DESCRIPTION OF GENERA AND SPECIES. 155 



Formation and Locality. Middle Cambrian: (028) Thin-bedded oolitic lime- 

 stone at the base of the Ch'ang-hia limestone [Blackwelder, 19070, p. 32 (first list 

 of fossils), and fig. 6 (bed 20), p. 25], just above the shales in the face of the cliff 

 i mile (1.6 km.) east-southeast of Ch'ang-hia, Shan-tung, China. 



Collected by Eliot Blackwelder. 



Inouyia titiana (Walcott). 

 Plate 14, Figure 9. 



Ptychoparia titiana WALCOTT, 1905, Proc.U.S. Nat. Mus., vol. xxix, p.8i. (Species described essen- 

 tially as below.) 



Cephalon quadrilateral in outline, exclusive of the free cheeks, moderately 

 convex. Glabella gently convex; broadest at the base, narrowing midway, and 

 with the sides nearly parallel from the center to the broadly rounded front; gla- 

 bellar furrows shallow; there are three on each side that penetrate to the central 

 third of the glabella and divide it into two small central lobes, a short terminal lobe, 

 and a posterior lobe that is broad at the sides and narrow toward the central third ; 

 occipital furrow narrow ; occipital ring rounded at the sides and gradually thickening 

 toward the center to form the base of a rather strong spine of unknown length; 

 dorsal furrow shallow, but clearly defined. 



Fixed cheeks of medium width, about two-thirds the width of the glabella; 

 palpebral lobes central and about one-third the length from the posterior to the 

 frontal margins of the cephalon; palpebral ridge narrow, clearly defined; it starts 

 near the front line of the glabella and extends obliquely backward and merges into 

 the rim of the palpebral lobe ; postero-lateral limbs short and marked by a broad, 

 shallow furrow; frontal limb convex, prominent, about as long as the fixed cheeks 

 at the eye-lobes; at the front it slopes into the rounded groove back of the narrow, 

 slightly flattened frontal rim. 



Surface slightly roughened over the central portions; on the frontal limb a 

 network of fine, irregular, raised lines extends from the dorsal furrow and palpebral 

 ridges to the furrow inside the frontal rim. 



This species is associated with Anomocarella thraso [p. 208]. Its strong frontal 

 limb and occipital spine distinguish it from other species. 



Formation and Locality. Middle Cambrian : (0 7) Lower limestone member of 

 the Kiu-lung group [Blackwelder, 19070, pp. 37 and 39 (last list of fossils), and 

 fig. 8a (bed 33), p. 29], 2.2 miles (3.5 km.) southwest of Yen-chuang, Sin-t'ai district, 

 Shan-tung, and (028) thin-bedded oolitic limestone at the base of the Ch'ang-hia 

 limestone [idem, p. 32 (first list of fossils), and fig. 6 (bed 20), p. 25], just above the 

 shales in the face of the cliff i mile (i. 6km.) east-southeast of Ch'ang-hia, Shan-tung, 

 China. 



Collected by Eliot Blackwelder. 



Genus AGRAULOS Corda. 

 Agraulos CORDA, 1847, Prodrom einer Monographic der bohmischen Trilobiten, p. 26. 



In order that direct comparison may be made with illustrations of the type 

 species, one of the figures given by M. Joachim Barrande is reproduced [plate 15, 

 fig. i a] and a photograph of two specimens [plate 15, fig. i] from the typical locality 

 in Bohemia. As we have only the cranidium of the various species from China 

 referred to Agraulos, the generic identification is made subject to revision on the 

 discovery of entire specimens. There will also be differences of opinion as to the 

 species included tentatively under the genus, as there is considerable variation 

 among the cranidia of A. uitida [plate 15, fig. 2], A. obscura [plate 15, fig. 4], A. itta 

 [plate 15, fig. 7], and A. vicina [plate 15, fig. 8]. 



