BRACHIOPODA. 405 



Rafinesqulna alternata.] 



1843. Orthis huronensis CASTELNAU. Essai sur le SysWrne Silurien de I'Amfirique Septentrionale, 



p. 37, pi XIV, flg. 6. 



1843. Orthis plana CASTELNAU (not PANDER). Ibidem, p. 38, pi. xiv, flg. 1. 



1844. Strophomena angulata? OWEN. Geological Explorations in Iowa, Wisconsin and Illinois, 



pi. xviii, flgs. 1, 3. 

 1847. Leptcena alternata HALL. Paleontology of New York, vol. i, pp. 102, 286, pi. xxxi, flg. 1; 



pi. xxxiA, flg. 1; pi. LXXIX, flg. 2. 



1856. Strophomena alternata BILLINGS. Canadian Naturalist and Geologist, vol, i, p. 204, flgs. 3, 4. 

 1858. Leptcena alternata ROGERS. Geology of Pennsylvania, vol. ii, pt. i, p. 818, flg. 600. 

 1860. Strophomena alternata BILLINGS. Canadian Naturalist and Geologist, vol. v, p. 51. 



1862. Strophomena alternata BILLINGS. Palasozoic Fossils, vol. i, p. 117. 



1863. Strophomena alternata BILLINGS. Geology of Canada, p. 163, flg. 140. 



1865. Strophomena anticostiensis SHALEB. Bulletin of the Museum of Comparative Zoology, vol. i, 



p. 62. 



1873. Strophomena alternata MEEK. Palaeontology of Ohio, vol. i, p. 88, pi. vn, flg. 1. 

 1875. Strophomena alternata MILLER. Cincinnati Quarterly Journal of Science, vol. ii, p. 51, 



1880. Strophomena alternata WHITE. Second Annual Report of the Indiana Bureau of Statistics 



and Geology, p. 481, pi. i, flgs. 6, 7. 



1881. Strophomena alternata WHITE. Tenth Report State Geologist of Indiana, p. 113, pi. I, 



flgs. 6, 7. 

 1883. Strophomena alternata HALL. Second Annual Report N. Y. State Geologist, pi. xxxvin, 



flgs. 6-11. 



1887. Strophomena alternata SHALER. Fossil Brachiopoda of the Ohio Valley, p. 4, pis. n, in. 

 1892. Raflnesquina alternata HALL. Palaeontology of New York, vol. viii, p. 281, pi. vm, flgs. 6-11. 



Conrad did not define nor describe this species, but gave it the Ms. name 

 Leptcena or Strophomena alternata, under which it became known to the geologists of 

 the New York survey. Emmons published a figure of it in 1842, but Prof. Hall, in 

 1847, was the first to describe it as Conrad's species. In 1843, however, Casteluau 

 described and illustrated the same species as Orthis huronensis, and were it not for 

 the previously published figure of Emmons this name would have to be adopted. 

 8. angulata Owen is probably a misprint for S. alternata, since the identification is 

 queried, and his initial is not added to the name, as was Owen's custom with all new 

 species. 



The following detailed description is that of Meek, from which a few paragraphs 

 relating to varieties have been omitted: "Shell attaining a large size, semioval, the 

 breadth being nearly always greater than the length; hinge-line as long as the 

 breadth of the valves at any point farther forward, or somewhat longer; lateral 

 extremities rectangular, sometimes compressed and moderately deflected; lateral 

 margins a little convex, or slightly sinuous posteriorly, and rounding forward to the 

 front, which is semicircular in outline. 



"Dorsal valve flattened in the umbonal and cardinal regions, and gently or more 

 or less strongly concave in the central and anterior portions, and curved upward 

 around the anterior and lateral margins; beak small, but projecting slightly beyond 

 the edge of the area, which is very narrow or sublinear, and directed nearly back- 

 ward. Interior with cardinal process strong, directed obliquely forward, with its 

 two divisions distinctly diverging, and flattened and longitudinally striated on their 

 posterior faces; sockets for the reception of the teeth of the other valve rather well 



