CRUSTACEA. 
78 
LICH AD^. 
LICHAS, Dalman. 1826. 
[s.-G.] TERATASPIS, Hall. 1863. 
Lichas (Terataspis) grandis. 
1>LATE XVII, FIGS. 1-6; PLATE XVIII, FIGS. 1,2; PLATE XIX, FIGS. 1-7. 
Lichas grandis. Hall. Descriptions New Species of Fossils, etc., p. 82. 1861. 
Lichas grandis. Hall. Fifteenth Kept. N. Y. State Cab. Nat. Hist., p. 110. 1862. 
Lichas grandis, sub-genus? Terataspis, Hall. Sixteenth Kept. N. Y. State Cab. Nat. Hist., p. 223. 1863. 
Lichas supei'bus, Billings. Canadian Naturalist and Geologist, vol. vii. No. 4, p. 239. 1875. 
Acidaspis {Terataspis) grandis, Hall. Illustrations of Devonian Fossils, pis. xvii, xviii. 1876. 
Cephalon very prominent in front, abruptly depressed behind; length to width 
between the eyes as 5 to 4; to greatest width as 5 to 7. Frontal border 
broad, flat and sloping outward; margin not thickened. 
The facial sutures begin on the posterior margin a short distance outside 
the axial furrows, and slope obliquely forward, curving abruptly and passing 
thence directly inward to the eye; thence directed outward in a broad curve 
to the anterior margin. 
Glabella sub-quadrate in general outline; anterior lobe ovoid or ellipsoid, 
extremely prominent, tumid, evenly convex and strongly constricted about 
the base; length equal to five-eighths the length of the glabella; length to 
width as 6 to 5. Longitudinal furrows very broad and deep, merging at the 
posterior margin of the frontal lobe, and forming a broad, median depression, 
which narrows for a short distance and widens thence to the occipital ring. 
The two lateral lobes are broad, directed posteriorly, and at the summit each 
one is produced into a conspicuous compound spine, the inner branch of which 
is the longer, reaching beyond the height of the anterior lobe, and projecting 
over the occipital ring. These lateral lobes may be regarded as the coalesced 
first and second pairs, the third pair being obsolete or indicated only by a 
faint elevation of the crust near the occipital ring, crowned by a few strong 
