230 CRETACEOUS GASTROPODA 
7. MScala*, Klein, 1753 [Scalaria, Lamck., 1801,] (H. and A. Adams’ Gen. I, 
p. 220); varices numerous, strong, equal; apertural margins thickened, continuous. 
The sub-genera, Clathrus, Oken, and Opalia, H. and A. Adams, may serve as sub- 
divisions of Scala, but it would be scarcely possible to give them generic value, 
unless the separation is carried out into much greater detail. 
8. LHglisia, Gray, 1840 (H. and A. Adams’ Gen. I, p. 354); whorls spirally 
striated with some sub-obsolete, transverse varices ; aperture roundish, internally with 
thickened lips. We believe with Deshayes and others, that the species known under 
this generic name are more related to Scala, than to Turritella, and we therefore 
place them here. The species, however, quoted by Deshayes under Scalaria (Anm. s. 
vert. Foss. de Paris, 2me. edit., Vol. II, p. 353), in his sub-division Eglisia, both 
probably belong to Mathilda, Semper, while those described under Pyrgiscus 
are true Hglisie. As regards the general form of the shell, most of the species 
of Zglisia exhibit very remarkable relations to Stephopoma, Moerch, of the 
Veruerip#, to which they form a connecting link. 
9. Chilocyclus, Bronn, 1850 (Letheea, Vol. II, p. 75, Cochlearia, Brown, 1841, 
apud Miinster; non idem, Klein, 1753, and others). Shell moderately thick, with 
obsolete or small tubercle-like varices, aperture circular with the margins united, 
internally thickened and expanded. The name Cochlearia has not only been used in 
Botany, but some time ago by Klein also in Conchology, and was therefore rejected 
by Bronn for the designation of a new genus, which had to be renamed. The genus 
includes only two triassic species, Ch. carinatus, Bronn, and Ch. Bronni, Klipst. 
Pterostoma, Desh. (Paris Foss., 2nd edit., Vol. IT, p. 428,) of the Rrssorpm is a 
related form, but it has the anterior portion of the aperture more produced, 
while the internal space of the same is not circular, and thus it approaches more 
nearly to other true Rrssorpz (vide postea). 
10. Scoliostoma, Bronn, 1838 (vide Sandberger’s Rhein. Schichtensystem, 
p- 222,) is chiefly known from palzeozoic species. The shell is like Chilocyclus 
with the united margins of the aperture largely expanded, but the last whorl is 
irregularly produced and the aperture reflected upwards or laterally. Should the 
irregularity of the last volution be proved to have no generic value, both this 
and the last named genus will have to be united under the name of Scoliostoma. 
11. Constantia, A. Adams, 1860 (Ann. Mag. Nat. Hist. V, p. 300,) a form 
somewhat resembling Lglisia, with decussate transverse and spiral ribbings. The 
genus is founded upon a recent shell from the seas of Japan. 
12. Compsopleura; we are acquainted with this generic name merely from 
Conrad’s Check list of eocene fossils, p. 15; Smith. Miscell. Coll. No. 200, 1866. 
The species quoted is C. trvinodosa, Con., from the so called lower eocene beds, which 
have been shown by Gabb and others to be partially cretaceous. 
13. Scalina, ibid, p. 29, with the species Se. triquintinaria, Con., from the 
upper eocene beds of Vicksburg. 
* Vide Ostrac., p. 52, pl. 3, fig. 66. There could never have been a mistake as to the real signification of 
the name Scala of Klein. 
