~ PROSOBRANCHIATA. 305 
No. 230. Pieurotoma curta. Ff. #. Edwards. Tab. XXXJ, fig. 2, a, 6. 
P. testé parva, subfusiformi, turritd, tuberculo-plicatd, undique transversim sulcata : 
spira sub-conicd, acuminata ; anfractibus conveaiusculis, ad humeros sub-angulatis, tuber- 
culatis ; postice concavis, granulato-marginatis ; ultimo anfractu repentissime coarctato, in 
canalem brevem producto ; tuberculis sub-distantibus, oblongis, bifurcis, plicas duas arcuatas 
formantibus ; sulcis transversis confertis, supra canalem perspicuis, ceterum fere obsoletis : 
apertura obovali ; labro leviter arcuato ; sinu lato, brevi, sub-trigono, ad humerum collocato. 
Shell small, rather fusiform, turreted, tuberculous, and concentrically furrowed : 
the spire, somewhat conical, pointed, and moderately elevated, being of equal length 
with the aperture. The whorls are very slightly convex, and bluntly angulated at 
the shoulders, where they are furnished with a row of short, vertical, oblong tubercles, 
which bifurcate in front, and are produced into two narrow, oblique, unequally arched, 
fold-like costellz, which extend to the beginning of the canal; the posterior margins 
are rather deeply channeled and bordered round the suture by a single row of small, 
round granulations, corresponding with the tubercles on the shoulders ; the last whorl 
is suddenly and much contracted towards the front, resembling that of P. coarctata ; 
the transverse furrows are numerous, perspicuous over the canal, but elsewhere 
nearly obsolete. The aperture is rather widely oval; the outer lip moderately arched ; 
and the sinus, which is placed on the shoulder, is wide, rather deep, and semi- 
elliptical in form. 
I know only the figured specimen of this species, and this is probably an imma- 
ture individual. It presents a close resemblance to P. dracheia, with which, without 
a careful examination, it may be easily confounded. On comparing the two shells, 
however, it will be seen that in the present species the spire is more regularly tapering, 
the posterior margins a little more depressed and more deeply channeled ; the granu- 
lations round the suture smaller, and placed opposite to the tubercles on the shoulders, 
and the body whorl much more contracted. These differences, with the bifurcated 
tubercles, the different character of the transverse ornamentation, and especially the 
shape and position of the sinus, are sufficient to entitle the present shell to specific 
distinction. 
Size.—7-24ths of an inch; diameter, 3-24ths of an inch. 
Locality— Alum Bay (Strat. No. 29, Prestw.) 
No. 231. Pxrevrotroma purtta. F. #. Edwards. Tab. XXXI, fig, 15, a, 4. 
P. testa clongato-fusiformi, spiraliter granoso-lineatd : spird elevatd, obtusiusculd, sub- 
conicd ; anfractibus convexiusculis, ad humeros unicd serie tuberculorum brevium ornatis ; 
39 
