394 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 64 



it seems quite probable that it belongs with the cranidium to which 

 it is referred. 



Surface of both cranidium and pygidium finely granulated. The 

 largest cranidium has a length of 21 mm. and associated pygidium 

 of 19 mm. With the thorax of proportional length the dorsal 

 shield would have a length of 60 mm., which would make it the 

 largest species of the subgenus Blainia. 



Formation and locality. — Middle Cambrian: (gox) Conasauga 

 formation ; in and attached to the outer surface of siliceous nodules 

 in a dark argillaceous shale of the lower Conasauga formation ; 3 

 miles (4.8 km.) east of Center, near Blaine, Coosa Valley, Cherokee 

 County, Alabama. 



ASAPHISCUS (BLAINIA) GLABRA, new species 

 Plate 63, figs. I, la-e 



This species is known only by the cranidium and associated 

 pygidium and fragments of thoracic segments. The cranidium is 

 much like that of A. (B.) gregarius, differing only in the relative 

 widths of the frontal limb and border and slightly broader fixed 

 cheeks. The associated pygidium differs in form, width of border, 

 and length of axial lobe. 



Exterior surface finely granulated. Judging from the separate 

 parts, the dorsal shield probably equalled if not exceeded the size 

 of the dorsal shield of A. (B.) gregarius and A. (B.) paula. 



The fossils associated with A. (B.) glabra are Hyolithes, Ptycho- 

 paria sp., and a fine species of an undetermined Olenoides. 



Formation and locality. — Middle Cambrian: (107X) Conasauga 

 formation ; compact oolitic limestone in boulder on hillside, Bull 

 Run Knobs near creek, west of Copper Ridge, 2 miles (3.2 km.) 

 south of Heiskell, Knox County, and ii miles (17.7 km.) north- 

 west of Knoxville, Tennessee. 



ASAPHISCUS (BLAINIA) GREGARIUS, new species 



Plate 62, figs. I, la-i 



This species is so well illustrated by the figures of plate 61 that 

 a general description is unnecessary. The cephalon has rather 

 large, free cheeks with medium size genal spines ; the glabella is 

 marked by three pairs of side furrows in the smaller specimens, as 

 shown by figure le, but in the larger they are very slightly marked; 

 the nine thoracic segments have narrow diagonal pleural furrows and 

 a rather abrupt termination of the ends of the segments. The pygi- 



