BRACHIOPODA — TELOTREMATA, 



299 



LXXXVI. Peregrinella GEhlert. 



Shell large, pedicle valve generally the more convex. Valves 

 without median fold or sinus ; with even margins and plicated sur- 

 faces. Beak short, false cardinal area and deltarium present. 

 Cretacic. 



287. P. whitneyi (Gabb.). (Fig. 371.) Cretacic. 

 Large, subcircular in outline; the two valves about equally 



convex. No median fold or sinus present. Surface marked with 



40 to 50 narrow, angular plications 



which are equal in breadth to the deep, 



angular interspaces. When young the 



shell is much longer than wide. Length 



and breadth each about IJ{ inches in 



maturity. 



Knoxville of California. 



LXXXVII. Centronella Billings. 



Usually small, terebratuloid in out- 

 line. Pedicle valve convex, angular in 

 the center ; beak acute and incurved 

 with a terminal foramen, which is con- 

 tinuous with a partially closed delthy- 

 rium. Brachial valve plane or concave, 

 depressed into a median sinus. Brachid- 

 ium in two branches uniting medially into a triangular plate bear- 

 ing a median ridge. Devonic-Mississippic. 



288. C. glansfagea Hall. (Fig. 372, a-c.) Devonic. 

 Very small, broadly ovate. Pedicle valve much the larger, reg- 

 ularly arcuate from beak to front ; beak much extended and 

 strongly incurved. Brachial valve convex above and concave in 



Fl G . 371. Pe regrin el la 

 whitneyi. (After Stanton. ) 



A A 



Fig. 372. a-c, Centronella glansfagea. (After Nettelroth.) d-e, C. impressa. 



(Pal. N. Y., IV.). 



