Figs. land 2 
3 to 
3 and 
Figs. 9 
4 
5and 6 
7 
8 
9 
10 to 18 
Figs. 
10 and 11 
12 
13 and 14 
15 
16 
17 
18 
Figs. 19 to 238 
19 and 20 
21 to 23 
Figs. 24 and 25 
24 
25 
Figs. 26 to 29 
26 
27 
28 
29 
Fig. 30 
Figs. 31 to 37 
31 and 32 
36 
37 
Figs. 38 to 40 
38 and 39 
40 
Figs. 41 to 44 
PLATE LXV. 
TET RANOTASMAG RAMU: (ATG GS )to\c a1 nieic\elels ote 2 cieleteleisicin ee (ole <leqaieis oleic sien eee ee eee 
Dorsal and lateral views of the type of this species. Stones River group, Minne- 
apolis, Minnesota. The specimen is a good cast of the interior and shows the 
expanded mouth, the peculiarly lean appearance and strongly ribbed charac- 
ter of the fossil. 
TDR AN OUAY SEEN CUATRINA IMA! TU) SicvI 4S ppeeaetate evel tepstere tata tete etal cneteletcieke inte opelintateleetetstete Iatele orator 
Two views of an excellent specimen from the Fusispira bed at Wykoff, Minne- 
sota. Though a cast of the interior, the surface markings are clearly indicated. 
Dorsal and lateral views of a cast of an early variety of the species. Stones River 
group, Minneapolis, Minnesota. 
Sectional view of preceding specimen. 
Section of a whor! of a specimen from the Stones River group, at Dixon, [llinois. 
Section of whorl of Wykoff specimen. 
TETRANOTA BIDORS ATA HAL] ESD: mina eercorclele a ere eel teks tetra fe nietaie le etree eiele sitter eters 
Two views of a large cast from the lower part of the Fusispira bed near Cannon 
Eels Fees rcs This specimen evidently has been somewhat compressed 
aterally. 
Another cast tilted forward slightly to show the hight of the central ridge. 
Clitambonites bed, Goodhue county, Minnesota. Geological and Natural His- 
tory Survey of Minnesota, Museum Register, No. 7382. 
see views of aspecimen with the apertural parts broken away. Clitambonites 
ed. 
Another specimen from the Clitambonites bed preserving the apertural margin 
with some of the surface markings on one side. 
Surface markings of same, x3 and x5. 
Ventral side of fragment of outer volution showing transverse section of same 
below and four grooves produced by the dorsal ridges of the preceding whorl. 
Clitambonites bed. 
Dorsal view of a small specimen. The majority of the specimens seen from 
the Clitambonites bed range in size between this and figure 13. 
PRTRANOTA: -OBSOLETA JU ANOS het cirs te ciaeis vem frit tee eeieineine eceiseine ie areein ieteretee 
Dorsal and apertural views of a testiferous example on which the slit-band has 
remained concave throughout the growth of the shell. Ctenodonta bed, Chat- 
fleld, Minnesota. 
Three views of the specimen which we regard as the type of the species. Though 
retaining the shell, we have failed to discover any remains of surface markings. 
Ctenodonta bed, Goodhue county, Minnesota. 
TETRANODA, SP. WO G6ti. sir s..ts crease yi ate, casio als sje ein ciola eyelet ue shale aietere/eNehawitcltorkeb ants 
Dorsal view of a good cast of the interior from the Utica group at Cincinnati, 
Ohio. This specimen may represent a later variety of T. bidorvsata Hall, but in 
the obsolesence of the latero-dorsal ridges, as may be seen from the basal out- 
line, it agrees more closely with TZ. obsoleta. 
Dorsal view of a cast of the interior of an undescribed species of this genus. 
Stones River group, Minneapolis, Minnesota. The ridges in this species, of 
which our material is not sufficient to warrant us in giving it a name, are 
unusually obscure. 
TETRANOTA WISCONSINENSIS Whitfield sp.......02:s2seceseccccsseecsceuceescteres 
Dorsal view of a large and nearly perfect cast of the interior. Stones River group, 
Beloit, Wisconsin. Collection, University of Wisconsin. 
View of same with the smaller volutions removed, showing the ventral side of 
the outer whorl with the four furrows which are always found here in species 
of Tetranota. 
Lateral view of same. 
Dorsal view of a very small specimen supposed to be the young of this species. 
Minneapolis, Minnesota. 
SfonsavAon force e unob-ewnctsh LOphnOlereos cobu cae cosontabobadedesosas 
A specimen showing the slit in the outer lip and preserving some of the delicate 
surface markings. The enlargement of the latter (x2) represents part of the 
upper third of the last whorl to the suture line and above this the slit-band of 
the preceding whorl. Upper part of Trenton group, Nashville, Tennessee. 
SCHIZOLOPEHA. MGORET WUTC Nict ieteerejece stele tisiete sie tse fosin Se re sineiem ce eieinieeseieterere ace ie eleineie 
Two views of anearly perfect cast of the interior of the typical form of this species 
showing the slit, the great prominence of the carina on the last whorl, the 
au and other characteristic features. Richmond group, Richmond, 
ndiana. 
Gutta percha impression from a natural mold of the exterior, showing the coarse 
surface markings. Richmond, Indiana. i 
Outer third of the last whorl of a specimen overgrown by a species of Protarea, 
which originally covered all of the exterior of the shell excepting the slit in the 
aperture. Locality, same as preceding. 
Transverse section of the last whorl of a cast from the same horizon and locality. 
The small indentation on the umbilical side (left side of figure) is characteristic 
for the typical form of the species. 
Transverse section of the last whorl of a small variety occurring in the Lorraine 
group at Cincinnati, Ohio. In casts of this form the peripheral angle is less 
prominent than in the typical form, and there is no indentation on the umbil- 
ical side. (Compare with figure 35.) 
Vertical section of an unusually high, testiferous example of the Cincinnati 
variety. 
TLOPHOSPIRA (2), KNOX VILLENSIS (UITICH a. ccsctejsice oy avaleeveleaieustetereue te erelnielslareyei tole syetsteteirete 
Umbilical and apertural views of a specimen showing the general form of the 
shell, which is much as in Zrochonema, with the distinct peripheral band of a 
Lophospira. (Knoxville, Tennessee. (? Chazy group.) 
View of the umbilical side of another specimen from the same locality. 
LOPHOSPIRA ? TROCHONEMOIDES Ulrich .............. stavarcial svete seisiole atteie risrolois'«¥is' ass 
Four views of the type of this species. 
878 
877 
880 
880 
881 
992 
992 
989 
