239 



Prof. Hall, who examined a small number of specimens of this 

 species of Spirifera ftftej^-^hre-al^ve-deseTiption was- written, thinks 

 that in its different varieties it is very closely related to several 

 American Devonian Sinriferae : S. varicosa, Corniferous limestone ; 

 S. inedialis, Hamilton group, which varies much in form ; S. angusta, 

 Hamilton group, perliaps only a variety or young fonii of S. medi- 

 alis; and S. macra of the Corn. 1. s., which last species, however, has 

 generally a narrower and more curved hinge area. ^S''. Pedroana 

 therefore appears almost like a connecting link, uniting the above 

 named species in a single series. 



This Sjjirifera is one of the most common and beautiful fossils 

 in the Devonian sandstones at Erere, probably coming next to 

 Streptor'1iyncliu8 Agassizii in abundance. So far as is at present 

 known, it is almost entirely, if not quite confined to the sandstone. 

 But a single very small ventral valve of a Spirifera has been found 

 in the underlying shale, which agrees with the species just described 

 in general outline; it is, however, a little narrower, and appears to 

 have a small median septum which would ally it with Spiriferina ; 

 but this last character is obscure in the specimen, and cannot be 

 relied on. (Morgan -feped^itiens^l870 and '71.) 



[I have taken the liberty to dedicate this beautiful and interesting 

 species to His Majesty, the Emperor of Brazil, an accomplished 

 geological observer, and one whose distingushed patronage and sym- 

 pathy many a scientific traveler in Brazil will remember with the 

 deepest gratitude. — C. F. H.] 



Spirifera ElizaC; Ilartt, sp. nov., Plate VIII, figs. 15 and 21 ; and Plate IX, 

 fig. 22. 



Of tliis species only tlie ventral valve is known. Tliis is of medium size, 

 transverse, the breadth being about twice the length ; nearly semicircular in 

 outline, the sides and front forming a very regular curve, indented only slightly 

 in front by the depression of the sinus ; depressed sub-pyramidal in form, most 

 elevated in the umbonal region. Beak obtusely angular, elevated, not pro- 

 duced beyond the hinge area in the internal moulds. Hinge area triangular, 

 slightly concave and inclining a little backwards ; cardinal margins angular ; 

 fissure triangular. From the margins of the sinus the valve slopes on each 

 side with scarcely any curvature to the cardinal extremities, but from the 

 beak to the front it curves slightly, the sides of the valve presenting there 



