BRAcHIOPoDA. 819 
Karpinskia, Tschernyschew. 1885. 
(Plate 41, figs. 18-20.) 
Atrypoid:shells with elongate form, radially plicated and sub- 
equally convex valves. The spirals have the same positions as in 
Arrypa, though the character of the jugum is still unknown. In 
the pedicle-valve are diverging dental plates, and in the brachial 
valve a median septum. The vascular trunks are simple and 
direct, extending to the anterior margin of the valves without 
branching. 
Type, Karpinskia conjugula, Tschernyschew. Lower De- 
vonian. 
Koninckina, Suess. 1852. 
Shell suborbicular, concavo-convex,smooth. Hinge-linestraight. 
Apex of pedicle-valve incurved, beak full. Cardinal area and 
deltidial plates obsolete at maturity. Spirals double, the prin- 
cipal pair arising from simple crural processes with the extremi- 
ties of which they made a sharp angle. The jugum is formed 
Fias. 402, 408. Koninckina}; reconstruction of the brachial apparatus. (BITTNER.) 
by the anterior extension and union of the crural processes. 
The accessory spirals are coextensive with the main pair 
and take their origin from the upper surface of the jugum. 
The spiral cones are depressed and have their apices directed 
toward the lateral slopes of the pedicle-valve. 
Type, Koninckina Leonhardi, Wissman (sp.). 
Distribution. Triassic. 
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