Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
Fig. 
Figs. 
Fig. 
Figs. 
Fig. 
Figs. 
Figs. 
Fig. 
6 and 7. 
8 to 14. 
8. 
9 and 10. 
11 to 14. 
15 to 19. 
15 to 17. 
18 and 19. 
20 to 22. 
23 to 26. 
24 to 26. 
28 to 3l. 
33 and 34. 
35. 
36 to 38. 
39 to 44, 
39 to 41. 
43 and 44. 
45, 
PLATE XXXVIII. 
VANUXEMIA DIXONENSIS Meek and Worthen ..............cs-e cece tecere cece cone 
Lateral, anterior and cardinal views of a large cast of the interior. In many 
specimens the anterior sulctis is deeper than in this one. 
View of the interior of a right valve, as shown in a gutta-percha impression. 
A smal! left valve which preserves a portion of the shell. Lower limestone of 
the Trenton formation, Minneapolis, Minnesota. 
VANUXEMEA DIXONENSIS, VATS UNSUETAL, pMlsssVeblyteleieslsstayethis) cle verses etetsreretiet te telecine 
Anterior and lateral views of a perfect cast of the left valve. Trenton limestone, 
Minneapolis, Minnesota. 
WONG op-dunia den <optopenyy. wn 1s FUT 0) 68 Gaon aeonuadsoocb Aeon oSocusaGeonddudcD Soneoond 
Perfect impression of the inner side of a rather large right valve. Geol. Sur. 
Mus. Reg. No. 8319. 
Lateral and antero-cardinal views of an entire cast of the interior. 
Respectively, posterior, anterior, dorsal and side views of the cast of the interior 
of a right valve of a small variety, differing from the usual form of the species 
in the more evenly rounded surface of the casts and greater incurving of the 
beaks. ‘‘Lower Blue” beds of the Trenton formation, Janesville, Wisconsin. 
A Orop.qoniade ores ogiwon tsp DAlaelal ws eon wobadaoboda vee connonaboch agisodecgoanoenres 
Side, anterior and dorsal views of a good cast of the interior. Lower Trenton 
limestone, Minneapolis, Minnesota. 
The hinge and an external view of a specimen retaining a large part of the shell. 
Dixon, Llinois. 
VANE MOEA SUBERECTAS GSD) oi ajeide oaccitoinas phar: aot taltlae pies eee kine eee nace 
Three views, dorsal, side and anterior, of a good, though rather small, cast of the 
interior. Trenton limestone, Beloit, Wisconsin. Geol. Sur. Mus. Reg. No. 8328. 
ASS OPaOLTION Bboy ONS hs Riis rea an godo donde saoodbodeaseoddsoodsa woop sdgupossso.o8 
An internal cast of aright valve. Trenton limestone, Minneapolis, Minnesota. 
Lateral, anterior and cardinal views of a specimen in which the right side is 
preserved as an internal cast, while the other retains some of the shell. 
‘Trenton limestone, Cannon Falls, Minnesota. 
VAIN MTAS CRA SBSIAG SIN; (SP) ois eicislnyaaretataie cis atesaitveigie diers tain, ater orale eels aelsrapepelonmixtoveusteynletetsysteteks 
A sharply defined impression of the inner side of a left valve. Middle third of 
the Trenton shales, Minneapolis, Minnesota. 
VAIN GSMA OMB ONZATBAS GIie? BP) narcisieleeve.s ote ce a atte slatersve cre leteiclevolers be fuicitvend sore eel cVaR Meera 
Four views of right valve of this species. 28, anterior; 29, the hinge; 30, cardinal; 
and 31, lateral. Middle third of the Trenton shales, Minneapolis, Minnesota. 
VANUXEMIA HAYNIANA Safford, sp 
(See also plate xu, and page 479, fig. 36, IV 
») 
A cast of the interior of a small right valve. Galena shales, Kenyon, Minnesota. 
A.ergop-ayy See Wry nes oeny-Uos teu Ol bate Wemndriainos onadccco noosa oda cdoe nod aban donacbe 
Anterior views of the two valves shown in fig. 34. 
Casts of left and right valves of this species. The former was found in the 
Trenton limestone at Minneapolis, and belongs to the collection of the Geo- 
logical Survey, in which it bears the Mus. Reg. No. 5100. The latter is from 
the same horizon at Cannon Falls. 
AP Ueopoonnd Van tow (GRIEG IID \iewinil@lGl, iS\0) pebascenponeugeoancoasbe nooo AdD ocgdoaG- 
The left side of an entire cast of a rather small example. The anterior margin 
seems to be more oblique than usual for this species. Trenton limestone 
(? ‘Upper Buff” beds), Rockton, Illinois. Geol. Sur. Mus. Reg. No. 8325, 
VANUXEMIUA]SUBR ODUINDA MI gS aie ccieicisis ciel ers ala ialel slareitetere e/a ctavereteteteiersiartayetet stalerstate 
The interior of an imperfect right valve. 
External view of a left valve, imperfect in the postero-dorsal region. 
Outline cardinal view of the original of fig. 36. Upper part of middle third of 
the Trenton shales near,Cannon Falls, Minnesota. 
IV-ANTOIXE MIDAS AB RU PTA AN SY) ft foal ecensahe rates aia oveecteueteteianelaiel era isiterei reietistee tet eve eke ale pet mare eee 
Anterior, lateral and dorsal views of a nearly perfect cast of a right, valve. This 
specimen is of the average size and proportions. 
Cast of a large left valve that has suffered slightly from pressure, causing slight 
differences in the outline and the anterior side to be less abrupt than usual. 
Side and dorsal views of a smaller cast of a right valve in which the anterior end 
is very obtuse. Middle Galena, Fillmore county, Minnesota. 
VANUXEMIA (SARDES ONT Wil GH ores olejeis! uit e-ss lotel= aietntnne eleieed relanaketer-cetpiotel ste nieieiecalcierereeisic(s 
(See also plate xxxvu, figs. 17—19.) 
Interior of the left valve as brought out in a gutta-percha impression of the 
original type of the species, 
551 
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553 
553 
553 
556 
557 
556 
560 
559 
560 
555 
