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INo. 38 

[Actual date of publication, April 17, 1909] 


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Prepared under the direction of 








No. 28 

[Actual date of publication, April 17, 1900] 




Prepared under the direction of 



19 9 


aur< ur uutu*itNiJ>. 


U. S. Department of Agriculture, 

P ological Survey, 
Washington, D. C, -Inly 16, 1908. 
Sir : I have the honor to transmit for publication as North Ameri- 
can Fauna Xo. 28 a revision of the mice of the American genus 
Peromyscus, by Wilfred H. Osgood. Tl work consists of a system- 
atic study of all the members of the gem s, and includes keys for the 
identification of the various forms, together with the necessary illus- 
ations, and maps showing the geographic distribution of the species. 
The mice of this group occur in great abundance throughout the 
r nited States, particularly in the Western States, but up to the present 
ume the interrelations and ranges of the various forms have not been 
worked out. Lack of this knowledge has been a source of embarrass- 
ment to workers in many parts of the country, particularly to the 
Biological Survey in its investigations of the geographic distri- 
bution and economic relations of American mammals. It is impor- 
nt, therefore, that a revision of the group be made available for 
general use. 

Respectfully, C. Hart Merriam, 

, Chief, Biological Survey. 

Hon. James Wilson, 

Secretary of Agriculture. 



Introduction 9 

Material 10 

History and nomenclature 11 

Variation 14 

Intergradation 17 

Pelages 19 

Color descriptions 21 

Measurements 22 

Keys 23 

Records of specimens 23 

Subgenera 24 

Habits and economic status 26 

List of species and subspecies with type localities 28 

New subspecies 32 

Genus Peromyscus 32 

Subgenus Peromyscus 33 

Subgenus Megadontomys 218 

Subgenus Oehrotomys 222 

Subgenus Podomys 226 

Subgenus Haplomylomys 228 

Subgenus Baiomys _ 252 

Tables of measurements 260 

Index 281 



Plate I. Distribution of the species and subspecies of the Peromyscus manicu- 

latus group Frontispiece. 

II. Skulls (dorsal views) of Peromyscus maniculatus, P. m. arclicus, P. m. 
austerus, P. ///. hylseus, P. m. gracilis, J', m. hollisteri, P. sithensis, 
P. in. keeni, P. m. pallescens, P. m. bairdi, P. polionotus, and P. m. 
gambeli 2»><s 

III. Skulls (dorsal views) of Peromyscus leucopus tornillo, P. gossypinus, 

P. I. cozumelse, P. I. mesomelas, P. oaxacensis, P. lophurus, P. simu- 
latus, P. hylocetes, P. crinitus, P. c. stephensi, P. eremicus, and P. I. 
texanus -- 270 

IV. Skulls (dorsal views) of Peromyscus boylei, P. I>. levipes, P. b. spid- 

legus, P. b. simulus, P. l>. aztecus, P. truer, P. per/oral is eremicoides, 

P. nasutus, P.t. gratus, P.taylori, P. museums, and P. lepturus 272 

V. Skulls (dorsal views) of Peromyscus banderanus, P. guatemalensis, 
/'. melanophrys, P. yucatanicus, P. megalops, P. difficilis, P. furvus, 
P. mexicanus, and (lateral views) /'. /. noveboracensis, P. musculus, 

P. nuttalli, P. eremicus, P. thomasi, and P. floridanus 274 

VI. Skulls (dorsal views ) of Peromyscus zarhynchus, P. flu villus, P. thomasi, 
P. leucopus, P. californicus, P. floridanus, and P. nuttalli. Jaws of 
Peromyscus nuttalli, I', floridanus, P. californicus, P. I. noveboracensis, 
P. flavidus, P. I. noveboracensis, P. eremicus, J', thomasi, and J'. 

in usculus 276 

VII. Skulls (ventral views) of Peromyscus floridanus, P. nuttalli, P. I. 
imreboracensis, P. eremicus, P. thomasi, P. mexicanus, P. bullatus, 

P. flavidus, P. boylei, P. truei, P. musculus, and P. m. gracilis 278 

VIII. Upper molars (in profile) of Peromyscus thomasi, P. I. noveboracensis, 
and P. /. eremicus. Upper molars (worn crowns) of P. thomasi, 
P. californicus, P. nuttalli, and P. /. noveboracensis. Lower molars 
(worn crowns) of P. thomasi, P. I. noveboracensis, P. m. gracilis, 
P. m usculus, and P. floridanus 280 


Fig. 1 . Distribution of Peromyscus melanotis 110 

2. Distribution of Peromyscus leucopus and subspecies 11-1 

3. Distribution of Peromyscus gossypinus and subspecies 136 

4. Distribution of Peromyscus boylei and subspecies 143 

5. Distribution of Peromyscus pectoralis, P. megalops, P. furvus, and P. gua- 

ternalensis 161 

6. Distribution of Peromyscus truei and subspecies 166 

7. Distribution of Peroinyscus difficilis and subspecies 179 

8. Distribution of Peromyscus melanoplirys and subspecies 184 

9. Distribution of Peromyscus nuttalli and P. n. aureolus 224 

10. Distribution of Peromyscus crinitus and subspecies 230 

• 11. Distribution of Peromyscus eremicus and subspecies 240 

12. Distribution of the subgenus Baiomys 253 

No. 28. NORTH AMERICAN FAUNA. April, 1909. 



By Wilfred H. Osgood. 


The American rodent genus Peromyscus, including the so-called 
wood mice, deer mice, vesper mice, or .white-footed mice, has needed 
revision for many years. One or more of its numerous species and 
subspecies inhabit almost every part of North America ; moreover, 
these mice, wherever found, are among the most abundant of small 
mammals. The group, therefore, is of such importance that it must 
be dealt with in every work on North American mammals, whether 
pertaining to classification, geographic distribution, or economic 

Although the amount of material examined for the present work 
is very large and the opportunities for study have been exceptional, 
not all the conclusions can be claimed to be final. However, the 
material in most cases has amply sufficed to demonstrate purely 
zoological problems; the chief difficulty has been to bring within the 
sharply defined limits of nomenclature and classification natural ob- 
jects which are not sharply limited. In the study of such a large and 
widely ranging genus nearly all the moot points of modern systematic 
zoology are encountered. Most of these have been treated conserva- 
tively. Misidentifications, even of decidedly distinct species, hitherto 
have been the rule rather than the exception. Therefore, very fine 
discrimination at this time would not conduce to a general under- 
standing of the group, but would tend rather to confusion. The re- 
viser's own idea of the term '"conservative" is of course subject to 
the interpretation of other workers. Describers of slight local or 
intermediate forms, who find many of their names in synonymy, will 
doubtless consider the treatment too conservative, while others, noting 
the long array of subspecies admitted, may think it too radical. 



Important but not strictly taxonomic problems have appeared in 
almost every group; but most of these, however interesting, have been 
regarded as beyond the scope of the work. They relate especially to 
details of distribution, variation, evolution, and various questions 
which can best be treated by special workers with ample time, special 
data, and limited general obligations. Students of local faunas will 
find in these problems opportunities for extremely interesting and 
valuable work 


In 1891, Dr. J. A. Allen, after discussing certain species of Pero- 
myscus, made the following statement:" 

Bui the time has not yet come for ;i satisfactory revision of the group, to 
attempt which at least 20,000 specimens are requisite, collected so as to 
fully represent the seasonal phases of pelage obtaining at hundreds of more 
or less widely separated localities. 

These conditions are now realized to the fullest decree, for the 
number of specimens examined in the present revision exceeds 27,000. 
The majority of these are contained in the extensive collection of 
the Biological Survey, which", under the direction of Dr. C. Hart 
Merriam, has been built up with special reference to the various life 
areas of North America, and without which no satisfactory study 
of this group would now be possible.'' In addition, all the material 
in the more important public and private collections of America 
has been examined, and also important specimens belonging to Euro- 
pean institutions, especially the British Museum. This . material 
includes all the types, both of valid forms and of synonyms, known 
to be in existence. In almost all cases in which no types exist, good 
series of topotypes, or specimens from near the type localities, have 
been available. The American collections which have been thoroughly 
examined are distributed as follows: Biological Survey (including 
the collection of C. Hart Merriam, on deposit); U. S. National 
Museum; American Museum of Natural History. New York: Field 
Museum of Natural History. Chicago; Museum of Comparative 
Zoology. Cambridge (now including the collection of E. A. and O. 
Bangs) : and the Academy of Natural Sciences. Philadelphia (now 
including the collection of S. N. Rhoads). The individuals having 
charge of these collections have generously allowed the unrestricted 
use of their material. Special acknowledgments are due Dr. J. A. 
Allen, of New York: Mr. Outram Bangs, of Boston: Dr. F. W. True. 
Mr. Gerrit S. Miller, jr.. and Dr. M. W. Lyon, jr., of Washington; 
Mr. Witmer Stone, of Philadelphia ; and Drs. D. G. Elliot and S. E. 

"Bull. Am. Mus. Nat. Hist. Ill, p. 307, 1891. 

6 Unless otherwise stated, specimens mentioned by number in the body of 

this report are in the Biological Survey Collection. 


Meek, of Chicago. It is also proper to acknowledge the assistance of 
various members of the staff of the Biological Survey who have aided 
greatly by their knowledge of local conditions, especially Vernon 
Bailey. E. W. Nelson, E. A. Goldman, and E. A. Preble. Occasional 
specimens from small institutions or private collectors in various 
parts of the country have been examined, and mention of these has 
been made in the systematic part of the work. 


Early authors, noticing only its superficial resemblance to the 
European wood mouse (Mus sylvaticus), placed the deer mouse of 
Eastern North America in the genus Mus, and for some years nearly 
all American murines were included in that genus. In 1839, Water- 
house" drew attention to the dental characters that distinguish Amer- 
ican cricetines from the genus Mus, and. chiefly on the basis of studies 
of South American forms, proposed the name Hesperomys to include 
all American rodents having a biserial arrangement of the molar 
tubercles. This name, although proposed in an irregular way (being 
antedated by its own subgenera), immediately became current and 
besides being used for various South American rodents, was pressed 
into service for the North American cricetines. It then comprised a 
large number of subgenera, most of which are now recognized as 
genera, as Oryzomys, Onychomys, Eligmodontia, Oxmycterus, I'hyl- 
lotis, and others, and was used as late as 1891. when Allen '' argued 
that, since it could not be restricted to any particular type, its use 
should be discontinued. Meanwhile some authors (as Audubon and 
Bachman 1851-1851) failed to recognize the distinctions of Water- 
house, and continued to use the generic name Mus. Previous to 
Allen, however. Jordan had displaced Hesperomys and adopted 
Calomys, apparently assuming (not unreasonably) that Mus bimae- 
ulatus, which formed the chief basis of Waterhouse's characteriza- 
tion of Hes])eromys, was its type, and that this species being also the 
type of the earlier Calomys, would make the two names absolutely 
identical in application, thus forcing the use of Calomys because 
of its priority. This action of Jordan was quite in conformity 
with a statement of the case made by Coues in 1877/ 7 But Cones. 
although his own statement showed Hesperomys invalid, still re- 
tained it, apparently on the ground that it was " firmly established, 
and as the prior name Calomys is by the same author." However, 
he confined its use " in its strictest subgeneric sense " to South Ameri- 

" Zooi. Voy. Beagle, p. 7.".. is.39. 

"Bull Am. Mus. Nat. Hist.. III. pp. 291 l".)4. .Tune. 1891. 
''Manual. of Vertebrates, nth ed., p. 321. 1888. 
*Monojgr. N. Am. Rodent., pp. 43-14. 1877. 


can forms, and for the reception of the North American forms 
adopted the subgeneric name Vesperimus previously proposed by 
him with the Mus leucopus of- authors as type. When, therefore, in 
1801, Allen discarded Hesperomys entirely, he adopted Coues's Ves- 
perimus for the northern group of cricetines. The currency of Ves- 
perimus was brief, for in 1892, Merriam a showed it to be antedated 
by Sitomys Fitzinger, 18G7. This was thereupon adopted and used 
until L894, when Thomas 6 discovered a still earlier claimant, Pero- 
myscus Grloger, 1841. This name has remained unchallenged for 
nearly fifteen years, and it is to be hoped w r ill never be supplanted. 

In the first pretentious work on the mammals of North America, 
that of Audubon and Bachman (1851-1854), only 3 species of those 
now T recognized as belonging to Peromyscus were included, namely, 
aureolus, leucopus, and michiganensis (=bairdi) . Previous to 1S54, 
however, several forms unrecognized by Audubon and Bachman had 
been described. These were noveboracensis (1829), nuttdlli (1832), 
maniculatus (1S45), californicus (1848), gossypinus (1853), sonori- 
ensis (1853), and texanus (1853). In 1857 Baird's Mammals of 
North America appeared c and added greatly to the knowledge of the 
group. With an acuteness w T hich is the more noteworthy when 
the scanty and imperfect nature of his material is considered, Baird 
sensed the distinctness of a number of forms not previously 
thought worthy, and also gave names to several new ones. More- 
over, he reviewed the related South American forms and presented 
the relationships of the species and minor groups then known much 
more satisfactorily than any previous writer. Thirteen forms were 
recognized by Baird under the following names: leucopus, texanus, 
gossypinus, gambelii, austerus, nuttalli, cognatus, boylii, myoides, 
sonoriensis, michiganensis, californicus, and eremicus. Twelve of 
these are still recognized, cognatus being the only one that did not 
represent at least a valid subspecific form. Under Hesperomys, 
Baird also placed Onychomys leucogaster and Oryzomys palustris 
with the rank of separate subgenera. After Baird, followed a period 
of comparative inactivity in which very few new forms were de- 
scribed, and the concept of the group remained nearly unchanged. 
Then came the mistaken ultraconservatism of Cones, who, in 1877,' z 
' lumped ' several of Baird's forms and also synonymized the major- 
ity of all names previously proposed for species of Peromysms. Thus 
under Hesperomys leucopus were placed no fewer than 13 names, 
none of which are now referred to the synonymy of that species. In 
addition to Hesperomys leucopus, however, Coues recognized the 

Proc. Biol. Soc. Wash., VII, p. 27, footnote, April. 1892. 

6 Ann. & Mag. Nat. Hist., Lond., ser. 6, XIV, p. 364, footnote. November, 1894. 

r Pac. R. R. Reports, VII, pp. 1-757, 1857. 

d Monogr. N. Am. Rodentia, pp. 43-105, 1S77. 


following: Hesperomys leu co pus gossypinus, H. 1. sonoriensis, H. I. 
eremieus, II. aureolus, II. michiganensis {= bairdi), II. califomicus, 
II. a-zteeus, and //. melanophrys. Like Baird, he included Ony- 
c/tomys and Oryzomys under Hesperomys as subgenera. The con- 
clusions of Cones were not seriously challenged for several years, but 
after 1885 collections began to increase, and from that time until the 
present many descriptions of new or supposed new forms have been 
published, and conceptions of the number and relationships of the 
species within the genus have rapidly changed. Various groups 
which had long been included as subgenera were eliminated and 
given independent rank, as Onychomys, Oryzomys, Tylomys, 
Rhipidomys, and various South American groups, until with the 
removal of Thomasomys in 1898 the genus Peromyscus became 
restricted to forms confined to North and Central America. How- 
ever, scarcely any of this recent work on the genus was of a revi- 
sionary nature, or if so it was confined to the limits of some small 
section. Certain papers of special importance, however, are worthy 
of mention. In 1890 Mearns published a brief but important 
synopsis of a number of the short-tailed western forms now included 
in the maniculatus group." Another valuable contribution was made 
in 1893, when Allen, 6 in reporting upon some large collections from 
Lower California, gave an extended discussion of the species of 
Peromyscus concerned. The species inhabiting Florida and all the 
forms of P. gossypinus have been quite thoroughly treated by Bangs. 
Two extensive papers were also published describing new forms 
from Mexico and Central America, one by Merriam d containing 20 
descriptions, the other by Osgood e containing 30. Short papers and 
mere descriptions have been numerous. In fact, no fewer than 
167 names for new or supposed new forms of Peromyscus have been 
proposed since 1885. Add to this the 14 contained in the present 
paper, and the total of 181 is reached/ 

The characters of the species and subspecies of Peromyscus are so 
subtle that even from the same material different persons may form 
different conclusions. For this reason, and also on account of the 
lack of even tentative revisionary work, the production of synonyms 
in this genus has been unusually large. Of the 167 names for sup- 

°Bull. Am. Mus. Nat. Hist. II, pp. 284-287, Feb. 21, 1890. 

6 Supra cit., V. pp. 185-197, Aug. 18, 1893. 

c Proc. Bost. Soc. Nat. Hist., XXVIII, pp. 193-203, March, 1.898, and Proc. Biol. 
Soc. Wash., X. pp. 119-125, Nov. 5, 1896. 

d Proc. Biol. Soc. Wash., XII, pp. 115-125, Apr. 30. 1898. 

e Proc. Biol. Soc. Wash., XVII, pp. 55-77, Mar. 21, 1904. 

I The authorship of these is divided as follows: Allen, 26; Alien and Chap- 
man, 4; Bailey, 3; Bangs, 16; Chapman, 3; Copeland and Church, 1; Elliot. 
15; Mearns, 13; Merriam, 28; Miller, 4; Osgood, 47; Rhoads, 11; Shufeldt, 1; 
Thomas, 8. 


posed new forms of Peromyscus proposed since 1885, 58, practically 
one-third, arc of more than doubtful status and are here treated as 
synonyms. The descriptions of these supposed new species are often 
misleading, since it has been usual to compare them with remote and 
entirely irrelevant forms, while their near relatives were ignored. 
Much time has been wasted in elaborate descriptions of shades of 
color common to nearly every species in the genus, while mention of 
relationships and differential characters has often been omitted. As 
a result, original descriptions have proved of little value to the re- 
viser, and for determining the applicability of names he has been 
compelled to depend largely upon type specimens. 


Variation in Peromyscus might well form the subject of extended 
discussion, but here it can be treated only in a general way, space 
forbidding the numerous tabulations which detailed study would 
require. Fortuitous individual variation is perhaps no greater than 
in most other genera of small rodents, but the range of seasonal, poly- 
chromatic, and local or geographic variation, is rather wide, so the 
genus may fairly be said to be more than usually variable. In- 
dividual variation is greatest in specimens from localities lying just 
between the ranges of two well-established forms. In fact, the com- 
plete range of difference between two extremes often may be found 
in series from such localities. In other cases, though obviously in- 
termediate, certain series show variations approaching either or both 
extremes. Also, variable intermediates may sometimes show T ten- 
dencies not apparent in either extreme but too unstable to be of 
subspecific importance. On the other hand, some intermediate series 
are quite uniform, but this is exceptional. Series typical of w^ell- 
established forms show comparatively little variation except in size, 
and this is not often great. In order to ascertain the normal varia- 
tion in size it is necessary to select carefully for illustration specimens 
that are unquestionably adult and that have been measured by one 
person, thus eliminating the personal equation. Below are given 
measurements of an entire series of P. s. prevostensis. These speci- 
mens were taken in two nights' t~ - jing at one place and carefully 
measured in the flesh by myself. Every one is fully adult. From 
the table it appears that the mean total length is almost exactly half- 
way between the extremes, and that the passage from one extreme to 
the other is very gradual, indicating that the mean is not misleading, 
as it often is when a preponderance of specimens is toward either of 
the extremes. In total length the greatest variation from the mean 
is the extreme of 230 mm., which is 14 mm., or about 6| per cent, in 
excess of the mean. Without detailing further evidence, it may be 
stated that this is about the normal percentage of variation in size 




throughout the genus. The same range of variation appears in both 
sexes — additional evidence that the average is reliable. Sexual varia- 
tion, as appears below, is so slight as to be practically wanting. This 
seems to hold throughout the genus, for though in a given series the 
maximum size is usually found among the females, the separate 
averages of adult males and females are always approximately the 

Measurement* of '/•> topotypes of Peromyscus s. prevostensis. 



Museum number. 



Hind foot. 

Museum number. 



Hind foot. 




' 108 














100837 . 















































Average of— 




•J 15. 3 


in:.. 7 
105. 'J 




JO. 'J 


Entire series (25 

males and 20 

Average of 25 


105. 2 


26. 2 

There is much variation in cranial characters that must be con- 
sidered individual. Most of the distinct species are fairly well char- 
acterized cranially, but the cranial characters of subspecies, when any 
are apparent, are exceedingly variable and seldom constant through- 
out a series. Often, however, they constitute average characters of 
considerable value. More or less tendency to dolichocephaly is some- 
times found in series representing species that are normally brachy- 
cephalic, and vice versa, and in si . 1 teases, of course, nearly all parts 
of the skull are affected. The teeth vary chiefly in size and seldom 
greatly. The pattern of the grinding surfaces of teeth at different- 
stages of wear, however, varies much, and in all comparisons of teeth 
is to be carefully considered. 

Variability of color, while often great, is usually not strictly in- 
dividual, but in most cases may be explained otherwise. It may 
be due to season, age, or color phase, and in some cases slight color 
differences, not considered specific or subspecific, seem obviously due 
to environmental causes and may be very local. Although there is 


only one complete annual molt, the constant change due to wear and 
its lack of uniformity in different individuals produce great varia- 
tion, so that comparatively large series seldom contain two individuals 
absolutely identical in color. Differences due solely to age are quite 
constant and of much the same character throughout the genus, but 
they too are complicated with the wear of pelage. (See Pelages, 
p. 19.) 

A sort of dichromatism is found in P. m. blandus, one phase being 
vinaceous gray and the other ochraceous buff. A few other forms, as 
sonoriensis and coolidgei, are slightly and less commonly dichromatic. 
Among western forms, variations of such an extremely local and 
sporadic nature often occur that one may almost believe them to have 
been produced in one or at most a very few generations. Such varia- 
tions, of course, are slight, and doubtless produced immediately upon 
contact with certain conditions. Thus if the range of a given form 
includes a few square miles of lava beds, specimens from that area 
show an appreciably darker color than the normal form occupying 
the surrounding region. And whenever similar conditions are re- 
peated elsewhere, even on a small scale, the same result seems to fol- 
low. Again, specimens from the bottom of a dark wooded canyon 
may be noticeably darker than those from an open hillside only a 
few hundred yards away. In the absence of absolute proof, one can 
scarcely avoid the suspicion that if the progeny of paler individuals 
were transferred at an early age to the habitat of darker ones, they 
would, quite regardless of t inherent tendencies, develop a darker 
color, or, similarly, a lighter color if the process were reversed. 

Local and geographic variations are great, so great, indeed, that, 
excepting a few species of very limited range, all the species have 
developed geographic peculiarities by means of which they have been 
subdivided into more or less numerous (geographic) races or sub- 
species. One species, P. maniculatus, which in its various forms 
ranges from sea to sea and from the Arctic Circle to the Isthmus of 
Tehuantepec, remains constant only where conditions are practically 
identical; hence it is represented by a definable subspecies in almost 
every fannal area which it enters. The readiness with which local 
variation is induced and established appears also from the large num- 
ber of distinguishable insular forms. Much of the local variation, 
however, can not be considered subspecific. Certain forms, although 
preserving the same general characters throughout a definite range, 
nevertheless show slight and sometimes unique variations in nearly 
every local series from within the range. In these cases, where no 
two series of specimens from respective localities are exactly alike, 
and where no two can be associated except upon the basis of char- 
acters common to all, it is necessary to disregard slight variations and 
treat the entire association under one name. 



Until recent years continuous and perfect intergradation was 
demonstrable only in relatively few cases. And even now, although 
proved beyond doubt in group after group, in many cases it is merely 
taken for granted. That intergradation exists even more widely 
than is generally supposed appears from the study of groups in 
which material is abundant. Of Peromyscus we have more com- 
plete series than of any other genus of American mammals — that is, 
not only are there more specimens, but many more localities are rep- 
resented and the gaps in known distribution are usually few. Bar- 
riers impassable to many other mammals have little effect on these 
mice, for they range continuously, although not always without un- 
dergoing change, from sea level to great altitudes, and f^om the 
very humid to the very arid regions. Moreover, since usually they 
are so abundant and easily obtained, representatives are available 
from nearly every locality in North America ever visited by a mam- 
mal collector. Within the range of one species (maniculatus) it is 
probable that a line, or several lines, could be drawn from Labrador 
to Alaska and thence to southern Mexico throughout which not a 
single square mile is not inhabited by some form of this species. 
They are wanting in the extreme north, but there is scarcely a corner 
south of the Arctic Circle in which they do not occur. With such wide 
and continuous distribution perfect intergradation must take place 
between related forms of different faunal areas, and with such 
complete collections this intergradation must be plainly evident in 
nearly all cases. 

Classification becomes, then, as has been said, & like dividing the 
spectrum and depends largely upon the standards set, for, theoretic- 
ally at least, the possibilities of subdivision are unlimited. It is not 
strange, therefore, that hundreds and even thousands of specimens 
are intergrades almost equally resembling two or more adjacent 
forms. Many of these intergrades for convenience may be referred 
with some degree of assurance to the form they most closely resem- 
ble, but many specimens fall so near the imaginary line between two 
or more subspecies that it is practically impossible to classify them 
other than as intergrades. A particularly troublesome class is one 
which approximates the color of one form and the cranial characters 
of another, thus reducing the question to one of relative importance 
of characters. 

"American col lecturs of wide experience, in comparing notes, regard as 
worthy <>f remark the few occasions on which they have found themselves in 
localities where they "couldn't catch Peromyscus," and in such places, as a 
rule, they were also unable to catch anything else. 

6 Ridgway, Birds North and Middle America, pt. I, p. x, 1901. 

66268— No. 28—09 2 


The description of new forms without a complete canvass of con- 
generic forms often has the unfortunate result of fixing names to 
intermediate and unrepresentative types. The same result is effected 
also by the describer who, though fully cognizant of relationships, 
does not hesitate to name a slight variation, the characters of which, 
as exhibited by specimens from a given locality, may prove later to 
be more fully developed in specimens from elsewhere. The reviser 
is often confronted with three names representing steps in develop- 
ment from one extreme to another, one of the designated forms thus 
being intermediate between the other two. If, as often occurs, the 
recognition of only two forms seems necessary, and the intermediate 
has been named before either of the extremes, its name, having 
priority, must stand, and it becomes necessary to decide which of 
the names representing the extremes shall be considered a synonym. 
It is well known that certain intermediate specimens so combine the 
characters of two subspecies that different authors may relegate them 
to different forms. It is readily seen that when such specimens are 
chosen as types the names of several forms may thus become as 
subject to change as are those on the labels of intermediate speci- 
mens. A reviser in dealing with such names is compelled first to 
determine the number of recognizable forms without regard to names. 
Then the various type specimens are referred according to their de- 
gree of resemblance to one or another of the recognizable forms — 
just as would be done in determining ordinary specimens. The names 
are then adopted or rejected according to priority and these deter- 

In several instances, particularly in the maniculatus group, two 
bona fide subspecies inhabit the same area and apparently maintain 
themselves distinct. Each may be traced by a different geographic 
route through every degree of intergradation to one parent ( ?) form. 
Thus, arcticus and algidus occur together in the upper Yukon Valley 
as if distinct species; arcticus ranges southward and eastward and 
intergrades with areas; algidus follows the coast route and through 
hylceus and macrorhinus also intergrades with oreas (see map, 
frontispiece). Therefore, if natural causes, sudden or gradual, were 
to eliminate the intergrades with oreas the formation of two dis- 
tinct species (arcticus and algidus), living side by side, would be 

Intergradation has been found quite frequently in unexpected 
quarters and many forms long supposed to be distinct species are 
now proved to be subspecies. This is significant of the result to be 
expected in other genera, specimens of which are less easily obtained, 
but which may have nearly or quite as continuous range as Peromys- 
cus. Everything seems to indicate, however, that few, if any, genera 
of American mammals show such widely separated differentiations 

1909.] PELAGES. 19 

and at the same time such unbroken series of intergrading forms as 
Peromyscus. Even the species most widely different are connected 
by forms more or less combining their characters, and the same is 
true in a large degree of the subgenera. 


Like many other mammals, the mice of the genus PeromyscMs appear 
to undergo only one complete annual change of pelage. The normal 
time for this molt, at least in temperate regions, is late summer or 
early fall, but from various causes the exact time is extremely varia- 
ble, so that season is usually of little value for determining the pelage 
of a given individual. The new pelage may be acquired in regular 
and obvious manner with the fresh coat well distinguished from the 
old worn one, the growth proceeding from before backward and the 
middle of the rump being the last part to be invested, or the change 
may be quite insidious and apparent only upon careful examination. 
The regular method is followed in the adults of most species, while 
the other is more often evident in immature individuals. 

The new pelage, when first acquired, is apparently unmixed with 
any of the preceding worn pelage, which soon entirely disappears, 
but new hairs continue to come in for some time, making the pelage 
fuller and thicker until it reaches its prime, usually in late fall and 
early winter. Besides the normal molt, in some cases, a distinct sec- 
ondary growth or perhaps a partial molt is shown by specimens 
which, though apparently in fresh pelage, are, as may be seen by 
lifting the hairs of the back and sides, largely covered with patches 
of short incoming hairs of uniform character. The complete new 
pelage remains much the same for some time (usually during winter), 
and then begins to show signs of wear. This is usually first evi- 
denced by a general brightening of color, the overlying black or 
dusky tips of certain hairs fading or being worn off, thus exposing 
more fully the various underlying shades of buff. The process of 
fading and abrading continues until the molt, producing various 
effects in different species. Commonly the dusky soon becomes al- 
most eliminated or altered to brown or pale cinnamon, so that it blends 
more perfectly with the main color. In species in which dusky pre- 
dominates on the back this becomes more contrasted with the sides, 
the dusky having been eliminated on one part sooner than on the 

In species having comparatively little dusky, the pelage, while still 
full, long, and apparently little worn, may become almost entirely 
a bright uniform shade of buff or tawny. This condition has some- 
times mistakenly been supposed to represent the very old individual 
in distinction from the supposed normal adult. It is true that the 


very bright rich colors are never assumed by the young and adoles- 
cents. Bui such colors appear to be only features of a stage through 
which any adult may pass annually, though since largely the result 
of external influences (abrasion and fading), they necessarily vary 
greatly in different individuals. Thus it often happens that the 
pelages of two individuals living side by side are at the end of a 
season in quite different stages of wear. 

Besides the differences due to wear and renewal of the coat, there 
are three fairly distinct phases due to age — the juvenile (young in 
first coat), the adolescent, and the adult. The young in first coat is 
usually a uniform slaty gray or some similar shade." The hair is 
slightly paler terminally than basally and is more or less woolly in 
appearance — at least not smooth and compact. This stage is suc- 
ceeded by the adolescent pelage, which first appears on the middle of 
the sides. Its growth proceeds rapidly upward on each side until union 
is effected in the middle of the back, and then incloses the rest of the 
bocty, the rump and nape usually being the last parts to be covered. 
In its early stages this adolescent pelage is plainly distinguishable 
from the adult pelage. The hair is shorter than in the adult, the 
main color is duller and paler, and the dusky is more uniformly 
distributed. It varies but little through many species, and the gen- 
eral effect is usually close to broccoli brown. It is difficult to deter- 
mine how long this pelage is worn, but it is doubtless renewed at 
latest within a year. The succeeding coat may be somewhat paler 
and grayer than the fully adult, but as a rule is so similar to it that 
further distinction is scarcely possible. Except in northern forms, 
breeding is continued during the greater part or all of the year (see 
Remarks under P. californiciis, p. 236), so that specimens of various 
ages may be taken at almost all seasons. 

Consideration of pelages is of the highest importance in making 
comparisons of closely related forms. Except in large collections, 
it is very difficult to find specimens of different forms absolutely 
comparable as to condition of pelage. Indeed, it is sometimes hard 
to find two absolutely comparable specimens of one form even in a 
large series collected at one time and place. The fact that a specimen 
was collected at a certain season does not always warrant assumption 
that its pelage is the one that is (or ought to be) representative of 
that season. This is particularly true of southern forms, many of 
which seem to change pelage regardless of season. The process of 
change is constant ; that is, a new pelage begins to be altered slightly 
as soon as it is acquired, and before renewal it may pass through vari- 
ous stages of fading and abrading, each more or less different from 
the others. Add to this the different shades of color distinguishing 

°An exception is found in the subgenus Ochrotomys, in which the young are 
colored like the adults. 


juveniles, adolescents, adults, and senescents, and the result is an 
amount of variation that can be demonstrated only by large scries 
taken at different seasons. Insufficient material, and consequent 
failure to appreciate these variations, have of course been the chief 
causes leading to the bestowal of different names upon identical 

The pelages here described are placed chiefly under two heads — 
the ' unworn pelage,' which indicates the fresh coat in its prime, and 
the ' worn pelage,' which usually is that of the rather decided degree 
of wear shown just before the molt. The various intermediate stages 
between the two can be indicated only in a general way. The 
' adolescent pelage ' and that of the ' young in first coat ' are so 
similar in most forms that descriptions of them have not been given 
in all cases. 


The description of the intergrading forms of a genus like Pero- 
myscus presents unusual difficulties. Differences apparent enough 
to any tyro are beyond the powers of description of the practiced 
professional. Available words constantly signify either too much 
or too little and in many cases may mislead. Besides differences 
that can be perceived but not described, others doubtless exist in the 
living animals that in prepared specimens are rarely even perceptible. 

As Bangs says : & 

Most of the closely related forms of white-footed mice look very different 
from each other when one is trapping and handling them in the flesh. This 
' aspect difference ' as Professor Shaler aptly calls it, is subtle and hard to 
define, and may disappear almost entirely when the animals are made into the 
conventional museum skins or preserved in spirits, thus leaving the characters 
on which species and subspecies are based very slight in comparison with what 
they were in life. 

Since the general color and color pattern are so much the same 
throughout the genus, comparative descriptions are employed in 
almost all cases. In addition, although it causes some repetition, 
complete color descriptions are given for nearly all the forms. In 
every case, typical specimens have been compared carefully with the 
plates of Ridgway's Nomenclature of Colors for Naturalists, c which. 

"However, after examining several comparatively small collections, one can 
only wonder that so many really correct diagnoses have been made. Forms 
which appear quite distinct in view of large series of perfect specimens are 
most difficult to distinguish with only poor material. On the other hand. 
differences of pelage are often magnified in small collections where two very 
different pelages may be represented only by series from two widely separated 
localities, and thus the belief that they represent different forrns is easily 

6 Proc. Biol. Soc. Wash., X, pp. 120-121, Nov., 1896. 

c Boston, Mass., 1886. Now out of print. 


though of smaller scope than is desirable and unfortunately not 
widely accessible, is yet the only available standard. Since general 
color terms are so indefinite, they have been supplemented by the 
terms used by Ridgway, or, if possible, they are used in the sense 
of the unqualified term as given by Ridgway. Thus the term rufous 
is employed in none of the variable popular senses, but to describe 
the shade so-called by Ridgway (No. 7, PI. IV). Nearly every 
species of Peromyscus has two colors independently combined, and 
the relative amount of each can not be stated in exact terms. An 
attempt to obviate this difficulty has been made by defining the two 
colors and also the ' general effect,' that is, the color produced by the 
blending of the two as seen when the specimen is held in a good 
light at a short distance from the eyes. 


All measurements are in millimeters. Unless otherwise stated, the 
external measurements are those taken in the flesh by the collector, 
as follows: Total length (tip of nose to tip of tail) ; tail vertebrae 
(never measured to end of hairs) ; and hind foot (to end of longest 
claw). The measurement of the ear has been taken in most cases 
from the dry skins of specimens in which the ear has not been dis- 
torted in drying. The means and extremes of ten normal adult speci- 
mens are given so far as possible. Since there is so little sexual dif- 
ference in size (see p. 15), the averages, except in special cases, are 
based upon series containing specimens of both sexes. Cranial 
measurements have been taken with great care with finely adjusted 
calipers reading tenths of millimeters by vernier. Although not 
equally valuable for all forms, the following cranial measurements 
have been uniformly taken : 

Greatest length, the length over all from the tip of the nasals to 
the posterior bulge of the braincase. 

Basilar length, the basilar length of Hensel from the inferior lip 
of the foramen magnum to the incisor. 

Zygomatic width, the greatest distance between the outer sides of 
the zygomata. 

I nterorbital constriction, the width of the most constricted part of 
the interorbital space. 

Interparietal, the greatest length and width. 

Nasals, the greatest length along the suture between the nasals. 

Shelf of bony palate, the distance from the posterior ends of the 
anterior palatine foramina to the anterior border of the interptery- 
goid fossa. 

Palatine slits, the greatest length of the anterior palatine foramina. 

Diastema,) anterior base of upper molars to posterior base of incisor. 


Postpalatal length, the distance from the anterior border of the 
interpterygoid fossa to the inferior lip of the foramen magnum. 

Maxillary toothrow, the alveolar length of the three upper molari- 
form teeth. 


Although at the outset it appeared that a thoroughly satisfactory 
key to the species of Peromyscus was out of the question, still a key 
of some sort seemed imperative. Effort has been made, therefore, to 
devise one by means of which normal adults may be identified. In 
its construction all semblance of natural order is disregarded and in 
many cases solely geographic divisons are made. This course is ob- 
jectionable, if for no other reason than that further collecting and 
study may extend the limits of the ranges of many species. How- 
ever, the ranges of the species of Peromyscus are better known than 
those of most other mammals, and it is therefore probable that a key 
based on geographic ranges will be found no more subject to change 
than one based on natural characters. Owing to the wide variation 
among the subspecies of many of the species, it has been necessary to 
introduce the same species in various parts of the key. Keys have 
been attempted also for the intergrading subspecies of each species, 
although obviously they must prove more or less unsatisfactory. 
They are largely geographic and are intended only as slight aids 
rather than invariable guides to identification. 

In revising groups of animals and plants, it is desirable that the 
results be made useful to as large a class as possible, in addition to 
professional students. The present group, however, is a subtle one, 
and the best that can be done will not fully meet the needs of pro- 
fessionals, much less of amateurs. The identification of the species 
of Peromyscus is sufficiently difficult, and that of the subspecies is a 
subject for experts, or at least for those having access to large col- 
lections. In most cases, the best the amateur can hope to do is to 
identify his specimens as to species; for his subspecific determinations 
he must depend largely upon the accompanying maps. 


More than 27,000 specimens are recorded in the following pages, be- 
ing practically all those contained in the principal American col- 

An attempt has been made to refer every specimen examined 
to a described species or subspecies, but it must be admitted that 
in the case of many intermediate specimens it makes little differ- 
ence whether they are called by one or another name. The fact that. 
two forms intergrade may be shown conclusively by specimens, but 


on which side of the imaginary dividing line the intergrading speci- 
mens belong linisl often remain largely a matter of individual 
opinion. Many specimens, therefore, have been referred arbitrarily 
to <»ne or another of closely related forms. Such arbitrary reference 
is often necessary, not only in cases of intergrades, but of immature 
specimens or small series in noncommittal condition of pelage, and 
may be influenced by geography or by various considerations apart 
from the specimens themselves. Intermediate specimens are fre- 
quently noted as such in the record-, but since there is every degree 
of intergradation, it is impossible to carry this plan out consistently, 
and therefore it can not safely be assumed that specimens are typical 
because they are not noted as intermediate. 


Although several superspecific groups may be characterized as 
subgenera within the genus Peromysats, it does not appear necessary 
to remove any of them as independent genera. Thus the natural and 
well-known general concept of the genus is retained, while associa- 
tions of species not formerly segregated are fully recognized by the 
employment of subgeneric names. Certain authors already have 
chosen to elevate the subgenera Megadontomys and Baiomys to 
generic rank a and other similar mammalian groups are frequently 
treated as genera. Some make no attempt to justify their recognition 
of such groups other than the claim that the characters, however 
slight, are unmistakable, while others urge it merely as a matter of 
convenience, because the groups are of " unwieldly proportions," b or 
" as consistent with the finer ultimate divisions/' c So far as Pero- 
mysens is concerned, the finer ultimate divisions are mostly inter- 
grading subspecies and the unwieldy proportions are caused by the 
masquerading of many of these subspecies as full species. The num- 
ber of bona fide species scarcely exceeds forty, and of these some half 
dozen eventually may be reduced in rank. 

The unwieldiness of a genus is properly to be judged by the number 
of species it contains, without regard to the subspecies. The constant 
tendency in taxonomic work seems toward analytic methods at the 
expense of synthetic. This is shown especially in the multiplication 
of genera which have the function merely of emphasizing some slight 
distinction, while the groups which formerly served to indicate re- 
semblances of associated species are unrecognized. 

Unanimity in regard to the limits of genera and subgenera is 
scarcely to be hoped for. but some effort may be made to preserve 

°Cf. Bangs, Bull. Mus. Comp. Zool., XXXIX, p. 27, 1902: Mearns, Mamms. 
Mexican Boundary, Bull. No. 56, l". S. Nat. Mus., p. 381, 1907. 
6 Cf. Bangs. Bull. Mas. Comp. Zool.. XXXIX, p. 27, 1902. 
c Allen. Princeton Exped. Patagonia, III, Zool. I, p. 165, 1905. 

1909.] SUBGENERA. 25 

both the genus and subgenus as classificatory categories. Those who 
assume that subgenera as such are useless must necessarily recognize 
more and more groups as genera until the distinct ion between the 
genus and the species becomes so slight, as to be of little taxonomic 
value, while, at the same time the gap between the genus and the 
group of next higher rank is correspondingly increased. It is diffi- 
cult to understand the reason for this attitude, for, while it is held 
by those who draw very fine distinctions and are only too willing to 
see generic significance in slight characters, it actually operates to 
reduce the number of categories of classification between the sub- 
family and the species, and thus results, not in an improved and more 
discriminating system of classification, but one with fewer groups and 
fewer possibilities for the indication of relationships. 

The use of subgenera provides a means of adjusting the differences 
usually existing between the general zoologist and the specialist. The 
generic name answers all the purposes of the general zoologist while 
the specialist may use as many subgenera as he desires and meet all 
the requirements of discriminating classification. This also operates 
to conciliate the amateur, whose outcries against the continual chan- 
ging of names by specialists will thereby be lessened. Although these 
protests are often unreasonable, the specialist should remember that 
his scheme of nomenclature to be truly successful must answer the 
purposes of others as well as himself. If the specialist conserva- 
tively retains well-known and natural generic groups he may segre- 
gate subgenera indefinitely without retarding the progress of exact 
taxonomy, and, at the same time, without interfering with the less 
exacting needs of the general zoologist and the amateur. Moreover, 
further advantage is found in the fact that the percentage of legiti- 
mate changes of names that would confront the much-abused ama- 
teur would be greatly reduced; for changes of subgeneric names on 
account of preoccupation and other causes would in most cases con- 
cern only the specialist. One author a advocates the abolition of sub- 
genera in order to remove the temptation to give them the rank 
of genera — little more than a confession of weakness. It appears to 
be true, however, that with some systematists the establishment of 
a subgenus fosters attempts to elevate it to generic rank. 

Most of the subgenera of Peromyscus are well characterized, usually 
by a combination of characters; but if a single character becomes 
pronounced it is merely an extreme development which may be traced 
back by stages to a widely different condition. Thus the subgenera 
Haplomylomys and Megadontomys, although fairly circumscribed 
and definable, seem to be at opposite ends of an almost continuous 
series in which the subgenus Peromyscus combines most of their 
characters. The subgenus Podomys (including P. floridanus only) 

"Hartert, Auk, XXIII, pp. 120-122, Jan. 1906. 


seems to have an absolute character in the number of its plantar 
tubercles, but within the subgenus Peromyscus there is much varia- 
tion in this respect, and specimens of the maniculatus group occa- 
sionally have the sixth tubercle very small and nearly obsolete. The 
subgenus Baiomys is usually recognizable by small size {P. m. 
pallescens, of the subgenus Peromyscus, is scarcely larger) , but most 
of its characters are to be found elsewhere in the genus. Ochro- 
tomys is a subgenus based upon a single aberrant form (P. nuttalli), 
which seems to have no very close relatives, although its general 
characters are obviously those of Peromyscus. 


The various species of this genus have widely different local habi- 
tats. Some inhabit woodland, others swamps and watercourses, some 
open upland prairies, and others rocks, cliffs, and arid desert regions. 
Even single species live under a surprising diversity of conditions. 
All are habitually nocturnal, though occasionally individuals under 
unusual circumstances may be seen abroad by day. They wander 
widely at night, and unlike the meadow mice (Jlicrotus) do not form 
beaten runways. They do not hesitate, however, to freely utilize 
such runways made by other rodents. Collectors soon learn to recog- 
nize the places most frequented by them, but in a region where they 
abound they may be caught in traps set in almost every conceivable 
situation. Although sometimes welcomed by the inexperienced col- 
lector, to whom they insure a catch of some sort, they are a source of 
annoyance to the more ambitious trapper, who finds them continually 
springing traps set for more desirable species. 

Many of them doubtless burrow to some extent, but in most cases 
those that live underground occupy natural openings or retreats 
formed by other animals. Crevices in rocks and cliffs are the favorite 
haunts of many species. The prairie forms, as P. m. bairdi and 
others, are said to make short, simple burrows in the ground in which 
their nests of soft grass are placed. The woodland forms, as P. leu- 
copus, though living largely on the ground, are to some extent arbo- 
real, and P. nuttalli is largely so. They build their nests among 
roots and in old stumps and hollow trees, often occupying the deserted 
nesting cavities of birds, as woodpeckers, bluebirds, and chickadees. 
Sometimes also a bird's nest in a small bush is appropriated and 
temporarily used, or perhaps remodeled and permanently occupied. 
That they also climb about to some extent in trees not occupied as 
nesting sites is often evidenced by the presence of their dried drop- 
pings in crevices and crotches at some distance from the ground. 
They do not hibernate, but remain active throughout the winter, even 
in northern latitudes. 


Although the food habits of various species arc not quite the same, 
in general it may safely be said that very few feed extensively upon 
green and succulent food such as is taken by the meadow mice, but 
nearly all prefer dry food, especially seeds and small nuts. In cap- 
tivity they are omnivorous, and, like the house mouse, find everything 
in man's larder palatable. Sometimes, when confined, they turn can- 
nibals, and even in their natural habitat will often devour the dead 
bodies of their own kind or of other mice that have been caught in 
traps. The common form of the northeastern United States (P. I. 
noveboracensis) is especially fond of basswood seeds, pits of wild 
cherries, beechnuts, and acorns, and often stores them in burrows or 
in cavities in old stumps. It eats also seeds of many wild shrubs, 
weeds, and grasses. In wooded regions or on waste land, where it 
commonly lives, it is not very injurious to agriculture, but when 
living about the edges of cultivated ground it sometimes devours or 
carries away grain in considerable quantities. Kennicott records 
that in western New York there was found " within a stump in a 
clover field, several quarts of clean seed of red clover collected by a 
family of these mice." It occasionally gnaws the bark of young 
fruit trees or nursery stock, but such harm is more often due to 
meadow mice {Microtus). 

Doubtless more damage is done by western forms than eastern, 
as many of the former are less confined to woodland. Thus 
P. in. bairdi and other forms of the maniculatus group, being 
naturally inhabitants of open ground, readily betake themselves 
to cultivated fields under the conditions of advancing civilization. 
In such cases, although grain and other products form only a 
small part of their food, they do considerable injury on account of 
their great numbers. Throughout practically all of the western 
United States they exist in countless numbers, perhaps exceeding 
those of the other combined mammalian inhabitants of the region. 
They are extremely prolific, bearing from 4 to 6 young in a litter and 
breeding throughout the entire year, at least in temperate regions. 
Evidently whatever their food habits, these mice must play an impor- 
tant part in maintaining the balance of nature, and no doubt they 
partially offset some of their damage by consuming the seeds of 
noxious weeds. 

Nearly all the species readily enter buildings in search of food and. 
finding an easy living, make themselves permanently at home. They 
do not often live in large cities nor where the house mouse (Mus 
musculus) is established, as that species, though smaller than most 
species of Peromyscus, seems able to drive them away. The domest i<- 
depredations are therefore confined to rural districts and small towns 

Agricultural Report for 1856, r. S. Patent Office, p. 91, 1857. 


not yet infested by house mice. In such places, particularly in the 
north, they are quite as pestiferous as house mice, cutting up fabrics 
for nest materials, destroying ail kinds of foodstuffs, and doing much 
damage about granaries, straw or hay stacks, and outbuildings. In 
the interior of Canada they infest trappers' 1 lonely cabins and levy 
tribute on the provisions, and at trading posts they enter warehouses 
and damage the merchandise. Under such circumstances they are 
similar in habits to house mice, and can be destroyed by the same 
methods — trapping or poisoning — but they can be kept out of prem- 
ises only by constant vigilance, for those killed are soon replaced 
from the limitless supply of the neighboring woods and fields. 

On the whole they are less injurious to agricultural interests than 
meadow mice, but nevertheless they are vermin and their undue 
increase should be checked. This can be accomplished best by trap- 
ping and poisoning, as in the case of meadow mice." On account of 
their more decidedly nocturnal habits, they are preyed upon by 
hawks less than meadow mice, but they are eaten in large numbers 
by nearly all species of owls. The smaller carnivorous mammals also, 
(specially weasels, are among their enemies, and the larger snakes 
destroy them to some extent. The continued decrease of these pre- 
daceous animals through a mistaken persecution by man must result 
in a great increase of these and other mice. Owls at least should be 
protected by law, and a knowledge of the important part played by 
harmless snakes in destroying these and other noxious rodents should 
be disseminated as widely as possible, especially among children. 

List of species and subspecies of Peromyscus, with type localities. 

Subgenus Peromyscus. 
Name. Type locality. 

Maniculatus group: 

P. maniculatus Labrador. 

P. m. gracilis Michigan. 

P. in. aMetorum ^ James River, Nova Scotia. 

P. m. argentatus Grand Manan Island, New Brunswick. 

P. in. crctiuix Magdalen Islands, Quebec. 

P. tii. nuMterrw Roan Mountain, North Carolina. 

P. m. arcticus Fort Simpson, Mackenzie. 

P. in. orcas Mount Baker Range, British Columbia. 

P. in. hylaeus Prince of Wales Island, Alaska. 

P. m. algidus Lake Bennett, British Columbia. 

P. vi. Jceeni Queen Charlotte Islands, British Columbia. 

P. in. macrorhinus Mouth Skeena River, British Columbia. 

P. m. artemisice Ashcroft, British Columbia. 

P. in. satitratus Saturna Island, British Columbia. 

P. m. hollisteri San Juan Island, Washington. 

"See Bailey, N. Am. Fauna No. 17, p. S, 1898; Lantz, Yearbook U. S. Dept. 
Agric. for 1905, pp. 363-376, 1906. 


Name. Type locality. 

Manic ul at us group — Continued. 

P. to. austerus Fort Steilacoom, Washington. 

P. m. rubidus Mendocino, California. 

P. to. gambeli Monterey, California. 

P. m. rufinus San Francisco Mountain, Arizona. 

P. m. nebrascensis Calf Creek, Montana. 

P. m. luteus Kennedy, Nebraska. 

P. to. bairdi Bloomington, Illinois. 

P. to. pallescens San Antonio, Texas. 

P. m. blandus Escalon, Chihuahua. 

P.m.fulvus Oaxaca, Oaxaca. 

P. in. labccula Ocotlan, Jalisco. 

P.m. sonoricnsis Santa Cruz, Sonora. 

P. to. coolidgei Santa Anita, Lower California. 

P.m. margin ita Margarita Island, Lower California. 

P.m. dementis San Cleniente Island, California. 

P.m.eataUnw Catalina Island, California. 

P.m. dubius Todos Santos Island, Lower California. 

P. to. geronimensis San Geronimo Island, Lower California. 

P.m.cineritius San Roque Island, Lower California. 

P.m. magdalenw Magdalena Island, Lower California. 

P. sitkensis Sitka, Alaska. 

P. s. prevostensis Queen Charlotte Islands, British Columbia. 

P. polionotus Georgia. 

P. p. albifrons Whitfield, Florida. 

P.p.niveircntris Opposite Micco, Florida. 

P. p. phasma Anastasia Island, Florida. 

P. p. rhoadsi Anclote River, Florida. 

P.melanotis Las Vigas, Veracruz. 

Leucopus group : 

P.leucopus Near mouth of Ohio River. 

P.l.noveboraeensis New York. 

P.l.ammodytes Monomoy Island, Massachusetts. 

P.l.fusus Marthas Vineyard, Massachusetts. 

P. 1. aridulus Fort Custer, Montana. 

P. 1. ochraceus Winslow. Arizona. 

P. 1. tornillo El Paso, Texas. 

P. 1. arizoncB Fairbank, Arizona. 

P. 1. texanus West central Texas. 

P. 1. mesomelas Orizaba, Veracruz. 

P. I. castaneus Yohaltun, Campeche. 

P. 1. afflnis Barrio, Oaxaca. 

P. I. cozumelw Cozumel Island, Yucatan. 

P. gossypinus Riceboro, Georgia. 

P. g. megacephalus Woodville, Alabama. 

P. g. palmarius Opposite Micco, Florida. 

P. g. anastasw Anastasia Island, Florida. 

Boylei group : 

P. boylei Middle Fork American River, California. 

P. b. rowleyi— Noland Ranch, Utah. 

' P. b. attivateri Kerr County, Texas. 

P. b. spicilegus San Sebastian, Jalisco. 


Name. Type locality. 

Boylei group — Continued. 

P. b. simulus San Bias, Tepic. 

/'. b. madrensis Tres Marias Islands. Mexico. 

P. b. evides Juquila, Oaxaca. 

P. b. levipes Mount Malinche, Tlaxcala. 

P. b. aztccus Mirador. Veracruz. 

/'. oaxacensis Cerr<> San Felipe, Oaxaca. 

P. hylocetes Patzcuaro, Michoacan. 

P. pectoralis Jalpan, Queretaro. 

P. p. eremicoides Mapimi, Durango. 

P. /*. laceianus Kerrville, Texas. 

Truei group : 

P. truei Fort Wingate, New Mexico. 

P. /. gilberti Bear Valley, California. 

P. t. martirensis San Pedro Martir Mountains, Lower California. 

P. t. lagunw Laguna Mountains, Lower California. 

P. /. gratvs Tlalpam, Mexico. 

P. t. gentilis Lagos, Jalisco. 

P. nasutus Bstes Park, Colorado. 

P. polius Colonia Garcia, Chihuahua. 

P. difficiUs Valparaiso Mountains, Zacatecas. 

P. d. amplus Coixtlahuaca, Oaxaca. 

P. (1. felipensis Cerro San Felipe, Oaxaca. 

P. bullatus Perote, Veracruz. 

Melanophrys group : 

P. melanophrys Santa Efigenia, Oaxaca. 

P. )». samorce Zamora, Michoacan. 

/'. m. consobrinus Berriozabal, Zacatecas. 

P. xenurus Durango, Durango. 

P. mekisturus Chalchicomula, Puebla. 

Lepturus group : 

P. Upturns Mount Zempoaltepec, Oaxaca. 

/'. lophurus Todos Santos, Guatemala. 

P. Simula t us Jico, Veracruz. 

/'. nudipes La Carpintera, Costa Rica. 

/'. furvus Jalapa, Veracruz. 

P. guatemalensis Todos Santos, Guatemala. 

P. dltilaneus Todos Santos, Guatemala. 

Mexican its group : 

P. mexicanus Mirador, Veracruz. 

P. ;/*. totontepecus Totontepec, Oaxaca. 

P. m. teapensis Teapa, Tabasco. 

P. ?». saxatilis Jacaltenango, Guatemala. 

P. m. gymnotis Guatemala. 

P. allophylus Huebuetan, Chiapas. 

P. banderanus Valle de Banderas, Tepic. 

P. b. vicinior La Salada, Michoacan. 

P. h. angelemis Puerto Angel. Oaxaca. 

P. yucatanicus Chichenitza, Yucatan. 

P. y. baditis Apazote, Carupeche. 


Name. Type locality. 

Megalops group : 

/'. megalops Near Ozolotepec, Oaxaca. 

P. m. auritus Near Oaxaca, Oaxaca. 

P. in. melanurus Pluma, Oaxaca. 

P. melanocarpus Mount Zempoaltepec, Oaxaca. 

P. zarhynchus Todos Santos, Guatemala. 

Subgenus Megadontomys. 

/'. thomasi Near Chilpancingo, Guerrero. 

P. nelsoni Jico, Veracruz. 

P. flavidus Boquete, Chiriqui. 

Subgenus Ochbotomys. 

/'. nuttalli Norfolk, Virginia. 

P. it. aureolus Soutb Carolina. 

Subgenus Podomys. 

P. floridanus Gainesville, Florida. 

Subgenus Haplomylomys. 

P. crinitus Sboshone Falls, Idaho. 

P. c. auripectus Bluff City, Utah. 

P. c. Stephens* San Diego County, California. 

P. californicus Monterey, California. 

P. c. insignis Dulzura, California. 

P. crcmicus Fort Yuma, California. 

P. e. anthonyi Grant County, New Mexico. 

P. r. phaeurus Hda. La Parada, San Luis Potosi. 

P. c. tiburonensis Tiburon Island, Sonora. 

P. e. fraterculus Dulzura, California. 

P. e. cedrosensis Cedros Island, Lower California. 

P. e. eva San Jose del Cabo, Lower California. 

P. e. arius Ceralbo Island, Lower California. 

P. e. insulicola Espiritu Santo Island, Lower California. 

P. e. polypolius Margarita Island, Lower California. 

P. goldmani Alamos, Sonora. 

Subgenus Baiomys. 

P. taylori San Diego, Texas. 

P. t. subatcr Near Columbia, Texas. 

P. t. paulus Rio Sestin, Durango. 

P. t. analogies Zamora, Michoacan. 

P. museulus ' Colima, Colima. 

P. m. brunncus Jalapa, Veracruz. 

P. m. nigrcscens Valley of Comitan, Chiapas. 


New subspecies. 
Name. Type locality. 

P. maniculatus eremus Magdalen Islands, Quebec. 

P. maniculatus algidus Lake Bennett, British Columbia. 

P. maniculatus hollisteri— San Juan island. Washington. 

/'. maniculatus margaritce— Margarita Island, Lower California. 

P. maniculatus magdalenw-. Magdalena Island, Lower California. 

/'. polionotUS ul hi f ions Whitfield, Florida. 

/'. Inn-opus aridulus Fort Custer, Montana. 

P. Ian-opus oohraceus Winslow, Arizona. 

/'. truei lagunw La Laguna, Lower California. 

/'. megalops melanurus Pluma, Oaxaca. 

P. eremicus insulicola Espiritu Santo Island, Lower California. 

P. eremicus avius Ceralbo Island, Lower California. 

P. eremicus polypolius Margarita Island, Lower California. 

P. taylori analogus Zamora, Michoacan. 

Key to subgenera. 
a. Plantar tubercles 6. 

b. Coronoid process of mandible small and but slightly elevated, or, if not, then 
hind foot more than 16. 
c. Two principal outer angles of m 1 and m 2 with more or less well-developed 
accessory tubercles or enamel loops (see PI. VIII, figs. 2, 2a) ; mammse | 
(i. |, a. g, p.}). 

d. Ears dusky or dusky edged with whitish, in slight contrast to color of 

body : posterior palatine foramina about midway between interptery- 

goid fossa and anterior palatine foramina ; dentine spaces of molars 

mostly confluent. 

e. Size small to large; hind foot less than 32 (except in guatemalen- 

sis and zarhynchus) ; outer accessory tubercles or loops of m 1 

and m 2 only slightly developed Pcromijscus (p. 32) 

< T. Size very large ; hind foot always more than 30 ; outer accessory 
tubercles or loops of m 1 and m 2 well developed. 

