40 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxix 



short, broad axis and the character of the pleural lobes and spinose 

 border. 



Formation and locality. — Middle Cambrian; upper portion of Chang 

 Hsia formation, in hard gray limestone; Chang Hsia, Shangtung, 

 China. 



DAMESELLA CHIONE, new species. 



Of this species there are several well-preserved central portions of 

 the head, free cheeks, and pygidia. 



The head is transversely semicircular, moderately convex. Glabella 

 convex, truncato-conical, rounded in front; the length is slightl}^ 

 greater than the width at the base; a posterior pair of glabellar fur- 

 rows extends inward and obliquely backward a short distance, so as to 

 outline a small, oval, slightly convex lobe at the postero-lateral angles, 

 a second pair of ver\^ slightly impressed short glabellar furrows occurs 

 about one-half way between the posterior furrows and the front; 

 occipital furrow narrow, transverse, clearl}^ defined; occipital ring 

 narrow at the sides, increasing in width toward the center, slightly 

 convex and a little elevated at the back; dorsal furrow narrow and 

 distinct. 



Fixed cheeks about one-half the width of the glabella at the base 

 and moderately convex; they round up from the dorsal furrow and 

 are nearly flat out to the palpebral lobe, back of the line of which 

 they slope gently to the furrow of the postero-lateral limb and in 

 front more abruptly to the furrow Avithin the front margin; palpebral 

 lobe a little more than one-third the length of the head, narrow, dis- 

 tinct, but not rising above the general level of the fixed cheek; ocular 

 ridge indicated only by a very narrow, smooth line between the ante- 

 rior end of the palpebral lobe and the dorsal furrow; postero-lateral 

 limb narrow, and extending out a considerable distance to a rather 

 blunt, rounded end; front margin of the head badly preserved; it 

 appears to have been short, rounded, and separated from the glabella 

 and fixed cheeks by a narrow furrow. 



Free cheeks subtriangular in outline, with a distinct, narrow, slightl}?^ 

 elevated border and a sharp postero-lateral spine; from the base of the 

 spine an inner flattened border originates and narrows to a point below 

 the front of the eye lobe; it is defined by a narrow furrow within the 

 sharp rim and the furrow between it and the central portion of the 

 cheek; it is marked bj^ granules in the same manner as the body of 

 the cheek; the narrowing and disappearance of the flat border, leaving 

 only the narrow rim at the facial suture, indicates that the border in 

 front of the fixed cheeks of the glabella was very narrow; body of the 

 cheek moderately convex, rounding up from the furrow at its base to 

 the base of the strong eye lobe; the facial suture extends with a slightly 

 sigmoid curve from the posterior base of the eye lobe outward and 

 backward to the furrow within the rather broad posterior margin of 



