DESCRIPTION OF GENERA AND SPECIES. 151 



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 extraordinarily strong spine, which 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 gla- 

 bella 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 Microdiscus; dorsal furrow deep, and strongly 

 developed on the sides and in front of the glabella. 



Fixed cheeks about 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 lobes small; a narrow, clearly defined palpebral ridge extends obliquely 

 backward across the fixed cheek from the antero-lateral angle of the glabella. 



Surface minutely granular under a very strong lens. The type specimen has 

 a length of 5 mm., exclusive of the combined occipital ring and spine. 



This species is most nearly related to /. melie [p. 153] and I. ? acalle [p. 150]. 

 It differs from them in the form of the convex fixed cheeks and frontal limb, the pres- 

 ence of palpebral ridges, the extraordinarily strong occipital spine, and in having a 

 proportionately shorter glabella. 



Formation and Locality. Middle Cambrian: (C75) Limestone near the base 

 of the Ki-chou formation [Willis and Blackwelder, 1907, p. 143], 4.5 miles (7.2 km.) 

 south of Wu-t'ai-hien, Shan-si, China. 



Collected by Eliot Blackwelder. 



Inouyia capax (Walcott). 

 Plate 14, Figures n, na. 



Agraulos (?) capax WALCOTT, 1906, Proc. U. S. Nat. Mus., vol. xxx, p. 580. (Species described and 

 discussed essentially as below.) 



As indicated by the central portions of the cephalon exclusive of the free cheeks, 

 the cephalon of this species is semicircular in outline, and moderately convex. The 

 glabella narrows slightly from the base to its rounded front, which springs from the 

 point where the palpebral ridges pass into the dorsal furrow; the surface of the 

 glabella is marked by three pairs of short, slightly impressed glabellar furrows that 

 divide the glabella into a posterior subtriangular lobe, two narrow lobes, and a 

 larger front terminal lobe; occipital furrow rounded, not very deep, and slightly 

 wider at the sides than in the center; occipital ring narrow at the sides, widening 

 toward the center, where there is a low, small node near the posterior margin ; dorsal 

 furrow narrow, deep in front, and shallow at the sides of the glabella. 



Fixed cheeks broad, rising gently from the dorsal furrow to the palpebral lobes; 

 they slope gradually to the posterior furrow, and, in front of the palpebral ridges, 

 rather rapidly to the broad furrow defining the frontal limb ; palpebral lobe small, 

 narrow, and passing in front into a narrow palpebral ridge, which crosses the fixed 

 cheek to the antero-lateral angle of the glabella; frontal limb separated from the 

 glabella by a narrow, deep furrow, which widens out on each side; the limb is 

 strongly convex immediately in front of the glabella, where it rises on some examples 

 into a transverse boss; in other specimens it is not much higher than the general 

 elevation of the glabella. 



vSurface marked by shallow, irregular, minute pits when examined with a strong 

 lens. The cephalon of the largest specimen in the collection has a length of 7 mm., 

 with a width of 12 mm. at the palpebral lobes. 