Megadontotnys (p. 218) 

dd. Ears bright ochraceous, same color as body : posterior palatine foramina 

nearer to interpterygoid fossa than to anterior palatine foramina ; 

dentine spaces of molars mostly closed Ochrotomys (p. 222) 

cc. Two principal outer angles of m 1 and m 2 simple, without accessory cusp:; 
or enamel loops or with rudimentary ones (see PI. VIII, figs. 3—4) ; mamm r § 

(i. 3, a. ;;, p. g) Haplomylomya (p. 228) 

bh. Coronoid process of mandible well developed ; size very small, hind foot not 

more than 17 -Baiomys (p. 252) 

no. Plantar tubercles 5 Podomya (p. 226) 

Genus PEROMYSCUS Gloger. 

Hesperomys Waterhouse, Zool. Voy. H. M. S. Beagle, Pt. II, Mamm., pp. 74-77, 
1839— in part only. 

Perom-yscus Gloger, Hand und Hilfsbuch Naturgesch., I, pp. xxx, 95, 1S41 ; 
Thomas. Ann. and Mag. Nat. Hist., ser. 6, XIV. p. 364. Nov., 1894: XV, 
pp. 190, 192, i'cW.. 1895. Type, Peromyscus arboreus < =P. 1. noveboracensis). 

Sitomys Fitzinger, Sitzungsber. Math. -Nat. CI. K. Akad. Wiss., Wien, LVI, p. 
97, 1867; Merriam, Proc. Biol. Soe. Wash.. VII, p. 27, 1892. Type, C'ricetiis 
myoides (=/'. /. noveboracensis). 

Vesperimus Coues, Proc. Acad. Nat. Sci. I'hila., p. 178, 1874; Allen, Bull. Am. 
Mus. Nat. Hist.. Ill, p. 224. May 7. 1891. Type, Hesperomys leucopus 
(=Peromyscas Inn-opus >. 

Baiomys True. Proc. I". 8. Nat. Mus.. XVI, p. 758, Feb. 7. 1894. Type, Hes- 
peromys {Vesperimus) taylori {—Peromyscus taylori). 


Triwodontomys Rhoads, Proc. Acad. Nat. Sci. Phila., pp. 256-257, Oct., 1894. 
Type. Sitomys insolatus (=P. 1. sonoriensis) . 

Megadontomys Merriam, Proc. Biol. Soc. Wash., XII, pp. 115-116, 125, fig. 20, 
Apr. 30, 1898. Type. Peromyscus thomasi. 

Haplomylomys Osgood, Proc. Biol. Soc. Wash., XVII, pp. 53-54, Mar. 21, 1904. 
Type, Hesperomys cranial* (=Peromyscus eremicus). 

Podomys Osgood, posted, p. 226. Type, Hesperomys floridanus (=Peromyscus 

Ochrotomys Osgood, posted, p. 222. Type, Arvicola nuttalli (—Peromyscus nut- 
tall /). 

Type. — "(Peromyscus arboreus [Cricetus myodesW Gapper])" 
Gloger, 1841 =Peromyscu8 leucopus noveboracensis (Fischer). 

Generic characters. — Form murine; tail long, at least more than 
one-third of total length, often decidedly more than half; tail with 
scaly annulations more or less concealed by hair ; ears relatively large, 
membranous, and thinly clothed with hair; soles of hind feet 
5-6-tuberculate, hairy proximally or naked medially to calcaneum; 
internal cheek pouches more or less developed; mamma? | or f . 

Skull with braincase rather thin-walled, smooth, and but little 
ridged ; supraorbital border smoothly rounded, sharp-angled, or 
beaded ; interparietal well developed ; zygomata slender, depressed to 
level of palate ; infraorbital foramen compressed-triangular, bounded 
on the outside by a broad thin plate ; anterior palatine foramina long, 
slitlike, and separated by a thin bony septum; posterior border of 
palate squared or rounded, without lateral pits, and situated about 
even with plane of posterior roots of last molars; audital bullae more 
or less inflated and obliquely situated. Ramus of mandible relatively 
long, slender, and straightened; coronoid process (except in Baiomys) 
short and slightly developed ; mandible but slightly expanded by base 
of root of lower incisor. Molars rather weak, brachyodont and tuber- 
culate, the tubercles in two longitudinal series or in four incomplete 
longitudinal series consisting of two principal median series and two 
much subordinated lateral series; upper molars 3-rooted, lower 2- 
rooted; molar series decreasing in size from before backward, the 
third upper molar subcircular and usually less than half as large as 
the second ; first upper molar with 5 principal tubercles, an anterior 
median one and two pairs of lateral ones (the anterior one partially 
divided in Megadontomys) , with or without subsidiary tubercles in 
the salient angles ; upper incisors without grooves. 

Subgenus PEROMYSCUS Gloger. 

Subgeneric characters. — Pattern of color usually bicolor, the under- 
pays usually white and sharply distinguished from the upperparts; 
young in first coat differently colored from adults; 6 ears more or less 

a Distinguishing from Baiomys and Ochrotomys. 
h Distinguishing from Ochrotomys. 
66268— No. 2S— 09 3 


dusky, somewhat contrasted with rest of upperparts; plantar tuber- 
cles 6 ; h mammae f (i. |, a. #,| p. \). c Posterior palatine foramina about 
midway between interpterygoid fossa and anterior palatine foramina ; f 
coronoid process of mandible usually small and only slightly ele- 
vated ; accessory tubercles present in salient angles of first and second 
upper molars; d outer accessory tubercles of ml and m2 only slightly 
developed ; e dentine spaces of worn molars mostly confluent/ 

Key to species of the subgenus Peromyscus.0 

a. Hind foot 25 or less. 
b. Tail less than 150. 

c. Tail shorter than head and body. 

d. Ears very large, longer than hind foot. Mexico P. bulhitus (p. 183) 

dd. Ears moderate, shorter than hind foot. Mexico and northward. 
c. Size very small ; hind foot 15-19; tail usually less than 60. 

1. Habitat Florida and Georgia P. polionotus (p. 10.°.) 

2. Habitat Texas to Canada. 

P. maniculatus (pallesccns, bairdi, etc.) (p. 37) 
ee. Size larger; hind foot 10-25; tail usually more than 60. 
/. Total length less than 210 ; hind foot less than 25. 

g. Tail usually very sharply bicolor and pe'nicillate ; white spot at 
anterior base of ear present or absent ; palatine slits usually 
long and nearly parallel-sided. 
/. Rostrum longer (nasals about 11); no white spot at anterior 

base of ear. Mountains of Mexico P. melanotic (p. 109) 

2. Rostrum shorter (nasals usually less than 11) : white spot at 

base of ear present or absent-- P. maniculatus (p. 37 i 

gg. Tail less distinctly bicolor. slightly or not at all penicillate ; no 
white spot at anterior base of ear. 

1. Size averaging larger. Southern United States. 

P. gossypinus (p. 135) 

2. Size averaging smaller. United States, southeastern Canada, and 

Mexico P. leucopus (p. 112) 

ff. Total length more than 210 ; hind foot about 25 P. hylocetea (p. 159) 

cc. Tail equal to or longer than head and body. 
(/. Tail uniform black or brownish all around. 

e. Tail scaly and nearly naked P. allophylus (p. L'06» 

ee. Tail soft-haired and penicillate. 

1. Size larger; hind foot 23-25 P. lophurus (p. 192) 

8. Size smaller; hind foot 21 P. simulatus (p. 193) 

(/(/. Tail more or less bicolor. 

e. Skull with supraorbital border more or less beaded or at least elevated ; 
tail usually irregularly blotched below. Tropical Mexfco and Guatemala. 

f. Habitat Peninsula of Yucatan P. i/ucatanicus (p. 211) 

ff. Habitat south and east of Yucatan. 

/. Supraorbital bead well developed with a distinct sulcus on inner 

side. Western Mexico P. banderanus (p. 207) 

2. Supraorbital border slightly beaded. Southern Mexico and Guate- 
mala P. mexicanus (p. 198) 

ee. Skull with supraorbital border sometimes sharp-angled but never de- 
cidedly beaded nor elevated. Alaska to Guatemala. 
/. Habitat highlands of Chiapas and Guatemala. 

/. Tail clothed with soft hairs and decidedly pencilled ; pelage soft 
and dull P. lophurus (p. 192) 

"Distinguishing from Baiomys and Ochrotomys. 

6 Distinguishing from Podomys. 

''Distinguishing from Baiomys and Haplomylomys. 

d Distinguishing from Haplomylomys. 

' Distinguishing from Megadontomys. 

f Distinguishing from Ochrotomys. 

9 For explanation of keys see p. 23. 


ft. Habitat north of Chiapas. 

g. Ears relatively large ; ear from notch in dry skin 18-25. 
h. Tarsal joints white like upper side of hind foot. 

P. polius (p. 177) 
hh. Dusky of hind leg reaching tarsal joint and more or less ex- 
tended on it, or, if not, then hind foot less than 25. 

1. Ears larger; rostrum shorter (nasals about 10 1 : zygomata 

more squarely elbowed ; audital bullae larger. Western United 
States and Mexico P. truei (p. 105) 

2. Ears smaller; rostrum longer (nasals about 11); zygomata 

more compressed anteriorly ; audital bullae smaller. West- 
ern United States P. nasutus (p. 176) 

gg. Ears smaller; ear from notch in dry skin 18 or less. 
h. Hind foot 23 or more. 

i. Habitat United States?-' Alaska, and Canada. 

j. Tail about equal to or only slightly longer than head and 
body, usually less than 90. Habitat east of 110th 
/. Size averaging larger ; color darker. Habitat chiefly 

east of the 97th meridian P t/ossi/pinus (p 135) 

2. Size averaging smaller ; color paler. Habitat chiefly 

west of the 97th meridian P. Icucopus (p. 112) 

;';'• Tail always longer than head and body, usually more 
than 90. Habitat chiefly west of the 95th meridian. 
k. Habitat north of the State of Oregon. 

1. Size larger ; hind foot at least 25. Habitat islands 

off coast of Alaska and British Columbia. 

P. sitkensis (p. 101) 

2. Size smaller; hind foot 23-25. Habitat Alaska, 

Canada, and Washington. 
P. maniculatus (oreas, macrorhinus, etc.) i p. 37) 
kk. Habitat south of the State of Oregon. 

P. ooylci (p. 141) 
ii. Habitat Mexico. 

;'. Tarsal joint white like upper side of hind foot. 

P. polius (p. 177) 

//. Dusky of hind leg reaching to and often more or less 

over tarsal joint. 

k. Tail usually less than 90, rather finely haired and 

slightly or not at all penicillate ; principal color 

ranging from pale fawn to dusky brownish, seldom 

bright buff or tawny P. Icucopus (p. 112i 

kk. Tail not less than 90, usually more than 100, a little 
more coarsely haired and usually more decidedly 
penicillate ; principal color often brighter buff or 

1. Tail relatively longer ; hind foot 23-25. 

P. boylci (p 141) 

2. Tail relatively shorter ; hind foot rarely less than 

25 P. hylocetes (p. 159 i 

hh. Hind foot not more than 23. 

i. Tail about equal to or only slightly longer than head and 
body, usually less than 90. 
/. Tail very sharply bicolor and slightly penicillate ; with or 
without a white spot at anterior base of ear. 

/'. maniculatus (p. 37) 
//. Tail less sharply bicolor and slightly or scarcely penicil- 
late ; without a white spot at anterior base of ear. 

1. Size averaging larger : color usually darker. Habitat 

Austroriparian zone of southern United States. 
P. gossypinus (p. 135) 

2. Size averaging smaller ; color usually paler. South- 

eastern Canada to southeastern Mexico. 

P. Icucopus i p. 112) 
ii. Tail always longer than head and body, usually more than 90. 
;. Habitat United States, Canada, Alaska, and Lower Cali- 


fc. Tarsal joints white like upper side of hind foot. 

p. pectoralia (p. 160) 
fcfc. Dusky of hind leg extending to and more or less over 
tarsal joint. 

I. Proximal half of sole of hind foot hairy; tail closely 

haired, sharply bicolor, and slightly penicillate ; 
with or without white spot at anterior base of ear. 
Chiefly northern or coastwise 

P. maniculatus (p. 37) 

II. Proximal fourth or less of hind foot hairy ; tail 

loosely hairy and penicillate ; without white spot 
at anterior base of ear. Chiefly southern and in- 
/. Size larger; skull heavier; greatest length of skull 

* 27 or more P. boylei (p. 141) 

,?. Size smaller ; skull lighter : greatest length of skull 

26 or less P. crinitus " (p. 229; 

jj. Habitat Mexico (except Lower California). 

/.-. Dusky of hind leg extending to and more or less over 
tarsal joint. 
/. Size larger ; tail relatively shorter ; maxillary tooth- 
row usually 4 or more P. boylei (p. 141) 

2. Size smaller ; tail relatively longer ; maxillary tooth- 

row usually less than 4 P. pectoralia (p. 160) 

kk. Tarsal joint white like upper side of hind foot. 
/. Size large ; hind foot more than 23. 

P. polius (p. 177) 
2. Size smaller ; hind foot less than 23. 

P. pectoralia (p. 160) 

lib. Tail more than 150 P. mekisturus (p. 189) 

an. Hind foot 2."i or more. 

b. Habitat entirely south of Canada. 

c. Tail rather short, not more than 90 P. yossypinus (p. 135) 

cc. Tail always more than 90. 

<l. Forearm and forefoot blackish or partly so to base of digits. 

P. melanocarpus (p. 216) 
dd. Dusky of forearm not extending beyond carpal joint. 
e. Size very large ; hind foot 30 or more. 

/. Total length more than 300 /'. zarhynchus (p. 217) 

ff. Total length less than 300. 

;/. Supraorbital border more or less beaded. Habitat Oaxaca and 

Guerrero P. megalops (p. 213 1 

yg. Supraorbital border not beaded. 
/. Larger. Habitat Chiapas and Guatemala. 

P. guatemaleneia (p. 193) 

„'. Smaller. Habitat Costa Rica and Panama P. nudipes (p. 195) 

cc. Size smaller; hind foot less than 30. 

f. Tarsal joint white like upper side of hind foot P. polius (p. 177) 

ff. Dusky of hind leg extending at least to tarsal joint. 

;i. Habitat Costa Rica and Panama /'. nudipes (p. 195) 

.'/'/. Habitat north of Costa Rica. 

h. Ear from notch in dry skin not more than 19. 

i. Dusky of hind leg extending over upper side of hind foot 
at least halfway to base of toes. 
j. Skull with a slight supraorbital bead. 

1. Size smaller ; maxillary toothrow less than 5. 

P. mexicanus (p. 198) 

2. Size larger ; maxillary toothrow 5 or more. 

P. meyalops (p. 213) 
jj. Skull without bead. 

fc. Color chiefly dusky ; tail blackish all around or 
at least with basal part of underside some- 
what dusky. 

1. Smaller; tail less than 120 P. lepturua (p. 190) 

2. Larger: tail more than 120 P. furvus (p. 196) 

" This species belongs with the subgenus Haplomylomys, but as it is somewhat con- 
nectant and easily misplaced, it is included in this key as well as in that to Haplomy- 



kk. Color chiefly tawny or ochraceous ; tail sharply 

ami evenly bicolor P. boylei (p. 141) 

ii. Dusky of hind leg not extending halfway to base of toes. 
;. Supraorbital border slightly to strongly beaded, or, if 
not, then tail not evenly bicolor. 

k. Size smaller ; hind foot not more than 20. Penin- 
sula of Yucatan P. yucatanicus (p. 211 » 

kk. Size larger ; hind foot 20-30. 

/. Tail blackish all around P. megalopa (p. 213) 

U. Tail blotched with whitish on underside or 
sometimes evenly bicolor. 
m. Size larger; maxillary toothrow 5 or more. 
P. furvus (p. 196) 
mm. Size smaller; maxillary toothrow less 
than 5. 
/. Supraorbital border strongly beaded (ex- 
cept in subspecies angelensis) . West- 
ern Mexico north of the Isthmus of 
Tehuantepec_P. banderanus (p. 207) 
2. Supraorbital border slightly beaded. 
Southern and eastern Mexico and 

Guatemala P. mexicanus (p. 198) 

}j. Supraorbital border often sharp-angled but not beaded ; 
tail evenly and usually sharply bicolor. 

7;. Total length 240 or more P. oaxacensis (p. 158) 

kk. Total length less than 240. 

1. Tail relatively longer ; hind foot 23-25. 

P. bui/lei (p. 1411 

2. Tail relatively shorter; hind foot rarely less than 

25 P. hylocetes (p. 159) 

hh. Ear from notch in dry skin more than 19. 

i. Supraorbital border slightly beaded or at least somewhat 

j. Tail less than 120. Guatemala P. ultilaneus (p. 197) 

jj. Tail more than 120, or, if not, then habitat north of 


k. Sides of face chiefly grayish ; tail not less than 130, 

usually more than 140 ; tail evenly bicolor (except 

in P. xenurus, confined to the State of Durango). 

1. Tail evenly (not always sharply) bicolor. 

P. melanophrys (p 184) 

2. Tail dusky brownish all around except a \ rly 

defined whitish line on under side. 

P. xenurus (p. 188) 

kk. Sides of face chiefly tawny, ochraceous, or dusky ; 

, tail entirely dusky, irregularly blotched below, or 

evenly bicolor. 

1. Size larger ; maxillary toothrow 5 or more ; brain- 

case broad ; pelage usually long. 

/'. megalops (p. 213) 

2. Size smaller ; maxillary toothrow less than 5 ; 

braincase usually narrower ; pelage usually 

short -/'. mexicanus (p. 198) 

ii. Supraorbital border not beaded nor elevated. 

1. Tail blackish or blotched with whitish below ; nasals ex- 

panded anteriorly —P. furvus (p. 196) 

2. Tail evenly bicolor ; audital bullae rather large. 

/'. ilifficilis (p. 178) 
fob. Habitat islands off the coast of Alaska and British Columbia__P. sitkensis (p. 101) 

Key to subspecies of Peromyscus maniculatus. 

a. Habitat Alaska and Canada. 

b. Habitat east of the 100th meridian. 

c. Habitat islands off coast of Nova Scotia and New Brunswick. 

1. Color grayer; tail longer. Grand Manan Id P. m. argentatus 

2. Color browner; tail shorter. Magdalen Ids P. m. eremus 


(■<■. Habitat mainland. 

</. Tail shorter, averaging loss than 00 ; hind foot rather large. Hudsonian 

zone, Labrador to Hudson Bay, etc /'. marUculatua 

dil. Tail longer, averaging more than 90. 

/. Color grayer. Nova Scotia, New Brunswick, etc P. m. abietorum 

2. Color more tawny or huffy. Southern Ontario and Quebec--/', in. gracilis 
bb. Habitat west of the 100th meridian. 

C. Tail about equal to or shorter than head and body, usually less than 90. 
il. Color darker. Chiefly forested regions north and west of Great Plains. 
c. Color very dark. Islands and coast of British Columbia. 
/. Size smaller ; hind foot 19-21 ; lateral line less prominent. 

P. m. itustmis 
.;. Si/.e larger; hind foot 21-22; lateral line more prominent. Saturna 

Island P. »i. saturatus 

ec. Color somewhat paler. Chiefly east of the coast ranges. 

f. Skull longer ; braincase wider. Chiefly southern British Columbia. 

P. m. ar'temisiae 
ff. Skull smaller; braincase smaller. Northwest Canada — P.m. arcticus 
dil. Color paler, usually chiefly bright ochraceous buffi. Greal Plains of Sas- 
katchewan, etc P. in. nebriiffcensis- 

cc. Tail longer than head and body, usually more than 90. often more than 100. 
il. Size larger ; hind foot 24—25. Coast of northern British Columbia and 

Alaska P. m. macrorhinus 

dil. Size smaller; hind foot 21-24. 

e. Tail and ears averaging longer. Southern British Columbia_-P. m. orcas 
ee. Tail and ears averaging shorter. Northern British Columbia and Alaska. 

f. Color more grayish. Headwaters of Yukon River P. m. algidus 

ff. Color more brownish. Coastal. 

/. Skull lighter; rostrum longer. Alaska P. m. hylaeus 

2. Skull heavier; rostrum shorter. Queen Charlotte Islands. 

P. m. kicni 
aa. Habitat United States and Mexico. 
b. Habitat United States. 

c. Habitat east of the Mississippi River. 

d. Tail long, always more than 80, usually more than 90. 

e. Color more grayish. Eastern Maine P. m. abietorum 

ee. Color more brownish or dusky. Northern States and Appalachian 

1. Size larger ; dark dorsal area less distinct. Minnesota to New Hampshire. 

P. in. gracilis 

2. Size smaller ; dark dorsal area more distinct. Western Pennsylvania 

to northern Georgia P. vi. nubiterrae 

dil. Tail 70 or less. Mississippi Valley P. m. bairdi 

cc. Habitat west of the Mississippi River. 

(7. Size smaller ; hind foot rarely more than 19 ; tail rarely more than 60 ; 
greatest length of skull 22-25. 

e. Size very small; hind foot 15-17. Texas P. m. pallescens 

ee. Size larger; hind foot 18—20. Chiefly north of Texas. 

/. Color chiefly dark brown or blackish P. m. bairdi 

ff. Color chiefly ochraceous buff. 

1. Size smallerl P. m. luteus 

2. Size larger ' P. m. nebrascensis 

dd. Size larger; hind foot rarely less than 20; tail 55-12(1 ; greatest length of 

skull rarely less than 25. 
e. Tail longer, averaging more than 90, frequently more than 100. 

1. Size larger; hind foot 22-24. Cascade Mountains and coast of Wash- 

ington P. m. orean 

2. Size smaller; hind foot 21-22. Coast of Oregon and northern Cali- 

fornia P. in. rubidus 

ee. Tail shorter; averaging less than 90, usually less than 80. 
f. Color paler, ochraceous buff or vinaceous predominating. 

y. Tail averaging shorter. Chiefly east of the Rocky Mountains. 
1. Color more buffy. Northern Texas to central Montana. 

P. in. nebrascensis 


2. Color more vinaceous. Western Texas and southern Mexico. 

P. lit. blandus 
gg. Tail averaging longer. Great Basin region and southeastern 

California P. m. sonoriensis 

ff. Color darker ; dusky, dark brown, or tawny ochraceous predominating. 
g. Color very dark. Chiefly coast of Puget Sound. 

/. Size larger ; tail relatively shorter ; skull larger and heavier. 

San Juan Island P. m. hollisteri 

2. Size smaller ; tail relatively longer ; skull small and light. 

P. in. austerus 
gg. Color somewhat paler. Chiefly Rocky Mountain region and Cali- 
fornia (except northwest coast and eastern desert regions). 
ft. Size larger; skull broader and heavier; nasals usually 11 or 
more. Eastern Washington, Idaho, Montana, and Wyoming. 

P. m. artemisice 
ftft. Size smaller; skull lighter; nasals usually less than 11. 

i. Color more tawny ochraceous, especially in winter pelage. 
Southern Rocky Mountains, Colorado, Utah, Arizona, and 

New Mexico P. m. rufinus 

it. Color more dusky, except in worn pelage. California. 
/. Averaging smaller and paler. Mainland of California. 

P. m. gambeli 
jj. Averaging larger and darker. Santa Barbara Islands. 

J. Smaller; tail and ears shorter P. m. dementis 

2. Larger ; tail and ears longer P. m. catalinm 

bh. Habitat Mexico. 

c. Habitat mainland and islands of Lower California. 

d. Size larger ; hind foot 20-23 ; greatest length of skull usually more than 20. 
Chiefly insular. 
e. Color decidedly grayish, chiefly pale ecru drab. San Roque Island. 

P. m. cineritius 
ee. Color less grayish, chiefly buffy or ochraceous, more or less mixed with 

f. Color darker. Coronados and Todos Santos Islands P. m. dubius 

ff. Color paler. 

/. Size smaller. San Geronimo, Natividad, and San Martin Islands. 

P. in. geronimensis 
2. Size larger. Magdalena Island and adjacent mainland. 

P. m. magdalenae 
dd. Size smaller ; hind foot 19-20 ; greatest length of skull usually less than 
26. Chiefly mainland of Lower California (except margaritae. ) 
e. Color darker, usually with considerable dusky mixture. Northwestern. 

P. m. gambeli 
ee. Color paler, chiefly pinkish buff or ochraceous buff. 

/. Very pale, chiefly pale pinkish buff. Margarita Island. 

P. m. margaritae 
ff. Not so pale, chiefly ochraceous buff. Mainland of Lower California. 

1. Paler, usually with buffy shades toned down by whitish. Southern 

and central Lower California P. in. coolidgei 

2. Not so pale, usually with buffy shades entirely predominating. 

Northeastern P. m. sonoriensis 

<c. Habitat continental Mexico (i. e., all except Lower California). 

d. Color paler, chiefly buffy ochraceous or pale vinaceous ; size slightly smaller ; 
hind foot averaging less than 22. Chiefly northern. 

1. Size slightly smaller; tail shorter, averaging less than 70; color more 

vinaceous. Chiefly east of the Sierra Madre P. in. blandus 

2. Size slightly larger; tail longer, averaging more than 70; color more 

buffy. Chiefly west of the Sierra Madre P. m. sonoriensis 

dd. Color darker, chiefly russet or dusky : size slightly larger : hind foot usually 
22 or more. Chiefly southern. 

1. Color more dusky P. hi. labevula 

2. Color more rufescent '. P m. faints 



(PI. II, fig. 1.) 

Hesperomys maniculatus Wagner, Wieg. Archiv. f. Naturgesch., XI (1), p. 148, 

[Hesperomys] arctictts Sauss., Cones, Monogr. N. Am. Rod., p. 67, 1877 — nomen 

Peromyscus canadensis umbrinus Miller. Proc. Bost. Soc. Nat. Hist., XXVIII, 

p. 23, April, 1897 — Peninsula Harbor, Ontario. 
Peromyscus maniculatus lianas. Am. Nat.. XXXII, p. 400, 1898. 

Type locality. — Labrador; doubtless one of the old Moravian 
settlements on the northeast coast : specimens from Nain used for 
present diagnosis. 

Geographic distribution. — ITudsonian zone of northeastern Canada, 
from the northeastern coast of Labrador to the west side of Hudson 
Bay and smith to the border of the Canadian zone to meet the range 
of P. in. gracilis. 

Characters. — Size medium; tail moderately long, about half the 
total length or slightly more: coloration regular, median dorsal region 
somewhat contrasted; under side of hind feet hairy except on pads 
and spaces between them; tail well haired, sharply bicolor and dis- 
tinctly penciled. 

Color. — Adult in August : Sides and lateral upperparts dark brown 
(Mars brown), tinged with fawn; median dorsal region darker 
(mummy brown), beginning behind shoulders and extending with 
decreasing width to base of tail; orbital region and base of whiskers 
blackish; ears dusky with pale edges; preauricular lanuginous tuft 
with a few white hairs; underparts white, not entirely concealing 
plumbeous undercolor; feet Avhite; tail sharply bicolor, brownish 
black above, white below. Adolescent pelage: Head, sides, and 
lateral upperparts sepia produced by mixture of black and shades of 
buff; median dorsal region and thence to base of tail black with only 
slight admixture of lighter: tail intense black above; ears black or 
blackish outside, whitish inside, edges sharply white; otherwise as in 
adult. Young in first coat : General color slate gray, overlaid with 
white on underparts.' 7 

Skull. — Size larger than in P. m. gracilis/ braincase rather broad 
and flattened, shallower than in gracilis or arcticus; nasals longer and 
narrower than in arcticus; rostrum light; palatine slits rather long 
and nearly parallel-sided. 

"Description based on series of well-made skins collected by W. E. Clyde 
Todd in summer of 1901 for the Carnegie Museum of Pittsburg, supplemented 
by a number of flat and otherwise poorly made skins (now in the Museum of 
Comparative Zoology) collected by the Moravians for J. D. Sornborger, who 
kindly loaned them for study. 


Measurements. — Average of adults from Xain and Windsor Har- 
bor, Labrador: Total length 179 (174-198); tail vertebra' 84 (75- 
95); hind foot 21 (19-23). Of 5 adults from Oxford House, Kee- 
watin: 188.8 (185-193) ; 93 (88-95) ; 20. 

Type specimen. — A specimen having every claim to acknowledg- 
ment as the type of this species is in the Zoologischer Staats-Samm- 
lung of Munich, Bavaria, where I was permitted to examine it 
through the courtesy of Professor Hertwig and his assistant, Doctor 
Leisewitz. An early label attached to it has the following data : 
" Hesperomys maniculatus Wagn. Dr. Barth dst 1844. Labrador." 
The pelage is considerably faded and the specimen, although now 
removed from its stand, is still in mounted posture and has the wires 
and glass eyes of an exhibition specimen. Otherwise it is in good 
condition and all its general characters are obvious, as sharply bicolor 
and slightly penicillate tail, white margined ears, soft pelage, and so 
on. No skull accompanies the skin. The hind foot measures 20.5 mm., 
and the tail, which is intact but shrunken over the vertebra?, measures 
G4 mm. 

Remarks. — This was the first to be named and almost the last to be 
recognized of a large group of inosculating forms — the largest and 
most remarkable of the genus, and perhaps of American mammals. 
Its distribution is wider and the number of intergrading forms and 
of individuals is greater than in any similar group of mammals 
known. From typical maniculatus, development may be traced step 
by step absolutely without break through all the numerous subspecies. 
Throughout the group many interesting problems of distribution and 
development, are presented; these are discussed so far as space will 
permit in connection with the descriptions of the forms concerned. 
Typical maniculatus is most similar to subspecies arcticus, merely 
having a slightly longer tail and slight cranial differences. Speci- 
mens from the Hudson Bay region, though referable to maniculatus, 
approach arcticus and gracilis. Typical maniculatus differs from 
gracilis in shorter tail, darker color, greater extent of dusky on dor- 
sum, and in cranial characters, notably broader, natter braincase. 
From arcticus, it is distinguished by longer tail and by average cra- 
nial characters, as wider braincase, and longer, narrower nasals. 
Specimens of gracilis from Godbout and Lake Edward. Province of 
Quebec, are almost typical, showing only slight tendency toward 

Specimens from the north shore of Lake Superior described under 
the name umbrinus seem best referred to maniculatus. A large series 
from Isle Royale, Michigan, is almost like series from the Hudson 
Bay region and can scarcely be referred to gracilis. Others from 
immediately south of Lake Superior, however, are longer tailed 
and lighter colored and are indistinguishable from specimens from 


northern New York. These are taken as representing typical 
gracilis. The type of gracilis, supposed to have come from Michi- 
gan, has such a long tail that presumably it came from the southern 
or central part. of the State. 

/Specimens examined. — Total number 239, from localities as fol- 

Keewatin:' 1 Echimamish River, 17; Hayes River, 25 miles above York 
Factory, 1 ; Hill River, 9 ; Norway House, 9 ; Oxford House, 13 ; 
Oxford Lake, 8; Pine Lake, 8; Robinson Portage, 15; Sea River 
Falls, 4; Shamatawa River, 4; Steele River, 2; Trout Falls, 1; York 
Factory, 3G. 

Labrador: Great Whale River, 1 ; Hopedale, 3 ; Labrador, 2 ; Makkovik, 5 : 
Nain, 18; Rama, 2; Windsor Harbor, 18. 

Michigan: ° Isle Royale, 55. 

Ontario: a Moose Factory, 1; Peninsula Harbor, 7. 


(PI. II, fig. 5; PI. VII, fig. 12: PI. VIII, fi«. 6.) 

Hcspcromys gracilis Le Conte, Proc. Acad. Nat. Sci. Pbila., VII, p. 442, 1855. 
Bitomya americanus canadensis Miller, Proc. Biol. Soc. Wash., VIII, pp. 55-09, 

June 20, 1893— Peterboro, N. Y. • 
Peromyscus gracilis Lyon and Osgood, Bull. No. 62, TJ. S. Nat. Mus., p. 131, 

Jan. 27, 1909. 

Type locality. — Michigan. 6 

Geographic distribution. — Northeastern United States and south- 
ern Canada from northern Minnesota east through northern Wiscon- 
sin, Michigan, Ontario, Quebec, New York, and western New Eng- 
land. Canadian zone. 

Characters. — Similar to manicidatus, but color slightly less clouded 
with dusky; hind foot smaller; tail longer, actually and relatively; 
skull smaller and narrower. Superficially similar to noveboracensis, 
but tail longer, more distinctly penciled, and more sharply bicolor; 
pelage softer; skull more slender; molar teeth smaller. 

Color. — Unworn pelage (fall and winter) : Ground color varying 
from russet through cinnamon to isabella color, more nearly russet on 
flanks and posterior part of back, becoming grayer and more nearly 
isabella color across shoulders and on top of head ; dusky mixture 
moderate throughout, somewhat concentrated in middle of back ; gen- 
eral effect on sides nearly raw umber, on dorsum same but strongly 
blackish, on shoulders rusty hair. brown; ears blackish, narrowly 
edged with whitish, often with a few white hairs at anterior bases; 
narrow orbital ring and spot at base of whiskers blackish ; underparts 

"All approaching gracilis and arcticus. 

6 In the absence of proof to the contrary, Michigan may be taken as the type 
locality of gracilis, in accordance with the statement of the original descrip- 
tion and notwithstanding the queries on the labels of the type specimeu. 


white; feet white, forearm usually slightly dusky, ' ankles ' dusky ; 
tail blackish above, w T hite below. Worn pelage (spring and early 
summer) : Similar to unworn pelage, but dusky mixture more or less 
eliminated or changed to shades of cinnamon which are scarcely con- 
trasted with the ground color; general effect dull cinnamon on sides, 
shading to russet or Mars brown on dorsum; markings about face, 
ankles, and upper side of tail brownish instead of blackish. Ado- 
lescent pelage: General effect of upperparts broccoli brown, hair 
brown or nearly Isabella color. Young in first coat: General effect 
of upperparts hair brown to sepia, usually somewhat blackish or 
slaty in middle of back. 

/Skull. — Similar to that of maniculatus, but smaller and narrower ; 
braincase not so broad nor so flattened. • Also similar to that of 
arcticus, but narrower, with zygomata less widely ' elbow 7 ed ' ante- 
riorly and nasals longer and narrower. Slightly similar to that of 
noveboracensis, but braincase narrower, nasals longer, maxillaries 
less bulging in front of infraorbital foramen, anterior part of zygo- 
mata lighter, palatine slits longer and more nearly parallel-sided; 
molar teeth smaller. 

Measurements. — Two adults from Porcupine Mountains, Onton- 
agon County, Mich.: Total length, 192, 178; tail vertebra?, 95, 114; 
hind foot, 22, 20. Average of 9 adults from Tower, Minn., 186 
(174-200), 90 (80-104), 19.8 (19-21) ; of 10 adult males from Peter- 
boro, N. Y., 190 (176-20G), 96.8 (85-108), 21.4 (20.8-21.8); of 10 
adult females from Peterboro, N. Y., 178 (171-200), 89 (84-100), 20.7 

Type specimen. — No. \%\%\ U. S. National Museum evidently is the 
type of Hesperomys gracilis Le Conte. It agrees perfectly with the 
original description and has passed as the type for more than thirty 
years. It bears several labels, among them, one in the hand of Doctor 
Cones, as follows : "Hesp. gracilis. Le Conte 's type specimen. Wis- 
consin? Ohio? Michigan?" In the Museum catalogue under No. 
10292 occurs the remark " Dry type of gracilis " (entry made in 1872). 

The specimen is in poor condition. The skin consists of the 
anterior and posterior parts connected by thread and cotton. The 
left hind foot and the tail are present, and also the ears, which are in 
fair condition. The tail measures approximately 95 millimeters — 
the tip has been broken off. The skull has been removed and is 
sufficiently complete to show important characters. The posterior 
part has been broken away, including the greater part of the brain- 
case and the sphenoid and occipital regions. The tips of the nasals 
are slightly broken. The teeth and both mandibles are intact. 

Remarks. — Under the name canadensis, this form has become well 
known in recent years. It is the long-tailed mouse of the northeastern 
United States as opposed to the shorter tailed noveboracensis with 


which it has often been confused. It is really quite distinct from 
noveboracensis, and adult specimens of the two are readily distin- 
guishable by both external and cranial characters. Immature or 
poorly prepared specimens, however, are sometimes difficult to deter- 
mine. Although living in the same general localities, gracilis and 
noveboracensis are nearly always confined to different local habitats, 
gracilis showing preference for the colder, more moist places, or deep, 
mostly coniferous, woods; noveboracensis for the warmer, dryer, more 
open country, or deciduous woods. 

Like the other members of the maniculatus series, gracilis grades 
into surrounding forms by scarcely perceptible degrees. On the 
north and east it meets maniculatus and abietorum; on the northwest, 
areticus; and on the south, nnbiterrce. Large series from the Hudson 
Bay region referred to maniculatus plainly approach areticus, being 
darker and shorter tailed than gracilis. They so nearly combine the 
characters of maniculatus, gracilis, and areticus that without violence 
they might be placed with any of the three. In the same way, speci- 
mens from New Hampshire approach abietorum, and others from 
Pennsylvania tend toward nubiterrm. Even specimens from Peter- 
boro, N. Y., the type locality of ' canadensis ' show slight tend- 
ency toward abietorum, but they are much nearer to gracilis, and as 
there is scarcely room for three forms in this series, canadensis is not 

The application of the name gracilis to this form seems incon- 
testable (regardless of the supposed type specimen, which unquestion- 
ably belongs to this form), because the measurements given in the 
original description could not possibly apply to noveboracensis. The 
original description is as follows: 

Hair dark slate-color above, a little tipped with brown, cheeks, line above 
the mouth, chin, throat, and body beneath white, allowing the dark color of the 
lower part of the hair to shine through in such a manner as to cause these 
parts to appear grey. Outer side of fore legs brownish, thighs slate colored 
both above and beneath, feet pale grey, nearly white. Head narrow, nose some- 
what pointed, ears large, open, narrowly edged with whitish. Tail longer than 
head and body. 

Length 3.S in. Tail 4 in. * * * 

Inhabits Michigan ; Prof. Baird. 

Specimens examined. — Total number 234, from localities as fol- 

Massachusetts: Mount Graylock, 2. 

Michigan: Park Siding, 5; Porcupine Mountains, 4 ; a Suny, 4. 
Minnesota: Bridgman, 3; Minnesota, 4; Tower, 14; Two Harbors, 2. 
New Hampshire: Dublin, 1; Mount Washington, 16; Ossipee, 3. 
New York: Alder Creek, 3; Catskill Mountains, 13; Elizabethtown, 2; 
Lake George, 1 ; Locust Grove, 10: Mountain View, 3; Peterboro, 68; 
Piseeo. 4. 

°Coll. Univ. of Michigan. Submitted for examination by Prof. C. C. Adams. 


Ontario: Algonquin Park, 11; Bracebridge, 1 ;" Deer Park, o; a Grand 
Bend, 1; Gravenhurst. 2; Michipicoten Island, Lake Superior, 4; 
North Shore, Lake Superior (Agassiz), 1; Port Franks, 3; Sand 
Lake, 1. 

Quebec: Godbout, 2; Lac aux Sables, 3; Lake Edward, (5; Murray Lay, 11. 

Vermont: Burlington, 1; Mount Mansfield, 9. 

Wisconsin: Eagle Liver, 7 (approaching inaniculatus ) . 


Peromy&cm canadensis abietorum Bangs, Proc. Biol. Soc. Wash., X, 49-50, 
Mar. 9, 1896. 

Type locality. — James River, Nova Scotia. 

Geographic distribution. — Nova Scotia and neighboring parts of 
eastern Canada ; west to central Maine. 

General characters. — Similar to P. m. gracilis, but paler and graver. 

Color. — No. 2201 Bangs Collection, in slightly worn summer pelage : 
Similar to P. m. gracilis, but paler and grayer; upperparts and sides 
almost uniform drab, with very fine dusky grizzling and scarcely any 
indication of a dark dorsal stripe ; orbital region and base of whiskers 
with weak dusky markings; tail brownish black above, white below; 
underparts white. Full winter pelage (No. 1473 U. S. National Mu- 
seum) : Almost as in same pelage of P. m. gracilis, being not grayer, 
but slightly browner; general color bister, with a tinge of fawn color, 
this produced by grizzling of pale fawn color and dusky ; back essen- 
tially like sides; underparts pure snowy white. 

Skull. — Essentially as in P. m. gracilis. 

Measurements. — Type : Total length, 200 ; tail vertebra 3 , 103 ; hind 
foot, 20. Average of 10 adults from Third Mopang Lake, Maine: 
177 (171-187) ; 91.6 (82-97) ; 21 (20-22). 

Type specimen. — No. 2205, Museum of Comparative Zoology. Cam- 
bridge, Mass. 9 adult, Aug. 8, 1894. Formerly same number, 
Collection of E. A. and O. Bangs. Well-made specimen accompanied 
by full data including flesh measurements taken by the collector, C. 
H. Goldthwait. 

Remarks. — The series upon which this form was named consists 
largely of immature specimens, most of which are somewhat over- 
stuffed, causing paleness, which is more apparent than real. It is 
evident, however, that abietorum averages grayer than gracilis, as 
shown by a considerable series from northeastern Maine, which seems 
to be referable to this form rather than to gracilis. Between this 
form and arcticus there is gradual intergradation, arcticus being 
darker and shorter-tailed and abietorum, paler and longer-tailed. 
Between the two there seems to be room for the recognition of only 
one intermediate form. Two names have been proposed, gracilis 

" Collection of Canadian Geological Survey. 


and canadensis, and, although specimens from their respective type 
localities arc not exactly alike, they resemble each other more than 
they resemble cither of the extremes, arcticus and ahietorum. There- 
fore gracilis, the one named earlier, is recognized. 
Specimens examined. — Total number 101, from localities as follows: 

Maine: Big Deer Isle, 1; Blue Hill, 2; Bucksport, 1; Columbia Falls, 1; 

Greenville, 1 ; King and P.artlett Lake, 11 ; Mount Katahdin, 9; Third 

Mopang Lake, 2f> ; Sebec Lake, 1; South Twin Lake, Penobscot 

County, 44: Upton, 2. 
New Brunswick: Arthurette, 1; Gulquac Lake, Victoria County, 3; 

Hampton, 4; Tobique Point. 1: Forks Tobique Point River, 19; 

Tobique River, 4; Trousers Lake, 24. 
Nova Scotia: Digby, 1; Halifax, 1; James River, 17. 
Quebec: Port Daniel, 6; Riviere du Loup, 8; Saint Rose du Degele, 1; 

Salmon Lake, 1. 
Prince Edward Island: Kensington, 2. 


Peromyscus canadensis argentatus M. Copeland and M. L. Church, Proc. Biol. 
Soc. Wash., XIX, pp. 122-123, Sept. 6, 1906. 

Type locality. — Grand Harbor, island of Grand Manan, New 

Geographic distribution. — Island of Grand Manan, New Bruns- 

Characters. — Similar to P. m. ahietorum, but tail averaging slightly 
shorter, and color more grayish, with dusky mixture more copious 
and intense; similar to P. maniculatus, but color decidedly more 

Color. — Unworn pelage: Similar to that of ahietorum, but slightly 
grayer, less buffy; dusky mixture stronger and more intense; sub- 
terminal zone of hairs of upperparts narrower and paler; general 
effect of upperparts varying from drab to broccoli brown and hair 
brown, mid-dorsal region often so mixed with dusky as to produce 
an effect approaching slate gray; underparts white, quite concealing 
slaty undercolor; ears blackish, faintly edged with paler; orbital 
ring and spot at base of whiskers intense blackish; tail sharply 
bicolor, blackish above, white below. 

Ski/IJ. — As in P. maniculatus. 

Measurements. — Average of 23 topotvpes: Total length, 180 
(171-1D4) ; tail vertebrae, 87.8 (82-93) ; hind foot, 21.2 (20-22). 

Type specimen. — No. 168. Collection of Manton Copeland, Taun- 
ton, Mass. $ adult. Sept. 19, 1905. Manton Copeland and Morton 
L. Church. Specimen in good condition. 

Remarks. — This insular form combines to some extent the charac- 
ters of typical maniculatus and ahietorum. though grayer than either. 
It is about the same size as maniculatus and in its grayish coloration 


approaches abietorum. Many adults closely resemble immature ex- 
amples of abietorum. 
/Specimens examined. — Total number 46, all from the type locality. 


Type from Pleasant Bay, Grindstone Island, Magdalen Islands, Quebec. No. 
150223, U. S. National Museum, Biological Survey Collection. 9 adult, 
Aug. 9, 1907. W. H. Osgood. 

Characters. — Similar to P. >n. abietorum, but color darker and tail 
shorter; similar to P. maniculatus, but paler and slightly smaller. 

Color.- — Similar in general to typical maniculatus, but paler 
throughout, yet darker than abietorum. Type in fresh fall pelage: 
Ground color of upperparts russet, uniformly and rather liberally 
mixed with dusky, producing a general effect slightly lighter than 
Prout brown ; concentration of dusky mixture in middle of back com- 
paratively slight; a distinct dusky orbital ring and spot at base of 
whiskers; underparts creamy white; tail sharply bicolor. 

Skull. — Practically as in P. m. abietorum ; somewhat smaller and 
narrower than in maniculatus. 

Measurements. — Type: Total length, 183; tail vertebrae, 83; hind 
foot, 21; ear from notch (dry), 15.7 (15-16). Average of 10 topo- 
types: 181 (172-189) ; 83 (78-90) ; 21. 

Remarks. — This island form differs in color more decidedly from 
P. m. abietorum, which occurs on the mainland of Nova Scotia and 
New Brunswick, than it does from typical maniculatus of Labrador. 
It is in fact nearly intermediate between abietorum and maniculatus, 
being darker than the former and paler than the latter. 

/Specimens examined. — Total number 19, all from the type locality. 


Peromyscus leucopus nubiterrae Rhoads, Proc. Acad. Nat. Sci. Phila., pp. 

187-188, April, 1S9C>. 
Peromyscus canadensis nubiterrae Rhoads, ibid., p. 213, May, 1897. 

Type locality. — Summit of Roan Mountain, North Carolina, alti- 
tude 6,370 feet. 

Geograplih- distribution. — Allegheny and Blue Ridge Mountains 
and adjacent ranges from western Pennsylvania south to western 
North Carolina, and northeastern Georgia. Canadian zone. 

Characters. — Similar to gracilis but slightly smaller; dusky area 
in middle of back broader and better defined. Tail longer than head 
and body : skull quite small ; pelage very soft. 

"The occurrence of P. m. nubiterrae in Georgia is not indicated on the dis- 
tribution map (Plate I), as specimens from that State were not received until 
after the plate was printed. 


Color. — Much as in gracilis bul usually with a broader, better de- 
fined, dusky dorsal area, particularly in unworn pelage. Topotype 
No. 54401 in full winter pelage (January) : Sides of body, head, and 
shoulders russet, thickly sprinkled with blackish, producing a general 
effect approximating Prout brown; back from shoulders to base of tail 
broadly blackish brown, sparingly relieved with russet; underparts 
pure creamy white entirely dominating the slaty basal color; ears 
dusky, rather sharply edged with whitish; small white tufts at an- 
terior bases of ears; a narrow dusky orbital ring and spot at base 
of whiskers; feet white, 'ankles' dusky; tail dusky brownish above, 
white below. Topotype No. 73121 in partly worn pelage (July 20) : 
Sides cinnamon tinged with fawn; back brownish. 

Skull. — Similar to that of gracilis, but averaging decidedly 
smaller; very much smaller and lighter, than in levcopus and gossy- 

Measurements. — Type: Total length 170; tail vertebrae 87; hind 
foot 20.5. Two adult topotypes : 173, 188 ; 93, 98 ; 21, 19.5. 

Type .s- peci m at. — No. 3664 Collection Academy of Natural Sci- 
ences, Philadelphia. $ adult, June 19, 1895. Samuel N. Khoads. 
Specimen in good condition. 

Remarks. — This form is not strongly characterized, but seems 
worthy of recognition, particularly since it is a divergent, or what 
may be called a peripheral development, not standing between any 
two oppositely characterized forms. Its peculiarities, though not 
absolutely constant, are shared by a majority of individuals. The 
skulls from the type locality are variable, perhaps indicating that 
the small size and other characteristics are not as yet thoroughly 
established. The dark color more nearly approaches that of true 
gracilis than it does that of specimens from New York and New 
England, all of which tend more or less toward abietorum. 

Specimens examined. — Total number 175, from localities as follows: 

Georgia: Brasstown Bald, 12. 

Maryland: Bittiuger, G; Finzel, 19; Grantsville, 16. 

North Carolina: Highlands, 7: Pisgah Ridge, Transylvania County, 6; a 

Roan Mountain (4,700-6,300 feet), 36. 
Pennsylvania: Drury Run, 1; Eaglesmere, Sullivan County, 4; King 

Station, Cambria County. 0; Lake Ganoga, Sullivan County, 2; 

Mount Pocono, 2; near Round Island, Clinton County, 2; Summit 

Mills, Somerset County, 19. 
Tennessee: Holston Mountains, 1. 
Virginia: Mount Rogers, 4; Peaks of Otter, 2; Sky land, Page County, 1; 

Tazewell Peak, 1. 
West Virginia: Black Mountain, 5; Cold Knob Mountains, 1; Jobs 

Knob 6; Travelers Repose, 10; White Sulphur. 3. 

" Coll. Biltmore Forest School. 



(PI. I. fig. 2.) 

Hesperomys leucopus arcticus" Mearns, Bull. Am. Mus. Nat. Hist., N. Y. II, 

p. 285, Feb., 1890. 
Peromyseus mania/lulus arcticus Osgood, N. Am. Fauna No. 19, p. 33, Oct., 1900. 

Type locality. — Fort Simpson, Mackenzie, Canada. 

Geographic distribution. — Interior of northwest Canada; from 
southeastern Saskatchewan north along the Mackenzie Eiver at least 
to Fort Norman ; west to the upper waters of the Yukon, and thence 
south to eastern Alberta. Canadian and Hudsonian zones. 

Characters. — Similar to maniculatus, but tail shorter; nasals 
shorter and wider. Similar to gracilis, but slightly more dusky 
throughout; tail shorter: skull broader and heavier. Similar to 
nebrascensis, but decidedly darker, less ochraceous; tail slightly 
longer; skull broader. Similar to artemisiai and oreas, but tail 
shorter; skull shorter and more angular. 

Color. — Unworn pelage (November) : Ground color of upperparts 
isabella color to cinnamon, quite heavily and uniformly mixed with 
dusky, which is slightly or not at all concentrated in middle of back; 
general effect thus produced varying from grayish cinnamon to drab 
or hair brown, much like the adolescent pelage of related forms; 
orbital ring and spot at base of whiskers strongly blackish; white 
hairs in basal ear tufts usually well developed; underparts creamy 
white; tail deep dusky, almost black, above, white below; 'ankles' 
sharply blackish. Worn pelage (April-August) : General effect of 
sides cinnamon, shading into pale russet in middle of back; ' ankles ' 
dusky brownish; tail dusky brownish; otherwise similar to unworn 
pelage. Adolescent pelage : Slightly grayer and more dusky than 
in unworn adult; ground color of upperparts nearly drab: general 
effect hair brown to blackish mouse gray. Young in first coat: 
General effect mouse gray to slate color, often quite blackish in mid- 
dle of back. 

Skull. — Similar to that of gracilis, but averaging larger and 
heavier; nasals wider; infraorbital part of zygomata heavier; entire 
skull shorter relative to its width ; lower lip of foramen magnum 
broader and condyle more sharply notched on each side. The same 
characters in greater or less degree also distinguish it from the 
skulls of nebrascensis, rufinus, artenvisiae, and oreas, the only other 
forms to which it is closely related. 

Measurements. — Average of 25 adults and adolescents from the 
type locality: Total length. 100 (150-172) ; tail vertebrae, 71 (62-78) ; 

°The name arcticus was published as a nomen nudum in 1S7T — cf. Coues, 
Monogr. X. Am. Rod., p. 67. 

66268— No. 28—09 4 


hind foot, 20 (19-21) ; ear from notch (dry), 15.8 (15-16.8). Of 5 
adults from the upper Athabaska River (approaching oreas) : 170 
(168-193) ; 85 (80 91) ; 20. 

Type specimen. — No. 5555, Museum of Comparative Zoology, Cam- 
bridge, Mass. ; formerly No. 4531, U. S. National Museum. $ 
young adult, Sept. 7, 1859. Robert Kennicott. Skin in fair 
condition with all parts intact. Head and neck show slight effect 
of recent moistening, evidently done in removing the skull. Hind 
feet turned under body, but in good condition; tail perfect. Color 
rather paler than in recently collected topotypes, doubtless due to 
fading, which renders the specimen unreliable for close comparisons. 
Skull with zygomata not 'squared' greatly as in older individuals; 
crowns of teeth scarcely worn. Zygomata somewhat broken; basi- 
occipital and sphenoid region cut out in a long rectangle. 

Remarks. — P. m. arctic us is the only member of the genus inhabit- 
ing the great forested region of the interior of northwest Canada. 
Its range in this region is very wide, evidently covering the entire 
Canadian section and entering the Hudsonian at some points. 
Throughout the center of its range it is very constant in character, 
but around the edges it is unstable and intergradation with various 
forms is evident. Its relationships might still be a puzzle but for the 
large series recently secured by the expeditions of Edward A. Preble. 
Specimens from the lower Athabaska River are quite typical, but 
those from the upper river have increasingly longer tails, and certain 
individuals from the extreme headwaters near Henry House, Alberta, 
are almost like areas. The evidence that arcticus as it ranges west- 
ward into the mountains gradually merges with oreas is thus almost 
complete. On the east the chain of intergrades is less complete, but 
sufficient to show that arcticus, as it ranges down the Saskatchewan 
River, intergrades with gracilis or maniculatus. On the south it 
meets nebrascensis, which replaces it on the open plains. Intermedi- 
ates between the two are abundant, a series from Osier. Saskatchewan, 
perhaps containing the greatest number. About the upper waters of 
the Lewes River, of the Yukon drainage, arcticus is found in com- 
pany with algidus and apparently distinct from it, though elsewhere 
the two are connected. Such a state of affairs, however, is not unique, 
as it is found in several other cases in the extraordinary maniculatus 

The interrelations of arcticus, oreas, and artemisiae are extremely 
difficult to understand. Further material from the interior of 
British Columbia will be required before many doubtful points can 
be satisfactorily cleared up. That all three forms intergrade with 

a These western specimens of arcticus are slightly smaller than typical, but 
not sufficiently so to be separable. 


each other, however, and in turn with gambeli, sonoriensis{ etc., is 
scarcely to be doubted. 

Specimen* examined. — Total number 1,043, from localities as fol- 

Alberta: Athabaska Lake (outlet), 15; Athabaska Landing, 22 (5 miles 
above 8; 30 miles above 14) ; Athabaska River, 22 (Brule Rapid .'!. 
Cascade Rapid 1, Crooked Rapid 2, Grand Rapids 5, 60 miles above 
Grand Rapids 3, Mountain Rapid 2, Pelican Rapid 3, 50 miles 
above Pelican Rapid 2. Swift Current 1); Banff, 10; Blindman 
River, 5; Braggs Crossing, 4;« Buffalo Lake, 10; Calgary, 7 (ap- 
proaching nebrascensis) ; Canadian National Park, 15; Canmore, -; 
Crows Nest Pass, 5;« Edmonton, 3 ; a Fish Creek, 3;° Forks Blind- 
man and Red Deer rivers, 7; Fort Chipewyan, 22; Fort McMurray, 
1; Grand Cache River, 6; b Henry House, 26;" Jasper House, <'.;'' 
Miette River, 1 \ a Moose Mountain, 3; Moose River, 4 ;« Muskeg 
Creek, 13 ; b Peace River Landing, 14 ;« Red Deer, 5; Red Deer River, 
15 (approaching nebrascensis) : St. Albert, 1; Slave River, 31 (near 
mouth Peace River 17, Smith Landing 14) ; South Edmonton 
( = Strathcona), 49; Sturgeon River, l.« 
British Columbia: Cariboo, 1; Cheonnee Mountains, 6; Level Moun- 
tain, 3; Raspberry Creek, 10; Shesley River, 3; Telegraph Creek, 
Mackenzie: Fort Norman, 6; Fort Providence, 21: Fort Rae. G3 ; Fort 
Resolution, 100; Fort Simpson, 78; Fort Smith, 39; 00 miles below 
Fort Smith, 2: Fort Wrigley, 2: Great Slave Lake (islands east of 
Fort Resolution), 4; Nahanni River Mountains, 4; mouth Nahauni 
River, 5 ; Willow River, near Fort Providence, 2. 
Saskatchewan: Carlton, 5; Indian Head, 3S; Wingard, 11. 
Yukon: Fifty Mile River, 3; Lewes River, 2; Lake Lebarge, 17; Lake 
Marsh, 8 ; White Horse Rapids, 1. 

Peromyseits areas Bangs, Proc. Biol. Soc. Wash., XII, p. 84, Mar. 24, 1S98. 

Type locality. — Mount Baker Bange (altitude 6,500 feet), British 

Geographic distribution. — Mountains and coast of western Wash- 
ington, north to southern British Columbia, south to Columbia River. 

Characters. — Size rather large (hind foot 22-24); tail very long 
(seldom less than 100, usually more than 110) : color very dark and 
rich. Similar in general to arcticus, but color darker and richer; tail 
and hind foot longer; ears larger. Similar to austerus, but size decid- 
edly larger; color averaging much less blackish; skull larger and 

a Collection of Canadian Geological Survey. 

& Approaching oreas. 

c The majority of this series are intermediate between arcticus and oreas, 
but. a few specimens are almost as long-tailed as oreas. Possibly they are still 
more closely allied to algidus. 


Color. — Unworn pelage: Ground color of upperparts cinnamon to 
russet, slightly paler on anterior half of body; dusky mixture rather 
strong, but not predominating except in middle of back, where it 
shows as a broad, irregular blackish patch; eye with a well-defined 
sooty ring around it; a prominent sooty spot at base of whiskers; 
underparts creamy white; feet white, forearm dusky and tawny, 
'ankles 1 dusky brownish; cars dusky, very narrowly edged with 
whitish; very little or no white at anterior base of ear; tail blackish 
brown above, white below. Worn pelage: Sides bright russet to 
Mars brown; middle of back Mars brown to mummy brown; dusky 
mixture variously eliminated and changed to shades of brownish. 
Adolescent pelage: Upperparts pale cinnamon uniformly mixed 
with dusky, producing a general effect of broccoli brown tinged 
with fawn. 

Skull. — Size slightly larger than in arcticus; nasals, palatine slits, 
and general rostral region longer; infraorbital foramina more com- 
pressed laterally; inferior lip of foramen magnum less distinctly 
notched on either side; general outline of skull more compressed 
anteriorly. Similar to that of austerus, but much larger; nasals and 
palatine slits longer; braincase broader; teeth larger. 

Measurements. — Type and one topotype, respectively: Total 
length, 200 ; 207 ; tail vertebrae, 101 ; 114 ; hind foot, 24 ; 24. Average 
of 10 adults from Mount Rainier, Washington: 203 (194-214); 111 
(105-120) ; 23.2 (22-24) ; ear from notch (dry) 16.6 (15.9-17.1). Of 
12 adults from Neah Bay, Washington: 201 (185-214); 111 
(105-123); 22.8 (22-24). 

Type specimen. — No. 3696 Museum of Comparative Zoology, for- 
merly same number, Collection of E. A. and O. Bangs. $ adult, 
Aug. 29, 1896. A. C. Brooks. Specimen in good condition. 

