448 DE. G. J. HINDE ON NEW FOSSILS [Aug. 1896^ 



III. On the Jaw-appakattjs oe an Annelid (Eunicites Reidi^v 



SP. NOV.) FROM THE LOWER CARBONIFEROUS OF HaLKLN MOUN- 

 TAIN, Flintshire. (PI. XXII. figs. 2, 2 a, & 2 e.) 



In the numerous examples of the jaw-plates of annelids described 

 by the writer some years since from the Palaeozoic rocks of Canada, 1 ' 

 England, 2 Scotland, 3 and the Isle of Gotland, 4 without exception the 

 small constituent plates of the jaw occurred separately on the rock- 

 surfaces, detached from the relative positions which they occupied 

 in the living condition of the animal. These small bodies have 

 subsequently been discovered in the Upper Silurian rocks of New 

 South Wales by Mr. Eobert Etheridge, 5 and in the Middle Devonian 

 of New York State by Dr. J. M. Clarke, 6 and always in a similarly 

 detached condition, with the single exception of the jaw- apparatus* 

 of a species of Arabellites, discovered by Dr. Clarke, in which the 

 different dentated plates, now somewhat fragmentary, are shown 

 in the natural position that they occupied in the jaw-sac of the- 

 animal. 



I propose now to describe another and more perfect specimen 

 than that just referred to, in which the upper jaw-plates of a 

 species of Eunicites have been preserved, showing their natural- 

 position with respect to each other. The specimen in question was 

 discovered by Miss Margery A. Reid in some thin black fissile 

 shales of the Lower Carboniferous formation at Halkin Mountain,- 

 Flintshire. In splitting open a piece of the shale the jaw was- 

 found standing out in relief on the surface of one piece and the- 

 counterpart on the other. A portion of one of the large pincers 

 and of one of the dental plates must have been broken away when 

 the shale was splintered ; with these exceptions the jaw-apparatus 

 differs but little in appearance from that of a recent annelid. It 

 has precisely the same glossy black aspect as the upper jaws of 

 recent annelids, and, like these, must have been originally of 

 chitinous material. 



As now exposed, the jaw-apparatus shows its upper or free 

 surface. It consists on each side of a support, pincer, and dental 

 plate ; probably paragnaths were also originally present, but only a 

 single one of these has been found. The entire length of the jaw is 

 5*4 mm., and its greatest width 4*1 mm. The supports a (PI. XXII, 

 figs. 2 & 2 a) are approximately oblong in outline, with a straight 

 upper margin where they come into contact with the base of the 

 pincer, nearly straight sides, and rounded ends. The surface has a 

 slightly elevated ridge, which runs obliquely. They are now about 

 1*2 mm. in length by "7 mm. in width. It is probable that they wero 

 longer than is now shown, judging from an impression on the shale r 

 which indicates that they were originally prolonged to a blunted 



1 Quart. Journ. Geol. Soc. vol. xxxv. (1879) p. 370. 



2 Ibid. vol. xxxvi. (1880) p. 368. 3 Ibid. vol. xxxv. (1879) p. 386. 



4 Bihang till k. svenska Vet.-Akad. Handl. vol. vii. (1882) no. 5. 



5 Geol. Mag. 1890, p. 339. 



6 Sixth Annual Eeport of the State (New York) Geologist, for the vear 1886.. 

 Albany, 1887. 



