32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



furrows indicating seven anchylosed segments ; the posterior fur- 

 rows are nearly parallel to the sides of the axial lobe ; the furrows 

 all terminate on the inner portion of the outer border, the pleural 

 furrows with a slight, elongate pit just within the border. 



Surface with variously arranged, irregular, raised lines or narrow, 

 sharp ridges ; on the glabella they are very slender and arranged in 

 a somewhat concentric manner, although they are broken and 

 irregular ; on the fixed and free cheeks the raised lines are much 

 stronger, irregular, and more or less anastomosing; on the thoracic 

 segments the short, irregular raised lines cross the segments of the 

 axis on each side between the central node and the dorsal furrow, 

 and on the pleurae they extend obliquely across the raised spaces 

 between the furrows ; the pygidium has about the same markings at 

 the thorax except on the flattened border, Avhere the short, elevated, 

 irregular lines extend across the border. 



Dimensions. — There are two small, nearly entire dorsal shields. 

 One, having a length of 24 mm. exclusive of the posterior spines 

 of the pygidium, has the following dimensions : 



Cephalon : mm. 



Length 9-5 



Width at posterior margin 11. 5 



Thorax ; 



Length 8.0 



Width at first segment 14 . 



Pygidium : 



Length 7.5 



Width at anterior margin 10. o 



A large cranidium, 52 mm. in length, has the following dimen- 

 sions : 



Glabella : mm. 



Length 42 . o 



Width at posterior margin 88.0 



Width at occipital furrow 26.0 



Width just in front of ocular ridge 34.0 



Palpebral rim, length 7.0 



A large pygidium, 58 mm. in length, has the following dimen- 

 sions : 



mm. 



Width at anterior margin 76.0 



Axial lobe, length 52 . 



Axial lobe, width at anterior margin 19.0 



Axial lobe, width at anterior segment 19.0 



Axial lobe, width at posterior section 10. 



Pleural lobe, width at anterior margin 28.5 



