Paleozoic Phyllopoda, ete. 201 
5. Fragments oF A Poytiocarrp ? Plate X. Figs. 6a, 60. 
This was selected as being possibly an imperfect valve or moiety 
of a Phyllopodous carapace; but we find that the evidences of its 
alliance in any direction are too poor to allow of critical determin- 
ation. Mr. J. W. Salter labelled it ‘‘ Lingula,” possibly with the view 
of its being an imperfect triangular shell, the upper right-hand 
corner in Vig. 6a being regarded as at or near the umbo; the striz, 
however, are not really concentric with that angle. Some effects of 
lateral pressure are seen in the oblique parallel lines crossing the 
lines of growth in Fig. 60. 
Fig. 6 is a black film on black shale, from the Lowest Llandeilo 
beds at Abereiddy Bay, Cardiganshire. British Museum, No. I. 2611. 
6. AprycHopsis WILLIAMSII, sp. nov. Plate X. Fig. 7. 
This is the moiety of a carapace near to those of Aptychopsis ovata,’ 
J. & W., and A. Wilsoni,? H. W., but differing from each in the 
eurve of the outer edge, and in the proportion and angle of the 
nuchal notch. In particular, this valve has a relatively fuller curve 
posteriorly, and is narrower in the upper part, than either of those 
above-mentioned. The uppermost edge has been somewhat damaged, 
like our figure of 4. Salteri, H. W.° 
At first sight, when looked at with its straight edge uppermost, 
this simulates a valve of Ceratiocaris Ruthveniana* with a broken 
anterior end; the striate ornament, however, consists of concentric, 
and not longitudinal, lines, and the posterior extremity is more 
angular. We name it in honour of its discoverer, Mr. G. J. Williams 
of Blaenau Ffestiniog. 
Fig. 7 represents a dark film in dark-grey, rather hard shale, from 
Harp Hollow near Welspool, of Upper-Silurian age. Mr. G. J. 
Williams’ Collection. 
Left valve—Length, 26mm.; Width, 13mm.; Depth of notch, 
about 5mm.; Length of dorsal suture, 22 mm. 
The nuchal notch opens at an angle of about 120°. 
7. CERATIOCARIS INSPERATA, Salter. Plate X. Figs. 8a, 0, c, and 9. 
Oeratiocaris ? insperatus, Salter, Mem. Geol. Surv. vol. iii, 1866, p. 295, woodcut, 
fie. 6; 2nd edit. 1881, p. 486, woodcut, fig. 6. 
In ‘‘Siluria,’’ 3rd (4th) edit. 1867, p. 516. 
—— Catal. C. 8. Foss. Cambridge, 1873, p. 16. 
——— H. Woodward, Catal. Brit. Foss. Crust. 1877, p. 71. 
imsperata, T.R.J. and H. W., Grou. Mac. 1885, p. 466; Brit. Assoc. 
Report for 1885 (1886), p. 3d1. 
— Monograph Brit. Paleoz. Phyllop. part i. 
1888, p. 64. 
H. Woods. Catal. Type Foss. Woodw. Mus. Cambridge, 
1891, p. 184. 
Fig. 8, in a fairly good state of preservation, shows three caudal 
spines (one style and two stylets), and the distal portion of a sub- 
1 Monograph Brit. Palzoz. Phyllop. part ii. 1892, p. 108, pl. 15, figs. 4 and 5. 
* Ibid. p. 105, pl. 15, figs. 12, 15 and 16. 
3 Ibid. pl. 17, fig. 6. 4 Thid. part i. 1888, p. 49, pl. 10, fig. 6. 
