BRACHIOPODA. 369 
with corresponding ribs; hinge-line wide and straight, with a 
narrow area to each yalye; foramen large, deltidium rudi- 
mentary ; interior of dorsal valye with one or more prominent, 
sub-marginal septa; loop two or four-lobed, adhering to the 
septa, and more or less confluent with the valve 
SS 
———— 
Ra eR Vv ae, \ 
SSA 
AY) 
yi WS) 
NNN oy 
\ 
Fig. 162. A. decollata, *° ; dorsal valve with the animal, from a specimen dredged 
by Professor Forbes in the AXgean. The oral aperture is seen in the centre of tlie 
disk. 
Animal with oral arms, folded into two or four lobes, united 
by membrane, forming a brachial disk fringed with long cirri; 
mantle extending to the margins of the valves, closely adherent. 
Distribution, 5 species. North Britain, Madeira, Canaries, 
Mediterranean. 80—105 fathoms. 
Fossil, 19 species. Oolite—. Exrope. 
XE 
OY 
y 
Vera 
¢ ? Z 
Coe 
Fig. 163. Z. radians. Fig. 164. ZT. Mediterraneum.* ‘ 
THECIDIUM, Defrance. 
Etymology, Thekidion, a small pouch. 
Type, T. radians, Pl. XV., Fig. 11. 
Shell small, thick, punctate, attached by the beak; hingze- 
* Dorsal valve with the animal, magnified, Coll. Davidson, 
Rd 
