PROSOBRANCHIATA. 261 
In all other respects the shells agree ; and I do not feel any doubt, therefore, as to the 
accuracy of the identification. 
With the Grignon specimens, I received some from Damery, in which the tubercles 
are thin and compressed, resembling small, oblique ribs ; they form a variety, probably 
not known to Deshayes at the date of his work above cited, and therefore not noticed 
by him. Our English shells present the thick rounded tubercles characteristic of the 
type, and from which the specific name was taken. 
Size.—My specimens have not attained the size of the French shells; of the 
largest the axis is 9-12ths of an inch nearly (18 millim.); the diameter 3°5-12ths of an 
inch nearly (7 millim.). 
Localities.—Stubbington. French: Grignon, Parnes, Courtagnon, Damery (fide 
Desh.) ; Lattainville (fide Graves). 
No. 182. Preuroroma Noposaria. £7 2. Edwards, Tab. XXIX, fig. 8 a, 4. 
P. testé turritd, tuberculo-costaté, spiraliter lineatd : spird acuminata, elevatd: anfrac- 
tibus convexis, ad humeros sub-angulatis ; marginibus posticis depressis, vie canaliculatis, 
ad suturam lined elevatd cinctis ; ultimo anfractu brevi, autice valde coarctato, in canalem 
brevem producto ; lineis spiralibus ewilibus, proeminentibus, sub-distantibus : aperturd 
ovata ; labro parum arcuato ; sinu lato, sub-semicirculari, anticd in margine collocato. 
Shell narrow, turreted, ribbed, concentrically lined: spire pointed, produced, 
much exceeding the last whorl in length: whorls convex on the sides, rather bluntly 
angulated at the ‘shoulders, and crowned with a row of small, oval-shaped, vertical 
tubercles, impressed by the concentric lines ; the posterior margins are depressed, very 
slightly furrowed, almost straight, and bordered round the suture by a single slender 
raised line ; the spiral lines are slender, very prominent, and rather distant. The last 
whorl is short, and somewhat suddenly contracted towards the front, and terminates 
in a short, narrowish canal. The aperture is ovate ; the outer lip slightly arched, and 
the sinus wide, nearly semicircular, and placed in the very front of the margin. 
I possess but an imperfect specimen of this species, but the characters are so 
distinct that it appears worthy of being recorded. 
Size.—Axis, 5-12ths of an inch ; diameter 2-12ths of an inch. 
Locality. Southampton. 
No. 183. Prevroroma unpata. Lamk. Tab. XXIX, fig. 11, a, 6. 
PLevRotoMA uNDATA. Lamk. 1604. Ann. du Mus., vol. iii, p. 169, No. 9. 
— — Lamk. 1822. Hist. nat., &c., vol. vii, p. 99, No. 14. 
--- — Desh. 1824-37. Descr. des Coq. foss., &c., vol. ii, p. 456; t. 63, 
figs. 11—13; t. 64, figs. 21—23. 
