PLATE LXVIII. 



Page. 

 Fig. 1. Crania layois 520 



a. Figure showing general character of the specimen referred to this species. 

 Madison limestone, Crowfoot Ridge, Gallatin Range, top of bed 24. 

 FIG. 2. Orthothetes inflatns. 



a. Figure, after Hall and Whitfield, showing character of an unusually large speci- 

 men. 

 Waverly age, Dry Canyon, Utah. 



Fig. 3, Orthothetes incequalis 522 



a. Figure, after Hall and Whitfield, showing the character of this species. 

 Waverly age, Ogden Canyon, Utah. 

 FIG. 4. Chonetes ornatns 527 



a. View of an average specimen showing outline and surface ornamentation, slightly 



enlarged. 



b. Enlargement of the surface. 



Madison limestone, east side of Gallatin River, west of Electric Peak. 



c. Another, more auriculate specimen, similarly enlarged. 



Madison limestone. 



d. Another, very obese specimen, natural size. 



Madison limestone, east side of Gallatin River, west of Electric Peak. 

 Fig. 5. Chonetes Joaanensis 525 



a. View of type specimen showing slight median sinus; cardinal angles somewhat 



restored ; after Hall and Whitfield. 

 Waverly age, Logan Canyon, Utah. 



b. A characteristic specimen, from Yellowstone National Park, with rounded cardinal 



angles and without a sinus. 

 Madison limestone, Crowfoot Ridge, Gallatin Range, top of bed 25. 



c. A dorsal valve, twice enlarged, showing shape and character of the very finely 



striate surface. 

 Madison limestone, east side of Gallatin River, west of Electric Peak. 



Fig. 6. Productus parviformis n. sp 536 



a. Lateral view of a typical example. 

 b (lower figure). Posterior view of same. 

 c. Outline of same, ventral aspect. 



Madison limestone, Crowfoot Ridge, Gallatin Range, top of bed 25. 

 b (upper figure). A dorsal valve referred to the same species. 

 Madison limestone, south of Forellen Peak, Teton Range. 

 Fig. 7. ProduotusgallatinensisTi.a-p. (Seealsofig.il) 533 



a. Anterior view of a characteristic specimen. 



b. Posterior view of same. 



c. Side view of same. 



Madison limestone, Crowfoot Ridge, Gallatin Range, top of bed 25. 

 586 



