PLATE XLIV. 



" All the flgares on this plate are magnified ahout twenty diameters. 



Page. 



Fig. 1. EUETCHILINA RETICULATA Ulrlch 660 



A perfect left valve of this species. Lower third of the Trenton shales, Fillmore 

 county, Minnesota. 



Fig. 2. Ettrtchilina reticulata, var. ikcurva, n. var 660 



Left valve from the upper third of the Trenton shales at St. Paul, Minnesota. 



Figs. 3 and 4. Eurychilina subradiata Ulrich 661 



3. Interior of a perfect right valve. 



4. Nearly perfect left valve, showing the usual characters of the species as it occurs 



in Minnesota. 

 4a. Section of same across central portion of valve. 



Lower third of the Trenton shales, Minneapolis, Minn. 



Figs. 5 to 7. Eurychilina (?) SYMMETRICA, n. sp 663 



(See also plate XLV, figs. 4-6.) 



Interior of a right valve. 



Exterior and anterior views of a more elongate left (?) valve. 

 Upper third of the Trenton shales, St. Paul, Minn. 



Figs. 8 to 11. CtbNOBOLBINA FULCRATA, n. sp 674 



Lateral and posterior views of a left valve, presenting the usual characters of 



the species. 

 Lateral and dorsal views of a right valve, resembling in certain respects the next 



species. 



Upper third of the Trenton shales, St. Paul, Minnesota. 



Figs. 12 to 16. Ctenobolbina crassa Ulrich 675 



Lateral, posterior, and dorsal views of a left valve. This is the original type ^ 

 of the species. Upper third of the Trenton shales, St Paul, Minnesota. 

 15 to 16. Lateral and posterior views of another left valve from the same locality, differ- 

 ing in several respects from the type. 



Figs. 17 to 19. JONESBLLA OBSCURA, n. sp 668 



Left and right valves and an interior view of the first. The "horseshoe " ridge 

 is very obscure in its lower curved part. Galena shales, Cannon Falls, Minn. 



Figs. 20 to 22. Drepanblla biqenekis, n. sp 672 



20 and 21. Side and posterior views of a left valve. Lower Trenton limestone, Minneapolis, 

 Minnesota. 

 22. Longitudinal sectional view across the central part of the same. 



Fig. 23. DiCRANELLA SPINOSA, n. sp 665 



(See also plate xlvt, fig. 41. ) 



A left valve of this species. Middle third of the Trenton shales, Minneapolis, 

 Minnesota. 



Figs, 24 and 25. Dicranella (?) simplex, n. sp 666 



(See also plate xlvi, fig, 4?.) 



Lateral and posterior views of a left valve. Galena shales. Cannon Falls, Minn. 

 In flg. 24 the oblique spine on the left side of the center appears scarcely 

 prominent enough. 



Fig. 26. Dicranella BicoRNis, n. gen. et sp 665 



(See also plate xlvi, figs. 39 and 40,) 



A right valve wanting only the posterior part of the marginal frill. Middle 

 third of the Trenton shales, Minneapolis, Minnesota. 



Figs. 27 and 28. Dicranella marginata, n. sp • • 666 



Lateral and posterior views of a right valve. Trenton shales, near Fountain, 

 Minnesota. 



Figs. 29 to 35. Bythocypris oylindrica Hall, sp 687 



29 to 31. The left side, dorsal, and posterior views of an average example of this species. 

 Lower beds of the Cincinnati group, Cincinnati, Ohio. 



32. View of the interior of a right valve, showing a slight central thicliening of the 



test. From the same locality. 



33. Ventral view of a complete carapace; also from Cincinnati, Ohio. 



34 and 35. Lateral and dorsal views of a small right valve, which is also a little narrower 

 than usual. Galena shales, Cannon Falls, Minn. [oveb. 



