No.i24r,. MAM}rALS OF VEXEZUELA— ROBINSON AND LYON. 143 
dorsal area. The raw sienna is more extensive on the lateral dorsal 
regions and on the sides; as it approaches the belly it bleaches out to 
buff in color. Upper surfaces of the legs grayish. Dorsal surface of 
tVet covered with a few short whitish hairs. Entire under parts, 
including region about mouth and under surfaces of legs, light gray. 
Fur everywhere slate color at base. Tail brownish throughout, darker 
above and at the tip, lighter beneath; clothed with a few tine short 
dark hairs about three to a scale, and in length equal to about a scale's 
length and a half. Ears brownish, clothed inside and out with a few 
short tine dark hairs, more numerous and darker externally. 
An old adult nursing female has a greater predominence of the raw 
sienna. This color is lirighter than in the tj-pe and approaches tawn}^ 
ochraceous. The hairs of the under parts are much worn and almost 
slate gray. 
Jfeasure// tents. — Type: Total length, 262; tail, 138; hind foot, 31; ear 
from meatus (measured on the dr}^ skin), IT. Average of four speci- 
mens, length, 260; tail, 134; hind foot, 31. 
Shf/l. — Intermediate in size between that of Oryzomys nioUip'dosxis 
and 0. magdaluim, but similar in shape to that of former. The inter- 
orbital region is narrowed and the temporal beading well developed, 
as in (K nioJIipiJoKus^ but the brain case is broader behind and the 
upper tooth row longer by half the last molar. Palate wider between 
the mohii's. Comparing the skull of Oryzoryiys m.ediiis with that of O. 
niagdal/mw it is seen to be narrower interorbitally, the beading more 
convergent, so that if prolonged forward the lines would meet at the 
posterior end of the nasals. In O. magdalbuB they would meet at 
middle of nasals. The l)rain case of O. medius is more expanded, the 
rostrum shorter. The upper tooth rows are of the same length in each, 
but the teeth are wider in 0. medius than in 0. magdalincB. 
Measurements of the t3^pe skull: Total length, 30.4; basal length, 
25; zj^gomatic width, 14.2; mastoid width, 11; least interorbital width, 
5; length of nasals, 12; palatal length, 6.4; length of palatal foramina, 4; 
length of upper tooth row, 4.6; greatest length of lower jaw, 17.6; 
depth of lower jaw at condyle, 7.2; length of lower tooth row, 5. 
Oryzomys rnedhis is based on four specimens, a fully adult female 
and three young adailt males, measurements of which are given below. 
As alreadv mentioned, it is intermediate between and at the same time 
entireU" distinct from 0. moUijpilosus and O. magdaUnce. The color 
of the old female is almost precisely the same as that of O. inagdalinoe., 
but 0. inollljj'dosus is a lighter colored animal. In the structure of the 
skull, however, 0. medius and O. inollip'dosus are remarkabl}' alike. 
Three specimens were taken at San Julian under some vines and 
stones around a dead stump on the edge of a coffee plantation. They 
were captured in cyclone traps baited with rolled oats. A fourth 
specimen was taken at Macuto. 
