370 T. Gill on the genus Elasmognathus. 
ogies) to the genera Trochus, Bulimus and Phasianella: such ex- 
treme cases are not rare in Paleontological literature, and, to 
say the least, are suggestive of a confusion of ideas which neces- 
sarily renders our confidence in the describers very limited. 
Let us hope that such errors will be more generally avoided here- 
after, and that, with such bases as we have in the publications un- 
der review, worthy superstructures may be erected, and that the 
good examples set therein may be followed by at least our own 
countrymen, T. G. 
: Art. XLIL—On the genus Elasmognathus ; by THEODORE GILL. 
SINCE my communication on the new Tapiroid to which I 
have given the name Hlasmognathus Bairdii, I have been enabled 
to examine skulls of four more specimens of the species, all essen- 
tially agreeing, but offering differences which perhaps indicate 
sexual variation. The more the skull is examined, the more does 
the great difference from the other Zapiride impress the observer; 
it resembles that of the Asiatic Tapir (Rhinocherus Malayanus) 
rather than those of the American species (Tapirus terrestris, T. 
pinchaque), especially in the abbreviation of the cranial box, and 
apparently in the form of the maxillary bones behind, as well 
as of the nasal bones. The abbreviation of the cranial box is a 
vey important peculiarity of the new type and contrasts strongly 
with the larger one (not only relatively but actually) of Zapi- 
rus; this abbreviation would seem to entail some of the differen- 
ones, and the complete osseous mal gaye of the nasal septum, 
mals, none oe ei ag tichorhinus has a nasal septum so 
completely ossified as Hlasmognathus. 
