48 MISS J. BONALD ON THE GENUS ACLISINA. [Feb. 1 898, 



shells in order to compare them with fossil ones. Mr. Mcflenry, 

 of the Irish Geological Survey, has been very good in giving me 

 information about the Irish horizons. Mr. G. F. Harris has kindly 

 given me some valuable hints with regard to the study of the proto- 

 conchs. I must also thank Mr. Goodchild for revising these notes. 



Family Turritellidse. 

 Genus Aclisina, De Kon. emend. 



Aclisina, L. G. De Koninck, 1881, ' Faune Calc. Carb. Belg.' Ann. Mus. Roy.- 

 Hist. Nat. Belg. vol. vi, t. iii, pp. 86. 



Terebra or Turbo ? (pars), D. Ure, 1793, ' History of Rutherglen & E. Kilbride,' 

 p. 308 & pi. xiv, fig. 11. 



Turritella ? (pars), J . Fleming, 1828, ' Brit. Animals,' p. 305 ; ? (pars), J. Phillips^ 

 1836, ' Geol. Yorks.' vol. ii, p. 229 & pi. xvi, figs. 23 & 26 ; ? (pars), E. d'Eicbwald, 

 1860, 'Lethasa Rossica,' pp. 1120, 1121 & pi. xlii, figs. 4 & 5; ? F. B. Meek & A. H, 

 Wortben, 1866, ' Pal. Illinois,' vol. ii, p. 382 & pi. xxix, fig. 8. 



Loxonema (pars), F. M'Coj'', 1844 {non J. Pbillips), ' Svn. Char. Carb. Limest. 

 Foss. Irel.' p. 30, pi. iii, fig. 1 & pi. v, fig. 6; ? J. W. Dawson, 1868, 'Acad. GeoL' 

 2nd ed. fig. 122 & pp. 309, 310 ; ? A. H. Wortben, 1890, Geol. Surv. Hlinois, Pal. 

 vol. viii, p. 140 & pi. xxiii, figs. 9 & 9 a. 



Aclis, R. P. Stevens, 1858 {non Sv. Loven), Am. Journ. Sci. ser. 2, vol. xxv, p. 259 ; 

 F. B. Meek & A. H. Wortben, 1873, ' Pal. Illinois,' vol. v,p. 596 & pi. xxix, figs. &a&b; 

 ? C. A. Wbite, 1882, ' Rep. on the Carb. Invert. Foss. New Mexico,' U.S. Geogi-apb. 

 Sui-v. W. of lOOtb Merid., Appendix, p. 35 & pi. iii, fig. 9 



? Murchisonia (pars), G. C. Swallow, 1858, Trans. St. Lonis Acad. Sci. vol. i, 

 p. 203. 



MurcJiisonia (pars), J. Armstrong, J. Young, & D.Robertson, 1876, 'Cat. W.Scot. 

 Foss.' p. 56. 



? TurboniUa, H. B. Geiuitz, 1866 (non A. Risso), ' Carbonfoimation u. Dyas in 

 Nebraska,' p. 5 & pi. i. fig. 19. 



Aclisina, J. Donald, 1885, Trans. Cumberl. & Westmorl. Assoc, no. ix, p. 131 & pi. ii, 

 figs. 2-5 ; D. P. ffiblert, 1887, ' Descr. de qq. Especes Devon, de la Mayenne,' Bull. Soc. 

 d'Etudes Scient. d' Angers, p. 10 & pi. viii, fig. 4 ; S. A. Miller, 1889, 'N. Am. Geol. & 

 Palajont.' p. 395, & 1891, ' Geol. Surv. Indiana,' Pal., I7tb Ann. Rept. p. 695 & pi. xiv, 

 fig. 10 ; G. F. Wbidborne, 1896, ' Monogr. Dev. Fauna S. of England,' Palseont. Soc. 

 vol. iii, pt. i, p. 52 & pi. v, fig. 10. 



Description. — Shell small, elongated, conical, composed of nume- 

 rous whorls. Apex blunt. Protoconch formed of about one smooth 

 whorl, which is sometimes more or less detached from the highest 

 whorl of the spire on the umbilical region. A faint rib indicates its 

 junction with the conch, upon which the ornamentation begins 

 almost immediately. "Whorls convex, spirally striated. Sutures 

 deep. Outer lip as indicated by the lines of growth sigmoidal, 

 retreating from the suture and forming a wide shallow sinus, then 

 arching prominently forward and retreating again below on the 

 base of the shell. Aperture ovoid. Columella nearly straight, 

 slightly thickened. Inner lip reflected on the body-whorl. Base 

 convex. Umbilicus closed. 



Dimensions. — The length varies from 2 or 3 mm. up to about 

 15 mm. 



Rema^'Tcs. — The protoconch of Aclisina is a very distinctive fea- 

 ture. It is frequently somewhat irregular, but not sinistral. The 

 initial part in many cases appears to be central, and the whorl coils 



