GASTEROPODA, 61 
Specimens, as small as the head of a pin, are scattered over the blocks of white stone 
at Bussage, and planking at Minchinhampton Common—these are smooth. The larger 
shells are more distinctly sulcated, and occasionally attain a diameter of three eighths of 
an inch. 
Locality. It occurs in all the shelly beds at Minchinhampton; at Ancliff, in Wiltshire ; 
and at Charter House, Hinton, Somersetshire. Langrune, France. 
Family—TuRBINID&. 
Trocuus, ZLinneus, 1758. 
Shell turbinated, conical; spire elevated, consisting of numerous whorls; under surface 
discoidal ; aperture more or less depressed obliquely, entire, generally angular; columella 
curved, more or less prominent at its union with the outer lip, contiguous to the axis of 
the shell. 
The fossil species of the Great Oolite are all very small, and are tolerably numerous in 
the shelly beds. 
Trocuus Dunxeri. Plate X, figs. 3, 3a. 
T. Testa conicd, glabra; anfractibus levigatis et planis (4—6); apice acuto; apertura 
obliqua, umbilico nullo. 
Shell conical, smooth; whorls very smooth and flattened ; apex acute; aperture oblique; 
no umbilicus. 
The extreme flatness of the whorls, and moderate elevation of the spire, are the chief 
features; the good specimens have oblique lines of growth upon the last whorl, near to 
the aperture. 
Locality. This little species is tolerably abundant in the white stone of Eastcombs 
and Bussage. 
Named after Dr. W. Dunker, Professor at the Polytechnic School of Cassel. 
This species has some affinity with the Zrochus glaber, Koch (Goldf. Pet. t. 1796.12); 
but the volutions are striated and the base more convex. 
Trocuus pLicatus, Archiac. Plate X, figs. 8, 8a. 
Trocuus PLicatus, Archiac. 1843. Mem. Soc. Geol France, vol. v, p. 379, t. 29, fig. 5. 
— _ D Orb. 1850. Prod. Paléont., p. 300. 
— _ Bronn. 1848. Index Paleont., p. 1304. 
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