Vol. 58.] REFERRED 10 MURCHISONIA AND PLEUROTOMARIA 329 
above and very obliquely forward below, curved on the band itself, 
indicating the existence of a deep V-shaped sinus in the outer lip. 
Aperture imperfectly known, inner lip slightly thickened. Base 
produced. Umbilicus closed. Sutures very oblique. 
Type, G. filosa, sp. nov. 
Remarks and Resemblances,—Ina former paper’ I referred 
to this group of shells as greatly resembling Hormotoma, regarding 
it as a subgenus, but I had not then met with any British speci- - 
mens, and therefore abstained from naming it. Goniospira is like 
Hormotoma in its elongated smooth form, and in the character of the 
sinus and the lines of growth. It differs in possessing more angular 
whorls, and in the band being prominent and slightly convex. 
From Lophospira it is distinguished by the band being less distinctly 
limited, and by the greater obliquity of the lines of growth. 
Dimensions.—The length varies from 23 up to possibly 
75 millimetres. 
Range.—This subgenus most probably ranges from the Ordo- 
vician up to the end of the Silurian System. The only known 
British representative is from the Middle Bala [Lapworth] of the 
Girvan district. Murchisonia Artemesia, Billings,’ from the Calci- 
ferous Group of Canada, which has a convex band, possibly belongs 
here, but the whorls appear less angular. Also M. attenuata, His.,° 
from the Silurian of Gotland, has the essential characteristics of this 
subgenus, although the angularity on the base is not so marked. 
GontosPira FrLosa, sp. nov. (Pl. VIII, figs. 6 & 64a.) 
Diagnosis.—Shell elongated, turreted, composed of more than 
eight whorls. Whorls increasing gradually, angular near the 
middle, slightly excavated above, flat below, with a strong angle on 
the base, which is hidden by the suture in the earlier whorls. The 
only ornamentation is a raised thread immediately below the suture. 
Band prominent, narrow, convex, situated on the angle. Lines of 
growth sharply defined, curving back to the band above, and very 
obliquely forward below, continuing across the band, and forming a 
V-shaped sinus. Sutures very oblique. Aperture longer than 
wide ; columella-lip slightly thickened. Base produced. Umbilicus 
closed. 
Remarks and Resemblances.—tThis species is represented 
at present by only one specimen in Mrs. Gray’s collection, which is 
remarkably well-preserved, and shows the lines of growth distinctly. 
As I observed in describing the subgenus, it bears most resemblance 
to Hormotoma: especially the earlier part of the spire, when the 
outer shell-layer is removed, obliterating the prominence of the 
band, which here appears level with the surface, having the lines 
of growth continuous across it from suture to suture. The smooth 
1 Quart. Journ. Geol. Soc. vol. lv (1899) p. 260. 
2 Geol. Surv. Canad. ‘ Paleoz. Foss.’ vol. i (1865) p. 345 & fig. 332. 
* Lindstrom, ‘Silur. Gastrop. & Pterop. Gotl.’ Kongl. Svensk. Vet.-Akad, 
Handl. vol. xix, No. 6 (1884) p. 130 & pl. xii, figs. 20-24. 
