Frof. T. R. Jones — On some Palceozoic FhyUopocla. 355 



of Garth, near Portmadoc, North Wales, are referable to this genus, 

 but do not match any known species. 



7. A. Salteri, H. W., 1882. Geol. Mag. Dec. 11. Vol. IX. p. 389, 

 PL IX. Fig. 19. 



A distinctly-marked species, with ovate outline (when complete) ; 

 from the Upper Silurian of Pencarreg, Caermarthenshire. 



8. Aptychopsis, sp. nov. 



A small transversely oval, or oblate form, with broad notch ; in 

 the Cambridge Museum ; collected by Mr. Marr in the Brathay 

 (Lower Coniston) Flags at Troutbeck, Windermere. 



A similar oblately circular Aptychopsis is in the British Museum 

 from the Gala beds near Moffat. 



XL — Peltocaris, Salter, 1863. Q. J. Geol. Soc. vol. xix. p. 87. 



This Phyllopod was at first referred by Mr. Salter to Dithyrocaris, 

 then to Ceratiocaris ; and at last, as his knowledge of these Crustacea 

 extended, he was enabled to assign it to a proper place with a distinct 

 name. It is discoidal, round or oval, tripartite, with straight median 

 dorsal suture, reaching forward as far as a transverse curved nuchal 

 suture. 



1. P. aptychoides, Salter, 1852. Loc. cit. p. 88 ; and H. Woodward, 

 Q. J. G. S. vol. xxii. 1866, p. 504, pi. 25, fig. Q. 



Several specimens have been got from the Moffat beds (Lower 

 Silurian), and from co. Down, Ireland (Middle or Upper Silurian). 



2. F. anatina, Salter ? 1873. In the " Catal. PalEeozoio Fossils 

 Cambridge," p. 93, this species is mentioned, but as yet it has not 

 been satisfactorily identified. 



3. Peltocaris, sp. nov. 



A small shield, cordate in form without its cephalic piece, is in the 

 British Museum, from the Mofiat beds (L. Silurian) of Wasthope Burn. 



4. Peltocaris, sp. nov. 



A small transversely oval or oblate shield, with very broad notch, 

 like No. 8, Aptychopsis, in general shape, seems to be quite new. 

 From the Lower Silurian Shale of Moffat. Another, like it, but still 

 smaller, is in the Cambridge Museum, from the Coniston Mudstone 

 of Skelgill Beck (Marr). 



5. Peltocaris? Harhnessi, Salter, 1863. In the Quart. Journ, Geol. 

 Soc. voL xix. p. 89, fig. 2, Mr. Salter described a fragment of a 

 carapace which he doubtfully referred to Peltocaris. 



XII. PiNNOCAKis, K. Etheridge, Jun., 1878. P. Lapioorthi, E. E., 

 Jun. Proc. Ptoy. Phys. Soc. Edinb. vol. iv. 1878, p. 167, pi. 2, figs. 

 3-5 ; and '• Fossils of Girvan," 1880, pp. 207, 210, pi. 14, figs. 17-20. 



Some separate laterals of apparently folded or sutured carapaces 

 have been carefully treated of by Mr. K. Etheridge, Jun., as showing 

 Phyllopodous characters. The separated pieces have the shape of 

 valves of the Pinna, broad and rounded at one end, narrow at the 

 other. The lines of growth are concentric with a kind of umbo 

 some way back from the front, about a third of the length of the 

 test. There would be but little room, if any, for a rostral piece, if 

 the carapace were flat ; and possibly it was really bivalve. 