Remarks. — In length of tail, this form exceeds all other members 
of the manicnlatus group. Although the average length is about 
110 mm., specimens with tails longer than 120 are common, and an 
extreme example from Quiniult Lake. Washington, has a tail meas- 
uring 131 mm. P. m. oreas is not confined strictly to mountainous 
country, but inhabits also the heavily forested lowlands of the Puget 
Sound region. Its relationship to austerus is difficult to understand. 
The case is very similar to that of gambeli and rubidus in California, 
the complications of which may be due either to hybridization or to 
intergradation. It is already known that areas and austerus occur 
together at a number of localities and apparently maintain their 
respective characters. At other places only one form has thus far 

a A single specimen from Teniiio, Wash., appears to represent a peculiar pale 
phase which in worn pelage is pale viuaceous drab. Several like it have been 
examined from monntains near Wenatchee, and from Lake Kichelos. Others 
from Tenino and from Eastoii. near Lake Kichelos, seem to be typical oreas. 


been found, at others extremes of both forms and intermediates occur. 
and at still others intermediates only. There is no environmental 
distinction as in the case of gambeli and rubidus, for oreas and aus- 
terus live under apparently identical conditions. Although only one 
form has been found at the respective type localities of oreas and aus- 
terus, both occur together near by and further collecting may show 
that they do so over a wide area. Specimens which appear to be 
intermediate between oreas and austerus may in reality represent 
special differentiations of the one or the other showing accidental 

As stated elsewhere, oreas appears to intergrade with <ir<-ti<-tis, most 
of the intermediate specimens having been referred to artemisiae. It 
intergrades also with macrorhinus, as proved by specimens from 
River Inlet, British Columbia. Intergradation with rubidus also is 
evident. When intergradation occurs with so many forms even the 
extremes of which are closely similar in general characters, the allo- 
cation of individual specimens or of small series is extremely difficult. 
Specimens from Lake Bennett and the region of the headwaters of 
the Yukon, previously referred to oreas, 11 prove to be separable and 
apparently are most closely related to forms of the Alaskan coast. 
They may be connected with oreas through the interior of British 

/Specimens examined. — Total number, 357, from localities as fol- 
lows : 

British Columbia: Chilliwack Valley. 9; Hope and near Hope, 50; Mount 

Raker Range, 5; Port Moody, 14. 
Washington: Aberdeen, 2; Boulder Creek, 20 ; 6 Boulder Lake, ll; 6 head 
of Cascade River, 7; Chehalis County, 3; near Lake Cushman, 15; 
Easton, 7; Granville, 7; Happy Lake, 42; 6 Kent, 1; Kiehelos Lake, 6; 
Lake Washington, 2; Lapush, 19; Martin, 2; Mount Rainier, 29 
(Longmire Springs 9, Paradise Creek, altitude 5,200 feet, 11) ; 
Mount St. Helens, 2: Mount Vernon. 8; Noah Ray. 4!>; r Quiniult 
Lake, 15; Roy, 1; Shoalwater Ray, 1; North Fork Skokomish 
River, 6; Suez, G; Tenino, 10; 00 miles cast of Toledo, 2; near 
Wenatchee, (aberrant). 


(PL II, fig. 4). 

Peromyscus hylaeus Osgood, Proc. Biol. Soc*. Wash.. XXI, pp. 141-142, June 9, 

Type locality. — Hollis, Kasaan Bay, Prince of Wales Island, 

Geographic distribution. — Islands and coast of southeast Alaska 
west and northwest of the range of P. m. macrorhinus, including 

a North Am. Fauna No. 19, p. 32, Oct., 1900. 
6 May include some specimens of P. m. austerus. 

c Three specimens in this series, although having the large hind foot and long 
tail of areas, have small skulls very similar to those of oust crux. 


Prince of Wales, Kupreanof, Mitkof, and Admiralty islands and the 
mainland coast from Lynn Canal to Frederick Sound. 

Characters. — Color rich and dark, about as in macrorhinus; size 
decidedly smaller. Similar to oreas, but color possibly averaging 
slightly darker and otherwise differing much as keeni docs in having 
smaller ears and shorter tail. Similar to keeni, but skull more lightly 
built ; rostrum longer, more slender. Similar to algidus, but color 

Color. — Practically as in keeni. Worn pelage: Sides varying from 
russet to Mars brown and shading into Mars brown and Prout brown 
on dorsum. 

JSkull. — Very similar to that of oreas; nasals and rostrum aver- 
aging slightly more slender. Similar to that of keeni, but more 
lightly built throughout; rostrum and nasals longer and more slen- 
der; posterior nasal endings usually exceeding premaxillse; infraor- 
bital region lighter. Somewhat similar to that of macrorhinus, but 
decidedly smaller. 

Measurements. — Average of 20 adult topotypes: Total length 198.4 
(101-205) ; tail vertebrae 98 (91-105) ; hind foot 23 (22-23.5) ; ear 
from notch (dry) 15.3 (14.5-16.8). 

Type specimen. — No. 127038 U. S. National Museum, Biological 
Survey Collection. $ adult. May 15, 1903. W. H. Osgood. Speci- 
men in good condition. 

Remarks. — This is the form prevalent over most of the coast 
region of southern Alaska. In general terms it is like keeni, except 
in cranial characters, and both keeni and hylaeus are very similar to 
oreas except in respect to their shorter ears and tails. All are de- 
cidedly smaller than macrorhinus and sitkensis. The form from the 
Queen Charlotte Islands, keeni, so far as known, is the only well- 
developed insular form north of Puget Sound, all those from the 
various islands of the Alexander Archipelago, with the exception 
of sitkensis, being too slightly or not at all differentiated. P. tn. 
hylaeus probably intergrades with macrorhinus in the vicinity of 
Frederick Sound, as indicated by the slightly increased size of speci- 
mens from Mitkof Island. Intergradation with algidus takes place 
in the region of Lynn Canal. 

Specimen* examined. — Total number, 103, from localities as fol- 

Alaska: Glacier Bay, 2; Juneau, 10; Kasaan Bay, Prince of Wales 
Island, 63; near Killisnoo. Admiralty Island, ."4: Lindenburg Penin- 
sula, Kupreanof Island, 1G; Petersburg, Mitkof Island, 13; Taku 
Harbor, 5. 


(PI. II, fig. 8.) 

Sitomys keeni Rhoads, Proc. Acad. Nat. Sci. Phila., pp. 25S-259, Oct. 23, 1S94. 
P[eromyscus] keeni Bangs, Am. Naturalist, NNNI, p. 75, Jan., 1897. 

Type locality. — Massett, Graham Island, Queen Charlotte Islands. 
British Columbia. 

Geographic distribution. — Moresby and Graham islands, Queen 
Charlotte Group, British Columbia. 

Characters. — Similar to oreas, but ears decidedly smaller; tail 
averaging shorter; skull slightly heavier. Similar to hylaeus, but 
skull heavier, with shorter broader nasals. Size smaller than in 
macrorhinus, prevostensis, and sitkensis. 

Color. — Not appreciably different from that of other forms of the 
northwest coast — oreas, macrorhinus, hylaeus, etc. Worn pelage: 
Sides russet shading into darker Mars brown in middle of back. 
Unworn pelage probably much darker, with dorsum more contrasted 
with sides. 

Skull. — Similar to that of oreas, but averaging slightly heavier, 
particularly in the rostral region. Similar to that of hylaeus, but 
nasals and rostrum shorter and thicker; posterior nasal endings 
usually about equaling premaxillse; skull slightly heavier throughout. 

Measurements. — Average of 20 males from Skidegate, Graham 
Island: Total length 197 (186-212) ; tail vertebrae 102 (95-111) ; hind 
foot 22.7 (22-23); ear from notch (dry) 14.7 (14-15.2). Of 15 
females from the same locality: 199.8 (181-209) ; 103.4; 22.4 (22-23). 

Type x/>< cimen. — Xo. 7768 Collection Academy of Natural Sciences, 
Philadelphia ; formerly No. 768 Collection of S. N. Rhoads. $ young 
adult. 1892. J. H. Keen. Specimen in alcohol, except skull, which 
has been removed and preserved separately. It is of little value for 

Remarks. — This mouse is of the same general type as P. m. oreas 
of the Puget Sound region and P. in. hylaeus of the islands and coast 
of southeastern Alaska. It is most closely related to hylaeus, being 
distinguished only by slight cranial characters. Since these charac- 
ters, although reasonably constant, vary slightly towards hylaeus, it 
seems fitting to include keeni among the numerous subspecies of 
manic ul at us. The only other white-footed mouse occurring on the 
Queen Charlotte Islands is P. s. prevostensis, which, although nearly 
the same color, is so much larger than keeni as not to require close 

Specimens examined. — Total number 108, from localities in the 

Queen Charlotte Islands as follows: 

Graham Island: Massett, 10; Skidegate Inlet, 50. 
Moresby Island: Curushewa Inlet, 40; near Rose Harbor, 8. 



Tii tie from head of Lake Bennetl (site of old Bennetl <'ity). British Columbia. 
No. 130013 I T . S. National Museum, Biological Survey Collection. $ adult. 
Sept. 17, 1903. \Y. II. Osgood. 

Geographic distribution. — Region of the headwaters of the Yukon 
River from Lake Bennett to the Lower pari of the Lewes River. 

Characters. — Similar to hylat us, but color paler and more grayish ; 
similar to oreas, hut paler and with shorter tail and ears. 

Color. — Much as in arcticus, but with rather less dusky; similar to 
hylaeus but decidedly paler and more grayish. Unworn pelage: 
Upperparts between cinnamon and isahella color, mixed with dusky 
rather lightly on sides and more heavily in middle of back, over quite 
an area of which it predominates; head and face and sometimes 
shoulders slightly grayish ; orbital ring and dusky spot at base of 
whiskers present, hut less conspicuous than in hylaeus. Worn pelage : 
Sides cinnamon or wood brown to russet, becoming slightly darker on 
dorsum; dusky mixture seldom or never thoroughly eliminated; ears 
rather broadly edged with whitish; pre-auricular lanuginous tufts 
usually with a few T white hairs. 

Skull. — Very similar to those of oreas and hylaeus; possibly aver- 
aging slightly larger; larger than in arcticus, with larger teeth and 
zygomata more compressed anteriorly. 

Measurements. — Average of 20 adult topotypes: Total length 192 
(178-204) ; tail vertebra? 94 (83-101) ; hind foot 22.5 (22-23.5) ; 
ear from notch (dry) 15.8 (15-16.4). 

Remarks. — This is a slight form, the interior representative of the 
dark coast form hylaeus. It is very similar to oreas, differing onty 
in slightly paler color and in shorter tail and ears. Possibly the two 
intergrade in the interior of northern and central British Columbia. 
Although arcticus and oreas appear to intergrade in southern British 
Columbia, arcticus and algidus occur together in the range of algidus 
and maintain their distinctness. Although nearly the same color. 
they are easily distinguishable by size and cranial characters. In the 
flesh, their distinctness is even more apparent. This form as well as 
oreas bears some general resemblance to gracilis, the long-tailed form 
of the East. All the similar western forms, however, regardless of 
color or length of tail, differ from gracilis in larger hind feet and in 
larger skulls with heavier teeth. 

Specimens examined. — Total number 00, from localities as follows: 

Alaska: Glacier. White Pass Railroad, 11; Haines, 1 (approaching 

hylaeus) : Skagway, 1 ; Summit, White Pass, 1. 
British Columbia: Bennett, 41; Cheonnee Mountains, 1. 
Yukon Territory: Caribou, 2; Fifty Mile River, 1; Lake Tagish, 4; 

White Horse, 3. 

a Algidus = very cold, pertaining to a cold climate. 

1909.] MANICTJLATUS ( IKOI'P— M A< IK )|{ 1 1 1 X rs. 57 


Sitomys maerorhinus Rhoads, Proc. Acad. Nat. Sci. Phila., pp. 259-260, Oct. 23, 

IS! 14. 
P[eromyscus] maerorhinus Baugs, Am. Naturalist, XXXI. p. 75, Jan., 1S97. 

Type locality. — North Pacific Salmon Cannery," mouth of Skeena 
River, British Columbia. 

Geographic distribution. — Mainland coast of northern British 
Columbia and southern Alaska. 

Characters. — Size very large (hind foot 24-25) ; color dark and 
rich. Similar to oreas, but decidedly larger; tail relatively shorter. 
Similar to hylaeus, but larger throughout. Similar to sitkensis, but 
smaller, skull decidedly smaller and more slender. 

Color. — Almost as in areas, possibly averaging slightly darker. 
Worn pelage: '' Sides varying from rich russet to Mars brown; mid- 
dle of back slightly darker, approaching Prout brown and burnt 
umber; orbital ring and spot at base of whiskers rather extensive 
and contrasted (probably more so in unworn pelage); 'ankles' 
broadly dusky brownish behind, foreleg "with a russet stripe extend- 
ing from side nearly or quite to wrist ; underparts creamy white." 

Skull. — Similar to that of areas and hylaeus, but decidedly larger; 
nasals more elongate; molariform teeth larger; zygomata more com- 
pressed anteriorly. Similar to that of sitkensis, but smaller; rostrum 
more slender; molariform teeth smaller; audital bullae relatively 

Measurements. — Average of 6 adults from Inverness, mouth of 
Skeena River, British Columbia: Total length 209 (200-217); tail 
vertebrae 112 (105-117) ; hind foot 24.5 (24-25) ; ear from notch 
(dry) 16.1 (15-17). Average of 10 adults from Wrangell, Alaska: 
215 (202-222) ; 112 (104-123) ; 23.8 (23-24.5). 

Type specimen. — No. 8381 Collection Academy of Natural Sciences, 
Philadelphia. Formerly No. 1381 Collection of S. N. Rhoads. Col- 
lected by J. H. Keen. Skin in alcohol. Skull not thoroughly 
cleaned; right zygoma and part of infraorbital plate broken away; 
otherwise in good condition. 

Remarks. — The mice of the northwest coast, including areas, 
maerorhinus, hylaeus, sitkensis, and keeni, are very similar in color, 

°The exact locality, as I am informed by Itev. J. H. Keen, who collected the 

6 Specimens in complete unworn pelage are not at hand. As indicated by a 
few specimens in changing pelage, it would be very nearly the same as in oreas 
and hylaeus. 

'One specimen from Inverness. British Columbia, is abnormally colored. 
The entire underparts are rich brownish russet like the sides; the underside 
of the tail is flecked with dusky; and the feet arc brownish dusky to the bases 
of the toes. Thus the only white on the animal is on its toes. 


and the various forms are distinguishable only by size, proportions, 
and slight cranial characters. With the exception of sitkensis and 
prevostensis, macrorhinus is the largest of these northwest coast 
forms. Since sitkensis and prevostensis are insular in distribution 
so far as known, macrorhinus is the only very large mainland form. 
Its size readily distinguishes it from oreas and hylaeus, though in- 
dications of intergradation with each are known, and specimens from 
outlying localities therefore may prove troublesome. A series from 
River Inlet, British Columbia, seems to show intergradation between 
macrorhinus and oreas, containing, as it does, individuals which may 
be referred without violence to either one, and others that are as 
nearly halfway between the two as conceivable. Another series from 
Petersburg, Alaska, though referable to hylaeus, have somewhat 
larger teeth than that form and may be considered as connecting 
hylaeus with macrorhinus. Thus it appears that the type locality 
of macrorhinus is in about the center of its range, a most unusual 
circumstance, for when it was described absolutely nothing was 
known of the distribution and relationships of the mice of the north- 
west coast and the type locality was determined only by the location 
of the first collector to secure specimens and forward them to a 

Specimens examined. — Total number 111, from localities as 
follows : 

Alaska: Loring, Revillagigedo Island, 34; Woronkofski Island, 6; Wran- 
gell, 33. 

British Columbia: Metlakatla, 4;" Port Simpson, 3; River Inlet, 22 
(approaching oreas); mouth of Skeena River, 9 (Inverness, 8; 
North Pacific, 1). 


Sitomys americanvs artemisiae Rhoads, Proc. Acad. Nat. Sci. Philadelphia, 

pp. 260-261, Oct. 23, 1894. 
Peromyscus texcmus subarcticus Allen, Bull. Am. Mus. Nat. Hist., N. Y., XII, 

pp. 15-16, Mar. 4, 1899— Deerlodge County, Mont. & 
Peromyscus texanus artemisiae Miller and Rehn, Proc. Bost. Soc. Nat. Hist., 

XXX, p. 84, Dec, 1901. 

Type locality. — Ashcroft, British Columbia. 

Geographic distribution. — South central British Columbia, north- 
eastern Washington, northern Idaho, western Montana, and western 
Wyoming. Transition and Canadian zones. 

Characters. — More or less similar to arcticus, raftnus, and gambeli; 
size about as in arcticus, color somewhat paler, skull narrower; color 

a Collection of Canadian Geological Survey. 

6 The exact locality is " SW. corner of Deerlodge Co. — about 20 miles west 
and a very little north of Anaconda — near a Post Office called Cable," as I am 
informed by a letter from the collector, Prof. L. L. Dyche. 


about as in gambeli, though slightly darker, size larger; color less 
tawny and size larger than in rufinus; white in subauricular tufts 
nearly obsolete; tail shorter and color paler than in oreas; darker and 
larger than nebrascensis and sonoriensis. 

Color. — Ground color of upperparts varying from pale cinnamon 
to brownish fawn, about as in gambeli, duller and less tawny than 
in rufinus; dusky mixture usually somewhat concentrated on dorsum 
into an irregular darker area; ears dusky, whitish edged; sub- 
auricular tufts, when conspicuous, chiefly huffy cinnamon, lightly 
mixed with dusky, white much reduced or absent; a dusky spot at 
base of whiskers; eyelids and sometimes a very narrow orbital ring 
dusky; feet white; forelegs white or often with a light mixture of 
dusky to wrists; ' ankles ' dusky; underparts creamy white; tail dark 
brownish above, white below. Worn pelage : General color rather 
dull; sides pale fawn to russet; dorsum russet to Prout brown. 
Adolescent pelage: Ground color pale drabby fawn heavily mixed 
with dusky, slightly increased on dorsum ; general effect of upper- 
parts broccoli brown to hair brown. Young in first coat: Base of 
hairs slate color to blackish slate ; general effect of upperparts mouse 
gray, decidedly darker and more slaty on dorsum. 

Skull. — Much as in rufinus and gambeli, but averaging larger and 
more elongate w 7 ith longer nasals; similar to that of areticus, but 
averaging narrower with less spreading zygomata and longer more 
slender nasals. 

Measurements. — Average of 6 topotypes: Total length 167 (155- 
180) ; tail vertebrae 75 (69-86) ; hind foot 20.5 (19-22) ; ear from 
notch (dry) 16.1 (15-17). Of 5 adults from Similkameen River: 
172 (158-186); 77.5 (68-82): 20.2 (20-21). 

Type specimen. — No. 7368 Collection of Academy of Natural Sci- 
ences, Philadelphia. Formerly No. 368 Collection of S. N. Rhoads. 
$ adult. July 5, 1892. S. N. Rhoads. A flat skin without stuff- 
ing, but otherwise in good condition ; tail stiffened with a quill ; skull 
practically perfect. 

Remarks. — -It is extremely difficult to characterize this form since 
it shows some resemblance to so many surrounding forms. It 
seems to be an aggregation of intermediates, but sufficiently con- 
stant and restricted in range to merit recognition. Its recognition 
as a distinct form is far more satisfactory than an attempt to adjust 
it with the several related forms, with none of which it thoroughly 
agrees. In a way, it connects the long-tailed and the short-tailed 
forms of the maniculatus group, although intergradation between 
the two series occurs also elsewhere. The gradation from gambeli 
via artemisiae to oreas seems to be complete, although at certain 
localities representatives of each may be found apparently preserv- 
ing distinctness. At St. Mary Lake, Montana, two forms occur, one 


referable to nebrascensis and occupying the open sagebrush country, 
and the other, called artemisiae, being confined to the heavy forest. 
Although distinct here and apparently free from hybridization, each 
form is connected by slight gradations with the same parent ( ?) 
form. The majority of the series called artemisiae are indistinguish- 
able from topotypes except by size, and in this respect variation in 
the series extends from the average dimensions of artemisiae to those 
of oreas. The closest relations of artemisiae are with arcticus, and 
some specimens are almost indistinguishable. Additional material 
from central and northern British Columbia, western Montana, 
northern Idaho, and adjacent regions, supplemented by careful field 
studies, would doubtless reveal some very interesting facts regarding 
intergradation and distribution, and it may be necessary later for 
artemisiae and arcticus to be thrown together; for the present both 
may be recognized. P. m. artemisiae intergrades even with sonorien- 
sis, as proved by specimens from east-central Idaho, and these in turn 
merge with nebrascensis, rufinus, gambeli, etc., and so connection 
with all the forms of this remarkable group is shown. P. subarcticus 
Allen is an absolute synonym of artemisiae, the type being indis- 
tinguishable in even the slightest degree from topotypes of artemisiae. 
Specimens examined. — Total number 549, from localities as fol- 
lows : 

British Columbia: Ashcroft, 28; Barkerville, 1 ; Bonaparte, 1; Ducks, 2; 
Field, 16 (approaching oreas and arcticus) ; Glacier, (approach- 
ing areas and arcticus) ; Gold Range, 1 ; Golden, 8 (approaching oreas 
and arcticus); Hope and near Hope, 87; 125 Mile House, Caribou 
Road, 2; Kamloops, 15 ; a Lac La Hache, 2; 6 Midland, 1 ; a Moniskee 
Divide, 15; Myer Creek, 2 ;« Nelson. 18; Okanagan, .14 ;° Okanagan 
Lake, 3; Rossland, 1;" Shuswap, 3; Sieamous, 13 (approaching 
oreas); Similkameen River, 5 miles north of U. S. boundary, 7; 
Sophia Mountains, 1 ; a Spenees Bridge, 2;" Vernon, 6. 

Idaho: Litter Root Mountains, 1 ; Coeur d'Alene, 19; near Collins. Latah 
County, 2; Craig Mountains, 1 ; Fiddle Creek, 4; Freedom, 1 ; Kings- 
ton, 2; Mission, 1; Mullan, 8; Osborn, 3; Priest Lake, 8 (approach- 
ing oreas) ; Seven Devils Mountains, 3. 

Montana: Beartooth Lake,G; Beartooth Mountains,2; Deerlodge County, 
::-, Flathead Lake. 13; Helena, 2; Horse Plains, 3; Hot Springs 
Creek, 1; Kalispell, 1; Little Bitter Root Creek, 3; Lolo, 5; Nyack, 
7; Prospect Creek, 5; St. Mary Lake, 10 (approaching oreas); 
Saltese, 10; Stanton Lake, 1; Stepbensville, 4; Summit, 2; Thomp- 
son Falls, 1; Thompson Pass, 4; Tobacco Plains, 11 ; Upper Stillwater 
Lake. 1. 

Oregon: Elgin, 3 (approaching gambeli) ; Wallowa Lake, 14 (approach- 
ing gambcli) ; Wallowa Mountains, 1. 

Washington: Asotin, 2 (approaching gambeli) ; Blue Creek, 5; Cheney, 
2; Columbia River (Lord), 1; Colville. 15; Conconully, 3; Crab 
Creek, Lincoln County, 1 (approaching gambeli); Davenport, 1; 

a Collection Canadian Geological Survey. 
6 Specimens poor, position doubtful. 


Douglas, 1; Easton, 2; Fort Spokane, 2; Marcus, 4: Rock Lake, 2; 
Spokane Bridge, 15; Spokane Falls, 1; Wawawai, 2 (approaching 
gambeli i. 
Wyoming-:" Baggs Crossing (30 mi. NWY), 8; ("larks Fork, !.* ; Jack- 
sons Hole, 1; La Barge Creek, 3; Lake City, 10; Mammoth Hot 
Springs, 34; Yellowstone Park, 4. 


Peromyscus texanus saturatus Bangs. Am. Naturalist, XXXI, pp. 74-7.~>, Jan. 1, 

Type locality. — Saturna Island, Island District, British Columbia. 

Geographic distribution. — Confined to Saturna Island. 

Characters. — Similar in color to P. in. axsterus, but lateral line and 
cinnamon beneath base of tail more conspicuous; size larger; skull 
larger, broader, and more angular; hind foot '21 to 22; tail shorter 
than head and body. 

Color. — Unworn or slightly worn pelage: Upperparts very dark; 
general effect cinnamon heavily clouded with blackish, the latter 
somewhat concentrated dorsally; lateral line cinnamon, rather well 
defined, extending to the heels, which are mixed cinnamon and dusky, 
and broadening across the interfemoral region beneath the tail into 
a conspicuous patch of nearly clear cinnamon ; upper side of arm to 
wrist cinnamon lightly mixed with dusky; ears dusky brownish, 
edged with whitish, subauricular tufts same color as rest of upper- 
parts; tail blackish brown above, white below; underparts creamy 
white not thoroughly concealing slaty undercolor. Worn pelage : 
Sides bright cinnamon to russet, blending with the lateral line which 
is much less contrasted than in unworn pelage; back dark, Mars 
brown to mummy brown and Prout brown. Adolescent pelage: 
Sides drabby hair brown or sooty isabella color; narrow cinnamon 
lateral line usually well marked; back with a rather well-defined 
sooty grayish brown stripe. 

Skull. — About the size of that of oreas but more angular and more 
arched in the interorbital region; larger, broader, and more angular 
than in an sterns; audital bullae and molar teeth about as in oreas, 
slightly larger than in austerus. 

Measurements. — Average of 10 adults from the type locality (fide 
Bangs, 1. c.) : Total length 180.9; tail vertebrae 76.2; hind foot (dry) 

Type specimen. — No. 2581 Museum of Comparative Zoology, Cam- 
bridge, Mass., formerly same number Collection of E. A. and O. 
Bangs. $ adult, January 31, 1804. W. C. Colt. Specimen in 
fair condition. Skull with nasals slightly broken anteriorly; other- 
wise perfect. 

a All approaching rufitms, 


Remarks. — Although typical austerus occurs on both sides of Puget 
Sound and even on Vancouver Island, it does not appear to range 
unchanged over the small islands between Vancouver Island and the 
mainland. The form of Saturna Island will perhaps be found on 
adjacent islands and may be connected by them with austerus. Cer- 
tain aberrant specimens from the mainland at Howe Sound and 
Malaspina Inlet, British Columbia, show some approach to saturatus, 
particularly in their skulls, but for the present seem best considered 
as variously intermediate between the mainland forms. 

Specimens examined. — Total number 221, all from the type 


(PI. II, fig. 6.) 

Type from Friday Harbor, San Juan Island, San Juan County, Wash. No. 
130316 IT. S. National Museum, Biological Survey Collection. $ adult, Oct. 
23, 1903. N. Hollister. 

Characters. — Color almost as in saturatus/ skull larger and heavier, 
with larger molar teeth, and larger audital bulla?. 

Color. — Almost as in saturatus; ground color a slightly paler shade 
of cinnamon ; lateral line not so sharply defined. 

/Skull. — Similar to that of saturatus, but larger and heavier; palate 
broader, molar teeth heavier; audital bullae actually and relatively 

Measurements. — Average of 10 adult topotypes : Total length 180.8 
(167-188) ; tail vertebrae 79.3 (73-84) ; hind foot 22.1 (21-22.5) ; ear 
from notch (dry) 16.8 (15.2-17.2). 

Remarks. — The relationship of this form to saturatus is evident. 
The cranial characters by which it differs are constant, and it seems 
necessary to recognize them, especially since it is an insular form. 
The evident deviation of both saturatus and hollisteri from mainland 
forms of the maniculatus series seems best expressed by trinomial 
names, particularly since so many of the small islands of the Puget 
Sound region are as yet unrepresented by specimens in collections. 
The whole question of the interrelations of orcas, austerus, and 
artemisiae is not as yet satisfactorily worked out, and much material 
and careful field notes from islands and mainland coasts of southern 
British Columbia and northern Washington are greatly to be desired. 

Specimens examined. — Total number -11, all from the type locality. 



(PI. II, tig. 3.) 

Eesperomys wsterus Baird, Proc. Acad. Nat. Sci. Phila., VII, p. 336, 1855. 
P[eromyscus] austerus Bangs, Am. Naturalist, XXXI. p. 75, Jan., 1897: 
Peromyscus akeleyi Elliot, Field Col. Mus., Chicago, Zool. Ser. I, p. 22(3, Feb., 
1899 — Elwah River, Olympic Mountains, Washington. 

Type locality. — Old Fort Steilacoom, Wash. 

Geographic distribution. — Coast region of Puget Sound, Washing- 
ton ; north to southern British Columbia and including Vancouver 

Characters. — Size medium (hind foot 19-22, tail usually less than 
100) ; color very dark. Similar to oreas, but decidedly smaller and 
more sooty in color; similar to saturatus and rubidus, but skull 
smaller and narrower; similar to gambeli, but very much darker 
and with different skull. 

Color. — Unworn pelage: Ground color of upperparts brownish 
fawn ; sides with liberal mixture of sooty, middle of back with still 
more, forming a more or less distinct sooty stripe; ears sooty, very 
narrowly edged with whitish, no white at anterior bases; a narrow 
dusky orbital ring and a small dusky spot at base of whiskers ; under- 
pays creamy white, slaty undercolor usually showing through; tail 
sooty above, white below ; ' ankles ' dusky brownish. Worn pelage : 
Sides Mars brown to Prout brown ; dorsum Prout brown to mummy 
brown. Adolescent pelage : Sides grayish wood brown heavily mixed 
with sooty, middle of back and top of head black or nearly black, 
shoulders slightly less intense. 

Skull. — Size small; braincase very narrow; nasals rather short; 
zygomata not 'squared' anteriorly; molariform teeth small; palatine 
slits short. Most similar to that of gambeli, but narrower and more 
elongate; zygomata lighter; decidedly smaller than in saturatus, 
oreas, and rubidus. 

Measurements. — Average of 10 topotypes: Total length 172 (163- 
190) ; tail vertebras 86 (79-96) ; hind foot 20.5 (20-21) ; ear from 
notch (dry) 15 (14-15.5). Of 10 adults from Goldstream, Vancouver 
Island, British Columbia: 173 (170-178) ; 85 (81-89) ; 20.3 (19-21). 

Type specimen. — In the original description of austerus, Baird 
does not designate a type but mentions two localities, thus : " Col- 
lected at Fort Steilacoom, Puget Sound, by Dr. Geo. Suckley, 
U. S. A., and by Dr. Cooper on the Spokan Plains." In 1857, two 
years later, he published a more complete description and listed 1 
specimen from Spokane Plain and 11 from Steilacoom, 4 of the latter 
queried and mentioned in the text as possibly belonging to another 
form (Mamm. N. Am., p. 466, 1857). Allen (Bull. Am. Mus. Nat. 
Hist., V, id. 192, 1893) has selected Steilacoom as the type locality 
of austerus on the grounds that it is the locality first mentioned in 
the original description and the one from which came the majority 


of the specimens examined by Baird in L857. Miller and Rehn (Proc. 
Bost. Soc. Nat. Hist., XXX. p. 69, Dec, 1901), either unaware of 
Allen's action or in exception to it, gave Spokane Plain as the type 
locality. There appear to be good grounds for either decision, but 
Allen's, having priority, is entitled to more consideration even though 
it can not be denied that the specimen from Spokane Plain may have 
been the chief basis of the original description. The statement by 
Baird (Mamm. X. Am., p. 466) that "the Hesperomys austerus has 
thus far only been found in the eastern part of Washington Terri- 
tory" is hard to understand in connection with the list of specimens 
immediately following, the majority of which are from western 
rather than eastern Washington. No. 1004, II. S. Xational Museum, 
from Steilacoom, which is one of the specimens listed in 1857 now- 
extant, was considered the type by Coues, and now bears a type 
label, but as it was not collected until 1856, the year following the 
first publication of the name, and as its measurements do not agree 
with those of the original description, obviously it can not logically 
be considered the type. The measurements given in the original de- 
scription do not agree exactly with those of the specimen from Spo- 
kane Plain as published by Baird in 1857, nor yet with an} r of those 
from Steilacoom, so no conclusion can be adduced from that source. 
On the whole, the question appears to be open, and therefore Allen's 
right to fix Steilacoom as the type locality can not fairly be disputed. 

Of Baird's original specimens from Steilacoom now extant, Xo. 
364 U. S. National Museum (skull only) may perhaps be regarded 
as the type. It is badly broken and of little value for comparison 
(see Lyon and Osgood, Bull. U. S. Nat. Mus. Xo. 62, p. lV>. 1909). 

Remarks. — Typical austerus appears to be confined to the imme- 
diate vicinity of Puget Sound. Specimens from Howe Sound and 
Malaspina Inlet on the coast of southern British Columbia are 
slightly large, but do not seem separable. In cranial characters some 
of them approach oreas very closely, but others are exactly like aus- 
terus; since the majority have skulls more similar to austerus and 
all have rather short tails and hind feet, they are referred to austerus. 
In the same way, specimens from Lake Cushman and the Skokomish 
River in the eastern Olympic Mountains are larger than typical; 
these, however, may possibly be tending toward rubidus. The series 
representing l P. akeleyV also comes within this category. The type, 
however, is like austerus in size and cranial characters. Specimens 
from Vancouver Island are almost exactly like topotypes, differing 
only in having slightly wider braincases. Some specimens from the 
coast of Oregon approach austerus quite decidedly, but the general 
average of the majority from that region seem referable to ruMdus, 
chiefly on account of their larger, broader skulls. The occurrence 
of austerus and oreas at the same localities has been discussed in the 
account of oreas. 


Specimens i xamined. — Total number 408, from localities as follows: 
British Columbia: Agassiz, 10; Comox, 6; Chilliwaek Valley 11; (Jib- 
son Landing, Howe Sound, 12 ; a Goldstream, 27; Hasting? 3; Kent, 
2; Langley, 1; Lund, Malaspina Inlet, 20;° Mount Baker Range, 1; 
.Mount Lehman, 1; Port Moody, 14; Salt Spring Island, 2;° Sunias, 
22; Victoria, 26 ; 6 Wellington, 3; Westminster, 9. 
Washington: Aberdeen, 9; a Avon, 5; Boulder Creek, 30 ; c Bou er Lake, 
1; Elwah River, Olympic Mountains, 38 ; c Lake Cushrnan, 1; Hamil- 
ton, 3 ; Happy Lake, 2 ; Johnson Ranch, Elwah River, 2 ; Mount Elli- 
nor (3 m. SE.), 2; Mount Vernon, 28; Nesqually Flats, 31; Roy, 1 : 
Sauk, 2 ; Seattle, 9 ; North Fork Skokomish River, 21 ; Soleduck 
River, 1 ; ° Steilacooin, 40 ; Tacoma, 3 ; Tenino, 3 • Whidby Island, 6. 


Pcromyscus oreas rubidus Osgood, Proc. Biol. Soc. Wash., XIV, pp. 193-194, 

Dec. 12, 1901. 
Peromyscus perimekurus Elliot, Field Col. Mus., Chicago, Pub. 74, Zool. Ser., 

Ill, p. 156, Apr., 1903— Goldbeach, Oreg. 

Type locality. — Mendocino City, Calif. 

Geographic distribution. — Coast of California and Oregon from 
San Francisco Bay to the mouth of the Columbia River. 

Characters. — Similar to oreas, but tail and hind foot shorter; simi- 
lar to austerus, but color paler, skull larger and broader; similar to 
gambeli, but tail longer and color darker. 

Color. — Unworn pelage: Ground color of upperparts cinnamon; 
black mixture rather heavy on sides, predominating on back, form- 
ing a broad blackish stripe from shoulders to base of tail or an 
irregular patch between shoulders and rump : head and shoulders- 
somewhat grayish ; a conspicuous blackish orbital ring and spot at 
base of whiskers; ears dusky, edged with whitish; very few or not 
any white hairs at anterior bases of ears ; feet white, ' ankles 1 dusky : 
tail blackish above, white below; underparts creamy white. Worn 
pelage: Sides faw T n color to russet; dorsum russet to Mars brown; 
face and head nearly like sides; dusky mixture often almost entirely 
eliminated or so faded as to show scarcely any contrast with ground 
color. Adolescent pelage: General effect of upperparts varying 
from grayish hair brown to hair brown tinged with fawn. Young 
in first coat : General color mouse gray, more or less sooty in middle 
of back. 

Skull. — Similar to that of gambeli, but larger and heavier; similar 
to that of oreas, but with nasals averaging slightly shorter; somewhat 
similar to that of austerus, but decidedly larger and heavier, brain- 
case broader, teeth heavier. 

Measurements. — Three adult topotypes: Total length, 189. 100. 
203; tail vertebra', !><>. !>:>. W: hind foot. 21. 22. 21. Average of 6 

"Approaching oreas? 

6 Collection of Canadian Geological Survey. 
r May include some specimens of P. hi. oreas. 
66268— No. 28—09 5 


adults from Mendocino County, Calif., 193 (189-203), 96 (90-100), 
21.5 (21-22), ear from notch (dry), 15.8 (15.2-16.9). 

Type specimen. — No. 91650 U. S. National Museum, Biological 
Survey Collection. <j> adult. November 17, 1897. J. Alden Loring. 
Specimen in good condition. 

Remarks. — The range of this form follows quite closely the humid 
coast belt of California and Oregon. Specimens from the southern 
part of its range approach gambeli, and in the north, near the mouth 
of the Columbia River, approach to oreas or austerus or both is 
evident. Some series from this latter region are too variable to admit 
of satisfactory classification, for they contain individuals showing 
some of the characters of any of the three closely related forms, 
oreas, austerus, and rubidus. The difficulty is increased b}^ two 
names, dkeleyi and perimekurus, which confront the reviser. Their 
respective types do not exactly agree with any of the other forms, 
and series from their type localities contain large and small, dark and 
light individuals. Neither form can be definitely characterized, and 
the soundest procedure seems to be to consign each to the form which 
appears to be dominant in the region from which it comes. Thus 
dkeleyi falls under austerus and perimekurus under rubidus. Spec- 
imens from the Willamette Valley are nearly typical, though possibly 
tending in slight degree toward gambeli. All along the border 
between the humid coast and the relatively arid interior are found 
intermediates between rubidus and gambeli, or in some localities 
the two forms are found side by side. Six specimens from the Outer 
Peninsula, near Samoa, Humboldt Bay, are decidedly paler than 
others from the neighboring redwoods. They evidently represent 
an incipient and very local subspecies, and well illustrate the plasticity 
of the group to which they belong. A careful study of this variation 
and the local conditions doubtless would prove instructive. An aber- 
rant specimen is present also in the series from Wells, Oreg. It is so 
much paler than the others of the series that partial albinism is sug- 
gested, but possibly local environment may be the true explanation. 
Specimens examined. — Total number 838, from localities as follows : 
California: Alton, 11; Alton Junction, 8; Berger Creek, 4; Blue Lakes, 
1; Bodega, 10; Briceland, 4; Canto, 17; near Calpella, 2; Camp 
Meeker, 1 ; Canyon Creek, Trinity County, 1 ; Cape Mendocino, 2 ; 
Cazadero, 1 ; Crescent City, 51 ; Dyerville, 7 : Eureka, 15 ; Freestone, 
2; Gasquet, 8; Hoopa Valley, IS; Humboldt Bay, 19 (Carson Camp, 
Mad River, 13; Outer Peninsula, near Samoa. 6°); Inverness, 8; 
La Honda, 46 ; Laytonville, 1 ; near Lower Lake, 18 ; Mad River, 2 ; 
Marshall, Marin County, 5: a Mendocino City, 15; Mount Tamalpais, 
1; Nicasio, 67; Novato, 2; Olema, 6; a Orick, 21; Petrolia, 10; Point 
Reyes, 38;° Portola, 160;° Requa, 18; Rio Dell, 1; Rockport, 2; 
Sherwoods, 15; Siskiyou Mountains (Shelley Creek), 3; Smith 
River, 4; Sur, 10 ; a Ukiah. 11 ;" Westport, 1 ; Woodside, 2." 



Oregon: Agnes, 2; Astoria, 12; Beaverton, 1; Elkhead, 1; Florence, 7; 
Forest Grove, 1; Gardiner, 22; Glendale, 1; Gold Beach, 17; Grants 
Pass, 5;° Marshfleld, 3; McCoy, '.»; Mount Hood (west slope), 1; 
Oregon City, 5 ; Portland, 22 ; Port Orford, 2 ; Prospect, 12 ;« Riddle, 
1; Rogue River Valley, 2; a Roseburg, 5;° Scottsburg, 6: Seaside. 15; 
Sheridan, 6; Tillamook, 1; Wells, 20; Yaquina, 6; Yaquina Bay, 4. 


(PL II, fig. 12.) 

Hesperomys gambelii Baird, Mamm. X. Am., Pac. R. R. Reports, VIII, pp. 464- 

465, 1857. 
Sitomys americanus gambelii Allen, Bull. Am. Mus. Nat. Hist., X. Y., V, pp. 

190-191, Aug. 18, 1893. 
Sitomys americanus thwrberi Allen, supra eit., pp. 185-186 — San Pedro Martir 

Mountains, Lower California. 
P [eromyscus] t[eoeanus] gambelii Mearns, Proc. 1". S. Nat. Mus., XVIII, p. 446, 

Mar. 25, 1S96. 
Peromyscus texanus melius Mearns, Proc. U. S. Nat. Mus., XVIII, p. 446, 

Mar. 25, 1896 — Nachoguero Valley, Lower California. 

Type locality. — Monterey, Calif. 

Geographic distribution. — Central Washington east of the Cas- 
cades, thence south through central and eastern Oregon to California ; 
throughout California except the ' redwood strip ' of the northwest 
coast and except the southeastern desert region and the region east of 
the Sierra ; south into northwestern Lower California. Upper So- 
noran to Hudsonian zone. 

Characters. — General characters similar to rufinus, sonoriensis, 
and artemisiae; color much as in rufinus, but usually duller, less 
tawny ; decidedly darker, more clouded with dusky than in sonorien- 
sis; size smaller than in artemisiae; also slightly smaller than sonor- 
iensis; somewhat dimorphic in color, but with one phase greatly pre- 
dominating; somewhat similar to rubidus. but smaller, with shorter 
tail and less intense color. 

Color. — Buff phase h in unworn pelage: Upperparts between ochra- 
ceous and ochraceous buff heavily and nearly uniformly mixed with 
dusky, producing a general effect varying from rusty isabella color 
to bister ; sides nearly or quite like back ; underparts creamy white ; 
ears dusky, narrowly edged with whitish; subauricular tufts same 
color as back, white spots nearly or quite obsolete; no definite dusky 
facial markings; feet white, w ankles' slightly dusky or nearly white; 
tail bicolor, dusky brownish above, white below\ Dark phase : Rather 
variable, but in general more dusky and more vinaceous than buff 

a Approaching gambeli. 

^ The predominating phase, and though not so distinctly buffy as the buff 
phases of sonoriensis and blandus, it is evidently the corresponding condition. 


phase; genera] effecl Mars brown strongly tinged with fawn. Worn 
pelage: General effect of upperparts varying from clay color or dingy 
ochracebus buff to lightly grizzled fawn color, dusky mixture changed 
to cinnamon or brownish, but seldom so thoroughly eliminated as in 
sonoriensis; sides usually nearly the same as back. Adolescent 
pelage: General effecl of upperparts varying from hair brown to 
sepia, dusky mixture often very strong. Young in first coat: Bases 
of hairs slate color or blackish slate, tips mouse gray, usually slightly 
darker on back than on sides; general effect grayish slate color. 

Skull. — Practically as in sonoriensis but averaging slightly smaller; 
smaller and with shorter nasals than in artemisiae; decidedly smaller 
than in rubidus, with smaller teeth, smaller and narrower braincase, 
and shorter, relatively broader, nasals. 

Measurements. — Average of 6 adult topotypes: Total length 159 
(148-170) ; tail vertebra? 71.6 (64-80) ; hind foot 20; ear from notch 
(dry) 14.9 (14.2-15.8). Of 10 adults from Stanford University, 
California: 161 (157-173); 7±4 (70-77); 20. Of 10 adults from 
northwestern Lower California: 170 (100-183); 80 (69-86); 20.7 

Type specimen. — An individual type was not specified by Baird. 
His list of specimens with the original description includes various 
localities in Washington, Oregon, and California. Since the list 
appears to follow a geographic sequence from north to south, the 
specimens from Washington are mentioned first. It is evident, how- 
ever, that the specimens from California formed the principal basis 
of the description. One from Monterey, Calif. (Xo. 369), is specific- 
ally mentioned in the description, and farther on the form is referred 
to as " the common California species.'' Doctor Allen, therefore, 
in 1893 (1. c. ), designated this specimen (Xo. 369 U. S. National 
Museum) as the type of gambeli. It is not now extant, but a so- 
called cotype, Xo. 368, is in the National Museum. It is in very bad 
condition, having been exposed as a mounted specimen until the color 
has faded very much. The present color is chiefly pale yellowish buff. 
The ears are entirely gone and patches of hair are gone from the 
sides. The skull has been removed from the skin and is in good con- 

Remarks. — P. m. gambeli is one of the most widely ranging and 
best known of the maniculatus group. It is extremely abundant 
throughout its range, and large representations of it are present 
in most American collections. It is quite variable and its intergra- 
dation with surrounding forms is complete. Since it stands between 
sonoriensis and the paler shorter-tailed forms of the group on the 
one hand and rubidus and the darker longer-tailed forms on the 
other, it necessarily includes a considerable range of variation. That 
is, intermediates between gambeli and soitorieiLsix must be quite 


different from intermediates between gambeli and rubidus, although 
both are referable to gambeli because nearer to that than to the other 
forms. For example, specimens from Berkeley, Calif., arc darker 
and longer-tailed than typical gambeli and evidently approach 
rubidus; while others from Jacumba, Calif., are paler than (/<///(/>/// 
and approach sonorit nsis. The Berkeley specimens are therefore 
decidedly darker than those from Jacumba, but they are nearer to 
gambeli than to rubidus, and those from Jacumba likewise nearer 
than to sonoriensis. In studying such material, there is constant 
temptation to treat these intergrades as separate forms, but after 
testing every possible alternative one is forced to conclude that no 
logical subdivision of gambeli as here recognized can be made. 
When the problem is viewed as a wholes — in perspective, so to speak — 
gambeli appears to be a tolerably constant entity throughout what 
may be called the center of its range and about the periphery to 
merge with other forms. Thus, specimens from Monterey, the type 
locality, are absolutely identical with those from San Diego and the 
northeast coast of Lower California, and the intervening region 
is inhabited by exactly the same form. These, moreover, are like 
specimens from the greater part of the interior of California, in- 
cluding the west slope of the Sierra. Whenever this constant form 
meets the range of sonoriensis, however, the effect is immediately 
apparent, and throughout a narrow strip between the ranges of the 
two forms intermediates or mixed specimens fairly representative 
of each form are found. Thus intermediates between gambeli and 
sonoriensis are similar, whether from the San Pedro Martir Moun- 
tains of Lower California or from the eastern slopes of the northern 
Sierras or Cascades. As Monterey, the type locality of gambeli, is 
on the coast not far from San Francisco Bay, it might be supposed 
that topotypes would be nearer to the darker form rubidus than to 
the animal of the coast ranges of southern California. This is not 
the case, however, and the reason is easily understood when the 
local conditions are known. At Monterey it is dry and sandy, and 
these conditions continue inland to the Salinas Valley. Although 
specimens from the Santa Cruz Mountains on one side of Monterey 
Bay and from Sur on the other are referred to rubidus, those from 
the vicinity of the town of Monterey are like those from Salinas and 
other interior localities. 

The transition from gambeli to rubidus along the line between 
their ranges is rather sudden, suggesting the possibility of hybrid- 
izing. From several localities specimens fairly typical of both forms 
are known, from others we have both forms and apparent interme- 
diates, and from still others all specimens thus far obtained are 
intermediates not typical of either form. This is exactly what would 
be expected upon the theory of hybridism, but of course it can not 


be considered as conclusive proof. Specimens from the higher parts 
of the Sierra appear to differ in an extremely slight degree from the 
coast range specimens and apparently approach rufirvus. The amount 
of individual variation is so great, however, that there seems to be no 
means of distinguishing the mountain specimens. In fact, even 
gambety from the region of the type locality differs but little from 
rufinus. Specimens slightly darker or lighter than the average may 
be found almost anywhere in the range, as the animal seems to 
respond to local environment very readily. Thus specimens caught 
in thick woods along a comparatively cold stream may be noticeably 
darker than others taken perhaps within half a mile in the chaparral 
of a dry hillside. It is possible that the first generation of progeny 
from the darker specimens if transferred to the dry hillside would 
be lighter than their parents. Such questions, of course, can be de- 
termined only by experimentation, but obviously variations that 
occur fortuitously throughout wide areas can not be distinguished 
by name. In spite of this frequent variability gambeli is not a 
respecter of zones, as appears in many localities, notably on Mount 
Shasta, where it ranges unchanged from the base of the mountain 
to the rocky cliffs above timberline. In northeastern California 
the mice of the semidesert lava beds are more like the dark gambeli 
than the pale sonoriensis. Throughout the desert region sonoriensis 
is the prevailing form, except on the lava beds. Apparently the 
animals inhabiting lava beds differ from those of the wooded Sierra 
in the causes of their acquiring their dark color, but since they are 
indistinguishable they must be referred to gambeli. 

Specimens examined. — Total number 2,077, from localities as fol- 

California: Adin, 2; Ager, 1; Alila, 11 ; a Alta Peak, Kaweah River, 1; 
Alturas, 2 ; Alum Rock Park, 24 ; Aspen Meadow, Tuolumne County, 
7; Auburn, 2; Ballena, 3;° Banta, 6; Bartlett Mountain. 2; Bart- 
lett Springs, 2; Bear Valley, San Benito County, 1; Belmont, 2; 
Berkeley, 43; Beswick, 1<>; Bieber, 1; Bitterwater, 7; Bloods, Cala- 
veras County, 2; Blue Canyon, 3 ; Brentwood, 1 ; Brownell, 13; Bully 
Cboop Mountains, 3; Bunch Grass Spring. 5; Burbank, 1; Burney, 
1; Burney (12 m. E.), 1; Buttonwillow, 4; Calaveras Big Trees. 15; 
Canyon Creek, 17; Carberry Ranch, 6; Carbondale, 2; Carpentaria, 
2; Cassel, 18; Cedarville, 1;° Chinese Camp, 2 ; Colusa, 2; Cuyamaca, 
1; Dana, 15; Donner, 53; Dos Palos, 1; Dulzura, 19; Dyerville, 1; 
Echo, 6; Emerald Bay, Lake Tahoe, 11; Encinitas, 1; Etna, 1; Fair- 
field, 16 (approaching rubidus) ; Fall River, 5; Ferndale, 6; Fort 
Crook, 10; Fremont Peak. Gabilan Range, 4; Freshwater Creek, 1; 
Fresno, 2; Gaviota Pass. 4: Giant Forest. Sequoia National Park, 2; 
Gilroy, 2: Glen Ellen, 13 (approaching rubidus) ; Goose Lake, 6; 
Goosenest Mountain. 2; Greenville, 2; Grizzly Mountains, 4; Hal- 
stead Meadows. 14: Hayden Hill, 1; Hermit Valley, Calaveras 
County. 15: Hoopa Valley, l' : Horubrook, 1; Horse Corral Meadows, 

Approaching sonoriensis. 


1; Horse Creek, Siskiyou County, 10; Hu en erne, 10; Jackson, 0; 
Jacumba, 54 ; a Jamesburg, 11 ; Jamul, 1 ; Jamul Creek, near El Nido, 
8; Jolon, 5; East Fork Kaweah River, 9; King City, 1; Laguna 
Ranch, 1; Laguna Mountains, San Diego County, it; La Panza, 2; 
Lassen Creek, Modoc County, 5; Lassen Teak, 12; Learlys Kanch, 
Mendocino County, 2; near Leesville, 3; Lemoore, 1 ; Little Shasta, 3; 
Long Valley, Lake County, 2; Los Angeles, 17;" Los Banos 17 ; Lower 
Alkali Lake, 1; Lyonsville, 6; Mad River, 1; Madeline Divide, 4; 
Madeline Plain, 12; Mansfield, 3 : Marysville Buttes, 23: McKinney, 
1; Mendota, 3; South Fork Merced River, 3; Merrillville, 2; Millford, 
2; Mission Santa Cruz, 3; Mohawk, 3; Montague, 4; Monterey, 12; 
Montgomery, 1; Morro, 4; near Morro Pock, 3; Mount Dana. 1; 
Mount Diablo, 1; Mount Hamilton, 3; Mount St. Helena. 16; Mount 
Sanhedrin, 13; Mount Sbasta, 102; Mount Tallac, 7; Mountain 
House, Butte County, 2 ; Nelson, 5 ; Xordhoff, 2 ; Oakdale, 1 ; Orosi, 1 ; 
Orris, 1; Pacheco Peak, 2; Pacific Grove, 2; Palo Alto, 2; Petaluma, 
5; Picard, 15; Pine Valley, Monterey County, 13; Pitt River, 6; 
Pleyto, 2; Point Pinos, 7: Porcupine Flat, 1; Porterville, 3; Port 
Harford, 1; Posts, 5; Poway, 1 ; Pozo, 1; Priest Valley, 1; Pyramid 
Peak, 43; Quincy, 11; 20 miles SW. of Quincy, 12; Ripon, 1 ; River- 
side. 5; Robbins Creek, 4: Rose Canyon, San Diego County, 14 ; a 
Round Valley, Mendocino County, 14; Salinas, 1; Salt Springs, 
Fresno River, 5; San Antonio, G; San Diego, 1; San Fernando, 8; 
Cliff House, San Francisco, 8 (approaching rubidus) ; San Gabriel 
Mountains, 1 ; a San Juan, Orange County, 2; bead of San Joaquin 
River, 2; San Luis Obispo, 11; San Luis Rey, 2; San Mateo, 2; San 
Miguel, 4; San Simeon, 7; Santa Barbara, 1: Santa Cruz, 1; Santa' 
Lucia Peak, 12; Santa Maria, 3; Sauta Monica, 6; Santa Paula, 2; 
Santa Ynez Mission, 3 ; Santa Ynez River, 1 ; Santa Ysabel, 9 ; Saticoy 
1 2; Secret Valley, 3; Sierra City, 4; Sierra Valley, 36 ; a Silver Lake, 
136 ; Sisson, 2 ; Slippery Ford, 4 ; Smith Mountain, San Diego County, 
6; Snow Mountain, 38; Soledad, 1; Sonora Tass, 2: Soquel Mill, 1; 
Sorrento, 1 ; Stanford University, 34; .Stanley (S m. W. of Huron), 1; 
Stillwater, 1; Stockton, 1 ; Summit Lake (12 m. NW. of Lemoore), 1 ; 
Tassajara, 11 ; Tehama, 5 ; Temescal, 3 ; Three Rivers, 6 ; Tower 
House, 1; Tracy, 6; Tulare Lake, 2; Tule Lake, 4; Tuledad Canyon, 
4; Tuolumne Meadows, 3; Twin Oaks, 5 ; Upper Lake, 1; Van Deusen 
River, 2; Ventura, 3; Walnut Creek, 12; Wawona, 3; Weber Lake, 2; 
West Riverside, 2: a Willows, 11; Witch Creek, 1 : South Yolla Bolly 
Mountain, 12 ; Yosemite Valley, 8. 

Lower California: Canyon Salado, 1;" Cape Colnett, 1; Carrizo Creek, 
5; El Alamo, 2;° Encinita, 1; Ensenada, 28; Gato Creek, 2: Guada- 
lupe Valley, 1;° Juncolito, 2; La Huerta, 3; a Los Encinas, 1 ;° 
Nachoguero Valley, 5: edge of Pacific Ocean at Boundary Monument 
No. 258, 3; Pifion, 9;° Pozo Luciano, 1 ; a Rancho San Antonio. 1:2:" 
Rancho Santo Tomas, 2; a Rancho Vie'jo, 6;° Rosarito, 6;" San Felipe, 
2;° Saiios Cedros. 6; San Pedro Martir Mountains (Coll. by Thurber 
and Anthony), 61 ; a San Quentin, 40; Santa Eulalia, 14;° Santa Rosa, 
4;° Sau Telmo, 4; San Vicente, 2; San Ysidro Ranch, 16: Tecate 
Valley, 7; Trinidad, 6;" Ysadora, 1." 

Nevada: Deep Hole, 1; Flowing Springs, 1; Smoke Creek, 4: Summit 
Lake, i. 

"Approaching sonoriensis. 


Oregon: Add, Lake County, 1 ; Anna Creek, Mount Mazama, 6; Antelope, 
10; Make Oven, 1 ; Bend, 7; BuCk Creek, L' ; Burns, 5; Camp Creek, '.',: 
Crater Lake, 14; Crooked River, 4; The Dalles, 9; Detroit, 5; 
Diamond Lake, :',: Fort Klamath, 15; Goose Lake Valley, 2; Harney, 
1; ten miles N. of Harney, 10; John Day River, 1; Lake Alvord, 
3;° Lone Rock, 4 ; Lost River, Klamath Basin, 8 ; Matoles River, 2 ; 
Maury Mountains, 10; Mount Hood, 12 (approaching rubidus) ; 
Mount Jefferson, 11; Narrows, 1.'!; Paulina Lake, 2; Pendleton, 5; 
Plush, 4; Prineville, 8; Rock Creek Sink, 3; Shirk, 2; Siskiyou, 6; 
Stein Mountains, 3; Summer Lake, 4; Summit, 1; Swan Lake Val- 
ley, 2; Twelve Mile Creek, 2; Tule Lake, 4; Wapinitia, 7; Warner 
Mountains, 2; Williamson River, 3. 

Washington: Chelan, 19 (approaching artemisiae) ; Head of ' Lake 
Chelan, 8 (approaching artemisiae); Cleveland, 9; Coulee City, 2; 
Douglas, 1; Goldendale, 2; North Yakima, 7; Trout Lake, 2; We- 
natchee, 3. 


Hesperomys leucopus rufinus Merriam, N. Am. Fauna No. 3, pp. 65-66, Sept. 

11, 1890. 
Peromyscus rufinus Allen, Bull. Am. Mus. Nat. Hist., N. Y., VIII, p. 252, Nov. 

25, 1896. 

Type locality. — San Francisco Mountain, Arizona, at 9,000 feet 

Geographic distribution. — Southern Rocky Mountain region, in- 
cluding the elevated part of New Mexico, scattered peaks and ranges 
in Arizona, eastern Utah, and the greater part of western and central 
Colorado. Transition to boreal zones. 

Characters. — Similar to nebrascensis and sonoriensis, but darker, 
more richly colored, shades of ground color richer and more tawny, 
dusky more extensive; similar to arcticus and artemisiae, but smaller 
and less extensively dusky, skull slightly different; most similar to 
gambeli, but color slightly brighter, more rufescent, particularly in 
unworn pelage. 

Color. — Unworn pelage: Upperparts ochraceous or tawny ochra- 
ceous, thickly and finely mixed with dusky; dorsum somewhat darker 
than sides, or sometimes nearly same color; subauricular tufts usually 
conspicuous, mixed white and buffy ochraceous; ears dusky, edged 
with creamy white; a small dusky spot at base of whiskers and a 
narrow dusky orbital ring; underparts creamy white; feet and fore- 
legs white; 'ankles' buffy ochraceous; tail blackish brown above, 
white below. Worn pelage : Upperparts ochraceous buff to tawny, 
varying in clearness according as the dusky of the unworn pelage is 
more or less altered and eliminated; back nearly same color as sides 
except in stages of slight wear. Adolescent pelage : Ground color of 
upperparts paler than in adults, inclining to buffy rather than tawny; 
dusky mixture heavier and more uniform ; general effect somewhat 

" Approaching .sonoriensis. 


between cinnamon and raw umber. Young in first coat : Base of hairs 
slate color (Ridgw. pi. II, No. 4); ends of hairs pale drabby fawn 
mixed with dusky brownish; general effect of upperparts mouse gray. 

Skull. — Practically as in nebrascemis and sonoriensis/ slightly 
smaller than in artemisiae; smaller and narrower than in arcticus and 
with less spreading zygomata. 

Measurements. — Average of 15 adult topotypes: Total length. 
160 (150-170): tail vertebra?, 70 (56-75); hind foot, 20 (19-21); 
ear, from notch (dry), 15.5 (14.1-16.6). Of 20 males from Manzano 
Mountains, New Mexico: 151 (144-165); 63.4 (59-77). Of 15 fe- 
males from the same locality: 156 (142-168) ; 68 (61-73). 

