230 THE CHICAGO ACADEMY OF SCIENCES. 



backward towards the occipital furrow, nearly surrounding the 

 very small posterior lateral lobes. Occipital furrow deep and 

 strong, the anterior slope nearly vertical, the posterior slope 

 less abrupt. Occipital segment narrow. Cheeks broad, their 

 anterior slope nearly vertical from the eyes, the lateral slopes a 

 little less abrupt, differentiated laterally and anteriorly into a 

 well-defined marginal border which is separated from the gla- 

 bella in front by a deep indentation beneath the protuberant 

 frontal lobe; posterior margins marked by posterior cheek fur- 

 rows which extend laterally front the occipital furrow. Fixed 

 cheeks narrow; anterior limb of the facial suture nearly straight, 

 the posterior limb curving outward and cutting the posterior 

 margin of the head at about one-half the distance from the dorsal 

 furrow to the lateral margin. Eye-lobes strongly and abruptly 

 elevated from the dorsal furrow, their summits being nearly 

 as high as the glabella. Fixed cheeks broad, the postero- 

 lateral angles produced into genal spines' whose entire length 

 cannot be determined in the type specimen. Eyes rather large 

 and very prominent, their surface describing nearly a semi- 

 circle. Thorax and pygidium unknown. 



The dimensions of the type specimen are: extreme width 

 between the extremities of the genal spines 18 mm., length along 

 median line 6 mm., width of glabella 5 mm. 



Remarks. This species differs from all other members of 

 the genus Proetus in its strongly convex and protuberant gla- 

 bella. In some respects its characters are as near those of the 

 genus Cyphaspis as Proetus, but the postero-lateral lobes of the 

 glabella are less prominent than in that genus and there is a 

 slight indication of a pair of lateral glabellar furrows in front of 

 the posterior pair, which are never present in Cyphaspis. It is 

 quite possible that the species should be considered as the type 

 of an undescribed genus. 



The species is named in honor of Mr. J. H. Handwerk of 

 Joliet, who collected the specimen used as the type. 



Locality. Chicago Drainage Canal near Lemont. 



Genus 5. CYPHASPIS Burm., 1843. 



Entire body sub-elliptical in outline. Cephalon semi- 

 circular with a thickened marginal border which is produced 

 posteriorly into genal spines. Glabella ovoid, strongly convex, 

 with lateral furrows obsolete except the posterior pair which 

 are deep and extend obliquely backward, connecting with the 



