64 MISS J. DONALD ON THE GENFS ACLISINA. [Feb. 1 898, 



difference in ornamentation and by the whorls being less convex 

 and higher. 



I know of only one specimen, which is in the collection of 

 Dr. John Young. It is imperfect, both apex and base being broken ; 

 the eight and a half whorls which remain measure 7 mm. in length; 

 width = 1 1 mm. 



Locality and Horizon. — Crawfield Quarry, Beith. Lower Lime- 

 stone Series {cV). 



ACLISINA PAEVTJLA, sp. UOV, (PI. Y, figS. 1, 2, 2 a, 6 & C.) 



Description. — Shell conical, elongated, composed of about ten 

 whorls. Apex blunt, protoconch consisting of one smooth revolution 

 coiled on the same plane as the rest of the spire, and adhering ta 

 the highest whorl of the conch. Whorls convex, wide in proportion- 

 to the height, ornamented by six or seven raised threads separated' 

 by nearly equal spaces ; uppermost thread sometimes absent; one or 

 two additional threads on the body-whorl. Sutures slightly inclined. 

 Aperture subovoid. Columella simple, sKghtly thickened. Base 

 convex, imperforate. 



Resemblances. — This species greatly resembles A. pusilla^^mt it 

 differs in having a greater spiral angle, and in having fewer and 

 stronger ornamenting threads. It may be distinguished from 

 A. elongata by having fewer threads, and in the protoconch adhering 

 to the spire instead of being raised from it. 



Locality and Horizon. — There are five specimens from Law in the 

 collection of Mr. Bennie, only one of which has the protoconch entire 

 (PI. Y, figs. 2a, b & c). The largest consists of ten whorls: its- 

 length=3| mm. That figured (PI. Y, fig. 1) is from Crawfield, and 

 was given to me by Dr. Young ; it possesses nine whorls, whose 

 length = 3 mm., width = 1 mm. From the Lower Limestone 

 Series (d^). 



? AcLisiNA suLCATULA, M'Coy. (PL Y, fig. 3.) 



Loxonema sulcatula, F. M'Coy, 1844, ' Syn. Char. Carb. Foss. Irel.' p. 30 & pi. v, 

 fig. 6; H. G. Bronii, 1848, 'Index Palseont.' p. 670; J. Armstrong, J. Young, & 

 D. Robertson, 1876, 'Cat. W. Scot. Foss.' p.56; J. J. Bigsby, 1878, ' Thes. Dev.- 

 Carb.' p. 325; R. Etberidge, 1888, ' Foss. Brit. Is.' vol. i, Palaeozoic, p. 300. 



Description. — Shell elongated, conical, composed of seven or eight 

 convex whorls, increasing at a moderate rate. Whorls ornamented 

 by five strong spiral threads, with numerous finer additional threads 

 below on the body-whorl. Sutures deep. Aperture subovoid. 

 Columella simple, slightly thickened. Base convex. 



Remarhs. — This species is represented only by three more or less 

 imperfect external casts, and the figures are drawn from wax im- 

 pressions, M'Coy refers it to Loojonema, but it has not the charac- 

 teristic longitudinal ribs of that genus nor the adpressed whorls ; 

 the spiral threads also serve to distinguish it. He describes it as 

 having ' about ten equal spiral sulci,' but the best-preserved specimens' 

 only show four or five, which are separated by the same number of 

 strong raised threads. One specimen, of which the surface is much 



