208 PALEONTOLOGY OF THE EUREKA DISTRICT. 
description of the species being based on portions of the cephalic shield and 
entire specimens of the pygidium. 
The glabella is subclavate, moderately convex, and separated from the 
fixed cheeks by a well-defined furrow; anterior lobe composing more than 
half of its entire area, transversely subovate, the length being two-thirds of 
the width; lateral furrows distinctly defined, deepest at the inner end; the 
anterior furrow extends obliquely forward and the two posterior pairs have 
a slight inclination backward; this gives to the anterior lateral lobe a 
narrow base and wider terminal portion, or a subtrigonal form to the lobe; 
the two posterior lobes are shorter and with their sides subparallel to each 
other. Occipital segment slightly rounded, almost flat on the upper portion 
in the cast, broadest at the center, narrowing slightly towards the dorsal 
furrows; occipital furrow strongly defined, arching a little forward at the 
center. Fragments of the fixed cheeks and palpebral lobe, with a free 
cheek found associated with them, show a large reniform eye situated oppo- 
site the anterior lateral lobe of the glabella with a deep furrow extending 
around its base; the slope from the eye to the shallow marginal groove is 
quite abrupt and gives considerable convexity to the head; the outer margin 
is of medium width, with a gentle slope outward. 
Hypostoma subtriangular, as wide anteriorly as long, moderately con- 
vex; anterior margin gently curved; lateral margins contract quite rapidly 
at the anterior lateral angles and then converge regularly to the posterior 
extremity, where they converge very abruptly, forming an obtuse point 
which has several short spines or points along its lateral margins; a sulcus 
that rises on the lateral margin curves backward, and unites with its fellow 
at the center three-fourths the distance from the anterior to the posterior 
extremity; a broad shallow groove crosses anterior and subparallel to this, 
giving a lobed appearance to the posterior half of the hypostoma. 
Thorax: A cast of asingle segment is all that occurs associated with the 
other parts of this species; the median lobe is moderately convex and 
nearly transverse; lateral lobe curves outward and a little backward, ter- 
minating in a rather abrupt point; pleural groove deep, crossing the seg- 
ment obliquely from the anterior margin to the posterior outer angle. 
13 Dalmania, Emmerich, 1845; modified by Barrande to Dalmanites in 1852. 
