131 



Edn., p. 285. I am indebted to the kindness of Mr. Young for 

 specimens of this species. 



Length of a shell having six whorls, and of which the apex is 

 broken, 3I mm., width of body whorl, i| mm. 



Locality — Capelrig, East Kilbride. 



Horizon — Shales of the Lower Limestone Series, t 



Genus Aclisina (De Koninck). 



Shell small, elongated, of numerous convex whorls, which are 

 ornamented with spiral keels. Mouth, oval ; outer lip thin, 

 entire, and not produced; columella, slightly thickened. No 

 umbilicus. The shells of this genus are generally slender, and 

 do not attain a great size. 



In 1866, Dr. Geinitz {Carbonformation und Dyas m Nebraska, 

 p. 5, Tab. i., f 19,) desribes a shell as Turbonilla swallowiana, 

 which probably belongs to this genus. And in the same year 

 Messrs. Meek and Worthen {Pal. Illinois, vol. ii. p. 382, pi. xxvii. 

 f. 8 and %a^ describe and figure Turritella ? stevensana, which 

 may also be referred to this genus. In both these shells, however, 

 the lines of growth appear to be more strongly sigmoidal than in 

 any of the species of Aclisina I have yet seen. Other shells which 

 may possibly be referable to Aclisina, are — Loxonema polygyra, 

 M'Coy; L. sulcatula, M'Coy {Syn. of the Chars, of the Carb. Lst. 

 Foss. of Ireland, 1844) ; Z. acutula, Dawson {Geol. Acadia, p. 309, 

 f. 122, 1868); Murchisonia minima. Swallow {Trans. St. Louis 

 Acad., p. 203, 1856-60,) &c., and some few others whose characters 

 I have not yet been able to examine carefully. 



Aclisina striatula. (De Kon.) PI. II., figs. 2, 2a. 



Aclisina striatula, L. G. De Koninck, 1881. An?iales du Musee 



Royal IfHistoire Naturelle de Belgique, T. vi., 3me Partie, p. 86, 



PI. ix., fig. 57, 58. T. viii., 4me Partie, PI. xxxiii., fig. 41, 42. 



+ The Calciferous Sandstone Series of Scotland represents the Lower Lime- 

 stone Shale and the lower part of the Mountain Limestone of England. The 

 higher members of the Lower Carboniferous Rocks, which are known to 

 Scottish geologists as the Lower Limestone Series, Lower Coals and Ironstones, 

 and the Upper Limestone Series, are now known to lepresent the upper part of 

 the Mountain Limestone and the Yoredale Rocks of the English geologists. 



