CONTENTS xiii 



Page 

 3. Revision of the Families of Loop-bearing Brachi- 

 OPODA — Continued 



Morphogeny from Gioynia to Dallina .... , 303 



Morphogeny from Gwynia to Magellania .... 303 



Conclusions 304 



Classification . . 305 



Family Terebratulidae Gray 306 



Centronellina Waagun . 306 



StringocephalinEe Dall 307 



TerebratulinsE Dall 307 



Dyscolijnae (^Dyscoliidse Fischer and CEhlert 



emend.) .... 307 



Family Tcrebratellidffl King emend 307 



Dallininje n. sub.-fam 307 



Magellaniinte n. sub.-fam 308 



Megathyrinje Dall 308 



References 308 



4. Development op some Silurian Brachiopoda . . 310 



Introduction 310 



List of the Brachiopoda occurring in the Niagara 



Shales at Waldron, Indiana 314 



Discussions of the Species 317 



Cranid siluriana Hall, 1863 317 



Dalmanella elegantula Dalman, 1827 317 



Specific Characters 318 



Mature Form 318 



Incipient Form 319 



Developmental Changes 320 



General Form and Outline 320 



Beaks 320 



Foramen 320 



Plications 321 



Rhipidomella ht/brida Sowerhy, 1S39 . . . . 321 



Leplmna rhomboidalis Wilckens, 1769 322 



Specific Characters 323 



Mature Form 323 



Incipient Form 323 



Developmental Changes 324 



Development of Lepicena rhomboidalis . . . 325 



Orthothetes subplanus Conrad, 1842 ... . . 327 



Specific Characters 328 



Mature Form 328 



Incipient Form . 328 



Developmental Variations 329 



Strophonella striata Hall, 1843 330 



Specific Characters ..... .... 331 



