NO. 1415. CAMBRIA IV FAUNAS OF CHINA— WALCOTT. 37 



defined transverse furrows, that arch slightly forward, into four 

 modeniteiy convex rings and a somewhat elevated terminal portion 

 which has the appearance of a thickened ring, with a strong node on 

 each side of the center and a slightly defined furrow on its front slope; 

 the terminal ring slopes rapidly downward to the border; lateral 

 lobes broad, slightly convex, and marked by a narrow anterior ring, 

 which joins the thorax, and four strong, rather broad furrows that 

 separate three rings and a broad, obscure terminal ring; two obscure 

 ridges run down the posterior slope of the central axis from the two 

 nodes upon the posterior end of the central axis and terminate in 

 spines on the l)order; each of the rings of the pleural lobe, including 

 the anterior border, terminates in a long, slender spine, that of the 

 anterior border being much longer than the others; this arrangement 

 gives five spines on each side of the axis and two spines back of the 

 axis; the border is rounded and much interrupted b}" the strong spines 

 extending out from it. 



Surface of the crust minutely punctate under a strong lens, and 

 marked by strong pustules, more or less irregularly arranged on the 

 surface, except in the furrows; on the segments of the thorax the pus- 

 tules are arranged on the front and back margins of the pleura and 

 on the higher portions of the rings on the axis; on the p5^gidium the 

 pustules occur on the elevated rings and somewhat irregularly on 

 the pleural lobes, but not on the spines. On some portions of the 

 surface, under a very strong lens, there appears to be an irregular, 

 inosculating, elevated series of lines or stria? interrupting the surface, 

 leaving minute depressions or punctte between them. 



The portion of the thorax preserving twelve segments has a length 

 of 50 mm., with a width at the anterior end of the axis of 16 mm., and 

 on the pleural lobes of 24 mm.; the head of this specimen has a length 

 of 26 mm. and a width of CA mm., exclusive of the postero-lateral 

 spines. 



Observations. — The pygidium of this species is not unlike that of 

 Olenoides hhlanci Bergeron, « from China, but it difi'ers in the more 

 depressed axis and in the character of the spines on the border. This 

 conclusion is given after an examination of the figures of M. Bergeron 

 and a comparison of specimens which have been identified as Olenoides 

 lehlanci from the Ku San shale formation, 2.5 miles southwest of Yen 

 Chuang, Hsin Tai, Shangtung, China, which appears to be the horizon 

 from which the various species described by M. Bergeron were 

 obtained. From Olenoides mciTcoui the pygidium of Dainesella hlack- 

 imlderi difi'ers in the same manner as from 0. leblanci. From Dory- 

 jn/ge slatskowshii Fr. Schmidt,* it differs in the character of the head 

 and the general shape of the pygidium and its spinose border. From 



«BuIl. Soc. Geol. de France, 3d ser., XXVII, 1899, p. 46. 



6 Mem. Acad. Imp. Sci. St.-Petersbourg, 8th ser., VIII, No. 10, p. 33, pi. ii, figs. 1-10. 



