340 



MOLLUSCOIDEA BRACHIOPODA 



SUB-KINGDOM V 



Pomatospirella, Bittner. Small smooth shells having the contour of Dayia 

 or Cydospira. Alpine Trias. 



Kayseria-, Davidson. Lenticular, plicated shells with a median plicated 

 sinus on both valves. Jugum with a ventral articulating process and the 

 bifurcations continued between the spiral ribbons to their outer ends. 

 Devonian ; Germany. 



Diplospirella, Bittner. Athyroids with the jugal processes coextensive 

 with the principal spiral coils. Alpine Trias. 



Pexidella, Bittner. Athyroids differing from Diplospirella in that the 

 jugum is much reduced and situated in the umbonal region. Valves much 

 thickened in the apical region. Alpine Trias. 



Euractinella, Bittner. Diplospirelloids with short corresponding ribs. 

 Alpine Trias. 



Anisadinella, Bittner. Diplospirelloids with alternating ribs. The 

 secondary spiral coils give off a process which returns and joins the jugum. 

 Alpine Trias. 



Koninckina, Suess (Fig. 584). , Shell sub-orbicular, concavo-convex, smooth, 

 with a straight hinge-line, or Strophomenoid in external appearance. Car- 



FIG. 584. 



Koninckina. Leonhardi, Wissin. sp. 

 Upper Trias ; St. Cassian, Tyrol. A, Shell 

 showing spiralia, enlarged. B, Ventral 

 and dorsal aspects, 1/1- 



FIG. 585. 



Amphiclina, with re- 

 stored brachidia (after 

 Bittner). 



FIG. 586. 



TJiecospira Haidingeri, Suess sp. 

 Rhaetic ; Starhemberg, Austria. 

 A, Ventral valve, 1%. B, C, 

 Brachidia, enlarged (after Zug- 

 meyer). 



dinal area obsolete at maturity. The accessory spirals take their origin 

 from the upper surface of the jugum, and are coextensive with the primary 

 spirals. Trias ; Europe. 



Amphiclina, Laube (Fig. 585). Like Koninckina, but sub-trigonal in out- 

 line, and with well-developed cardinal area and deltidial plates. Trias and 

 Jura ; Europe. 



Koninckella, Munier-Chalmas. Similar to Amphiclina, but with well- 

 developed cardinal process. Trias and Jura ; Europe. 



Amphidinodonta, Bittner. Like Amphiclina, but with interlocking denti- 

 culate ridges and tubercles within the margins of the valves. Alpine Trias. 



Koninckodonta, Bittner. Like Koninckina, but with prominent cardinal 

 areas and a row of sub-marginal thickened tubercles on the interior of the 

 ventral valve, which interlock with similar callosities on the dorsal valve. 

 Alpine Trias. 



Thecospira, Zugmayer (Fig. 586). Ventrally cemented Koninckinae with 

 well-developed cardinal area and cardinal process. Alpine Trias. 



