File:The Quarterly journal of the Geological Society of London (12711774514).jpg

WOODWARD HIPPURITIDiE.
45
been approved of by M. Desbayes, to wbom I submitted tbe speci-
mens during his last visit to England.
Figs. 8 & 9. — Longitudinal sections o/* Hippurites and Radiolites :
reduced ^.
Fig. 8. Fig. 9.
Fig. 8. Hippurites cornu-vaccinum. Fig. 9. Radiolites cylindraceus.
The sections are taken through the teeth .t, f) and muscular apophyses (a, a') :
d, outer shell-layer ; r, inner shell-layer ; /, dental plate df lower valve ; u, um-
bonal cavity of upper valve ; i, intestinal channel.
Hitherto it had been supposed, either that the two divisions of the
anterior muscular impression represented both the adductors, or
that the posterior adductor occupied the channel between the second
and third inflections, — where there is not the slightest indication
of it.
Almost the last specimen I have obtained is a genuine upper valve,
brought by Mr. W. K. Loftus from the Turco-Persian Frontier *
(PI. III. fig. 4). This fossil had been broken by an accidental fall,
but enough remained, when the specimen was mended, to show many
interesting particulars. Two small portions of the lower valve .s,s)
— viz. the summits of the second and third inflections — remain ad-
hering to the lid, surrounded by the channel before noticed, which
seems intended to lodge some winding canal, or to allow the passage
of a current. This example also shows the base of the posterior
tooth (t), the deep conical cartilage-pit, and the curved umbonal
cavity. The stony mould of this cavity was detached by the fall,
and showed that originally it was covered up halfway by the base
of the anterior tooth. The margin is perforated by a single line of
circular foramina, the orifices of those radiating canals which are seen
in the weathered outer surface.

• See Quart. Journ. Geol. Soc. No. 40. p. 468. For descriptions of the speci-
  

mens of Hippurites brought home by Mr. Loftus, see the Appendix to this Me-