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BRITISH PALAEOZOIC PHYLLOCARIDA. 



Lingulocaeis siLiQuiPOEMis, T. B. Jones. Geol. Mag., 1883, p. 464. 



— — T. B. Jones and H. Woodward. Report Brit. Assoc. 



for 1883 (1884), pp. 215 and 223; ibid, for 

 1888 (1889), p. 177, figs. 8 and 9. 



In the British Museum are casts of the insides of two bivalves (" 48654 " 

 and " I, 2590 ") labelled " Lingnlocaris ; " but, though probably belonging to 

 Mr. Salter's genus here mentioned, they differ much from its first species in 

 outline. They are longer, sharper at one end, and more nearly resembling a pea- 

 pod in shape. This species we have distinguished as L. siliquiformis. 



At p. 223 of the First Report (1883) we described this Cambrian Phyllocarid 

 as differing from Salter's L. lingnlsecomes, as above. One specimen (PI. XIV, 

 fig. 1), rather wrinkled by crush, in bluish-grey slaty mudstone, with rusty 

 facings, from the Upper Tremadoc series at Garth Hill, Portmadoc, was presented 

 to the British Museum by the Rev. J. P. Blake (No. I, 2590). Another (fig. 2), in 

 grey slaty micaceous mudstone, also in the British Museum, is marked " 48654 

 from the schistose Bala rock at Bwlch-y-gaseg, near Cynwyd, Corwen ; J. P., 

 March 14th, 1868." 



3. Lingulocaeis Salteriana, T. R. J. and H. W., 1889. Plate XIV, fig. 3. 



Lingulocaeis Salteriana, T. B. Jones and H. Woodward. Report Brit. Assoc. 



for 1888 (1889), pp. 176 and 177, figs. 6 and 7. 



The British Museum has a fine specimen of one of the old Cambrian Phyllocarids 

 from the Tremadoc-slate series (No. I, 2591). It is a black, shining, and filmy 

 valve (or compressed bivalved carapace), seen as an impression and counterpart 

 on a split slab of hard, dark-grey, micaceous mudstone, which has been subjected 

 to the usual lateral pressure. The valve, 3^ ? X li inches (83 by 28 mm.), is 

 acutely subovate or sharply boat-shaped in outline, convex below and straight 

 above, and was acute probably at each end, though one of them is damaged. It 

 retains a remnant of one of the small, subtriangular, terminal extensions of the 

 dorsal edge, such as are present in L. siliquiformis. See fig. 6 in our Sixth Report, 

 for 1888, p. 178. 



The surface is peculiarly marked with what seem to be modifications of 

 ornamental strise or linear plaits, namely, very small lenticular and bead-like 

 elevations, which may have resulted from raised longitudinal stride being crossed 

 by the delicate plaiting of lateral pressure at slightly different angles. 



We dedicated this fine species to the memory of our friend Mr. J. W. Salter, 



