Figs. 
Figs. 
Fig. 
Figs, 
Figs. 
Figs. 
Figs. 
ito 4: 
] 
2to 4 
5 to 10 
5 to 8 
11 
12 to 14 
12 and 13 
14 
15 and 16 
17 and 18 
ily 
PLATE LXXV. 
MACLUREA DERRESSA «0 jan di Siecsesseer eee ee riet irises e nee eee rece ane 
Lateral view of a cast of the interior. Stones River group (Vanuxemia bed), Min- 
neapolis, Minnesota. 
Three views of another cast from Minneapolis. Geological and Natural History 
Survey of Minnesota, Museum Register No. 6868. 
MACLUREA 'BIGSBYI “Hallsxt Mumeede spec eee Ere ee ee 
Four views of a specimen, from the Stones River group at Beloit, Wisconsin, 
somewhat better preserved than usual. A considerable portion of the upper 
side is a cast of the exterior and therefore retains some of the surface mark- 
ings. Geological and Natural History Survey of Minnesota, Museum Register 
No. 73808. 
The outer line represents a transverse section of the outer whorl of the same 
specimen, while the inner lip is a similar section of a specimen of M. nitida U. 
and S. 
A small specimen from Dixon, Illinois, figured for comparison with M. nitida. It 
may be well to point out that the umbilicus is wider and the whorls lower than 
in that species. 
MA OLUREAINTTTDA IU AM Gss «iets isis brcitetele iar jain cia ne retook Rca Ee 
Upper side of one of the largest specimens, showing the rather small umbilicus 
and regular lines of growth. Stones River group, Mineral Point, Wisconsin. 
Geological and Natural History Survey of Minnesota, Museum Register No. 
7356. The inner line of fig. 9 represents the outline of the aperture of this spec- 
imen. 
MACILUREANGR ASS AUS ANG |S seeeteernueee see eines sinc nicacier es tees eee ee 
Upper and lower sides of an entire cast of the interior. The obtuse central angu- 
lation of the whorls is not quite as abrupt in fig. 12 as it should be (see top of 
fig. 14). Trenton group, Lime City, Minnesota. Geological and Natural His- 
tory Survey of Minnesota, Museum Register No. 8442. 
Transverse section of the outer whorl of same. The lower line at the bottom of 
the figure represents the outline of this part of the whorl in a specimen from 
Wykoff, Minnesota. 
MACIUREA GRASSAs Vala MACRA SUL ANG iS ianenanic seit see tiene ee ere necer 
The upper side and a lateral view of the type of this variety. Fusispira bed of 
the Trenton group, Hader, Minnesota. 
HCCYLIOMPHALUS SUBROTUNDUS U. sand) Sante aeeeeeeeeeenenaeee nase aera 5 
Lateral view of a cast of the interior, showing the rounded section of the 
shell and the elevated line near the base of the inner side. Fusispira bed 
of the Trenton group, Wykoff, Minnesota. 
Upper side of same, showing the deep sinus in the upper lip. 
HCCYLIOMPHATUS UNDULATUS Halllsce riser raneeeenn renee ete eee ane een aae 
The lower side of a specimen which retains some of the shell in good condition. 
Stones River group, Lebanon, Tennessee. 
Lateral view of same showing cicatrices where foreign particles had formerly 
been attached. 
Opposite lateral views of an incomplete cast of the interior. Beloit, Wisconsin. 
Transverse section near the mouth of same. 
1039 
1040 
1040 
1040 
1037 
1036 