Type specimen. — No. Hftf U. S. National Museum, Biological 
Survey Collection. 9 adult. August 22, 1889. C. Hart Merriam 
and Vernon Bailey. Specimen in partly worn pelage, in good con- 

Remarks. — This is a mountain form, but like other members of 
the maniculatus group it variously intergrades with surrounding 
forms, and differs from them only in average characters. On the 
north it meets artemisvv. from which it differs mainly in smaller 
size and slightly more rufescent color. Specimens from Mammoth 
Springs, Yellowstone Park, in unworn winter pelage are very similar 
to typical rufinus in the same pelage from Arizona and New Mexico, 
and others from Clarks Fork, Wyoming, in partly worn pelage are 
more dusky than rufinus and very similar to artemisice, to which they 
are referred. 

On the east, intergradation with nebrascensis is evidenced by speci- 
mens from the foothill region of eastern Colorado, and in some series 
specimens which might be referred to either form are found. Pos- 
sibly, if the exact localities from which they came were known, the 
difference would be explained. Connection with sonoriensis in the 
same way is shown on the west, although in a series from Bluff, Utah, 
we find 11 specimens that are typical rufinus and one that is typical 
sonoriensis, which might seem to indicate that the two forms are dis- 
tinct. At other localities, however, there is ample evidence of inter- 
gradation, and, indeed, individual variation in each form is almost 
enough to cover the average difference between the two. Moreover. 
sonoriensis unquestionably intergrades with gambeli, which is dis- 
tinguishable from rufinus only with great difficulty. In worn pelage, 
the majority of specimens of rufinus are indistinguishable from gam- 
beli in the same pelage. This is particularly true of specimens from 
the Sierra-Cascade region, which for the present are referred to <jam- 
beli under the belief that they are nearer that form, though undoubt- 
edly tending somewhat toward rufinus. In winter pelage gambeli 
from the coast of California is more dusky and less tawny than 
rufinus. Very few specimens in winter pelage from the Sierra Ne- 


vada are available at present, but the scanty material shows somewhat 
more similarity to gambeli than to rufinus. Since, however, the dif- 
ferences are within the limits of variation, it will not be surprising 
if good series in winter pelage from the Sierra-Cascade region prove 
referable to rufinus. 

SpeciTwns examined. — Total number, 1,336, from localities as 
follows : 

Arizona: Baker Butte, Mogollon Mountains, 4; Chiricahua Mountains, 
131; Graham Mountains. 2~>; Keani Canyon. 4 (approaching sono- 
riensis) ; San Bernardino Ranch, 21 (approaching sonoriensis) : San 
Francisco Mountain, 28; Show Low, 2; Springerville, 59; Taylor, 3; 
Turkey Tanks, 3; White Mountains, 66. 

Colorado: Allenton, Eagle County, 2; a Alruont, 2; Antonito, 2; Asli- 
baugh Ranch, 2; a Arboles, 2; Bayfield, 1; Black Hawk 2; Boreas 
Pass, Summit County, 1;° Boulder, 63 (approaching nebrascensis) ; 
Boulder County, 23; Canadian Creek, 7; Canyon City, 4: Conejos 
River, 2; Cortez, 1;« Coulter, 5; Coventry. 3; Debeque, 1; Del 
Norte, 1; Durango, 4; Elkhead Mountains, 1; Estes Park. 63 (ap- 
proaching nebrascensis) ; Florida, 15; Fort Garland, 4; Glenwood 
Springs (12 miles above). 2;« Golden, 4: Gold Hill, 16 (approach- 
ing nebrascensis) ; Hermit, 2; Longs Peals. 22; McCoy, 1: Mesa 
Verde, 1; Mount McLellan, 1; Mud Springs, Garfield County, 2; a 
Naturita, 1; Nederland, 14 (approaching nebrascensis); Pagosa 
Springs, 4; Pearl, 3; Rabbit Ear Mountains, 2; Rifle, 3; Ruby Lake, 
1; Salida, 1: Santa Maria Lake, 3; Sapinero, 1; Sheephorn Pass, 
Grand County, 2; a Silverton, 4; Tarryall Creek, near Puma, 1;° 
Toponas, 2; Trinidad, 1; Uncompahgre Plateau, 3; White River 
Plateau, 3; Whiteley, 3. 

New Mexico: Abiquiu, 4; Albuquerque, 2; Amizett, 2; Ancho, 2; Ar- 
royo Hondo, 3 ; Arroyo Seco, 6 ; Aztec, 20 ; Bear Canyon, Raton Range, 
6; Bear Spring Mountains, 6; Boulder Lake, 1; Cabra Springs, 1; 
Capitan Mountains, 53; Carrizozo, 1: Chama, 10; Chama River, 2; 
Chico Springs, 1; Cienequilla, 6; Cloudcroft, 10; Copperton, 23; 
Costilla Pass, 7; Coyote Creek. 3; Datil Mountains, 25; Espanola, 
7; Fisher Peak, 1; Fort Wingate, 5; Gallina, 3; Gallinas Mountains, 
19; Gallo Canyon, 1; Gallup, 1 : Glorieta, 5: Grants, 10; Hall Peak,5; 
Hondo Canyon, 1 ; Jamez Mountains, 1 ; Jicarilla Mountains, 17; La- 
guna, 1; La Plata, 42; Las Vegas, 17; Long Canyon, near Catskill, 2; 
Manzano Mountains, 127; Mesa Jumanes, 4; head of Mimbres River, 
1; Moreno Valley, 3; Pecos Baldy, 8; Pinon Hills, 1; Ribera, 2; Rin- 
conada, 4; Rio Puerco, 1: Ruidoso, 2; Ruidoso Creek, 7; San Mateo 
Mountains, 20; San Pedro, 5; Santa Clara Canyon, 2: Sierra Grande, 
4; Stinking Spring Lake, 2; Taos, 1; Taos Mountain, 1; Taos 
Pueblo, 5; Thomkins Lake, 4; Tierra Amarillo, 2; Tres Piedras, 25; 
5 miles E. of Tularosa, 1; Twining, 8; Willis, 5; Willow Creek, 
Mogollon Mountains, 2. 

Utah: Barclay. 8; Bluff City, 16; La Sal Mountains, 1; Noland Ranch, 
20; Park City, 5; Riverview, 24. 

a Collection of E. R. Warren. 



Hesperomys leucopus nebrascensis (Baird) Mearns, Bull. Am. Mus. Nat. Hist., 
N. Y., II, p. 285, Feb. 21, 1890 — not Hesperomys sonoriensis var. nebrascen- 
sis Baird, nomen nudum, L857. 

? Hesperomys I Vesperimus) cherrii Allen, Bull. Am. .Mus. Nat. Hist., N. Y., Ill, 
pp. 211-211', Apr.. 1891— part, reference to skull only. 

Peromyscus texanus nebrascensis Allen. Bull. Am. Mus. Nat. Hist.. VIII, p. 251, 
Nov. 2.".. 1896— part. 

Type locality. — Calf Creek, Custer County, Mont. 

Geographic distribution. — Plains and foothills along the eastern 
base of the Rocky Mountains from south central Saskatchewan to the 
Panhandle of Texas, occupying- in general the eastern parts of Mon- 
tana, Wyoming, and Colorado, and the western and southwestern 
parts of Saskatchewan and the Dakotas. Upper Sonoran and Transi- 
tion zones. 

Characters. — Similar to P. m. arcticus, but color decidedly paler, 
more buffy ochraceous; size slightly smaller, tail averaging shorter 
(usually less than TO mm.) ; color nearly as in P. m. sonoriensis, buffy 
and ochraceous with slight variations predominating in all adult 
pelages, tail shorter; very similar to P. m. luteus, but larger, with 
noticeably larger ears; also similar to P. m. nip' mis, but color paler; 
somewhat similar to P. 1. arididus, but smaller, with a shorter, more 
hairy, and more sharply bicolor tail; skull smaller, with narrower 
braincase, smaller audital bullae, longer parallel-sided palatine slits, 
and smaller molar teeth. 

Color. — Unworn pelage (Sept.-Dec.) : Upperparts pale ochraceous 
buff or between cream buff and ochraceous buff, lightly and uniformly 
mixed with dusky ; back scarcely or not at all darker than sides ; under- 
pays pure creamy white; ears dusky brownish, broadly edged with 
white; subauricular tuft pure white anteriorly, nearly clear buff} 1, pos- 
teriorly, the white usually quite conspicuous; feet and forelegs white, 
'ankles' buffy or buffy and dusky; tail sharply bicolor, blackish 
brown above, white below. Worn pelage (Apr.-July) : Similar in 
general to unworn pelage but color of upperparts much brighter, 
more ochraceous; dusky mixture becoming gradually eliminated with 
increasing wear and changed to cinnamon and russet: general effect 
of upperparts varying from ochraceous buff to tawny ochraceous. 
Adolescent pelage: Most similar to unworn pelage of adult but less 
buffy; general effect of upperparts pale drab or isabella color. 
Young in first coat : Upperparts slate color at base of hairs, brownish 
smoke-gray at tips; underparts grayish white. 

Skvll. — Similar in general to that of P. m. arcticus, but averaging 
slightly smaller and narrower; nasals usually longer, narrower, and 
more convex ; braincase narrower and less arched ; zygomata not so 
heavy nor so much ' squared ' anteriorly. The skull of nebrascensis 
is essentially like those of sonoriensis and rufinus; it is larger than 
that of luteus. 


Measurements. — Average of JO adults from Fort Custer, Mont.: 
Total length L58.3 (147-170) ; tail vertebrae 63.7 (56-71) ; hind foot 
20.1 (20-21 ) ; ear from notch (dry) 14.5 ( 14-15.2). 

Type specimen. — No. 1200 American Museum of Natural History. 
New York. $ adult. October 10, 1887. W. W. Granger. The skin of 
the type is in good condition in fresh fall pelage. Its hind foot meas- 
ures dry 20.8 mm. No skull corresponding to this skin can at present 
be found in the collection of the American Museum. 

Remarks. — P. m. nebrascensis is almost identical in color with 
sonomensis and very similar in general appearance. Certain speci- 
mens of nebrascensis in partly worn pelage are deeper, more nearly 
tawny ochraceous, than any sonoriensis, and vice versa, certain much- 
worn examples of sonoriensis are paler than any nebrascensis, but 
the majority of examples of each in ordinary conditions of pelage are 
indistinguishable by color alone. 

The tail in nebrascensis averages constantly shorter than in sonori- 
ensis, though many specimens of each are fairly between the extremes. 
The skulls are somewhat variable, but the same sort of variations 
apparently occurs in each form. The color of nebrascensis is also 
very much like that of luteus, which usually may be distinguished by 
its small size, particularly by its small ears, skull, and teeth. 

P. m. nebrascensis intergrades on all sides with other forms. On 
the north it merges into arcticus, as amply proved by specimens from 
Osier and Moose Jaw, Saskatchewan. On the east it meets luteus, 
on the west and southwest rufinus and sonoriensis, and future collec- 
tions ma} 7 show its connection with blandus on the south. 

The name nebrascensis, as first used by Baird in 1857, was a nomen 
nudum and deserved no definite recognition until employed in 
connection with a description by Mearns in 1890. This has been 
discussed more fully under P. m. luteus. 

The name Hesjjeromi/s cherrii applies to a species of Reithrodon- 
tomys, but the skull of a Peromyscus indistinguishable from nebra- 
scensis was included among the specimens originally referred to it 
(see Proc. Biol. Soc, XX, pp. 50-51, Apr. 18, 1907). 

Specimens examined. — Total number G17, from localities as follows : 

Alberta: Medicine Hat, 71. 

Colorado: Baxter Pass, 3; Buford, Rio Blanco County, 1;° Colorado 
Springs, 12; near Craig, Routt County, 1;° Crested Butte. 1; 
Douglas Spring, Routt County, 1 ; " Escalante Hills, 1 ; Flagler, 1 
(approaching luteus); Four Mile Creek. 4: Fruita, 1 (immature): 
Gaume Ranch, 8 ; a Grand Junction, 3 ; Ladore, 2 : Lay, 2 ; a Lily, 2 ; 
Loveland, 35; Medano Ranch, 2; Meeker, 2; a Rangeley, 1; mouth 
of Sand Creek, Routt County, 1 : ° Snake River. 5: Steamboat 
Springs, Routt County, 2: a Valmont, 1; White River, 1: Wray, 
4; Wright Ranch. Yampa County, 1:" Yarmany Creek, near 
McCoy, 2.« 

a Collection of E. R. Warren. 


Montana: Bear Paw Mountains, 8 (approaching ruflnus) ; Big Snowy 

Mountains, 2; Birch Creek, 6; Bower, 1; Calf Creek, 5; Columbus, 
5; Fort Assiniboine, 8; Fort Custer, 26; Great Falls, 20; Jefferson 
River, Gallatin County, 1; Midvale, 4; Milk River, 3; Musselshell 
River, 2 : Little Porcupine Creek, 2; Powderville, 3: Pryor Moun- 
tains, 2 (approaching artemisice) ; Red Lodge, 2; Robare, <i; St. Mary 
Lake, 16 (approaching artemisiw) : Shelby Junction, 4: North Branch 
Sunday Creek, 1 ; Tilyou Ranch, 1. 

North Dakota: Fort Buford, 5; Glenullin, 12 (in part approaching 
Intent) ; Little Missouri River. 7. 

Saskatchewan: Crane Lake, 7: " Cypress Hills, 7; a Moose Jaw, 11; Old 
Wives Creek. 10; a Osier. Ill (approaching arcticus). 

South Dakota: Belle Fourehe, 2; Buffalo Gap, 1; Deadwood, 1; Elk 
Mountain, 9; Rapid City, 3; Xmithville, 10. 

Texas: Washburn, 10. 

Wyoming: Aurora, 10; Beaver, 1; Bighorn Basin, 2; Bighorn Moun- 
tains, 1 (approaching ruflnus?); Bitter Creek, 7: Bridger Fass, :; ; 
Bull Lake, 3; Clarks Fork, 4; Devils Tower, 2; Fontanelle, 1 ; Fort 
Bridger, 18 (approaching sonoriensis) ; Fort Fetterinan, 1 (approach- 
ing luteus) ; Fort Laramie, 1; Fort Steele, 5; Fort Washakie, 3 (ap- 
proaching sonoriensis) ; Green River, 7: Kinney Ranch, Bitter Greek, 
1; Lake Fork, 3: Little Powder River, 3; Newcastle. 10; Otto, 6; 
Powder River Crossing, 2; Sheep Creek (17 mi. W. of Toltec), 6; b 
Sheridan, 5: Sherman, 4: South Pass City, 1; Sundance, 8; Woods, 2. 


Hesperomys sonoriensis var. neorascensis Baird, Mamm. N. Am., p. 404, 1857 — 

nomen nudum. 
Hesperomys sonoriensis var. neorascensis Coues, Monogr. N. Am. Rodentia, 

p. 78, synonymy under Hesperomys leucopus sonoriensis, ~\*~1 — mentions 

specimens from Deer Creek, Nebraska. 
Peromyscus nebrascensis of authors, not of Mearns. 
Peromyscus luteus Osgood, Proc. Biol. Soc. Wash.. XVIII, p. 78, Feb. 21, 1906. 

2\>//>e locality. — Kennedy, Nebr. 

Geographic distribution. — Sandhill region of western Nebraska 
and adjoining parts of the States of Kansas, Colorado, South Dakota, 
and Wyoming. Possibly extending north to western North Dakota 
and south to western Oklahoma. 

Characters. — Similar to P. m. nebrascensis, but averaging smaller ; 
ears decidedly smaller; color more buffy ochraceous, particularly in 
unworn pelage; skull and teeth averaging smaller and lighter. 

Color. — Unworn pelage (Oct.-Nov.) : Upperparts varying from 
ochraceous buff to almost orange buff lightly and uniformly lined 
with dusky; sides like back (occasionally a bright ochraceous buff 
lateral line unmixed with dusky is found), sides of face usually a 
trifler paler; ears dusky, broadly margined with white; subauricular 
tufts white or mixed white and buffy, usually very conspicuous; 
underparts creamy white; feet white: 'ankles' white or buffy; tail 
sharply bicolor, dusky brownish above, white below. Worn pelage 

a Collection of Canadian Geological Survey. b Carnegie Museum. 


(April-July) : Similar to unworn pelage, but ground color brighter, 
dusky mixture changed to cinnamon rufous or almost entirely elim- 
inated; general effect of entire upperparts bright oehraceous buff, 
slightly paler across shoulders and often slightly tinged with cinna- 
mon rufous in middle of back. Young: Similar to P. m. nebraseensis, 
but usually slightly paler. 

Skull. — Similar to that of nebraseensis, but averaging smaller and 
lighter; teeth slightly smaller; nasals usually shorter and relatively 
broader. Extreme type of skull about as in P. m. bairdi, average 
type slightly larger. 

Measurements. — Average of 10 adults from the type locality : Total 
length 149 (1-12-158) ; tail vertebras G1.5 (56-G5) ; hind foot 19.5 
(19-20.5) ; ear from notch (dry) 12.5 (11.8-13). 

Type specimen. — No. ^ffff U. S. National Museum, Biological 
Survey Collection. ? adult. Apr. 23, 1890. V. Bailey. Specimen 
in good condition. 

Remarks. — Those familiar with P. m. bairdi (better known under 
the name michiganensis) will readily recognize I ulcus, which is 
practically identical in every respect save color. Its bright buffy 
oehraceous color easily distinguishes it from bairdi, while its small 
size separates it from nearly all other forms. In the somewhat 
brightened and worn pelages of spring and summer its color is prac- 
tically like that often shown at the same season by nebraseensis and 
sonoriensis; but in fresh fall and winter pelage it is more oehraceous 
than either of these forms. Its small size, and particularly its small 
ears, are usually safe guides in separating it from nebraseensis, which 
is the form with which it is most apt to be confused. In the center 
of its range — that is, in the sandhills of Nebraska — its characters are 
well established, but on either side intergrading specimens occur, ap- 
proaching bairdi on the east and nebraseensis on the west. Although 
the average typical nebraseensis is decidedly larger than typical 
luteus, the amount of individual variation in either form is almost 
enough to cover the two extremes. In spite of this fact, and in spite 
of fairly convincing evidence of gradual intergradation around the 
periphery of its range, typical luteus and nebraseensis sometimes 
occur together. For example, a series of 13 specimens from Elk 
Mountain, South Dakota, contains 5 that are typical of luteus and 8 
that are as typical of nebraseensis. Two specimens from Dickinson. 
N. Dak., are unquestionably referable to luteus, although the locality 
is quite removed from the general range of the form and well within 
the supposed precincts of nebraseensis. 

The name nebraseensis has been applied frequently to the form 
now called luteus, and it was doubtless intended by Baird for that 
form. This is made clear by Coues (Monogr. N. Am. Rodentia, p. 79, 
1877), who states that Baird based the name upon two specimens 


from Deer Creek, Nebraska. As used by Baird and Coues, it was un- 
questionably a nomen nudum, and so remained until Mearns redefined 
it and selected a new type belonging- to a form different from that to 
which Baird intended to apply the name. 

Specimens examined. — Total number 253, from localities as fol- 
lows : 

Colorado: Spring Canyon, near Fort Collins. ."".." 

Kansas: Hays, (i (approaching bairdi) : Logan Comity, 2; Long Island, 1; 
Pendennis, 14; Trego County, 7. 

Nebraska: Callaway, 9; Broken Bow, 1: Cherry County, 13; 10 miles S. 
of Cody, 4; Deer Creek. 1: Haigler, 8; Kennedy. 20; is miles NW. 
of Kennedy, 4 ; Perch, Rock County, 14 ; Thomas County, 1 ; Two 
Mile Lake, Cherry County, 1 ; Valentine, 1. 

North Dakota: Bottineau, 3; Dickinson, 5; Medora, 1 (identity not cer- 
tain) ; Minnewaukan, 6. 

Oklahoma: North Reaver River, T. 

South Dakota: Cheyenne River, 3; Corral Draw, Pine, Ridge Reserva- 
tion, 46; Custer (?), .';."i ; Elk Mountain, 9; "Southern Dakota, - ' 3 ; 
Spring Creek, 10: Squaw Creek. 12 (approaching bairdi). 

Wyoming: Kittle Medicine, 1." 


(PI. II. tig. 10.) 

Mus bairdii Hoy and Kennicott, in Kennicott, Agricultural Report, 1". S. Patent 

Office (1856), pp. 92-95, PI. XI, 1857. 
Peromyscus michiganensis of authors, not of Audubon and Bachman. 
Peromyscus bairdi Snyder. Pull. Wis. Nat. Hist. Soc. II. p. 116, April. 1902. 

Type locality. — Bloomington, McLean County, 111. 

Geoymphh- distribution. — Prairie region of the upper Mississippi 
Valley in southern Wisconsin, Minnesota, Illinois, Indiana, eastern 
Ohio. Iowa, Missouri, Oklahoma, and the eastern or humid parts of 
Kansas, Nebraska, South Dakota, and North Dakota ; north to 
southern Manitoba. Upper Austral and Transition zones, meeting 
the range of P. in. luteus along the border between the humid and 
the arid subdivisions. 

Characters. — Size and proportions about as in /\ ///. luteus; color 
very dark, dorsum usually black or very dark brown; ears and feet 
smaller and tail decidedly shorter than in leucopus or noveboracen- 
sis; tail more thickly haired and more sharply bicolor. 

Co/or. — Unworn winter pelage: Upperparts russet or Mars brown 
heavily mixed with black, the latter usually concentrated in the 
middle of the back; sides also heavily mixed with black, but usually 
noticeably paler than back; sides of face nearly the same as sides of 
body, somewhat paler than top of head; underparts pure creamy 

" Collection of Colorado State Agricultural College. 


white, often separated from the sides by a narrow russet lateral line; 
ears brownish black, very narrowly margined with creamy; sub- 
auricular tufts mixed russet and dusky, very rarely with a few white 
hairs; feet white, 'ankles' usually extensively blackish brown, this 
sometimes extending out on top of foot; tail sharply bicolor, black 
or blackish brown above, white below. Slightly worn pelage of 
spring: Similar to unworn pelage, but contrast between back and sides 
somewhat heightened, black predominating on the back and brownish 
russet on the sides. Summer pelage (June-July) : The extremely 
worn pelage becomes brighter, more nearly russet throughout, and 
the dark dorsal area is much reduced and changed to pale brownish. 
The short new pelage as it begins to come in is also uniform russet 
lightly sprinkled with dusky and with very little or no decided dif- 
ference between back and sides. Young: Darker than adults, black 
usually predominating, more or less modified on the sides by grayish 
broccoli brown. 

Skull. — Practically as in P. m. luteus, possibly averaging slightly 
smaller with shorter nasals. General characters as in nebrascensis, 
sonoriensis, etc., but size smaller. Compared with those of novebora- 
censis and leucopus it is much smaller; teeth, braincase. and audital 
bulla? much smaller; palatine slits relatively longer and with sides 
more nearly parallel. 

Measurements. — Two adults from Racine, Wis.: Total length 161, 
140; tail vertebrae 70, 54; hind foot 19, 18; ear from notch (dry) 
11.6, 10.6. 

Type spt cimen. — The only specimen now extant having any claim 
to consideration as the type of this form seems to be No. 750 Col- 
lection of Academy of Natural Sciences, Philadelphia. The record 
in the catalogue is as follows: " No. 750, Hesperonajx bairdii. Donor 
Dr. LeConte. Locality Illinois. Entered January, 1860/' The 
specimen now bears a red label marked "Type of Mus bairdii Hoy 
and Kennicott." This label, however, is recent, as also a white one 
which reads in the handwriting of Witmer Stone: " 750 Hesperomys 
bairdii. Illinois. Type." Mr. Stone informs me that, according to 
his recollection, these data were transcribed by him from the stand 
upon which the specimen was formerly mounted. The specimen, 
though identifiable and unquestionably of this form, is in very poor 
condition and of little interest save from a historical standpoint. 

Remarks. — Under the name michiganensis this mouse has been 
well known for years. Its small size, sharply bicolor and somewhat 
penciled tail, and its cranial characters serve to distinguish it easily 
from leucopus or noveb&racensis, while its dark color at once separates 
it from luteus and nebrascensis, to which it is really most closely 
related. It appears to be confined to the prairie or more open parts, 
including cultivated fields, of the central Mississippi Valley, while 


leucopus and noveboracensis are found in wooded parts of the same 
region. Its known eastern limit is in eastern Ohio and southern 
Ontario, but with the clearing of the land it is apparently extending 
its range to the eastward. Thus it is now found at Elk River, Min- 
nesota, as evidenced by a specimen collected by A. B. Mills in 1899, 
although some ten years earlier Vernon Bailey made large collec- 
tions there and did not secure it. 

Along the border between the humid and arid regions it inter- 
grades with P. m. luteus. Specimens from Pierre, S. Dak., are per- 
fect intermediates, and others throughout the. western part of its 
range tend more or less toward luteus. In west central Oklahoma it 
apparently intergrades with nebrascensis rather than with luteus. 
and in southern Oklahoma it probably meets P. m. pallescens, 
though the evidence in both cases is rather unsatisfactory. A small 
series from Fort Reno, Okla., are slightly paler than bairdi, but 
decidedly darker than luteus or nebrascensis; the ears are small, as 
in bairdi, but the skulls are rather large, as in nebrascensis. Speci- 
mens from Chattanooga, Oklahoma, and Belle Plain, Kans., agree 
fairly well with those from Fort Reno. A little to the westward we 
have fairly typical nebrascensis from Washburn, Tex., and to the 
eastward we find bairdi at Red Fork, Okla. Thus the Fort 
Reno specimens are intermediate in characters and in geographic 
situation, so the most logical treatment seems to be to refer them to 
bairdi, the form they most resemble. Surely nothing is to be gained 
by making such intermediate specimens the basis of new names. 

The name michiganensis was adopted for this form b}^ Baird 
(Mamm. N. Am., p. 416, 1857), who evidently was misled by the 
rather small measurements published by Audubon and Bachman for 
their supposed new species. Subsequent authors have followed Baird 
in the use of the name. A careful analysis of the original description 
of michiganensis, however, leads to the conclusion that it was based 
upon an immature example of P. I. noveboracensis, as the following 
extracts indicate: 

Mouse with yellow cheeks, a light grayish brown color above, whitish be- 
neath. This species bears some resemblance in size and colour both to the 
common house mouse (M. musculus) and the white-footed mouse (M. leucopus.) 
The colour on the back resembles the former and on the under surface the 

Hoy and Kennicott appreciated the difference between bairdi and 
michiganensis, but supposed that three forms were distinguishable. 

°Aud. and Bach., Jour. Acad. Nat. Sci. Phila., VIII, pt. II, pp. :5U4-306, 1S42. 
66268— No. 28—09 6 


This is shown by a letter from Doctor Hoy, quoted by Baird, as fol- 

I consider the difference between the oak opening deer mouse (nrichigancnsis) 
and the prairie deer mouse (bairdii) to consist mainly in the more uniform 
color, longer tail, and larger head of the former, giving to it the look more of 
the common house mouse than the latter. 

The facts of the case were suspected also by Coues, who says: 6 

There are, however, several discrepancies between the description of Audubon 
and Bachman and the characters of the animal which Hoy, Kennicott, Baird, 
and ourselves describe. * * * We fail to realize "cheeks yellow," though, 
perhaps, they are a little brighter than surrounding parts. The dimensions 
given, 4 inches for length of head and body, are so much greater (by a full 
inch) that possibly the figure "4" may be a typographical error; but then the 
tail, 2J, is nearly as much in excess of what we find. It is barely possible, 
after all, that, as Professor Baird hints, none of our specimens are what 
Audubon and Bachman called michiganensis. In that event, and if positively 
distinct from Audubon's and Bachman's animal, they would, of course, bear 
the name bairdii and michiganensis Aud. & Bach, be relegated among the un- 
numbered synonyms of lax-opus. 

Specimens examined. — Total number 334, from localities as follows : 

Illinois: Chicago, 7; Fox Lake, 1; "Illinois," 1: Parkersburg, 4; West 

Xorthfield, 4. 
Indiana: Bicknell, 2 ; c Bloomiugton, 5;°" Denver, 8. 
Iowa: Clay County, 5; Knoxville, 12; Marion County, 2; Palo Alto 

County, 4. 
Kansas: Belle Plain, 5 (approaching luteus) ; Fort Leavenworth, 2; 

Lawrence, 28; Lost Springs, 2; Manhattan, 2; Medicine Lodge, 1 

(approaching luteus) ; Onaga, 28. 
Manitoba: Aweme, 1 ; e Carberry, l. e 
Michigan: Sand Point. Huron County, 5/ 
Minnesota: Browns Valley, 2; Elk River, 1; Fort Snelling, 54. Steele 

County, 5. 
Missouri: Carthage, 3;# Independence, 1; Stotesbury. 19. 
Nebraska: Columbus, 3; Ewing, 1; Grand Island, 1; London, 5; Verdi- 
gris, 1. 
North Dakota: Devil's Lake, 13 (approaching luteus); Harrisburg, 1; 

Harwood, 3 ; Jamestown, 1 ; Oakes, 2 ; Pembina, 5 ; Portland, 10. 
Ohio: London, 2. n 
Oklahoma: Chattanooga, 2 (approaching nebrdscensis) ; Fort Reno, 7 

approaching nebrascensis) ; Mount Scott P. O., 1 (approaching 
pallescens) ; Red Fork, G. 

a Baird, Mamm. N. Am. p. 417, footnote, 1857. 

b Monogr. N. Am. Rodentia, p. 96, 1877. 

c Received for identification from E. J. Chanler. 

''Coll. Univ. of Indiana, collected by W. L. McAfee. 

p Collection of Ernest T. Seton. 

''Collection of University of Michigan. 

o Collection of H. H. T. Jackson. 

h Loaned by Prof. J. I. Hine of the Ohio State University. 


Ontario: Leamington, 2; a Point Pelee, 7.° 

South Dakota: Flandreau, 5; Fort Sisseton, 1; Travere, ): Vermilion, 4. 
Wisconsin: Beaver Dam, 12; Delavan, 3; Milton, 12; Racine, 3; Rock 
Prairie, Rock County, 2. 


(PI. II, fig. 9.) 

Peromyscus miehiganensis pallescens Allen, Bull. Am. Mus. Nat. Hist., N. Y„ 
VIII, p. 238, November 21, 1S96. 

Type locality. — San Antonio, Tex. 

Geographic distribution. — Central Texas, from the vicinity of 
the northern boundary at Gainesville south to the region immediately 
west of Corpus Christ i Bay. Lower Sonoran zone. 

Characters. — Similar to P. m. bairdi, but averaging smaller; color 
somewhat paler, less blackish. 

Color. — Topotjrpe No. 87876, $ adult. Feb. 9 : General color of 
upperparts pale russet, lightly mixed with dusky on sides and more 
heavily in middle of back; middorsal region not solid black nor 
dusky, but mixed dusky and pale russet; shoulders and nape about 
like sides; ground color nearly ochraceous buff, showing unmixed 
with dusky in the subauricular tufts and in the interfemoral region 
about the base of the tail; ears dusky, whitish edged; feet white, 
' ankles ' slightly brownish ; tail dusky brownish above, white below ; 
underparts creamy white, rather thinly overlaying pale plumbeous 
undercolor. Worn pelage: Not positively known but as indicated 
by specimens in changing pelage, chiefly pale russet varying nearly 
to Mars brown in middle of back. Young in first coat: Upperparts 
slate gray, slightly darker in middle of back. Adolescents: General 
effect of upperparts broccoli brown produced by pale fawn mixed 
with dusky. 

Skull. — As in bairdi, but averaging somewhat smaller. 

Measurements. — Average of 9 adult topotypes: Total length, 126 
(121-130) ; tail vertebrae, 51 (50-52) ; hind, foot, 16 (15-17) ; ear 
from notch (dry), 11.7 (11.2-12.7). 

Type specimen. — No. IfHf American Museum of Natural History. 
New York. $ young adult. Feb. 7, 1896. H. P. Attwater. Skin 
perfect and in full winter pelage. Skull with right audital bulla 
and right side of basioccipital broken. 

Remarks. — Except the small series from the type locality, very 
few specimens of this form have been taken. It therefore appears 
to be rare or difficult to secure, as considerable collecting within its 
range has been done recently. In color it resembles intermediates 

Collection of W. E. Saunders. Mr. Saunders writes, July 27, 1908, Unit lie 
has specimens of bairdi also from Grand Bend and the mouth of the Sauble 


between bairdi and I ulcus, such as occur in central Nebraska and 
Kansas. With the exception of P. taylori, it is the smallest member 
of the genus found in Texas and should be easily recognizable. 

As judged by rather limited material, pallescens is remarkably sim- 
ilar to P. polionotus of Georgia and Florida, differing only in slight 
cranial characters. The wide region separating their ranges, how- 
ever, is, so far as known at present, uninhabited by closely related 

Specimens examined. — Total number 14, from localities as follows : 

Texas: Alice, 1 ; Gainesville, 1 ; San Antonio, 11 ; Waco, 1. 


Peromyscus texanus Mearns, Proc. U. S. Nat. Mus., XVIII, p. 446, footnote, 

1896 — not of Woodhouse. 
Peromyscus sonoriensis blandus Osgood, Froc. Biol. Soc. Wash., XVII, p. 56, 

Mar. 21, 1904. 

Type locality. — Escalon, Chihuahua, Mexico. 

Geographic distribution. — Lower Sonoran zone of western Texas 
from the Pecos Valley westward; north along the Pecos Valley and 
other Lower Sonoran valleys of southern New Mexico to about lati- 
tude 34° north ; south in Mexico east of the Sierra Madre in Chihua- 
hua, southern Coahuila, southwestern Nuevo Leon, western Tamau- 
lipas, northwestern San Luis Potosi, Durango, and Zacatecas. 

Characters. — Similar to P. m. sonoriensis, but averaging smaller; 
tail shorter (usually less than 75); color more vinaceous; likewise 
similar to both P. m. labecula and P. m. fulvus. but somewhat smaller 
and more vinaceous. Usually dichromatic, the buff phase being quite 
similar to sonoriensis and the gray phase unique. 

Color. — Type, gray phase in winter: Upperparts pale, often whit- 
ish vinaceous buff, thickly and delicately lined with dusky, produ- 
cing a grayish drab general effect ; a narrow lateral line of vinaceous 
buff; ear tufts conspicuous, mixed white and vinaceous buff; un- 
derparts creamy white; ears dusky, rather widely margined outside 
and inside with whitish: tail sharply bicolor: feet white, 'ankles' 
with traces of dusky and buffv. Topotype No. 57644, buff phase in 
winter : Upperparts pinkish buff instead of vinaceous buff, lined with 
dusky, producing a pale cinnamon general effect; otherwise similar 
to gray phase. Worn pelages: — Gray phase: Vinaceous buff of 
upperparts paler and dusky mixture changed to cinnamon fawn in 
varying degrees, producing an ecru drab general effect. Puff phase: 
Upperparts nearly clear ochraceous buff with little or no dusky mix- 
ture. All stages of variation between the two phases occur. 

Skull. — Similar to that of sonoriensis, but averaging slightly 
smaller; nasals slightly wider and flatter; similar to that of P. m. 


labecula, but smaller and less angular; rostrum more depressed; 
zygomata more lightly built anteriorly. Cranial characters rather 
variable and more or less inconstant when applied throughout the 
range of the form. 

Measurements. — Type: Total length, 145; tail vertebra:', 61; hind 
foot, 21. Average of 7 adult topotypes: 161 (145-173) ; C8 (59-75) ; 
21.4 (21-22) ; ear from notch (dry), 14.9 (13.8-15.3). 

Type specimen. — No. 57635 U. S. National Museum, Biological 
Survey Collection. ? adult. Nov. 27, 1893. E. A. Goldman. 
Specimen in excellent condition. 

Remarks. — Any small, short-tailed mouse with conspicuous ear 
tufts and a slightly pinkish or vinaceous cast to its general color,, 
if from western Texas, southern New Mexico, or northwestern 
Mexico, may be safely referred to this form. In full winter coat it 
presents an attractive appearance, the pelage being exceedingly soft 
and the coloration very delicate. The two phases of coloration are 
very distinct and examples of both may be found in almost every 
series. Specimens in the buff phase, especially in worn pelage, are 
difficult to distinguish from sonoriensis, but the presence of one or 
more in the gray phase showing the pinkish tints not found in 
sonoriensis usually furnishes the clue to the identity of any particular 
series. In the northern part of its range, blandus is often found 
at the same localities with P. 1. tornillo, from which it is easily 
distinguished by numerous characters, among which may be men- 
tioned the following: Size smaller; tail shorter, more distinctly 
penciled, and more sharply bicolor; subauricular tufts more promi- 
nent and nearly always extensively white; nasals flatter; premaxillre 
less swollen laterally; braincase smaller. Intergradation is evident 
in the north with P. m. ruflnus and in the south with P. m. labecula. 
It meets ruflnus in the foothills of the mountains of southern New 
Mexico, and, although the line may be drawn quite sharply between 
the two forms, there is only a slight color difference' and this is 
practically bridged by the variation in ruflnus from different eleva- 
tions. Specimens from Berriozabal, Zacatecas, agree in color with 
blandus, but vary in size and cranial characters to an extent that 
covers the extremes of both blandus and labeeula. Two specimens 
from still farther south, at Lagos, Jalisco, seem referable to blandus, 
while series from Zacatecas City and Valparaiso Mountains, local- 
ities northwest of Berriozabal, are referable to labeeula, though 
possibly somewhat intermediate. 

Specimens examined. — Total number 16)2, from localities as fol- 
lows : 

Chihuahua: Chihuahua, 7; Esealon, 15; Gallego, J; .Mesquite Springs, 

near U. S. Boundary, 5. 
Coahuila: Jimulco, 1; La Ventura, 1; Saltillo, 3. 


Durango: Inde, 1; Rio Sestin, 11; Rosario, 2; San Gabriel, 2; Villa 

Ocampo, 3. 
Jalisco: Lagos, '_'. 
New Mexico: Adobe Kanch, Grant County, 1 ; near Alamogorda, Otero 

County, .'!; Animas Valley, Grant County, 1; Burley, 5; Carlsbad, 1; 

near Carrizallilo Spring, 4; Deming, 1; Dog Spring, Grant County, 

3; Hachita, 4; Hatchet Ranch, Grant County, 1; Jarilla.'l; Mesquite 

Springs, (5 ; Tularosa, 13. 
Nuevo Leon: Doctor Arroyo, !J. 

San Luis Potosi: Hacienda La Parada, 4. • 

Tamaulipas: Miquihuana, 12. 
Texas: Franklin Mountains, 1; Marathon (53 in. south), 1; Marfa, 5; 

Maxon Spring, 1; Presidio County, 2; Sierra Blanca, 3; Toyahvale, 

1 ; Valentine, 1. 
United States Mexican Boundary: Corner Monument, 100 miles west of 

El Paso, 5 ; 50 miles west of El Paso, 5. 
Zacatecas: Berriozabal, G; Canitas, 2; Plateado, 1. 


Peromyscus sonoriensis fulfils Osgood. Proc. Biol. Soc. Wash., XVII, p. 57, 
Mar. 21, 1904. 

Type locality. — Oaxaca, Oaxaca, Mexico. 

Geographic distribution. — Southeastern Mexico, in parts of the 
States of Oaxaca, Puebla, Veracruz, Tlaxcala, and Hidalgo, extending 
from Oaxaca City north to the vicinity of Pachuca, Hidalgo. Lower 
Sonoran zone. 

Character's: — Similar to sonoriensis, blandus, and labecula, but 
color darker and more rufescent ; skull about as in bland us, but an- 
terior part of zygoma usually heavier and more deeply notched by 
infraorbital foramen. 

Color. — April and May specimens : General color of upperparts 
russet, deepening in middle of back to darker (Mars brown and 
Prout brown) ; underparts creamy white; subauricular tufts promi- 
nent, butty or pale creamy; tail sharply bicolor, brown above, white 
below ; feet and forelegs white ; outer side of i ankles ' broAvnish. 
Worn pelages somewhat brighter colored, running to ochraceous and 
tawmy, but not very decidedly different from fresher pelages. Fall 
and winter pelages apparently with considerable mixture of dusky 
in middle of back. 

Skull. — Similar in general to that of bland as, but anterior part of 
zygoma averaging somewhat heavier and more deeply notched by 
infraorbital foramen; similar to that of labecula, but smaller and 
shorter; zygomata not so heavy nor so broadly expanded anteriorly; 
nasals rather short and wide. Cranial characters more or less vari- 
able throughout range. 

Measurements. — Type: Total length, 167; tail vertebra^, 68; hind 
foot, 22. Average of 10 adults from Chalchicomula, Puebla: 162 
(150-183) ; 71.5 (65-78) ; 22; ear from notch (dry) 15.5 (14.2-16.9). 


Type specimen. — No. G8G55 U. S. National Museum, Biological 
Survey Collection. $ adult. June 12, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — P. m. fulvus is the southernmost representative of the 
widely distributed m an iculatus group. In general terms it may be sa id 
to be a somewhat more brownish edition of the well-known United 
States form, P. m. sonoriensis. It does not appear to be dichro- 
matic like blandus, but it is not unlikely that future collections 
(from eastern San Luis Potosi, for example) will show that it inter- 
grades with that form. Intergradation with labecula is indicated 
by specimens from Amecameca, Mexico, which are rather dusky. 
particularly on the dorsum. The specimens, however, were taken 
in February, whereas those considered typical of fulvus were taken 
in April, May, and June, so that the darker color of the Amecameca 
series may represent merely a seasonal difference. P. m. fulvus 
might possibly be confused with P. melanotis, although it is very 
distinct. In melanotis the tail is slightly shorter, the ears are larger 
and darker, the pelage usually longer and more fluffy, and the skull 
differs noticeably in its longer, more slender rostrum. P.affinis may 
be found at the same localities with fulvus, but will be easily dis- 
tinguished by the characters of the leucopus group, particularly 
by its shorter pelage, longer, less distinctly bicolor, and practically 
unpenciled tail, and by the absence of distinct preauricular spots. 

Specimens examined. — Total number 124, from localities in Mexico 
as follows : 

Hidalgo: El Chico, 1; Irolo, 9; Pachuca, 10; Sierra tie Pachuca, •'! : Leal 
del Monte. 25; Tulancingo, 7. 

Mexico: Amecameca, 10. 

Oaxaca: Huajuapam, 2; Oaxaca, 3. 

Puebla: Chalchicomula, 17 ; Esperanza, 8. 

Tlaxcala: Apixaco, 4; Huamantla, 5. 

Veracruz: Las Yigas, 3; Perote, ."> : Cofre de Perote, 1 ; Xuehil. 13. 


PeromyscU8 labecula Elliot, Field Col. Museum, Zool. Ser., III, pp.. 143-144. 

Mar. 1903. 
Peromyscus sonoriensis labecula Osgood, Proe. Biol. Soc. Wash., XVII. p. 57, 
Mar. 21, 1904. 

Type locality. — Ocotlan, Jalisco, Mexico. 

Geographic distribution. — Southwestern and south central Mexico, 
chiefly in the States of Jalisco, Guanajuato, and Mexico. Lower 
Sonoran and Upper Sonoran zones. 

Characters. — Similar in general to sonoriensis, blandus, and 
fulvus, but size larger; color decidedly darker, more sooty; skull 
larger and more angular. 

Color. — Fresh pelage, topotype No. 12013."), December 30: Upper- 
parts fawn color heavily mixed with sooty throughout, producing a 


general effect from drab to hair brown: middle of back somewhat 
darker than sides: underparts white; feet white; forelegs with 
traces of dusky inside; 'ankles 1 extensively dusky; ears blackish, 
faintly edged with whitish; subauricular tufts mixed whitish and 
fawn strongly pervaded with sooty; tail sharply bicolor, blackish 
above, white below. Worn pelage, topotype No. 120114: Upper- 
parts chiefly fawn color mixed with rusty brownish, producing a 
general effect of nearly clear dark fawn color. Young: General 
effect of sides slaty gray; middle of back darker, slaty to almost 
black. Extreme types of coloration are more sooty, less fawn, than 
in specimens from the type locality. 

/Skull. — Slightly larger, longer, and more angular than in sonorien- 
sis, blandus, and fulvus; anterior part of zygoma very heavy and 
deeply notched by interorbital foramen ; braincase relatively small. 

Measurements. — Average of 10 adults from the type locality : Total 
length, 173 (108-182); tail vertebra?, 72 (04-82); hind foot, 22.5 
(22-24) ; ear from notch (dry), 14.9 (14.5-15.5). 

Type specimen. — No. 8093 Field Museum of Natural History. 
June, 1901. F. E. Lutz. Skin poorly made; side of head torn; feet 
slightly injured; tail vertebrae not removed from skin; skull with 
anterior part of right zygoma broken ; teeth much worn. 

Remarks. — Except in certain worn pelages, this form is always 
more or less sooty in color. It is less confined to the Lower Sonoran 
zone than blandus and fulvus and apparently enters even the Tran- 
sition, where it ranges with P. melanotic. In certain pelages it is 
often scarcely distinguishable by color alone from P. melanotis. Its 
skull, however, always preserits diagnostic characters in the shorter, 
broader rostrum, and narrower, less-rounded braincase. It ap- 
proaches, also, P. I. mesom'elas in color, but is of course distinguished 
by the numerous characters which separate the maniculatus and 
leucopus groups. 

Specimens from Etzatlan and Atemajac, Jalisco, seem to be some- 
what intermediate between Iribecula and blandus, while those from 
Ajusco, Federal District of Mexico, approach fulvus. Two speci- 
mens from Hacienda Magdalena, Colima, are tentatively referred to 
labecula, although they are very small and rufescent. Possibly they 
represent a slightly characterized coast form or an approach to 
fulvus. Several from Tepic also are small and have short, broad 
nasals and small molar teeth, but in view of the known cranial 
variability in the group and the scantiness of material, it does not 
seem wise to attempt to define such forms. 

Specimens exam hied. — Total number 152, from localities in Mexico 
as follows: 

Colima: Hacienda Magdalena, 2 (aberrant). 
Guanajuato: Irapuato, 6: Santa Rosa, 1; Silao, 1. 
Hidalgo: Ixmiquilpan, 1; Zimapan, 2. 


Jalisco: Arroyo de Plantinar, 3; Atemajac, 4: El Molino, 2; Estancia, 4; 

Etzatlan, 3; Garabotos, 1; Mascota, 1; Ocotlan, 41; Plantinar, 1; 

Sierra Nevada de Colima, 9; Zapotlan, 6. 
Michoacan : Patamban, 2; Patzcuaro, 1. 
Morelos: Huitzilac, 1 : Yautepec, ."». 
Mexico: Ajusco, 4 (not typical); Tlalpam, 8; Toluca Valley, 15; north 

slope Volcan Toluca, 2. 
Tepic: Ojo de Aguas, near Amatlan, 4; Tepic, 3. 
Zacatecas: Valparaiso Mountains, 16; Zacatecas, 5. 


Hesperomys sonoriensis Le Conte, Proc. Acad. Nat. Sci., Pbila., VI (1852-3), 

p. 413, 1853. 
Hesperomys leucopus deserticolus Mearns, Bull. Am. Mus. Nat. Hist., N. Y., II, 

pp. 2S5-2S6, Feb., 181)0 — Mohave River, 12 miles below Hesperia, Calif. 
Sitomys insoiatvs Rhoads, Proe. Acad. Nat. Sci., Pbila., pp. 256-257, Oct. 23, 

1894 — Oro Grande, San Bernardino County, Calif. 
[Peromyscus tan mix] .sonoriensis Mearns, Proc. U. S. Nat. Mus., XVIII, p. 44(3, 

Mar. 25, 1896. 
Peromyscus oresterus Elliot, Field Col. Mus., Chicago, Pub. 74, Zool. Ser., Ill, 

pp. l. r )9-l(i(», Apr., 1903 — Vallecitos, San Pedro Martir Mountains, Lower 

California, Mexico. 

Type locality. — Santa Cruz, Sonora, Mexico. 

Geographic distribution.— -Great Basin region in general. North- 
ern Sonora, southern and western Arizona and Utah, exclusive of the 
higher mountains, northeastern Lower California east of the San 
Pedro Martir Mountains, southern and eastern California east of the 
Sierra Nevada and the San Bernardino and associated ranges, prac- 
tically all of Nevada, and parts of southeastern Oregon and south- 
central Idaho. 

Characters. — Similar in general to P. m. nebrascensis ; size averag- 
ing larger, tail longer (70 to 80 mm.) ; slightly dimorphic in color, but 
less so than in blandus; predominating color in most adult pelages 
ochraceous bun; white spots at anterior base of ear usually conspicu- 
ous; color paler, less mixed with dusky than in rufinus and gambeli 

Color. — Unworn pelage, pale phase represented by No. f|lf £ U. S. 
National Museum, from Lochiel, Pima County, Ariz. : Ground color 
of upperparts ochraceous buff lightly and uniformly mixed with 
fine dusky lines; back scarcely or not at all darker than sides; under- 
pays white or creamy white; ears dusky, rather broadly edged with 
whitish; subauricular tufts chiefly ochraceous buff lightly mixed 
with dusky, but with a small tuft of pure white hairs at the anterior 
base of the ear; little or no dusky at base of whiskers and no orbital 
ring, although the eyelids may be dusky; feet and forelegs white. 
tarsal joints white, buffy, -or buffy slightly mixed with dusky; 
tail brownish dusky above, white below. Dark phase, represented 
by No. 58788 U. S. National Museum, from Santa Cruz River, 
Sonora: Similar to pale phase, but darker, often closely resembling 


normal pelages of rufinus and gambeli; ground color of upperparts 
ochraceous, or even lawny ochraceous, usually with a more or less 
vinaceous cast; dusky mixture heavier; basal color of hairs darker; 
dusky markings about face inclined to be slightly developed; white in 
subauricular tufts reduced or obsolete: "ankles' usually somewhat 
dusky. Worn pelage: Dusky mixture of upperparts much reduced 
and changed to cinnamon or russet, so that the general effect becomes 
clear ochraceous buff, lightly overcast with russet; this change is 
effected without much abrasion, so that specimens in full long pelage 
may have the predominating ochraceous buff color; in extreme wear 
the darker mixture is very pale and almost eliminated and the gen- 
eral color paler, becoming nearly cream buff or pinkish buff; the dif- 
ference between the dark and light phases in worn pelage is mini- 
mized, one being merely somewhat more vinaceous than the other. 
Adolescent pelage: Upperparts mixed dusky and pale clay color, 
general effect varying from wood brown to broccoli brown. Young 
in first coat: Upperparts slate color at base of hairs, pale drab gray 
at tips. 

Skull. — About as in that of nebrascensis, possibly averaging 
slightly larger; also similar to those of gambeli, rufinus, and blandus; 
slightly larger than in blandus and <j<iuil><li, with nasals averaging 
longer and more convex; braincase smaller and narrower than in 
arizonae or any of the leucopus group: palatine slits relatively long 
and nearly parallel-sided. 

Measurements. — Average of 10 adults from Santa Cruz River, 
Sonora: Total length 100 (152-170) ; tail vertebrae 75 (05-80) ; hind 
foot 20.7 (20-21.5); ear from notch (dry) 10.4 (15.2-17.7). Of 10 
adults from Oro Grande and Mohave, Calif.: 10-4 (150-174); 72 
(00-80): 19.8 (10-21). Of 10 adults from Panamint Mountains, 
Calif.: 105 (155-172) ; 73 (04-82) ; 20.2 (19-21). Of 10 adults from 
Vallecitos and Hanson Lagoon. Lower California (exclusive of type 
of P. oresterus): 105.8 (158-173); 76.6 ■ (71-82) ; hind foot 20.8 

Type 'specimen. — No. jV/g U. S. National Museum. Immature. 
Sex? 1851. J. II. Clarke. Skin in grayish plumbeous first coat; 
in fairly good condition, being made in proper form like a mod- 
ern skin, evidently having, been renovated after being originally 
preserved in alcohol. Pelage somewhat greasy and stained, but color 
not materially different from recent specimens in same pelage. The 
skull has been broken through the interorbital constriction and glued 
together. The braincase, audital bullae, and posterior parts of the 
skull are nearly perfect; the anterior parts are also in fair condition, 
although the boundaries of the long palatine slits are slightly broken. 
The teeth are intact, except the last left upper molar, which is absent. 
Left mandible perfect; right mandible with processes broken off. 


That this specimen is actually the typo of sonoriensis is vouched 
for by Baird (Mamm. X. Am., p. 475. 1857), who states that it was the 
basis of LeConte's name and description. Its immaturity makes the 
skin practically worthless for distinguishing- it from arizonae, which 
occurs in the same region, but the characters of its skull, particularly 
the small comparatively narrow braincase, are conclusive. 

Remark*. — The name sonoriensis as applied to some form of white- 
footed mouse is well known, perhaps almost as well as the name 
leucopus. It was recognized by Baird in 1857, and although placed as a 
synonym of leucojAis by Cones in 1877, it has had some sort of recog- 
nition for more than fifty years. Fortunately the name may now be 
applied in a general way to the same form with which it has always 
been associated. To distinguish it from nebrascensis, rufinus, gam- 
h<l i, and other forms with which it intergrades will doubtless always 
be difficult, but its short, well-haired, and sharply bicolor tail will 
separate it from most forms from which it is specifically distinct. It 
may possibly be confused with arizonae when both are found at the 
same or neighboring localities, for although sonoriensis and arizonae 
are unequivocally distinct species respectively representing" large 
groups, in certain pelages many specimens might be misidentified by 
one not thoroughly familiar with the characters of the two groups. 
The most important characters of sonoriensis as contrasted with ari- 
zonae are as follows: Size smaller; tail shorter, more hairy, and 
more sharply bicolor; white subauricular spots usually well devel- 
oped; skull smaller; braincase decidedly narrower and relatively 
deeper; palatine slits relatively longer and more nearly parallel- 
sided; mandibles more slender. 

P. m. sonoriensis ranges in general throughout the Great Basin 
region and prefers relatively arid country, although apparently it 
is absent from the hottest parts of the lower Sonoran zone, Avhere 
P. eremicus thrives. It intergrades with the large number of forms 
which range to the borders of the Great Basin, including nebrascen- 
sis, rufinus, artemisiae, hi and us, and gambeli. The differences sepa- 
rating all these forms, although undeniably sufficient, are at most 
differences in shade of color or in average size and proportions. 
Frequently the average difference in color is enough to be appreciated 
by any amateur, while nevertheless absolutely bridged by individual 
variation. It may be easily seen therefore that the certain identifi- 
cation of single specimens or even small series from border regions 
or intergrading areas is next to impossible. However, the attempt 
has been made to allocate specimens as nearly as possible with the 
forms which they seem to resemble most. Along the east slope of 
the Sierra Nevada Mountains, in the Tejon Pass region, and thence 
south along the eastern side of the San Bernardino Mountains and to 
the east of the San Pedro Martir Mountains, sonoriensis intergrades 


Willi the (linker and smaller gambeli; it meets artemisiae in central 
rdaho, where specimens occur that are colored like sonoriensis', but 
attain almost the size of artemisiae; in southwestern Wyoming and 
northern Utah it apparently intergrades with nebrascensis ; in the 
mountains of central and western Nevada and also in Utah it shows 
tendencies toward rufinus; and in southeastern Arizona, southwestern 
New Mexico, and adjacent parts of Mexico it connects with bland us; 
in northern and central Lower California it merges with coolidgei. 
The predominating color is ochraceous buff, practically like that 
of nebrascensis ; in slightly worn pelage it becomes very bright, with 
little or no dusky. The bright slightly worn specimens are usual in 
spring and early summer, but the sequence of pelages conforms less 
with season than in the more northern forms, and worn specimens 
are often taken in midwinter. The existence of tw T o phases of color, 
one darker and somewhat vinaceous and the other paler and more 
yellowish, seems to be beyond question, but the pale phase is much 
the more prevalent and the difference between the two is not nearly 
so marked as in P. m. blandus. Specimens from the Mohave Desert 
and other parts of southeastern California seem to average very 
slightly smaller than typical sonoriensis ; others from northeastern 
Lower California average slightly larger; in neither case, however, 
is the difference sufficiently marked or constant to warrant recogni- 
tion by name, particularly since series that measure slightly larger 
or smaller are found throughout the entire range. Hesperomys I. 
deserticolus and Sitomys insolatus, both from the same vicinity in 
the Mohave Desert, and Peromyscus oresterus, from northern Lower 
California, are therefore considered as synonyms of sonoriensis. 
The type of P. oresterus is evidently abnormally long-tailed, since 
the average of a series of topotypes is much smaller, being almost 
exactly the same as that of a series of typical sonoriensis. 

Specimens examined. — Total number, 1,923, from localities as 

Arizona: Adonde, Yuma County, 3; Head of Barbacornori Creek, San 
Pedro Valley, 1; Calabasas, ">; Dos Cabesos, 1; Ebrenberg, 1; Fair- 
bank, 5; Fort Huachuca, 3; Fort Mohave, 4; Gila City, 1; Grand 
Canyon, 1; Ilolbrook, 32: Huachuca Mountains, S; Locbiel, Pima 
County, G; Mohave County, opposite Needles, 19; Oracle, 1 ; Painted 
Desert, 11; Phoenix, S; San Pedro River, 5; Sonora, Pima County, 1 ; 
Willcox, 1 ; Yuma, 7. 
California: Adobe Station, 2;« Amedee, 10;° Ash Creek, 20; Bakersfield, 
1;° Banning, 4; Baregas Spring, 2; Barstow, 3; Bear Valley, San 
Bernardino County, 10 ;" Bennett Wells, 3; Big Pine Mountain, 9:° 
Bishop Creek, 3; Blue Lake, G; a Bridgeport, 1 ;° Cabezon. 1 ; Cameron, 
2 ; Cameron Lake, 1 : Carrizo Plains, 3 ;° Casa Diabolo, Mono County, 
2; a Coahuila Mountain, 1; Colorado Desert, 3; Coso, 32; Coso 
Mountains, 2; Cuyama Valley, 3; a Death Valley, 8; Fort Tejon, 20;° 
Furnace Creek, 11 : Granite Springs, 2; Grapevine Springs, 1 ; Haway 

" Approaching gambeli. 


Meadows, 6; Honey Lake, 4 ;' 7 Hope Valley, 2;" Hot Springs, Mono 
County, 2: Hot Springs Valley, 1; Independence Creek, 2; Indian 
Canyon, 4;" Inyo Mountains, 16; Keeler, 5; South Fork Kern River, 
25 miles above Kernville, 18; Kernville, r> : Leavett Meadows, Mono 
County, 1; Little Bear Valley, San Bernardino Mountains, 14 ; a Liille 
Owens Lake, 3; Lone Pine, 28; Long Valley, Mono County, 24 \ a Lytle 
Creek, 1; Mammoth, 1; Markleeville, 3;" Maturango Spring, 4; Men- 
ache Meadows, 6 ; Mesquite Valley, 1 ; Mohave, 13 ; Mohave Desert, 1 ; & 
Mohave River, 7; Mono Flats, Santa Barbara County, 3;° Mono 
Lake, 38;° Mono Fass, 5; a Morongo Pass, 13; Mount Pinos, 6;° 
Mount Whitney, 48; Needles, 26; Neenach, 4; Olancha, 11; Olancha 
Peak, 1 ; Onyx, 11 ; Oro Grande, 12 ; near Owens Lake, 6 ; head of 
Owens River, 1; Owens Valley, 12; Painted Rock, SE. of Kinnnler, 
1 ; a Palm Springs, 4; Panamint, 5; Panamint Mountains, 62; Pana- 
mint Valley, 3; Pine City, 1; Pine Creek, 4; Reche Canyon, near 
San Bernardino, 10 \ a Resting Springs, 2; Round Valley, 1; San 
Antonio Mountains, 2; San Bernardino, 7; San Bernardino Moun- 
tains, 19;° San Bernardino Valley, 21 ; San Emigdio, 6;" San Emigdio 
Canyon, 8;° San Felipe Valley, 6; San Gorgonio Pass, 1 ; San Jacinto 
Mountains, 41;" San Rafael Mountains, Santa Barbara County, 14;° 
Santiago Springs, 1;" Saratoga Springs, 7: Squirrel Inn, 6; Susan- 
ville, 3; a Tehachapi, 50 ; a near Tejon Pass, 2; a Vallecito, Colorado 
Desert, 1 ; Victor, 1 ; Walker Basin, 3 ; Walker River. Mono County, 
2;° Walker Pass, 5; Walters, Colorado Desert, 2; White Mountains, 
3; Whitewater, 4; Woodford, Alpine County, 53; Yuma, 2. 

