278 
DEVONIAN FAUNA. 
Size. — Height 20 mm., width 17 mm. 
Localities. — From Wolborougli there are three specimens in Mr. Vicary's 
Collection, and three in the Museum of Practical Geology. There are two in the 
Battersby Collection in the Torquay Museum, one of which, an extremely poor, 
almost unrecognisable specimen of the most elevated variety, is from Wolborough, 
and the other, equally poor, is apparently from Lummaton. 
Bemarhs. — These specimens vary so much in the height of their spire and style 
of ornamentation that at first I was much disposed to regard them as belonging 
to more than one species. The latter quality is, however, probably due to their 
state of preservation. A specimen of Mr. Vicary's is the only one which retains 
the external shell, and therefore the only one whose ornamentation can be relied 
on. The decortication of the other specimens has more or less destroyed their 
true ornamentation. 
In the above-named specimen the sinus-band is clearly shown, and hence it is 
clear that the species belongs to the genus Pleurotomaria. 
Affi,nities. — From TrocJms muUispira, Sandberger,^ which it resembles in the 
number of its whorls, it differs in the possession of spiral ridges, in the shape 
of the front of its mouth, and in the possession of a sinus-band. 
. 2. Pleurotomaeia subclathbata, Sandberger. PI. XXVII, figs. 9 — 11. 
1842. PiETTEOTOMABiA STJBCLATHRATA, Sandberger. In Neues JahrbucK f. Min., 
p. 391, pi. 8B, fig. 5a— c. 
1853. — — Sandberger. Verst. E.hein. Nassau, p. 198, 
pi. xxiv, figs. 10, 10 a — c. 
1857. TuEBO NANUS, Eichwald. Bull. Soc. Nat. Moscow, p. 164. 
1860. — — — Lethsea Rossica, p. 1138, pi. xliv, fig. 20. 
1889. Pleij-eotomaria subclathbata, Whidborne. Geol. Mag., dec. 3, vol. vi, 
p. 30. 
Description. — Shell of moderate size, turbinate, turrited, rather depressed, of 
about four volutions. Spire conical. Suture rectangular. Whorls narrow, 
slowly increasing, spreading somewhat flatly from the suture to the shoulder, then 
suddenly turning and becoming perpendicular for about an equal distance, and 
then curving rapidly inwards to form an obliquely flat base. Sinus-band situated 
on the shoulder, narrow, very concave, bounded by steep, sharp, prominent ridges. 
Ornament consisting of one similar spiral ridge near the suture, two or three similar 
equidistant ridges on the back below the sinus-band, and smaller decreasing 
and rather closer ridges on the base. Mouth sub-quadrate, transverse ? Inner 
lip arched. Umbilicus very small. 
^ 1853, Sandberger, ' Verst. Ehein. Nassau,' p. 218, pi. xxv, figs. 11, 11 a — c. 
