate raised spiral 
strie. The earlier volutions are nearly flat, and much broader 
below than above; they display a rather coarse subcentral ele- 
vated stria, in addition to the somewhat imbricating basal belt, 
from whence the species derives its appellation. This belt at 
first appears as a sharply prominent carina; then, as it enlarges 
upon the lower whorls, it becomes obtuse and swollen. Upon 
the last two or three volutions a faint spiral prominence arises 
not far from the profound suture, and the middle portion of the 
surface becomes slightly retuse. The aperture is too broken to 
be spoken of with confidence, but, judging from the shortness of 
the columella and the direction of the lines of growth upon 
the outer lip, was, in all probability, of a rounded subquadrate 
form. 
