94 INVERTEBRATE PALEONTOLOGY. [WHITE. 



75. Trigonella f. Island Park, Utah. Shells rather small-exte- 

 rior nearly perfect, but the hinge is unknown, and they are referred to this 

 genus provisionally. 



76. Undetermined Concliifers. Two species. Flaming Gorge ; north base 

 of Aquarius Plateau; Square-top Butte, east base of Aquarius Plateau, 

 Utah. 



77. Undetermined Conchifer. Different from No. 76. Island Park, Utah. 



78. Myacitcs ?. South base of Thousand-lake Mountain, Utah. 



79. Neritimt- -?." White Hills", south of Twelve-mile Creek, 

 near Gunnison, Utah; and Vermilion Hog-backs, Northwestern Colorado. 



80. Neritinaff Powelli White. Mouth of Thistle Creek, Spanish Fork 

 Canon, Utah. Described on a following page. 



81. Undetermined Gasteropods. Two species, very small, and the speci- 

 mens numerous. Mouth of Thistle Creek, Spanish Fork Canon, Utah. 



82. Eelemnites densus Meek and Hay den. Island Park and Flaming 

 Gorge, Utah; and Vermilion Hog-backs, Northwestern Colorado. 



83. Ammonites cordiformis Meek and Hayden. A small fragment of the 

 inner volutions. Vermilion Hog-backs, Northwestern Colorado. 



CRETACEOUS PERIOD. 



HENRY'S FORK GROUP. 



84. Ostrea prudentia White. Head of Water-pocket Can on, Southern 

 Utah. 



85. Grypliea Pitclieri Morton. Near Twin Mesas; Upper Pine Creek; 

 near Last,Chance Creek; head of Water-pocket Canon and Lower Potato 

 Valley, Southern Utah. The specimens are numerous, and show the usual 

 extreme variations. It occurs also in the Sulphur Creek Group. (See No. 9 7.) 



86. Exofiyra Icevinscula Roemer. Lower Potato Valley and south base 

 of Mount Killers, Southern Utah. It occurs also in the Sulphur Creek Group. 

 (See No. 98). 



87. Exogyra ponderosa Roemer. Head of Water-pocket Canon, South- 

 ern Utah. It occurs also in the Sulphur Creek Group, in Utah, and was 

 obtained from a locality in Middle Park, Colorado. (See Nos. 99 and 202.) 



