186 BRITISH PALEOZOIC PHYLLOCARIDA. 



This specimen is embedded in a bard black shale of the Cement-stone, 

 micaceous and calcareous, containing obscure small Ostracods. It is associated 

 with three other pieces of the same shale, including its counterpart ; ni 4269 ' 

 shows another, but imperfect trifid; m 4270 ' contains the fragment of a small 

 dorsal rugose ridge. This is 15 mm. long, and represents probably two-thirds of 

 the original, and is evidently the relic of some small or immature carapace, only 

 about 20 mm. in length. 



1 



13. DiTHYEOCARls DuNNii, sp. nov., J. and W. Plate XXIII, figs. 9 and 10; 



PI. XXIX, figs. 1 and 2. 



PI. XXIII, figs. 9 and 10. Dunn Coll., \^ and \^. (Redesdale.) 



/'Stylo 10 mm. long; 6 mm. broad at top (head or caudal 

 Size.— Fig. 9 {\^) j plate). Ventral ? aspect. 



^ Stylets broken (fragments 11 mm. long). 

 /- Style 10 mm. long ; 5 mm. broad at top (head or caudal 

 „ Fig. 10 (-\^) < platej. Dorsal aspect. 



^ Stylets broken (fragments 8 mm. long). 

 Sj^ecific Gharaders. — The two specimens (figs. 9 and 10) serve as the type of 

 the species. They were collected by Mr. John Dunn, of Redesdale, from the 

 "deaf" nodules in the Redesdale shales.' A part of the last abdominal segment, 

 much crushed, is retained in each specimen, smooth, with a broad, flat, trifid tail 

 attached. They are j^eculiar on account of the broadly triangular style and the 

 narrow stylets, originally rather longer than the style, and obscurely sulcate. 



PI. XXIX, fig. 1. Mus. Geol. Surv. Scot!., F ^^, No. 16. (Larriston Burn.) 

 fig, 2. Mus. Geol. Surv. Scotl., F 'i. No. 19. (Harelow Hill 

 Quarry.) 

 . j" Style imperfect, 20 mm. long ; 7 mm. wide at the toj). 



l Stylet (the most perfect) 30 ram. long. 



/■Style imperfect, 30 mm. long (not much longer originally); 10 

 ,, Fig. 2 < mm. wide at the top. 

 ^ Stylets broken. 

 Characters. — These two imperfect specimens, though much larger, seem to be 

 closely related to D. Dnnnii (PI. XXIII, figs. 8 and 9), by the relatively short and 



' See page 176. The ironstone nodules in the uppermost bed of shale are called "deaf" when 

 they have become oxidised. 



