486 Synopsis of Species of Carboniferous Limestone Trilobites. 
moderately small, smooth; margin of cheeks smooth, produced into 
rather long cheek-spines (“long flat striated spines,” Portlock’) ; 
margin of head-shield incurved, finely striated; thoracic segments 
nine in number, axis strongly arched, each segment having a 
narrow elevated central rib ornamented with about twelve small 
tubercles or spines, with a smooth anterior articular portion and a 
less elevated posterior border; the pleure are strongly grooved and 
are bent down at the fulcral point, their extremities being faceted 
and obtusely pointed. Pygidium composed of from twelve to fifteen * 
coalesced segments; axis strongly arched and ribbed, like the thorax, 
but no ornamentation visible ; side-lobes of pygidium also arched ; 
the ribs running to the border; a wide striated margin is exposed 
where decorticated. 
Formation.—Carboniferous Limestone. 
Locality.x—Carnteel, Tyrone, Ireland. 
The specimen figured is preserved in the Museum of Practical 
Geology, Jermyn Street, and is unique. 
GRIFFITHIDES cALcARATUS, M‘Coy, sp., 1844. 
Griffithides calearatus, M‘Coy. 1844, Synop. Carb. Foss. Ireland, p. 160, pl. iv. 
fig. 3 
mucronatus, ei wood: 1877. Cat. Brit. Foss. Crust. p. 37. 
calcaratus, V. von Moller. 1867. ‘Trilob. der Steinkohl. p. 19. 
——_——— H. Woodw. 1883. Pal. Soc. Mon. Carb. Trilob. pt. i. p. 38. 
This species was proposed by Prof. M‘Coy in 1844, for a specimen 
from Ireland of which he figures the head only, but describes the 
head and tail also. We have not been so fortunate as to see the 
original of M-Coy’s figure, but we give his own description as 
follows :—‘ Cephalo-thorax semioval; glabella smooth, ovate, most 
convex in the middle of its length; cheeks small, triangular, flat, 
smooth; wings strongly striated, broad, prominent, rounded, termi- 
nating posteriorly in long, flattened spines; eyes moderately lunate 
(smooth ?), connected with the glabella by a nucleus on each side; 
pygidium with a smooth margin, each segment with a row of very 
minute granulations. 
This beautiful species is most nearly allied to the G. longispinus, 
of Portlock, but is at once distinguished by its smooth cheeks; the 
eyes also, in the present species, are differently formed and placed, 
and the glabella is much smaller and less prominent in front. 
Length of glabella five lines, greatest width three lines; width at 
base one line, width of cephalo-thorax seven lines; length of eyes 
one and a half lines, width one line; length of posterior alar spine 
three lines. The pygidium has a broad, smooth margin or limb, in 
which it differs from that of G. longispinus, in which the segments 
are extended to the margin; there are a single row of very minute 
granules on each segment. Width of pygidium five lines” (op. cit. 
p- 169). 
1 There is reason to conclude that one of these spines existed when Portlock wrote 
his description, although it is only now indicated by a fragment and by the scar 
where it once rested. ; | 
2 The extremity is injured, so that the exact number cannot now be ascertained. 
