NO. 24 PTARMIGANIA STRATA RESSER 65 



PAGE 



Acrothele artemis Walcott 21 



ig. Exterior dorsal valve (X 2.5). 



20. Ventral valve (X3). 



21. Dorsal valve (X2). 



22. Holotype dorsal valve (Walcott fig. 54) (X 2). 



Acrothele parilis, new species 21 



23. Exterior of ventral valve (X3)- 



24. Interior of ventral valve (Walcott fig. 3e) (X 3)- 



25. Dorsal valve (Walcott fig. ig) (X3). 



Acrothyra minor Walcott 22 



26. Holotype ventral valve (Walcott fig. 4) (X 6). 



27. Ventral valve (Walcott text fig. 59) (X 5)- 



28. Interior ventral valve (Walcott fig. 4a) (X6). 



29. Ventral valve (Walcott fig. 4b) (X7). 



Lingulella eucharis Resser 22 



30. Dorsal valve ( X 5 ) • 



31. Ventral valve (Xs). 



32. Dorsal valve (Xs). 



Wimanella maladensis, new species 23 



33. 34- Ventral valves (X 1.5). 

 35, 36. Dorsal valves (X 1.5). 

 2,7. Ventral valve (X 3)- 



Helcionella arguta, new species 23 



38-40. Specimens in various attitudes (X2.5). 



41. Another example with Doliclwmctopsis natalis (X 2.5). 

 Helcionella burlingi, new species 24 



42-44. Several examples (X3). 



Locality 59^ 5 miles southwest of Liberty, Bear River Range, Idaho. 

 Helcionella aequo, new species 24 



45-47. Three views of holotype (X 2.5). 



Plate 2 



Hyolitlies prolixus, new species -4 



1, 2. Two examples showing flat side (X i-5)- 



3. Cross section near apical end (X I-5)- 



Pagctia maladensis, new species 25 



4. Pygidium, impression of cranidium, and examples of Acrotreta 



sulcata (X 5)- 



5. right. Holotype cranidium and pygidium (X 5)- 



Pagetia clytia Walcott 25 



5. top and left. Cranidia of P. clytia (X 5). Note in partial cranidium 



below left center occipital spine and curvature of fixigenes to 

 the eye. 



6. Pygidium of usual appearance (X 5)- 



7. Cranidium with occipital spine (X 5)- 



8. Pygidium in matrix to show axial spine (X 5)- 



Bathyuriscus politus, new species 30 



9. Holotype pygidium (X 5)- 



