NO. 2 BRACHIOPOD SUPERFAMILY STENOSCISMATACEA GRANT 73 



phorium braced against hinge plate in extreme apex, gradually lower- 

 ing toward anterior. 



Type species. — Camarophoria Hamburg en sis Weller, 1910, Bull. 

 Geol. Soc. America, vol. 21, p. 500, fig. 2, (by original designation of 

 Cooper, 1942). 



Comparisons. — Sedenticellula is characterized by its normally flat 

 shell with low fold and shallow sulcus, its numerous fine costae that 

 begin at or near the beaks, and may increase in number anteriorly by 

 intercalation and bifurcation. Internally, it is distinguished by its 

 spondylium that remains sessile for 1 or 2 millimeters from the pedicle 

 beak, somewhat farther anterior than in other genera. 



The other stenoscismatacean genus that most nearly resembles Se- 

 denticellula externally is Camarophorinella Licharev, which also has a 

 low fold and numerous low costae that begin far posterior and may bi- 

 furcate. Sedenticellula differs in its lower fold, weaker costae, and 

 especially in its undivided hinge plate and strong intercamarophorial 

 plate. Torynechus Cooper and Grant also has bifurcating costae, but it 

 is clearly distinguished from Sedenticellula by its uncinuliform exte- 

 rior. No other genus of the superfamily resembles Sedenticellula 

 strongly. 



Range. — Sedenticellula has been found only in the Mississippian 

 (Kinderhook), in Illinois and Texas. 



SEDENTICELLULA HAMBURGENSIS (Weller) 



Plate 4, figs. l-2b ; figure 14 

 Camarophoria hamburgensis WELLER, S., 1910, Bull. Geol. Soc. America, vol. 



21, p. 500, fig. 2; WELLER, S., 1914, Illinois State Geol. Survey Monogr. 1, 



p. 170, fig. 2, pi. 23, figs. 52-60; COOPER, G. A. 1942, Journ. Wash. Acad. 



Sci., vol. 32, No. 8, p. 231. 

 NOT Sedenticellula aff. S. hamburgensis (Weller) CLOUD, P. E., Jr. and 



BARNES, V. E., 1948, Univ. Texas Pub. 4621, pi. 44, figs. 12-16 (S. sacra 



n. sp.). 



Shell small for genus, flatly to strongly biconvex; outline slightly 

 elongate subovate to slightly transverse subelliptical ; commissure 

 uniplicate : low fold beginning slightly anterior to pedicle beak. Costae 

 distinct, beginning at or slightly anterior to beaks, crests and troughs 

 about equal in width, rounded or bluntly V-shaped, normally simple, 

 without bifurcation or intercalation, numbering five to seven on fold 

 and sulcus, four to six on each side. Growth lines fine, closely spaced, 

 producing weak, chevron-shaped ornamentation; slightly stronger 

 growth laminae at irregular intervals. 



Pedicle valve flatly convex, outline subovate ; beak blunt, prominent 

 but not attenuate, suberect ; beak ridges sharp, outlining flattened 

 posterolateral area ; delthyrium broadly triangular, nearly filled by beak 



