Ifollis^fe'i—Four Nnv A^entropira] Fodcitl^. . '>0 
Characters. — Skull It'ss lieavily built than in IIiidrocluvrus Iiiidrochicris 
hj/drocluvris from Suriuaiu ; maxillary arm of zyjfoma much more Hlendcr, 
less imiHsivo; occi])ut sliorbaied, actually and relatively much less (don- 
gated; presi)henoid narrow and tapering anteriorly; lachrymal hone, 
lateral as{)ect, much higher than wide, extending far downward to sharj) 
point [in hi/drochivris wider than high and not sharply pointed on lower 
side] ; jaw much lighter, lower posteriorly, and with inferior surface of 
angle much flattened; synpdiysis sliorter; su})erior notch long and shallow 
[in hydroclunds shorter, much deeper, and m(W(' rounded]. Upper in¬ 
cisors smaller than in hydroclurris; cheek teeth smaller, the last uj)per 
molar especdally much narrower; vC with double anterior lobe, ten trans- 
ver.se enamel plates [in hydroclueris nine] and posterior hooked lobe. 
Measuronents of typ(' skull, compared with a very slightly older skull 
from Surinam (U. S. X. M. IdOOT), measurements of latter in ])aren- 
theses: Greatest length, 287 (252); condylohasal length, 225 (228); zygo¬ 
matic breadth, 120 (H:)); palatal length, 145 ( 150); coronal suture to 
occipital crest, 57 (00); height of lachrymal, 2)7.5 (21). Teeth: Single 
upper incisor at middle, 8.8 x 11.0 (0.7 x 12.2); maxillary tooth row% 
alveoli, 75.8 (70.8); greatest breadth of nv\ 18.0 (16). 
Remarks. —This form is based on four specimens fnjm Paraguay, all 
of which agree in the presence of the characters given above to distin¬ 
guish the southern animal from the capyhara of Surinam. The differ¬ 
ences between skulls from the two regions are so jwonounced, that were 
it not for tw(j skulls in tlie collection from Brazil, which certainly show 
some intermediate characters, the specific distinctness of the two forms 
would never he cpiestioned. 
