120 PALEONTOLOGY OF NEW YORK. 



more like those ofEumetria Verneuiliana, Hall. The hinge-plate bears two short 

 processes on its posterior edge, which extend only for a short distance into the 

 umbonal cavity ; this organ is very imperfectly known, but as far as under- 

 stood it seems to be nearer in structure to that of Hustedia than of Eumetria. 

 Acambona prima was described from the lower beds of the Burlington 

 limestone, and it is quite probably identical with the species described by 

 Professor Swallow, at an earlier date, as Retzia Osagensis, from the Choteau 

 limestone. 



Genus HUSTEDIA,* gen. nov. 



PLATE LI. 



1858. Terehratula, Makcod. Geolog-y of North America, p. 51, pi. vi, fig. 11. 



1859. Retzia, Meek and Haydbn. Proc. Acad. Nat. Sci. Philadelphia, vol. iii, second ser., .p. 27. 



1860. Retzia, McChe.sney. New Palfeozoic Fossils, p. 45. 



1866. Retzia, Geinitz. Carbon iind Dyas in Nebraska, p. 39, pi. iii, fig. 6. 



1868. Retzia, McChesnev. Trans. Chicag-o Acad. Science.s, vol. i, p. 32, }>!. i, fig-. 1. 



1872. Retzia, Meek. Hayden's U. S. Geol. Survey Nebraska, p. 181, pi. i, fig. 13 ; pi. v, fig. 7. 



1874. Eumetria, Derby. Bull. Cornell University, vol. i, p. 4, pi. viii, figs. 4, 5, 7, 8, 10 ; pi. ix, fig 3. 



1875. Terehratula, Marcod. Trans. St. Louis Acad. Sci., vol. iii, p. 252. 



1875. Retzia, White. Wheeler's Geogr. Surveys West of 100th Meridian, vol. iv, pp. 141, pi. x, fig. 7. 



1883. Eumetria, Waauex. Pala?ontologia Indica, ser. xiii, vol. iv, p. 487. 



1884. Retzia. Walcott. Monogr. U. S. Geol. Survey, vol. viii, p. 220, pi. vii, fig. 5. 



1884. Retzia, White. Thirteenth Ann. Kept. State Geologist Indiana, ji. 136, pi. xxxv, figs. 10-12. 



In external characters the shells constituting this genus are indistin- 

 guishable from those of Eumetria, except in their much coarser plication. 

 For this reason they have been classed under the latter genus by several 

 writers, though the internal structure in the two groups is curiously distinct. 

 While the complicated structure of the interior in Eumetria was not under- 

 stood such an association of the species was altogether natural. The type of this 

 new genus the Terehratula Mormoni, Marcou (= Retzia pundulifera, Shumard), — 

 a characteristic species of the upper Coal Measures in both North and South 

 America. The essential difference of this species from Eumetria vera lies in the 



* To the memory of the Honorable James William Husted, this interesting and widely distributed genus 

 of Brachiopods is dedicated. A j)atron and promoter of science, who, during a period of more than twenty 

 years, as Representative in the Assembly of the Legislature of New Yoi-k, zealously e.spoused the interests 

 of the PaliEontology, and of every other department of the N.atural History of the State of New York. 

 A wise legislator and educalo)-, a faithful and unswerving friend and counselloi- of many years, his name 

 deserves to be spoken with respect and reverence wherever geologic science shall be taught or studied, 

 throughout the civilized world. 



