576 PJiOCEEDIXGS OF THE NATIONAL MUSEUM. y<.i.. xxx. 



Genus AGRAULOS Corda. 

 AGRAULOS ARMATUS, new species. 



This .species is represented by a tinely preserved specimeu of the 

 central portions of the head, exclusive of the free cheeks. The glabella 

 is stronglv convex, with the sides slig-htl}^ converging- toward the 

 rounded front; it is marked b}' three pairs of short, obscure glabellar 

 furrows close to the dorsal furrow; the occipital furrow is indicated 

 by a short, scarcely discernible depression toward the side of the union 

 of the glabella and occipital ring; occipital ring a little narrower than 

 the glabella and extended backward into an extraordinarih' strong 

 spine, that is nearly as broad as the glabella to a point corresponding 

 in length with the glabella; the posterior termination of the spine is 

 not preserved; on the side view the surface of the glabella extends 

 backward continuously with that of the occipital ring and spine, on the 

 same plane; the strong backward extension of the glabella recalls some 

 of the large occipital spines in some species of J/icrodiscufi^- dorsal 

 furrow deep, and strongly developed on the sides and in front of the 

 glabella. 



Fixed cheeks aljout as wide as the glabella, strongly convex, and 

 merging into a convex frontal limb that is wider and more convex than 

 the fixed cheeks; palpebral lo})es small; a narrow, clearly defined 

 ocular ridge extends obliquely backward across the fixed cheek from 

 the antero-lateral angle of the glabella. 



Surface minuteh^ granular under a very strong lens. The type 

 specimen has a length of 5 mm., exclusive of the combined occipital 

 ring and spine. 



Ohservation.s. — This species is most nearl}- related to ^1. {.'*) hulie 

 (p. 581) and ^1. acaUe Walcott." It differs from them in the form of 

 the convex fixed cheeks and frontal limb, the presence of ocular ridges, 

 the extraordinarily strong occipital spine, and in having a proportion- 

 ately shorter glabella. 



Formation and locality. — Middle Cambrian, in l)rownish gray, oolitic 

 limestone, 10 feet above red shales of supposed Man-t'o formation age; 

 4.5 miles south of Wu-t'ai-hien, 8han-si, China. 



Collected by Eliot Blackwelder, 



AGRAULOS NITIDA, new species. 



This species is represented by the central portions of the head, 

 exclusive of the free cheeks; the front within the facial sutures is 

 strongl}' rounded, indicating a semicircular outline for the head, which 

 was moderateh' convex. Glabella truncato-conical, moderately con- 

 vex, and not very clearly defined from the fixed cheeks and frontal 

 limb; there are no traces of glabellar furrows; occipital furrow repre- 



«Proc. U. S. Nat. Mus., XXIX, 1905, p. 43. 



