ACLISINA. 51 



The Carboniferous G. rectus, de Ryckholt/ approaches so close as to show no 

 points of difference in the original figure ; but, as given by de Koninck/ who unites 

 with it G. corpuratus, de Ryckholt,^ it is distinguished by having a sharper, more 

 regular and curved apex, and a convex back. De Koninck^ also doubtfully joins 

 to it G. subpUcatum, Meek and Worthen, which seems indistinguishable from low 

 forms of the present shell. 



IV. Family — Soalariid.e, Broderip, 1839. 

 1. Genus — Hglopell.v, M^Coy, 1852. 



1. HoLOPBLLA TENUisuLCATA, Sandhergev. Plate V, fig. 7 ; and Plate VI, figs. 3, 3 a. 



1891. HoLOPELLA TENUISULCATA, WMdlome. Dev. Fauua, vol. i, p. 255, 



pi. xvii, fig. 20 ; aad pi. xviii, fig. 10. 



Size. — Length 24 mm., width 10 mm. 



Localities. — Three specimens from Kingdon's, Shirwell, are in the Barnstaple 

 Athenaeum. 



JSemar/uS.— These fossils, though almost entirely in the form of casts, seem 

 undoubtedly to correspond with the South Devon shell. A small portion of the 

 surface remaining on one of them shows the oblique transverse striae characteristic 

 of the species. 



2. Genus — Aclisina, de Eoninch, 1881. 



This genus was formed by de Koninck for elongate shells with convex 

 spirally striated walls ; oval mouth ; smooth, entire, and unexpanding outer lip ; 

 slightly thickened and unbent columella; and imperforate axis. 



He distinguishes it from Murchisonia by the absence of a sinus-band ; from 

 Loxonema by its spiral strise ; from Tnrritella by its more convex whorls and 

 deeper suture ; and from Aclis by its simple columella. 



1 1867, de Eyckholt, 'Melange Pal.,' pt. 1, p. 36, pi. i, figs. 5, 6. 



2 1883, de Koninck, ' Ann. Mus. Roy. H. S. Belg.,' vol. viii, pt. 4, p. 171, pi. xlvi, figs. 14—16, 

 23, 24. 



^ 1867, de Eyckholt, ' Melange Pal.,' pt. i, p. 38, pi. i, figs. 11, 12. 



