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- 

 moir. 



