Crusracea.] UPPER PALAOZOIC ARTICULATA. 183 
Position and Locality—Common in the shales of the Derbyshire limestone. 
Explanation of Figures. —P1\. 3. D. fig. 10. Part of cephalic shield, natural size—Fig. 11. Pygidium 
of ditto, natural size—Fig. 11a. Two segments of pygidium magnified. 
Subgenus. PHILLIPSIA (Port.) 
Gen. Char.—Elongate oval; buckler semielliptical, with produced lateral angles ; glabella subcylindrical 
not contracted at base, marked on each side by three curved segmental furrows; eyes large, reniform, distinctly 
reticulated ; ¢horqa of nine segments, having pleural grooves and distinct facets ; pygidium semioval, axis and 
lateral lobes with distinct segmental furrows, those of the latter duplicate at their ends, and with an entire 
smooth margin. 
The great comparative width of the base of the glabella, the distinctly marked three pairs of segmental 
furrows, and delicate outer cornea of the eye exposing the reticulation, easily distinguish this genus from 
Griffithides. 
PHILLIPSIA GEMMULIFERA (Phill. sp.) 
Syn. and Ref—Asaphus gemmuliferus Phill. Geol. York. Vol. II. t. 22. f. 11. 
Sp. Ch.—Pygidium semielliptical, average length five lines, width six and half; axal and lateral lobes equal, 
very tumid ; margin flat, smooth, half a line wide; axal segments fifteen, with six regular, longitudinal rows of 
tubercles, the two middle rows strongest ; lateral lobes with twelve segments, the anterior ones with six 
indistinct, irregularly unequal rows of granules, that along the middle of the lobe strongest and continued 
to the apex, the other rows shorter and smaller. 
The head and thorax of this species are not yet known. 
The pygidium resembles that of the P. truncatula, but is distinguished by its constant smaller size, being 
more convex, and the inequality of the rows of tubercles, particularly on the lateral lobes. 
Brongniart’s figure, t. 4. f. 12, supposed by Phillips referrible to this species, really represents a pygi- 
dium neatly distinguished by its four regular rows of large granules on each lobe. 
Position and Locality.—Rare in the carboniferous limestone of Derbyshire. 
Paruuirsta Jones (Porth.) 
Ref.—Portlock. Geol. Rep. t. 11. f. 3. 
Sp. Ch.—Entire animal twice as long as wide; glabel/a oblong, rather more than one-third the entire 
length, very broad, depressed, obtusely rounded in front, contracted in the middle, width at base three fourths 
of its length, excluding the neck-segment ; eyes large, reniform, more than half the length of the glabella ; 
cheeks small, narrow, slightly convex; surface covered with rather distant impressed puncta; thorax and 
pygidium smooth. Average length of cephalic shield three and half lines, width four and half lines. 
This species is extremely common in the red fish-beds of the lower carboniferous limestone of Armagh, 
but is very rare elsewhere, and the only British example I have seen is the head in the collection. It is 
easily distinguished by the very broad, depressed glabella, which is slightly hour-glass shaped, being remark- 
ably contracted in the middle. 
Position and Locality—Rare in the red carboniferous limestone of Arnside, Kendal. 
PHILLIPSIA SEMINIFERA (Phill. sp.) 
Ref. and Syn.—Asaphus seminiferus Phill. Geol. Y. Vol. II. t. 22. f. 8, 9, and 10. 
Sp. Ch.—Head, thorax, and abdomen, of nearly equal lengths ; head semicircular ; glabella semicylindrical, 
very convex, rounded in front, which is slightly narrower than the base ; neck-segment very large ; anterior 
pair of segmental furrows very short, slightly oblique, posterior pair very large, strongly impressed, semi- 
circularly curved inwards and backwards nearly to the neck-furrow, enclosing a large longitudinally oval 
