﻿FROM THE LOWER CHALK. 



219 



Echinoconus subrotundus, Mantell, 1822. PI. LII, fig. 1 a— -f; PI. LIII, fig. 2 a— /, 



fig. 3. 



Conulus subrotundus, Mantell. Geol. of Sussex, p. 191, tab. xvii, figs. 15 — 18, 



1822. 



Galerites subrotunda, Jgassiz. Monogr. des Radiaires, Mem. Soc. des Sc. Nat. de 



Neuchatel, t. i, p. 186, 1836. 



— — Desmoulins. Etudes sur les Echinides, p. 256, 1837. 



— — Bujardm. In Lamarck's Auimaux sans Vertebres, 2e ed., 



t. iii, p. 313, 1840. 



— — Besor. Monogr. des Galerites, p. 18, tab. ii, figs. 11 — 14, 



1842. 



— — Morris. Catalogue of British Fossils, p. 53, 1843. 



— — Agassiz and Besor. Catal. rais. des Echinides, Ann. Sc. 



Nat., 3e eerie, t. vii, p. 148, 1847. 



— Leskei, Besor. Id., p. 148, 1847. 



— subtruncata, d'Orbigny. Prod, de Pal., t. ii, p. 272, 1850. 



— subrotundus, Forbes. In Dixon's Geol. of Sussex, p. 340, 1850. 



— — Forbes. Mem. of Geol. Survey, decade iii, p. 6, 1850. 



— — Morris. Catal. of Brit. Foss., 2nd ed., p. 80, 1854. 



• Echinoconus — d'Orbigny. Rev. et Mag. Zoologie, t. vi, p. 20, 1854. 



— — Cotteau. Paleontol. Francaise terrains Cretaces, t. vi, 



p. 517, pi. 997, figs. 8— 12, 1856. 

 Galerites — Besor. Synopsis des Echinides Foss., p. 183, 1856. 



Echinoconus — Cotteau. Echinides de la Sarthe, p. 283, pi. xlvii, fig. 4, 



1860. 



Diagnosis. — Test subcircular, rounded anteriorly, a little contracted, and subangular 

 posteriorly ; upper surface elevated, sub-conoidal and convex ; base flat, rounded at the 

 border, sides a little inflated ; mouth-opening small, roundish central ; vent large, 

 marginal, elliptical ; ambulacra narrow, plates of both areas covered with small flat, 

 equal-sized tubercles. 



Description. — Under the name Galerites vulgaris, Leske, it is probable that moulds of 

 E. subrotundus have been included. Klein's tab. xiii, fig. c — k, and tab. xiv, fig. a — k, 

 are cited by Lamarck as types of G. vulgaris. As these figures all represent siliceous 

 moulds, a doubt may be allowed to rest on their identity with the form I have figured in 

 Plates LII and LIII. Dr. Mantell also gave the name Conulus subrotundus to a doubtful 

 cast ; but Desor has published excellent figures of this species from an English specimen 

 collected in the Isle of Wight, and contained in the Museum at Neufchatel. Professor 



