THE NATURAL HISTORY SURVEY. 23! 



occipital furrow and bounding on their outer sides a pair of small 

 ovoid orp yriform basal glabellar lobes. Eyes small, situated near 

 the glabella. Cheeks broad, connected anteriorly by a broad 

 area between the anterior extremity of the glabella and the 

 marginal border. Thorax with well-defined axis, segments 

 10 to 17 with grooved pleura. Pygidium small with a short 

 axis and. depressed pleura. 



Cyphaspis intermedia, n. sp., pi. xx, figs. 3-5. 



Description. Glabella semi-elliptical in outline, about three- 

 fourths the length of the head, rounded in front and truncate 

 behind, strongly convex longitudinally and transversely, sur- 

 rounded laterally and anteriorly by a narrow but well defined 

 dorsal furrow, the bottom of which is a little impressed below 

 the inner margin of the cheeks ; at the base of the glabella are a 

 pair of small but well-defined lateral lobes which extend about 

 half way up the sides of the glabella, they are separated from 

 the main portion of the glabella by the posterior glabellar 

 furrows which originate at the dorsal furrows about two-thirds 

 the distance from the anterior extremity of the glabella to the 

 occipital furrow, they describe a slight curve obliquely backward 

 and inward, meeting the occipital furrow about half way between 

 its middle point and the dorsal furrows; a second pair of lateral 

 furrows are slightly impressed in the sides of the glabella just 

 above the dorsal furrows, just in front of the mid-length of the 

 glabella. The occipital furrow is narrow and shallow. The 

 occipital segment is narrow and flat, its surface being consider- 

 ably depressed below the glabella. The fixed cheeks extend 

 nearly horizontally from the dorsal furrows into the palpebral 

 lobes which lie opposite the outer extremities of the posterior 

 glabellar furrows; in front and back of the palpebral lobes the 

 surface slopes away rather abruptly from the dorsal furrows 

 and is continuous around the anterior extremity of the glabella 

 as a rather broad, slightly convex, sloping area between the 

 dorsal furrow and the marginal border. Marginal border 

 sharply defined and rather broad. Free cheeks not preserved 

 in any of the specimens observed. Thorax and pygidium un- 

 known. Entire surface of the cranidium covered with fine 

 papillae which are more crowded upon the cheeks, being nearlv 

 obsolete upon the marginal border. 



The dimensions of the best preserved specimen, a cranidium, 

 are: length 5 mm., width between the margins of the palpebral" 



