42 Annals of the Carnegie Museum. 



at the gcnal angles. The anterior limb of the facial suture meets the 

 frontal margin in front of the eye. There is a narrow depressed border 

 on the front of the cranidium. 



Axial lobe of thorax one-third the total width; pleura grooved. Pygi- 

 dium short, wide, semicircular in outline. Axial lobe narrow, rathei 

 prominent, showing traces of two or three rings. Pleural lobes convex, 

 without traces of ribs. Border narrow, concave; doublure narrow, con- 

 vex. Hypostoma quadrangular, widest in front, central portion convex, 

 with a furrow and narrow border around the sides and posterior end. 

 Surface of all parts, including the hypostoma, covered with imbricating 

 striae. 



One pygidium is 9.5 mm. long and 18 mm. wide; a larger one is 14 mm. 

 long and 28 mm. wide. 



This species differs from the only other American species of the sub- 

 genus now known (Asaphellus? planus Matthew)^ in having a more promi- 

 nent axial lobe on the pygidium, and in having the median tubercle 

 between the eyes instead of back of them. The genal spines are also 

 longer and more rounded in section. 



This species is also much like Asaphellus gyracanthus, but beside the 

 difference in the course of the facial suture, the cephalon of the species 

 here described is shorter and wider, the eyes are farther apart, and the 

 axial lobe of the pygidium is much more prominent. 



Locality. — -This species is described from specimens from a layer 3,866 

 feet below the top of the Beekmantown at Bellefonte, Center County, 

 Pennyslvania. It is named for Professor George L. Collie, Dean of Beloit 

 College, who collected the specimens. Cotypes in the Carnegie Museum. 



Symphysurus convexus (Cleland). 

 Plate XIV, figures 14-16. 



Asaphus convexus Cleland, Bulletin American Paleontology, III, 1900, 128, pi 



16, fig. 4. 

 Bathyurus sp. Cleland, Ibidem, 1900, pi. 16, fig. 9. 

 Illanurus columhiana Weller, Paleontology of New Jersey, III, 1902, 133, pi. 



5, figs. 1-4. 

 Bathyurus? levis Cleland, Bulletin American Paleontology, IV, 1903, 36, pi. 2, 



figs. I, 2. 



This species was first described from a pygidium obtained by Cleland 

 in the Beekmantown at Fort Hunter, New York. Later Weller obtained 



'^Bulletin Natural History Society New Brunswick, IV, 1902, 413, pi. 18, fig. il 



