Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/569

1870.] TATE — GLOUCESTERSHIRE LIAS. 403 It occurs in the zones of Am. raricostatus, Cheltenham; Am. Jamesoni, Aston (Slatter) ; and Am. margaritatus, Dumbleton ! ; and on the Continent it is quoted from, the zone of Am. Bucklandi, Fleigneux.

B. — From the lower zones of the Middle Lias.

Turbo admirandus, nov. sp. (Pl. XXVI. fig. 10.)

Shell small, heliciform, a little broader than high; spire short, with an obtuse apex composed of four inflated whorls, the superior of which are angulated and ornamented above by curved plications, which extend a little over the keel, and are crossed by longitudinal costellae, the remaining portion cancellated and nodulose ; the last whorl slightly inflated and subangular ; base radiately costulate ; peristome entire, thickened, and channelled anteriorly; aperture circular ; umbilicus of moderate size and round.

Dimensions. Length 0.23 inch ; diameter 0.22 inch ; height of last whorl 0.17 inch.

Localities. Zone of Ammonites Jamesoni : Cheltenham (Tate, Buckman) ; Aston Magna (Slatter) ; ? Campden (Brodie).

Trochus Thetis, Munster, Goldfuss, t. 179. f. 10*. (Pl. XXVI. fig. 4.)

Turbo heliciformis, Quenstedt, Jura, t. 19. f. 25*.

Shell small, conical, spire elevated ; apex acute, composed of 4—5 flat whorls, separated by a channelled suture; last whorl biangulated; upper surface ornamented with about twenty-four thick nearly straight costae, which terminate in a subspinous tubercle on the elevated upper carina. In some examples the transverse ribs are terminated superiorly and inferiorly by tubercles. Prom the tuberculated rim of the upper keel proceed fine closely set curved striae, which are continued on to the base of the shell. Base nearly flat, with four concentric ribs ; columella oblique, with a callous expansion over the umbilical fissure ; aperture oblique.

Dimensions. Length and breadth 0.20 inch.

Affinity. T. Thetis is closely related by its ornamentation and figure to T. Doris, Munster, Goldfuss, t. 179. f. 9, from the Lias of Pretzfeld, placed by D'Orbigny in the Toarcien, but cited by Dumortier from the zone of Ammonites angulatus in the South of France ; it differs from that species in its biangulated last whorl and in having two rows of tubercles and not three; other minute differences arc observable.

Distribution. Zone of Ammonites Jamesoni : Cheltenham (Tate, Buckman); Aston Magna (Slatter). Zone of Am. margaritatus, Hechinger (Quenstedt) ; Amberg (Goldfuss); St. Bonnet, Rhone (Dumortier).

Exelissa. numismalis, Tate, Annals and Mag. Nat. Hist. Dec. 1869. (Pl. XXVI. fig. 5.)


 * Figures represent casts only.