Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
2 and 3. 
4 and 5. 
6 to 9. 
6 and 7. 
8 and 9. 
10 to 14. 
10 to 12. 
13 and 14. 
15 and 16. 
17 to 21 
17. 
18. 
19 and 20. 
21. 
22 and ? 23. 
22. 
23, 
24 to 26. 
24, 
25. 
26. 
27 and 28. 
29 to 3l. 
29 and 20. 
32 and 33. 
34 to 41. 
36. 
37. 
38. 
39 and 40. 
41. 
PLATE XLI. 
PAGE. 
WHITELLA RUGATINA, TL. SP .....2. cece cece esse cert eeeneese es ceecasenenescssenses 569 
Left side of a cast of the interior. Middle third of the Trenton shales, Minne- 
apolis, Minnesota. 
WHITELTA CONGENTRIOA WITCH ys). nie secs oesetare ayolnrete eletet setae atetete suet etal mietanetsteteeteeete 569 
The right side and a front view of the type. Middle third of the Trenton shales, 
Minneapolis, Minnesota. 
WHITELLA MEGAMBONA Whitfield, (Spc io- - <2. sis cetrenniniste sien vise scm ct ieiaesis'e nisin) llels 570 
Two views. lateral and anterior, of a good cast of the interior. Trenton lime- 
stone, Minneapolis, Minnesota. 
WHITE A: COMP RESSA JUNILC Hilse cle ore ete ie rate lorete ete etene teistetete elite reeled late ate (ete lenie ta meete terete ate 568 
The right side and a front view of an internal cast, differing slightly from the 
type of the species. 
Two views, side and dorsal, of the original type of the species. Middle third of 
the Trenton shales, Minneapolis, Minnesota. 
WHITELE A TRUNCAITA. UWMiehiseecircr pistes cinitiesate erate teint oral ale ate latevayepnistetcleretsiarcreinreleteleretere 572 
Dorsal, side and front views of an average specimen. 
The right side and a posterior view of the largest cast of the interior seen. 
Galena shales, Goodhue county, Minnesota. 
WEITERE A “PRA CUP TOA MULTI Chet sete cic etetctcle wvetewareieretes stata) pele aerate ekete fete) ole taterak renee lel elt 574 
The left side and a dorsal view of a large and well preserved cast of the interior. 
Galena shales, Goodhue county, Minnesota. 
WHIETEEG AS SCORTE EDT MWC one ec erstoretaimiere sein aicloieys srekniavers statalelsfefarateKe) sf=ture dicta sietete) tales 571 
A very large left valve from the middle third of the Trenton shales at St. Paul, 
Minnesota. 
Hinge of same. The cardinal teeth are abnormally developed. 
Anterior and side views of the original type of the species. Middle third of the 
Trenton shales, Goodhue county, Minnesota. 
Hinge of same x 2, showing the cardinal teeth, the striated escutcheon and the 
posterior internal ligament supports in a very satisfactory manner. 
WHITELLA SUBCARINATA, Dl. SP. e....cccec ct cenccescicecensceecscececebesesionsnce 572 
A well preserved internal cast of a right valve. Middle Galena, Wykoff. Minnesota. 
Cast of a left yalve, supposed to represent an earlier variety of this species. 
Lower Trenton limestone, Jo Daviess county, Illinois. 
WHITELLA VENTRICOSA Hall, Sp...... 2. .ceccecece cece ce renee ceensce cect eccsctcees 573 
Tnternal cast of a right valve in which the anterior margin is uniformly rounded. 
Anterior view of same, with the left valve restored from another specimen. 
Outline of the antero-dorsal part of a left valve in which the anterior margin is 
sharply rounded above. Trenton limestone, Watertown, New York. 
WHITELLA STERLINGENSIS Meek and Worthen ..........---eeeeee eee cree er neces 567 
Antero-cardinal and lateral views of the original type of this species. The speci- 
men is a cast of the exterior. Upper part of the Hudson River group, Sterling, 
Illinois. Dllinois State Museum. 
SAFFORDIA MODESTA Ulrich ........-. 00s esses eee e cece cence eee eee eens ne ee ence: 627 
The left side and a front view of an entire cast of the interior, natural size. 
The specimen is of the average size. Galena shales, Goodhue county, Minnesota. 
The left side of same x 2. 
SAFFORDIA SULCODORSATA Ulrich ........... 2. ccc cence ence ce necsececessccnecas 626 
Antero-cardinal and lateral views of the specimen described. Upper part of the 
Hudson River group, near Spring Valley, Minnesota. 
SAFFORDIA VENTRALIS, 1D. SP. ..eee cess cece c cece cece ces ne scene essseceesenscccecess 626 
Cast of the interior of a left valve. Spring Valley, Minnesota. 
Gutta-percha impression of a natural mold of a small left valve in the base of a 
bryozoan. Hudson River group, Iron Ridge, Wisconsin. 
Anterior view of same. 
Hinge of a right valve. 
A left valve. 
Anterior and cardinal views of same, with the right valve restored from the 
original of figure 37. 
Hinge of the left valve. Upper beds of the Hudson River group, near Spring 
Valley, Minnesota, 
+ 
