70 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxix. 



defined at the sides and somewhat less so in front of the glabella; a 

 shallow pit occurs opposite the antero-lateral angle of the glabella. 



Fixed cheeks narrow and convex; they slope, gently backward and 

 merge into the postero-lateral limb, and forward in advance of the 

 palpebral lobe slope rapidly downward to the rounded frontal limb; 

 palpebral lobes broken away, but from the form of the fixed cheek 

 they appear to have been about one-third the length of the head; 

 postero-lateral limbs about as long as the width of the glabella, and 

 marked by a broad, strong furrow within the narrow postero-lateral 

 margin; frontal lobe and rim united to form a rounded, downward 

 curving frontal border of the head, separated from the glabella by the 

 strong dorsal furrow. 



Surface marked by numetoas irregularly placed pustules except in 

 the furrows of the glabella, dorsal furrow, and furrow on the postero- 

 lateral limbs. The type and only specimen of the head in the collec- 

 tion has a length of 17 mm., with the glabella 10 mm. in width and 

 11 mm. long. 



In size and general appearance this species ma}^ be compared with 

 -P. ceto. It differs in its strongly pustulose surface, less convex 

 glabella and fixed cheeks, and in the form of the frontal border of the 

 head. At first sight it is apparentlv identical with P. calyce^ but it 

 differs in the form of the transverse furrows and the frontal lolie of 

 the glabella, which in F. calyce is globose, like that of P. ceto. 



Foruuitlon and locality. — Upper Caml)rian, upper portion of the 

 Chao Mi Tien formation; 2.7 miles southwest of Yen Chuang, Hsin 

 Tai, Shangtung, China. 



Collected by Eliot Blackwelder, of the Carnegie Institution of 

 Washington Expedition to China. 



PTYCHASPIS CADMUS, new species. 



This species is represented by more or less fragmentary specimens 

 of the central portions of the head, exclusive of the free cheeks. 

 Glabella moderately convex at the back and strongly convex at the 

 front, marked by a posterior transverse furrow that arches slightly 

 backward, cutting off' a narrow lobe between it and the dorsal furrow; 

 anterior lobe a little longer than wide, and marked by a pair of short, 

 narrow furrows opposite the anterior end of the palpebral lobe; the 

 anterior lobe is convex, but not globose; occipital furrow strong; 

 occipital ring unknown; dorsal furrow strong and rather deep. 



Fixed cheeks ver}^ narrow and diappearing into the dorsal fui'row 

 in front of the palpebral lobe; posteriorly they slope downward as an 

 irregular ridge to the postero-lateral limb; palpebral lobes about one- 

 fourth the length of the head and marked by a deep groove within the 

 narrow rim; frontal limb narrow and sloping outward and downward to 

 the front margin from the broad, strong, dorsal furrow; it is marked by 

 two transverse rows of large tubercles; postero-lateral limbs unknown. 



