828 Report oF THE STATE GEOLOGIST. 
i 
coalesced with the lateral walls of the pedicle-valve and the 
teeth upon the margins of that valve. Hinge-plate small, divided 
by a shallow incision. Cardinal process absent. 
Type, Welsonia Wilsoni, Sowerby (sp.). 
Distribution. Upper Silurian — Lower Devonian. 
Uncinulus, Bayle. 1878. 
(Plate 44; figs. 6-9.) 
Synonym; Uncinulina, Bayle, 1878. 
Shells exteriorly like Wisonta; interiorly with a solid, undi- 
vided hinge-plate and a highly developed cardinal process. 
Type, Uncinulus subwilsoni, dOrbigny (sp.). 
Distribution. Devonian. 
Hypothyris, (McCoy) King. 1850. 
(Plate 44, figs. 10-18.) 
Shells strongly subcuboidal. Teeth usually supported by short 
vertical lamelle ; hinge-plate quite small and composed of two 
broad, short lateral processes, which are divided, for a portion of 
their length only, by a median incision extending to the bottom of 
the valve but not forming an inceptive spondylium as in Camaro- 
_ta@cuta. Dental plates large. There is but the barest indication 
of a median septum in the brachial valve. Muscular impressions 
small and not deep; those of the pedicle-valve making an oval 
scar continued from the narrow pedicle-cavity; those of the 
brachial valve being narrow, elongate and extremely obscure. 
Interior of the pedicle-valve frequently preserving the ovarian 
pittings and vascular sinuses while the characters are but faintly 
retained on the brachial valve. 
Type, Hypothyris cuboides, Sowerby (sp.). 
Distribution. Devonian. 
Subgenus Pugnax, Hall. 1893. 
(Plate 44, figs. 14-25.) 
Shells with deep fold and sinus; elevated, and often acuminate 
on the anterior margin; more or less sharply plicated, the 
plications usually being simple, those of the fold and sinus the 
strongest, and those of the lateral slopes often obscure or 
obsolete. Pedicle-valve shallow; brachial valve deep. Teeth 
supported by vertical lamelle; hinge plate similar in structure 
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