MURCHISONIA. 59 



PI. (Gyroma) Baconnierensis, (Ehlert,^ has a deeper suture-line, a smaller and 

 less conical spire, a coarser ornament, and a concave sinus-band. 



PL interstrialis, Phillips' differs in the character of its sinus-band and other 

 particulars. 



4. Pleurotomaeia, sp. PI. V, fig. 9 ; and PI. VI, fig. 8. 



Description. — Shell minvite, very elevated, of several rather broad and slowly- 

 increasing, convex whorls. Suture deep. Surface ornamented with several high, 

 unequal, subacute, concentric ridges, which are crenulated by more numerous 

 elevated, rounded, transverse threads, arching backwards from the upper suture, 

 and very strong on the sinus-band, which appears to be elevated, rounded, and 

 situated at or about the centre or wider part of the back in the body-whorl. 



Size. — Length about 4 mm. 



Localities. — In the Porter Collection are two imperfect specimens from Pilton. 



BemarJcs. — It appears to me that these specimens are more likely to belong 

 to some very lofty species of Pleurotomaria than to Murchisonia, but their state 

 of preservation is too imperfect to permit any definite opinion to be formed at 

 present upon them. 



2. Ge7ius — MuECHisoNiA, Phillips, 1841. 

 1. Murchisonia anglica, d'Orhigny. PI. VI., fig. 14. 



1841. MuECHisoNiA ANGTTLATA, PMlUps. Pal. Foss. (not Geol. Torks.), p. 101, 



pi. xxxix, fig. 189. 

 1849. — AifGLiCA, d'Orhigny. Prodrome, vol. i, p. 76. 



1891. — TXTEBINATA (pars) ? Whidborne. Dev. Fauna, voi, i, p. 307. 



Description. — Shell small, elevated, turrited, of comparatively few whorls. 

 Spire conical, exceeding the body-whorl in height. Whorls very broad, convex, 

 arching out obliquely from the suture with a gentle curvature to the widest part, 

 which is three-quarters the way down, and then rapidly curving in to the lower 

 suture. Sinus-band broad, elevated, concave, angular, situated near the base of 

 the whorl. 



1 1887, (Ehlert, 'Bull. Soc. Etud. Sci. Angers,' Ann. 1887, p. 32, pi. viii, figs. 7—7 c. 



2 1836, Phillips, ' Geol. Yorks.,' vol. ii, p. 227, pi. xv, figs. 10, 10 a. 



