DESCRIPTION OP GENERA AND SPECIES. 103 



Cheeks convex and sloping from the center toward the narrow, sharp dorsal 

 furrow about the glabella and to the furrow within the border of the cephalon. A 

 very narrow ridge extends just back of the antero-lateral angles of the glabella 

 outward so as to disappear in the furrow within the outer border. 



Glabella very narrow in front, gradually widening toward the base, and, from 

 the slight indication in the specimen, continued backward in an occipital spine; 

 it is marked by two transverse lightly impressed furrows, and what may be a faintly 

 impressed occipital furrow. 



This species shows characters that occur in two described forms: the border 

 of the head and the occipital spine are much like those of M. connexus Walcott; 

 the transverse furrows of the glabella recall those of some specimens of M . speciosus 

 Ford [1873, p. 137, figs. 2a-b]. Its occurrence in the Cambrian rocks of China 

 is most interesting. 



Formation and Locality. Middle Cambrian: (032) A fine-grained bluish- 

 black limestone bowlder believed to have come from the lower part of the Ki-sin- 

 ling limestone [Blackwelder, 19071:, p. 272]; collected in river drift i mile (1.6 km.) 

 south of Chon-p'ing-hien, on the Nan-kiang River, southern Shen-si, China. 



Collected by Bailey Willis and Eliot Blackwelder. 



Genus REDLICHIA Cossmann. 



Hoeferia REDLICH, 1901, Mem. Geol. Survey India, new. ser., vol. I, p. 2. (Genus characterized and 



discussed.) 



Not Hoeferia BITTNER, 1895. 

 Redlichia COSSMANN, 1902, Revue Critique Paleozoologie, Sixieme Ann., p. 52. (Replaces Hoeferia 



Redlich by Redlichia.) 

 Redlichia WALCOTT, 1905, Proc. U.S.Nat. Mus., vol.xxix, p. 24. (Genus described and discussed as 



below.) 



Original description (by Doctor Redlich). "The cephalic shield is almost 

 semicircular, slightly elevated, possesses movable cheeks and two long cheek spines. 

 The glabella is cylindrical, slightly contracted toward the middle, provided on 

 each side with four lateral furrows. The palpebral lobes, which surround the glabella 

 in one continuous curve, are completely separate from it and not confluent as in 

 Olenellus. The facial sutures are well developed in all the specimens, and, in con- 

 sequence of this, free cheeks are present. 



"The suture begins in the first quarter of the external margin (reckoned from 

 the glabella), extends along the eyes, and toward the posterior margin is again 

 directed outward. The fixed cheeks are very narrow, whilst the free cheeks, which 

 are provided with long cheek-spines, are almost double the width. 



"Of the thorax only isolated segments are preserved. The axial part is elevated ; 

 the pleurae are grooved (' plevrcs a sillon of Barrande), and end in a backwardly 

 directed spine. 



"On the glabella the surface of the test shows fine backwardly directed ridges 

 which are, however, so fine that they are visible only under the lens. On the 

 thickened margin they are also present, but so much stronger that they can easily 

 be shown in the figure. The cheeks, even when highly magnified, show nothing 

 of life sort, but at most a fine punctation, which, however, is mainly due to the 

 structure of the test." 



Genotype. Redlichia noetlingi Redlich [1901, p. 3, plate i]. 



Doctor Redlich compares this form with the genera Protolenus, Paradoxides, 

 and Metadoxides, but does not note its close resemblance to Zacanthoides of the 

 Middle Cambrian fauna of Nevada. For the purpose of comparison, figures of 

 the genera Redlichia, Zacanthoides, and Protolenus are illustrated on plate 24. 



