274 NEW UPPER CAMBRIAN FOSSILS WALCOTT. 



Formation and locality.— JJi^i^ev Cambrian (Potsdam Terrane). "Ta- 

 tur Hill," Biiniet County, Texas. Collector, C. D. W., 1884. 

 Nat. Mus. Cat. Invert. Foss., 23858. 



Ptychoparia pero sp. nov. 

 Plate XXI, Fig. 6. 



The portion we have of this species is closely related to P. explanata* 

 Whitfield and P. diademata^] but differs in the conformation of the 

 frontal limb, groove, and flattened margin. The specimens from Texas 

 and Wisconsin appear to be identical as far as comparisons can be made 

 between them. 



Formation and Zomi%.— Upper Cambrian (Potsdam Terrane). In a 

 limestonr' ou Morgan's Creek, Burnet County, Texas, and in a butt" or 

 brown sandstone, Trempeleait, Wisconsin. Collectors, in Texas, C. D. 

 W.7 in Wisconsin, Dr. Cooper Curtice. 



Nat. Mus. Cat. Invert. Foss., 23859. 



Ptychoparia suada sp. nov. 

 Plate XXI, Fig. 9. 



Glabella short, convex, truucato-conical ; occipital furrow strongly 

 detineil ; occipital ring convex, of medium width at the center and nar- 

 row at the sides; surface smooth; dorsal furrows deep on the sides 

 and well marked in front of the glabella. Fixed cheeks narrow, con- 

 vex, palpebral lobes relatively large and differentiated from the cheek 

 by a shallow furrow ; ocular ridge narrow; frontal limb rather long, 

 abruptly curved downward to the narrow frontal rim. 



The form of the head and glabella recalls P. minor of the lower por- 

 tion of the Upper Cambrian sandstones of Wisconsin, but the absence 

 of a nuchal spine and glabella furrows serves to distinguish them. 



Formation and localiti/. — Upper Cambrian (Potsdam Terrane). In 

 limestones on Morgan's Creek, Burnet County, Texas. Collector, C. 

 D. VV. 



Nat. Mus. Cat. Invert. Foss., 23860. 



Ptychoparia ? iirania sp. nov. 



Plate XXI, Figs. 10 and 11. 



Glabella tumid, truncato-conical in outline; surface marked by two 

 l)airs of furrows; the posterior pair extend obliquely backward so as 

 to mark olf a triangular lobe on each side. Anterior pair shorter and 

 more transverse in their direction; occipital furrow rounded; occipital 

 ling narrow; dorsal furrow strongly defined. Fixed cheeks narrow, 

 posterior extension unknown ; anteriorly they merge into the very short 



* Geol. Wis., vol. iv, 18H2, p. 181, pi. 1, figs. 27,28. 



t Sixteenth Rep. N. Y., State Cah. Nat. Hist., 1863, p. 167, pi. vii, figs. 36-39; pi, 

 viii, figs. 1H,21. 



