MILLEKOCEHAS. 127 



voutli. The !surface is tree t'roiu scnlptui'c nml (iriKiiiiciitciI onlx' witli lines 

 of growth. 



The septa consist of a ventral lobe, divided 1)}' ;i hroad, notched siphonal 

 saddle, and the i)air of external lobes thus formed are divided a second time 

 by a narrow, spatulate saddle ; a broad, pointed lateral lobe, and another 

 somewhat similar on the umbilical shoulder. Inside the in\(ilutiou there 

 is a long, narrow, tongue-shaped antisiphonal lobe, flanked by a pair of 

 shorter laterals. There are tlnis six external lobes, a pair on the umbilical 

 shoulders, aud three internal, eleven in all. This is the number possessed 

 by I'araler/ocenk^, but in that genus the division of lobes takes place on the 

 dorsal side, inside the umbilicus, while in Bimorphoceras it takes place on 

 the ventral side. 



Dimensions of specimen Jir/Kred. 



Millimeters. 



Diameter 54 



Height of last whorl 32 



Heiglit of last whorl from the preceding 22 



Width of las^t whoil 13 



Involution 10 



Width of umbilicus 3 



This specimen was septate throughout, and if the body chamber added 

 three-fourths of a volution, the complete diameter must have been not less 

 than 100 mm. 



Occurrence. — Upper Coal Measures, Cisco formation, west of Mars Hill, 

 near Graham, Young County, Tex., collected by A. B. Gant. The type is 

 in the private collection of the late Prof Alpheus Hyatt, of Cambridge, 

 Mass., to whose kindness the writer owes the use of the specimen. 



Genus Milleroceras ? Hyatt. 

 ]\IiLLEROCERAS PARRiSHi Miller and Gurley. 



PI. XVI, figs. 6-8. 



1894-. Goniatitea wp. indet., C. K. Keyes, Geol. Survey Mi.ssouri, Vol. V, Pt. VII, 



PL LV, tig. 1. 

 1896. Goniatit&i parrlshl, Miller and Gurley. Bull. Illinois .State Mus. Nat. Hi.st. 



No. 11, p. 36, PI. IV, figs. 6-8. 

 1900. Millerocerm pai-rhhi. A. Hyatt, Cephalopoda, 1900. p. .5.50. 



This species is the type of Hyatt's supposedly new genus Milleroceras, 

 which he assigned to the Primordialida\ The writer has examined the 

 tv]>e, in the paleontologic collection of the University of Chicago, and is con- 



