12 PROCEEDINGS OF THE NATIONAL MUSEUM vol.78 



two figured specimens has convinced the writers, however, that the 

 forms are inseparable specifically and that they have little in common 

 with Protacanthoceras. The associates oi A.? Jmnabense in Utah in- 

 clude " Helicoceras " pariense Stanton, Baculites gracilis Shumard, 

 Metoicoceras whitei Hyatt (as Buchiceras swallowi Hyatt), and 

 Placenticeras sp.^^ The associates listed by Moreman in Texas in- 

 clude M. whiteiy M. whitei var. (as M. swullowi Shumard), Scaphites 

 aff. warreni M. arid H. (as S. vermiformis Meek), Placenticeras 

 psevdoplacenta Hyatt, Rotnaniceras species (as Acanthoceras species) , 

 Baculites gracilis Shumard, Inoceratnus fragilis Hall and Meek (as 

 /. lahiatus Schlotheim). 



In the material from the Aspen shale a single external mold of 

 the flank of an ammonite shows features so similar to those of Acan- 

 thoceras f kanahense that the writers have little doubt of their being 

 congeneric though specifically distinct. To receive these two species 

 the writers propose the genus Kanabiceras with A.P kanahense Stan- 

 ton as genotype. The following characters may be noted : 



Shell fairly stout; whorls somewhat depressed. Sculpture irregu- 

 lar, coarse, consisting of three rows of small, uneven nodes on the 

 venter, the median row at places forming a rough keel; a row of 

 rather distant, long marginal spines which appear to be hollow at 

 the base and on the internal moulds appear as rounded or truncated, 

 heavy, blunt nodes ; between the marginal nodes faint uneven ribs ; a 

 row of uneven umbilical nodes. The suture only moderately dis- 

 sected, with first lateral saddle narrow, first lateral lobe wide, bifid ; 

 other elements small. 



The described characters of Acanthoceras eschi Solger "*' from the 

 Mungo chalk of Kamerun, Africa, suggest strongly that it also may 

 belong to Kanabiceras, but the writers prefer at this time to make 

 this assignment only tentative. 



KANABICERAS WTOMINGENSE, new species 



Plate 1, Figure 14 



Shell evidently stout-whorled, with relatively small umbilicus — 

 about one-fifth the diameter; umbilical shoulder rounded. Aperture 

 unknown. The type specimen shows a single whorl. There are six 

 or seven blunt irregular nodes near the umbilicus, increasing much 

 in height from the earlier to the later part. There would be 16 mar- 

 ginal nodes, if the complete margin were present, also increasing in 

 height from the earlier to the later part, somewhat irregular, in part 



=5 Stanton, T. W., U. S. Geol. Survey Bull. 106, p. 35. 



=• Solger, Friedrich, Die Fossillen der Mungokreide in Kamerun und ihre goologische 

 Bedeutung, in Esch, Ernst, and others : Beitriige zur Geologie von Kamerun, pt. 2, p. 124, 

 pi. 4, figs. 1-4, text fig. 21, 1904. 



