130 



BRITISH PALAEOZOIC PIIYLLOCARIDA. 



II. DESCRIPTION OF THE SPECIES. 



1. DiTHYROCARis GLABRA, Woodwavd and Etheridge, 1873. Plate XVIII, figs. 1, 2 ; 



Plate XIX, figs. 1—4 ; Plate 

 XXIII, fig. 11 ; Plate XXV, 

 figs. 1, 2. 



DiTHTEOCAEis GLABRA, H. Woodward and B. Etheridge, jun.,^l%Td. Mem. Geol. 



Surve}^ Scotland, Expl.an. Sheet 23, 

 Appeudix, p. 99. 



— — H. Woodward and R. Etheridge, jun., 1874:. Geol. Mag., 



dec. '2, vol. i, p. 108, pi. v, figs. 4 and 5 ; Keport 

 Brit. Assoc, for 1873 (1874), Sect., p. 92. 



— — J. Armstrong, 1876. Catal. W.-Scot. Fossils, p. 45. 



— — H. Woodward, 1877. Catal. Brit. Foss. Crust., p. 73. 



— — Bigsbg, 1878. Thesaur. Dev.-Carb., p. 249 



— — J. Coutis, 1884-5. Trans. Geo). Soc. Glasgow, vol. vii, 



pp. 200 and 327. 



— — E., W., and J., 1887. Eep. Brit. Assoc, for 1886, p. 64. 



— — Etheridge, 1888. Foss. Brit., vol. i, Pateoz., p. 238. 



Size. — The following are the measurements of the two half-carapaces (PI. 

 XVIII, figs. 1 and 2) as given in the 'Geol. Magazine,' 1874, p. 109, for pi. v, 

 figs. 4 and 5 : 



Large halt-carapace 



Greatest breadth 

 Greatest length 

 Length along the dorsal line 

 Breadth of anterior notch 

 Depth of anterior notch 

 Breadth of posterior notch 

 Depth of posterior notch 



(fig. 4). 



25 mm. 

 62 „ 

 40 „ 

 10 „ 



7 „ 

 23 „ 

 15 „ 



Smaller lialf-carapace 

 (fig. 5). 



22 mm. 



55 



30 



12 



10 



20 



15 



Specific Characters. — Valves (or moieties of carapace) elliptical ; smooth except 

 for a granulated antero-dorsal area, the granules sometimes extending over the 

 dorsal area. Dorsal junction of the valves overridden by a rugose ridge, like a 

 closely set row of ridge-tiles (PI. XXV, figs. 1 and 2). Sometimes there is a faint 

 indication of a mesolateral ridge (PI. XIX, figs. 1 and 3). 



Abdominal segments exposed, few ; trifid appendage of strong style and 

 stylets of nearly equal length (PI. XIX, fig. 3; and PL XXIII, fig. 11). 



' The joint authorship is mentioued at p. 98. 



