PLATE LXTV. 



PAGE. 



Figs. 1 to 5 BELLEROPHON TROOSTI (D'Orbigny) Safford 915 



1 to 3 Three views of a nearly entire example from the Trenton group near Nashville, 



Tennessee. 

 4 and 5 Two views of a specimen from Danville, Kentucky. 



Fig. 6 BELLEROPHON TROOSTI var. BURGINENSIS Ulrich 916 



Lateral view showing larger umbilicus and lesser reflection of the lower part of 

 the lip than occurs in typical B. troosti. Trenton group, Burgin, Kentucky. 



Figs. 7 to 10 BELLEROPHON CLAUSUS Ulrich 916 



7 and 8 Apertural and lateral views of a silicifled shell showing the closed umbilici, 

 strongly reflected and deeply excavated lower lip, the lunulas on the slit-band, 

 sharp and subequal transverse markings, and other peculiarities of the species 

 when compared with B. troosti. Trenton group, middle Tennessee. 

 9 Dorsal view of a smaller specimen from the Trenton at Frankfort, Kentucky. 



10 Portion of the back of the Tennessee specimen, x2. 



Figs. 11 to 13 BELLEROPHON RECURVUS Ulrich 920 



11 Dorsal view of a small specimen, probably of this species. 



12 and 13 Lateral and dorsal views of the type, showing the marked backward sweep of the 

 lines of growth on the back, with a rounded dorsal ridge as in B. troosti, and 

 the lip reflected over and completely closing the umbilicus as in B. clausus. . 

 Lorraine group, Cincinnati, Ohio. 



Figs. 14 to 16 BELLEROPHON SUBANGULARIS Ulrich 920 



Three views of a specimen preserving much of the shell and surface markings. In 

 figure 14 the mouth is turned forward a little more than usual to show the bight 

 of the dorsal carina. Kichmond, Indiana. 



Figs. 17 and 18 BELLEROPHON SUBGLOBULUS Ulrich 917 



Dorsal and lateral views of a silicifled shell. Black Eiver group, Mercer county, 

 Kentucky. 



Figs. 19 to 21 BELLEROPHON BILINEATUS Ulrich 917 



Three views of a silicifled shell showing, of features characterizing the species, 

 the open umbilicus and the concave slit-band' with its distinctly elevated bor- 

 dering lines. Upper part of Trenton group, Danville, Kentucky. 



Figs. 22 to 30 BELLEROPHON PLATYSTOMA Meek and Worthen 918 



22 and 23 Dorsal and lateral views of a small cast of the interior with the lateral expansions 

 of the aperture broken away. Fusispira bed of the Trenton group, Cannon 

 Falls, Minnesota. 



24 and 25 Two views of a similarly imperfect cast. This specimen was received from Prof. 

 Worthen, who collected it frcm the Trenton (Ga'ena) limestone at Dixon, 

 Illinois 



26 An Imperfect cast of the exterior preserving some of the surface markings. Cli- 

 tambonites bed, Trenton group, Goodhue county, Minnesota. Geological and 

 Natural History Survey of Minnesota, Museum Register No. 6765. The dorsal 

 keel Is quite prominent in this specimen and the slopes on each side distinctly 

 concave. 



27 to 29 Three views of another specimen, from the same horizon as the preceding, 

 retaining part of one side of the outer lip. 



30 Transverse section of whorl of original of figure 25, the inner line corresponds 



to the point marked "S" on that figure, the outer represents the section just 

 within "the apertural slit. 

 Figs. 31 to 39 BELLEROPHON SIMILIS U. and S 919 



31 Transverse section of whorl. Compare with figure 30. 



32 and 33 Lateral and basal views of two small imperfect casts of the exterior, showing dis- 

 tinct impressions of the external lines of growth. Fusispira bed, Trenton group, 

 Cannon Falls and Wykoff, Minnesota. 



34 to 36 Three views of a nearly perfect and large cast of the interior; from the same 

 locality. 



37 Dorsal view of another large specimen from the locality last mentioned. On 



the outer parts of this specimen the regular lines of growth are quite distinct, 

 while on the leftside several broad longitudinal folds are somewhat obscurely 

 visible. 



38 Part of the dorsura of another specimen showing the prominent dorsal ridge and 



the lines of growth curving backward to It. 



39 View of the aperture of a small example retaining a portion of the inner lip. 



Clitambonites bed, Trenton group, Cannon Falls, Minnesota. 

 Figs. 40 to 43 BELLEROPHON CAPAX Ulrich 921 



(See also plate LXIII.) 



40 and 41 Two views of a large cast of the interior, imperfect at the aperture. Lorraine 

 group, Covington, Kentucky. 



42 Lateral view of a smaller cast from the same locality. 



43 Transverse section of whorl of this and the following species. The sections are 



taken from casts of the interior, the inner line representing the ventral side of 

 the whorl in B. mohri, the lower that of B. capax. As shown by the outlines, 

 the surface descends into the umbilicus much more abruptly in the former than 

 in the latter. 

 Figs. 44 and 45 BELLEKOPHON MOHRI Miller 920 



44 Lateral view of a large cast, imperfect at the aperture. Richmond, Indiana. 



(Compare with figures 41 and 42, and refer to explanation of figure 43.) 



45 Apertural view of a testiferous example for comparison with figure 51 on plate 



LXIII. 



Figs. 46 to 49 KOKENIA OOSTALI8 U. and S 882 



46 and 47 Lateral and dorsal views, the inner whorls restored, of the type of this genus and 

 species. Clitambonites bed, Trenton group, Gannon Falls, Minnesota. 



48 Transverse sections of the last whorl. The lower side of the figure is the dorsal. 



49 Portion of the broad dorsal band and of the right slope, x3. 