Idaho:'' Arco. 1; Big Butte, 2: Big Lost River, 16; Birch Creek, 13; 
Blackfoot, 16; Crow Creek, 1; Lemhi, S; Montpelier Creek. 1; Pah- 
simeroi, 2 ; Sawtooth, 4 ; Sawtooth Lake, 12 ; Shoshone Falls, 5. 

Lower California: Aguaje de las Fresas, 4; Cocopah Mountains, 6; Han- 
son Lagoon, 17; Hardy River, near Volcano Lake, 4; head of Hardy 
River, 1; La Grulla, 19; Poso Vicente, 1; San Matins Spring, 1; 
Seven Wells, 9 ; Vallecitos, 20. 

Nevada: Anderson Ranch, Douglas County, 10: Arc Dome, 1 : Ash Mead- 
ows, 10; 30 miles. SW. of Austin, 3; Bijou, 2; a Bull Run Mountains 
2; d Carson, 3 ; a Carson River, 6; a Carson Sink, near Timber Lake 
3; Charleston Mountains, 11; Cloverdale, 1; Cottonwood Range, 8 
Edgewood, 4; Elko, 1; Genoa, 1; Gardnerville, 12; Granite Creek 
6; ffl Grapevine Mountains, 30; Halleck, 5; Holbrook, 3; East Hum 
boldt Mountains, 1; Indian Creek, 1; Lovelocks, 1; McDermitt, 1 
Monitor Valley, 2; Mount Siege], 228; Mount Sugar, 7; Mountain 
City, 39; d Oasis Valley, 1: Osobb Valley, 1: Pahranagat Valley. 4 
Pahrump Valley, 1; Palisade, 4; Rabbit Dole Mountains, 2; head 
of Reese River, 35; Reno, 6; a Ruby Mountains, 3 ; d Ruby Valley, 1 
near Stillwater, 14; Summit Lake, 1; Thorp Mill, 3; Vegas Valley 
11; Verdi, 8 ;« Wadsworth, 1; Washoe, 3; a White Rock Valley, 3 
Winnemucca, 1; Winter's Mine, Douglas County, 17. 

Sonora: Cienega Well, 5; Colonia Lerdo, 1; Colorado River, 20 miles S. 
of U. S. Boundary, 2; opposite mouth of Hardy River, 19; Santa 
Cruz, 4; Santa Cruz River, 2'.): Sierra de Ios Patogones, 1. 

"Approaching gambeli. 
6 Type of dcserticolus. 

c Nearly all Idaho specimens referable to sonoriensis show approach to 

d Approaching rufinus. 


United States and Mexican Boundary: Colorado River, at Boundary 
Monument No. 204, 17; S;m Luis Springs, Aniums Valley, 4. 

Utah:" Beaver Mountains (Puffer Lake), 4; Beaver Valley, 4; Browns 
Park, 2; Clear Creek, 1; Diamond Peak, 2: Fairfield, !> : Fish Lake 
Plateau, 2; Glenwood, 3 ; Hanksville, 1; Henry .Mountains (Mount 
Ellen), (5; Kelton, 2; Laketown, 3; Loa, 4; Manti, 2: Marysvale, 5; 
Nephi, 11: Ogden, 4: Panguitch, 2; Panguitch Lake, 2; Parawan 
Mountains (Brian Head), 2; Provo, 0; St. George, 4; Salt Lake 
City, 13; Santa Clara, 3; Santa Clara Creek, 1; Uncouipahgre Indian 
Reservation, 11. 


Peromyscus leucopus coolidgei Thomas, Ann. & Mag. Nat. Hist., ser. 7, I, p. 
45, Jan. 1898. 

Type local it;/. — Santa Anita, Lower California, Mexico. 

Geographic distribution. — Greater part of the peninsula of Lower 
California from Cape St. Lucas northward to the vicinity of the 
southern base of the San Pedro Martir Mountains. 

Characters. — Size slightly larger than in P. m. gambeli, about as in 
P. m. sonoriensis; color decidedly paler and mere ochraceous than in 
gambeli, paler even than in sonoriensis ; subterminal zone of hairs of 
upperparts very pale and usually considerably exposed in worn pel- 
ages; color somewhat dimorphic as in. P. n>. blandus. 

Color. — Similar to that of sonoriensis but averaging slightly paler, 
especially in worn pelage. Unworn pelage, buff phase : Upperparts, 
head, and sides ochraceous buff lightly and uniformly mixed with 
dusky, producing a general effect very near to clay color; lateral line 
scarcely evident; ears broadty whitish distally, white spots at anterior 
bases conspicuous; underparts pure white; feet, forelegs, and tarsal 
joints white; tail sharply bicolor, grayish brown above, white below. 
Worn pelage, buff phase: Upperparts bright ochraceous buff very 
lightly mixed w T ith cinnamon on back and rump, becoming pinkish 
buff on shoulders wdiere the pale subterminal zone of the hairs is 
more exposed ; face and nose usually pale, varying from pinkish buff 
to ochraceous buff; white spots in front of ears slight or obsolete. 
Unw r orn pelage, gray phase: Upperparts pale salmon buff to pinkish 
buff mixed with dusky, producing a general effect approaching ecru 
drab; otherwise about as in buff phase. Worn pelage, gray phase: 
General effect of upperparts pale whitish ecru drab lightly. touched 
with cinnamon; pale whitish buff subterminal zone of hairs variously 

iSkull. — Rather variable, but not definitely distinguishable from 
that of sonoriensis; possibly averaging slightly smaller. 

Measurements. — Average of 7 adults from Santa Anita, San Jose 
del Cabo, and Cape St. Lucas, Lower California: Total length, 171 

° Mostly approaching ruflnus. 


(162-178) ; tail vertebrae, 82 (79-86) ; hind foot, 21 ; ear from notch 
(dry), 1G.3 (15.4-18). Average of ten adults from Santo Domingo, 
Lower California: Total length, 104 (158-171); tail vertebrae, 75 
(70-78) ; hind foot, 21.9 (21.5-22). 

Type specimen. — In British Museum. Collected May 21, 1896, by 
Dane Coolidge. Specimen in good condition. 

Remarks. — Considering its distribution, it is perhaps strange that 
this form is not more decidedly different from P. m. sonoriensis. 
The most that can be said is that it averages paler. Many specimens 
are almost indistinguishable, particularly from the sonoriensis 
found in southeastern California. These, which have received the 
name l deserticolus,' > may perhaps be regarded as in a slight degree 
intermediate between true sonoriensis and coolidgei. In worn pelage, 
coolidgei is very pale and the head and shoulders are usually of a. 
whitish cast never seen in sonoriensis. Intergradation with sonorien- 
sis and gambeli apparently takes place in the San Pedro Martir 
region. In this region, specimens partake of the characters of all 
three of the surrounding forms, gambeli, sonoriensis, and coolidgei. 
Unfortunately, two names, ' thurberi^ and ' oresterusj were based on 
specimens from this region, and as neither can be characterized they 
are synonymized with the forms they resemble most closely. The 
series representing ' thurberi^ seems to average more like gambeli 
while that representing ' oresterus ' is practically indistinguishable 
from sonoriensis. They are from localities not far apart, and when 
specimens in all pelages are available, they may prove to be alike, but 
at present the only course seems to be to dispose of them as above. 

Specimens examined. — Total number 114, from localities as fol- 
lows : 

Lower California: Agua Dulce, 1; Calamahue, 9; Cape St. Lucas, 8; 
La Paz, 9; riaya Maria Bay, 9; Pozo San Augustin, 7; Rosario, 1 
(approaching sonoriensis?); San Andres, 6; San Fernando, 3 (ap- 
proaching sonoriensis); San Francisquito, 4; San Ignacid, 4; 20 
miles west of San Ignacio, 1 ; San Jose del Cabo, 11; Santa Anita. 4: 
Santa Rosalia Bay, 15; Santo Domingo, 14; Turtle Bay (=San Bar- 
tolome Bay), 8. 


Type from Margarita Island, off west coast of southern Lower California, 
Mexico. No. 146958, I T . S. National Museum, Biological Survey Collection. 
$ adult. Dec. 1, 1905. E. W. Nelson and E. A. Goldman. 

Geographic distribution. — Known only from Margarita Island. 

Characters. — Size and general characters about as in P.m. coolidgei, 
color decidedly paler, upperparts chiefly pale pinkish bnti": skull 
short and broad. 

Color. — Unworn pelage: Upperparts, sides, and head pinkish 
buff lightly lined with dusky, the latter scarcely modifying the gen- 


eral effect; sides of face, including - base of whiskers, nearly clear 
pinkish buff; eyelids very slightly dusky; ears thinly clothed basally 
and more thickly distally with whitish hairs, membranous part of 
ears whitish basally and dusky distally; white spots at anterior bases 
conspicuous; underparts, nose, feet, and fore and hind legs white; 
hairs of throat white to roots, those of remainder of underparts with 
slaty basal zone relatively narrow; tail sharply bicolor, narrowly 
dusky above, white below. Worn pelage: General effect of upper- 
parts very pale pinkish buff; head and shoulders distinctly whitish, 
produced by the exposure of the subterminal zone of the hairs; upper 
side of tail sometimes whitish all around on distal third. 

Skull. — Similar in general to that of P. m. coolidgei, but averaging 
shorter and wider; nasals rather short and very wide. 

Measurements. — Average of 10 adult topotvpes: Total length 163 
(157-168); tail vertebra? 77 (74-81); hind foot 21.3 (20-22); ear 
from notch (dry) 16.5 (14.6-17.5). 

Remarks. — This mouse w T as found by Nelson and Goldman only on 
a strip of light-colored sand beach on the west side of Margarita 
Island. It was not obtained on other parts of the island where 
trapping was done. In color it is almost identical with P. nivei- 
ventris, which is found on similar beaches on the coast of Florida, 
and thus affords an excellent example of the development of like 
characters under like conditions. Although quite isolated and well 
characterized, this form seems best treated as a subspecies, since it 
is obviously derived from the mainland coolidgei, in which variation 
in the direction of margaritm is considerable. 

Specimens examined. — Total number 19, all from the type locality. 


Peromyscus texamus dementis Mearns, Proc. IT. S. Nat. Mus., XVI II, pp, 
44C.-i47, Mar. 25, 1900. 

Type locality. — San Clemente Island, off coast of southern Cali- 

Geographic distribution. — Outer islands of the Santa Barbara 
group, off the coast of southern California, including San Clemente, 
Santa Barbara, San Nicolas, Santa Ivosa. and San Miguel islands. 

Characters. — Similar to P. m. gambeli, but averaging slightly 
larger and darker. 

Color. — Similar to that of P. m. gambeli, but averaging slightly 
darker; ochraceous buff lateral line more distinctly marked; unworn 
pelage slightly darker, more vinaceous, and more mixed with dusky; 
worn pelage slightly deeper, more reddish colored. 

Skull. — Similar to that of P. m. gambeli. but averaging slightly 
larger, and a trifle more elongate; teeth slightly heavier. 


Measurement*. — Average of 10 adult topotypes: Total length 164 
(156-172); tail vertebrae 74 (68-78); hind foot 20.6 (20-21.5); ear 
from crown 15.2 (14.5-16) ; ear from notch (dry) 15.3 (14-17). 

Type specimen. — No. < > 1 1 1 7 U. S. National Museum. $ adult. 
Aug. 27. L894. E. A. Mearns. Specimen in good condition. 

Remarks. — This form, which occupies the outermost of the Santa 
Barbara Islands, is more closely similar to gambeli, 1 he mainland 
form, than is catalinae, which occupies the nearer islands. The 
slight characters which distinguish it from gambeli, though not 
evident in every specimen, are observable in the majority of every 
series. Such exceedingly slight peculiarities as are found in each 
of the series from individual islands are scarcely tangible, so the 
most satisfactory arrangement seems to be the reference of all from 
the outer islands to one form. 

Specimens examined. — Total number 136, from localities as follows: 

California: San Clem en te Island, 54; San Miguel Island, 25; San Nico- 
las Island, 22; Santa Barbara Island, 2'»; Santa Rosa Island, 15. 


Peromyscus catalinae Elliot, Field Col. Mus., Chicago, Zool. Sit., Ill, p. 160, 
April, 1903. 

Type locality. — Santa Catalina Island. Santa Barbara group, off 
the coast of southern California. 

Geographic distribution. — Santa Catalina and Santa Cruz islands, 
Santa Barbara group, off the coast of southern California. 

Characters. — Similar to P. m. dementis, but larger; ears larger; 
tail longer and coarser; skull larger and heavier. 

Color. — About as in P. m. dementis; slightly darker and more 
vinaceous than in P. m. gambeli. 

Skull. — Similar to that of /'. m. dementis, but decidedly larger 
and heavier; zygomata very heavy and deeply notched anteriorly; 
nasals very broad and slightly concave anteriorly; audital bullae 
actually and relatively larger: molar teeth large. 

Measurements. — Type: Total length 176: tail vertebra 3 92; hind 
foot 23; ear from notch 18. Average of ten adults from Santa Cruz 
Island: 196 (185-214); 96 (88-105): 22 (21-23); 15.7 (15-16.8). 

Type specimen. — No. 11017 Field Museum of Natural History, 
Chicago. $ adult. Feb. 6, 1903. J. Rowley. Skin in good con- 
dition ; skull with vault of cranium broken. 

Remarks. — This form differs decidedly from P. m. gambeli, and 
fully adult specimens almost equal P. boylei in size and length of 
tail. Most of the specimens available are in ragged worn pelage, 
so that it is difficult to ascertain to what degree the form may be 
characterized by color, but apparently it does not differ greatly, if 

66268— No. 28—09 7 


at all, from P. m. dementis. Specimens from Santa Catalina and 
Santa Cruz islands appear to be practically identical, notwithstand- 
ing the fact that both islands are nearer to islands inhabited by 
P. m. dementis than to each other. The Santa Cruz Island speci- 
mens appear to have slightly smaller ears than those from Santa 

Specimens examined. — Total number 50, from localities as fol- 
lows : 

California: Santa Catalina Island, 25; Santa Cruz Island, 25. 


Peromtyscus dublus Allen, Bull. Am. Mus. Nat. Hist., N. Y., X, pp. 157-158, April 
12, 1S9S. 

Type locality. — Todos Santos Island, off west coast of northern 
Lower California, Mexico. 

Geographic distribution. — Known from Todos Santos and Coro- 
nados islands off west coast of northern Lower California, Mexico. 

Oharacters. — Size large, decidedly larger than P. m. gambeli; hind 
foot equaling that of P. m. catalinae, tail and ears relatively shorter; 
color dark. 

Color.- — Similar in general to that of gambeli, catalinae, and geroni- 
mensis but darker and richer. Worn pelage: General effect of sides 
and rump rich russet, becoming nearly Mars brown in middle of 
back ; head and shoulders cinnamon to russet, slightly grizzled with 
dusky; ears dusky brownish, rather broadly edged with whitish; 
underparts buffy white; tail sharply bicolor. 

Skull. — Large and heavy, nearly or quite equaling that of catcdinae 
and decidedly exceeding that of gambeli; posterior palatine fora- 
mina very large; zygomata slightly notched anteriorly; teeth rela- 
tively large. 

Measurements. — Average of 5 adult topotypes: Total length, 186 
(176-195) ; tail vertebra?, 81 (77-02) ; hind foot, 21 (20-22) ; ear from 
notch- (dry), 15.5 (14.6-17.4). 

Type specimen. — No. y-ff f f American Museum of Natural History, 
New York. $ adult. Mar. 11, 1897. A. W. Anthony. Specimen 
in good condition. 

Remarks. — The mice of the maniculatus group on the islands off 
the west coast of southern and Lower California are all of one gen- 
eral type and all differ from the mainland form gambeli in being 
larger and more robust. The distinctions separating the various 
forms in this insular series are slight. Beginning at the north, cata- 
Unae is distinguished chiefly by its long tail and ears; next comes 
dubhis, in which the tail is slightly shorter and the color darkest 
of all ; then follows geronimensis, which is very like dubius except 


in its paler color, .and then cineritius, which is the palest form. Any 
one of these forms may be separated from gambeli by larger size. 
Specimens from the Coronados Islands are exactly like topotypes 
of dubius in color, and their skulls differ only in having the zygo- 
mata slightly less notched anteriorly. 

/Specimens examined. — Total number 68, from localities as follows: 
Lower California: Coronados Islands. 45; Todos Santos Island, 23. 


Peromyscus geronimensis Allen. Bull. Am. Mus. Nat. Hist., N. Y., X, p. 156, Apr. 
12, 1898. 

Peromysous exiguus Allen, supra cit. i>. 157 — San Martin Island, Lower Cali- 

Type locality. — San Geronimo Island, off west coast of Lower 
California, Mexico. 

Geographic distribution. — Known from various islands off the 
west coast of the northern half of Lower California, including San 
Martin, San Geronimo, and Natividad islands. 

Characters. — Similar in size and general characters to P. m. dubius, 
but color paler; similar in color to P. m. grambeli, but size decidedly 

Color. — About as in gambeli, possibly averaging slightly paler, 
thus approaching the color of sonoriensis; upperparts, head, and 
sides ochraceous buff, lightly and uniformly mixed with dusky; ears 
extensively whitish distally, brownish dusky proximally; white spot 
at anterior bases usually prominent ; underparts creamy white ; feet 
white, without dusky markings on tarsal joint ; tail sharply bicolor. 

Skull. — Rather variable, but averaging practically as in P. m. 

Measurements. — Average of 10 adult topotypes: Total length, 178 
(170-182) ; tail vertebra?, 81 (79-85) ; hind foot, 22.1 (21-23) ; ear 
from notch (dry), 16 (14.5-17.3). Average of 10 adults from San 
Martin Island: Total length, 170 (163-181); tail vertebra?, 78.5 

Type specimen. — No. Iffio American Museum of Natural History. 
New York. $ adult. March 17, 1897. A.W.Anthony. The above 
is the number originally published as that of the type but the speci- 
men now bearing a type label does not have this number. 

Remarks. — This form agrees with dubius and cineritius in size 
and proportions but differs in color, being paler than dubius and 
decidedly less grayish and more ochraceous than cineritius. Speci- 
mens from San Geronimo Island have skulls with nasals averaging 
slightly more slender than in those from San Martin Island, but 
variation is so great that there seems to be no safe basis for separa- 


lino; them. Specimens from Natividad differ only in a slight ap- 
proach toward the paleness of cineritius. 

Specimens examined. — Total number 220, from localities as follows : 

Lower California: Natividad Island, 21 ; San Geronimo Island, 142; San 
Martin Island. 57. 


Peromyscus cineritius Allen, Bull. Ann Mns. Nat. Hist., N. Y.. X, p. 155, April 

12, 1S9S. 

Type locality. — San Roque Island, off Lower California, Mexico. 

Geographic distribution. — Confined to San Koque Island. 

Characters. — Size, proportions, and cranial characters about as in 
geronimensis; color slightly less dusky and general effect much 
grayer; buffy ochraceous tints minimized. 

Color. — Unworn pelage: General effect of upperparts pale drab 
(Ridg. PL III, No. 18) ; ground color pale ecru drab uniformly mixed 
with dusky; lateral line scarcely evident except in interfemoral 
region about the base of the tail, where it is fairly well marked and 
of a rather lively pinkish buff color; a very small dusky spot at 
base of whiskers; orbital ring scarcely evident, or, at most, confined 
to the eyelids; ears dusky rather broadly edged with whitish; under- 
pays yellowish white; tail sharply bicolor, dusky brownish above, 
white below; feet white with a dusky marking on the tarsal joint. 

Skull. — Practically as in geronimensis; braincase apparently 
slightly lower and flatter; zygomata possibly more angular an- 

Measurements. — Type: Total length 191; tail vertebrae 83; hind 
foot (dry) 21.8. Average of three adult topotypes: Total length 175 
(171-184) tail vertebra? 76 (75-78). 

Type specimen. — No. yfill? American Museum of Natural His- 
tory, New York. $ adult. June 21, 1897. A. W. Anthony. Skin 
in fair condition. Skull in good condition but molariform teeth 
absent except right ml and left nil and m2. 

Remarks. — This is one of the best marked of the Pacific Coast in- 
sular forms. It is readily distinguishable from all others known, by 
its pale grayish-drab color. The color is somewhat similar to that 
of adolescents of other forms, but no specimens are at hand that are 
exactly like it. It may possibly possess certain average cranial char- 
acters, but with a very limited representation of it, this can not now 
be determined. 

Specimens examined. — Total number 9, all from the type locality. 



Type from Magdalena Island, off west coast of southern Lower California, 
Mexico. No. 146971 U. S. National Museum, Biological Survey Collection. 
$ old. Dec. 3, 1905. E. W. Nelson and E. A. Goldman. 

Geographic distribution. — Magdalena Island and a narrow strip 
of the adjacent mainland of the peninsula of Lower California. 

Characters. — Most similar to P. m. geronimensis, but larger and 
with a slightly longer tail; color slightly darker and more tawny; 
decidedly larger and darker than in coolidgei and margaritae. 

Color. — Similar to that of P. m. geronimensis, but averaging 
slightly darker and more tawny. No. 14(3972, slightly worn pelage: 
Upperparts between ochraceons buff and vinaceons cinnamon lightly 
mixed with dusky, the latter somewhat heavier on dorsum ; face and 
head very slightly paler than sides; eyelids dusky; ears dusky 
broadly edged with white; underparts creamy white. 

Skull. — Practically as in P. m. geronimensis ; braincase averaging 
slightly broader; zygomata not so deeply notched anteriorly. 

Measurements.— Average of 7 adult topotypes: Total length 181 
(175-200) ; tail vertebrae 88 (82-96) : hind foot 22.8 (22-23) ; ear 
from notch (dry) 16.6 (15.5-17.8). 

Remarks. — Although the characters are slight, the isolation of 
this form seems to warrant recognition. The form is apparently 
surrounded by P. m. coolidgei, from which it is quite distinct, while 
it is very similar to the isolated and geographically distant geroni- 
mensis. It occurs on the mainland of the peninsula as well as on the 
island, and quite probably intergrades with coolidgei. The island 
is but narrowly separated from the peninsula and at low tide the 
amount of intervening water is said to be so little at some points 
as to be easily fordable. 

Specimens examined. — Total number 19, from localities as follows: 

Lower California: Magdalena Island, 9; Matancita, 2; San Jorge, 7; 
San Juanico Bay, 1. 


(PI. II, fig. 7.) 

Peromyscus sitkensis Merriam, Proc. Biol. Soc. Wash. NT, p. 223, July 15, 1S97. 

Type locality. — Sitka, Baranof Island, Alaska. 

Geographic distribution. — Baranof and Chichagof islands, Alaska. 

Characters. — Similar in color and general characters to hylaeus 
and macrorhinus but decidedly larger than either, though exceeding 
macrorhinus much less than hylaeus; skull very large and heavy, 
larger than that of any other species of the subgenus Peromyscus 
found north of Mexico. 


Color. — Much as in macrorhinus, hylaeus, keeni, etc. Worn pe- 
lage : Sides rich russet or Mars brown, shading on dorsum to Prout 
brown and sometimes burnt umber; dusk}' markings about face, fore- 
arms, and ankles well developed ; very little or no white at anterior 
bases of ears. Adolescent pelage: General effect on sides isabella 
color lightly tinged with dusky ; dorsum usually darker than sides. 

Skull. — Most similar to that of macrorhinus, from which it differs 
chiefly in larger size; nasals and rostrum very long; zygomata some- 
what compressed anteriorly; teeth rather large; audital bullae rela- 
tively small. 

Measurements. — Average of ten adult topotypes: Total length 
224; tail vertebras 113.G; hind foot 2G.5; ear from notch (dry) 16.5 

Type specimen. — No. 73809 U. S. National Museum, Biological 
Survey collection. $ adult. July 30, 1895. C. P. Streator. Speci- 
men in good condition. 

Remarks. — P. sitkensis is closely allied to the species maniculatus, 
and though apparently distinct, extremes of variation show a marked 
approach to macrorhinus. From present material, however, it seems 
that the ranges of macrorhinus and sitkensis are not continuous, and 
it is therefore probable that if sitkensis intergrades with any member 
of the group it is with hylaeus. P. m. sitkensis is decidedly the lar- 
gest member of the maniculatus group, and in other groups 
found north of Mexico it has no rival in size except P. californicus i 
with which close comparison is not necessary. Specimens from 
Chichagof Island are almost identical with topotypes, merely aver- 
aging a trifle smaller. 

Specimens examined. — Total number 54, from localities as follows: 

Alaska: Sitka, Baranof Island, 35; Tenakee Inlet, Chichagof Island, 19. 

Peromyscus prevostensis Osgood, N. Am. Fauna No. 21, pp. 29-30, Sept. 1901. 

Type locality. — Prevost Island, Queen Charlotte Group, British 

Geographic distribution? — Prevost Island. 

Characters. — Similar to sitkensis, but with slightly shorter tail and 
slight cranial characters. Somewhat similar to macrorhinus, but 
hind foot longer and tail shorter; skull decidedly larger and heavier. 

Color. — Similar iositkensis and macrorhinus, but averaging slightly 
darker. Sides rich Mars brown shading into a broad irregular area 
of mummy brown on dorsum: dusky orbital ring and spot at base 
of whiskers very broad and scarcely separated, sometimes contiu- 


ent ; ears dusky, narrowly edged with whitish, no white at anterior 
bases; underparts grayish white, occasionally with a faint wash of 
pinkish buff on middle of breast ; forearms to wrist same color as 
sides, hands white ; ' ankles ' dusky brownish posteriorly or some- 
times all around; hind feet usually white, lightly washed with dusky 
brownish to bases of toes; tail dark brown above, white below. 

Skull. — Similar to that of sitkensis, but slightly heavier; nasals 
averaging shorter and not so attenuate posteriorly; posterior pala- 
tine foramina nearly or fully twice as long as in sitkt nsis, forming 
distinct slits rather than nearly round punctures. 

Measurements. — Average of 47 adult topotypes: Total length 217 
(205-230) ; tail vertebne 104 (97-llC>) ; hind foot 26 (25-27) ; ear 
from notch (dry) 15.6 (14.4-10.4). 

Type specimen. — No. 100818 U. S. National Museum, Biological 
Survey collection. 2 adult. July 5, 11)00. W. H. Osgood and 
E. Heller. Specimen in good condition. 

Remarks. — Since this form was described, 2 specimens referable to 
it have been received from Forrester Island, Alaska, a small islet off 
the southwest coast of Prince of "Wales Island. Specimens of typical 
sitkensis also have been obtained from Chichagof Island, Alaska. 
The known distribution of sitkensis and its one closely allied sub- 
species is therefore curiously interrupted and quite independent of its 
nearest relatives (macrorhinus, hylaeus, and keeni), although so far 
as yet known sitkensis wherever found occurs alone. Thus in the 
long distance from Baranof and Chichagof islands to Forrester 
Island are several islands inhabited apparently by hylaeus alone. In 
the same way the large islands of the Queen Charlotte group (Gra- 
ham and Moresby) inhabited only by P. m. keeni intervene between 
Forrester Island and Prevost Island. 

Specimen* examined. — Total number 49, from localities as follows: 

Alaska: Forrester Island, 2. 

British Columbia: Provost Island, Queen Charlotte Islands, 47. 

Key to subspecies of Peromyscus polionotus. 

a. Hairs of underparts chiefly white to roots. 

b. Size smaller; total length usually loss than 130; color slightly darker. Western 

1. Nose with a white stripe; or it* not, thighs white all around P. p. albifrons 

2. Nose without white stripe; thighs fulvous on inner side /'. p. rhoadsi 

bb. Size larger; total length usually more than 130; color slightly paler. Eastern 


c. Color very pale; white of underparts usually reaching lower border of eye; 

white spots above eyes conspicuous. Anastasia Island--/'. />. phasma 

cc. Color not so pale; white of underparts usually not reaching lower border of 

eye; white spots above eyes usually obsolete. Mainland of Florida. 

/'. p. niveiventris 
aa. Hairs of underparts chiefly slaty at bases P. polionotus 



(PL II, flg. 11.) 

Mus polionotus Wagner, ArcMv. f. Naturg. v. Wieg., II, i>. 52, 1.s4.°,. 

Sitomys niveiventris subgriseus Chapman, Bull. Am. Mus. Nat. Hist., N. Y., 

V. p. 341, Dec. 22, 1893. 
Peromyscus subgriseus subgriseus Bangs, Proc. Post. Soc. Nat. Hist., XXVIII, 

p. 200, March, 1898. 
Peromyscus subgriseus arenarius Bangs, supra cit., pp. 202-203, 1S98 — Hursman 

Lake, Scriven County, Georgia — not /'. eremicus arenarius Mearns 1896. 
Peromyscus subgriseus baliolus Bangs, Science, N. S., VIII, pp. 214-215, Aug. 

19, 189S — new name for /'. s. arenarius Bangs, preoccupied. 
Peromyscus polionotus Osgood, Proc. Biol. Soc. Wash., XX, p. 4!>, 1907. 

Type locality. — Georgia. 

Geographic distribution. — Open fields of the interior of northern 
Florida and southern Georgia. 

Characters. — Similar in general to P. m. pallescens and P. rn. 
bairdi, but even smaller — much smaller than any other species of the 
Atlantic States. Hairs of underparts slaty gray at base except on 
chin and throat where they are white to roots; tail definitely bicolor. 

Color. — Unworn pelage: Upperparts nearly uniform brownish 
fawn; ground color dark fawn finely mixed with brownish dusky 
which is slightly concentrated on dorsum; sides of face and orbital 
region inclining to brighter fawn; narrow 7 orbital ring dusky; ears 
dusky, whitish edged, decidedly darker than in niveiventris; sub- 
auricular tufts fawn and whitish or entirely like rest of upperparts; 
feet and forelegs white; underparts creamy white, hairs white to 
bases on chin and throat, slaty gray at bases elsewhere ; tail decidedly 
bicolor, dusky brown above, white below. Worn pelage : Sides be- 
tween fawn and cinnamon, rather brighter than either; back darker, 
almost Prout brown ; otherwise similar to unworn pelage. Ado- 
lescent pelage : Sides broccoli brown tinged with fawn, nearly like 
ecru drab, middle of back much darker, blackish hair brown. 

Skull. — Similar in general to that of P. m. bairdi, but slightly 
shorter; palatine slits in particular, shorter; audital bulla? slightly 
larger; skull incomparably smaller than that of P. gossypinus or 
any other species of the Atlantic coast region. 

Measurements. — Average of 5 adults from Gainesville, Fla. : Total 
length, 130 (125-137); tail vertebrae, 47 (41-52); hind foot (dry), 
16.6 (15.6-17.7) ; ear from notch (dry), 13 (12-13.4). Average of 10 
adults from Hursman Lake, Georgia: 126; 46.5; 16.5. 

Type specimen. — Wagner's original type of this species, as else- 
where stated (Proc. Biol. Soc. Wash., XX, p. 49, 1907), is still 
mounted and on exhibition in the museum of the Polytechnic in 
Zurich, Switzerland. Considering its long exposure, it is fairly well 
preserved, and its identity with the mouse that has been currently 
known as subgriseus is obvious. The color is not greatly changed, 


the back being dull brownish and the sides tinged with fawn, while 
the narrow whitish edgings on the ears are still evident, and the 
underparts are white. The skull is contained in the skin, and the 
ungrooved upper incisors are plainly visible. The tail vertebrae also 
are present. The rough measurements of the mounted specimen are: 
Head and body. 55.5; tail vertebra-. 33; hind foot, 17.0; ear from 
notch, 10. On the stand are several labels pasted one upon another. 
The outer and most recent one is inscribed " Mus polionotus. Grau- 
riickige Maus. X. Amerika." On removing this the next was ex- 
posed as follows: " Mus polionotus. Die grauriickige Maus. Xor- 
damerika. Georgien." This was in the hand of a museum director, 
who I was informed had died in 1865. The undermost label was 
not fully legible, but the following in the hand of Schinz could be 
seen: "Mus poliono- Nordamer." It would seem therefore that this 
specimen must be the one examined and named by Wagner in 1843. 
A few lines by Schinz" bearing on the question are as follows: 
" Diese kleine Maus ist neu. Wagner benannte sie nach dem im 
Zurcher Museum befindlichen Exemplar." 

Remarks. — P. polionotus is the representative of a small group of 
closely allied forms, all of very small size and of limited distribu- 
tion in Florida and Georgia. As a group it is so distinct from all 
its congeners of the Atlantic slope as not to require close comparison. 
Its relationship seems to be with the maniculatus group, as repre- 
sented b}' bairdi and pallescens. P. polionotus is very similar to 
pallescens, and if their ranges were continuous intergradation might 
well be expected. 

Although niveiventris and phasma are slightly larger and ap- 
parently isolated from the smaller polionotus and rhoadsi, the rela- 
tionship of all four is so close that it seems best to treat, them as 
subspecies. Specimens from Gainesville, Fla. {subgriseus) , are in- 
termediate in color between niveiventris and polionotus, and the dif- 
ference in size is so slight and so nearly bridged by individual varia- 
tion that it seems very probable that intergradation to the last de- 
gree will yet be found. 

Specimens examined. — Total number 108, from localities as fol- 
lows : 

Florida: Bliteh Ferry. 1 ; Gainesville, 45. 

Georgia: Butler, 24; 'Georgien,' 1 (type) : Hursman Lake, .°>7. 


Hespcrmiijix niveiventris Chapman, Bull. Am. Mus. Nat. Hist.. N. Y., II, p. 117, 

June, 1889. 
PeromijsvH.s niveiventris Bangs, Proc. Biol. Soc. Wash., X, p. 122, 1896. 

Type locality. — East Peninsula, opposite Micco, Fla. 
a Syn. Mamm., II, p. 177, 1845. 


Geographic distribution. — Sandy beach region of the eastern 
coast of Florida. 

Characters. — General characters much as in polionotus but size 
slightly larger and color paler; color of upperparts chiefly pale 
ochraceous buff, underparts creamy white to roots of hairs. 

Color.— Unworn pelage: Ground color of upperparts pale ochra- 
ceous buff, brighter on head and back and paler across shoulders 
and nape; upperparts with a fine delicate mixture of brownish 
dusky throughout but not greatly modifying the buffy which domi- 
nates the general effect; underparts pure creamy white to roots of 
hairs; white of underparts extending well up on sides, sometimes 
produced so as to reach the lower edge of the eye; white of sides 
near lateral line not extending to roots of hairs which are slaty 
gray at base like those of the upperparts; ear conch dusky, thinly 
clothed with buffy white hairs; subauricular tufts chiefly buffy, but 
with a few dusky and a few white hairs; feet and fore legs white; 
hind legs white except a pale buffy area from 'ankle 1 to body; tail 
indistinctly bicolor, buffy white below and on sides, pale brownish 
buff on top. Worn pelage: Similar to unworn pelage but brighter 
with dusky tone entirely eliminated, hairs tipped with rusty, tail 
very indistinctly bicolor. Young in first coat: General effect of 
upperparts smoke gray produced by slate gray underfur overcast 
by buffy white. Adolescents: Darker and more grayish than adults, 
otherwise similar. 

Skull. — Essentially as in P. polionotus, but larger; molar teeth 

Measurements. — Average of 10 adult topotypes: Total length, 130 
(128-153) ; tail vertebra, 52 (50-00) ; hind foot, 18.1 (17-19) ; ear 
from notch (dry). 12.4 (11.6-13.5). 

Type specimen. — No. |^f| American Museum of Natural History, 
New York. $ adult. March 3, 1889. F. M. Chapman. Skin in 
fair condition; skull with right zygoma somewhat broken but re- 
paired so that no parts are missing. 

Remarks. — The range of niveiventris as worked out by Bangs is 
very limited, including only the narrow strip of beach on the eastern 
coast of Florida where sea oats (Uniola) grow. This, however, 
does not of necessity preclude the possibility of intergradation with 
polionotus. the range of which is often interrupted, as is that of 
bairdi. which covers a wide area, but only on prairies and ivplands, 
so that many small colonies are considerably isolated. 

The color of the underparts in niveiventris, phasma, albifrons, 
and rhoadsi — white to the roots of the hairs — is unique within the 
genus with one exception. This is P. I. ammodi/tes from Monomoy 
Island, Massachusetts, which also lives on sandy beaches near salt 
water. P. m. margaritae from Lower California also shows much 


superficial resemblance to it. Such parallel development from the 
same apparent causes suggests that purely physical processes may 
have determined it. 

Specimen* examined. — Total number 188, from localities as fol- 
lows : 

Florida: Canaveral, 8; Hillsboro Inlet. Dade County, 2: Jupiter Island, 
22: Lake Worth, 3; <>ak Lodge, opposite Micco, 149 ; Palm Beach, 4. 


Peromyscus phasma Bangs, Proo. Bost. Soc. Nat. Hist.. XXVIII, pp. 199-200, 
March, 1898. 

Type locality. — Point Romo, Anastasia Island, Florida. 

Characters. — Similar in size to niveiventris, but pallid color much 
accentuated; white markings more extensive; nose and spots over the 
eyes and at base of ears pure white and very conspicuous. 

Color. — Upperparts pinkish butt' with a grayish tinge in the middle 
of the back; nose, a spot above the eye, and a spot at the base of the 
ear white; underparts pure white to the roots of the hairs, the white 
extending farther up on the sides than in niveiventris ; feet and both 
fore and hind legs pure white all around; tail white, unicolor, or 
with faint traces of dusky on the upper side; ears grayish white 
within and without. 

Skull. — As in P. p. niveiventris. 

Measurements. — Average of 10 adult topotypes: Total length 138.5; 
tail vertebrae 53.5; hind foot 18.7; ear from notch 14. 

Type specimen. — Xo. 7l7?> Museum of Comparative Zoology, Cam- 
bridge, Mass. ; formerly in collection of E. A. and O. Bangs. £ adult. 
Feb. 11, 1897. (). Bangs. Skin practically perfect; skull without 
first upper molar, otherwise perfect. 

Remark*. — -This form shows an extreme of paleness. It is thus 
quite the antithesis of polionotus. In general terms, therefore 
niveiventris is intermediate in color between phasma and polionotus. 
Although individual variation in niveiventris does not reach the nor- 
mal type of phasma, variation in that direction is not infrequent, as 
shown by certain specimens with incipient white superciliary spots 
and the white of the underparts extending to the lower margin of 
the eye. 

Specimens examined. — Total number 54, all from the type 


Peromyscus subgriseus rhoadsi Bangs, Proc. Bost. Soc. Nat. Hist., XXVII, pp. 
201-202, March, 1S98. 

Type locality.— Head of the Anclote Eiver, Hillsboro County, Fla. 
Geographic distribution. — West central Florida, in the vicinity of 
Tampa Bay. 


Characters. — Similar to P. niveiventris, but size smaller; color 
averaging slightly darker; hairs of underparts white to roots or very 
slightly slaty at bases. 

Color. — Similar in general to that of niveiventris, but averaging 
darker, thus being intermediate between niveiventris and polionotux. 
Type in slightly worn pelage (May) : Upperparts, sides, head, cheek-, 
etc., rather dark ochraceous buff (slightly deeper colored than in 
niveiventris), sparingly mixed with dusky; underparts creamy white, 
locally with traces of pale slaty at bases of hairs; ears rather darker 
than in niveiventris; feet white; tail white above and below distally, 
narrowly brownish buffy above proximally for about half its length.* 
Unworn pelage (as partially indicated by available material) : Simi- 
lar to that of niveiventris, but slightly darker and more grayish. 

Skull. — Similar to that of niveiventris and polionotus, but smaller 
than in either. 

Measurements. — Type: Total length 124.5; tail vertebrae 4G; hind 
foot 10.5. Average of 10 adults from Tarpon Springs, Fla., and 
vicinity: 120; 47; 17. 

Type specimen. — No. 0980 Museum of Comparative Zoology, Cam- 
bridge, Mass., formerly in collection of E. A. and O. Bangs. $ adult, 
old. May 23, 1895. W.S.Dickinson. Skin in fair condition. Skull 
perfect, except for a slight break in the left audital bulla; crowns of 
molars greatly worn. 

Remarks. — As suggested by Bangs, this form may range through- 
out southwestern Florida. Its relationship to polionotus is close, and 
specimens having some slaty gray at the bases of the hairs of the 
underparts are not uncommon even among those from the vicinity 
of the type locality. Except for its small size, its characters are inter- 
mediate between those of niveiventris and polionotus. Specimens 
from Citronelle, although strongly approaching polionotus, seem 
better referable to rhoadsi. 

Specimens examined. — Total number 23, from localities as follows : 

Florida: Head of Auclote River, 6; Citronelle, 2; Cootie River, 4; Tar- 
pon Springs, 11. 


Type from Whitfield, Fla. No. 1297 Carnegie Museum, rittsburg, Pa. $ adult. 
Apr. 17, 1903. W. E. Clyde Todd. 

Geographic distribution. — Coast of western Florida and Alabama. 

Characters. — Similar to P. p. rhoadsi. but white of underparts 

more extensive; end of nose and narrow stripe extending nearly to 

° Specimens having the tail entirely unieolor are to be found as in niveiven- 
tris; in the type of rhoadsi the upper and lower sides of the tail were reversed 
in preparing the specimen and the color of the natural upper side is easily 


interorbital region white or whitish: white of underparts reaching 
lower border of eye; thighs whitish with little or no extension of 
body color on inner sides. 

Color. — General color of upperparts much as in P. p. rhoadsi; 
back and sides in slightly worn pelage (April) grayish fawn; hairs 
of underparts white to roots or very slightly plumbeous at bases; end 
of nose white and thence narrowly white or whitish on median line 
to the lower forehead between the eyes; white of underparts extend- 
ing to lower border of eye; feet and legs white all around, thighs 
without extension of body color; ears broadly edged with white and 
with a few white hairs at bases; tail white all around except basal 
third or fourth, the upper side of which is pale grayish brown. 

Skull. — Similar to that of /'. [>. r/toadsi, but slightly larger; molar 
teeth slightly larger. 

Measurements. — Average of 10 adult topotypes: Total length 130 
(122-130) ; tail vertebra' 19 (11-53) ; hind foot 17.5 (17-19). 

Remarks. — So little mammal collecting has been done in the eastern 
Gulf States, except in peninsular Florida, that the discovery of this 
well-marked form in' the western or ' panhandle ' part of Florida is 
not surprising. It Avas first received from W. E. Clyde Todd, As- 
sistant Curator, Section of Vertebrate Zoolog}^, Carnegie Museum, 
who collected the type series. Later, specimens were secured on the 
coast of Alabama by A. II. Howell of the Biological Survey. 

Specimens examined. — Total number 19, from localities as follows: 

Alabama: Bon Secour, 6." 
Florida: Whitfield, 13. 


Peromyscus melanotic Allen and Chapman, Bull. Am. Mus. Nat. Hist., N. Y., 

IX, p. 203, June 16, 1897. 
Peromyscus cecilii Thomas, Ann. & Mag. Nat. Hist., Lond., Ser. 7, XI, 

pp. 486-487, May, 1903 — Santa Barbara Camp, S. sloi>e Mount Orizaba, 

Puebla, Mexico. 
Peromyscus melanotis zamelas Osgood, Proc. Biol. Soc. Wash., XVII, p. 59, 

Mar. 21, 1904 — Colonia Garcia, Chihuahua, Mexico. 

Type locality. — Las Vigas, Veracruz, Mexico. Altitude, 8,000 feet. 

Geographic distribution. — Higher slopes of the principal moun- 
tains of Mexico north of the States of Guerrero and Oaxaca. Ex- 
tending along the Cordillera of Veracruz; westward from Mount 
Popocatepetl to the Sierra Nevada de Colima, and northward into 
the Sierra Madre of Durango and Chihuahua. Transition and Cana- 
dian zones, from 7,000 feet to 12,000 feet altitude. 

° Received too late for use in connection with the distribution map (Plate I). 



[NO. 2S. 

Characters. — Size small; tail very short ; pelage usually very long 
and lax. Most similar to P. m. labecula, but slightly smaller; brain- 
case broader and more rounded ; rostrum decidedly longer and more 

Color. — Winter pelage: Sides and most of upperparts tawny 
ochraceous lightly lined with dusky; median dorsal area between 
shoulders and rump distinctly darker than rest of upperparts, but 
always mixed dusky and tawny; lower cheeks and narrow lateral 
line tawny ochraceous; a very narrow dusky orbital ring; ears 
dusky brownish with whitish edgings; ear tufts not prominent, same 

Fig. l. — Distribution of Peromyscus melanotis. 

color as surrounding parts; a very small dusky spot at base of 
whiskers; underparts pure white; hands and feet white; outer side of 
"ankles' dusky brownish; tail very sharply bicolor, sooty brownish 
above, white below. Summer pelage: Sides tawny ochraceous, 
clouded with sooty; middle of back, from shoulders to base of tail, 
nearly black, with only slight mixture of tawny; dusky markings 
more extensive than in winter pelage, otherwise similar. Young: 
Sides pale hair brown overlaying deep slate color; middle of back 
blackish slate ; underparts washed with white. 

Skull. — About the size of that of P. m. sonoriensis; characterized 
chiefly by long, slender rostrum and nasals, decidedly longer than 


in P. m. fulvus or P. m. labecula; nasals more compressed poste- 
riorly; braincase more rounded; interorbital space narrower; 
prezygomatic notch less prominent; audital bullae slightly smaller; 
teeth about as in P. m. fulvus, smaller than in labecula. 

Measurements. — Adult $, topotype: Total length, 1-18; tail verte- 
bras, 58; hind foot, 21. Average of G adults from Perote and Cofre 
de Perote, Veracruz: 155 (132-168); 64 (58-66); 20.7 (20-21.5); 
ear from notch (dry), 18 (17-19.2). Of 5 from Mount Orizaba: 
161.4 (155-172); 71.8 (64-79); 21.7 (21-23). Of 10 from Mount 
Tancitaro, Michoacan: 167 (160-175) ; 77.5 (71-81) ; 21.5 (21-22). 

Type specimen. — No. {fill American Museum of Natural History, 
New York. $ adult. April 30, 1897. F. M. Chapman. Specimen 
in good condition. Skin in " left over " winter pelage, quite pale, 
with very little black on dorsum. 

Remarks. — The small size and short tail of P. melanotis distinguish 
it from all other Mexican species except those of the maniculatus and 
leu co pus groups. From the species of both of these groups it differs 
in cranial characters, particularly in the length and slenderness of 
the rostrum. Its long full pelage and short, sharply bicolor tail 
readily distinguish it from te Minus, mesomelas, etc. It does not 
have the conspicuous ear tufts of labecula and fulvus, and its ears 
are larger and darker than in either of these. Nevertheless, speci- 
mens in certain pelages are not always distinguishable by external 
characters except size. It is found at high altitudes on most of the 
loftier mountains of central Mexico, and, though absolutely isolated 
in many such places, it shows remarkably little deviation from one 
general type. The variation is so slight that there seems to be no 
logical basis for the separation of local forms. The species shows 
considerable seasonal variation, however. In most Mexican species 
change of pelage seems to be irrespective of season. In this moun- 
tain species, however, distinct winter and summer pelages occur. 
As no specimens taken at one locality at different seasons are avail- 
able, it is difficult to be sure that there are two yearly molts in this 
species, but the present material seems to indicate two. At any rate, 
all the winter specimens are in a relatively light-colored pelage and 
all the summer ones are in a darker pelage. Moreover, spring (May) 
specimens from Cofre de Perote, Veracruz, are changing from a 
worn, light-colored pelage to a fresh dark state, while fall (October) 
specimens from Salazar, Mexico, show a worn, dark pelage, which 
is being replaced by a fresh, light-colored one. P. cecilii was based 
on specimens of P. melanotis in summer pelage. Specimens taken in 
April on the west slope of Mount Orizaba at an elevation of 9,500 
feet are in somewhat worn winter pelage, and show very little black. 
They do not differ from ordinary melanotis from numerous localities. 
There is only slight variation in cranial characters. Specimens from 


Mount Tancitaro are a trifle larger and have rather wider nasals than 
usual. Similar specimens may be found in any good series from 
elsewhere. The molar teeth are somewhat larger than usual in series 
from Ajuseo and Salazar, Mexico. The specimens representing the 
supposed form ' zamelas ' are very extensively black and are from a 
region greatly removed from the type localit}^ of melanotic, but prob- 
ably represent the extreme phase of the ordinary summer pelage. 

Specimens examined. — Total number 203, from localities in Mexico, 
as follows: 

Chihuahua: Colonia Garcia. 8; Sierra Madre near Guadalupe y Calvo, 18. 

Durango: Coyotes, 8; near El Salto, 5; near Guanacevi, 3. 

Hidalgo: Sierra de Pachuca, 3; Tulancingo, 1. 

Jalisco: Sierra Nevada de Colima (12,000 feet), 8. 

Mexico: Ajuseo, 14; southwest slope Mount Iztaccihuatl (13,500 feet), 3; 

north slope Mount Popocatepetl (11,500 feet), 12; Salazar, 28; north 

slope Yolcan Toluca, 15. 
Michoacan: Mount Tancitaro (12,000 feet), 27. 
Morelos: Huitzilac, 6. 

Puebla: West slope Mount Orizaba (0.500 feet), 7: Mount Orizaba, 15. 
Tamaulipas: Miquihuana, 1. 
Veracruz: Cofre de Perote (12,500 feet), 10; Las Vigas, 3; Perote, 1; 

Santa Barbara Camp, Mount Orizaba, 3. 
Zacatecas: Valparaiso Mountains, 4. 

Key to subspecies of Peromyscus leucopus. 

a. Habitat north of Mexico. 

b. Hairs of underparts chiefly white basally. Monomoy Island, Massachusetts. 

P. /. atnmodytes 
bb. Hairs of underparts chiefly slaty basally. 

c. Color largely tawny or ochraceous buff. Chiefly eastern and northern. 

d. Size large : hind foot 22-24 ; greatest length of skull usually more than 27 ; 
rostrum and nasals longer. Marthas Vineyard, Massachusetts. 

P. I. fusus 
dd. Size smaller ; hind foot 20-28 ; greatest length of skull usually less than 27 ; 
rostrum and nasals shorter. 
C. Color darker, usually with a well-differentiated dorsal stripe. Chiefly 
east of the 100th meridian. 

1. Color darker; size smaller. Southern P. leucopus 

2. Color paler; size larger. Northern P. I. tioveboracensis 

re. Color paler, usually with dorsal stripe only slightly developed or absent. 

Chiefly west of the 100th meridian. 

1. A slight dorsal stripe usually evident P. /. aridulus 

2. No dorsal stripe evident P. I. oehraceus 

cc. Color largely fawn or vinaceous cinnamon. Chiefly Texas, New Mexico, and 

d. Size larger ; hind foot 21-24 ; molars larger ; maxillary toothrow about 4. 

e. Color paler P. 1. tornillo 

cr. Color slightly darker P. /. arizona 

dd. Size smaller ; hind foot 20-23 ; molars smaller ; maxillary toothrow less 

than 4 P. 1. texanus 

aa. Habitat Mexico. 

b. Color chiefly pale fawn with relatively little dusky mixture. 

c. Habitat south of lat. 20° north P.l.afflnis 

cc. Habitat north of lat. 20° north. 

d. Size larger : molars heavier ; maxillary toothrow about 4. Chiefly north- 

1. Color paler =. P. 1. tornillo 

2. Color slightly darker P. I. arizonw 


dd. Size smaller ; molars weaker ; maxillary toothrow less than 4. Chiefly 

northeastern p. I. texanua 

66. Color chiefly dusky or rich dark fawn largely mixed with dusky. 

c. Color slightly paler ; adolescents not very blackish above. Peninsula of Yucatan 
and adjacent islands. 

1. Size larger; skull and teeth heavier. Cozumel Island P. I. cozumelm 

2. Size smaller. Mainland of Peninsula of Yucatan P. 1. castaneus 

cc Color slightly darker ; adolescents with blackish dorsum. Veracruz and 

Puebla p. 1. mesomelas 

(PL VI, fig. 4.) 

Musculus a leucopus Rafinesque. Am. Monthly Mag., Ill, p. 446, October, 1818. 

Mus leucopus Desmarest, Mammalogie, II, p. 307, 1822. 

Hesperomys leucopus Le Conte, Proc. Acad. Nat. Sci. Phila., p. 413, 1852. 

Hesperomys (Vesperimus) leucopus Coues, Proc. Acad. Nat. Sci. Phila., p. 178, 

Vesperimus americanus Allen, Bull. Am. Mus. Nat. Hist, N. T., Ill, p. 297, 
June 30, 1891 (part). 

Peromyscus leucopus Thomas, Ann. & Mag. Nat. Hist., ser. 6, XV, p. 192, foot- 
note, February, 1895. 

Type locality. — Western Kentucky ; assumed to be near the mouth 
of the Ohio River. . 

Geographic distribution. — Western Kentucky south to southern 
Louisiana, west to Indian Territory, and east around the southern 
end of the Allegheny Mountains to eastern Virginia. Lower Austral 

Characters. — Size medium (hind foot about 20) ; tail usually 
shorter than head and body (rarely exceeding 80) ; tail evenly clothed 
with short hairs, decidedly less hairy than in P. in. gracilis; proximal 
two-fifths of hind foot hairy; ears medium (about 14 from notch) 
and thinly haired. 

Color. — No. 132230, Mer Rouge, La., February 12, in new pelage: 
General color of upperparts Mars brown rather coarsely mixed with 
dusky ; middle of back only slightly darker than remainder of upper- 
parts; ears dusky, very narrowly margined with whitish, no white 
spots at bases; face like sides, no definite orbital ring, whiskers black- 
ish above, white below; tail dusky brownish above, white below; 
hands and feet white, upper side of forearm dusky, ' ankles ' brown- 
ish ; underparts white somewhat modified by a slaty undercolor. No. 
70984, Avery, La., March 10, pelage beginning to wear: Ground color 
of upperparts much as in No. 132230 but slightly more reddish ; dusky 
mixture stronger and dark dorsal area more definitely different from 

The generic name Musculus was at one time mentioned by Coues (Monogr. 
N. Am. Rodentia, p. 46, 1S77) as having claims for recognition instead of 
Hesperomys, then in use. It antedates Peromyscus, but since it is merely an 
emended form of Mus and was definitely stated to be such by Rafinesque, it 
has no standing. 

66268— No. 28—09 8 



[no. 28. 

sides. No. 71(507, Hickman, Ky., April 20, pelage much worn: Sides 
and head rather dark cinnamon rufous without mixture of dusky, 
but with occasional brownish hairs; middle of back darker, nearty 
russet, brownish hairs more numerous. Adolescent, No. 33978, 

Houma, La., May 14: Upperparts Prout brown heavily mixed with 

Skull. — Averaging slightly smaller than in P. 1. noveboracensis / 
decidedly smaller than in P. gossypinus; molar teeth and audita! 
bulla? smaller; zygoma less deeply notched by infraorbital foramen; 


palatine slits usually narrower at either end than in the middle, thus 
together being elongate fusiform in shape; palatine slits usually ending 
well in advance of the plane of the front of first upper molar; pre- 
maxillae somewhat swollen laterally in front of infraorbital foramina; 
interparietal moderate, about three times as long transversely as 

Measurement*. — Two specimens from Big Sandy, Tennessee: Total 
length, 180, 175; tail vertebra?, 78, 73; hind foot, 22, 20; ratio of tail 
vertebrae to total length, 0.433, 0.417. Average of 6 adults from 
Houma, La.: 166.5 (158-177) ; 77 (73-80); 20.5 (20-21); ear from 
notch (dry) 13.7 (13.4-14). One adult from Hickman, Ky. : 168; 
73; 19, 

Type specimen. — Not known to be in existence. 

Remarks. — The species Peromyscus leucopus, considered as a 
group, is naturally divisible into three subspecies in the northeast 
and several others (texanus, etc.) in the soutlmest. The three 
forms of the northeast are well characterized at the extreme points 
of their range, which may be said to represent the apices of a tri- 
angle. They range without interruption from one to the other with 
complete intergradation. If these forms could be redescribed and 
new types designated, we should take the type of one from central 
New 7 England, another from eastern Montana, and the third from 
southern Louisiana. The actual type locality of leucopus, however, is 
between the extremes, and the name must be used for one of two 
forms neither of which is well developed at this locality. With a 
rather meager representation of specimens from the type region of 
leucopus, it has seemed best to apply the name to the dark southern 
form, which is well developed in southern Louisiana and ranges 
north to western Tennessee and Kentucky, where it begins to show 
tendencies toward P. I. noveboracensis. Eafinesque does not give an 
exact locality in proposing the name leucopus, but in prefacing a 
number of descriptions, including that of Musculus leucopus, says: 

I have visited since the lower parts of the Ohio, the Wabash, Green River, 
Barrens, Prairies, and the States of Indiana, Illinois, etc., where I have added 
much to my former discoveries. 

One of the species (?) {Gerbillus megalops) named on the same 
page with Musculus leucopus, is said to be found "in the barrens of 
Kentucky."' No other mention of locality is made. Recent authors 
have in several instances considered the ' pine barrens of Kentucky ' 
as the type locality. Since, however, the original locality mentioned 
was inclusive, it seems permissible to select a definite locality from 
among those known to have been visited by Rafinesque on the trip 
mentioned above. Apparently the most southern locality visited by 
him was the mouth of the Ohio River, and as it is desirable to apply 
the name leucopus to the southern form of the group, this may be 


considered the type locality. The only specimens I have seen from 
this region are those of a small series from Hickman, Ky. These, 
while evidently somewhat intermediate, are nearer to the dark 
southern form, and therefore the name leucopus is applied to this 
form rather than to the northern one, for which the name nove- 
boracensis is available. 

The long use of the name leucopus warrants its retention, even if 
it be necessary to construe its author liberally. The applicability 
of Rafinesque's description, however, is scarcely to be doubted, 
although he describes absolutely impossible' species (?) on the 
same page. The entire description is as follows: 

7. Musculus leucopus R. (White feet mouse.) Body brownish, fallow above, 
white beneath, head fallow, ears large, blackish, tail as long as the body, pale 
brown above, gray beneath, legs and feet white. Length 5 inches. 

The difference between leucopus and noveboracensis is not suf- 
ficiently marked so that individual specimens can be invariably 
identified. Still, specimens in absolutely comparable pelages are 
usually noticeably different. The character of. leucopus consists in 
a sort of saturate or intensified color. As usual in such cases, there 
is a tendency toward the extension of the dark body color to parts 
which are white in paler forms. Thus, a tawny pectoral spot is 
found frequently in leucopus, but rarely or never occurs in novebora- 
censis. The color of the upperparts extends also to the upper side 
of the forearm in leucopus, and to a less degree or not at all in nove- 
boracensis. The pelage of leucopus is shorter and possibly harsher 
than that of its northern representative. The winter pelage is not 
so long and full, and the period is shorter during which it does not 
show marked effects of abrasion. P. leucopus intergrades with nove- 
boracensis on the north and probably with texanus on the west. 
Specimens from intermediate points have been referred, sometimes 
rather arbitrarily, to the form they appear to resemble most. A 
series from the Dismal Swamp, Virginia, is thus placed with leucopus, 
although it shows decided tendencies toward noveboracensis. Speci- 
mens from the border region between the Upper and Lower Austral 
zones are more or less intermediate. The only species of Peromyseus 
found within the range of leucopus which is at all likely to be con- 
fused with it is P. gossypinus. which may be distinguished chiefly 
by its larger size and usually by its more dusky coloration. The 
skull of leucopus is smaller and less massive than that of gossypinus. 
and the molar teeth are decidedly smaller. 

Specimens exam hied. — Total number 309, from localities as follows : 

Alabama: Greensboro, S. 

