- 
PROSOBRANCHIATA. 327 
No. 249. Borsonita Braritzana. Rowault. Tab. XXXIII, fig. 11, a, 4. 
Borsonta Brarirzana. Row. 1848. Bull. de la Soc. Géol. de France, 2¢ série, vol. vy, p. 207. 
— Pauensts. Rou. 1848. Idem. 
Corpieria BrarirzaAna. Rou. 1848. Desc. des Foss. du térr. Eocene, des Env. de Pau 
(Mem. Soc. Géol. de France, 2d series, vol. iii, p. 488, 
tabyeli7apuSs (0, 5/0, a). 
PLEUROTOMA cuURVICosTA. Sow. (non Lamk.) 1850. Dixon’s Geol., &c., Sussex, p. 183, 
tab. 7, fig. 17. 
— _- Morris, 1854. Cat. Brit. Foss., p. 270. 
FascIoLaRIa BIPLICATA. Sow. 1850. Dixon’s Geol., &c., Sussex, p. 134, t. 5, fig. 7. 
— — Morris, 1854. Cat. Brit. Foss., p. 248. 
B. testd elongato-fusiformi, turritd, longitudinaliter nodoso-costatd, spiraliter lineata : 
spiraé acuminatd, elevata, in longitudine aperturam paullo superanti: anfractibus conveais, 
postice canaliculatis ; costis latis, rotundatis, brevibus ; lineis spiralibus crebris, filiformibus : 
apertura oblongo-ovatd, antice in canali lato brevique exeunte ; labro sub-recto, in margine 
sinuato ; sinu lato, mediocriter profundo, semicirculari ; columella sub-cylindricd, biplicata. 
Shell elongated, fusiform, ribbed, and spirally lined; the spire pointed and 
elevated, somewhat exceeding the aperture in length. The whorls, eight or ten 
without the pullus, are convex, and bluntly angulated at the shoulders, and the pos- 
terior margins slope gently backwards and are concentrically furrowed. The longitu- 
dinal ribs are distant, very broad, rounded, and somewhat swelled, so as to become 
almost nodulous, on the shoulder; the concentric lines are numerous and thread-like, 
even and regular on the posterior margins and shoulders of the whorls ; elsewhere 
they are unequal, more prominent lines alternating with the slender lines, and all are 
more or less strongly decussated by the lines of growth. The aperture is of an oblong 
ovate form, and terminates in front in a very wide and short, but distinct, canal; the outer 
lip is nearly straight, and presents a wide but not very deep sinus, placed in the posterior 
margin of the whorl; the columella is somewhat cylindrical and nearly straight, and 
presents, a little behind the middle, two slightly oblique, narrow folds, which do not 
extend to the front of the columella, and which, consequently, are scarcely visible 
unless the outer lip is broken off. - 
The specimen figured and described by Mr. Sowerby (loc. cit.) as P. curvicosta, 
forms part of my collection ; at that time the aperture was closed by the matrix, and 
the columellar folds, therefore, were not detected. These folds have since been ex- 
posed to view, and there cannot be now any doubt of the identity of P/ewrotoma cur- 
vieusta (Sow.) and Fusciolaria biplicata. 
The shells from Bos d’Arros, described by Rouault, apparently do not attain so 
large a size as our English shells; in them the last whorl is longer, apparently, than 
