268 ]vriss jane donald o'^ the geneea [^^ay 1899, 



and 23 mm. in width. It occurs in grey calcareous slates at 

 Kilbride, Cong. M'Coy states that this species is not uncommon, 

 at the former locality, but is rare at the latter. 

 H r i z n. — In rocks of Wenlock age. 



HoRMOTOMA siMiLis, sp. nov. (PI. XXII, fig. 6.) 



Description. — Shell elongated, turreted, composed of more than, 

 three whorls. Whorls slightly convex, smooth, with the exception 

 of a thread at the suture. Band level with, or rather depressed 

 below the surface, situated below the middle of the whorls of the 

 spire, and near the middle of the body-whorl, but slightly defined 

 by an indistinct thread on each side. The lines of growth curve 

 very obliquely forward from it below, and are not well seen above. 

 Aperture imperfectly known, apparently longer than wide. 



Eesemblances. — This species appears to be intermediate 

 between H. Grijffithi and H. articulata. It resembles the first in 

 general form, so far as can be judged, considering that the specimens 

 of both species are greatly compressed ; but it is rather smaller, and 

 the band is situated much lower down on the whorl. From the 

 latter it is distinguished by its greater size, the lower position of 

 the band, and its less convex whorls. 



Locality and Horizon. — There is only one specimen 

 (PI. XXII, fig. 6) in the Fletcher Collection in the Woodward ian 

 Museum, Cambridge, from the Lower Ludlow of Dudley. It is 

 broken and much flattened by pressure. The fragment consists 

 of only the three lower whorls, which measure 29 mm. in length 

 and 15| mm. in width. 



HoRMOTOMA ARTICTJLATA (SoW.). (PI. XXII, figS. 7 & 8.) 



Pleurotoma articulata, J. Sowerby, 1839, 'Sil. Syst.' p. 612 & pi. v, fig. 25. 



Murchisonia articulata, A. d'Archiac & E. de Verneuil, 1841, Bull. Soc. geol. 

 France, vol. xii, p. 160 ; F. M'Coy, 1846, ' Syu. Silur. Foss. Irel.' p. 16 ; H. G. Bronn, 

 1848, 'Index Palgeont.' p. 747. 



Fleurotoma articulata, T. Brown, 1849, 'Illustr. Foss. Conch. Gr. Brit. & Irel.' 

 p. 253 & pi. xxxvii* fig. 20. 



Murchisonia articulata, A. d'Orbigny, 1850, ' Prodr. Paleont. strat.' vol. i, p. 31 ; 

 J. Morris, 1854, Cat. Brit. Foss. p. 258 ; J. Sowerby, 1867, ' Siluria,' 4tli ed. pi. xxiv, 

 fig. 2 ; J. J. Bigsby, 1868, ' Thes. Sil.' p. 157. 



Horm.otoma articulata, J. W. Salter, 1873, Cat. Cambr. & Silur. Foss. p. 172. 



Murchisonia articulata, J. D. La Toucbe, 1884, ' Geol. of Shropshire,' p^ 80 & 

 pi. xviii, fig. 635 ; F. Roemer, 1885, Pal. Abhandl. vol. ii, pt. v, p. 125 & pi. ix, 

 fig. 18 ; R. Etheridge, 1888, ' Foss. Brit. Is.' vol. i (Pala30zoic) p. 113. 



Description. — Shell very elongated, turreted, composed of more 

 than ten whorls. Whorls increasing gradually, high, convex, 

 smooth. Sutures deep, moderately inclined. Sinual band situated 

 near the middle of the whorl, level with the surface or but slightly 

 depressed, defined either by a very fine thread on each side, or 

 merely by the lines of growth. Lines of growth retreating very 

 obliquely backward above the band, and forward below, strongly 

 arched on the band itself, indicating a deep sinus in the outer lip. 

 Aperture subovoid. Columella rather inclined, arched forward, 

 slightly thickened. Base produced. UmbiJicus closed. 



