338 MOLLUSCOIDEA—BRACHIOPODA SUB-KINGDOM V 
Parazyga, Hall and Clarke (Fig. 579). Like Trematospira, but with the 
fine, simple ribs covered with very delicate, short, hair-like spines. De- 
vonian ; North America. 
Eumetria, Hall. Elongate terebratuliform shells with numerous fine 
radiating striae. Hinge-line short. Dorsal hinge-plate very complicated. 
; Jugum similar to that of Letzia, but the terminally 
bifurcated process is extended backward at an abrupt 
angle, and terminates just in front of the apices of the 
primary lamellae. Shell structure punctate. Lower 
Carboniferous ; North America and Europe. 
Acambona, White. Carboniferous ; North America. 
Hindella, Davidson (? Whitfieldella, Hall and Clarke). 
Ovate or elongate, sub-equally convex, smooth, Athyroid 
shells. The V-shaped jugum has a short, acute process. 
A dorsal median septum present. Silurian and De- 
vonian ; North America. 
Hyattella, H. and C. Similar to Whitfieldella, but 
compactly sub-pentahedral, and without the dorsal 
areca * median septum. Silurian; North America. 
Parazyga hirsuta, Hall. De.  Nucleospira, Hall (Fig. 580). Sub-cireular, biconvex 
es Tet thenatn; Shells with numerous, fine, short spinules. Jugum with 
tucky. A, Shell of thenatural " ‘ : 3 
size. B, Same with dorsal a long, straight, simple process. Silurian to Lower 
ee ee ee Hinze. Carboniferous; North America and Europe. 
aera ee Anoplotheca, Sandberger (Bifida, Davidson). Concavo- 
convex small shells with few plications, crossed by fine, 
often imbricating growth lines. Jugum originating near the mid-length of 
the primary lamellae, uniting and forming a simple upright stem articulating 
in a cavity in the ventral valve. Dorsal 
valve with a high median septum. De- 
vonian ; Germany and France. 
Coelospira, Hall (Leptocoelia, Hall). 
Shells externally much like Atrypa, but 
with laterally directed spirals. Jugum 
similar to that of Anoplotheca. Silurian 
and Devonian; America, Europe, and 
South Africa. 
Anabia, Clarke. Similar to Coelo- 


Fic. 580. 
spird, but with a highly convex dorsal Nucleospira pisum, Sow. Silurian ; Wenlock, Eng- 
valve. Silurian ; Brazil. land. A, Interior of dorsal valve. 3B, Vertical 
section through both valves, 5/s (after Davidson). 
Vitulina, Hall. Like Coelospira, but 
with few plications and a long hinge-line. Plications covered with fine 
radiating lines or rows of pustules. Devonian; America and South Africa. 
Meristina (Whitfieldia, Davidson), (Fig. 581). Biconvex, smooth-shelled 
Athyroids. Jugal stem with a short bifurcation. Silurian; North America 
and Europe. 
Glassina, Hall and Clarke. Like Jeristina, but with the bifureations of 
the jugum originating directly from its apex. Silurian; England. 
Athyris, M‘Coy (Spirigera, VOrbigny ; Euthyris, Quenstedt), (Fig. 582). 
