BRACHIOPODA. 33 



McCoy's first species of his genus was S. decorus, Phillips, which Davidson 

 has regarded equivalent to Martin's earlier name Anomites glaher, a well known 

 and widely distributed Carboniferous species. 



American representatives of this type of structure are of exceedingly rare 

 occurrence. Dr. Davidson has identified S. glaber in the Carboniferous lime- 

 stone of Nova Scotia,* and Meek and Worthen have described S. glaber, var. 

 contractus, from the Chester limestone of Illinois. 



It has also been stated that the species S. glaher occurs in the Devonian, but 

 it would seem that such identifications should be carefully reviewed. Davidson, 

 in his description of the Carboniferous brachiopods (p. 62), mentioned the fact 

 that he had certain forms from the English Devonian which he considered in- 

 distinguishable from this Carboniferous species but he did not describe them 

 at greater length, nor illustrate them. The shell called S. glaber by Kayser 

 (Zeitschrift der deutsch. geolog. Gesellsch., Bnd. xxiii, p. 581, pi. xii, fig. 1, 1871), 

 from the middle Devonian of the Rhine, is evidently quite distinct from, this 

 species. Mr. Walcott has described under the name S. (Martinia) glaber, var. 

 Nevadensis, a shell from the Eureka District of Nevada, which is stated to possess 

 a surface bearing " obscure radiating plications, concentric striae about 1 mm. 

 distant [from each other], also fine radiating interrupted striae " (Monographs 

 U. S. Geological Survey, viii, p. 139, 1884). Both the description and the illus- 

 trations given of this fossil suggest the Devonian species S. euryglossus, Schnur, 

 which, like H. curvatus, Schlotheim, is a fimbriate species belonging to the 

 pauciplicate or S. /tft'w-group of the unicispinous section. Prof H. S. Williams 

 (The Life-History of Spirifer lavis; Ann. N. Y. Acad. Sci., vol. ii, No. 6, pp. 16 

 et seq., 1881) has endeavored to demonstrate a lineal relationship between 

 S. glaber and S. lavis of the lower Portage group, the latter a fimbriate species, 

 the former non-fimbriate. In Mr. Walcott's work, referred to, this idea is 

 carried to its logical extreme, the author referring the fimbriate species, S. 

 undiferus, F. Roemer, S. fimbriate, Conrad, S. subundiferus, Meek and Worthen, 

 etc., to the genus Martinia together with S. glaber (pp. 144-146), and taking 

 no note of the highly important difference between the fimbriate Spirifers 

 with simple and with compound spines. 



♦Quarterly Journal Geological Society, 1863, p. 170. 



