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JOURNAL OF MAMMALOGY 
the cavern entrance) part of the nest. Within this was a circle of coarse stems 
and leaves of Gutierrezia, inside of which was the nest proper, composed of fine 
plant-fibres and grama grass. The entire nest, sticks and all, was about 2f feet 
long (length extending into the cavern) and 1^ feet wide {across the cavern). The 
part composed of plant fibre and grass was externally 8 inches in diameter, and 
internally (nesting cavity) 6 inches in diameter. The nesting cavity was 3 inches 
deep and entirely open above, evidently in process of construction. 
My stay in this region was limited, so in order to be certain of the identity of 
the little nest-builder a Schuyler rat trap was set on the nest proper. Upon my 
return one-half hour later (5:45 p.m.) a female Neotoma alhigula albigula (No. 
215645, Biological Survey collection, United States National Museum) was in 
the trap. She had moderately developed mammae but contained no embryos. 
— Hartley H. T . Jackson. 
A SECOND RECORD OF PHENACOMYS ALBIPES IN CALIFORNIA, WITH A DISCUSSION 
OF THE SPECIES 
On July 11, 1919, the writer secured a young but apparently breeding female 
of Phenacomys albipes three miles north of Orick, Humboldt County, California, 
which specimen constitutes the second record of the species for the state. It 
was taken in an oat-baited trap under a log-jam near the bank of a stream 
which flows through dense redwood and maple forest. This individual does 
not fully agree with published descriptions, so S. W. Jewett kindly loaned me 
for comparison three specimens of this species from his own collection, and one 
belonging to the Oregon Fish and Game Commission. I was also generously 
permitted to examine the type of albipes, in the collection of the Bureau of Bio- 
logical Survey. Indications point to the fact that most of the cranial differences 
shown by my specimen may be accounted for by its age, which is less than that 
of the others. However, it varies individually in having narrower incisive fora- 
mina with posterior constriction, and a slightly different enamel pattern. 
As the six specimens of P. albipes before me are more than have ever been 
available for study heretofore, it seems desirable to put on record some of the 
average characters of the species as indicated by this series. I find that the 
feet of the type are the palest of any in the lot; they are of a pronounced grayish 
cast, and not pure white as in P. orophilus. The ears of the Orick example are 
covered with black hairs, while in the other five these members are almost naked. 
As with most other microtines, the enamel pattern of the molariform teeth varies 
considerably within certain limits, and one must be careful not to give equal 
weight to all dental differences. The enamel pattern of the upper teeth is rather 
constant in the five skulls of albipes at hand (the sixth is too old, worn, and broken 
to be of much value in this connection). In the case of the lower teeth. Mi of the 
type is unusual in having the outer triangles very irregular in position and size; 
while, in the other four, these are quite uniform. The Orick specimen is pecu- 
liar in having the anterior trefoil of M\ with the outer loop situated entirely 
posterior to the other two. In two specimens there is a tendency for the antero- 
external loop of M2 to open. Normally, in M3 there is a slight constriction in 
the enamel fold near the external end of the middle digitation, but in the Orick 
skull this is developed into a pronounced, though small, outer triangle. 
