122 
BULLETIN OF THE LABORATORIES 
furrow, their diameter is about two-thirds of the distance which sepa- 
rates them, or but slightly less. The groove defining these lobes, the 
occipital furrow, the groove separating the fixed cheeks and then de- 
fining the anterior margin of the glabella are all very distinct. The 
facial sutures begin to define the fixed cheeks at a point near the 
upper margin of the lateral lobes of the glabella, then they pass within 
a moderate distance of the lateral lob^s to a place slightly behind the 
middle of these lobes, after which they turn quite abruptly outward 
and then curve backward to the posterior margin of the head. At a 
point rather beyond the middle of the occipital border of the fixed 
cheeks, near the edge, there is a low tubercle. On each side of the 
glabella are two faint grooves which are readily overlooked, especially 
in casts. When examined however with a magnifier, and with the 
light thrown in the proper direction, they are really quite distinct. 
I'he first pair lie about two-thirds the diameter of ihe lateral lobes 
above their anterior margin; the second pair he about the same dis- 
tance beyond the second. Being short they are not readily seen in a 
view from above. The head parts of the Ohio specimens are therefore 
seen to agree perfectly with those ol the European Sph. minis. 'Fhe 
pygidium associated with the Wisconsin species l)elongs to Ceraiiriis 
Niagarensis, as Hall himself afterwards noted. We fail therefore to 
discover what the distinguishing features of Sp/i. Romingeri are, but 
Ohio specimens at least belong to Sph. minis. 
UPPER SILURIAN.— A USTRA LIA. 
EnCRINURUS B^OWNINGI, sp. 11. 
{Plate XIII, Fig. 7 .) 
The glabella is very much rounded and inflated for about two- 
thirds its length anteriorly, the posterior third is much narrower, about 
half the greatest width of the anterior parts, slightly widening behind, 
thus giving a marked concave outline to the sides of the glabella. The 
occipital furrow is itself not very deep, but the border behind it is ele- 
vated to such a degree as to give it some importance. Along the pos- 
terior lialf of the glabella the tubercles are arranged in quite distinct 
transverse rows. In the specimen figured, the first three rows have 
