:f h: izr l l o if o id j^ 



LIMNADIAD.'E. 



ESTHERIA, RttppELL. 1857. 



ESTHERIA PULEX. 

 PLATE XXXV, FIGS. 10,11. 



EsOu Ci irke. Amer. Jour. Science, Third Series, vol. xxiii. p. 476. plate 0, fig-. 4. 1882, 



Estheria pulex, Packard. Monogr. North Amer. Phyllopod Crust,, p. 355; Twelfth Ann. Rept. U. S. Geol. 



Surv. 1883. 

 Estheria pulex, Ethehidqe, Woodward and Jones. Fifth Rept, Committee on Fossil Phyllopoda of the 



Palseozoic Rocks, p. 10. 1887. 



Carapace minute ; outline sub-circular; beaks slightly anterior, prominent and 

 somewhat incurved. Surface evenly and strongly convex, the most elevated 

 point being the center of the valve. 



Hinge-line short and somewhat obscured by the anterior and posterior 

 slope from the beak. The surface bears six or eight concentric ridges, 

 which arc broad and flattened above and separated by narrow furrows. 

 flic test is tenuous, and the very narrow, impressed interstitial furrows do 

 not show any trace of the fine sculpturing often observed in other species 

 of this genus. 



01 this species six individuals have been observed, the average dimensions 



of which are \ mm. in length and § mm. in width. Five of these occur 



i her upon a small fragment of shale about 15 mm. square, upon which 



twenty individuals of Entomis, Betjrichia and Leperditia are crowded. The 



much, are from a thin layer in the Hamilton shales, which is extremely 



