Vol. 58.] REFERRED TO MURCHISONIA AND PLEUROTOMARIA. 331 
on the band itself, indicating a fairly deep sinus. Sutures deep. 
Aperture imperfectly known, “apparently sub-ovoid. 
Remarks and Resemblances.—So far, only two specimens 
of this species are known to me, and these are in Mrs. Gray’s 
collection. ‘They are both more or Jess crushed and flattened by 
pressure. The spiral angle of the higher whorls of the largest 
individual is smaller than that of the rest of the spire; whether this 
is a natural condition, or caused by pressure, it is impossible to say : 
it may perhaps be the result of both. This shell (Pl. VIII, fig. 8) 
measures 16 millimetres in length and 7°5 mm. in width; it is partly 
embedded in the matrix. The other (Ble VA figs 7) has six whorls 
ina length of 138 mm., the width measuring 6 mm. in one direction, 
and 4:°5 mm. in the other; it is disengaged from the matrix. The 
lines of growth are strong and well marked on part of the body-whorl. 
This is quite distinct from all previously described British species. 
Locality and Horizon.—Shalloch Mill (Ayrshire), in rocks 
of Middle Bala age | Lapworth ]. 
TurRRIToMA (?) PINGUIS, sp. nov. (Pl. IX, figs. 1-3.) 
Diagnosis.—Shell conical, or somewhat pyramidal. Whorls 
about nine, increasing rather rapidly, smooth, flat above, angular 
at the periphery. Band generally flat, but sometimes slightly 
raised and convex on the last whorl, limited by a groove on each 
side, situated on the periphery, near the middle of the body-whorl, 
just visible above the suture on the penultimate whorl, wholly or 
partly hidden on the earlier whorls. Lines of growth strong, 
sweeping obliquely back to the band above and still more obliquely 
forward below, forming crescents on the band, and indicating the 
existence of a deep sinus in the outer lip. Sutures deep. Base 
flattened and very slightly convex. Umbilicus closed. Aperture 
imperfectly known. 
Remarks and Resemblances.—This shell much resembles 
T’.. (?) polita, but differs in being of greater size, and in the whorls in- 
creasing more rapidly, thus rendering the shell shorter in comparison 
to the width. Also the body-whorl appears more angular, and the 
base flatter and less produced. In the conical spire and flatness of the 
whorls it is like Huconia Htna (Billings)' and LE. Ramsay (Billings) * ; 
but it is distinguished from both by being more elongated, having 
the base less flattened, the band on the periphery, the lines of 
growth forming a deeper sinus, and the absence of an umbilicus. 
Dimensions.—There are eight specimens in Mrs. Gray’s col- 
lection. The largest has five whorls preserved in a length of 
23 millimetres, the width measuring 13 mm. ‘The specimen figured 
in Pl. IX, fig. 1, also has five whorls, and measures 22 millimetres 
in length and 13 mm.in width. Another individual, if entire, would 
consist of about nine whorls in a length of 13 millimetres. 
Locality and Horizon. —Thraive Glen, in rocks of ies 
Bala age { Lapworth]. 
1 Geol. Sury. Canad. ‘Palioz. Foss.’ vol. i (1865) p. 226 & fig. 210. 
* *Canad. Nat. & Geol.’ vol. iv (1859) p. 851 & figs. 5 & 4. 
