: 
a 
Gow. of 
ge ie = namati a a 
178 Review of Geinitz on the rocks and fossils of Nebraska, 
inence. This obscure furrow, however, is a natural character in 
the H. rugosus, though not always equally well defined, and some- 
times becoming obsolete. Finally it attains a size of from four 
to six times that of the spirorbites. The latter, as shown | 
Prof. Geinitz’s figures in his “ Dyas,” as well as by the specimens, 
varies considerably in some respects, but the American shell is 
very constant and regular in form, and in most of its characters. 
I differ, if possible, still more decidedly from Prof. Geinita, in 
thinking Spirorbis helia of King identical with this; and doubt 
the identity of King’s species with the true S. spirorbites. If our 
shell is identical with any European species, it agrees most nearly 
with the Carboniferous species Huomphalus carbonarius a ol 
(= £. quadratus McCoy, Carb. Foss. Ireland, pl. 5, fig. 22), w . 
—— — nearly resem les, though even these forms are clearly : 
Murchiso sonia subteeniata Geinitz, Carb. und Dyas, pl. 1, fig. 18 
As already eons wiser is a true Orthonema, and will have to take 
the name O. subteniata. 
Bellerophon rie a Portlock. Geinitz, ib. This may or 
may not be identical with Portlock’s species. At any rate it 
—s in the Coal-measures of Kansas. The B. carbonarius, 
‘to the genus s Soleniscus Meck & Worthen (Tilmaois Report 
ii, pl. 81, fig. 15), as it presents Sa the appearance of speck 
mens of the type of that genus with the beak and lower part of 
the 0 outer lip broken away. If the specimen figured has had at 
epression made on the columella sees the fold, it 
may even be the typical species originally described from the 
Coal-measures a Illinois. a 
Allorisma ns King. Geinitz, ib., f 21. If we may jude ae 
from the published figures and descriptions of this species, ie 
can be little room for doubting that the Nebraska shell igure is 
name is a distinct species, even after making liberal 
allowances for variations. If so, it may be called Allorisma? 
initzi, though it seems very doubtful whether it is a true : 
lorisma. It appears to be congeneric with, and allied specifically | 
to, spécionases iat by Dr. S umard from the hort 
el aa 
