I56 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I48 



Table 34. — Measurements of selected specimens of Torynechus caelatus from the 

 Leonard Formation in the Glass Mountains, Tex. 



Measurements, in millimeters 



USNM No. 

 142548 

 142549 

 142550 

 142551 

 142552 

 142553 

 142554 

 142555 



mens were collected at U.S. National Museum locality 702, about the 

 same number at 702un, and about 30 at other localities in the forma- 

 tion. These are in the vicinity of Split-tank on the old Word Ranch, 

 Hess Canyon Quadrangle, Tex., near R. E. King's (1931) locality No. 

 128. 



Genus SEPTACAMERA Stepanov 1937 



Septacamera STEPANOV, D. L., 1937, Uchenie Zapiski, Leningrad, No. 16, p. 



146, 149. 

 Septocamera Stepanov, LICHAREV, B., I960, Osnovi Paleont., p. 249 (altered 



spelling). 



Shell large, uncinuliform strongly biconvex; outline transversely 

 subtrigonal to subelliptical or subpentagonal, widest near midlength ; 

 profile subtrigonal, with anterior surface gently arcuate, valves meet- 

 ing at high angle, butting at anterior, apparently with little or no over- 

 lap of edges on posterolateral slopes ; commissure strongly uniplicate, 

 but fold not standing high above flanks ; sulcus shallow, tongue extend- 

 ing into fold strongly bent to form flattened anterior surface ; costae 

 strong, sharp or sharply curved in cross-section, beginning at beaks or 

 only slightly anterior, somewhat broadened and lowered on anterior 

 surface, normally simple, without bifurcation or intercalation; stolid- 

 ium entirely absent ; growth lines fine, closely spaced ; growth laminae 

 slightly stronger. 



Pedicle valve flatly to moderately convex for most of length, 

 strongly convex near anterior, bending toward commissure ; beak 

 short, blunt, suberect to erect; delthyrium small, triangular, largely 

 occupied by brachial beak ; deltidial plates small, leaving oval foramen 

 open. 



Brachial valve more strongly convex, especially laterally toward 

 flanks, strongly bent near anterior of fold, meeting pedicle valve at 



