206 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 64 



CREPICEPHALUS COOSENSIS, new species 

 Plate 32, figs. 3, za-f 



This fine species occurs with a somewhat earher fauna than that 

 of C. iowensis and other species referred to Crcpicephaliis with the 

 exception of C. liliana and C. augusta (pi. 29). It belongs with the 

 C. ioivensis group of species and differs from them by its broad 

 frontal limb and border and strongly marked pygidium. The thorax 

 has 12 segments and the axial lobe of the pygidium five rings and a 

 terminal section. 



The large dorsal shield has a length of 6.5 cm. exclusive of the 

 spine of the pygidium. Fragments of the cranidium indicate that 

 a few individuals attained a length of about 7.5 cm. 



Outer surface minutely granular and apparently minutely punc- 

 tate. Fine irregular venation lines radiate from in front of the 

 glabella across the frontal limb to the edge of the border. 



All the known specimens of this species occur on the exterior of, 

 or in siliceous nodules that weather out of, a dark argillaceous shale 

 of the Conasauga formation. The associated fauna is a large one, 

 and includes: Laotira camhria Walcott, Brooksella alternata Wal- 

 cott, Micromitra alabamaensis (Walcott), Lingulella hayesi (Wal- 

 cott), Acrothele bellula Walcott, Acrotreta kutorgai Walcott, Pty- 

 choparia, several species, Anomocare, several species, and Olenoides 

 curticei Walcott. 



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 part of the Conasauga 

 formation; east of Center, near Blaine, Coosa Valley, Cherokee 

 County, Alabama. 



CREPICEPHALUS CORIA, new species 



Plate 2:2,, figs. 3- 3a-,? 

 Crepicephalus texanus Walcott, 1908, Smithsonian Misc. Coll., Vol. 53, 

 p. 178. (Name listed in fauna ib and ic of section.) 



This species is much like C. texanus (pi. 30). It differs in having 

 14 instead of 12 thoracic segments and a uniformly sized and dis- 

 tributed granulation on the exterior surface of the test. Test 

 probably punctate, as minute pits occur between the surface granules. 



The largest cranidium has a length of 3.5 cm. 



The variation in the width of the frontal border is similar to that 

 of C. texanus, and the glabella is very much alike in the two forms. 

 Crepicephalus coria is the representative in western Utah of C. 

 texanus. 



