21? 



• > 



rapidly narrowing towards the beak; 

 low, rounded fold, broad below, narrow- 

 ing rapidly towards the beak; fine, low 

 and rounded surface plications and gran- 

 ulose character of the whole exterior of 

 the shell. 



Found in the Demissa bed, at Section 5. 



Spirifer (Reticularia) fimbriatus. 

 (Conrad.) (Fig. 123.) (Pal. N. Y., Vol. 

 IV., p. 214, PI. XXXIII.) 



Distinguishing Characters. — Transverse- 

 ly sub-elliptical outline; hinge line less than 

 rounded cardinal extremities; gibbous and 

 vex valves; rounded sinus; well-marked 



Fig. 122. Spirifer 

 asper. Cardinal and 

 ventral views of a char- 

 acteristic pedicle valve. 

 from the Demissa bed, 

 at Section 5, natural 

 size. (Original.) 



width of shell ; 

 regularly con- 

 fold, abruptly 



Fig. 123. Spirifer fimbriatus. Profile, front, dorsal, and ventral views of a lai'Kf and 

 well-preserved specimen (from Hall). 



elevated in front, low near the beak ; high and concave pedi- 

 cle area; few (six to eighteen on each valve) low, rounded, 

 often obscure, plications ; concentric lamellose and imbricat- 

 ing growth lines, studded with elongated tubercles or 

 spines (fimbria?), which in perfect specimens show lateral 

 fringes or spinules. 



