1870.] TATE— GLOUCESTERSHIRE LIAS. 407 
pressed; anterior side rounded, posterior but little attenuated; or- 
namented by concentric acute folds and striae. 
Dimensions. Length 0:4 inch; height 0:12 inch; diameter 0-1 
inch ; length of anterior side 0-22 inch. 
This species belongs to the group Cercomya, Agassiz, but differs 
from the two other Liassie species (A. precursor, Quenstedt, and A. 
Delia, D’Orb, or A. sinemuriensis, Martin) by its form and plications. 
Locality. Anmonites-Jamesont zone, Aston Magna (Slatter). 
InocERAMUS INCURVATUS, nov. sp. (PI. XXXVI, figs. 2 & 2a.) 
Shell subrhomboidal; hinge-line nearly straight; umbones sub- 
marginal, inflated and incurved; outer surface marked with con- 
centric folds, 
The figure of the fossil is not perfect, but the distinctive charac- 
ters are the gibbosity of the umbonal region and the strongly 
ineurved beaks. 
Length of longitudinal axis 23 inches. 
Locality. Zone of Ammonites capricornus, Cheltenham (2. T.). 
Arca StrIcKLANDI, Tate. 
Arca truncata, Buckman, Geol. Cheltenham, t. 5. f. 6, p. 26 (1845), 
non Arca truncata, G. B. Sowerby (1833), non Arca truncata, 
Reuss (1843). 
Specific name to commemorate the paleontological labours of 
Mr. Hugh Strickland in the Lias of Gloucestershire. 
Distribution. Zone of Ammonites Jamesoni, Cheltenham! Aston 
Magna (Slatter). Yellow Lias, Cheltenham (Buckman). 
Lepa GRAPHICA, nov. sp. (Pl. XXVI. fig. 12.) 
Shell elliptical, rounded and inflated in front, posteriorly rostrated, 
ornamented with fine and closely set concentric strive, which form 
chevrons on the postmedial line. 
Dimensions. Breadth 1 inch; length of anterior side 0:35 inch: 
height 0:35 inch ; diameter 0:3 inch. 
This species has the general form of Z. rostralis, Lamk., and a few 
other Liassic species, but is distinguished from all, especially by its 
chevron-like ornamentation. 
Locality. Zone of Ammonites capricornus, Mickleton Tunnel 
(Gavey). (Coll. Geol. Soc. and Geol. Surv. Mus.) 
Nvucuta UNGULELLA, nov. sp. (Pl. XXVI. fig. 11.) 
Nucula variabilis, Quenstedt, Der Jura, t. xxiii. f. 28, p. 188 
(1858), non Sow.; id. Dumorticr, Dépots Jurassiques, ii. 
p- 121, 1869. 
Shell ovate, subtrigonal,; umbones inflated, depressed, recurved, 
submareginal ; a keel proceeds from the umbo to the antero-ventral 
margin, enclosing a subconcave area; anterior margin truncated, 
posterior elongated and slightly compressed ; ventral margin curved; 
lunule deeply impressed; surface covered by distant strong lines of 
growth ; hinge-line with ten serial anterior teeth and fifteen posterior, 
