332° MISS DONALD ON PROTEROZOIC GASTEROPODA _[ May 1902, 
Genus Lophospira, Whitfield.! 
This genus is thus described by R. P. Whitfield (Joc. cit.), 
‘Shells univalve. with elevated spires and strongly carinated or keeled 
volutions ; whorls closely coiled in the upper part, but often becoming discon- 
nected below from a too rapid descent of the coil. Central keel marking the 
position of a sinus or notch in the outer lip of the aperture. Axis usually 
minutely perforate when the whorls are not disconnected. Types: Murchisonia 
bicincta=M. Milleri, Hall, and M. helicteres, Salter.’ 
It has since been emended and divided into sections and sub- 
sections by Ulrich.’ I hope, in a future paper, to discuss this genus 
fully, and describe all the known British species. At present I am 
only describing two of the probably earliest representatives, and 
also the only one with which I have met showing the sinus in the 
outer lip. 
Lopuosprra (?) ANeULoctncrA (Salt.). (Pl. IX, figs. 4 & 4a.) 
Murchisonia angulocincta, J. W. Salter, 1859, Quart. Journ. Geol. Soc. vol. xv, 
p. 380 & pl. xin, figs. 9,10; J. Sowerby, 1867, ‘Siluria’ 4th ed. p. 532; J.J. Bigsby, 
mie ‘Thes. Silur.’ p. 157; R. Etheridge, 1888, ‘Foss. Brit. Is.’ vol. i (Paleozoic) 
p. ; 
Diagnosis.—Shell very elongated, slender, turreted, composed 
of about thirteen whorls. Whorls increasing gradually, strongly 
angular below the middle, slightly concave both above and below. 
There is a swelling immediately below the suture, and an angle or 
keel below the band on the body-whorl. Band situated on the 
strong angle below the middle of the whorl, prominent, rather 
convex. Lines of growth indistinct, apparently curving back to 
the band above, and forming a shallow sinus on the band itself, not 
seen below. Aperture subquadrangular. 
Remarks.—All the specimens of this species hitherto seen are 
much weathered. A small example in the Museum of Practical 
Geology, Jermyn Street, shows the surface best, but 1t is more or less 
indistinct. A portion of one of its whorls is figured (Pl. IX, 
fig. 4a), showing what appear to be the lines of growth, which give 
the band a somewhat crenulated appearance. If this be really the 
correct sculpture, this species can only have possessed a sinus in 
the outer lip, and not a slit. For this reason, and also because no 
well-authenticated species of Murchisonia have appeared so early, I 
refer it to Lophospira, Whitfield. 
Resemblances.—This species is quite distinct from all known 
British ones. It bears some resemblance to M. Catharina, Billings,* 
from the Quebec Group in Canada, in form, the great angularity of 
the whorls, and in the position of the angle below the middle of 
the whorls. 
Dimensions.—There are three specimens in the Museum of 
t Bull. Amer. Mus. Nat. Hist. vol. i (1886) p. 312. 
* Final Rep. Geol. & Nat. Hist. Surv. Minnesota, vol. iii, pt. ii (1897) 
pp- 960 & 962. . 
5 Geol. Surv. Canad. ‘ Palwoz, Foss.’ vol. i (1865) p. 231 & fig. 215. 
