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BRITISH PALEOZOIC PHYLLOCARIDA. 



long ; the breadth of the single valve, 18 ? mm. ; slope of the angular suture, 

 16 ? mm. at 30° ; breadth or gape of the nuchal notch, 29 ? mm. ; depth of notch, 

 12 ? mm. ; angle of the notch 120°. The two valves united would have a 

 sagittate outline ; and the whole carapace would be acute-obovate in shape. The 

 proportion of width to length as 28 to 43 (?). 



A. Barrandeana occurs in a black softish shale ; and is flattened, cracked, and 

 slightly pyritous. The concentric rings are rather broad ; narrower at the outer 

 margin, and close together at the inside (sub-central) angle. 



From Dobbs Linn, Moffat. 1 In the Museum of the Geological Survey of 

 Scotland, marked M 4418. (The classification of the successive formations in the 

 Moffat district and vicinity has been worked out by Professor Dr. C. Lap worth, 

 F.R.S., see ' Geol. Mag./ vol. ix, 1874, pp. 533—6 ; ' Quart. Journ. Geol. 

 Soc.,' vol. xxxiv., 1878, pp. 240—346 ; and ' Proceed. Belfast Nat. Field-Club,' 

 ser. 2, vol. i, part 4, Appendix IV, 1878 ; also ' Catal. "Western- Scottish Fossils,' 

 by Armstrong, Young, and Robertson, 1876, p. 24, and ' Geol. Mag.,' 1889 

 (dec. 3, vol. vi), pp. 20 — 24, 59 — 64. Although numerous Phyllopod shields 

 have been met with, no Goniatites have been recorded from these beds.) 



PI. XV, fig. 14, an elliptico-triangular left valve, rounded (probably from damage) 

 at the angles. It is near A. Barrandeana in the straight slope of the posterior 

 margin ; but is shorter and proportionally broader. It may be regarded a variety 

 (brevior) of that species. Measurements: | , 18 (?) mm.; — , 12 mm., A, 7 (?) 

 mm. at 40°; 10 (?) mm.; I, 7 (?) mm.; V, 100°. Two valves sagittate; 

 perfect carapace, obovate, tapering downwards, or long cordiform, with a wide 

 shallow notch above. Proportion of width to length about 24 to 25. 



In black, thin mudstone. Valve thin, black, shiny, crumpled, and cracked. 

 Concentrics broad, and crossed by numerous delicate, raised, rugulose striae, 

 radiating from the inner angle; these are comparable 2 with those shown on 

 Barrande's figs. 4, 18, and 20, pi. 33, op. cit. s and p. 457. This form approaches 

 Barrande's fig. 19 in size, but the latter is broad-obovate and subcircular, whilst 

 our fig. 14 does not affect the circular shape, being slanting and narrowed on its 

 posterior third, like PI. XV, fig. 1. It is referred to in the 'Report Brit. Assoc' 

 for 1884 (1885), p. 91. 



Moffat beds ? British Museum. I, 2585. 



Note. — PI. XV, fig. 1, is comparable with fig. 3 in the plate illustrating Mr. J. 

 M. Clarke's paper on " New Phyllopod Crustaceans from the Devonian of Western 

 New York," in the ' American Journal of Science,' 3rd Series, vol. xxiii, 1882, 



1 This locality is described by Prof. Lapworth in the ' Quart. Journ. Geol. Soc.,' vol. xxxiv, 

 pp. 247, 300, 310, 313. 



2 Also with the ornament in Pterocaris Bohemica, Barrande, op. cit., p. 464, pi. xxv, figs. 25 and 

 26, a unique fossil of a different alliance. 



