TROCHUS. 373 
umbilicus, likewise, is of considerable importance, being deep, though not funnel- 
shaped ; itis encircled by tuberculations of considerable size. 
Relations and Distribution of Trochus Winwoodi.—Mr. Tawney described his 
species as having the umbilicus closed, but in point of fact this is hardly ever the 
case with the specimens from Dorset. Small forms are not very far from the 
conical variety of Zrochus sybilla, but the ornaments are always finer, and the shape 
of the body-whor] different. There are other varieties—almost distinct species. 
Abundant in the Concavus-bed at Bradford Abbas. Occurs also at Stoford and 
Halfway House, on or about the same horizon. There isa short conical variety at 
Beaminster, to which a varietal name might be given. 
310. Trocuus pupticatus, Sowerby, 1817. Plate XXXI, fig. 10. 
1817. Trocuus puprticatus, Sowerby. Min. Conch., pl. clxxxi, figs. 5, 5. 
1852. a _ -- d’Orbigny, Terr. Jur., vol. ii, p. 275, 
pl. ecexiii, figs. 5—8. 
1867. _ — — ?var. Laube, Gast. B. J. von Balin, p. 10, 
pl. ii, fig. 7. 
cf. also —_ — — Tawney, Dundry Gasteropoda, p. 32 (24). 
Non. Tvrso pupiicarus, Sow. CGoldfuss, Petref. Germ., pl. elxxix, fig. 2. 
Non. Trocuvus pupticatus, Quendstedt. Der. Jura., p. 314, pl. xliii, figs. 18, 19. 
Bibliography, §c—The types of Trochus duplicatus, T. angulatus (concavus), and 
T. dimidiatus came from Little Sodbury; these are now in the Sowerby type- 
collection at the British Museum. The village of Little Sodbury is at the foot of 
the Cotteswold escarpment and on the Lias; but, as far as I have been able to 
ascertain, the parish pit in the early part of the century must have been well up the 
hilland towards the top of the Inferior Oclite. The horizon is doubtless represented 
in the adjacent quarry on Horton Hill, where the equivalent of the Upper Trigonia- 
grit of the Cotteswolds (Parkinsoni-zone), yields a number of interesting Gastero- 
poda. Vide supra, pp. 57, 58. 
Mr. Tawney was, I consider, too comprehensive in his synonymy ; for instance, 
Quenstedt (loc cit.) expressly says that the species figured by Goldfuss is not that 
of Sowerby. 
Description : 
Height ; - ; . 15 mm. 
Width : ‘ : A . 155 mm. 
Spiral angle . : : : . 62°—66°. 
Shell regularly conical, moderately umbilicated ; spire elevated, considerably 
48 
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