58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I48 



(Codell Sandstone Member) of the Carlile Shale, where it is found in 

 limestone and calcareous sandstone lenses throughout the unit. 



In Colorado, the species has been found at localities 40-43, 55, and 

 58-61 ; in New Mexico, at locality 45 ; in Texas, at localities 15, 44, 

 46-54, 56, and 57, described in detail at the end of this report. 



Illustrated and measured specimens. — The holotype is presumed to 

 have been lost in the fire at the St. Louis Academy of Science. Neo- 

 type, here selected, a mature left valve (pi. 3, fig. 11), U.S.N.M. 

 132222. White's hypotypes, paired valves (1879; 1884), illustrated 

 on plate 3, figure 13, U.S.N.M. 12383; White's "paratype" of O. 

 (A.) hlacki (1884, pi. 46, fig. 2), U.S.N.M. 8024b. Stanton's 

 hypotypes (1893 [1894], pi. 4), U.S.N.M. 11822a (Stanton's fig. 8), 

 U.S.N.M. 22860b, c, d (Stanton's figs. 9, 6, 4, respectively), 22861 

 (Stanton's fig. 7). New hypotypes, U.S.N.M. 8024a, c. d; 

 U.S.N.M. 11882b; U.S.N.M. 22009a, b; U.S.N.M. 2201 lb; U.S.N.M. 

 132213-132221, inclusive, U.S.N.M. 132223-132244, inclusive; 

 U.S.N.M. 132250, 132251, 132283, 132284, 132305-132308; 

 U.M.M.P. (University of Michigan Museum of Paleontology) 38038, 

 38039, 38041, 43466, 43478, 43482, 43483. Measured specimens, 

 unfigured: U.S.N.M. 8024e, U.S.N.M. 11882c, U.S.N.M. 22009; 

 U.S.N.M 22011c; U.S.N.M. 22860e, U.S.N.M. 132245-132249, 

 inclusive; U.S.N.M. 132291-132300, inclusive, 132304. 



LOPHA BELLAPLICATA BELLAPLICATA var. A 



Plate 6, figures 1-6, 19 



DESCRIPTION 



Material. — 36 left and right valves, moderately well preserved, 

 from the Codell Sandstone Member. ("Pugnellus Sandstone"), Car- 

 lile Shale, at a number of localities in Huerfano Park, Colorado. The 

 collection includes mostly small individuals, forming a partial growth 

 series. 



General form. — Summary of measurements presented in tables 

 3, 4. Shell small, inequivalve, left (lower, attached) valve much 

 more convex, slightly larger, less curved dorsally than right ; most 

 valves slightly inequilateral, prosocline to erect. Highly variable in 

 outline: typically elongate-ovate along midline axis (pi. 6, figs. 1, 

 2, 5) less commonly broadly subovate due to lateral flaring of pos- 

 terior or posteroventral margins (pi. 6, figs. 6, 19), or irregularly 

 elongate due to crowded growing conditions. Height greater than 

 length. Anterior margin steeply inclined, straight to slightly and 