Georgia: Chickamauga Park, 2 (doubtfully referred). 

Kentucky: Hickman, 8: Mammoth Cave, 2 (not typical). 

Louisiana: Avery, 1 ; Houma, 17 ; Lafayette, 2 ; Mer Rouge, 4 ; Tallulab, 5. 

Mississippi: Washington, 2. 


North Carolina: Apex, 6; Chapanoke, 14; Currituck, 14; Raleigh, 52; 

Raleigh County, 8 ; Old Richmond, 1 ; Roanoke Rapids, 5 ; Rural 

Hall, 2. 
Oklahoma: Fort Gibson, 1; Hartshorn, 2; Orlando, 1; Red Oak, 6. 
South Carolina: Calhoun Falls, 4; Catawba, 3. 
Tennessee: Arlington, 3; Big Sandy, 10; Briceville, 1; Clarksville, 4; 

Danville, 1; Dunbar Cave, 1; Nashville, 5; Samburg, 5; Watauga 

Valley, 5. 
Virginia: Cappahosic, 4; Dismal Swamp, chiefly from Lake Drummond, 

79 ; Hampton, 9 ; Newport, 3 ; Suffolk, 4 ; Tazewell, 5. 


(PL V, fig. 9; PI. VI, figs. ,8-Sa; PI. VII, fig. 3; PI. VIII, figs. 2, 2a, 2b, 2c.) 

Mus agrarius americanus Kerr, Anirn. Kingd., p. 231, 1792; not Mus americanus 

Kerr, 1. c, p. 227. 
Mus sylvaticus 5 noveboracensis Fischer, Synopsis Mamm., p. 318, 1829. 
Gricetus myoides Gapper, Zool. Journ., V, p. 204, PI. N, 1830 — Between York 

and Lake Simcoe. Ontario. 
Arvicola emmonsi DeKay in Emmons, Rept. Quad. Mass., p. 61, 1S40 — Massa- 
Peromyscus arborcus Gloger, Hand u. Hilfsbuch Naturgesch., I, p. 95, 1841. 
Mus michiganehsis Audubon and Bachman, Journ. Acad. Nat. Sci.. Phila., 

pp. 304-306, 1S42— Erie Co., Mich. (—Ohio). 
Hesperomys campestris Le Conte, Proc. Acad. Nat. Sci. Phila., VI (1852-53), 

p. 413, 1853— New Jersey. 
Vesperimus americanus Allen, Bull. Am. Mus. Nat. Hist., N. Y., Ill, p. 2'.)T, 

June 30, 1891 (part). 
Sitomys americanus Miller, Proc. Biol. Soc. Wash., VIII, p. 55, June 20, 1893. 
Peromyscus leucopus noveboracensis Miller, Proc. Boston Soc. Nat. Hist., 

XXVIII, p. 22, April 30, 1897. 
Peromyscus leucdpus minnesotce Mearns, Proc. Biol. Soc. Wash., XIV, pp. 

154-155, August 9, 1901— Fort Snelling, Minn. 

Type locality. — New York. 

Characters. — Similar to P. leucopus, but averaging paler and 
slightly larger; pelage longer and softer; tail more thickly clothed 
with hair. 

Geographic distribution. — Upper Austral and Transition zones of 
the eastern United States and Canada. Extending from Nova Scotia 
to central Minnesota, thence south through the humid parts of east- 
ern Nebraska and Kansas and eastward to the Atlantic coast, fol- 
lowing quite closely the boundary between the Lower and Upper 
Austral zones on the south and that between the Transition and 
Qanadian on the north. 

Color. — Similar to that of P. leucopus, but lighter and brighter; 
underparts usually pure white, entirely concealing undercolor; tail 
less distinctly bicolor. No. G9902. $ adult, November 25, Ossipee. 
N. H., new winter pelage: Upperparts cinnamon rufous, lightly 
mixed with dusky lines on sides, more heavily on middle of back; 
underparts creamy white ; hands, feet, and forearms white ; ' ankles ' 


slightly brownish; ears dusky brownish with pale whitish edges; 
tail white below, dusky above. No. 126310, $ adult, April, New- 
burgh, N. Y., pelage slightly worn: Similar to No. 69902, but sides 
brighter, less mixed with dusky; dark dorsal area more contrasted 
with sides. No. 98776, $ adult, June 10, Eliot, Me., pelage much 
worn: General color of upperparts bright tawny, shading to dark 
cinnamon rufous in middle of back; sides nearly pure tawny with 
very few dusky tipped hairs and few brownish tipped ones. No. 
76386, adolescent 9 , Ossipee, N. H., Dec. 30 : Sides, face, etc., fawn 
color lightly mixed with dusky; middle of back decidedly darker. 

Skull. — Practically as in P. leucopus; averaging very slightly 

Measurements. — Average of 10 adults from Montauk Point, New 
York: Total length, 173.4 (163-188); tail vertebra-, 77.5 (73-83); 
hind foot, 21.4 (21-22) ; ratio of tail vertebrae to total length, 43.5; 
ear from notch (dry) 14.3 (13.6-14.7). Of 10 adults from Ossipee, 
N. H.: 166.4 (159-182) ; 79 (75-88) ; 21 (20-22). Of 10 adults from 
Fort Snelling, Minn.: 181.7 (175-187) ; 77.5 (72-80) ; 21.4 (20.5-22). 

Type specimen. — Not known to be extant. 

Semarks. — By restricting the name leucopus to the Lower Austral 
form, the subspecies of the northern and eastern United States which 
has usually been known as lcu<-<>j>us. will be called noveboracensis. It 
is perhaps the best known of the white- footed mice, as it ranges over 
the most thickly populated part of the United States. Within its 
range at least two other species are found — P. gracilis'^ which is 
longer tailed and duller colored, and P. bairdi, which is decidedly 
smaller and usually more dusky in color. The name c deer mouse ' 
seems to have been given it because of its supposed seasonal change of 
color, corresponding to that of the Virginia deer. Adult mice, how- 
ever, do not show such marked seasonal difference in color as the 
deer. The gray and the 'red' coats of the deer are those of winter 
and summer, but those of the mice are of the adolescent and the fully 
mature, regardless of season. The pelage of the adult is almost con- 
tinually changing, although it appears to be entirely renewed only 
once a year. The entire new pelage is acquired in late summer or 
fall, varying from June to November, usually but not always earlier 
in southern latitudes and later in northern. At first the new coat 
is rather short, particularly if the change has occurred in midsummer. 
and the color very uniform, with little or no contrast between sides 
and back. This coat gradually fills out and black or dusky hairs 
become more numerous in the mid-dorsal region, until it is somewhat 
darker than the sides. The dusky, however, is still somewhat mixed 
with tawny, and the amount of dusky varies in different individuals. 
This condition remains practically unchanged for the greater part 
of the winter. In spring (March to May.) the pelage becomes 


roughened by abrasion and the contrast between back and sides is 
heightened. The sides become brighter, more tawny, and the tips of 
the hairs in the middle of the back wear oft', exposing more or less 
of the basal color, which is deep blackish slate. As abrasion con- 
tinues the tawny hairs become deeper colored, and the dusky fades 
to cinnamon or tawny, and when the pelage is quite short new hairs 
begin to come in on the anterior parts. The pelage of the middle of 
the rump is the last to be renewed, and specimens may often be found 
in which the pelage is entirely new except a small patch of tawny 
or cinnamon rufous on the rump. In a general way it may be said 
that the new fall and winter conditions of pelage are paler and more 
yellowish, while the partially abraded conditions of spring and 
summer are brighter and more reddish. 

The name -americanus is the earliest one for this species, but being 
preoccupied can not be used. Cricetus myoides also undoubtedly 
refers to this mouse. Arvicola emmonsi and Hesperomys <-<tih ipes- 
tri.s" are from localities inhabited only by this species, so there is no 
question of the propriety of placing them in the list of synonyms. 
The reference of Mus michiganensis to this form has been discussed 
under P. m. bairdi (see p. Si ) . P. 1. minnesota does not seem to be 
sufficiently characterized to be recognized. It shows some slight 
average tendency toward /'. /. aridulus, but is much nearer to typical 
Twveboracensis. A very large series from the type region of Minne- 
sota} contains a few specimens that are rather larger than the average 
noveboracensis and slightly paler; the rest are indistinguishable from 
typical noveboracensis. This seems to indicate a slight tendency 
toward P. 1. aridulus, but since mh>iicsot(i j is so much nearer nove- 
boracensis, and since there is not room for three forms, it seems best 
to treat minnesotce as a synonym of noveboracensis. Specimens from 
Kansas, Nebraska, Iowa. etc.. are not typical, tending toward either 
leucopus or aridulus or both. A few specimens from Nova Scotia 
have lather long tails, but the material is too scanty to warrant their 

Specimens examined. — Total number 2,084, from localities as fol- 
lows : 

Arkansas: Fayetteville. 1; Hardy, 4 (aberrant). 
Connecticut: East Hartford, 24; Liberty Hill, 12. 
District of Columbia: Vicinity of Washington, 155.' 
Illinois: Fox Lake, 1: Henderson County, 30; Parkersburg, 8; Warsaw, 
3; West Northfield, 3. 

"The type of If. campestris is preserved in the T T . S. National Museum ( N<>. 
4726), but is in such poor condition as to bo little more than generically deter- 
minable. It has no skull, and the distorted skin appears t<> have been pre- 
served originally in alcohol. 

6 Including some localities in Virginia ami Maryland. 


Indiana: Bascom, 4; Du Bois County, 1; Denver, 6; Hebron, 4; La- 
porte, 5; Mitchell, 1; Mount Ayr, 2; New Harmony, 2 (position 

Iowa: Burlington, 57; Council Bluffs, 5; Knoxville, 10; Redfield, 1. 

Kansas: Fort Leavenworth, 6; Fort Riley, 2; Lawrence, 24; Manhattan, 
5; Neosho Falls, 2; Onaga, 7. 

Kentucky: Eubank, 19; Lexington, 13 (aberrant). 

Maine: Eliot, 3; Oakland, 1; Small Point, 2. 

Maryland: Grantsville, 3; Hyattsville, 2; Laurel, 9; Plummer Island, 2; 
Rawlings, 2; Rockville, 1; Swanton, 3. 

Massachusetts: Barnstable Neck, 17 ; a Bedford, 11; Belmont, 2; Con- 
cord, 1 ; Lexington, 6 ; Maiden, 2 ; Middleboro, 14 ; Monomoy Island, 
81; Muskeget Island, 17; Nantucket Island, 13; Seehonk, 4; Shef- 
field, 4 ; South Hanson, 4 ; Wareham, 64 ; West Dedham, 5 ; Wil- 
mington, 27. 

Michigan: Ann Arbor, 10; Au Sable River, Oscoda County, 2; 6 Gray- 
ling, 1 ; 6 Manchester, 2; Spring Lake, l. & 

Minnesota: Elk River, 21 ; Farmington, 1 ; Fort Snelling, 88 ; Hinckley, 1 ; 
Minneapolis, 9. 

Missouri: Bismarck, 3; Hunter, 10; Kimswick, 1; Marble Cave, 2; Pied- 
mont, 1; Stotesbury, 16; Williamsville, 2. 

Nebraska: Havelock, l; c London, 1; Neligh, 1; South Auburn, 4; Verdi- 
gris, 2. 

New Hampshire: Antrim, 5; Ossipee, 31; Summit, Mount Washington, 
2 (introduced?) ; Webster, 11. 

New Jersey: Alpine, Bergen County, 11; Bridgeton, 22; Cape May, 1; 
Chairville Bog, Burlington County, 1; Collingwood, Camden County, 
12 ; Culver Lake, Sussex County, 24 ; Delaware Gap, 6 ; Fairview, 8 ; 
Fort Lee, 1 ; Granton, 10 ; Greenwood Lake, 28 ; Hackensack Marsh, 
1; Haddonfield, 48; Lake Hopatcong, 3; Long Lake, Sussex County, 
11 ; Mauricetown, 1 ; Mays Landing, 20 ; Nordhoff, 10 ; Pleasant Val- 
ley, 7; Port Norris, 3; Sandy Hook, 5; Sea Girt, 3; Tuckahoe, 23; 
Tuckerton, 42; Walkill Bottoms, Sussex County, 9. 

New York: Catskill Mountains, 21; Cornwall, 2; Croton Falls, 1; Eliza- 
bethtown, 7 ; Garrison, 1 ; Hastings, 40 ; Highland, 2 ; Highland Falls, 
23; Jamaica, Long Island, 8; Kiskatom, 6; Lake George, 38; Lake 
Grove, Long Island, 3; Lawyersville, 8; Locust Grove, 5; Miller 
Place, Long Island, 8 ; Montauk Point, 27 ; Newburgh, 2 ; New 
Rochelle, 1 ; Nyack, 40 ; Ossining, 2 ; Owego, 5 ; Peterboro, 8 ; Plum 
Island, 1 ; Schernerus, 1 ; Shelter Island, 2 ; Stamford, 8 ; Syracuse, 3. 

North Carolina: Magnetic City, 1; Weaverville, 42. 

Nova Scotia: Digby, 3; Newport, 3. 

Ohio: Garrettsville, 5; Hicksville, 9; Madisonville, 1; Ravenna, 6; San- 
dusky, 2. 

Ontario: Credit, 8; Lome Park, 20; Toronto, 2; Woodham, 1. 

Pennsylvania: Aldan, Delaware County, 1; Barren Ridge, 2; Bushkill 
Creek, Monroe County, 9 ; Clifton, Delaware County, 1 ; Cooks 
Mills, 32; Drury Run, 6; Erie, 2; Germantown, 7; Hopewell, Bed- 
ford County, 8 ; Jenkintown, 1 ; Keating, Clinton County, 4 ; Kings, 
Cambria County, 13; Lehigh Gap, 4; Manoa, 7; Marple, 4; Markle- 
ton, 1; Mount Union, 18; North Mountain, 1; Philadelphia (Penny- 

Including some specimens approaching ammodytes. 
6 Collection of University of Michigan. 
c Carnegie Museum. 


pack Creek), 1; Porter Lake, Pike County, 6; Renovo, 3; Round 
Island, 10; Thorndale, 5: Tinicum, Delaware County, 16; Tuscarora, 
Juniata County, 2; Tyrone, 14; Valley Forge, 2; YVaynesburg, 3; 
Westtown, 1 ; Wynnewood, 1. 

Rhode Island: Block Island, 12; Cnepachet, 10; Conanicut Island, 5; 
Fort Adams, 17 : Lake Worden, 101 ; Aliddletown, 1 ; Newport, 6. 

Vermont: Burlington, 2; Hartland, 12; Rutland, 4. 

Virginia: Peaks of Otter, 1. 

West Virginia: Franklin, 4; White Sulphur Springs, 67. 

Wisconsin: Camp Douglas, 16; Delavan, 7; Milton, 2. 


Peromyscus leucopus ammodytes Bangs, Proc. New Eng. Zool. Club, IV, pp. 
14-15, Feb. 28, 1905. 

. Type locality. — Monomoy Island, off coast of Massachusetts. 

Characters. — Upperparts decidedly paler than in P. I. noveboracen- 
sis; imderparts pure white to roots of hairs; otherwise similar to 

Color. — December specimens: General color of sides pale fawn; 
middle of back darker, but somewhat mixed with fawn; median 
underparts pure creamy white to roots of hairs, this sometimes ex- 
tending laterally almost to lower sides; hands and feet white; tail 
pale browmish fawn above, white below T ; ears pale brownish dusky 
thinly clothed with whitish hairs on the inside and on the marginal 
part of the outside. 

Skull. — Practically as in P. I. noveboracensis. 

Measurements. — Average of 10 adult topotypes: Total length 173 
(161-190) ; tail vertebrae 79 (71-88) ; hind foot 20 (19.5-21) ; ratio 
of tail vertebrae to total length 45.6. 

Type specimen. — In the Museum of Comparative Zoology, Cam- 
bridge, Mass. Formerly No. 828 Collection of E. A. and O. Bangs. 
$ adult. Dec. 28, 1893. O. Bangs and G. S. Miller, jr. Specimen 
nearly perfect. 

Remarks. — Monomoy Island is a low, sandy island off the south- 
east coast of the Cape Cod Peninsula. It is periodically connected 
with the mainland by a long, narrow stretch of sand. Notwithstand- 
ing this, however, the island mice differ more markedly from those 
of the mainland than do those of any of the other islands in the 
vicinity, which are permanently cut off from the mainland. Typ- 
ical noveboracensis also occurs on the island, and various intermediate 
stages between it and ammodytes are found. A slight tendency to 
albinism is noticeable in several specimens. Specimens with nearly 
white underparts are also found on the mainland at Barnstable Neck. 
Bangs (supra cit.), in writing of this very interesting mouse, says: 

While pale grayish specimens, with pure white bellies, greatly predominate 
on Monomoy Island, there is still a wide range of variation in color, and a few 
individuals caught with the others are not distinguishable in any way from 


mainland specimens, and between those and the palest examples every degree 
of intermediate occurs. The reason for this, I think, is very simple. Monomoy, 
though often in the course of its history an island, has been at other time? 
joined to the mainland by a long beach. At such times skunks, cottontail 
rabbits, and foxes have worked their way to the island, and have established 
themselves there for at leasl a time. The deer mouse from the, mainland 
probably has come in the same way. and from time to time has infused into 
the island form the very characters it was struggling to eliminate. 

Specimens examined. — Total number 25", all from the type locality. 


Peromyscus leucopus fusus Bangs, Proc. New Eng. Zool. Club, IV, \>. 13, Feb. 
28, 1905. 

Type locality. — West Tisbury, island of Marthas Vineyard, off 
south coast of Massachusetts. 

Geographer distribution. — Island of Marthas Vineyard, Massa- 

Characters. — Similar in general to P. I. noneboracensis, but some- 
what larger; skull with slightly elongated rostrum. 

Color. — As in P. I. noveboracensis. 

Skull. — Larger and heavier than in noveboracensisj nasal and 
rostral region somewhat more elongated ; audital bulla? relatively 
rather small. 

Measurements. — Average of adult topotypes: Total length, 194.4 
(190-203) ; tail vertebra?, 90.T (85-96) ; hind foot, 22.4 (21.5-23.5) ; 
ratio of tail vertebra? to total length. 40. G. 

Type specimen. — No. 9737 Museum of Comparative Zoology, 
Cambridge, Mass. ; formerly same number, collection of E. A. and 
O. Bangs. $ adult. June 17, 1899. O. Bangs. Specimen prac- 
tically perfect. 

Remarks. — The mice from Muskeget, Nantucket, Block Island, 
and other small islands off the southern coast of New England are 
somewhat more robust than typical noveboracensis, but none of them 
seem sufficiently characterized for recognition except those from 
Marthas Vineyard. These, however, are so decidedly larger than 
noveboracensis and their skulls so easily distinguishable by size and 
other slight peculiarities that they are well deserving of separation. 

Specimens era mined. — Total number 13. all from the type locality. 


Type from Fort Custer. Mont. No. 7r»T04 T". S. National Museum. Biological 
Survey Collection. Adult 9. Nov. 12. 1895. J. A. Loring. 

Geographic distribution. — Upper Sonoran zone of eastern Montana 
and Wyoming and the adjoining western parts of South Dakota and 
Nebraska: probably south to Oklahoma and west to eastern Colorado. 

"Of these, IS are quite typical and 12 are evidently intermediate. 


Characters. — Similar to P. I. noveboracensis, but larger ami paler; 
somewhat similar to P. m. nebrascemis, but larger, with a longer tail ; 
skull with wider brainease, larger audita! bulla 1 , and larger molar 

Color. — Similar to that of P. I. noveboracensis, but decidedly paler; 
dark dorsal area much reduced; ears pale. Type : Upperparts ochra- 
ceous buff very lightly mixed with dusky; middle of back somewhat 
darker than sides, but not sharply contrasted; head and face nearly 
like sides; underparts creamy white. 

Skull. — Similar to that of P. I. noveboracensis. but larger and 
heavier; brainease usually wider; somewhat similar to that of P. m. 
nebrascensis, but brainease larger and wider; nasals broader; rostrum 
more depressed; premaxillae less swollen laterally; outer edges of 
palatine slits less nearly parallel; molar teeth larger; audital bullae 

Measurements. — Type: Total length, 177; tail vertebrae, 73; hind 
foot, 22; ear from notch (dry), 14.5. Average of 4 topotypes: 169 
(160-177); 69 (63-73); 22 (21-23); 14.1 (13.6-15.5). Average of 
5 adults from Valentine, Nebr. : 184 (170-196); 86 (75-90); 22.2 
(21-23). Adult female from Buffalo Gap, S. Dak.: 205; 93; 22. 

Remarks. — The range of this form is probably more extensive than 
is indicated by the specimens now at hand. It is probable that it ex- 
tends down through western Kansas and meets that of P. I. texanus. 
Although its range is in the arid subdivision of the Upper Austral 
zone, it appears that it lives chiefly in the relatively humid parts of 
this region, that is, along the watercourses and in the slightly wooded 
places. The more open and relatively more arid parts of the region 
are inhabited by P. m. nebrascensis, which is often very nearly the 
same color as P. I. aridulus. P. m. nebrascensis is specifically dis- 
tinct, however, and may be distinguished from aridulus not only by a 
combination of cranial characters, but also by its smaller size and 
shorter tail, and by the presence, in most cases, of definite white spots 
in front of the ears. 

Specimens from eastern Nebraska and Kansas are apparently inter- 
mediate between noveborascensis and aridulus, having the darker color 
of fwveboracensis and the larger size of aridulus. 

The reference of specimens from Oklahoma to this form is rather 
unsatisfactory. There seems to be no other disposition of them, how- 
ever, so far as can be judged by present material. The localities from 
which these specimens came are chiefly near the boundary between 
the humid and arid regions, and they are also near the line between 
the Upper and Lower Sonoran zones. If we suppose that leucopus, 
texanus, etc., have continuous distribution with gradual intergrada- 
tion (and no doubt this is the case), we should expect to find speci- 


mens in central Oklahoma intermediate in character between aridulus 
and texanus on the one hand and between leucopus and texanus on the 
other. Actual specimens meet all the requirements of the hypothetical 
case, not being exactly like any of the three species mentioned when 
compared with specimens from the respective type localities. They 
are more ochraceous than texanus, paler than leucopus, and slightly 
darker and more vinaceous than aridulus, and still not the same as 
iioreboracensis, although some are quite similar to intermediates be- 
tween aridulus and novel) or acensis from eastern Kansas and Nebraska. 
If not referred to aridulus, they should be placed with texanus. 

Specimens examined. — Total number 148, from localities as fol- 

Minnesota: Browns Valley, 2 (approaching noveboracensis) . 

Montana: Crow Agency, 2; Custer Station, 2; Fort Custer, 11; Little 
Bighorn River, 1. 

Nebraska: Cody (10 miles south), 4; A^alentine, 9; head of Warbonnet 
Creek, l.« 

South Dakota: Buffalo Gap, 1; Custer, 1; Spring Creek, 9; Squaw 
Creek, 6. 

Oklahoma: Alva, 11; Apache, 1; Chattanooga, 3; Kiowa Agency (11 
miles southeast of Fort Cobb), 1; Lawton, 1; 17 miles southeast of 
Fort Cobb, 1; Noble, 21; White Horse Spring, 16; Wichita Moun- 
tains (chiefly in vicinity of Mount Scott), 44. 


Type from Winslow, Ariz. No. 53301 U. S. National Museum, Biological Sur- 
vey Collection. $ adult. Apr. 30, 1893. C. P. Streator. 

Characters. — Similar to P. I. tornillo and P. I. arizonce, but color 
ochraceous buff instead of fawn ; no obvious dorsal stripe. 

Color. — Ground color of upperparts bright ochraceous buff with- 
out suggestion of fawn ; entire upperparts lightly lined with dusky, 
slightly more thickly on middle of back than on sides, but not form- 
ing a definite dorsal stripe ; ears edged with creamy white ; no white 
spots at base of ears ; underparts white .tinged with ochraceous buff ; 
tail dusky brownish above, buffy white below ; feet and hands buffy 
white; wrists marked with ochraceous buff. 

Skull. — Practically as in P. I. tornillo; infraorbital part of zygoma 
very heavy. 

Measurements. — Type and one topotype: Total length, 180, 173; 
tail vertebras, 82, 82 ; hind foot, 22.5, 22.5. 

Remarks. — This form is most closely similar in color to P. I. aridu- 
lus, differing in being slightly more ochraceous and in almost totally 
lacking any dark dorsal stripe. Its color is very much the same as 
that of highly colored examples of P. m. nebrascensis, from which it 
is distinguished by the numerous external and cranial characters of 

Carnegie Museum. 


the leucopus group. Its real relationship is probably with tomillo 
and arizonce rather than aridulus. Specimens from Fort Verde, 
Ariz., are variable, some closely resembling arizonce and others being 
deep ochraceous, somewhat darker than the type of ochraceus. 
Specimens examined. — Total number 9, from localities as follows: 

Arizona: Baker Butte, Mogollon Mountains, 1; Fort Verde, 6; Wins- 
low, 2. 

(PI. Ill, fig. 1.) 

Peromyscus tomillo Mearns, Proc. U. S. Nat. Mus. XVIII, pp. 445-446, Mar. 25, 

Peromyscus texanus flaccidus Allen, Bull. Am. Mus. Nat. Hist., N. Y., XIX, 

pp. 599-600, Nov. 14, 1903— Rio Sestin, Durango, Mexico. 

Type locality. — Rio Grande, 6 miles above El Paso, Tex. 

Geographic distribution. — Upper Sonoran zone and part of the 
Lower Sonoran of western Texas and eastern New Mexico ; north to 
southeastern Colorado and south to northern Durango; northeast 
to western Oklahoma. 

Characters. — Size, proportions, and cranial characters about as 
in P. I. aridulus; color very much paler, more fawn ; back only slightly 
or not at all darker than sides; no white at base of ear. Similar to 
P. I. arizonm but averaging paler. Similar to P. I. texanus but aver- 
aging larger and slightly paler; skull larger and more angular; 
molar teeth heavier. 

Color.— No. 58379, ? adult, February 3, El Paso, Tex., in full 
winter pelage : Ground color of upperparts fawn color uniformly 
mixed with fine dusky lines; head and face about like back and 
sides; no white spot at base of ear; underparts pure creamy white; 
hands, feet, and arms white ; ' ankles ' white, except a faint brownish 
spot on outer side; ears dusky, rather broadly edged with whitish; 
tail indistinctly bicolor, pale brownish above, white below. Worn 
pelage: Brighter and more rufescent than winter pelage; general 
color ranging from pale fawn to vinaceous cinnamon. 

Skull. — Practically the same as that of P. I. aridulus; averaging 
larger and more angular than in P. leucopus or P. I. texanus; molar 
leeth broader and heavier than in texanus. Compared with that of 
P. m. bland us the skull of tomillo is larger; braincase relatively 
wider and lower: nasals narrower, more convex, and more com- 
pressed posteriorly; premaxilla? more swollen laterally; palatine 
slits relatively shorter and with more lateral convexity; mandibles 
relatively shorter and thicker ; lateral protuberance at base of lower 
incisor more prominent; angle below mandibular condyle shallower 
and more obtuse. 


Measurements. — Average of 10 adults from the vicinity of El Paso, 
Tex.: Total length, 182 (171-202) ; tail vertebra', 82.6 (75-97) ; hind 
foot, 2^.5 (21-24) ; ratio of length of tail vertebra 1 to total length, 
45.4; ear from notch (dry), 14.5 (13.9-15.3). 

Type specinien-. — No. fHff U. S. National Museum. Adult S . 
Feb. 18, 1893. E. A. Mearns and F. X. Holzner. Specimen in good 

Remarks. — This subspecies occupies a considerable range in west- 
ern Texas, northeastern Mexico, and nearly all of New Mexico, 
maintaining its characters with great constancy throughout. It inter- 
grades on the west with P. 1. arizonce and on the southeast with P. I. 
texanus. Its relationship to leucopus is shown by specimens from 
central Oklahoma, which are evidently intermediate in color, and 
which have been referred tentatively to a rhinitis. Specimens from 
the "Panhandle" of Texas and from northeastern New Mexico 
(Clayton), while distinctly referable to tornUlo, may be considered 
slightly intermediate between tornUlo and aridulus; two immature 
examples from Canyon City, Colo., also approach aridulus. 

The only s3monym is P. flaccidus from northwestern Durango de- 
scribed by Allen who did not consider its relationship to tornUlo, 
but compared it only with arizonce, mentioning the characters which 
distinguish tornUlo and arizonce. 

Specimens examined. — Total number 219, from localities as fol- 

Chihuahua: Casas Grandes, 7; Chihuahua, 13; near Fort Bliss, Tex., 1; 

Juarez, 15. 
Colorado: Canyon City, 2; Gaume Ranch, Baca County, 1 ; a Lamar, 1;° 

Mouou, 1.° 
Durango: Rancho Santuario, 4; Rio Sestin, 29; Rio del Bocas, 3; Ro- 

sario, 4 ; San Gabriel, 4. 
New Mexico: Cabra Spring, 1; Chamberino, 1; Clapham, 7; Clayton, 5 

Corona, 1 ; Eddy, 1 ; Fort Sumner, 1 ; Jarilla, 1 ; Laguna, 1 ; La 

Mesa, 8; Manzano Mountains, .4 ; Mesa Jumanes, 2; Mesilla, 3 

Organ Mountains. 6; Rio Puerco, 7; near Roswell, 1; San Andres 

Mountains, 3 ; Sandia Mountains, 5 ; Santa Fe, 1 ; Santa Rosa, 1 

Tularosa, 10. 
Texas: Altuda, 2; Canadian, 3; near El Paso, 22; Fort Hancock, 1 

Franklin Mountains, 7; Lipscomb, 11; Miami, 3; Mobeetie, 2; Pai- 

sano, 1 ; Sierra Blanea, 10. 
"United States and Mexican Boundary: 100 m. west of El Paso, 2. 


Sitomys americanus arizonce Allen, Bull. Am. Mus. Nat. Hist., N, Y., VI, p. 321, 

November 7, 1894. 
Peroiinjscitx texanus arizonae Miller and Rebu, Proc. Boston Soc. Nat. Hist., 

XXX, p. 84, December, 1901. 

Type locality. — Fairbank, Cochise County, Ariz. 
a Collection of E. R. Warren. 


Geographic distribution. — Southeastern Arizona and adjacent 
parts of Mexico and New Mexico. 

Characters. — Similar to P. I. tomitto,but averaging slightly darker. 

Color. — As in texanus, but usually slightly darker and with a 
greater amount of dusky admixture: 

Skull. — Practically as in P. 1. tomillo. 

Measurements. — Average of 5 adults from Santa Cruz, Sonora, 
Mexico: Total length, 186 (178-198); tail vertebrae, 82.6 (78-85); 
hind foot, 22. 6 v 22-24). Two adults from San Pedro River, Arizona : 
B02; 94; 23.5—189; 87; 22.3. 

Type specimen. — No. f-fjf American Museum of Natural History. 
Adolescent $ . March 13, 1894. W. W. Price and B. C. Condit, 
Specimen in good condition. 

Remarks. — Many specimens of arizonce and tomillo arc absolutely 
indistinguishable. Large series, however, appear somewhat different 
when viewed as a whole. Some specimens of arizonce are darker than 
any of tomillo, and conversely some tomillo are paler than any 
arizonce. Darker color, then, may fairly be called an 'average char- 
acter ' of arizonae. It may be distinguished from sonoriensis, with 
which it is often found, by its larger size, longer and less distinctly 
bicolor tail, by the absence of prominent white spots in front of the 
ears and by the same cranial characters which distinguish tomillo 
from blandus. 

Specimens examined. — Total number 103, from localities as fol- 
lows : 

Arizona: Calabasas, 1: Fairbank, ."SI : Fort Lowell, 1; San Pedro River 
at Mexican boundary, 0; Tucson, 6: Turkey Tanks, 1. 

New Mexico: Deining, 4: Gila, (i: Glenwood, 1: Bedrock, 1. 

Sonora: San Bernardino Kancb, 4: Santa Cruz. 26; Santa Cruz River, S; 
Tubae, ."» : Mission of Tumacaeori, near Tubac, 1. 

(PI. 111. fig. 12.) 

Hesperomys tcxana Woodhouse, Proc. Acad. Nat. Sci. Phila.. VI (1852-3), p. 

242, 1853. 
Vesperimus mearnsii Allen, Bull. Am. Mns. Nat. Hist, N. Y., Ill, pp. 300-302, 

June, 1891. — Brownsville, Tex. 
Peremyscus canus Mearns, Proc. U. S. Nat. Mns.. XVIII, p. 44o. March 2.".. L896. 

Fort Clark, Tex. 
Peromyscus tenants Mearns, Bull. U. S. Nat. Mns. No. r><>, pp. 404-406, L907. 

Type locality. — Originally stated (probably erroneously) as the 
" Rio Grande, near El Paso," Texas. Assumed to be the vicinity of 
Mason, Mason County, Tex. (See Remarks p. 121) ). 

Geographic distribution. — Southern Texas and eastern Mexico, 
chiefly in the States of Tamaulipas and Nuevo Leon: extending west 
(o the vicinity of the mouth of the Pecos River, north to about lati 


tude 33° north, east to west side of Galveston Bay, and south to 
State of San Luis Potosi. Lower Sonoran zone. 

Characters. — Similar to P. I. tornillo, but slightly smaller and 
darker; pelage usually shorter and more subject to abrasion; tail 
more scantily haired ; skull smaller ; molar teeth smaller. 

Volor.—No. 58580 from Brownsville, Tex. $ adult, Feb. 19. 
unworn pelage: Similar in general to P. I. tornillo, but ground color 
slightly deeper darker fawn, and mixture of dusky more copious; 
ears darker; tail slightly darker above. No. 30856, August 31, worn 
pelage : Upperparts pale fawn lightly mixed with cinnamon brown. 

Skull. — Similar to that of P. I. tornillo, but averaging decidedly 
smaller; molar teeth particularly small and narrow. 

Measurements. — Average of 10 adults from Brownsville, Tex. : 
Total length, 180 (170-190); tail vertebra?, 84.8 (81-95); hind foot, 
20; ear from notch (dry). 14.8 (14.1-15.6). -Average of 10 adults 
from Fort Clark, Tex. : Total length, 178 (160-195) ; tail vertebra?, 77 
(68-91) ; hind foot, 21.5 (20.5-22.8). 

Type specimen. — No type was designated by the original describer, 
but two of his specimens, supposed to have been the basis of the name, 
are still in the U. S. National Museum, No. VsW? a skin in alcohol, 
and No. VtW •> a dry skin. The first of these was examined by 
Baird and enumerated in his list of specimens (Mamm. N. Am., p. 
464, 1857). Later, Coues gives Hesperomys texana in synonymy 
under //. leucopus (Mon. N. Am. Rodentia, p. 51, 1877), and in 
parenthesis after the reference says: "(El Paso, Tex.; type, No. 
2559, Mus. Smiths.)" The same specimen was again mentioned by 
Mearns (Proc. U. S. Nat. Mus., XVIII, p. 446, footnote, Mar., 1896), 
who says: "Two of Doctor Woodhouse's specimens are still in the 
U. S. National Museum. One of these, the type, is alcoholic, and 
the other a skin." These references doubtless account for the fact 
that No. VAV , the alcoholic, now bears a red type label, while the 
other existing specimen, No. VtVs 5 j does n °t- Besides the recent red 
type label, this specimen bears four others— a metal tag with the 
number 2559; a paper label, possibly the original collector's, with 
only the faintest indication of writing; another with the printed 
legend: "Monograph of American Muridae. Dr. Elliot Coues, 
U. S. A.," and under it " Type of," followed by the written words 
a Hesp. texanus TToodh. West. Texas. S. W. Woodhouse." On 'the 
back of this label we find u =leucopus." Still another label, com- 
paratively fresh and in an unknown hand, repeats the ordinary data 
and gives a new name, from which it is to be inferred that someone 
considered naming the specimen in honor of Doctor Woodhouse. 
This specimen then is practically the type, although it might be 
argued that No. VtW" i s a cotype of equal importance. Fortunately, 
the two specimens appear to be conspecific, and the choice between 


them is of no importance. The skin of No. VoV i s evidently so 
much shrunken that none of its dimensions can be relied upon. Its 
original color also has been altered beyond recognition. At present it 
is dark cinnamon above and dark dirty clay color below. The skull 
consists of seven separate fragments. The largest of these contains 
the nasals, part of the premaxillse, and both upper incisors. Both 
mandibles are present, and only slightly broken, all the teeth being 
intact. Three small bits of the maxillaries hold five of the upper 
molars. The braincase, bulhe, palate, etc., are entirely absent. The 
skin of No. VtW nas been taken from alcohol and remodeled and 
dried. In color it is slightly lighter below and more reddish brown 
above than the other specimen, but it plainly shows the effect of a 
long immersion in alcohol. Its skull is slightly more complete, 
although very much shattered. The mandibles are perfect, and both 
upper and lower teeth are all present. It comprises 19 distinct 

Remarks. — Waterhouse, in the original description of Hesperomys 
texcma, says, " Habitat. — Western Texas," and in the same signature, 
under " Observations ?1 : 

I procured this little animal on the Rio Grande near El Paso, while attached 
to the party under the command of Capt. L. Sitgreaves, U. S. Topographical 
Engineers, on our way to explore the Zuni and Colorado rivers. 

In the introduction to his complete report, he says: 

The party left San Antonio on the 7th of May passing over the road laid 
out under the direction of Bvt. Lieut. Col. J. E. Johnston, U. S. Topographical 
Engineers, in the year 1849, from San Antonio to El Paso, along which I made 
collections of considerable interest in the different departments of natural 

The route laid out by Lieutenant-Colonel Johnston we find was as 
follows: 6 

From San Antonio northwest to the San Saba River, via Fredericksburg, 
then westward to its source, from which he passed over to the Pecos. at Live 
Oak Creek. He then proceeded to the Lirupia River, and made his way to the 
Rio Grande by the road which strikes it about latitude 30° 38', thence he 
traveled to El Paso. 

This exact definition of the route is of considerable importance in 
determining Woodhouse's material. 

Among several forms of Peromyscus found in western Texas are 
three having relatively short tails, two of them belonging with the 
leucopus series and the third an eastern relative of sonoriensis. By 
the original description alone it would be extremely difficult to deter- 
mine to which the name was applied, but fortunately the existence of 

° Sitgreave's Exped. Zuni and Colo. Rivers, p. 33, 1853. 
b Pac. R. R. Reports, XI, p. 60, 1855. 

66268— No. 28—09 9 


specimens supposed to be cotypes renders possible a fairly satisfac- 
tory conclusion. Although in a poor state of preservation, these 
specimens are identifiable by means of numerous slight but convincing 
cranial characters with the forms (mearnsi and tornillo of authors) 
related to /< mcopus rather than with the one belonging to the 
maniculatus group (P. m. bland us). The most important of these 
characters are found in the rostrum and the mandible. In Xo. *■£-$%%*- 
the rostral part of the skull is fairly well preserved and extremely 
characteristic, having the narrow nasals and laterally swollen pre- 
maxilhe never found inP. ///. blandus, hut usually present in the forms 
represented by the names mearnsi and tornillo; the mandibles are 
relatively short and broad, unlike the slender ones of blandus, but ex- 
actly matching in proportions those of the two other forms. These 
characters alone are amply sufficient to eliminate blandus from the 
possibilities, and it therefore remains to decide to which of the other 
two the name shall be applied. The color and measurements of the 
cotypes are of almost no value on account of the immaturity of the 
specimens and the length of time they have remained in alcohol. 
Also, Woodhouse's original description and measurements were evi- 
dently taken from the alcoholics and not from the fresh specimens. 
so these otter little or no assistance, at least none in determining 
between two forms which have all general characters in common. 

One of the two forms under consideration (tornillo) occurs on 
the ''Rio Grande near El Paso." while the other occurs south and 
east of the Pecos River. The chief distinguishing character is the 
size of the molar teeth, which are larger and broader in tornillo. The 
cotypes have small, narrow teeth, exactly like those of the southern 
form and decidedly different from thoM> of the majority of speci- 
mens of tornillo. There is some variation in the size of the teeth in 
both forms, and it was at first thought that the cotypes were excep- 
tionally small individuals of the northern form, but careful search 
and comparison among a considerable series from the " Rio Grande 
near El Paso" fails to reveal a single specimen of any age with teeth 
so small and narrow as those of the cotypes. while they may be 
matched with ease by specimens from any part of the range of the 
southern form. Therefore, there seems to be no alternative but to 
apply the name to the form with which the cotypes agree and conse- 
quently to assume that Woodhouse was mistaken as to the locality 
from which they came. Considering the known laxity in such mat- 
ters on the early expeditions, it is not difficult to believe that a slight 
error in labeling was made. The view is somewhat strengthened by 
the fact that only a few days before he reached the " Rio Grande 
near El Paso " Woodhouse passed through country (San Antonio to 
San Saba River) in which we now find specimens matching his co- 


types. For example, specimens from Mason, Tex. (practically Fort 
McKavett), agree with them and the locality is on the route, so if a 
new type locality is necessary, this may be chosen. 

The average difference between P. I. texanus and P. I. tornillo is 
fairly marked, but certain individuals may be found that are indis- 
tinguishable. As a rule, however, the small size of the teeth in tex- 
anus serves to distinguish it. Specimens from the vicinity of the 
mouth of the Pecos River are intermediate between texanus and 
tornillo, but the majority are nearer texanus, having small teeth and 
averaging darker than tornillo. Among specimens of this class are 
those from Fort Clark which have been called ' canus? On the south 
intergradation with P. I. mesomelas is indicated by specimens from 
Rio Verde and Valles, San Luis Potosi, Mexico. These also, however, 
are nearer texanus. Certain specimens in full winter pelage are 
somewhat more grayish than others, possibly representing a slight 
color phase. In general the pelage differences are more marked than 
in tornillo, and summer specimens are usually very short-haired. The 
gap between the easternmost localities for texanus (vicinity of Galves- 
ton Bay) and the most southwestern localities for leucopus (southern 
Louisiana) is not very wide, and intermediate specimens are to be 
expected from this region. The material from the eastern part of the 
range is rather unsatisfactory, but the best adults are referable to 
texanus, although some tendencies toward leucopus arc exhibited. 
Three specimens from north central Texas (Decatur, Benbrook, and 
Gainesville) are practically indistinguishable from typical texanus. 
Another from Henrietta in the same general region apparently is 
intermediate between texanus and f<>rnilh>. 

Specimens examined. — Total number 572, from localities as follows : 

Coahuila: Sabinas, 3. 

Nuevo Leon: Cerro de la Silla, 4; 15 leagues south of China, 1; Lam- 
pazos, 2; Linares, 4; Monteruorelos, 6; Monterey, 28; Rodriguez, 
2; Santa Catarina, 2. 

San Luis Potosi: Rio Verde, 15.; Valles, 5. 

Tamaulipas: Alta Mira, 15; near Bagdad, 2; Camargo, 24; Hidalgo, 
11; Jaumave, 3; Matainoras, 23; Mier, 1; Nuevo Laredo, 5; Soto la 
Marina, 11 ; Tainpieo, 1 ; Victoria, 38. 

Texas: Arcadia, 1; Austin Bayou, near Alvin, 2; Bee County, 1; Bee- 
ville, 1: Benbrook, 1: Blocker Ranch, 1: Brownsville, 82: East 
Caranchua Creek, 1 ; Comstock, 4 ; Concho County, 3 ; Corpus Christi, 
1; Decatur. 1; Del Rio, 9; Deming Station, 3; Dickinson Bayou, 2; 
Eagle Pass, 7 ; El Blanco, 1 ; Elliotts, 1 ; Fort Clark, 69 ; Fort Lan- 
caster, 5 (aberrant) ; Gainesville, 3; Henrietta, 1; Juno, 1; Laugtry, 
2 ; Laredo, 2 ; 35 miles northwest of Laredo, 1 ; Lomita Ranch, 1 ; 
Mason, 7; Matagorda, 5; Nueces Bay, 7; Oconnorport, 1; Presidio, 
County, 4; Rio Grande City, 1; Rockport, 40; Rock Springs, 7; 22 
miles west of Rock Springs, 2 ; Runge, 1 ; San Antonio, 63 ; San 
Diego, 3; Santa Tornas, 9; Velasco, 8; Waring, 1. 



(PI. II J, fig. 4.) 

Peromyscus texanus mesomelas Osgood, Proc. Biol. Soc. Wash., XVII, pp. 
57-58, March 21, L904. 

Type locality. — Orizaba. Veracruz, Mexico. 

Geographic distribution. — Humid tropics of central Veracruz and 
northern Puebla, Mexico. 

Characters. — Most similar to P. I. texanus; color darker; tail 
shorter ; hind foot larger ; a small pectoral spot present ; adolescents 
with an intense black dorsal stripe. 

Color. — Adult: General effect of upperparts pale Prout brown, 
produced by fawn ground color with a liberal mixture of dusky; 
sides practically unicolor with back; no definite dusky markings 
about head; underparts creamy white, except a small but distinct 
pectoral spot of fawn color; ears dusky with whitish edges; feet 
white, 'ankles' dusky brownish: tail bicolor. Immature: Similar 
in general to adult, but more sooty; sides dark mouse gray, tinged 
with fawn and bordered by a narrow fawn-colored lateral line; a 
broad stripe in median dorsal region intense black; 'ankles' sooty; 
tail indistinctly bicolor. 

Skull. — Similar to that of P. I. texanus, but with braincase averag- 
ing slightly larger and wider; nasals rather long and palatine slits 
usually corresponding. 

Measurements. — Type: Total length, 169; tail vertebras, 76; hind 
foot, 23; ear from notch (dry), 13.5. 

Type specimen. — No. 58210 U. S. National Museum, Biological 
Survey Collection. $ adult. Jan. 20, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — Although this form is very well characterized, there 
seems to be no doubt that it is connected, through P. I. texanus, 
with P. 1. tornillo and others of the same group. Specimens from 
Eio Verde, San Luis Potosi, are quite evidently intermediate, and a 
series from Metlaltoyuca, Puebla, while distinctly referable to meso- 
melas, shows some tendencies toward texanus. P. mesomelas is also 
related to P. affinis, which is a much paler form and not apt to be 
confused with it. Like texanus and affinis, it has short and relath T ely 
harsh pelage somewhat different from that of most other Mexican 

Specimens examined. — Total number 31, from localities in Mexico, 
as follows : 

Puebla: Metlaltoyuca, 15. 

Veracruz: Mirador. 1: "Mexico" (Salle) 5; Orizaba, 10; Rio Blanco, 2 
(not typical) ; San Andres Tustla, 1. 



Peromyscus texanus castaneus Osgood, Proc. Biol. Soc. Wash., XVII, pp. 58-59, 
Mar. 21, 1904. 

Type locality. — Vicinity of Yohaltun, Campeche, Peninsula of 
Yucatan, Mexico. 

Geographic distribution. — Known only from the vicinity of the 
type locality. 

Characters. — Similar to P. I. mesomelas, but smaller and more 
ferruginous ; underparts without pectoral spot ; adolescents without 
black dorsal stripe ; skull and teeth small. 

Color. — Type, in fresh pelage: General color of upperparts be- 
tween Prout brown and burnt umber, clearer on sides, darker on 
back; ground color rich dark fawn; no definite lateral line; under- 
parts pure white ; feet white, ' ankles ' brownish. Topotype Xo. 
107982, in slightly worn pelage : Sides and upperparts nearly uni- 
form cinnamon rufous, with scarcely any dusky admixture and only 
a narrow line on back somewhat deeper colored than rest of upper- 
parts. Immature : As in adult, but grayer. 

/Skull. — Rather small and light; braincase relatively narrow; 
nasals and palatine slits short; molar teeth small; otherwise similar 
to P. I. mesomelas. 

Measurements. — Average of 10 adult topotypes: Total length, 163 
(156-169) ; tail vertebra?, 73 (68-79) ; hind foot, 21.5 (20-22) ; ear 
from notch (dry), 12.5 (11.3-13.6). 

Type specimen. — No. 107980 U. S. National Museum, Biological 
Survey Collection. $ adult. December 19, 1900. E. W. Nelson 
and E. A. Goldman. Specimen practically perfect. 

Remarks. — P. I. castaneus is slightly darker than P. I. cozumelae, 
which is closely related. P. cozumelae differs chiefly in larger size 
and heavier teeth. No satisfactory specimens from the humid trop- 
ical region between Orizaba and Yohaltun are at hand, but castaneus 
is not sufficiently different from mesomelas to warrant full specific 
rank. P. affinis is a related form of the adjacent arid tropics, and 
much paler than either castaneus or mesomelas. 

Specimens examined. — Total number 25, all from the type locality. 


Hesperomys (Vesperimus) affinis Allen, Proc. U. S. Nat. Mus., XIV, pp. 195- 

196, July 24, 1891. 
Peromyscus affinis Allen and Chapman, Bull. Am. Mus. Nat. Hist., N. Y., IX, 

p. 7, Feb. 23, 1S97. 
Peromyscus m usculoides Merriam, Proc. Biol. Soc. Wash., XII, p. 121, Apr. 

30, 1S9S. — Cuicatlau, Oaxaca, Mexico. 


Type locality. — Barrio," Isthmus of Tehuantepec, Oaxaca, Mexico. 

Geographic distribution.- — Arid tropical parts of southern and 
central Oaxaca; northeast to southern Veracruz and parts of Yuca- 

Characters. — Similar to P. I. texanus and P. I. mesomelas, but 
slightly larger-; color much as in texanus, decidedly paler than in 
mesomelas or eastaneus; skull slightly larger and heavier than in 

Coli))-. Almost exactly as in P. I. texanus; general color of upper 
parts fawn, in fresh pelage mixed with dusky, forming an imperfect 
dark dorsal stripe, and in worn pelage mixed with cinnamon ; under- 
parts creamy white, rarely with a small fawn pectoral spot: feet- 
white, ' ankles ' pale brownish ; tail brownish fawn above, white below. 

Skull. — Similar to that of P. I. mesomelas. but somewhat larger; 
anterior part of zygoma heavier; infraorbital plate of zygoma wider; 
interorbital constriction averaging wider. 

Measurements. — Two adult males from Tehuantepec, Oaxaca: 
Total length, 182, 180; tail vertebrae, 84, 81 : hind foot, 24. 22. Aver- 
age of 10 adults from Cuicatlan. Oaxaca: 185: 84.5; 22.5; ear from 
notch (dry), 14.3 (13.5-15). 

Type specimen. — No. ff f-f U. S. National Museum. $ adult. Oct. 
30, 1868. F. Sumichrast. Skin soiled and discolored, particularly 
on underparts; right hind foot broken off and tied on with thread: 
tail vertebra' not removed. Labeled in Coues's hand " melanophrys?" 
and later "mexicanus?" by someone else. Skull in fair condition, 
but still with considerable flesh adhering to it ; right zygoma slightly 

Remarks. — Externally, this form is scarcely distinguishable from 
P. I. texanus. It averages slightly larger, and its skull is more elon- 
gate, besides being decidedly heavier in the infraorbital region. Its 
intergradation with P. I. mesomelas, the form of the adjacent 
humid tropics, is scarcely to be doubted. However, two specimens 
from Otatitlan, Veracruz, near the edge of the humid region, seem 
distinctly referable to affinis. 

Specimens examined. — Total number 76, from localities in Mexico 
as follows : 

Oaxaca: Barrio, 3; Cuicatlan, 1G; Guichicovi, 1; Huilotepec, 5; Re- 

forina, 10; Santa Efigenia, 1; Tehuantepec, 5. 
Veracruz: Otatitlan, 2; Pasa Nueva, 22. 
Yucatan: Chichenitza, 11 (approaching eastaneus). 

« Barrio usually means a suburb. Sumichrast's specimens are labeled thus: 
"Tehuantepec (Barrio)." This might mean a suburb of the city of Tehuante- 
pec, but since there is a town called Barrio near the middle of the Isthmus of 
Tehuantepec, and since Sumichrast labeled specimens from other towns in 
Oaxaca in this manner, it seems pi'obable that the town of Barrio was meant. 
As the same species occurs at both places the question is not important. 



(PI. TIT, fig. 3.) 

Peromyscus eoznnielcp Merriam, Proc. Biol. Sue. Wash., XIV, p. 103, .Inly 11), 

Type locality. — Cozumel Island, off coast of Vucalan. Mexico. 

Geographic distribution. — Cozumel Island. 

Characters. — Size about as in P. 1. affinis; color about intermediate 
between that of affinis and of castaneus; skull larger and heavier 
than in castaneus; teeth heavier than in affinis. 

Color. — Slightly duller and paler than in P. 1. castaneus; otherwise 
similar; slightly darker and more ferruginous than in P. 1. affinis. 

Skull. — Decidedly larger and heavier than in P. 1. castaneus; teeth 
heavier; audital bulla^ larger; infraorbital region heavier. Most 
similar to that of /'. /. affinis; teeth averaging slightly larger; brain- 
case averaging a trifle shallower; audital bulla^ usually a trifle larger. 

Measurements. — Average of 10 adult topotypes: Total length, 184 
(163-198) ; tail vertebrae, 83.8 (76-90) ; hind foot, 23.3 (22-24) ; ear 
from notch (dry) 14.6 (13.7-15.7). 

Type specimen. — No. 108449 U. S. National Museum, Biological 
Survey Collection. $ adult. Apr. 11, 1901. E. W. Nelson and E. A. 
Goldman. Specimen in perfect condition. 

Remarks. — P. I. cozumelae is so closely related to P. I. castaneus 
and P. 1. affinis that it seems best to treat it as a subspecies. It is 
most closely similar to P. 1. affinis, being only a shade darker and 
having no constant cranial distinctions. Some skulls of cozumelae 
are absolutely indistinguishable from others of affinis. 

Specimens examined. — Total number 19, all from the type locality. 

Key to subspecies of Peromyscus gossypinus. 

Size large : hind foot 22—26, i liiefly north of peninsular Florida. 

Size very large ; color averaging paler. Northern Alabama to eastern Texas. 

/'. .</. megacephalus. 
Size not so large; color averaging darker. Southern Virginia to northern 

Florida, west to Louisiana P. gossypinus. 

Size smaller: hind foot 20-22. Chiefly peninsular Florida and adjacent islands. 

Darker. Mainland P. .'/• palmarius. 

Paler. Insular.- P .'/• anastasae. 

PEROMYSCUS COSSYPINUS (Le Conte). Cotton Mofse. 
(PI. Ill, fig. 2.) 

Hyp [udaeus] gossipinus Le Conte, McMurtrie's Cuvier's Animal Kingdom. I. 

append., p. 434, 18.31 — nomen nudum. 
fMus carolmensis Aud. & Bach.. Jour. Acad. Nat. Sci. Phila., pp. 306-307, L841. 

South Carolina. (Indeterminate.) 
Hesperomys gossypinus Le Conte, Proc. Acad. Nat. Sci. Phila., VI, pp. 411-412, 




[no. 28. 

Hesperomys cognatus Le Conte, Proc. Acad. Nat. Sci. Phila., p. 442, 1855. 

Perom.yscti8 gossypinus Rhoads, Proc. Acad. Nat. Sci. Phila., p. L89, 1896. 
Peromyscus gossypinus nigrieulus Bangs, Proc. Biol. Soc. Wash., X. pp. 124- 

125, Nov. 5, 1896. — Burbridge, Plaquemines Parish, Louisiana. 

Type locality. — Le Conte Plantation, near Rieeboro, Liberty 

County, ( ia. 

Geographic distribution. — Lowlands of the southeastern United 

States from the Dismal Swamp, Virginia, to northern Florida and 

west to Louisiana. Lower Austral zone. 

Characters. — Size medium or rather large (hind foot 22-24) ; tail 

shorter than head and body, not very sharply bicolor, clothed with 

rather short hairs; color rather dark, in most pelages with an ex- 
tensive dark dorsal 
area. Most similar 
in general appear- 
ance and character 
of pelage to P. leu- 
copus, hut larger 
and darker. 

Color. — Unworn 
pelage : Ground col- 
or of upperparts 
bright rufescent 
cinnamon between 
the cinnamon and 
cinnamon rufous of 
R i d g w a y ; entire 
upperparts heavily 
mixed with blackish 


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.MlESS^/. R O MB MM, 

— i 

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^ +l AlllllMlli lir 

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11 111 ill 1 1 





P. gossypinus. 








P S 




-Distribution of Peromyscus gossypinus and 

appearing as coarse 
lines which, al- 
though close together, do not blend with the ground color ; dusky mix- 
ture predominating on middle of back, appearing as a broad stripe 
from the shoulders to the base of the tail ; top of head and shoulders 
somewhat grayer than sides; a narrow orbital ring slightly widened 
anteriorly and posteriorly: cars dusky brownish, scarcely or not at all 
edged with whitish ; underparts white or creamy white usually with 
a very strong creamy tinge in pectoral region; feet white; forearm 
often dusky or slightly rufescent and dusky: tail blackish brown 
above, white below. Worn pelage: Sides bright cinnamon rufous or 
deep russet slightly toned down by a thin mixture of darker pale- 
brownish hairs: middle of back darker, varying from russet to Prout 
brown. Adolescent pelage : Ground color of upperparts pale cinna- 
mon or isabella color thickly mixed with blackish which predominates 
on dorsum and is rather sharply contrasted with the sides. 


Skull. — Rather large and heavy; zygomata heavy anteriorly; pre- 
maxillae slightly expanded laterally; palatine slits rather broadly 
open, their outer sides not parallel; interpterygoid fossa broad and 
square anteriorly. Similar in general to that of leucopus, but larger 
throughout; teeth decidedly longer. 

Measurements. — Two adult topotypes: Total length, 160, 171; tail 
vertebrae, 72, 71; hind foot, 21, 23; ear from notch (dry), 15.7. 
Average of 12 adults from St. Marys, Ga. : 177.6; 70; 22A Of 10 
adults from Dismal Swamp, Virginia: 181.6 (175-190); 81 (70- 
88); 22.9 (22-24). Of 5 adults from Belair, La.: 178 (170-184); 
74.6 (71-78); 22.7 (22-23). 

Type .specimen. — Xo type was designated in the original descrip- 
tion. Several specimens collected in Georgia by Le Conte have been 
in the IT. S. National Museum. Xo. 4704 remains there still and may 
perhaps be regarded as a cotype, though there is no positive evi- 
dence that it was in Le Conte's hands at the time the description was 
written. It is in fair condition. The skull and tail vertebrae are 
inside the skin. It was catalogued April 3, 1861. Xo. 752 Collec- 
tion of Academy of Natural Sciences, Philadelphia, also has claims. 
It is labeled, " Georgia Dr. Le Conte," and was catalogued January, 
1860. Xo. 5275, Museum of Comparative Zoology, Cambridge, Mass., 
is still another. 

Remarks. — Although evidently very closely related to leucopus, 
P. gossypinus appears to be distinct. Both occur at the same locali- 
ties through much of the northern part of the range of gossypinus 
and everywhere seem to maintain themselves distinct. The only cer- 
tain character for distinguishing them in all conditions of pelage is 
that of size, for although gossypinus is almost always darker in un- 
worn pelage, specimens occur which are very similar to leucopus in 
certain stages of worn pelage. The skull and teeth of gossypinus 
are of the same general character as those of typical leucopus but 
decidedly larger, although if specimens of the smaller forms of 
gossypinus be compared with those of larger forms of leucopus 
scarcely any difference in size appears. The subspecies of gossypinus 
are all slight, differing mainly by average characters of size and 
amount of dusky mixture in the pelage. Typical gossypinus itself 
is the darkest form and 'nigriculus ' does not appear to differ from it. 
A single specimen from Bogue Beach, X. C, is very pale and may 
represent a slight coast form. 

Two specimens now in the British Museum and recently received 
in the Tomes collection may perhaps be considered as paratypes of 
Le Conte's Hesperomys cognatus. On the old labels is written 
" From Major Le Conte, Feb. 1858. Hesperomys cognatus" Both 
are typical examples of Peromyscus gossypinus. 


