424 THE AMERICAN NATURALIST. (Vor. XXXIX. 
horned dinosaurs (Ceratopsia) always exhibit. Another feature 
which is indicated in the figure is that the summit of each main 
prominence as well as those of the lesser secondary ones are 
curiously rugose resembling, though the ruga are coarser, the 
roughened patches beneath the horns of the rhinoceros. 
Thus one is led to doubt the probability of a horny sheath 
covering the entire prominence, yet the very mobility of the 
neck and the strength of the head-wielding muscles indicate 
the presence of an efficient armament of a size commensurate 
with the strength of its support. This together with the rugos- 
ities seems to point to the existence of horns formed, as in the 
rhinoceros, of agglutinated hair-like fibers; a larger pair upon 
the summits of the main, and, in this species, a lesser pair upon 
the secondary prominences. 
This conception perhaps renders the creature somewhat more 
grotesque, but it would surely provide him with offensive and 
defensive weapons which with his evident prowess would make 
the titanothere peerless among the creatures of his time. 
AMHERST, Mass. 
