190 EOCENE MOLLUSCA. 



No. 124. Conus diadema, F. E. Edwards. Tab. XXIV, fig. 8 a — d. 



Conus diversiformis, Sow. (non Desk.) 1841. Min. Con., vol. vii, p. 26, t. 623, figs. 



3, 4, 6. 

 — — Morris. 1843. Cat. Brit. Foss., p. 143. 



Sow. 1850. Dixon's Geol., &c, of Suss., p. 108, t. 8, fig. 10. 

 — Morris. 1854. Cat. Brit. Foss., 2d edit., p. 244. 



C. testa conicd, oblongd, sub-turritd, coronatd, leevi, ad basin transversim obscure 

 sulcata ; spird elevatd, sed trientem totius testa longitudine nequaquam cequanti ; anfracti- 

 bus numerosis, angulatis, marginibus posticis depressis, sub-cavatis, concentrice lineatis : 

 aperturd angustd ; labro mediocriter arcuato, postice late emarginato. 



Var. pyriformis (fig*. 8 d). Testa spird depressd. 



Conus pyriformis, Sow. 1850. Dixon's Geol., &c, of Suss., pp. 108 and 189, t. 8, 



fig. 18. 

 Morris. 1854. Cat. Brit. Foss., 2d edit., p. 244. 



A smooth, oblong, conical shell, with a turreted spire, formed of numerous 

 (10 — 12) volutions, and moderately elevated, varying to some extent in different 

 individuals, but never attaining a height equal to a third part of the length of the 

 shell. The whorls are nearly straight on the sides, with the posterior margins much 

 depressed, somewhat concave, and ornamented with four or five thickish, concentric, 

 raised lines, separated by shallow, rounded furrows ; the angles of the whorls present 

 a series of oblong, regular tubercles, which are continued almost to the last whorl, 

 when they are replaced by a rounded, cord-like thickening of the shoulder ; the front 

 part of the whorls is traversed by shallow, irregular furrows, which are effaced 

 towards the middle part of the shell. The aperture is narrow, with parallel margins ; 

 the outer lip moderately arched, and presenting a wide, shallow curvature between 

 the angle and the suture. 



The specimens separated by Mr. Sowerby, under the specific name pyriformis, have 

 a much depressed spire associated with the tuberculation, and other characters which 

 distinguish the present species, of which, therefore, I regard them as a variety only. 



The shells for which I propose the specific name, C. diadema, were referred by Mr. 

 Sowerby, in part to C. deperditus (Brug.), and in part to C. diversi/ormis (Desh.). In the 

 former species, however, the shell is narrower and more turbinate, with a more curved 

 outer lip, and the tuberculation on the spire, where it occurs, is feeble and lost on the 

 very early whorls; and in the latter species, M. Deshayes, in his description, states 

 expressly that the angles of the whorls are somewhat sharp, and always simple ;* 



* It is somewhat difficult to appreciate the distinct specific value of the shells constituting the species 

 C. diversi/ormis, without an examination of a series of specimens equal to that upon the study of which 

 M. Deshayes proposed the separation. To the unschooled eye they appear to be only broader forms of 

 C. deperditus, with more variable spires. 