Specimens examined. — Total number 450, from localities as fol- 

Alabama: Castleberry, •'(: Elmore, 1 : Mobile liny, 10; Montgomery, 2. 

Florida: Amelia Island, 1: Burnside Beach, 7: Oartersville, '.'>: Gaines- 
ville, 58; Jacksonville, l: Milton, 1: New Berlin, 35; Summer 
Haven, 1 ; Whitfield, 14." 

Georgia: Augusta, :!: Barrington, 6; Butler, 4; Hursman Lake, 2; Mont- 
gomery, '.»: Pinetucky, 22 : Riceboro, 21 : St. Marys, 36; Savannah, 2: 
Sterling, id. 

Louisiana: Belair, 6; Burbridge, 5; Gibson, Terre Bonne Parish, 56; 
Lecompte, 4: Powhatan Plantation, near Gibson, 28; Houma, 7: 
Lake Charles, 2: Tallulah, 5. 

Mississippi: Pay SI. Louis. 7: Washington, 13. 

North Carolina: Bertie County. :\: Bogue Peach. 1 (.aberrant); Curri- 
tuck, 2. 

South Carolina: Columbia, 2: Georgetown, 1: "South Carolina" (Le 
Conte), 6. 

Virginia: Dismal Swamp, 44. 


Sitomys megacephalus Rhoads, Proc. Acad. Nat. Sci. Phila., pp. 254-256, Sept. 

2:,. 1894. 
Peromyscus gossypinus mississippiensis Rhoads, Proc. Acad. Nat. Sci., Phila., 

p. 189, 1896. — Samburg, Tennessee. 
Peromyscus gossypinus Bangs, Proc. Biol. Soc. Wash., X, pp. 119-125, Nov. 5, 


Type locality. — Wooctville, Ala. 

Geographic distribution. — Northern Alabama and western Ten- 
nessee, west through Arkansas to eastern Oklahoma, and thence 
south through eastern Texas and western Louisiana. 

Characters. — Similar to gossypinus but averaging larger and paler. 

Color. — Unworn pelage: Ground color of upperparts slightly 
lighter than in gossypinus; dusky mixture less abundant on sides and 
less concentrated in middle of back; orbital ring very narrow or 
obsolete: underparts creamy white. Worn pelage: Slightly paler 
than in gossypinus; sides a lighter shade of russet; dorsum Mars 
brown to mummy brown, but this less extensive than in gossypinus. 
Adolescent pelage: Quite decidedly paler than in gossypinus; sides 
isabella color mixed with dusky, producing a general effect of broc- 
coli brown tinged' with fulvous; dorsum distinctly dusky, but less so 
than in gossypinus. 

Skull. — Similar to that of gossypinus, but decidedly larger and 
more elongate; rostrum and nasals longer. 

Measurements. — Average of 6 adults from Tennessee: Total length. 
183; tail vertebra?, 79.5; hind foot, 24.5; ear from notch (dry), 15.5 

Carneyie Museum. 


(15-16.3). Of 6 adults from eastern Texas: 196 (188-205); 84 
(78-90); 24 (23-26). 

Type specimen. — No. 3585 Collection of Academy of Natural Sci- 
ences, Philadelphia. $ (?) adult. H. E. Sargent. Specimen in 
alcohol, except the skull, which has been removed, and which is in 
fair condition, although not very thoroughly cleaned and somewhat 
broken about the foramen magnum. 

Remarks.- — The largest specimens of this form (and perhaps also 
the palest) come from eastern Texas and Oklahoma. It would there- 
fore be more satisfactory if the type had been obtained from this 
region. However, the type and specimens from western Tennessee 
are obviously nearer to the western form than to typical gossypinus. 
Specimens from central Mississippi appear to be intermediate be- 
tween megacephalus and gossypinus. The name megacephalus was 
referred to the synonymy of gossypinus by Bangs (1. c), although 
the type specimen was not examined by him. The skull of this type 
proves to be too large to belong with gossypinus, and although the 
skin in alcohol can not be trusted for color characters, there seems 
little doubt that it represents the form recognized by Bangs under 
the name mississippiensis. 

Specimens examined. — Total number 62, from localities as fol- 

Alabama: Scottsboro, 1; Woodville, •"». 

Louisiana: Chirks, 1; Foster. 4. 

Oklahoma: Red Oak, 1. 

Tennessee: Arlington, 10; Big Sandy. .°» : Clarksville, :( : High Cliff. 1; 

Lawrenceburg, 1 ; Samburg, 17. 
Texas: Jasper. ?> : Jefferson, 1: Long Lake. 1: Sonr Lake, 11; Tex- 

arkana, 1. 


Pcromyscus gossypinus palmarius Bangs, Proo. Biol. Soe. Wash.. X. p. 124. 
Nov. 5, 1S9G. 

Type locality. — Oak Lodge, east peninsula, opposite Micco, Bre- 
vard County. Florida. 

Geographic distribution. — Peninsular Florida. 

Characters. — Similar to gossypinus, but averaging smaller and 

Color. — Unworn pelage: Similar to that of gossypinus, but paler: 
ground color a shade lighter and dusky mixture more sparse, as a 
rule not so heavily concentrated in the middle of the back; orbital 
ring very narrow: underparts grayish white to creamy or even yel- 
lowish white, rarely with a small fulvous pectoral spot. 


Skull. — Similar to that of f/ossypinus, but averaging decidedly 
smaller; rostrum and infraorbital region lighter; teeth slightly 

Measurements. — Average of 7 topotypes: Total length, 178.8 
(172-183) ; tail vertebrae, 74.5 (G9-78) ; hind foot, 21.1 (20-22) ; ear 
from notch (dry), 14.7 (14-15). Of 20 topotypes: h 181; 71.8; 21.5. 

Type specimen. — No. 3224 Museum of Comparative Zoology, 
Cambridge, Mass., formerly in collection of E. A. and O. Bangs. 
9 adult. Feb. 23, 1895. O. Bangs. Specimen in good condition. 

Remarks. — Specimens from various parts of peninsular Florida 
are constantly smaller than typical gossypinus. The pale color shown. 
by many specimens is not so constant and can be considered only an 
average character. It is more pronounced in specimens from the 
coast beaches than in those from the interior, but on the whole it- 
seems best to refer all the material from peninsular Florida to one 

The type of pafonarius and a very small percentage of the large 
series of topotypes are unusually pale and scarcely distinguishable 
from comparable specimens of anastasae. If further study of local 
conditions at the type locality should prove that two forms occupying 
different habitats are found together there, it would then seem to be 
necessary to use the name palmarius for the pale form now called 
anastasae and supply a new name for the darker and more widely 
distributed form. However, the great preponderance of dark speci- 
mens from the type locality tends to indicate that the type is proba- 
bly an aberrant specimen rather than the representative of a well- 
defined form. The case might be construed also to the effect that 
pale coast forms are undergoing parallel differentiation at several 
points and that the same character (paleness) has been established 
independently on Anastasia and Cumberland islands and is only in 
its incipiency on the peninsula opposite Micco. 

Specimens examined. — Total number 523, from localities as 
follows : 

Florida: Anclote River, 32 (head 30, 12 miles up 2) ; Argo, 3; Auburn- 
dale, 3 ; Blitcli Ferry, Citrus County, 21 ; Canaveral, 18 ; Cape Ca- 
naveral, 2; Catfish Creek, 4; Charlotte Harbor, 2; Citronelle, 3 
Crystal River, 13; Eden, 1; Enterprise. 33; Eau Gallie, 2; Flamingo 
26 ; Fort Kissimmee, S ; Glenwood, 1 ; Georgiana, 2 ; Gulf Hammock, 2 
Jupiter Island, 4 ; Kissimmee, 9 ; Lake Arbuckle, 1 ; Lake Harney, 24 
Lake Hatchehaw, 4 ; Lake Kissimmee. 3 ; Lake Worth, 7 ; Miami, 51 
Miceo, 13 ; Mullet Lake, 25 ; Oak Lodge, opposite Micco, 161 ; Planter 
2 ; Port Richey, 2 ; Sawgrass Island, 4 ; Sebastian, 5 ; Tarpon Springs 

a Biological Survey Collection. 
b Bangs collection. 



Peromyscus anastasae Bangs, Proc. Bost. Soc. Nat. Hist, XXVIII, pp. 195- 

196, March, 1898. 

Peromyscus insulanus Bangs, supra cit., pp. 196-197 — Cumberland Island, 


Type locality. — Point Romo, Anastasia Island, Florida. 

Geographic distribution. — Sandy islands (possibly also parts of 
the mainland) of the eastern coast of Georgia and Florida. 

Characters. — Size about as in palmarius; color paler than in 
gossypinus or palmarius. 

Color. — Upperparts pale ochraceous buff rather lightly mixed 
with dusky, which is slightly or not at all concentrated in the mid- 
dorsal region ; orbital ring nearly or quite obsolete ; underparts 
white almost entirely concealing undercolor ; ears dusky ; tail bicolor, 
brownish dusky above, white below. Adolescents paler, more 
drabby, than in palmarius. 

Skull. — Practically as in palmarius, somewhat smaller than in 

Measurements. — Type : Total length, 165 ; tail vertebra?, 69.5 ; hind 
foot, 21; ear from notch, 16.5. Average of 6 adult topotypes: 
167.5; 69.5; 21.4. Average of 3 adults from Cumberland Island, 
Georgia : 171.7 ; 68 ; 21.6. 

Type specimen. — No. 7179 Museum of Comparative Zoology, 
Cambridge, Mass., formerly in collection of E. A. and O. Bangs. 
9 adult. Feb. 15, 1897. O. Bangs. Specimen in good condition. 

Remarks. — Although the pale forms from Anastasia and Cum- 
berland islands, respectively, are entirely isolated from each other 
and from the mainland forms, they seem to be absolutely alike and 
also are not different from certain aberrant (intermediate?) speci- 
mens from the mainland. Moreover, the mainland specimens most 
similar to them are not from localities immediately adjacent to the 
islands in question, specimens from St. Marys, Ga., Burnside Beach, 
Fla., etc., being typical gossypinus. 

Specimens examined.- — Total number 54, from localities as follows: 

Florida: Anastasia Island, 18. 
Georgia: Cumberland Island, 36. 

Key to subspecies of Peromyscus boylei. 

a. Habitat western United States and northern Lower California. 

b. Size smaller; hind foot 21-23. Western Texas to Pacific coast. 

1. Color darker. Northern Sierra Nevada Mountains and coast ranges north of 

San Francisco Bay P. boylei 

2. Color paler. Coast region of southern California to northern Lower Cali- 

fornia ; east to Colorado and western Texas P. b. rowleyi 

bb. Size larger ; hind foot 22-25. Arkansas to central Texas P. b. attwateri 

aa. Habitat Mexico (except Lower California) and Guatemala. 

b. Habitat western Mexico and adjacent islands, chiefly west of the 102d meridian, 
c. Size smaller ; hind foot 21-23 ; color paler, chiefly grayish Isabella color or pale 
ochraceous buff P. b. rowleyi 


cc. Size larger; hind foot 22-26; color darker, chiefly rich tawny or ochraceous. 

d. Larger. Tres Marias Islands P. b. madrensis 

dd. Not so large. Mainland of Mexico. 

1. Molars large; maxillary toothrow about 5; hind foot extensively dusky. 

Oaxaca and Guerrero p. b. evides 

2. Molars moderate ; maxillary toothrow less than 5 ; hind foot less exten- 

sively dusky. Southern Sonora to Jalisco P. b. spieilegiM 

bb. Habitat eastern and southern Mexico and Guatemala, chiefly east of the 102d 
e. Color largely rich tawny or ochraceous : hind foot extensively dusky ; molars 
large ; maxillary toothrow about 5. 

1. Color darker and richer. Veracruz and Puebla P. b. aztecus 

2. Color paler. Oaxaca and Guerrero P. b. evides 

cc. Color duller and more mixed with dusky : hind foot less extensively dusky 

(usually white except tarsal joint); molars smaller; maxillary tooth- 
row less than 5 P. b. levipes 

(PI. IV, %. 1 : pi. VII. tig. r».) 

Hesperomys boylii Baird, Proc. Acad. Nat. Sci. Phila., VII, pp. 335-336, April, 

1 855. 
Sitomys robustus Allen, Hull. Am. Mus. Nat. Hist., V, pp. 335-330, Dec. 16, 

1893 — Lakeport, Lake County, Calif. 
Peromyscus boylii Mearns, Proc. U. S. Nat. .Mus., XIN. p. 130, May 25, 1896. 

Type locality. — Middle Fork American River, Eldorado County, 
Calif., near site of present town of Auburn. 

Geographic distribution. — West slopes of the Sierra Nevada moun- 
tains from the vicinity of Yosemite north to Mount Shasta, thence 
along the east slopes of the coast ranges nearly to San Francisco Bay. 
Upper Sonoran and Transition zones. 

Characters. — Size medium (hind foot 21-23), about as in truei, 
larger than in gambeli; tail long, equal to or longer than head and 
body, somewhat penicillate and rather coarsely hairy throughout, the 
annulations usually being obvious; ears medium, smaller than in 
truei and gilberti; proximal two-fifths of under side of hind foot 
hairy: coloration not peculiar, much as in gilberti and gambeli; 
preauricular tufts without white. 

Color. — Unworn pelage: General effect of upperparts hair brown 
to sepia ; ground color pale buffy cinnamon heavily and uniformly 
mixed with dusky without any decided concentration in middle of 
back: lower face, arms, and narrow lateral line nearly clear pale 
ochraceous buff; a narrow blackish orbital ring; ear tufts same as 
upperparts, never containing white hairs, but often showing a soft 
blackish tuft at the base of the upper margin of the ear; ears dusky 
narrowly edged with whitish: underparts creamy white; feet white, 
' ankles ' rather extensively dusky ; tail brownish above, white below. 
Worn pelage : Upperparts varying from Mars brown and russet to 
pale cinnamon uniformly mixed with brownish dusky, which varies 
in amount according to degree of wear; orbital ring, dark marking 
on hind legs and ' ankles,' and upper side of tail paler, more brown- 




ish, than in unworn pelage. Adolescent pelage: General effect of 
upperparts varying from drab to hair brown with a tinge of fawn, a 
pale ochraceous buff lateral line usually evident. 

Skull. — Size medium, decidedly larger than in gambeli and rubidus 
but somewhat smaller than in truei and gilberti; rostrum depressed 

P. O. madrenj-ij 
P. O. aztecus 

Fig. 4. — Distribution of Peromyscus boylei and subspecies. 

anteriorly: zygomatic width least anteriorly; infraorbital region 
relatively weak; braincase somewhat rounded but smaller and less 
inflated than in truei; audita! bullae decidedly smaller and less orbi- 
cular than in truei; teeth medium, much larger than in gambeli and 
rubidus, about equaling those of truei. 


Measurements. — Average of 10 adult topotypes : Total length, 197 
(183-202) ; tail vertebrae, 103 (92-112) ; hind foot, 22 (21-23) ; ear 
from notch (dry), 16.4 (15.3-17.5). 

Type specimen. — No. tVtV U. S. National Museum. Collected by 
Dr. C. C. Boyle. Entered in Museum catalogue in 1854. Skin 
formerly in exhibition series, now removed from stand but still in 
crouching position, as originally mounted, Avith tail raised over back. 
Color much faded from exposure to light, chiefly pale buffy cinna- 
mon. Tail somewhat cracked, but coarse annulations and hairy 
covering distinct. A large patch of fur gone from right side of 
body. Skull with zygomata somewhat broken, otherwise perfect. 
Tail vertebra; preserved with skull. 

Remarks. — Typical P. boylei appears to be confined to the State 
of California. There is no obvious reason why it should not occur 
also in the mountains of southern Oregon, but considerable collecting 
there has failed to reveal it. However, although it sometimes ranges 
into the Canadian zone, it is evidently of southern extraction and is 
connected with various intergrading forms which range throughout 
most of Mexico and even into Guatemala. Although occasionally 
found in the valleys, it is much more common in the mountains. 
From other species of California, it may be recognized usually by 
its coarsely haired penicillate tail, medium-sized ears, and cranial 
characters. P. boylei is perhaps most apt to be confused with gil- 
berti, which approaches it in size and color very closely. Its ears 
average smaller than in gilberti, its tail is more coarsely haired, and 
the coarser annulations are more exposed. If external characters 
fail, it may be distinguished from gilberti with certainty by its 
decidedly smaller audital bullae. 

In the southern Sierra region boylei intergrades with the paler 
form rowleyi, and many specimens may be found that resemble one 
about as much as the other. A series from the lava beds of Fall 
River Valley. Shasta County, are unusually dark colored, but the 
divergence is slight. 

Specimens examined. — Total number 254, from localities as fol- 
lows : 

California: Middle Fork American River, near Auburn, 34; Baird, 4; 
Bartlett Springs, 2; Battle Creek, 4; Berger Creek, 1; Beswick, 6; 
Bully Choop Mountains, 5; Cassel, 2; Chico (10 miles northeast), 9; 
Chinese, 2; Coarsegold, 2; Coulterville, 1; Dana, 2: Downieville, 3; 
Eel River, 4; Eel River, near South Yolla Bolly Mountain, 19; Etna, 
Salmon Mountains, 6; Fall Lake, Fall River Valley, 6 (aberrant): 
Forest Hill, Placer County. 2: Fresno Flat, 7: Fyffe, 4; Guenoc, 2; 
Hurleton, 10 ; Lakeport, 1 : ° Leesville, 8 ; Lower Lake, 14 ; Milford, 
3 ; Montgomery, 1 ; Mount Shasta, 1 ; Mountain House, Butte County, 
4; Oroville, 2; Quincy, 2; Salt Springs, 6; Scott Valley, 4; Sierra 

a Collection of Leland Stanford, jr., University. Type of ' robustus.' 


City, 1; Slippery Ford. 1i>; Snow Mountain, Colusa County. 36; Still- 
water. 2 ; Susanville, 1 ; Tower House, 1 : Upper Lake, 2; Yosemite, 18. 


Sitomys rowleyi Allen, Bull. Am. Mus. Nat. Hist., X. Y.. V, pp. 76-78, Apr. 28, 

Sitomys major Rhoads, Am. Naturalist, XXVII, p. 831, Sept.. ] 893. — Squirrel 

Inn, San Bernardino County, Calif. 
Sitomys rowleyi pinalis Miller, Bull. Am. Mus. Xat. Hist., X. Y., A', pp. 331-334, 

Dee. 16, 1S93. — Granite Gap, Grant County, X. Mex. 
Peromyscus boylii rowleyi Mearns, Proc. U. S. Xat. Mus., XIX. p. 139, May 

25, 1896. 
Peromyscus boylii penicillatus Mearns, Proc. U. S. Xat. Mus., XIX, p. 139, 

May 25, 1896. — Franklin Mountains, near El Paso, Tex. 
Peromyscus gaurus Elliot, Field Columbian Museum, Chicago, Zoo!. Ser., Ill, 

pp. 157-158, Apr., 1903. — San Antonio, San Pedro Martir Mountains. Lower 

Peromyscus parasiticus Elliot, Field Columbian Museum, Chicago, Zool. Ser., 

Ill, p. 244, Jan., 1904.— Lone Pine, Calif. 
Peromyscus metallicola Elliot, Field Columbian Museum, Chicago, Zool. Ser., 

Ill, p. 245, Jan., 1904. — Provideneia Mines, Souora, Mexico. 

Type locality. — Noland Ranch, San Juan River, Utah. 

Geographic distribution. — Mountains of southern California, 
northern Lower California, southern Nevada, Utah, Colorado, Ari- 
zona, New Mexico, western Texas, and south in Mexico chiefly on the 
eastern slopes of the Sierra Madre to central -Zacatecas and north- 
western San Luis Potosi. 

Characters. — Size, proportions, and cranial characters practically 
as in P. boylei; color paler. 

Color. — Unworn pelage: General effect of upperparts wood brown 
to isabella color; ground color ochraceous buff uniformly sprinkled 
with dusky; sides like back, except a relatively broad lateral line of 
ochraceous buff unmixed with dusky; nose and postorbital region 
grayish; narrow orbital ring blackish; ears dusky, faintly edged 
with whitish; underparts cream white; tail dusky brownish above, 
white below; feet white, dusky of hind legs extending to tarsal joints, 
but not sharply contrasted. Worn pelage: General effect, of upper- 
parts varying from clay color to vinaceous cinnamon and from that 
to cinnamon (No. 20, PI. Ill, Ridgway), quite decidedly paler than 
in boylei. 

Skull. — Practically as in boylei. possibly averaging a trifle larger. 

Measurements. — Average of 10 adults from Bluff City. San Juan 
River, Utah: Total length, 191 (180-207) ; tail vertebra". 99 (91-109) ; 
hind foot, 21.6 (21-23) ; ear from notch (dry), 17.2 (10.6-18). 

Type specimen. — No. fff$ American Museum of Natural History, 
New York. ? adult . April 20. 1892. Chas. P. Rowley. Skin in 

6620.x— No. 28—09 10 


fair condition, in bright slightly worn pelage; end of tail slightly 
injured. Skull in good condition. 

Remark*. — This pale form of boylei has a wide range throughout 
which it shows comparatively little variation. Nearly all California 
series of rowleyi are the merest shade deeper colored than typical. 
thus being intermediate between boylei and rowleyi. This includes 
(specially specimens from the coast valleys and low ranges of moun- 
tains from Monterey County to northwestern Lower California. 
The difference is so slight, however, that it can scarcely be detected 
in small series or individuals and is apparent only on comparison 
of very large series. Specimens from the east side of the southern 
Sierras and also those from the San Bernardino Mountains, includ- 
ing the type of ' major, 1 do not show the slightest tendency toward 
boylei, but are practically identical with rowleyi. On the whole 
it seems best to include all southwestern specimens of this group 
under the name rowleyi. The difference between typical boylei and 
rowleyi is only in shade of color, and the attempt to recognize an 
intermediate shade does not seem advisable. Intergradation with 
attwateri is shown by specimens from western Texas, which are large 
but pale colored. The type of ' 'penicillatus ' is an abnormally pale 
individual, but a series from the Franklin Mountains near the type 
locality does not differ from typical rowleyi. Specimens from the 
type locality of ' />i/ialis* do not differ from others in comparable 
condition from the vicinity of the type locality of rowleyi. 

Most Mexican specimens of rowleyi show slight tendencies toward 
spicilegus, being slightly deeper colored. Specimens from Lower 
California (' gaums 1 ) have rather long tails but no longer than are 
often found in various other parts of the range of the form. 

As boylei is apt to be confused with gilberti, so also is rowleyi 
similar to truei. As a rule, however, rowleyi has decidedly smaller 
ears, less silky pelage, and a coarser tail than truei and hence may be 
distinguished without recourse to the skull, in which the audital 
bullae are much smaller than in truei. It also much resembles nasu- 
tus, which is a larger species with a longer rostrum. 

Specimens examined. — Total .number 1,270, from localities as 
follows : 

Arizona: Apache County, 1: Bradshaw City, 13; Chiricahua Moun- 
tains. 30: Fort Bowie. 5; Fort Huachuca, 6; Fort Whipple, 1; 
Grand Canyon, 6: Holbrook. 1; Huachuca Mountains, 133: Hualpai 
Mountains, S ; Xogales, 6 ; Oracle, 1 ; Painted Desert, Little Colorado 
River, 1: Pinal County, 14: Prescott, 5; Santa Catalina Moun- 
tains. 8: Show Low. 2; Walnut, 1 : Warsaw. 1: White Mountains, 2. 

California: Aguanga, 2; Arroyo Seco, near Paraiso Springs, 6; Ballena. 4 : 
Bergman, 2: Balcon Mountain, 1; Camp Badger, 4: Carmel River, 
40; Carpenteria, 2; Chihuahua Mountains. San Diego County. 2: 
Coahuila Mountains. Riverside County, 1 : east base Coast Range, 
San Diego County. 1 : Cone Peak. Monterey County. 4: Cuyainaea, 7; 


Densniores, Riverside County, 7; Dulzura, 2: Eshorn Valley, Tulare 
County. 2: Gaviota Puss, 11; Glendora, 1: Hemet Mountain. .'! : 
Independence Creek, 2; Jacumba, .'!: Julian, 1 ; Kaweah, 1; Kaweah 
River, 2; Kern River, 13; Kern River Lakes. 1; Laguna Mountains, 
San Diego County, <>; Laguna. 11; Las Virgines Creek. 1: Lone 
Pine, 18; Milo, 2: Mission Santa Ynez, 7; Mohave, 1; Mono Fiats. 
Santa Barbara County, 4: Morans, 1; Mountain Spring, San Diego 
County, 1: Nellie. 2: Nofdhoff, 6; Oak Grove, 1; Olancha ('reek, 2: 
Owens Lake, 15; Pine Valley. Monterey County, 8; Piute Moun- 
tains, 2: Pleyto, 1: Porterville. 3: Pozo, 10; Providence Moun- 
tains, 3; San Bernardino Mountains, 37; San Emigdio Canyon, 7; 
San Gabriel Mountains (Strain Camp), 12; San Jacinto Moun- 
tains, 20: San Miguelito, 1: San Rafael Mountains, Santa Barbara 
County, 18; San Simeon, 11; Santa Ana Mountains, 2: Santa Lucia 
Peak, 3; Santa Paula, 1; Santa Ynez River, (i; Santa Ysabel, 27; 
Smith Mountain, San Diego County, 1: south fork Kern River, 13; 
Springville, 5; Sur River, 4: Tassajara Creek, 22; Tehachapi, 4; 
Tejon Canyon, 4; Three Rivers. 23: Ventura River, 14; Walker 
Pass, 2: Witch Creek. 0; Zaca Lake, 6, 

Chihuahua: Balleza, 3: Colonia Garcia, 11 ; Colonia Juarez, 2; Parral, 5; 
San Luis Mountains, 2. 

Colorado: Arboles, 1: Cortez. 2:" Coventry, 5; Mesa Verde, 2; Salida, 1." 

Durango: Arroyo de Bucy, 1 ; Cienega de las Yacas, S; Durango, 1; La 
Boquilla, (>: Matalotes, 7: Rancho Santuario, 24: San Gabriel, 16. 

Lower California: de las Fresas, 7: Hanson Laguna, 10; La 
Grulla, 3; Naehoguero Valley, 10; Palomar, 3: Rancho San Antonio, 
16; San Matias Pass, 2; San Pedro Martir Mountains, 6. 

Nevada: Charleston Mountains, 5. 

New Mexico: Alma, 4; Animas Peak, 17; Animas Valley, 4; Aztec, 12; 
Rig Hatchet Mountains, 16 : Burro Mountains, 6 : Capitan Mountains, 
23; Clayton, 4; Copperton, 1 : Corona, 12: Dry Creek, Socorro Comity. 
2; Emery Peak, 4; Florida Mountains, 3; Folsom, 6; Fort Wingate, 1; 
Gallo Canyon, 2: Gallup, 1; Gila National Forest. 2; Glenwood, 1; 
Glorieta, 1: Granite Gap, 1; Jicarilla Mountains, 23; La Plata, 1: 
Las Vegas, 5: Manzano Mountains, 40; Mogollon Mountains, 2: 
Organ City, 2: Organ Mountains, 8; Raton Range, 4; San Andres 
Mountains, 7; Sandia Mountains, 17; San Pedro, 3: Santa Rosa, 8; 
Sierra Grande, 5 ; Silver City, 1 ; Tucumcari, 1. 

San Luis Potosi: Mountains near Jesus Maria, 4. 

Sonora: Huasavos Mountains, 10; Providencia Mines, 7; San Luis Moun- 
tains, 4; San Jose Mountains. 4; Santa Cruz River, 2; Sierra 
Patagones, 20. 

Texas:'' Rig Spring, 1 ; Franklin Mountains, 12 ; Ozona, 3 ; Rock Springs. 1. 

Utah: Bluff, 45; Noland Ranch, 10; Ogden, 2: Santa Clara Creek, 2. 


Peromyscus attwateri Allen. Bull. Am. Mus. Nat. Hist., X. Y., VII, pp. 330- 

331, Nov. 8. 1895. 
Peromyscus bcllii* Bangs, Proc. Biol. Soc. Wash.. X, p. 137. Dec. 28, 1896. — Stil- 

well, Okla. 

" Collection of E. R. Warren. 
''All approaching attwateri. 


Peromy8CU8 boylei laceyi Bailey, N. Am. Fauna No. 25, pp. «> ( .t-lOO, Oct. 24, 

1905 Turtle Creek, Kerr County, Tex. 
Peromyscus boylii attwateri Mearns, Bull. U. S. Nat. Mus. X<». 56, p. 42:>, April 

13, 1907. 

Type locality. — Turtle Creek, Kerr County, Tex. 

Geographic distribution. — South central and parts of western 
Texas; north to eastern Oklahoma, central Missouri, and southern 
Kansas. Chiefly confined to rocky cliffs in upper Sonoran zone. 

Characters. — Similar to rowleyi hut larger (hind foot 22-25) ; color 
darker and richer, practically as in boylei. Similar to laceianus but 
larger and darker and always with a distinct dusky marking on the 
tarsal joint ; skull and molar teeth smaller. 

Color. — Unworn pelage: Almost exactly as in boylei; ground color 
of upperparts pale cinnamon, thoroughly mixed with fine lines of 
dusky: head, particularly about nose and orbital region, somewhat 
grayish; dusky orbital ring rather narrow: lower sides of face, axil- 
lary region, and narrow lateral line ochraceous buff; dusky of hind 
leg continued over tarsal joint and encroaching slightly on upper 
side of hind foot; underparts creamy white, occasionally with an 
ochraceous buff pectoral spot. Worn pelage: Upperparts varying 
from cinnamon to russet and pale cinnamon rufous, variously mixed 
with dusky or brownish 

Skull. — Similar to that of boylei and rowleyi but larger; braincase 
higher, more inflated; audital bulla 1 and molar teeth decidedly larger. 

Measurements. — Average of 10 topotypes: " Total length, 196 (187- 
216) ; tail vertebra-. 100 (90-110) ; hind foot, 21 (20-23). Hind foot 
of type (dry). 23.5. Average of 10 adults from Stilwell, Okla.: 
Total length'. 205 (196-218) : tail vertebrae, 103 (97-112) ; hind foot. 
21.3 (23-25) ; ear from notch (dry), 16.2 (15.5-17.2). 

Typt specimen. — No. VttV American Museum of Natural 
History. Xew York. ? adult. Mar. 12, 1895. H. P. Attwater. 
Skin in good condition. Skull with zygomata and pterygoids slightly 
broken ; last left upper molar missing. 

Remarks. — Although the wide range of the pale form rowleyi is 
interposed between that of typical boylei and of attwateri, the latter 
two are very similar. In general, attwateri has a somewhat grayer 
face than boylei, and the dusky hairs of the back show more distinctly 
as lines, but many specimens of each are practically indistinguishable 
by color alone. The large size and rather rich color of attwateri are 
most developed in the northern part of its range, in the Wichita 
and Ozark mountains. Specimens from western Texas in the Da^is 
Mountains and vicinity seem referable to attwateri, but do not differ 
greatly from others from Colonia Garcia, Chihuahua, which have 

From original description. 


been referred to rowleyi, and which may be considered as approach- 
ing either attwateri or spicilegus. 

It does not seem possible to recognize 'P. beMusf for though it 
may differ by extremely slight average characters from attwateri 
from the type locality, it merely represents the extreme of a differen- 
tiation away from rowleyi which is well established at the type lo- 
cality of attwateri The recognition of both attwateri and ' Leilas ' 
would therefore make attwateri an extremely slight and practically 
indefinable intermediate between rowleyi and ' bellus? The name 
laceyi is a pure synonym of attwateri, having been based upon the 
same species from the same locality on the supposition that the name 
attwateri applied to the form of peetoralis now called laceianus. 

Specimen* examined. — Total number 273, from localities as fol- 
lows : 

Arkansas: Batesville, 3. 

Kansas: Cedarvale, 4. 

Oklahoma: Dougherty, 21: Redland, 2; Red Oak, 8; Stilwell, 37; 

Wichita Mountains I vicinity of Mount Scott and Mount Sheridan), 

Texas: Boerne, 4; Chinati Mountains, 4: Davis Mountains, G; Fort Davis, 

10; Ingram, 1: Kerrville, 1: Mason, 30; Paisano, 13; Turtle Creek, 

Kerr County, 17 : Waring. 1!. 


(PI. IV, fig. 3.) 

Peromirscits spicilegus Allen, Bull Am. Mus. Nat. Hist.. N. Y., IX, pp. 50-51, 
March 15, 1897. 

Type locality. — Mineral San Sebastian, Mascota, Jalisco, Mexico. 

Geographic distribution. — Western slopes of the Sierra Madre of 
Mexico from southern Sonora south to southern Jalisco. 

Characters. — Somewhat similar to rowleyi. but size larger and 
color richer; prevailing color rich tawny ochraceous, with blackish 
ears in strong contrast; skull similar to those of boylei, rowleyi, etc.. 
but braincase usually more expanded anteriorly forming an incipient 
supraorbital shelf. 

Color. — Unworn pelage: Upperparts rich tawny, sometimes ap- 
proximating ochraceous rufous; dusky and dusky-tipped hairs uni- 
formly distributed throughout upperparts, but only slightly modify- 
ing the predominating tawny, sometimes slightly concentrated on 
dorsum, forming a poorly defined stripe of blackish ; sides like back, 
lateral line rather broad but not strongly contrasted: a black or 
nearly black orbital ring slightly extended posteriorly into a grizzled 
area between the eye and the base of the ear; ears dusky, very nar- 
rowly or not at all edged with yellowish white; tufts of partly con- 
cealed soft black hairs at the anterior bases of the ears: feet white; 


dusky of hind leg extending to and slightly beyond metatarsal joint; 
underparts creamy white usually with a grayish cast caused by the 
slaty undercolor; a large tawny pectoral spot frequently present; tail 
blackish brown above, white below, the rather coarse ambulations 
usually obvious. Worn pelage: More similar to unworn pelage than 
usual in the genus; upperparts rather duller, more nearly ochraceous 
bull', with dusky mixture minimized or changed to pale brownish 
which appears in general effect like fine vermiculation ; middle of 
back often nearly cinnamon. Adolescent pelage: General effect of 
upperparts nearly sepia with a strong tinge of fawn; lateral line of 
pale ochraceous buff obvious. 

Skull. — Size about as in boylei; braincase rather more flattened 
anteriorly; supraorbital border usually sharp-angled from parieto- 
frontal suture to lachrymal expansion, almost forming a shelf; pala- 
tine slits laterally expanded; interpterygoid fossa relatively wide; 
audital bullae rather small. 

Measurements. — Average of 8 adult topotypes: Total length. 198 
(189-210) ; tail vertebra?, 101, (95-108) ; hind foot, 28.4 (23-25) ; ear 
from notch (dry), 16.3 (15.4-17.3). 

Type specimen. — No. fflf American Museum of Natural History, 
Xew York. S adult. Dec. 2, 1893. Audley C. Buller. Skin in 
fair condition; feet and tail somewhat twisted; pelage smooth and 
clean. Skull practically perfect. 

Remarks. — P. h. spicilegus and its near relatives levlpes. a&tecus, 
etc., are among the most common of Mexican mice. As members of a 
group they are quite easily recognizable, although it is rather difficult 
to formulate a set of characters peculiar to them, and the distinguish- 
ing of different forms within the group is extremely perplexing. 
/'. spicilegus is fairly well restricted to the mountains of western 
Mexico, although within this range variations occur that more or 
less definitely approach rowleyi, levipes, simulus, or evides. Its 
bright tawny color, blackish ears, etc., distinguish it from rowleyi; 
its smaller audital bulla 1 and flattened supraorbital border distinguish 
it from most specimens of levipes; its larger teeth and longer nasals 
from simulus; and its smaller teeth and less extensively duskj' hind 
feet from evides. There is much local variation throughout the 
group, and although the forms mentioned above are fairly well 
marked, the great majority of specimens examined combine the char- 
acters of tAvo or more of them and have been referred to the ones 
they resemble most closely. 

Specimens examined. — Total number 232. from localities as follows: 

Chihuahua: Sierra Madre, 65 miles east of Batopilas, T: Sierra Madre, 

near Guadalupe y Calvo, 5. • 
Colima: Hacienda San Antonio, 5. 
Durango: Chacala, 10; Coyotes, 12; El Salto, 11 ; Iluasamota, 2. 


Jalisco: Aiueca, IT; Arroyo de Gabalan, 3; Barranca Ibarra, (ap- 
proaching evides) ; Bolanos, 1<>: Estancia Jalisco, 1; Etzatlan, 13; 
Jaeala, 2; La Cienega, 4; La Laguna, 8; La Laja, •"»: Mascota, 1; 
Sal si Puedes, 1: San Sebastian, 23: Sierra de Juanacatlan, 5 ; 
Talpa, 3: Wakenakili Mountains, 13. 

Sinaloa: Plomosas, 6 (approaching evides ) ; Sierra de Choix, "><> miles 
northeast of Choix, 14. 

Sonora: Mountains near Alamos, IS. 

Tepic: Jalisco, 2: Pedro Pablo, 1; Santa Teresa, lo (approaching simu- 

Zacatecas: Monte Escobedo. 2: Plateado, 4; Sierra Madre, 10. 

(PI. IV. fig. 4.) 

Peromyscus spicilegus simulus Osgood, Proc. Biol. Soc. Wash., XVII, pp. (i4-fi. r >. 
Mar. 21, 1904. 

Type locality. — San Bias, Tepic. Mexico. 

Geographic distribution. — Lowlands of the west coast of Mexico. 
in Sinaloa and Tepic. 

Characters. — Similar to spicilegus, but smaller and averaging paler; 
nasals shorter; teeth much smaller. 

Color. — Almost as in spicilegus, but averaging slightly paler, as 
indicated by a few specimens in new pelage that are more nearly 
ochraceous buff than tawny; tail in some specimens blackish all 
around, not sharply bicolor; pectoral spot frequently present. 

Skull. — Somewhat similar to that of spicilegus, but smaller and. 
more angular; nasals and rostral part of skull decidedly shorter: 
parietal narrower and less shelf like; premaxilla? not exceeding 
nasals; zygomata relatively heavy and squared anteriorly; molar 
teeth very small ; bony palate short. 

Measurements. — Average of three adult topotypes: Total length. 
208; tail vertebrae, 111 ; hind foot, 23; ear from notch (dry), 15. 

Type specimen. — Xo. 88088 XT. S. National Museum. Biological 
Survey Collection. $ adult. Apr. 18, 1897. E. W. Nelson. Skin 
in good condkion. Skull with last right upper molar missing: 
otherwise perfect. 

Remarks. — This is a well-marked form, a coast representative of 
the mountain animal spicilegus. Specimens from Rosario and near 
Mazatlan are in nearly unworn pelage and perhaps represent the 
extreme of the form, in which the color is somewhat paler than in 
spicilegus. The type of simulus. which was selected with particular 
reference to its cranial characters, is somewhat darker and nearly 
the same color as spicilegus. It may therefore be regarded as slightly 

Specimens examined. — Total number 45. from localities as follows: 

Sinaloa: Escuinapa, 20; near Mazatlan, 6. 
Tepic: Navarrete, 3; Rosario, 10: San Bias, 6. 



Peromyscus madrensis Merriam, Proc. Biol. Soc. Wash., XII, p. l<>, Jan. 27, L898. 

Type locality. — Maria Madre Island, Tres Marias Islands, Mexico. 

Geographic distribution. — Confined to the Tres Marias Islands. 

Character*. — Similar to P. b. spicilegus, but averaging larger and 
paler; ears averaging slightly smaller. 

Color. — Worn pelage: Upperparts chiefly dull ochraceous buff 
more or less k peppered ' and vermiculated with brownish cinnamon, 
the latter most abundant in the middle of the back; lateral line 
rather indefinite, nearly clear ochraceous buff; ears dusky brownish; 
narrow orbital ring and spot at base of whiskers blackish; under- 
pays creamy or yellowish white, often with a prominent ochraceous 
buff pectoral spot; feet dull white, tarsal joint dusky; tail very in- 
distinctly bicolor or almost unicolor, in some specimens dusky above 
and dull whitish below, in others nearly uniform dusky all around 
except proximally where it is always somewhat paler below. 

Skull. — Practically as in spicilegus, but averaging quite decidedly 
larger; skull in general rather more elongate; audita! bulla 1 and 
molar teeth actually about as in spicilegus, relatively smaller. 

Measurements. — Average of 12 adult topotypes: Total length, 224: 
tail vertebra 1 , 120; hind foot, 26; ear from notch (dry), 15.6 (14.7- 

Type specimen. — No. 89223 U. S. National Museum, Biological 
Survey Collection. $ adult. May 18, 1897. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — Although this is a well-marked form, it seems best to 
treat it, as well as its near relative spicilegus, as a subspecies of 
boylei. Individual variation in madrensis and spicilegus practically 
covers the difference between them. Skulls from Maria Cleofa and 
Maria Magdalena are somewhat larger than those from Maria Madre 
and one might almost consider the Maria Madre ones as intermedia- 
ates. Certain of the Maria Madre skulls are exactly like skulls of 
spicilegus from the mainland. 

The series from the islands are in rather worn pelage, and when 
compared with unworn specimens of spicilegus appear very pale, but 
are only slightly paler than similarly worn examples of spicilegus. 

Specimen* examined'. Total number 18, from localities as follows: 

Mexico: Maria Cleofa Island. 3; Maria Madre Island, 14; Maria Mag- 
dalena Island, 1. 


Peromyscus spicilegus evides Osgood, Proc. Biol. Soc. Wash., XVII. p. 04, Mar. 
21, 1904. 

Type locality. — Juquila, Oaxaca, Mexico. 


BOYLE] (lliliri' -LKVIl'KS. 153 

(Geographic distribution. — Western Mexico at lower altitudes than 
P. I>. spicilegus; known from localities in the States of Guerrero, 
Oaxaca, and Michoacan. 

Characters. — Color as in spicilegus, except upper side of hind foot, 
which usually has a wedge-shaped dusky area extending from the 
leg across the tarsal joint nearly to the base of the toes; skull and 
teeth decidedly larger and heavier. 

Color. — Upperparts tawny ochraceous slightly mixed with dusky, 
this slightly or scarcely concentrated medially; a narrow black orbital 
ring and spot at base of whiskers; underparts creamy white usually 
with a tawny pectoral spot; tail blackish above, white below; fore- 
arm sooty to wrist, hands white; tarsal joint and proximal half of 
hind foot usually dusky except on sides. 

Skull. — Similar to that of spicilegus but larger and heavier; supra- 
orbital border, quite shelf like; molar teeth larger and heavier; also 
similar to that of aztecus, but averaging slightly shorter and broader. 

Measurements. — Average of 5 topotypes: Total length, 208; tail 
vertebra^ 111; hind foot, 23; ear from notch (dry). 13.6 (12.6-14.5). 
Of 10 adults from Los Reyes, Michoacan: 222 (212-230); 112 
(105-122); 23.6 (23-25). 

Type specimen. — No. 7142G IT. S. National Museum, Biological 
Survey Collection. $ yg. adult. Feb. 28, 1895. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — This form appears to be the western representative of 
aztecus, from which it differs chiefly in its paler color. Although no 
unquestionable, intergrades between aztecus and evides are at hand, 
nor any specimens from intermediate localities, the difference between 
the two is so slight and so nearly bridged by individual variation, 
that the existence of intergrades is scarcely to be doubted. Inter- 
grades between e rides and spicilegus have been examined from Plo- 
mosas. Sinaloa and Barranca Ibarra, Jalisco, and even from San 
Sebastian, the type locality of spicilegus. 

Specimens examined. — Total number 47. from localities as follows: 

Guerrero: Omilteine, 11. 
Michoacan: Los If eyes. 31. 
Oaxaca: Juquila, 5. 

(PI. IV. fig. 2.) 

Peromyscus levipes Merriam, Proc. Biol. Soc. Wash.. XII. pp. 123-124, Apr. 

30, 1898. 
Peromyscus beatae Thomas, Ann. & Mag. Nat. Hist.. London, Ser. T, XI. pp. 
485-486, May, 1903.— Mount Orizaba. Mexico. 
Type locality. — Mount Malinche, Tlaxcala, Mexico. 
Geographic distribution. — Eastern and southwestern Mexico and 
western Guatemala, chiefly in mountainous regions from • central 
Nuevo Leon south through San Luis Potosi. Hidalgo. Veracruz, 


etc., to southern Oaxaca; reappearing in the highlands of Chiapas 

and western Guatemala. 

Characters. — Similar to spicilegus, but somewhat Larger and darker 
colored; dusky mixture in upperparts more copious; pelage usually 
longer and softer; skull usually broader; supraorbital border not so 
sharp-angled; audital bullae larger. Similar to aztecus, but color 
much duller and more dusky. 

( 'olor. — Unworn pelage : Ground color of upperparts varying from 
rich ochraceous bun" to tawny always strongly modified by dusky, 
producing a general effect that varies from russet to Prout brown ; 
sides with tawny rather predominating; lateral line not sharply 
marked; back with dusky usually predominating, sometimes forming 
a blackish diffuse stripe, often taking the form of close lines; orbital 
ling blackish, slightly produced posteriorly toward a grizzled area 
between the eye and the base of the ear; ears dusky, scarcely edged 
with whitish ; a tuft of soft blackish slate hairs at the anterior base 
of the ear; underparts creamy white, never thoroughly concealing the 
slaty undercolor: a pectoral spot sometimes present; feet white, tarsal 
joint sharply marked with dusky; tail bicolor, brownish dusky above, 
white below, under side sometimes flecked with dusky. Worn pelage: 
General effect of sides and upperparts bright cinnamon or ochraceous 
buff to tawny usually with a darker middorsal area of russet or Prout 
brown; dusky markings reduced throughout and more brownish than 

Skull. — Quite variable; usually larger, shorter, broader, and with 
larger audital bullae and molar teeth than in spicilegus; supraorbital 
border not so sharp-angled and seldom showing much tendency to the 
development of a shelf; infraorbital notch slight or scarcely evident. 
Similar to that of aztecus but usually shorter and broader; audital 
bulla^ averaging larger; supraorbital border not so sharp-angled. 

Measurements. — Type and 1 topotype, respectively: Total length, 
200, 184; tail vertebrae, 102, 93; hind foot, 2-3.5: 22. Two adults from 
Maltrata, Veracruz: 212, 192; 114, 102; 25, 22. Average of ten 
adults from Encarnacion, Hidalgo: 208 (198-234) ; 108 (97-123) ; 24 
(23-25) ; ear from notch (dry) 16.2 (15.6-16.7). Average of seven 
adults from Zunil, Guatemala, 212 (204-227) ; 110 (103-123) ; 28.1) 

Type specimen. — No. 53673 U. S. National Museum. Biological 
Survey Collection. $ adult, old. May 12, 1893. E. W. Nelson 
and E. A. Goldman. Specimen in good condition. 

Remarks. — This is a common and widely distributed form through- 
out most of the mountainous parts of eastern, central, and southern 
Mexico and Guatemala. Although doubtless many mountain colo- 
nies are quite isolated, there is comparatively little local variation. 
Thus, those of the highlands of Chiapas and Guatemala are sepa- 
rated from those of more northern localities bv the low and relatively 


arid region of the Isthmus of Tehuantepec. Vet series from Guate- 
mala do not differ from comparable scries from Hidalgo, for exam- 
ple; or if there is any difference between selected specimens it is no 
greater and is usually less than individual variation in each of the 
scries concerned. Individual variation is relatively great, especially 
in size and cranial characters. The. size of the audital bulla 1 , while 
averaging greater than in spicilegus, aztecus, etc.. is extremely varia- 
ble, and often each specimen of a considerable series from one local- 
ity has slightly peculiar bulla?. The size of the molar teeth also varies. 
and in some cases to such an extent that suspicion arises that two dis- 
tinct species are being confused. Nevertheless, it does not seem pos- 
sible to prove this. Color variation runs from specimens as bright 
as spicilegus to others almost as dark as lepturus. 

Certain individuals in almost every series can scarcely be dupli- 
cated elsewhere, and even the type of levipes is not exactly like any 
of several topotypes. Under these circumstances, the only logical 
course seems to be to unite all of one general type under the name 
levipes. Specimens from Nuevo Leon average rather smaller than 
usual and show much resemblance to spicilegus in color, but they may 
he exactly matched among specimens from the general vicinity of the 
type locality. At other localities the average size may be large, but 
this again is nearly or quite covered by individual variation. '/'. 
Uc(it(ic\ described from Mount Orizaba, relatively very near Mount 
Malinche, is an undoubted synonym, being well within the range of 
variation ordinarily found in the boylei group. Mr. Thomas had no 
specimens of levipes and attempted no comparisons with it at the 
time he proposed the name beatae. 

Specimens examined: Total number 402. from localities as follows: 

Chiapas: Canjob, 4; Comitan, 16; mountains near Comitan, 3; Valley of 

Comitan, 18; San Cristobal, 22: Teopisca (20 in. southeast), G. 
Guatemala: Calel, <">; Hacienda Chancol, 21: Todos Santos. 4: Volcan 

Santa Maria, 18; Zunil, 23. 
Guerrero: Ayusinapa, 4 (approaching spicilegus?) : mountains near Chil- 

pancingo, 38. 
Hidalgo: El Chieo, 17; Encarnacion, 25; Pinal tie Amoles, 10; Heal del 

Monte. 7: Tulancingo, 4. 
Jalisco: Ocotlan, 1 : Zapotlan, 1. 
Mexico: Tlalpam, 1. 
Michoacan: Patzcuaro. 1. 

Morelos: Cuernavaca, 1 : Tetela del Volcan, 3 (aberrant). 
Nuevo Leon: Cerro de la Silla, 18; Monterey, 37 i aberrant). 
Oaxaca: Cerro San Felipe. 4: Mount Zempoaltepec, 3; mountains west 

of Oaxaca, 8; mountains near Ozolotepec, 11 : Reyes, 20; San Miguel, 

5; Tamazulapam, 1. 
Puebla: Atlixco, 2; San Martin, 1 ; Tochimilco, 4 (aberrant). 
San Luis Potosi: Villar, 11. 
Tlaxcala: Mount Malinche, 4. 
Veracruz: Maltrata, 6; Orizaba. 2; Perote. 4; Xometla Camp, .Mount 

Orizaba, 6 ; Xuchil, 6. 


(PI. IV. flg. 5.) 

FFcsperomys aztccus Saussure, Rev. <*t Mag. de Zool., Paris, XII, pp. 105-106, 

pi. IX, Qg. 4, Mar., I860. 
P\eromyscv8] astecus Thomas, Ann. & Mag. Nat. Hist.. s<-r. <;, xi\'. p. :;(;:,. 

Nov.. I sill. 

Type locality. — Mexico; probably the vicinity of Mirador, Vera- 

Geographic distribution. — Lower austral zone (and possibly part 
of humid tropical) of parts of the States of Veracruz and Puebla. 

Characters. — Size medium (hind foot 23-20) , slightly larger than 
levipes, smaller than mexicanus and oaxacensis; tail about equal to 
head and body, rather coarsely hairy and usually decidedly bicolor; 
ears moderate, very thinly haired; color very rich, chiefly deep 
tawny; most similar to P. b. evides but size slightly larger; ears 
larger, and color richer; skull with supraorbital border sharp-angled 
but not definitely beaded. 

Color. — Upperparts deep rich tawny with light mixture of blackish 
on sides and heavier on dorsum forming a poorly defined blackish 
dorsal area; black orbital ring and spot at base of whiskers sharply 
defined against tawny check; toes and distal part of feet white; front 
side of forearm tawny and dusky nearly or quite to wrist; outer side 
of hind leg, tarsal joint, and median proximal half of upper side of 
hind foot blackish brown; ears dusky without definite pale edgings, 
a tuft of partly concealed blackish hairs at their anterior bases; tail 
blackish brown above, white or white lightly sprinkled with brownish 
below; underparts creamy white, occasionally with a small tawny 
pectoral spot. Worn pelage: Very similar to unworn pelage but 
slightly duller and with tawny still more largely predominating over 
the dusky mixture; dorsum but little different from sides. 

Skull. — Size medium; teeth relatively large; braincase rather deep 
and slightly elongate; interparietal large; supraorbital border sharp- 
angled, but not beaded; zygomata quite distinctly notched anteri- 
orly; audital bulla 1 rather small; interpterygoid fossa rather wide 
and expanded anteriorly. Most like that of e rides, but slightly larger 
and more angular; smaller, with relatively larger teeth than in 
oaxacensis or mexicanus; braincase narrower, supraorbital border 
more sharply angled, and audital bullae smaller than in levipes. 

Measurements. — Average of 5 adults from Mirador. Veracruz: 
Total length, 229 (215-238) ; tail vertebra 1 , 113 (107-121) ; hind foot, 
24.5 (24-20) : ear from notch (dry), 15.2 (14.5-16). 

Type specimen. — In the original description (1. c. p. 100, foot- 
note). Saussure stated that he had 3 specimens and naturally at that 
date he did not specify one of them as the type. At least two of 


these specimens now exist, one a mounted specimen accompanied by 
a skull in the Geneva Museum, and the other a skin in rather poor 
condition in the U. S. National Museum. The figure of the molar 
teeth published by Saussure doubtless represents the Geneva speci- 
men, since this has the only skull known, to have been preserved. 
Therefore if a type must now be selected, it should be the Geneva 
specimen. The specimen in the U. S. National Museum (No. 3926) 
is perhaps of greater value for comparison, as it is a skin and, not 
having been much exposed to light, shows nearly its original colors. 
It is slit down the middle of the back and only the head and legs 
are stuffed with cotton. Some hair is gone from the throat, the left 
ear is imperfect, and the distal half of the tail absent; otherwise it 
is well preserved and agrees in every respect with recently collected 
specimens from Mirador. Veracruz, which, in the lack of exact 
knowledge, may be assumed to be the type locality, as it is certain 
that some at least of Saussure's specimens were taken near there. 

Remarks. — P. l>. aztecus is characterized chiefly by its very rich 
tawny color, and by this may be readily distinguished from most 
other species of eastern Mexico. P. oaxacensis approximates this 
richness of color, but is considerably larger and occurs at greater 
elevations. P. me.eicanus is also larger and has relatively small teeth, 
less tawny color, and irregularly marked tail. P. b. levipes is more 
nearly the size of aztecus, but has smaller teeth, larger audital bulla 1 , 
and less tawny color. 

It is with some reluctance that aztecus is included among the sub- 
species of boylei, but no break in the continuous series of definable 
forms seems discoverable. From spicilegus to evides is but a short 
step, and from evides to aztecus but another, and each is almost or 
quite bridged by individual variation. Although spicilegus is be- 
lieved to intergrade with levipes, there is no evidence that aztecus 
does so, and it would not be surprising to find both aztecus and 
levipes at one locality. 

The applicability of Saussure's name to this form is scarcely to be 
doubted, for even if the specimens still extant are disregarded, the 
original description is so accurate and complete as to be conclusive. 
The combination of rich tawny color and the extension of dusky on 
the hind feet has not been found in any other species of eastern 
Mexico. Both these characters are emphasized by Saussure, as shown 
from the following extracts from his description : 

Le pied blancMtre, avec le premier tiers bruii-gris en dcssus. * * * 
souvent aussi le pied posterieur est gris-brun jusqu'aux doigis et niele de poils 
blancs * * * par ses flancs qui sont d'un ferrugineux cannelle ainsi que la 
face externe des pattes antcrieures. Cette couleur est tr£s-prononc6e. 

" 1 am indebted to Dr. Merriam for notes and a careful description of tbis 
specimen, wbicb was critically examined by bim sonic years ago. 


Specimens examined. — Total number 18, from localities as follows: 
Puebla: Huachinango, (». 
Veracruz: Jalapa, 1! ; 'Mexico,' 1; Mirador, 9. 

(PI. Ill, fig. 5.) 

Peromyscus oaxacensis Merriam, Proc. Biol. Soc. Wash., XII, p. 1'2'2, Apr. 30, 
Type locality. — Cerro San Felipe. Oaxaca, Mexico. Altitude 10,300 


Geographic distribution. — High altitudes in southern Mexico, 
chiefly in the State of Oaxaca ; reappearing in the mountains of 
central Chiapas. 

Characters. — Size rather large (hind foot 25-29); tail decidedly 
longer than head and body, well haired and evenly bicolor; sole of 
hind foot, except plantar tubercles, hairy; ears relatively small; 
color chiefly rich tawny ; similar in general characters to P. b. aztecus, 
but larger and longer-tailed; skull heavier. 

Color. — Upperparts rich tawny mixed with black; middle of back 
more blackish, sides and shoulders more tawny ; sides of face tawny 
with scarcely a suggestion of grayish ; orbital ring and spot at base 
of whiskers black; sides of nose buff'y; ears very thinly haired, 
scarcely or not at all edged with whitish; feet white, tarsal joint 
dusky: underparts creamy "white; tail evenly bicolor, blackish above, 
white below. Worn pelage: General effect of upperparts bright, 
rich tawny shading to cinnamon rufous in middle of back and but 
little modified by mixture of dusky. Adolescent pelage: Upperparts 
mixed pale tawny and dusky, producing a general effect approaching 
bistre and sepia. Color in all pelages almost exactly as in P. b. 

Sl-all. — Similar to that of P. b. aztecus. but averaging larger and 
heavier: cheek teeth larger: audital bullae actually slightly larger, 
relatively about same size; palatine slits larger; supraorbital border 
sharp-angled but not beaded; general characters about as in hylo- 
cetes, but audital bullae slightly smaller. 

Measurements. — Type: Total length 242; tail vertebrae 122; hind 
foot 27. Average of 6 adults from San Cristobal, Chiapas: Total 
length 240 (241-260); tail vertebrae 127 (120-135); hind foot 27; 
ear from notch (dry) 16.7 (15.8-17.5). 

Type specimen. — No. 68426 U. S. National Museum, Biological 
Survey Collection. $ adult. Sept. 1, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — Individual variation so nearly bridges the difference 
between oaxacensis and aztecus that very little objection could be 
made if oaxacensis were included with aztecus as a subspecies of the 
boylei series. In its rich tawny color and all general characters it 


is closely similar to aztecus, differing merely in larger size and longer 
tail. It inhabits much more elevated regions than aztecus and occurs 
at the same localities with another member of the boylei series. 
levipes, from which it may be distinguished both by external and by 
cranial characters. Possibly here is another example of two sub- 
species of the same group occurring together, for levipes appears to 
intergrade with spicilegus, spicilegus with evides and aztecus. and 
quite probably aztecus with oajcacensis. However, until the evidence 
is more complete, it is perhaps best to consider oaxacensis as distinct. 
In some conditions of pelage, mexicanus may show considerable 
resemblance to oaxacensis, but the latter is always distinguishable by 
its more hairy, sharply and evenly bicolor tail. 
Specimen* examined. — Total number 09, from localities as follows: 
Chiapas: Conritan Valley. 5; Pinabete, 12: San Cristobal, 24. 
Oaxaca: Cerro San Felipe, 2: Comaltepec, 1: Oaxaca (15 in. west), (J; 
Keyes, 1!>. 


i PI. III. tig. 8.) 

Peromyscus hylocetes Merriani. Proc. Biol. Sue. Wash., XII. p. 124, Apr. 

30. ISDN. 

Type locality. — Patzcuaro, Michoacan, Mexico. Altitude 7.000 

Geographic distribution. — Mountainous parts of Michoacan and 
southern Jalisco; east to mountains near the Valley of Mexico. 

Characters. — Size medium; tail rather short, usually shorter than 
head and body, well clothed with hair and sharply bicolor; color 
rather dark; most similar to eoides and oaxacensis, but differing from 
both in relatively shorter tail and larger audital bullae. 

