126 
BULLEI’IN 0F THE LABORATORIES 
observed in ours; indeed it suggests in this our first species, but the 
anterior of the glabella is not round; the drawing evidently leaves 
much to be desired) , and the greater distance of the eye from both 
dorsal and occipital furrows. 
Phacops serratus, sp. n. 
{Plate XIII, Fig. I.) 
Head with semi-circular outline, almost twice as broad as long. 
Anterior lobes of the glabella equalling eight-elevenths of the length of 
the head; its anterior margin, instead of being regularly rounded as is 
usual in most species of Phacops, is rounded most at the middle of its 
outline and at its junction with the dorsal furrow, giving the interme- 
diate outline on each side a somewhat compressed appearance. The 
curvature of the sides of the glabella is small, they converge posteriorly 
and form an angle of about seventy five degrees with each other. 
With the exception of a faint median elevation the surface is quite flat, 
above bending rather abruptly into the dorsal furrows and at the anter- 
ior margin even becoming incurved. The specimen is slightly 
exfoliated so that it is impossible to say if there were any grooves on its 
surface, but if so they must have been rather inconspicuous. It is 
covered however with low small tubercles. This lobe of the glabella 
is defined posteriorly by a furrow which is quite marked at the sides, 
but toward the middle it becomes very shallow forming a sort of axis, 
and curving more or less forwards. This furrow cuts off from the 
remainder of the glabella two small posterior lobes, at either side con- 
siderably depressed below the general level of the glabella and 
terminated with a small knob, posteriorly it is defined by the well 
marked occipital furrow. 'The occipital ring is very broadly subtrian- 
gular and is terminated with a distinct, short, pointed projection, 
which repeats itself on all the segments of the axial lobes of the thorax, 
gradually becoming indistinct, and vanishing soon after reaching the 
first ring of the axial lobe ot the pygidium. 'Fhe eye has a reniform 
outline and extends from a short distance behind the point of greatest 
width of the glabella to within a short distance of the continuation of 
the occipital furrow. The palpebral lobe is strongly defined by^a very 
distinct furrow which also outlines the posterior parts of the. eye. 
