854 THE PALEONTOLOGY OF MINNESOTA. 
[Bellerophontiida. 
AMERICAN SPECIES. FOREIGN SPECIES. 
B. leda Hall. Hamilton. B. subdecussata McCoy. Upper Silurian. 
B. lineolata Hall. Hamilton. B. substriata Krause. Upper Silurian. 
B. lyra Hall. Hamilton. B. neglecta Koken. Devonian. 
B. reperta Hall. Hamilton. B. clathrata d’Orbigny. Carboniferous. 
B. rotalinea Hall. Hamilton. B. decussata Fleming. Carboniferous. 
B, textilis Wall. St. Louis. B. elegans W’Orbigny. Carboniferous. 
B. marcouana Geinitz. Upper Coal Meas. B. striata Fleming. Carboniferous. 
?B. elliptica McChesney. Upper Coal Meas. B. textilis De Koninck (not Hall). Carboniferous. 
?B, kansasensis Shumard. Upper Coal Meas. B. angustifasciata Waagen. Permo-Carb. 
’B. meekana Swallow. Upper Coal Meas. B. integra Waagen. Permo-Carb. 
B. kattaensis Waagen. Permo-Carb. 
B. ornatissima Waagen. Permo-Carb. 
The position of the last three species in the list of American species is some- 
what doubtful. They should perhaps be placed with the Bellerophon patulus group 
(Patellostium). 
Parettostium, Waagen (emend.). (Patellostium, Waagen, Phragmostoma, Waagen’ 
[not Hall], Paleontologica Indica, ser. 13, pt. 2, p. 181; 1880.) In this group of 
chiefly Devonian species the characters of the shell may be said to agree in the 
main with Bucanopsis, though this agreement consists chiefly in the fact that both 
have revolving surface lines. Still, even these are not exactly as in Bucanopsis, 
being generally weaker (sometimes very much so) than the transverse lines and 
easily abraded. But the principal peculiarities lie in the greatly expanded aperture 
and the extent to which the inner lip is thickened and reflexed. The callosity is 
sometimes granulose and it may be cut out where it touches the dorsum of the 
preceding whorl, reminding one in both respects of Protowarthia. In our opinion 
these striking forms should be separated from Bellerophon and Bucanopsis. The 
only difficulty is in regard to the name by which the group may be known. Waagen 
distinguished his Patellostium from Phragmostoma upon what, in the absence of 
other differences, we cannot regard as a generic character.* The latter being the 
older name might be employed, only it is well known that what Waagen understood 
under that name is not the same as the original Phragmostoma, which is identical 
with Carinaropsis. Patellostium, on the other hand, is founded upon Roemer’s 
Bellerophon macrostoma, which, unfortunately, is as yet known only from casts of the 
interior. Still, as it is highly probable that Roemer’s species is congeneric with B. 
‘patulus Hall, we would suggest that Patellostium be so amended that it will include 
the following American species: 
Bellerophon newberryi Meek. Upper Helderberg. B. rudis Hall. Hamilton. 
B. natator Hall. Hamilton. B. explanatus Hall. Chemung. 
B. patulus Hall. Hamilton. B. triliratus Hall. Chemung. 
B. montfortanus Norwood & Pratten. Coal Measures. 
* In the first the inner lip is said to be entire, in the other “cut out where it touches the preceding whorl.” 
