336 MISS DONALD ON PROTEROZOIC GASTEROPODA [| May 1902, 
and situated on the periphery. From Ptychomphalina, Bayle’ it is 
separated by having less convex whorls, and in the slit probably 
being shorter. In Bembewia, Géhl.’ the form is more turriculated, 
the band higher above the suture and situated on the periphery; 
also the lines of growth sweep backward to and forward from the 
hand less obliquely. Though the umbilical region is imperfectly 
known, it does not appear to have the wide umbilicus of Mourlonia, 
de Kon.* 
Dimensions.—The length of the type=11 millimetres. 
Range.—The only species at present known is from the Llan- 
deilo Formation. 
PALMOSCHISMA GIRVANENSE, sp. noy. (Pl. IX, figs. 11 & 11a.) 
Diagnosis.—Shell depressed-conical, composed of more than four 
whorls. Whorls increasing rapidly, smooth, slightly angular at the 
periphery, flat or rather concave above, convex below. A fine thread 
immediately below the suture constitutes the only ornamentation. 
Band a little above the middle of the body-whorl, but very low 
down on the penultimate whorl, being about half its width above 
the suture, flat or slightly concave, bounded by a strong thread on 
each side, with another thread between, somewhat nearer the upper 
than the lower limit, and becoming much fainter on the latter half 
of the body-whorl, the lower margin coinciding with the periphery. 
Lines of growth sloping rather obliquely back above, forming 
crescents on the band, and advancing with a moderately convex 
curve below. Slit in the outer lip short. Base convex. Aperture 
imperfectly known. Umbilicus probably closed. 
Remarks.—At present there is but one specimen known of this 
species, which is in the collection of Mrs. Gray. It is remarkable 
for being the earliest British representative of the Pleurotomariide 
with which I have met possessing the slit in the outer lip preserved, 
the end and greater part of the sides being intact. 
Resemblances.—This_ species greatly resembles Hotomaria 
labiosa, Ulrich,‘ in form, but is distinctly separated from that species, 
and from all other members of the genus, by possessing a slit in the 
outer lip, and a thread near the middle of the band. It bears also 
a certain general likeness to figures of Pleurotomaria elliptica, His.’ 
Prof. Lindstrom kindly lent me a specimen of that species from the 
1 P. Fischer, ‘Man. de Conchyliologie’ 1885, p. 850. After a vain search 
for the original description of this genus by Bayle, I wrote to ask Dr. H. Fischer 
whether he could throw any light on the subject. As far as he can tell, his 
father was the first to publish the description of the genus, the name of which 
was written in manuscript by Bayle on the labels of the following species in 
the Ecole des Mines, Paris—P?. carinata, Sow. (Visé), Pt. conica, Phill. (Visé), 
and Pt. striata, Sow. (Visé). The date of the genus given by Fischer is 1885, 
and that was the year in which p. 850 was published. 
2 Bull. Soc. Etudes Sci. Angers, 1887 (sep. cop.) p. 24. 
3 Ann. Mus. Roy. Hist. Nat. Belg. vol. viii, pt. iv (1883) p. 75. 
4 Final Rep. Geol. & Nat. Hist. Surv. Minnesota, vol. iii, pt. ii (1897) p. 1003 
& pl. lxix, figs. 15-17. 
° *Tethea Suecica’ 1837, p. 35 & pl. xi, fig. 1. 
ae Ae Re 
