95 BRACHIOPODS. 



arcbed ; beak incurved and extended but slightly beyond the 

 hinge margin. Surface, aside from the radiating ribs, nearly 

 smooth, marked only by a few lines of growth ; under a mag- 

 nifier the shell is beautifully punctate. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City, Lexington. 



Considerable difference of opinion has long existed as to 

 what name should actually be applied to the form under con- 

 sideration. Two names are perhaps more prominent than any 

 of the others, as these were both published the same year. 

 They are the titles proposed by Shumard and by Marcou. 

 Bearing upon this question, White seems to have found the 

 most conclusive evidence of the priority of Marcou's term by 

 a few months. He says : "Orthis pecosi, Retzia mormoni, Rhyn- 

 chonella uta, R. rockymontana and Spirifera rockymontana were 

 published in his Geology of North America. I have obtained 

 satisfactory evidence that the work was published as early as 

 March 1, 1858." Volume XV of the Bulletin de la Societe Ge- 

 ologique de France contains a statement that a copy of the 

 book was sent to that society on April 20, 1858. In the eame 

 year Shumard and Swallow published a paper containing de- 

 scriptions of the three first-named species, under other names, 

 in the Transactions of the St. Louis Academy of Sciences, but 

 that publication was not made until about the first of June. 

 In December of the same year, Hall published in the Geological 

 Report of Iowa, Spirifer rockymontana as S. opimus ; and in 

 1860 McChesney published 72. rockymontana as R. etoniceformis. 

 It thus is clear that Marcou is entitled to priority of all five 

 of the names above given. 



Trematospira imbricata? (HALL). 



Leptoccelia imbricata Hall, 1857 : Ann. Kept. N. Y . State. Mus. Nat. Hist., 

 p 108. 



Leptoccelia imbricata Hall, 1859 : Pal. New York, vol. Ill, p. 246, pi. xxxviii, 



figs. 8-13. 

 Trematospira imbricata Meek & Worthen, 1868 : Oeol. Sur. Illinois, vol. Ill, 



p. 381, pi. vii, tigs. 2a-e. 



Shell small, rhombic-suborbicular, plano-convex, or con- 

 cavo-convex; length sometimes a little greater, and in other 



