Vol. 58.] MR. F. R. C, REED ON THE GENUS LICHAS. 79 
glabella is elevated or even swollen into a conical protuberance, 
while the posterior part is depressed. Occipital lobes are present. 
The pygidium has two rings on the axis, a post-axial piece not 
defined posteriorly, and three pairs of pleure, each with a free 
Fig. 15.—Lichas equiloba, Stetnh. (After Schmidt.) 
Uf \ 
a b 
[a from ‘Rev. Ostbalt, Silur. Trilob.’ pt. ii, pl. v, fig. 8a; 
b from pl. v, fig. 10.] 
point and pleural furrow; but the third pleure are incompletely 
defined, and their pleural furrow tends to curve inward to the 
axial, 
Section C, 
L. (Conolichas) equiloba, Steinh. | L. triconicus, Dames. 
Srecrion D. 
A peculiar American species, LZ. Hriopis, Hall, appears to demand 
a section to itself, but it is imperfectly known. Hall put it 
with Conolichas, to which it js undoubtedly allied by the swollen 
anterior portion of the glabella, but in some other respects it shows 
resemblances to Terataspis. [Dr. Giirich, Neues Jahrb. Beilage- 
Band xiv (1901) p. 530, forms the subgenus Hchinolichas for its 
reception. | 
Sxction D. 
L. (Echinolichas) Eriopis, Hall. - | ?L, Bigsbyi, Hall. 
Section EK. (Fig. 16, p. 80.) 
A single species, L. adlenoides, characterizes this section, its pecu- 
liarities of a smooth surface, a pygidium with anterior facets and 
rounded margin, and the absence of all indications of pleura (except 
in the cast) on the lateral lobes, being quite sufficient to separate it 
from all others in Group II. 
SEcTION H. 
L. (Leiolichas) illenoides, Nieszk. 
