NO. 1415. CAMBRIAN FA UNAS OF CHINA— WALCOTT. 35 



ments and is without a median spine; from what is known of the head 

 of Olenoldes it is probably the same as tliat of J)oryj>y<jf. 



Genotype. — Daiaesella hlackioelderi Walcott. 



The species referred to the genus are: Damesella lAackwelderi Wal- 

 cott, I). heUagranuIata Walcott, D. hrevicaudata Walcott, D. chione 

 Walcott, D. sinensis BeYgeron = DiGelloceph(dus f sinensis Bergeron. 



The genus Dinesus Etheridge, jr.," appears to be more nearl}^ 

 related to Dory2>y<je Dames than to Damesella or DorypygeJla Wal- 

 cott. Its marked characteristics are: the elongate oval glabella, with 

 the small, distinct antero-lateral and postero-lateral lobes; the small 

 palpebral lobes; and the large pygidium with a spinose border. Only 

 one species is known — Dinesus Ida Etheridge, jr. 



Under the definition of Proparia, Dr. C. E. Beecher gives as an 

 ordinal character "Free cheeks not bearing the genal angles,"* and 

 under Opisthoparia he said "Free cheeks generally separate, always 

 bearing the genal angles."'' In Damesella, the facial suture cuts the 

 postero-lateral margin outside of the genal angle, so as to leave the 

 genal angle on the fixed cheeks and at the same time the spine corre- 

 sponding to the genal spine in other genera of the order Proparia on 

 the free cheek. In other characters Damesella belongs with the Pro- 

 paria, and 1 think that the definitions of the orders Proparia and Opis- 

 thoparia need to be modified in relation to the exception made by 

 Damesella in the position of the genal angle on the fixed cheek. 



DAMESELLA BLACKWELDERI, new species. 



General form ovate, moderately convex; distinctly trilobed, the 

 central axis rather strongl}' convex, and the pleural lobes more or less 

 flattened. 



Head transversely semicircular; frontal margin rounded and narrow 

 in young individuals, becoming broader and more flattened with 

 increase in size; it continues around the sides and the postero-lateral 

 angle to unite with the narrowing posterior margin. A postero- 

 lateral spine projects backward and slightly outward from a point on 

 the margin a little in advance of the postero-lateral angle. 



Glabella large, truncato-conical in outline, and marked b}^ three 

 pairs of short furrows; the posterior pair of furrows form a rounded 

 pit near the margin and continue o})liquel3^ outward as a shallow fur- 

 row to the central third of the glabella, separating a short, rounded 

 lobe on each side; the middle pair of furrows are short and very lightl}" 

 impressed; the anterior pair of furrows are indicated by a short, 

 smooth, narrow space at the anterior fourth of the glabella; occipital 

 furrow of medium width, rounded at the bottom and rather deep; it 



«Proc. Roy. Soc. Victoria, VIII, n. ser., 1896, p. 56, pi. i, figs. 1-5. 

 &Am. Jour. Sci., Ill, 1897, p. 198. 

 cidem, p. 187. 



