J. D. Dana on the Classification of Mammais. 65 
Art. X.—On the higher subdivisions in the Classification of 
Mammals; by James D. Dana. 
or structural expression; and when this expression is appre- 
hended, and its true importance fully admitted, classification will 
alone would suggest the real distinction between the groups, or 
ht that Man was not codrdinal with the Monkeys. In fact, 
nervous system is a very unsafe basis of classification below 
*he highest grade of subdivisions—that into subkingdoms. The 
rr subkingdom may contain species with, and without, a dis- 
di ct nervous system, and a class or order may present very wi 
Yersities as to its form and development,—for the reason, that 
J System or plan of structure in species is far more authorita- 
tive In el 
acteristios of emitey : ti 
eminent importance, separating é 
Mammals But even dene qualities, although admitted to be of 
. This Journal, yo! ; Journal of the Proceed- 
. Xxv, pp. 7, 177, 1858—cited from the 
mgs of the Linnsean Soe, Penton; for Feb. 17 and Ap. 21, 1857. 
Aw. Jour. Sc1.—geconp Serres, Vou. XXXV, No. 103.—Jan., 1868. 
9 
