ORDOVICIAN FAUNAS. 205 
outline, the eyes small. Facial suture starting at the lateral margin, 
and after extending inward toward the glabella, making a sharp turn 
forward just back of the eye, and after passing around the eye, cury- 
ing gently forward, cutting the anterior margin of the head in front 
of the glabella. Glabella prominent, convex, broadest in front, ex- 
tending nearly to the anterior margin of the head. Glabellar fur- 
rows well defined, but not extending across the glabella. The two 
anterior pairs straight, each portion extending over about one-fourth 
the width of the glabella. ‘The third pair extending inward about 
as far as the other two, and then bending abruptly backward and 
joining the occipital furrow, leaving the posterior glabellar lobes more 
or less detached. Occipital furrow deep and well defined, arching a 
little forward upon the glabella, extended laterally upon the fixed 
cheeks nearly to the lateral margins, where it joins a marginal fur- 
row just in front of the genal spine, which passes anteriorly. Occi- 
pital segment well defined. Dorsal furrow rather sharply impressed. 
Fixed cheeks convex, their posterior lateral angles extended into 
prominent, curved, genal spines. Whole surface of the head, except 
the dorsal, glabellar, occipital and marginal furrows, strongly granu- 
lose or papillose, with some scattered tubercles larger than the others. 
Thorax and pygidium not recognized in the New Jersey collections. 
Remarks.—This species is more or less abundant in the Trenton 
limestone throughout the United States wherever this formation 
occurs, but 1s rarely preserved, except in a fragmentary condition. 
The New Jersey material consists entirely of fragmentary portions. 
of the head; in most cases the glabella alone being recognized. This 
need never be mistaken, however, even in its fragmentary condition, 
because of its peculiar granulose ornamentation. 
PSEUDOSPHAEREXOCHUS TRENTONENSIS Clarke. 
Plate XV., Figs. 24-25. 
189%. Pseudospherexochus trentonensis Clarke, Pal. Minn., pt. II. 
p. 734, figs. 53-54. 
7 
Description.—Glabella subhemispherical, a little wider than long, 
with three pairs of distinct glabellar furrows. The first pair is the 
shortest, originating close to the frontal margin, the length of each 
