QUEENSLAND INOCERAMI—WHITEHOUSE. hoe 
Obs.—This species is distinguished by its erect habit. 
The hinge line is longer than in either of the two species 
deseribed above. The area within the pallial line is about 
the same as in /. maximus, but the direction of the axis of 
growth and only slight axial curvature ally it rather to 
IT. scutulatus. Probably both this species and J. maximus 
represent off-shoots from /. scutulatus. 
COMPARISON WITH OTHER SPECcIES.—/. scutulatus may 
be closely compared with the short form of /. crippsi var. 
reachensis Eth.° from the Cenemanian of England. Both 
species have the subequal anterior and posterior expansions 
of the valves, and there is a certain scutulate outline, but 
much less pronounced, in the latter variety. It differs from 
the English form in having the umbones more prominent, 
the hinge line shorter, and the concentric ornamentation 
much less pronounced. 
I. marimus shows a pronounced resemblance to the 
widespread J. lapiatus' (Schloth.) (Cenomanian and L. 
Turonian), which is also a large form. The resemblance is 
most apparent in the direction of growth oblique to the 
hinge line (a characteristic feature of J. labiatus). It 
differs from this form particularly in the more-acute 
umbones and the less-prominent ornamentation. 
Hichwald* figures a specimen labelled J. mytiloides- 
from the Cretaceous of Russia, which very closely resembles 
the original of pl. V., fig. 2, of this paper. (J. mytiloides, 
it is to be noted, is regarded by Woods as a synonym of J. 
labiatus.) Again, the Queensland form differs in tiie more- 
pronounced umbones and less-prominent ornamer:tation. 
Woods has shown’ for the English forms that /. 
labiatus has most probably evolved direct from J. crippsi 
var. reachensis, and it is thus interesting to note that J. 
scutulatus and I. maximus, which are themselves connected 
by intermediate forms, are individually comparable with 
° See H. Woods: ‘‘ Monogr. Cret. Lamellibr.’’ (Paleont. Soc.), 
VOL JUS IM jE eis, EDU NAUU ES ake. De gal, OUI aie 
"See Wocds, op. cit., pp. 281-284, pl. L. 
§ Hichwald, ‘‘Lethea Rossica’’ (per. moyenne), pl. XXLI., fig. 6. 
“Woods, ‘‘ The evolution of Inoceramus in the Cretaceous period,’” 
Q.S.G.S. LXVILL., 1912, p. 13. 
