300 FOSSIL OSTREID^ OF NOETH AMERICA. 



identical with tbis. Professor Eoemer and Dr. Sliiimard obtained their 

 respective specimens Irom the Cretaceous strata of Texas. Dr. Shu- 

 mard described 0. quadriplkaUi in the Transactions of the Saint Louis 

 Academy of Science, Vol. I, page COS, without illustrations. I after- 

 ward obtained copies of his unpublished drawings, and published them 

 together with others in the Annual Eeport of the United States Geolog- 

 ical Surrey of the Territories for 1877, Plate VIII, Figs. 3, a, h. Copies 

 of those figures are given on Plate XLIII. 



Ostrea robusta Conrad. 



(Plate XL, Figs. 3, 4.) 

 Conrad published this form in the Eeport of the United States and 

 Mexican Boundary Survey, Vol. I, page 150, Plate IX, Figs. 3, a, b. 

 His type specimens came from the Cretaceous strata near Laredo, 

 Texas. 



Ostrea (Alectryonia) sannionis White. 



(Plate XLV, Figs. 3, 4, 5, 6, 7.) 



Up to the present time this species has been found only at Coalville, 

 Utah, where a considerable number of specimens were obtained. It is 

 a well marked and apparently constant form. It was first published in 

 Powell's Geology of the Uinta Mountains, and afterward illustrated in 

 the Annual Eeport of the United States Geological Survey of the 

 Territories for 1877, Plate II, Figs. 2, a, b, c, d, e. 



Ostrei soleniscus Meek. 



(Plate XLII, Fig. 1.) 

 This remarkable species is found in the Cretaceous rocks of Southern 

 Wyoming and the adjacent parts of Utah and Colorado. The typical 

 examples are very long and slender, sometimes reaching a length of 

 eighteen inches with a width of only two and a half or three inches. 

 Associated with these long, slender forms, I have found some that are 

 scarcely more elongate than ordinary oysters. In view of the great 

 elongation of one variety of the living Ostrea virginica, such, for example, 

 as is illustrated on Plate LXXXI, I am much disposed to regard these 

 short fossil forms as belonging to the same species as the slender ones 

 with which they are associated. Mr. Meek described 0. soleniscus in 

 the Annual Eeport of the United States Geological Survey of the Terri- 

 tories for 1872, page 487. I gave two figures of it in the same series of 

 reports for 1878, on Plate XI of that volume. 



Ostrea subalata Meek. 



(Plate XXXIX, Fig. 10.) 



The type specimen described by Meek under the name of Ostrea 

 {Griiphwostrea f) subalata in Volume IX of the United States Geological 

 Survey of the Territories, page 15, and figured on Plate 28, Fig. 5, was 

 obtained from the Cretaceous strata of the Upper Missouri Eiver region. 

 It has not since been satisfactorily identified. 



