86 COLORADO FORMATION AND ITS INVERTEBRATE FAUNA, [bull. 106. 



of the Platte river and New Mexico have brought in specimens of it, 

 but almost always in a distorted or broken condition. Its distortion, 

 however, is evidently not always due to accident, since it often resulted 

 from one of the depressions between two of the undulations being so 

 much larger and deeper than the others, as to give the valves a remark- 

 ably constricted appearance. In other cases it resulted, in part at least, 

 from the great irregularity in the size of the undulations themselves. 

 Although it is often found distorted in general form by accidental pres- 

 sure, it was evidently also naturally quite variable in outline, partic- 

 ularly in convexity." 



The name Inoceramus deformis was first used by Meek in a list with- 

 out description, but with a reference to Hall's figure iu Fremont's re- 

 port. Conrad refers to the same figure in describing Haploscapha capax. 

 His genus Haploscapha was based on specimens, probably belonging 

 to this species, in which the surface of the shell was completely covered 

 and cemented together by Ostrea congesta so that the interior only 

 could be seen. 



Inoceramus erectus Meek, from the upper portion of the Cretaceous 

 section at Coalville, Utah, is closely related to this species, though it 

 occurs at a much higher horizon. It seems, however, to be a more con- 

 stant and regular form. 



Locality and position. — Very common in the Niobrara limestone along 

 the eastern base of the Front range in Colorado, e. #., at Boulder, Mor- 

 rison, Canyon city, Colorado Springs, near Pueblo, and in Huerfano 

 park. In this region it seems to be con lined to the Niobrara. It is 

 also common in Kansas and Nebraska, and I have seen specimens that 

 probably belong to this species from the Austin limestone, near Dallas, 

 Texas. 



Inoceramus conradi H. and M. 



Inoceramus conradi Hall and Meek, 1856, Mem. Am. Acad. Arts, and Sci.,n. s., vol. v, 

 p. 387, PI. 2, Figs. 5d and b. 



This species is based on a single imperfect, crushed specimen which 

 was obtained from the lower part of the Fort Benton shales on the Mis- 

 souri, 5 miles below the mouth of Vermilion river. No other examples 

 of it have been recorded, probably because well-preserved specimens 

 could not be identified by means of the figure. 



MYTILID^E. 

 Genus MODIOLA Lamarck. . 



MODIOLA (BrACHYDONTES) MULTIL1NIGERA Meek. 



PL xix, Fig. 3. 



Modiola (Brachydonles) multilinigera Meek, 1873, Ann. Rept. U. S. Geol. Sur. Terr, for 



1872, p. 492. 

 VoUella (Brack y do ntes) multilinigera White, 1880, Cont. to Paleontology Nos. 2-8, p. 

 14, PI. 12, Figs. 15a and &.< Ann. Rept. U. S. Geol. Sur. Terr, for 1878. 



