344 Description of several new Trilobites. 
The second series of ribs, which proceed beyond the costal arches 
of the Crypheus, we suppose will distinguish it from every other 
described genus. 
Cryeuxus Boothii. Green. 
Clyped a antice rotundato; oculis magnis; rugis tribus in fronte 
lateralibus ; articulis septemdecim ; cauda serrata utrinque in denti- 
bus quinque divisa. 
The general contour of this trilobite is that of an elongated oval ; 
the body projects in high relief above the rock on which it reposes, 
and its whole length is rather more than two inches. The buckler 
in our specimen is partly wanting, but the front and one of the 
cheeks are still in a good state of preservation, and afford a pretty 
accurate idea of the whole head. 
The front rises above the surface of the cheeks, is rounded and 
broad at its anterior part and gradually tapers towards the middle 
lobe of the abdomen. It is distinctly divided from the cheeks, and 
has three furrows on each side, near its upper edge. The lower 
furrow is the longest, and is nearly on a line with the inferior edge 
of the oculiferous tubercles on the cheeks. The middle furrow is 
the smallest, and appears as a deep depression or pit. The upper 
furrow is rather above the superior edge of the eyes. The anterior 
margin of the front is marked by a long curved sulcus, which has 
the appearatice of a lip, as in the Calymene of BuumenBacu. 
e cheeks are in the form of spherical triangles. The oculife- 
rous prominences are close to the front, and are . placed just within 
the internal obtuse angles. The reticulated structure of the eye 1S 
quite perfect on the lower portion of the tubercle which still remains- 
We have described the above as the head of our trilobite, though 
it is detached from the body; but as it lies in the rock just belore 
and in contact with the anterior portions of the animal, there can be 
je doubt that it once formed a part of it. 
e articulations of the abdomen and tail cannot be singed 
“each other; seventeen’ may be readily counted, and 
