fl. Gb. HE. (A 24-570. (Er. KUL -~*K 6), BOO. 
PROSOBRANCHIATA. 941 
No. 162. Pxrevroroma 1nnExa. Solander. Tab. XXVIII, fig. 1, a—e. 
Murex InNeExts. Sol. 1766. Brand. Foss. Hant., p. 19, fig. 30. 
PLEUROTOMA INNEXA. Forbes. 1856. Tert. Fluv. Mar. Format., &e.; Mem. Geol. Surv., 
p. 154, t. 5, fig. 5. 
P. testé elongato-fusiformi, reticulato-crenulatd: spird sub-conicd, elevata: anfractibus 
viz convewis, lineas elevatas concentricas, et costellas longitudinales, sese decussantes, 
gerentibus ; marginibus posticis angustis, spiraliter sulcatis, ad suturam granulatis ; ultimo 
anfractu in canali patulo, per-brevi, exeunti; costellis acutis, usque ad basin tendentibus, 
arcuatis, tuberculatis: aperturdé oblongo-ovali, angustd ; labro aliforme, intis nonnunquam 
obscure denticuluto ; sinu lato, rotundato, in margine collocato ; labio angusto, incrassato. 
Shell elongated, fusiform, and ornamented with concentric and longitudinal raised 
lines, nearly equally prominent, and which, from their decussation, present the 
appearance of fine network. The spire is thick, nearly conical, and much elevated, 
almost equalling two thirds of the entire length of the shell. The whorls, eight or nine, 
exclusive of a pointed pullus of three volutions, are short, very slightly convex, nearly 
flat-sided ; the posterior margins are very narrow, and present a more or less shallow 
“transverse furrow; they are thickened on the edge of the suture, which is bordered 
by a single row of small, round, or somewhat oblong, granulations. The longitudinal 
ribs, which are narrow and sharp, extend from the marginal granulations to the very 
front of the whorl, and are rather strongly curved over the middle ; in general the 
ribs are a little more prominent than the concentric lines, and are thickened at the 
points of decussation, like the knots of a net, forming rows of small tubercles, the 
last of which, immediately in front of the margin, is more prominent than the rest. 
The concentric lines are irregular, close-set at the base, distant over the front of 
the whorl, and become more or less crowded as they approach the posterior margin. 
The aperture is of a narrow, oblong-ovate form, and terminates in a short, wide canal, 
rather deeply notched in front; the outer lip is much arched, sharp at the edge, 
thickened within, and presents three or four thick, tooth-like callosities, of which the 
posterior one in front of the sinus is large and prominent; the inner lip is narrow 
and thickened ; the columella is slightly curved, and bears in front a small crest ; 
the sinus is rounded and wide, occupying the whole width of the margin. 
The figure of this shell, given by Brander, is not executed with the felicity which 
usually characterises that author’s work, and to this circumstance, probably, is to be 
attributed the difficulty which the Continental writers have had in identifying the 
species. Thus Lamarck and, after him, Deshayes, referred P. inzexa, although with 
doubt, to P. wndata (Lamk.), from which species, however, it is easily distinguished 
31 
