22 SUPPLEMENT TO GREAT OOLITE MOLLUSCA. 
Monoponta Exicua, Zyc. Tab, XLIV, fig. 29. 
Testa parva ovata, spira elata, obtusa, anfractibus tribus, subplanis, anfractu ultimo 
rotundo ; striis tenuibus cingendis, costisque obliquis depressis, crebris, decussatis ; apertura 
ovata, columella ad basin incrassato, subumbilicato. 
Shell small, ovate ; spire elevated, obtuse; volutions three, very slightly convex, the 
sutures distinctly marked; the last volution rounded with densely arranged, delicate, 
encircling striations, which are decussated upon the upper and middle portions of the 
volution by numerous depressed, oblique cost, which are rendered somewhat granular by 
the striations ; the aperture is ovate, the columella is thickened at its base, and there is a 
slight umbilical depression ; the base of the last volution is destitute of costz. 
Geological Position and Locality. he Great Oolite of Minchinhampton Common, 
collected by Mr. Witchell. 
Monoponta Lycerri, Whiteaves, MSS. ‘Tab. XXXI, figs. 14, 14a. 
Testa subdepressa, spira brevi, exserta; anfractu ultimo permagno lateribus planatis, 
costisque magnis, crenulatis, cingendis, basi constricta sulco magno. 
Shell depressed; spire short and slightly mammillated, the last volution very large, 
angulated at its upper margin, flattened upon its sides, and slightly convex towards the 
base, which has a large, encircling furrow; the aperture is moderately large, wide above, 
contracted towards the base ; the columella is rounded and very tumid. 
The whole shell is encircled with rows of rope-like crenulated cost, the upper border 
and flattened sides being formed by three costz larger than the others; beneath these are 
five cost diminishing symmetrically to the basal furrrow ; the upper surface, which is 
flattened, has three encircling coste, within which rises a small, mammillated apex. 
Lateral diameter one fourth greater than the height. 
The large, rounded costz, flattened sides, and depressed figure, readily distinguish 
it from allied species. 
Geological Position and Locality. In soft, pale, gray, marly limestone (Bradford 
Clay ?), Islip, Oxon., collected by J. F. Whiteaves, Esq. 
Monoponta sparsistTRiata, Lyc. ‘Tab. XLV, fig. 9. 
Testa parva turbinata, depressa, spira anfractibus 4 ; covexiusculis, strus 6, cingendis ; 
apertura ovata, bast subplané, lavigato, umbilico nullo. 
Shell small, turbinated, depressed ; spire moderately elevated, consisting of four rather 
