BRracHIopopDA. 821 
on the opposite valve subserving to some extent purposes of 
articulation. Spirals duplicate and echinate; spiral cones 
depressed. 
Fias. 410, 411.— Koninckodonta Fuggeri, Bittner. (BrrTner.) 
Type, Koninckodonta Fuggeri, Bittner. 
Distribution. Triassic. 
Thecospira, Zugmayer. 1880. 
Shells small, concayvo-convex, attached by the umbo of the 
pedicle-valve. Surface smooth or concentrically rugose; covered 
with a tubercled periostracum. Shell substance perforate. 
Cardinal area and deltarium well-developed. In the pedicle- 
valve the teeth are conspicuous and unsupported; a median 
septum divides the deeply impressed muscular scars. In the 
brachial valve the cardinal process is large, elevated, tripartite on 
the summit, deeply grooved in the middle. Spiral cones double, 
directed toward the lateral slopes of the pedicle-valve. The 
Fias. 412, 413.— Thecospira Haidingeri, Suess(sp.). (ZUGMAYER.) 
jugum is a simple arch, broadened at its summit and con- 
tinued into intercalary lamellae which are coextensive with 
the principal coils. The latter are fimbriated on their outer 
margins. ' 
Type, Thecospira Haidingert, Suess (sp.). 
Distribution. Triassic. 
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