l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 97 



CHANCIA EVAX Walcott 



Plate 5, figs. 18, 19 



CJiancia cvax Walcott, Smithsonian Misc. Coll., vol. 75, no. 3, p. 81, pi. 17, 

 fig. 27, 1925. 



Localities 55c and 55e. 



H olotypc .-—U .S.'^ M. no. 70275. 



CHANCIA ANGUSTA, n. sp. 



Plate 5, figs. 13, 14 



This species differs from C. chdotnc chiefly in that the cranidium 

 is narrower, and that the surface of the head is more finely grannlose. 

 C. angusta is characterized by a glabella which tapers at the usual 

 rate and attains slightly more than half the cranidial length. Three 

 pairs of furrows are faintly defined, the rear pair being directed 

 sharply backward. Eyelines are well developed on the under side of 

 test. Eyes moderately elevated. 



Exfoliated specimens have all furrows accentuated, and the doublure 

 impression modifies the appearance of the unfurrowed brim. 



Locality 55c. 



Holotypc and paratypes. — U.S.N.M. no. 96523. 



ALOKISTOCARELLA Resser, 1938 

 ALOKISTOCARELLA SPENCEI, n. sp. 



Plate 3, fig. ID 



This species is represented by several cranidia, all of which are, 

 unfortunately, almost entirely exfoliated. This, of course, accentuates 

 all furrows and ridges. A. spencei is characterized by a truncate 

 glabella of normal size and an upturned narrow rim. The width 

 of the fixigene at the eye is about equal to that of the glabella at the 

 same point, which makes the cranidium wide. 



Locality 55c. 



Holotype. — U.S.N.M. no. 96509. 



ELRATHIA Walcott, 1924 

 ELRATHIA SPENCEI, n. sp. 



Plate 6, figs. 15-17 



This species has 17 thoracic segments. The cranidium is wide, the 

 glabella occupying about three- fourths its length. The small pygidium 

 is characteristic of the genus, and it has an indented rear margin. 



Locality 55c. 



Holotype and paratypes. — U.S.N.M. no. 96540. 



