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BRITISH PALEOZOIC PHYLLOCARIDA. 



British. 8. A. ovata, sp. nov. PI. xv, figs. 4 and 5. Ovate. Middle Silurian. 



— 9. A. Salteri, H. "W. PI. xvii, fig. 6. Suboval. tipper Silurian. 



— 10. A. subquadrata, sp. nov. PI. xv, fig. 20. Subquadrate. Lower Silurian. 



— 11. A. angulata (Baily). PI. xv, fig. 19. Oblate. Lower Silurian. 



— 12. A. oblata, sp. nov. PI. xv, figs. 21, 18, 23. Deeply oblate, wide. Middle Silurian. 



No Goniatites have been found with any of these. 



We propose in the first place to propound the characters and history of 

 Barrande's typical species A. prima, no exact representative of which we have 

 yet met with in Britain. 



1. Aptychopsis prima, Barrande, 1872. Woodcuts : Fig. 7; and Fig. 10, p. 109. 



Apttchopsis primus, Barrande. Silur. Syst. Centre Boheme, vol. i, Supplem., 



1872, p. 457, pi. xxxiii, figs. 1 — 21 [A. prima, 

 var. secunda, Ac.]. 



— — Romer (after Barrande). Leth. Oeogn., 1876, pi. xix, 



figs. 3 a, 3 6. 



A. peima et var. secunda, T. R. J. and H. W. Geol. Mag., 1884, pp. 349 and 354. 

 — — — Eeport Brit. Assoc. for 1884 



(1885), pp. 79 and 89. 



Aptychopsis prima includes, according to M. Barrande (op. cit.), round, 

 subcircular, oval, and obovate forms of the tripartite shield-like test, which both 

 Barrande and H. Woodward termed Aptychopsis independently in 

 in the same year (1872). Among the figures (when completed in 

 outline) on pi. 33, of ' Syst. Sil. Boheme,' vol. i, Supplem., 

 circular or subcircular forms are represented by figs. 1 — 9, 13 — 15, 

 and 18; and more or less obovate tests by figs. 11 (obovate) ; 10, 

 fig. 7.— Spc 12, 16, 19 — 21 (broad-obovate) ; and 17 (oval). Thus there are 

 cwis ° f pifma, f° ur somewhat different shapes among these figures. 

 Bubowitz Bohe" ^ n ^h e British Museum (Natural History) are some specimens 

 Britilh'Mif^m 1 labelled by M. Barrande many years ago, as " Aptychus ? primus 

 (I, 2587) " and " Aptychus ? secundus (I, 2588)." The former, when 

 perfect, with the two lateral moieties and the frontal (cephalic or rostral) piece 

 in place, were broad-obovate (woodcut, Fig. 7) ; and the latter (when perfect) were 

 nearly or quite round. Evidently our deceased friend had decided to group 

 these two kinds together, by the time he published the Supplement of the 

 first volume of his great work treating of these and other Crustaceans. The 

 circular shields found in Bohemia are chiefly from the schistose or slaty mudstone 

 of Borek, with some from Litohlow and Kozel, — all in Etage " E, el " ; and the 



