239 



Prof. Hall, ■who oxamiiiod ji small nniiil)er of specimens of this 

 species of Spirifcra after tlie above description was written, tliinks 

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

 American Devonian Spirifcrae: S. varicosa, Corniferons limestone; 

 S. mcdialis, Hamilton group, which varies much in form ; >S'. angusta, 

 Hamilton group, perhaps only a variety or young form of S. medi- 

 alis\ and S. macra of the Corn. 1. s., Avhich last species, however, has 

 generally a narrower ami more curved hinge area. S. Pedroana 

 therefore appears almost like a connecting link, uniting the above 

 named species in a single series. 



This Spin/era is one of the most common and beautiful fossils 

 in the Devonian sandstones at Erere, probably coming next to 

 Strejytorhynchns 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 Expeditions 1870 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 Elizae^ Ilartt, sp. iiov., Plate VIII, figs. 15 aud 21 ; aud Plate IX, 

 fig. 22. 



Of this species only the ventral valve is known. This is of medium size, 

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

 outline, the sides and front forming a ver\' 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 



