HOMCOSPIRA, Hatt. 
Page 792. 
Homa@ospira “vax, Hall. 
Figs. 13, 14. Dorsal and profile views of an adult shell. 
Fig. 15. The umbonal region of a young shell in which the deltaria have 
united at the base, inclosing an ovalforamen.  X 7. 
Fig. 16. Similar view of a fully-matured shell; showing the complete obsoles- 
cence of the deltaria and the inclosure of the foramen by the sub- 
stance of the shell. X 2. 
Niagara group. Waldron, Indiana. 
Homa@ospiga APRINIFORMIS, Hall. 
Figs. 17, 18. Dorsal and profile views of the original example. x 2. 
Niagara group. Tennessee. 
Homa@osrira cf. EvAx, Hall. 
Fig. 19. The cardinal portion of the brachial valve; showing the hinge-plate 
and median septum. X83. 
Upper Silurian. Perry county, Tennessee. 
PTYCHOSPIRA, Hatt. 
Page 792. 
PrycHosPira FERITA, von Buch. 
Figs. 20, 21. Dorsal and profile views of an average specimen.  X 2. 
Middle Devonian. Hifel, Germany. 
PrycHOsPIRA SEXPLICATA, White and Whitfield. 
Figs. 22, 23. Dorsal and ventral views of the original specimen.  X 2. 
Kinderhook group. ilinois. 
UNCITES, Dsrrance. 
5 Page 793. 
: Uncirses Grypuus, Schlotheim. 
Fig. 24. A dorsal view of a large individual with distorted, unciform beak. 
(F. R@MER. ) 
Middle Devonian. Hifel, Germany. 
Fig. 25. Aspecimen from which a portion of the pedicle-valve has been broken, 
exposing the interior of the brachial valve and showing the lateral 
pouch-shaped expansions, the incurved beak and the crura. 
(DAVIDSON.) 
Fig. 26. Dorsal view of a specimen of medium size. (DAVIDSON.) 
Middle Devonian. Chimay, Belgium. 
Fig. 27. The interior of the umbonal region of a brachial valve, enlarged ; 
showing the hinge-plate, lateral pouches and grooved ridges extend- 
ing forward from the hinge-plate. (DAVIDSON.) 
Middle Devonian. Torquay, England. 
225 
