854 THE PALEONTOLOGY OF MINNESOTA. 



LBelleropbontiuhB . 



AMERICAN SPECIES. FOREIGN SPECIES. 



B. leda Hall. Hamilton. B. subdeciissata McCoy. Upper Silurian. 



B. lineolata Hall. Hamilton. B. sitbsstriata Krause. Upper Silurian. 



B. lyra Hall. Hamilton. B. negkcta Koken. Devonian. 



B. reperta Hall. Hamilton. B. clathrata d'Orbigny. Carboniferous. 



B. rotalinea Hall. Hamilton. B. decutsata Fleming. Carboniferous. 



B. textilis Hall. St. Louis. B. ekgans d'Orbigny. Carboniferous. 



B. marcouana Qeinitz. 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. tmgustifasciata Waagen. Permo-Carb. 



IB. meekana Swallow. Upper Coal Meas. B. intcgra Waagen. Permo-Carb. 



B. kattaensds 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). 



PATELLOSTIUM, Waagen (emend.). (Patellostium, Waagen, Phragmostoma, Waagen 

 [not Hall], Paleontologica Indica, ser. 13, pt. 2, p. 131; 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. trilirutus Hall. Chemung. 



B. monlfortamts Norwood & Pratten. Coal Measures. 



* In Die first the Inner Up is s:M to be entire. In the othi-r "rut out when' it louche- th pnvi-dinK whorl." 



