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 a single 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 Barraude to Dalmanites in 1852. 



