Nigerian Eocene Mollusca. 37 



Family BUCCINID^. 



Buooinorbis kitsoni, sp. nov. 



PLATE 3, figs. 16-19. 



DESCRIPTION. Shell robust, sub-globose, spirally furrowed and funiculate 

 at the base ; spire elevated, conical, acuminate with about 7 depresso-convex 

 whorls divided by a canahculated suture, protoconch smooth, composed of 

 2^ whorls, apex obtuse ; body-whorl rounded, rather higher than wide, about 

 twice the height of the spire, in age provided with a broad sutural platform, 

 semi-ovafely notched at the base ; labrum nearly vertical, sharply margined, 

 posteriorly sinuate, and with a thickened callosity, smooth within, basal margin 

 with a dentiform projection at the furrow and an angulation at the notch ; 

 aperture narrowly oval, bicanaliculated, widely notched in front ; columella 

 smooth, excavated in the centre, slender and twisting outwardly at the base, 

 callosity extensive, thickest posteriorly where it forms a narrow canal in con- 

 junction with the raised callosity on the labrum, the umbilical region auriculate, 

 excavated, and terminally pointed ; surface possessing nearly vertical growth, 

 lines sinuated at the suture and crossed by more or less obscure spiral striations, 

 basal striations strongest on young specimens. 



DIMENSIONS. 



Adult. Young. 



Alt 47 ... 17 millimetres. 



Lat 32 ... 9 



REMARKS. This shell differs from the true Pseiidoliva ( = crassa, Gmelin 

 =plumbea of Chemnitz) of the Atlantic in its more produced spire, in the 

 development of a prominent sutural platform especially in the adult stage, as 

 also in the presence of the elongately auricular, umbilical cavity, such characters 

 mostly belonging to the allied genus, Bwcrinorbis of Conrad 1 founded on 

 Monoceros Pyruloides and M. fusiformis both of Lea, 2 which are equivalent 

 to Conrad's Monoceros vetustus, from the Claibornian Eocene beds of 

 Alabama. The present species is, however, less inflated at the periphery, 

 not pyruliform, more angulate at the suture, and possessing a shallower 



1 American Journ. Conch., 1865, Vol. i, p. 21, and Fossil Shells of the Tertiary Formations of 

 North America, 1835, Vol. i, No. 3, p. 37, pi. 15, fig. 3. 



2 Contributions to Geology, 1833, pp. 161, 162, pi. 5, figs. 166, 167. 



