VOL. XIII, 



1890. 



] PROCEEDINGS OF THE NATIONxVL MUSEUM. 273 



i^in obliquely backward about oue-tburtli the distauce across. Occip- 

 ital furrow, narrow and arching forward at the ceuter; occipital seg- 

 ment of medium width, arching forward at the center where a small, 

 sharp node occurs; dorsal furrows strongly detined all about the gla- 

 bella. 



Fixed cheeks narrow and merging i)osteriorly into the rather long 

 posterolateral limb, and anteriorly into the broad slightly convex fron- 

 tal rim ; palpebral lobes of medium size. The only division between 

 the frontal limb and the nearly flat margin is a series of slight intlenta- 

 tions ; a similar line is also seen on the under side; in some specimens, 

 however, this line of indentations is not shown and the frontal limb and 

 rim merge together; in some others a slight transverse groove indicates 

 the line of separation. The free cheeks are i)rolouged posteriorly into 

 a long slender spine and have a faintly defined marginal rim. 



The associated pygidium is transverse, convex, and strongly trilobed 

 by the prominent, convex median lobe; marginal border narrow and 

 nearly flat; median lobe divided by three transverse grooves into three 

 annulations and a posterior more elongate termination ; lateral lobes 

 somewhat depressed and marked by three shallow furrows that extend 

 from the median axis to the flattened margin. 



Test rather thick over the frontal lobe and margin and strong on 

 other parts. . Surface apparently smooth or finely striate ; tbii5 character 

 is not well shown. 



Of described si)ecies this is most nearly allied to Ptyehojyaria eryon 

 Hall.* 



Formation and locality. — Upper Cambrian limestone. Packsaddle 

 Mountain, Llano County, Texas. Collector, C. D. W., 1884, 



Nat. Mus. Cat. Invert. Foss,, 23857. 



Ptychoparia ? metra sp. uov. 

 Plate XXI, Figure 7. 



Glabella conical strongly convex; occipital furrow, broad, shallow, 

 and rounded; occipital segment of medium width and convexity; dor- 

 sal furrows deep on the sides and strongly defined in front of the gla- 

 bella. Fixed cheeks only a line between the dorsal furrow and i)alpe- 

 bral lobes; the latter are relatively large and grooved by a broad furrow 

 parallel to the margin ; anteriorly the fixed cheek widens out to form a 

 small subtriangular area before reaching the frontal furrow ; its pos- 

 terior extension is unknown ; frontal limb very short and descending 

 down to the broad, concave frontal furrow that curves up to meet the 

 short edge of the strong thick frontal margin. Surface a little rough in 

 the cast ; this may indicate a pustulose surface on the outer test. 



This species is apparently congeneric with P. iirania and the generic 

 reference is provisional. 



* Sixteenth Ami. Rep. State Cab. Nat. Hist., 18G3, p. 1.57, pi. vii, figs. 10-lG : pi. viii, 

 figs. 16, ;u. >.!-.& 



Proc. N. M. 90 18 



