424 GASTEROPODA OF THE INFERIOR OOLITE. 
wrinkles on the posterior areas are, also, strongly developed,—a feature which is 
emphasised in d’Orbigny’s figures, but is probably of no greatimportance. Morris 
(‘ Quart. Journ. Geol. Soc.,’ vol. ix, p. 326) quotes Pl. reticulata, Desl., with a 
query, from the Ponton beds. 
365. PLEUROTOMARIA TEXTILIS, Deslongchamps, 1848. Plate XXXVI, fig. 8; 
including Pl. scalaris, Deslongch., fig. 9. 
1848. PLEUROTOMARIA TEXTILIS, Deslongchamps. Vol. cit., p. 68, pl. ix, fig. 2. 
1850. — — — D’Orbigny, Prod., i, p. 268. 
1854. _- -- —_ D’Orbigny, Terr. Jur., vol. ii, 
p- 492, pl. ecexci, figs. 6—10. 
1873. -— -- — Tawney, Dundry Gasteropoda, 
p- 53, (45). 
Syn. or var. — ScALARIS, Deslongchamps. Vol. cit., p. 66, pl. vii, fig. 4; 
pl. viii, figs. 1, 2,8; pl. ix, 
fig. 1. 
Bibliography, Sc.—Not without hesitation Deslongchamps concluded to 
separate Pl. tevrtilis and Pl. scalaris, though doubting the validity of the latter 
species. Finally he left it an open question. D’Orbigny recognised three species 
in this group, viz. Pl. textilis, Deslongch. (‘ Terr. Jur.,’ vol. ti, p. 492, pl. ecexci) ; 
Pl. strigosa, V Orb. (vol. cit., p. 504. pl. eeexevi); and Pl. subscalaris, d’Orb. (vol. 
cit., p. 505, pl. ceexevii). 
For the present I am content to regard the scalaris section of this group as 
representing megalomorphic forms of P/. textilis, which must be accepted as the 
specific name. 
Description (medium size = PI. tevtilis) : 
Height : : : . . 60mm. 
Basal diameter : ; : . 48 mm. 
Spiral angle . : ; 56°. 
Shell conical, turrited, not umbilicated. Spire regular. Whorls (about nine) 
angular and bicarinate or subbicarinate, according to the greater or less 
prominence of the basal rim. The whorls increase by steps, and in some cases 
are rather undercut; sutures close. In well-preserved specimens the ornaments 
of the apical whorls are seen to be reticulate, but in the later whorls spiral 
ornamentation alone prevails. 
The sinus-band is nearly median, large, round, and prominent ; and apparently 
without ornament other than curved growth-lines ; it is situate at the angle, and 
constitutes the greatest salience of each whorl, being more especially conspicuous 
