THE NATURAL HISTORY SURVEY. 265 



elliptical in outline, occupying nearly one-half of the entire gla- 

 bella; first and second lateral furrows directed at right angles to 

 the axis and reaching less than one-fourth of the distance across 

 the glabella; first and second lateral lobes of equal width at the 

 margin of the glabella; third lateral furrows stronger and deeper 

 than the others, directed obliquely backward, continuing 

 across the glabella and becoming confluent with the occipital 

 furrow in the middle so that the third lateral lobes are isolated 

 as sub-triangular nodes. Occipital furrow about equaling in 

 strength the third lateral glabellar furrows, directed forward 

 from the lateral margins of the glabella and becoming confluent 

 with the third lateral furrows in its median portion. Occipital 

 segment flat, broadest in the middle. Cheeks moderately con- 

 vex with a flattened marginal border which is produced into the 

 genal spines and which is continued around the anterior extrem- 

 ity of the glabella. The lateral marginal furrows make a sharp 

 turn near the genal angles and extend to the dorsal furrow par- 

 allel with the posterior margin of the head, leaving a narrow 

 posterior marginal border. Palpebral lobes of moderate size, 

 scarcely elevated above the general surface of the cheeks, sit- 

 uated opposite the anterior lateral furrows of the glabella. 

 Free cheeks small, triangular. The posterior limbs of the facial 

 sutures extend directly outward to the margins of the head, the 

 anterior limbs describe a convex curve nearly parallel with the 

 margin of the frontal lobe of the glabella to the anterior margin 

 of the head. 



Thorax with eleven segments; the axis moderately convex, 

 occupying about one-third of the entire width, its sides nearly 

 parallel, bounded by well-defined axial furrows. The pleura 

 slightly convex. On each side of the axis a slight furrow nearly 

 parallel with the axial furrow and lying about one-third the dis- 

 tance between it and the lateral margin, extends the entire 

 length of the thorax. Between the axial furrows and these 

 lateral furrows, each segment of the thorax is grooved, the grooves 

 starting at the axial furrow from near the anterior margins of 

 the segments and directed obliquely backward nearly to .their 

 posterior margins. 



Pygidium very short with two conspicuous backwardly 

 pointing spines; the axis sub-triangular with four segments, 

 reaching nearly to the posterior margin; pleura indistinctly 

 divided into three segments, the anterior ones being much the 

 largest and slightly grooved near the axial furrows, they are 

 produced posteriorly into the strong spines which are directed 



