NO. 3 CAMBRIAN AND OZARKIAN TRILOBITES 83 



DESMETIA, new genus 



There is barely sufficient material to allow a description of the 

 genus, but because it is unusual in several respects, it is included in 

 this preliminary work. 



The glabella is rounded with minute recurved glabellar furrows. 

 Fixed cheeks and frontal limb wide and convex. Eyes small and far 

 forw^ard. 



Observations. — At first sight it seems as if Desmetia and Ray- 

 mondina Clark ^ are synonymous, and the insufficiency of material 

 will not now allow a solving of this question. Clark's figure, according 

 to imperfect casts, is incorrect in the unusual rearward extension of 

 the postero-lateral limbs. The forward turning of the occipital furrow 

 on the fixed cheeks argues strongly for the Proparian nature of Ray- 

 mondina and the straight course of the same suture in Desmetia would 

 seem to indicate a difference. Desmetia also seems to lack a frontal 

 border. 



Genotype.— Ptychoparia ? annectans Walcott. 



Range. — Ozarkian : Nevada. 



- DESMETIA ANNECTANS (Walcott) 



Plate IS, figs. 24, 25 



Ptychoparia f annectans Walcott, 1884, Monogr. U. S. Geol Surv., Vol. 8, 

 p. 94, pi. 12, fig. 18. (Described and illustrated.) 



See original description. 



Formation and locality. — ? Ozarkian: (201) Goodwin formation. 

 East slope of the ridge east of Hamburg ridge, Eureka District. 

 Nevada. 



Genus DOKIMOCEPHALUS Walcott 



Dokhnocephalus Walcott, 1924, Smithsonian Misc. Coll., Vol. 75, No. 2, p. 55. 



Observations. — This genus is characterized by the great extension 

 of the frontal border and large convex glabella. It may be compared 

 with Burnetia (pi. 17, figs, 1-3) and Elkia (pi. 18, figs. 1-3). 



Proampyx Freeh, based on Anomocare acnminatus Angelin, and 

 to which the genotype had been referred, is too uncertain to be used. 

 It has a nasute extension of the frontal border but dififers in glabella, 

 occipital ring, and frontal limb. 



Two species have been referred to the new genus, D. pernasutus 

 (Walcott) and D. gregori, new species. Free cheeks similar to the 

 one assigned to D. pernasutus are present in collections from several 



'■ Clark, Bull. American Pal, Ithaca, N. Y.. 1924, Vol. 10, No. 41, p. 35, pi. 4, 

 fig. 8. 



