PLATE LXXV. 



PAGE. 



Figs. 1 to 4 MACLUBEA DEPRESSA U. and S 1040 



1 Lateral view of a cast of the interior. Stones River group (Vanuxemia bed), Min- 

 neapolis, Minnesota. 



2 to 4 Three views of another cast from Minneapolis. Geological and Natural History 

 Survey of Minnesota, Museum Register No. 6868. 



Figs. 5 to 10 MACLUREA BIGSBYI Hall 1039 



5 to 8 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. 7308. 



9 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. 



10 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. 



Fig. 11 MAOLUREA NITIDA U. and S 1040 



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. 



Figs, 12 to 14 MACLUREA CRASSA U. and S 1040 



12 and 13 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 flg. 12 as it should be (see top of 

 flg. 14). Trenton group. Lime City, Minnesota. Geological and Natural His- 

 tory Survey of Minnesota, Museum Register No. 8442. 



14 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. 



Figs. 15 and 16 MACLUREA CRASSA var. MACRA U. and S : 1040 



The upper side and a lateral view of the type of this variety. Fusispira bed of 

 the Trenton group, Hader, Minnesota. 



Figs. 17 and 18 ECCYLIOMPHALUS SUBROTUNDUS U. and S 1037 



17 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. 



18 Upper side of same, showing the deep sinus in the upper lip. 



FigS. 19 to 23 ECCYLIOMPHALUS UNDULATUS Hall 1036 



19 The lower side of a specimen which retains some of the shell in good condition. 



Stones River group, Lebanon, Tennessee. 



20 Lateral view of same showing cicatrices where foreign particles had formerly 



been attached. 



21 and 22 Opposite lateral views of an incomplete cast of the interior. Beloit, Wisconsin. 

 23 'Transverse section near the mouth of same. 



