118 CARBONIFEROUS AMM0N01D8 OF AMERICA. 



E. Haug" proposes to retain the name, but as a subgenus under Peri- 

 cyclus Mojsisovies, on account of the sharp umbilical lobe. But in i-eality 

 all the Grlvphioceratida? have just such a lobe, only it is usuall)^ on the 

 umliilicus, and the presence of such a lobe is hardly sufficient justification 

 for classing the smooth-shelled Muensterocerasuwdev the roughly sculptured 

 Pericydus. 



The compressed form of this genus seems to indicate its origin in Aga- 

 nides, hv dividing the ventral lobe and widening the umbilicus. 



MUENSTEROCERAS ? HOLMESI Swallow. 



1860. Goniatite^f ]v>hnef<i, G. C. Swallow, Traii.s. St. LouLs Acad. Sci.. Vol. I, 

 p. 659. 



Discoidal, involute, whorls high, al)domen sharply rounded, sides 

 flattened. Whorls deeply embracing, increasing rapidly in height. Umbili- 

 cus narrow, funnel-shaped. Surface smooth, so far as known. Septa 

 unknown. 



Occurrence. — Lower Carboniferous, Kinderhook stage. Cooper County, 



Mo. 



MUENSTEROCEKAS? INDIANENSE Miller. 



PL Y, figs. 3 and 4. 



1891. GoniatiteR Indianeiish. S. A. Miller, Advance sheets Seventeenth Ann. Rept. 



Geol. Surv. Indiana, p. 90, PI. XIX, tig.s. 2 and 3. 



1892. Goniatifes indianemis, S. A. Miller, Seventeenth Ann. Rept. Geol. Surv. 



Indiana, p. 700. PI. XIX. figs. 2 and 3. 



Shell discoidal, involute, deeply embracing, the inside whorl Ijeing 

 entirely concealed by the outer. Whorl highly arched, laterally com- 

 pressed, and indented to one-half of its height by the preceding; sides 

 flattened; abdomen rounded and rather broad. Umbilicus very narrow, 

 not showing the inner whorls. Surface marked by four constrictions that 

 run from the umbilicus nearly straight across the alxlomen. Septa 

 unknown. 



Occurrence. — Lower Carboniferous, Kinderhook stage, Knobstone 

 formation, Clark County, Ind. Type in the State Museum at Indianapolis. 



« Etudes sur les Gouiatites, p. 29". 



