On a New Genus of Shells from Nebraska. 33 
but interrupted and immense, when the starting point is consid- 
. The physical constitution of man has naturally benefitted 
by it. The details contained in the treatise, of which the pres- 
ent paper forms the introduction, prove that the human race has 
been gradually gaining in vigor and strength since the remotest 
antiquity.* The domestic races also, the dog first, then the 
horse, the ox, the sheep, have shared in this physical develop- 
ment. Even the vegetable soil has been gradually improving 
since the stone-age, at least in Denmark. 
_ And yet there are persons who deny all general progress, see- 
ing everywhere nothing but decay and ruin, like that worthy 
specimen of a northern pessimist, who exclaimed, ‘‘see how man 
is degenerated, he has even lost his likeness to the monkey As 
Art. III.—On a new genus of Patelliform shells from the Cretace- 
ous rocks of Nebraska ;+ by F. B. MEEK and F, V. HAYDEN. 
(With a plate.) 
Genus Anisomyon, M. & H. 
Etym. &oos, unequal; “id, muscle; in allusion to the unsym- 
metrical muscular scar. 
Sometimes nearly central,—immediate apex very small, and ab- 
ruptly curved backwards, but not spiral; interior without a pro- 
Jecting lamina or other appendage. Muscular scar irregularly 
enlarged at the extremities, with the open 
part directed towards the shorter end of the shell; becoming 
cular spots on the right “posterior side ;—anterior extremities 
connected by a slender line, which usually passes across Just in 
front of the summit. 
* This ; : isti 
agrees perfectly with the testimon of statistics. See Quetelet, Sur 
Phomme et le dedigneaiatt de ses facultés. Paris, 1835, ii, 271. This work of 
ts not having : 
Li specimens belong chiatly to the collections brought from Nebraska by 
eut. G. K. Warren, U.$.Top. Eng. Full illustrations and descriptions of the 
SECOND SERIES, Vor. XXIX, No. 85.—JAN., 1860. 
5 % 
