122 University of Texas Bulletin 



GERVILLIOPSIS INVAGINATA (White) 



1888: Dalliconcha invaginata White, Proc. Acad, Nat. Sci., Phila., p. 35, pi. 2, figs. 4-5. 



1889: Gervilliopsis invaginata Hill: Geol. Surv. Texas Bull. 4, p. 9. 



1896: Gervilliopsis invaginata Stanton and Vaughan, Am. Journ. Sci., IV series, vol. 1, 



vol. 1, pp. 21-26. 



1910 : GervUleia invaginata Bose, Inst. Geol. Mex., Bol. 25, p. 87. 



1920: Gervilliopsis invaginata Adkins and Winton, Univ. Texas Bull. 1945, p. 67, pi. 18, 

 fig. 1. 



This shell abounds in the lower Weno of Cooke County, where on fresh 

 exposures it is found with the nacreous shell intact. It has a restricted 

 vertical range and is a reliable marker for the basal Weno north of the 

 Brazos River. It has not been reported from South Central Texas. 



Stanton and Vaughan, however, record the species from subdivision 6 

 (Weno-Pawpaw) of Cerro de Muleros. 



OSTREA CARINATA? Lamarck 



The known distribution of carmata-like species in Texas has already 

 been published. 1 Pervinquiere- has figured types of Ostrea carinata Lam- 

 arck ; and Texas material is now being assembled for a critical study and 

 comparison with related European material. Oysters of the group of 

 0. carinata and widespread in North, Central and West Texas at different 

 stratigraphic levels, and among them a zone of abundance of the smaller 

 forms in the upper part of the Weno limestone (Quarry group of North 

 Texas) and a scattering representation in the Pawpaw formation. 



OSTREA sp. aff. DILUVIANA Linnaeus 



There are in the Weno and Pawpaw formations three oysters with zig- 

 zag coarse margins and ribbed valves, resembling the group of Ostrea 

 diluviana. One of these occurs in the Weno and Mainstreet limestones 

 and is similar to that figured by Hill from the Austin Chalk (U. S. G. S.. 

 21st Ann. Kept., pt. 7, pi. XLV, fig. 2). Another species from the Weno 

 marl is smaller and thinner, and the margins are crenulate (Univ. Texas 

 Bull. 1945, pi. 16, fig. 1). A third unfigured species from the Weno marl 

 has few prominent zigzag ribs of varying height. These species will likely 

 be found to have considerable vertical range. 



1 Winton and Adkins, Univ, Texas Bull. 1931, p. 57; Adkins and Winton, Univ. Texas 



Bull. 1945, p. 59. 

 2 Pervinquiere, Pal. Univ., 3 me ser., 1910, fiches 197-198. 