Color. — Unworn pelage: Upperparts pale ochraceous buff, becom- 
ing tawny on sides, heavily mixed with blackish, forming a more or 
less definite blackish dorsal stripe; a narrow lateral line nearly clear 
tawny, widening somewhat on lower cheeks; nose and post orbital 
region slightly grayish; orbital ring and spot at base of whiskers 
sharply blackish; ears thinly clothed with brownish hairs, scarcely 
or not at all edged with whitish, soft blackish partly concealed hairs 
at anterior bases; underparts creamy white, usually modified by 
blackish slate undercolor; feet chiefly white, dtisky extending nearly 
to carpal joint and over tarsal joint sometimes halfway to the end of 
the hind foot; tail sharply bicolor, blackish above, white below. 
Worn pelage: General effect of upperparts cinnamon to russet; dor- 
sal stripe not well differentiated, but dark undercolor showing 
throughout upperparts; lateral line scarcely distinct; otherwise as in 
unworn pelage. 


skull. — Similar in general form to those of aztecus and oaxacensis; 
audita] bullae slightly inflated, larger than in evides or oaxacensis, 
but smaller than in difficilis or melanophrys ; palatine slits rather 
large; interpterygoid fossa somewhat widened anteriorly; no supra- 
orbital bead, but frontals rather wide and supraorbital border de- 
cidedly sharp-angled, sometimes forming a slight shelf; nasals rather 
narrow and depressed anteriorly; premaxillae somewhat expanded 

Measurements. — Type: Total length, 238; tail vertebra', 114; hind 
foot, 25. Average of 6 adults from Mount Tancitaro, Michoacan: 
Total length, 227 (220-237) ; tail vertebrae, 113 (106-117) ; hind foot, 
26.1 (25-27) ; ear from notch (dry), 18 (17.5-18.5). 

Type specimen. — Xo. 50423 U. S. National Museum, Biological 
Survey Collection. $ adult, July 27, 1892. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — This species is evidently a member of the boylei series, 
but appears to be distinct, although it approaches aztecus and evides 
very closely. Its slightly shorter tail, more blackish color and 
larger audita! bullae are the chief characters distinguishing it from 
these forms. It averages somewhat larger throughout and the skull 
is usually heavier; but there is some variation in size, and skulls are 
found practically identical with those of evides, save that the audita] 
bullae are slightly larger. It closely resembles oaxacensis in color 
and general characters, but is easily separated from that species 
by its shorter tail. From levipes it is distinguished by its sharp- 
angled supraorbital border and less abruptly constricted frontals. 

Specimens . examined. — Total number 74, from localities as 
follows : 

Jalisco: Sierra Nevada de Coliwa, 13. 

Mexico: Amecameca, 3. 

Michoacan: Mount Tancitaro, 17: Patamban, 37: Patzcuaro, 3. 

Morelos: Iluitzilac, 1. 

Key to subspecies of Peromyscus pectoralis. 

Size larger; hind foot 21—23 ; tail relatively shorter, averaging less than 100. 

Western Texas and Mexico near the Rio Grande P. p. laceicmue 

Size smaller: hind foot 20-22; tail averaging more than 100. North Central Mexico. 
Size smaller; color paler; no pectoral spot; tarsal joint white, 

P. p. eremicoides 

Size larger; color darker: usually with a buffy pectoral spot: tarsal joint 

usually with at least a trace of dusky /'. pectoralis 


Peromyscus attwateri pectoralis Osgood, Proc. Biol. Soc. Wash., XVII, pp. 
59-60, March 21. 1904. 

Type locality. — Jalpan, Queretaro, Mexico. 

Geographic distribution. — Known from scattered localities in the 

Sonoran zone of eastern and central Mexico, from central Nuevo 




Leon south to Queretaro, and thence west through southern San Luis 
Potosi and (probably) Guanajuato to eastern Jalisco and southern 

Characters. — Size and proportions about as in P. eremicus; color 
darker and more vinaceous; tail more coarsely annulated and more 
hairy, sole of hind foot somewhat hairy on proximal third; skull and 
teeth widely different. Closely similar in general characters to P. 
rowleyi and P. levipes, but with relatively longer tail and always 

Fin. 5. — Distribution of Peromyscus pectoralis, P. megalops, P. furvus, and 

/'. guatemalensis. 

distinguishable by smaller size, particularly by smaller skull and 
molar teeth. 

Color. — Unworn pelage: Ground color of upperparts pale ochra- 
ceous buff, thickly sprinkled with dusky, producing a general effect 
of dark wood brown ; sides of head behind eyes slightly grayish ; a 
narrow dusky orbital ring; underparts white, pectoral region usually 
strongly buffy ochraceous; ears brownish dusky, narrowly edged with 
whitish, no markings about base; feet white, tarsal joint usually 
with little or no extension of dusky from leg; tail variable, dusky 

66268— No. 28—09 11 


brownish above and white or often with a considerable sprinkling of 
dusky below. Worn pelage: Upperparts pale ochraceous butt', 
heavily mixed with dusky cinnamon, producing an effect of pale 
russet ; sides of head usually showing more grayish than in unworn 
pelage; otherwise not peculiar. 

Skull. — Most similar to that of rowleyi, but smaller throughout; 
rostrum relatively somewhat broader and heavier: braincase less 
vaulted; molar teeth decidedly smaller. Somewhat similar to that 
of levipes, but smaller; lacrymal '-egion less swollen; premaxilhe 
usually ending slightly beyond the even nasals; interparietal rela- 
tively large. 

Measurements. — Type: Total length, 210; tail vertebra 1 . 114: hind 
foot. 22. Average of 10 adults from Villar. San Luis Potosi : 201 
(105-200): 110.7 (102-115); 21 (20-22); ear from notch (dry), 

15.5 (15.4-17.2). 

Type specimen. — No. 81236 U. S. National Museum. Biological 
Survey Collection. $ adult. Aug. 30, 1890. E. W. Nelson and E. 
A. Goldman. Specimen in good condition. 

Remarks. — This is the representative of a small group of sub- 
species any of which in certain pelages shows considerable superficial 
resemblance to P. ere miens or some of its forms. That none of them 
are closely related to eremicus is easily demonstrated by a compari- 
son of the molar teeth. They are really nearest to P. ooylei and its 
subspecies, from which they may be distinguished by smaller size, 
relatively longer tails, and certain cranial characters. The absence 
of dusky markings on the tarsal joint, which is characteristic of the 
other forms eremicoides and laoeianus, is not absolutely constant in 
pectoral'*. The majority of specimens, however, show no trace of 
such marking. The name pectoralis is by accident the first one ap- 
plied to a member of this group, having been cited as a subspecies of 
attwateri, the type -of which proved to be another species. The form 
pectoralis. as its name implies, is characterized by the presence of a 
buffy pectoral spot. When this is absent or not well developed, as is 
sometimes the case, the form may be distinguished from eremicoides 
and laceianus by its darker color. 

Specimens examined. — Total number 02, from localities as follows: 

Jalisco: Atemajac, 2: Barranca Ibarra, 1 : Bolauos, 1; Colotlan, 1. 

Nuevo Leon: Cerro tie la Silla, 2; Monterey, 10. 

Queretaro: Jalpan, 5. 

San Luis Potosi: Jesus Maria, 1 : Villar, 10. 

Tamaulipas: Victoria, 26. 

Zacatecas: Hacienda San Juan Capistrano, 2: Monte Escobedo. 1. 

«Cf. Bailey, Proc. Biol. Soc. Wash., XIX, pp. 57-58, 1908. 



(PI. IV, tig. T.l 

Peromyscus attwateri eremicoides Osgood. Proc. Biol. Soc. Wash., XVII, p. 60, 
March 21, 1904. 

Type locality. — Mapimi, Durango, Mexico. 

Geographic distribution. — North central Mexico, chiefly in the 
States of Durango, Coahuila. and Chihuahua: north to southern 

Characters. — Similar to P. pectoralis, but smaller and paler; color 
nearly as in P. p. laceianus and often much as in /'. eremicus; ears 
quite small; skull small and light; audital bullae very small: soles of 
hind feet usually slightly hairy proximally but sometimes naked, 
at least medially. 

Color. — Upperparts mixed pinkish bull' and dusky, producing the 
general effect of pale broccoli brown; lateral line pinkish bull': facia! 
region between eye and ear grayish; underparts pure creamy white 
without trace of pectoral spot : feet white, no dusky marking on 
tarsal joint; tail pale grayish dusky above, white below. 

Skull. — Similar to that of pectoralis but decidedly smaller; audital 
bullae very small: nasals short and only slightly or not at all ex- 
ceeded by the ascending branches of the premaxilla 1 ; rostrum slightly 
depressed; interorbital constriction relatively wide. 

Measurements. — Type and one topotype: Total length, ISO, 195; 
tail vertebrae, 10:2, 111; hind foot, 20, 21; ear from notch (dry), 
14.3, 16.6. 

Type specimen. — No. 57729 U. S. National Museum. Biological 
Survey Collection. S adult, Dec. 15, 1893. E. A. Goldman. 
Specimen in good condition. 

Remarks. — This form is readily distinguishable from pectoralis 
by its small size, paler color, and pure white underparts. From 
laceianus it differs chiefly in smaller size. Its resemblance to erem- 
icus, particularly when in worn or immature pelage, i- remarkable. 
The external characters distinguishing it from eremicus arc smaller 
ears, slightly more hairy tail, and white tarsal joints. But these are 
sometimes difficult to appreciate, as the tail in eremicus is often quite 
hairy, and the dusky on the tarsal joint sometimes so little developed 
as to be scarcely apparent. However, the molar enamel pattern, ex- 
cept in extremely worn teeth, is always diagnostic, eremicoides having 
the small accessory cusps and eremicus being without them. Speci- 
mens from the type locality of eremicoides and a few neighboring 
localities are well characterized by their small size, but many from 
outlying localities, though referable to eremicoides, are larger and 
approach laceianus or pectoralis. Three specimens from Fori Una- 


chuca, Ariz., seem indistinguishable from typical eremicoides. Fur- 
ther material from this region is much needed. 

Specimens examined. — Total number 56, from localities as follows: 

Arizona: Fort Huachuca, 3. 

Chihuahua: Chihuahua, 3; Santa Eulalia, 8. 

Coahuila: Carneros, .'> : Jaral, '2 ; Jimulco, 4; Saltillo, 10; Sierra Encar- 

aacion, 1. 
Durango: Inde, <3; Mapimi, 12. 
Nuevo Leon: Santa Catarina, 9. 
Tamaulipas: Janmave Valley, 2 (aberrant) ; Miqninuana, 3. 


Peromyscus attwateri Bailey, N. Am. Fauna No. 25, i>. 100, 1!)05 — not of Allen. 
Peromyscus pectoralis laceianus Bailey, Proc. Biol. Soc. Wash., XIX, pp. 57-58, 
May 1, 1906. 

Type locality. — Lacey Ranch, near Kerrville, Tex. 

Geographic distribution. — West central Texas, from the vicinity 
of Austin to the Big Bend of the Rio Grande and immediately adja- 
cent parts of Mexico. 

Characters. — Similar to P. p. eremicoides, but larger and with tail 
relatively shorter; somewhat similar to P. b. attwateri but smaller; 
color more grayish; feet and tarsal joint white without dusky mark- 
ing; skull and teeth smaller. 

Color. — Unworn pelage: Similar to eremicoides, but slightly more 
vinaceous; ground color of upperparts pinkish buff with a variable 
mixture of dusky, not especially concentrated on dorsum but quite 
evenly distributed; general effect varying from broccoli brown to 
wood brown; underparts creamy white; no white at bases of ears; 
feet white, tarsal joint not marked with dusky ; tail pale brown above, 
white below. Worn pelage : Dusky of upperparts paler and less 
extensive; predominating color pale ochraceous buff to pinkish buff 
«»• dusky so changed to cinnamon brown shades that the general effect 
of the upperparts is a peculiar shade variously approaching the ecru 
drab, cinnamon, and fawn of Ridgway. 

Skull. — Similar to that of pectoralis; decidedly larger than that 
of eremicoides; rostrum averaging slightly heavier than in either. 
Somewhat like that of attwateri but decidedly smaller; molar teeth 
smaller and weaker; braincase relatively more elongate; interparietal 
relatively larger. 

Measurements. — Type: Total length. 185: tail vertebras, 95; hind 
foot, 23. Average of 6 topotypes: 187 ( 185-192) ; 96 (94-100) ; 22.1 
(22-23) ; ear from notch (dry), 15.8 (15-16.2). 

Type specimen. — No. 97063 U. S. National Museum, Biological 
Survey Collection. $ young adult. May 3, 1899. V. Bailey. Speci- 
men in good condition. 

1909.] TRUE] GROUP — TRUEI. 165 

Remarks. — Of the numerous forms occurring in Texas, this one 
is apt to be confused with ere miens and attwateri only. Dental 
characters readily eliminate eremicus, and the presence of dusky 
markings on the tarsal joints of attwateri suffices to remove it from 
consideration. At first sight laceianus conveys the impression of a 
rather pale grayish individual of attwateri or rowleyi, and its skull 
is sufficiently similar to make it quite certain that its nearest affinity 
is with the boylei group. It occurs at the same localities with att- 
wateri and. like that form, inhabits rocky situations. Slight con- 
fusion of names has resulted through a misapplication of the name 
attwateri (Bailey I. 6'.), but this is now cleared up, and laceianus 
appears to be the only name that has been properly applied to this 

Specimens examined. — Total number 150, from localities as fol- 

Coahuila: Opposite Langtry, Tex., 9; 15 in. southeast of Langtry, Tex., 1; 
Head of Las Vaeas Creek, 1 ; 15 m. east of Las Vacas, 1. 

Texas: Austin, 13; Boerne, 5; Near Camp Verde, 5; Cliisos Mountains, 4; 
Comstock, 0; Davis Mountains. 1; Fort (Mark. 4; Llano. 4; Mouth of 
Devils River, 2; Fort Lancaster, 5; Howard Springs, 2; Ingram, 20; 
Japonica, 9; Near Juno, 2; Kerr County. 24 (Lacey Ranch 8, Turtle 
Creek 16) ; Langtry, 13; Marathon, 1; Mason, 6; East Painted Cave, 
1 ; Pecos River, 55 in. northwest of Comstock, 1 ; Rock Springs, 1 ; 
Samuels, 2 ; San Antonio, 1 ; Sanderson, 1 ; Sheffield, 5. 

Key to subspecies of Peromyscus truei. 

a. Habitat western United States. 

1. Color paler, largely ochraceous buff; ears averaging larger. Chiefly south and east 

of the summit of the Sierra-Cascade Range P. truei 

2. Color darker, largely deep ochraceous. tawny, cinnamon, or russet, often with much 

dusky mixture : ears averaging smaller. California and Oregon, chiefly west of 

the summit of the Sierra-Cascade Range P. t. gilberti 

aa. Habitat Mexico. 

6. Habitat Lower California. 

1. Size larger. Northern /'. t. martirensis 

■2. Size smaller. Southern P. t. lagunae 

66. Habitat Mexico (except Lower California i. 

c. Tail shorter, averaging less than 100; ears slightly larger; color pale. North- 
ern P. truei 

cc. Tail longer, averaging about 110; ears slightly smaller. Central and southern. 

1. Darker P. '• gratus 

2. Paler P. t. gentilis 


(PI. IV, fig. 6; PI. VII, fig. 10.) 

Hesperbmysjruei Shufeldt. Proc. U. S. Nat. Mus., VIII, pp. 407-408, pi. XXI, 

Sept. 1L 1885. 
Hesperomys megalotis Merriam, N. Am. Fauna No. 3, pp. 63-64, pis. III-IV, 

figs. 1-4, Sept. 11, 1890.— Black Tank, Little Colorado Desert. Arizona. 
P[eromyscus] truei Thomas. Ann. & Mag. Nat. Hist., ser. 6, XIV. p. 365, Nov., 

Peromyscus lasius Elliot, Field Col. Mus., Chicago, Zool. Ser., III. pp- 265-266, 

Mar. 8, 1904. — Haunopee Canyon, Pauaniint Mountains. California. 



[NO. 2? 

Peromyscus montipinoris Elliot, supra dt., III. pp. 264-265, Mar. 8, 1904. — Lock- 
wood Valley, Mount Pinos, California. 


m * 





Areas of 

Fie:. C>. — Distribution of Peromyscus tniei and subspecies. 

Type locality. — Fort Wingate, N. Mex. 

Geographic distribution. — Southwestern United States and north- 
ern Mexico from southern California (east of the Sierra and San 

L909.] TRUE] GBOUP TRUEI. 167 

Bernardino ranges), across southern Nevada, southern Utah, Ari- 
zona, to west central New Mexico, and thence south in Mexico at least 
to north central Chihuahua. 

Characters. — Size medium; tail usually about equal to head and 
body (often slightly shorter, occasionally slightly longer) ; pelage 
quite long, lax, and silky; ears very large, about equal in length to 
hind foot ; hind foot usually densely haired from calcaneum to 
proximal plantar tubercle (about proximal two-fifths of foot). 
Similar to P. b. rowleyi but ears larger, pelage usually longer and 
softer, tail more closely haired, ambulations finer and more nearly 
concealed; skull with auclital bulla 1 larger and more orbicular. 
Similar to P. nasutus but size smaller, color brighter, less grayish; 
ears slightly larger; skull usually smaller throughout; audital bullae 
actually and relatively larger. 

Color. — Unworn pelage: Ground color of upperparts ochraceous 
buff' mixed on back and sides with fine dusky lines, the general effect 
variously approaching wood brown, Isabella color, and cinnamon; 
lateral line usually well defined, pure ochraceous buff without dusky 
mixture; sides of face and nose somewhat grayish; a narrow dusky 
orbital ring and slight dusky spot at base of whiskers; ears dusky 
brownish thinly clothed within and without with short grayish white 
hairs; tufts at anterior bases of ears practically same color as sur- 
rounding parts and without any definite white or black; underparts 
creamy white; feet white, tarsal joint slightly dusky, this often 
partly concealed by overlying white hairs; tail slightly bicolor. 
brownish dusky above, white below. Worn pelage: General effect 
of upperparts pale ochraceous buff to pinkish buff mixed with pale 
cinnamon so blended as to modify the general color but little ; lateral 
line scarcely distinct from upper sides; otherwise practically as in 
unworn pelage. Adolescent pelage: Upperparts dull buff strongly 
mixed with fine dusky lines, producing a general effect of broccoli 
brown lightly tinged with buff; lateral line pale ochraceous buff, 
narrow but well-defined; head and face except lower cheeks quite 
decidedly more grayish than rest of upperparts." Young in first 
coat: Upperparts pale drab gray overcast with dusky particularly 
on dorsum. 

Skull. — Size medium (greatest length '26-30) : braincase rather deep 
and somewhat vaulted; zygomata somewhat heavy and squared an- 
teriorly, deeply notched by infraorbital foramen; nasals rather broad 
and flat, abruptly cuneate posteriorly; audital bulla 1 large and 
orbicular; interpterygoid fossa nearly right-angled, the anterior 
angles slightly rounded and indenting palatal shelf. Compared with 

a This is usually caused by the persistence of the preceding pelage for a 
longer period on these parts than elsewhere. 

168 NORTH AMERICAN FAUNA. . [no. 28. 

that of rowleyi, the skull of truei shows many differences, but the 

most obvious and diagnostic is the size of the audital bullae, which 
is nearly double that of rowleyi. Compared with that of nasutus, 
the skull of truei is slightly smaller; braincase narrower and deeper; 
zygomata heavier, more angular anteriorly, and more deeply notched 
by infraorbital foramen; rostrum and nasals shorter; audital bulla- 
always relatively and usually actually larger. 

Measurements. — Average of 10 adult topotypes: Total length, 18G 
(180-195) ; tail vertebra?, 92 (8G-102) ; hind foot, 23; ear from notch 
(dry), 2-2.4 (21.5-21). Of 10 adults from the Manzano Mountains, 
New Mexico: 197 (180-210); 98 (90-106); 22.5 (22-23). Of 10 
adults from the Panamint Mountains, California: 198 (189-210); 
103 (97-112); 23.7 (23-24.5). 

Type specimen. — No. Iff ft U. S. National Museum. $ adult 
(old). Mar. 14, 1885. R. W. Shufeldt. Skin rather poorly formed: 
pelage clean, long, and full; right foreleg and left hind leg missing. 
Skull in good condition; teeth, including incisors, very much worn: 
zygomata slightly broken; angular process of left ramus of mandible 
broken; the following teeth missing: right m 2, m 3; right m 2, m 3; 
left in 3 : skull otherwise perfect. 

Remarks. — This species is common throughout its range and is 
represented in most collections by at least a few specimens. It is 
often called big-eared mouse, leaf-eared mouse, and similar names, on 
account of its unusually large external ears. These are relatively 
larger than in any other species found north of Mexico, but they vary 
somewhat in size and may be approximated in forms like nasutus and 
rowleyi. Fortunately, however, the large internal audital bullae of 
truei are as characteristic as the large external ears, and the possession 
of both is usually diagnostic of any given specimen. Fully adult 
specimens of truei in good pelage are readily recognizable, for the 
combination of large ears, large orbicular audital bulla?, finely haired 
tail, and long, soft, and chiefly ochraceous pelage is not found in any 
other species. But, as is often true, immature specimens, or those in 
unusual or poor conditions of pelage, may prove difficult to place. 

The several subspecies of truei preserve most of its general char- 
acters fairly well, and differ from it chiefly in size, length of tail, 
or shade of color, combined with slight cranial peculiarities. Inter- 
gradation with gilberti, martirensis, and gratus occurs beyond any 
reasonable doubt. 

There are three synonyms, megalotis, which appears to be exactly 
equivalent to truei, and lasius and montipinoris, which may be re- 
garded as approaching gilberti, for though they retain the coloration 
of truei (even in its extreme phases) they differ in slight cranial 
characters that are practically the same as those of gilberti. 

1909.] TRUE] GROUP — GILBERTI. 1() ( .) 

Specimens examined. — Total number 47r». from localities as fol- 

Arizona: Black Tank, Painted Desert, 2; Grand Canyon (top), 1; IIoI- 
brook, 10; Ke.un Canyon, 9; Moccasin Sprint,'. ."> : Springerville, :>2; 
Walnut. 4. 

California: Coleville, .Mono County, G; Coso, 1; Fort Tejon, 3; Inyo 
Mountains. 12: Kornville, 2; 2.~» miles above Kernville, 1; South 
Fork Kern River, 1 : Lone Pine, 1 : Long Valley. Mono County, 1 : 
Millforil, 1; near Morongo Valley, 3; Mojave, 9; New York Moun- 
tain, .*!: Panamint Mountains, 4<>; Piute Mountains, 2; Providence 
Mountains. '.»: San Emigdio Canyon, 1 (approaching gil]berti) : Susan- 
ville, 2; Tehachajpi Peak, 4 (approaching gilbert i) ; Walker Pass, 6; 
White Mountains, 2. 

Chihuahua: Casas Grandes, 2; Colonia Garcia, 7. 

Colorado: Ashbaugh Ranch, 3; Coventry, ."J; De Beque. 1: Escalante 
Hills, 3: Gaume Ranch, 2; Glenwood Springs, 1: Cily, 2; McCoy, 1; 
Plateau Creek, 2; Rangeley, 2: Rinehart Station (20 miles south of 
Lamar), 1 ; Rifle, 1 : Salida, 1 : a Uncompahgre Plateau, 1. 

Nevada: Anderson Ranch, Douglas County, L6; Charleston Mountains. 8; 
Gardnervflle, 5: Grapevine Mountains, 2: Panaca, 1 : Reese River, 1 : 
mountains 10 miles east of Stillwater, 2. 

New Mexico: Abiquiu, 1; Ancho, 1; Aztec, 3; Burro Mountains. 2; Capi- 
tan Mountains, 34; Cienequilla, 2; Cloudcroft, 1; Corona, 6; Cuervo, 
3; Dog Spring, 1; Datil Mountains, 7; Espanola, 1; Fort Wingate, 
26; Gallina Mountains. 5; Gallup, 4; Gila National Forest, 3; Glen- 
wood, 1; Grants, 1; Hale Ranch, near Ruidoso, 5; Isleta, 4; Jamez. 
1; Jicarilla Mountains, 36; Laguna, 2; La Plata, 5; Manzauo Moun- 
tains, 20; Mesa Jumanes. 1; Pecos, 3; Ribera, 3; Rinconada, S: 
San Andres Mountains, 4; Saudia Mountains, 4; Santa Rosa, 16; 
Sierra Grande, 3: Silver City. 4; Weed, 1. 

Utah: Beaver River, near Fort Cameron, 3; Browns Park, 1; Henry 
Mountains (cast slope Mount Ellen), 1: St. (ieorge, 1. 


Sitomys gilberti Allen, Bull, Am. Mus, Nat. Hist., N. Y.. V, pp. 188-189, Aug. 

18, 1893. 
Peromyscus gilberti Allen, supra cit., VIII, p. 267, Dec. 4. 1S96. 
Peromyscus dyselius Elliot, Field Col. Mus., Chicago. Zool. Ser., I, pp. 207-208, 

Mar., 1X98.— Portola, San Mateo County. Calif. 

Type locality. — Bear Valley, San Benito County, Calif. 

Geographic distribution. — Mountains and foothills of the interior 
of California and the coast south of San Francisco Bay ; north to 
central Oregon. Chiefly Upper Sonoran zone. 

Characters. — Similar in general to P. tn/ei. but color darker and 
richer; ears and audital bulla? averaging slightly smaller; pelage 
usually not so long and silky. Somewhat similar to P. boylei, but ears 
and audital bulla? smaller. 

Color. — Umvorn pelage : Similar to that of trnei, but darker and 
richer, ground color a deeper shade of ochraceous, often nearly tawny, 

a Collection of E. R. Warren. 


dusky mixture more copious; general effect often approaching cinna- 
mon and russet ; lateral line usually well-defined, ochraceous to tawny ; 
orbital ring more blackish and more sharply defined than in truei; 
dusky markings intensified throughout; pectoral spot frequently 

Skull. — Similar to that of truei, but averaging slightly smaller with 
slightly smaller audital bullae; zygomata somewhat lighter anteriorly 
and not so deeply notched by infraorbital foramen. Somewhat sim- 
ilar, to that of P. boylei, but audital bulla? decidedly larger and more 
nearly orbicular. 

Measurements. — Average of 5 adults from Gilroy, Calif.: Total 
hngth 200 (186-206); tail vertebra- 98 (87-108); hind foot 22.5 
(22-24) ; ear from notch (dry) 19.2 (18-21). 

Type specimen. — No. 329 Collection of Stanford University. 
S adult. Apr. 1, 1893. C. H. Gilbert and W. W. Price. Specimen 
in good condition. 

Remarks.- — This form differs from truei in much the same way 
that boylei differs from rowleyi. It is perhaps more difficult to dis- 
tinguish from boylei than truei is from rowleyi. Its external ears 
are somewhat smaller than those of truei and therefore approach 
more closely the size of those of boylei. The color is in many cases 
practically indistinguishable from that of boylei. The ears average 
considerably larger than in boylei. but the only certain means of dis- 
tinguishing specimens of all ages and pelages is in the skulls, in 
which the audital bulla 1 are large and rounded in gilberti and de- 
cidedly smaller and more nearly triangular in outline in boylei. The 
close resemblance of these forms in size, proportions, and color has 
led to some confusion, for the excellent cranial characters that dis- 
tinguish them have not always been appreciated. Quite recently one 
author" has stated in very positive terms that boylei and gilberti are 
absolutely alike, a conclusion doubtless formed without reference to 
cranial characters. The truei and boylei groups seem to be every- 
where distinguishable by certain general characters which are still 
present, but less pronounced and therefore sometimes overlooked, 
in the representative forms found in central and western California. 
The extreme of dark color is found in specimens from the heavily 
forested Santa Cruz Mountains, but specimens nearly or quite as 
dark are found practically at the type locality of gilberti and at 
other localities somewhat removed from the coast. The name dyselius 
has been given to this extreme, but since gilberti is an earlier name 
and applicable to the darker form as opposed to the paler form truei. 
it does not seem advisable to recognize dyselius. for if it were done. 
gilberti would be left as an indefinable intermediate between trui i 

" Elliot, Field Col. Mus., Zool. Ser., I. pp. 207-208, March, L898. 


and dyselius with a decided leaning toward the latter. It would have 
been fortunate if the extreme of the dark form had received a name 

Specimens examined. — Total number 493, from localities as 
follows : 

California: Alameda Creek, Santa Clara County, 4; Alum Rock Park, 
near Mount Hamilton, 20; Middle Fork American River, near Au- 
burn, 2; Baird, 2; Bartlett Springs, 1; Bear Gulch, Alameda County. 
2 ; Bear Valley, San Benito County, 15 : Berger Creek, 1 : Berkeley, 10 : 
Beswick, 8; Big Basin, Santa Cruz County. 1 ; Big Pine Mountain. 1 : 
Boulder Creek, 8; Briceland, 1; Calabasas, 2; Calistoga, 4; Camp 
Meeker, 2; Carbondale, 3; Chico, 2; Coarsegold, 8; Cold ('reck. 3; 
Cone Peak, 1; Coulterville, 1; Edgewood, 3; Eel River, near South 
Yolla Bolly Mountain, 1; Eshom Valley, Tulare County, 1: Fall 
River Valley, 3 (approaching tniei); Fremont Peak, Gabilan 
Range, 1; Freshwater Creek, 3; Fresno Flat, 2; Gasquet, 2: Gaviota 
Pass, 1; near Gilroy, 0; Guenoc, 1; Hoopa Valley. 7: Hornbrook, 1; 
Hurleton, 8: Jolon, 3; East Fork Kaweah River, 2; King City, 1: 
Laguna Ranch, 3; La Honda, 0; La Panza, 1; Learly Ranch, Men- 
docino County. !>; near Lower Lake. 32; Marysville Buttes, 41: 
Monterey, 0; Montgomery. 3; Mount Hamilton, 30; Mount St. 
Helena, 20; Mount Sanhedrim 13: Nelson (8 mi. E. ), 0; Nicasio, 3: 
Oakland, 3; Pacheco Pass, 1; Pacheco Peak. 4: Palo Alto. 5; 
Paraiso Springs, 2; Paso Robles, 5: Pescadero Creek. Santa Cruz 
Mountains, 13; Picard, 1; Pleyto, 3; Portola, 29; Posts, 2; Pozo, 1: 
Quincy, 1; Raymond. 3; Bedding, 2; Round Valley, 2; Salt Springs, 
Fresno River. 1 ; San Antonio, 43: San Lorenzo Creek, 2; near San 
Simeon, 1 ; top of Santa Cruz Mountains, near Santa Cruz, 1 : Santa 
Lucia Peak, 3; near Santa Rosa, 1: Scott Valley. 2: Sherwoods, 5 : 
Tassajara Creek, 4; Tracy, 1; Ukiah, 2: Willits, 0; Woodside, 1. 
Oregon: Crooked River. 25 miles southeast of Prineville, 2 (approaching 
truei?) : Grants Pass. Rogue River Valley. (>. 


Sitomys martirensis Allen. Bull. Am. Mus. Nat. Hist., N. Y.. V, pp. 1N7-1 xs. 

Aug. 18, 1893. 
[Peromyscus] martirensis Trouessart, Catal. Mamni., p. 516. 1897. 
Peromyscus hemionotis Elliot. Field Col. Mus., Chicago, Zool. Ser., Ill, p. 157. 
April, 1903. — Rosarito Divide. San Pedro Martir Mountains. Lower Cali- 
Type locality. — San Pedro Martir Mountains, at 7.000 feet altitude. 
Lower California, Mexico. 

Geographic distribution. — San Pedro Martir and adjacent ranges 
of mountains of northern Lower California, and northward to the 
San Jacinto and San Bernardino mountains of southwestern Cali- 

Characters. — Color and general characters practically as in truei; 
tail considerably longer: audita! bulla^ averaging slightly smaller. 


Color. — Practically as in true'/; June and July specimens in 
slightly worn pelage are chiefly ochraceous buff: the dusky markings 
on the tarsal joints are much reduced and scarcely obvious. 

8kvll. — Similar to that of truei; zygomata slightly more com- 
pressed anteriorly; audita! hullse averaging slightly smaller, but still 
much larger than in rowleyi or hoylei. 

Measurements. — Average of G adults from La Grulla, San Pedro 
Martir Mountains: Total length 213 (205-222); tail vertebra- 116.5 
(112-122) : hind foot 24: ear from notch (dry) 21.7 (21-23). 

Type specimen. — No. ff j| American Museum of Natural History, 
New York. May 8, 1893. A.W.Anthony. Skin in good condition. 
Skull with last right m missing; parietal depressed on one side, evi- 
dently from injury in life, giving the orbit a slightly beaded effect. 

Remarks. — The long tail of this form is its chief distinguishing 
character. Specimens in all pelages are not yet available, but judg- 
ing from June and July material, no color difference separates it 
from typical truei. The type and nearly all other specimens exam- 
ined are in a very bright ochraceous buff pelage exactly like com- 
parable specimens of truei. Certain slight cranial characters, though 
not present in every specimen, seem to have a value as average dif- 

Specimen* examined. — Total number 90, from localities as fol- 
lows : 

California: San Bernardino Mountains, S; San Jacinto Mountains, 2; 
Summit Coast Range, San Diego County, 1. 

Lower California: Aguaje de las Fresas, 2; Agua Escondido, 4 ; El Kayo. 
Hanson Laguna Mountains. 2; Hanson Laguna, Hanson Laguna 
Mountains, 17; La Grulla, San Pedro Martir Mountains, 13; Pifion. 
west slope San Pedro Martir Mountains, 11; Kosarito Divide, 1 ; San 
Matias Spring, 1 : San Pedro Martir Mountains at 7,000 feet altitude, 
4; Santa Eulalia, 9; Santa Rosa, 7; Valleeitos. 8. 


Type from La Laguna, Laguna Mountains, Lower California, Mexico. No. 
147004 U. S. National Museum, Biological Survey Collection. 9 adult. 
Jan. 20. 1900. E. W. Nelson and E. A. Goldman. 

Geographic distribution. — Mountains of the region of the extremity 
of the peninsula of Lower California, Mexico. 

Characters. — General characters as in truei; ears smaller; tail rela- 
tively longer: skull smaller and lighter. 

Color. — Essentially as in truei. Underparts ochraceous buff mixed 
with fine lines of dusky; nose and postorbital region grayish: a nar- 
row dusky orbital ring: feet white, tarsal joint dusky: tail brownish 
dusky above, white below: underparts creamy white. 

Skull. — Much as in truei and martirensis but smaller and lighter: 
rostrum and nasals more slender; zygomata more compressed an- 


teriorly; molar teeth and audital bullae smaller; interparietal rela- 
tively large. 

Measurements. — Average of 10 adult topotypes: Total length L93 
(182-210) ; tail vertebrae 105 (97-118) ; hind foot 22.4 (21.5-23) ; ear 
from notch (dry) 19 (18-19.8). 

Remarks. — This form, though not strongly characterized, is geo- 
graphically isolated and the recognition of its peculiarities, such as 
they are, seems inevitable. During the recent exploration of the 
peninsula of Lower California by Nelson and Goldman, no speci- 
mens of the truei group were found in the long stretch of country 
between the San Pedro Martir Mountains and the Laguna Moun- 
tains. Nevertheless, the isolated form here named lagunae differs 
from martirensis only in its slightly smaller size and more slender 

/Specimens examined. — Total number 48, from localities as follows: 

Lower California: El Sauz, 1; La Chuparosa, 8; La Laguna, 14: Mount 
Miraflores, 5; Sierra Laguna, 15; Victoria Mountains. ."». 


(PI. IV, fig. 9.) 

Peromyscus gratus Merriam. Proe. Biol. Soe. Wash.. XII, p. 123, Apr. 30, 1S98. 
Peromyscus sagax Elliot, Field Col. Mus., Chicago. Zool. Ser.. Ill, p. 142. Mar., 

1903. — Patzcuaro. Michoacan, Mexico. 
Peromyscus pavidus Elliot, supra cit., pp. 142-143. — Patzcuaro. Michoacan, 

Peromyscus zelotes Osgood, Proc. Biol. Soc. Wash.. XVII. pp. (37-68. Mar. 21, 

1904. — Querendaro, Michoacan, Mexico. 

Type locality. — Tlalpam, Valley of Mexico, Mexico. 

Geographic distribution. — South central Mexico, in the States of 
Hidalgo. Mexico, Michoacan, and Queretaro; possibly south to cen- 
tral Oaxaca. 

Characters. — Similar in general to P. truei; ears somewhat 
smaller; tail decidedly longer and rather more coarsely haired: 
color darker, with greater mixture of dusky; skull with shorter and 
relatively heavier rostrum. 

Color. — Unworn pelage: Ground color of upperparts ochraceous 
to ochraceous buff, heavily and nearly uniformly mixed with 
blackish: general effect isabella color to nearly sepia: facial region, 
nose, forehead, etc.. more grayish; lateral line nearly clear ochra- 
ceous, rather narrow but strongly contrasted: orbital ring sharp 
blackish; ears brownish dusky edged with whitish: feet white, tarsal 
joint marked with extension of dusky from hind leg; underparts 
creamy white, occasionally with a buffy pectoral spot; tail blackish 
above, white sometimes flecked with blackish below. Worn pelage: 


Genera] effect varying through brownish fawn, wood brown, and 
cinnamon to russet: middle of back usually distinctly darker than 
sides; lateral line blending more or less perfectly with sides; orbital 
ring and grayish postorbital region more contrasted than in unworn 
pelage; otherwise similar to unworn pelage. 

Skull. — General form as in truei; skull somewhat more compact 
and heavier: rostrum relatively shorter, broader, and heavier; brain- 
case full and high; nasals broad and often nearly flat; ascending 
branches of premaxillse even with, or slightly exceeding, posterior 
nasal endings: audita] bulla? large and full, but relatively smaller 
than in truei. 

Measurements. — Average of 10 adult topotypes: Total length, 204 
(191-225); tail vertebra?, 110.5 (103-125); hind foot, 22.8 (22-24) ; 
ear from notch (dry), 19 (17.5-20.2). 

Type specimen. — No. 50G19 U. S. National Museum, Biological 
Survey Collection. ? adult. Nov. 30, 1892. E. W. Nelson and 
E. A. Goldman. Specimen practically perfect. 

Remarks. — This is merely a longer-tailed and darker edition of 
truei with which intergradation occurs in north central Mexico. It 
is somewhat variable in cranial characters, but the nasals generally 
are broad, nearly flat, and rather short. Specimens from Michoacan 
as a rule have rather narrower nasals and large palatine foramina. 
but the variation is such that it seems inadvisable to recognize another 
form from this region. P. grains is distinguishable from levipes, 
spicilegus, etc.. which are nearly the same size, by its large audita 1 
bulla 1 , short nasals, and high narrow braincase. There are three 
synonyms. P. pavidus, /'. sagax, and P. zelotes, all described with- 
out suspicion of their relationship to gratus, comparisons being made 
with other forms. The type of zelotes has a rather heavy skull with 
rather small audita 1 bulla? and the skin shows a peculiar combination 
of worn and unworn pelages. Its resemblance both externally and 
cranially to the melanophrys group is striking and doubtless indicates 
relationship not very remote. A few immature and otherwise un- 
satisfactory specimens from Oaxaca and Huajuapam, Oaxaca, are 
provisionally referred to gratus. The relationship of grata* to dijfi- 
cilis is evidently very close, and where the two are found together 
they are difficult to distinguish by any character except size, and this 
is almost covered by variation. 

Specimens examined.— Total number 69, from localities as follows: 

Hidalgo: Ixmiquilpan, 1; Pachuca, 6; Tula, 2: Zinaapan, 2. 
Mexico: Ajusco, 1; Tlalparu, 2S. 

Michoacan: La Talma, 1: Patzcuaro, 5: Querendaro, 3: Zamora, 12. 
Oaxaca: Huajuapam, 3: Oaxaca, 1; Tamazulapam, 1. 
Queretaro: Tequisquiapam, 3. 

1 !»<»■». | TRUEI GROUP GENT1LIS. 175 


Peromyscus gratus gentilis Osgood, Proc. Biol. Soc. Wash., XVII, pp. til-<J2, 
Mar. 21, 11)04. 

Type locality. — Lagos, Jalisco, Mexico. 

Geographic distribution. — North central Mexico, chiefly in the 
States of Durango, Zacatecas, and northern Jalisco; east to southern 

Character*. — Similar to P. gratus. but paler; sides of head much 
more fulvous: molar teeth slightly smaller. 

Color. — Unworn pelage: Upperparts pale ochraceous buff, lightly 
mixed with dusky; middle of back with a slight concentration of 
dusky-tipped hairs; top of head, ear tufts, etc., with a predominance 
of buffy ; sides of head nearly clear ochraceous buff, with a slight tinge 
of grayish between eye and base of ear: eyelids black: underparts 
white; hands and feet white; tarsal joint dusky; tail bicolor. blackish 
above, white below. "Worn pelage: Upperparts varying from clear 
blight ochraceous buff on back and rump to grayish buff about head 
and shoulders, sometimes with a fine mixture of cinnamon-tipped 
hairs throughout; underparts white; tail dusky brownish above, 
white below. 

Skull. — As in typical P. gratus, having the same large braincase. 
short depressed rostrum, and relatively large audital bulla?; molar 
teeth slightly smaller. 

Measurements. — Average of 10 adult topotypes: Total length. '201 
(104-210) ; tail vertebra-, 111.7 (103-120) ; hind foot 23.8 (23-24.5) ; 
ear from notch (dry) 18.6 (18-19.3). 

Type spec} 'men. — No. 78937 U. S. National Museum, Biological 
Survey Collection. $ adult. June 27, 1896. E. TV. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — This form is practically like gratus except in color, 
which is decidedly paler and more nearly like that of truc't. How- 
ever, it is somewhat brighter even than truei and also differs from ii 
in its longer tail and cranial characters. Intergradation with both 
truei and gratus is amply shown by various specimens. 
Specimens examined. — Total number 36, from localities as follows: 
Coahuila: Sierra Encarnacion, 1 (approaching truei): Sierra • Guada- 
lupe, 1. 
Chihuahua: Parral, 1 : Sierra Madre, 4<> m. east of Batopilas, 1. 
Durango: Coyotes, 6; Durango, 2. 
Guanajuato: Silao, 3 (approaching gratus). 
Jalisco: Lagos, 12. 
San Luis Potosi: Jesus Maria. .">. 
Zacatecas: Valparaiso, 4: Zacatecas, 2. 



(PI. IV, fig. 8.) 

Vesperimm nasiltUS Allen. Bull. Am. Mus. Nat. Hist., X. ¥., Ill, pp. 299-300, 

Juno, 1891. 
! Peromyscus] truei nasutus Trouessart, Catal. Mamm., p. f>l7, 1S9T. 

Type locality. — Estes Park, Colorado. 

Geographic distribution. — Mountains of Colorado, New Mexico, 
eastern Arizona, and western Texas, chiefly east of the Continental 

Characters. — Color about as in rowleyi, but more grayish in sum- 
mer pelage; size larger: size and proportions about as in attwateri. 
color paler and more grayish; skull with longer rostrum; external 
ears sometimes nearly as large as in truei; ambulations of tail finer 
than in rowleyi. 

Color. — Unworn pelage: Practically as in rowleyi; general effect 
of upperparts grayish wood brown to Isabella color; ochraceous 
shades seldom or never accentuated : decidedly paler and more gray- 
ish than in attwateri. Worn pelage: Relatively dull, much duller 
than in either rowleyi or truei; general effect of upperparts pale 
grayish fawn lightly vermiculated with darker, occasionally bright- 
ening to a tinge of pinkish buff, but rarely or never attaining the 
ochraceous shades usual in rowleyi, attwateri. and truei. Adolescent 
and juvenal pelages: Darker than in rowleyi; plumbeous underfur 
deeper-colored and more mixed with dusky, occasionally quite soot} 7 . 

Skull. — About as in attwateri, but rostrum averaging slightly 
longer and audital bulla 1 more nearly spherical: similar to that of 
rowleyi but larger: audital bulla' actually somewhat larger than in 
rowleyi but relatively little or not at all larger; audital bulla 1 some- 
times actually nearly as large as in small specimens of truei, but 
relatively smaller: rostrum quite decidedly longer than in truei; 
nasals narrower and less flattened: zygomata more compressed an- 
teriorly, less deeply notched by infraorbital foramen: braincase 
averaging slightly broader and shallower. 

Measurements.— Average of 5 specimens from Gold Hill. Colo.: 
Total length 195 (180-210); tail vertebra? 99 (91-105): hind foot 

23.2 (2-J-24) : ear from notch (dry) 19.T (18.5-20.5). Of 10 adults 
from Grants. X. Mex. : 204 (199-206) ; 102 (98-109) ; 22.8 (22-21) ; 

20.3 (19.5-21). 

Type specimen. — No. fff£ American Museum of Natural History. 
Xew York. $ adult. Jan. 20, 1891. W. G. Smith. Skin rather 
poorly formed : tip of tail imperfect ; underparts greasy. Skull lack- 
ing posterior part of braincase, basioccipital, right audital bulla, and 
-mailer adjacent parts. 

11)00. J TRUEI GROUP POLKS. 177 

Remarks. — This species may be easily confused with either P. truei 
or P. b. rowleyi, and it is only after examination of a large amount 
of material (chiefly recently acquired) and the testing of various 
alternatives that its distinctness becomes apparent. The most obvious 
characters for separating truei and rowleyi, namely, size of external 
ears and of audital bulla?, are somewhat combined in nasutus. Since 
nasutus occurs throughout a considerable part of the ranges of truei 
and rowleyi confusion is further induced. However, nasutus has 
external ears and audital bulla? slightly larger than in roivleyi and 
slightly smaller than in truei. This is true as regards actual size, but 
since nasutus is larger than either rowleyi or truei, it is evident that 
its audital bulla? are relatively but little larger than those of rowleyi. 
It differs from both rowleyi and truei in its larger size, more grayish 
color (particularly in worn and partly worn conditions of pelage), 
and more elongate nasals. Its pelage is rather soft and full, more 
so than in rowleyi, and though not often so long, of a slightly different 
character from that of truei. In adolescent pelage there is a softness 
or fullness not seen in either truei or rowleyi, and its color then, 
though elush^e of description, is quite characteristic. Although 
nasutus has of late been associated with truei, it now seems that its 
closest affinities are elsewhere, quite probably with difficilis, and pos- 
sibly with rowleyi It is smaller than difficilis, has a shorter tail, and 
more grayish color, but its skull, though smaller, with smaller audital 
bulla', has the same general form, and certain specimens of difficilis, 
particularly those from the northern part of its range, appear to 
decidedly approach nasutus. 

Specimens examined. — Total number 188, from localities as 
follows : 

Arizona: Springerville, 8. 

Colorado: Boulder, 20: Canyon City, 1; Estes Park, 8; Gold Hill, !»; 
Trinidad, 10. 

New Mexico: Arroyo Hondo, 2; Arroyo Seco, 7; Capitan Mountains, 25; 
Catskill, 4; Cienequilla, 11; Clayton, 1; Corona, 1; Coyote Creek, 
3 ; Datil Mountains, 2 ; Emery Peak, 2 ; Folsorn, 4 ; Fort Wingate, 
1; Gallo Canyon, 1; Glorieta, 1; Grants, 17; Hall Peak, 2; Jicarilla 
Mountains, 10; Mora, 1; Peeos River, 3; Rineonada, 1; San Andres 
Mountains, 13: Santa Rosa. 3; Sierra Grande, 11; Tucumcari, 1. 

Peromyscus polius Osgood, Proc. Biol. Soc. Wash., XVII, p. 61, Mar. 21. 1004. 

Type locality. — Colonia Garcia, Chihuahua, Mexico. 

Geographic distribution. — Known only from the type locality. 

Characters.- — Similar to P. b. rowleyi and P. b. attwateri but larger 
(hind foot 25-2C>) and more grayish : molar teeth relatively large ami 
heavy: hind feet and tarsal joint white. 
66268— No. 28—00 12 


Color. — General color of upperparts grayish broccoli brown, pro- 
duced by a ground color of pinkish buff mixed with dusky; narrow 
lateral line clear pinkish buff; head slightly more grayish than body, 
particularly on cheeks; a narrow dusky orbital ring; tuft at base of 
ear mixed grayish and buffy ; ears grayish dusky, narrowly margined 
with buffy white; underparts pure white; feet and carpal and tarsal 
joints white; tail bicolor; pale brownish dusky above, white below. 

Skull. — Similar in general form to that of rowleyi, but decidedly 
larger; molar teeth decidedly larger; palatine slits longer; audital 
bulhe actually about same size, relatively smaller. Size about as in 
large specimens of attwateri, but molar teeth actually and relatively 
larger and heavier. 

Measurements. — Average of 8 adult topotypes: Total length 218.5 
(210-234) ; tail vertebra? 117 (111-120) ; hind foot 25.8 (25-26) ; ear 
from notch (dry) 18.1 (17.2-18.5). 

Type specimen. — No. 98226 U. S. National Museum, Biological 
Survey Collection. 9 adult. June 26. 1899. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — This species nearly equals P. difftcUis in size, but its 
shorter tail and ears at once distinguish it without recourse to the 
skull, in which the audital bulla? are scarcely more than half the size 
of those of difficilis. It considerably resembles rowleyi, and espe- 
cially attwateri, but is readily distinguished from either by its white 
' ankles,' a character that may possibly indicate that its real relation- 
ship is with the much smaller but generally similar species, P. eremir 
coides. Nearly typical rowleyi is found at the type locality of 
poll us and preserves its distinctness there. 

Specimens examined. — Total number 11, all from the type locality. 

Key to subspecies of Peromyscus diffiicilis. 

Color very dark, chiefly rich blackish brown and black P. d. felipensis 

Color paler, chiefly ochraceons buff more or less mixed with dusky. 

Size averaging smaller; pelage closer and more glossy; skull with smaller 

braincase p. difficilis 

Size averaging larger ; pelage looser and duller ; skull with larger braincase. 

P. d. amphts 


(PI. V, fig. 6.) 

Vesperimus difficilis Allen, Hull. Am. Mus. Nut. Hist.. N. Y., Ill, pp. 298-2'.t9, 

June, 1891. 
[Peromyscus] difficilis Trouessart, Catal. Mamm., p. 518, 1897. 

Type locality. — Sierra de Valparaiso, Zacatecas, Mexico. 

Geographic distribution. — Sierra Madre from southwestern Chi- 
huahua south through Durango and Zacatecas, then east and south- 
east to certain mountainous parts of Guanajuato and northern Hi- 




dalgo, and thence north through parts of San Luis Potosi to moun- 
tains of southern Coahuila. Chiefly in Transition zone. 

Characters. — Size rather large (hind foot 24-28) ; tail long, al- 
ways longer than head and body; ears rather large; relatively larger 
than in other large Mexican species; general appearance that of a 
decidedly larger and longer tailed counterpart of P. truei gratus; 
skull with rather long nasals, full braincase, and large audital bulla?. 

Color. — Unworn pelage: Similar in general to that of P. truei 
gratus, somewhat darker than in truei; ground color of upperparts 
ochraceous buff mixed with dusky, chiefly disposed as fine lines and 
rather dominating the gen- 
eral effect; sides, except 
lateral line, same as back; 
lateral line clear ochra- 
ceous buff, and usually 
fairly well defined: nose, 
postorbital region, and gen- 
eral facial region above lat- 
eral line quite distinctly 
grayish ; ears thinly haired, 
margined with whitish, 
tufts at bases about the 
same color as surrounding 
parts; a narrow blackish 
orbital ring; underparts 
creamy white, usually with- 
out any pectoral spot ; feet 
white, tarsal joint with a 
small dusky marking; tail 
sharply bicolor, blackish 
brown above, white below. 
Worn pelage: General ef- 
fect of upperparts varying 
from dull fulvous drab to rather bright cinnamon; head and shoul- 
ders usually considerably more grayish than back and rump; lateral 
line scarcely or not at all distinct from rest of sides. 

Skull. — Similar in general form to that of nasutus but larger, 
heavier, and with larger audital bullae; braincase full and deep: in- 
terorbital space narrow; supraorbital border not beaded and seldom 
very sharp-angled, never forming any distinct shelf as in melanoph- 
rys; nasals quite elongate; teeth moderate; audital bulla? large and 
full, relatively smaller than in gratus but decidedly larger than in 
most other Mexican species. 


Ttyscas diffici//.s 

. . (. 


H d. fe//p en s/s 


-Distribution of Peromyscus ilifflcilis and 


Measurements. — Average of 10 adult topotypes: Total length 233 
(212-255); tail vertebrae 127 (115-143); hind foot 26.3 (25.5-28); 
ear from notch (dry) 21 (19.5-23.5). 

Type specimen. — No. lift American Museum of Natural History, 
New York. $ adolescent. July 27, 1889. Audley C. Buller. Skin 
rather badly made, feet and tail twisted, and underparts stained, 
but still fairly satisfactory for comparison. Skull with cracks in 
basioccipital and interorbital part of frontal; anterior part of right 
zygoma absent. 

Remarks. — The relationship of difficilis and its subspecies to the 
truei group is quite apparent, but there is no absolute connection 
between the two groups unless it be through nasutus, which may be a 
northern representative of difficilis. Thus in south central Mexico 
the two groups are represented by difficilis and gratus, and are there 
usually easily distinguishable by size alone ; in New Mexico, Colorado, 
etc., are truei and nasutus, representatives of the same two groups, but 
with characters more nearly approximating each other, and therefore 
more difficult to distinguish. P. difficilis is readily distinguishable 
from other Mexican species of corresponding size by its larger ears 
and its unbeaded skull with large rounded audital bullae. The bullae 
are approached in size by those of P. melanophrys, but in that specie's 
the external ears are decidedly smaller and the supraorbital border 
of the skull is developed into a slight shelf often even suggesting a 
bead. Variation in cranial characters is considerable, but most of 
it appears in specimens from intermediate localities. Specimens 
from Hidalgo for the most part appear to be intermediate between 
difficilis and amplus. A large series from near Jesus Maria. San 
Luis Potosi, shows cranial variations almost covering the differences 
from nasutus to amplus. The most northerly specimens, as those 
from near Guadalupe y Calvo, have bullae uniformly smaller than 
the average of typical difficilis, and appear to approach nasutus. 
They are best referred to difficilis, however, and the difference be- 
tween them and nasutus is still sufficient to make it advisable to hold 
the two for the present as distinct species. Specimens from the 
mountains of Coahuila also are not quite typical, being unusually 
grayish, but this is perhaps due, at least in part, to age and condition 
of pelage. Another possible relative of difficilis is P. polius, which 
has a shorter tail, white tarsal joints, and also cranial characters. 

Specimens examined. — Total number 255, from localities as fol- 
lows : 

Chihuahua: Batopilas (mountains 65 in. east), 6; mountains near 

Guadalupe y Calvo. 17. 
Coahuila: Carneros. 12: Sierra Encarnacion, 1!); Sierra Guadalupe, 26. 
Durango: 101 Sal to, 10. 
Guanajuato: Santa Rosa, 20. 


Hidalgo: Encarnacion, 9; Ixruiquilpan, 7; Zimapam, 14. 

San Luis Potosi: Charcos, 5; mountains near Jesus Maria, 37 

Tamaulipas: Miquihuana, 25. 

Zacatecas: Plateado, IS; Valparaiso Mountains, 2fi; Zacatecas, 14. 


Peromyscua ampins Osgood, Proo. P>iol. Snc. Wash.. XVII, pp. f;2-r>.'',. Mar. 21. 


Type locality. — Coixtlahuaca, Oaxaca, Mexico. 

Geographic distribution. — Mountains of north central Oaxaca. 
Puebla, southeastern Veracruz, and southern Hidalgo. 

Characters. — Similar to P. difficilis and P. d. felipensis; color 
much as in difficilis but duller; size and cranial characters as in 
felipensis; color very much paler; pelage long and lax. usually lack- 
ing the gloss or luster shown in difficilis; skull large, with a broad 
full braincase. 

Color. — Type: General effect of upperparts uniform clay color 
produced by a ground color of ochraceous buff and a fine peppery 
mixture of dusky; lateral line rather broad, ochraceous buff; fore- 
head and orbital region from posterior base of whiskers to ear gray- 
ish ; anterior base of whiskers buffy ; underparts creamy white, with 
a well-developed ochraceous buff pectoral spot; feet white, tarsal 
joints marked with dusky; tail dusky brownish above, white below. 

Skull. — Similar in general to that of difficilis, but larger and 
heavier throughout; rostrum and nasals broader and heavier; practi- 
cally as in felipensis. but braincase averaging slightly higher and 
fuller; audital bullae large, but relatively slightly smaller than in 
difficilis; interorbital space narrow; no supraorbital bead. 

Measurements. — Average of 10 adult topotypes: Total length 248 
(235-260); tail vertebrae 136 (1-28-145); hind foot 27 (26-28); ear 
from notch (dry) 20.9 (19.5-21.8). 

Type specimen. — No. T0158 U. S. National Museum, Biological 
Survey Collection. 9 adult, Nov. 12, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — In cranial characters, amplus differs from difficilis in- 
the same way that felipensis does. Its color is similar to that of 
difficilis. but there is less dusky mixture and this is not usually dis- 
posed as fine lines, but as a fine peppery sin-inkling. The pelage has 
a peculiar quality which baffles description, having less gloss or luster 
than in most other species. In this respect it resembles many speci- 
mens of the melanophrys group. It is easily distinguished from 
melanophrys by the absence of a definite supraorbital ridge and by its 
larger audital bullae. It intergrades with both difficilis and felipen- 
sis. Specimens from northern Hidalgo show considerable approach 
to difficilis. while among series of felipensis are occasional paler 
specimens evidently aproaching amplus. 


Specimens examined. -Total number L33, from localities as fol- 
lows : 

Hidalgo: Irolo, 16; Marques, 5; Pachuca, <', ; Real del Monte, 8; Tula, 14; 

Tulancingo, 8. 
Oaxaca: Coixtlahuaca, 1(5: Tamazulapam, 12. 
Puebla: Chalchicomula, 9; Esperanza, 18. 
Tlaxcala: Apixaco, 2. 
Veracruz: Maltrata, <>: Perote, 14. 


Peromyscus felipensis Merriam, Proe. Biol. S<»c Wash., XII, pp. 122-123, Apr. 
30, 1898. 

Type locality. — Cerro San Felipe, Oaxaca, Mexico. Altitude 
10.300 feet. 

Geographic distribution. — High elevations (8,000 feet to 11,000 
feet) on the mountains surrounding the Valley of Mexico; reap- 
pearing at similar elevations in the mountains northeast of the city 
of Oaxaca. 

Character*. — General characters as in difficilis and amplus; color 
very much darker than in either, rich blackish brown and pure black 
predominating; pelage somewhat heavier, more woolly; ears averag- 
ing smaller; size slightly larger than in difficilis; skull larger and 
heavier; braincase averaging flatter than in amplus. 

Color. — Unworn pelage : Upperparts mixed grayish ochraceous 
buff and black; general effect on dorsum nearly black, lightly 
sprinkled with buffy gray, on sides nearly hair brown becoming more 
huffy toward lateral line, which is ochraceous buff mixed with dusky 
and seldom very sharply contrasted with rest of sides; sides of face, 
nose, and forehead tinged with grayish; blackish markings every- 
where accentuated; orbital ring and spot at base of whiskers sharply 
black; spot on each side of nose in front of whiskers, buffy; white 
of lips ascending to lower edge of dusky spot at base of whiskers; 
feet white, tarsal joint with a broad blackish brown marking; tail 
sharply bicolor, blackish brown above, white below, but usually with 
some mixture of dusky on the underside near base; underparts 
creamy white modified by the blackish slate undercolor w T hich is 
never entirely concealed; pectoral region broadly ochraceous buff. 
Worn pelage: Upperparts more uniform, with dorsum less differ- 
entiated; ends of hairs worn down and exposing considerable of the 
blackish slate undercolor; general effect varying from dark hair 
brown to sepia; lateral line scarcely apparent; underparts much 
modified by blackish slate undercolor. Young in first coat : Median 
upperparts deep blackish slate, very lightly flecked with gray; sides 
slate gray lightly vermiculated with darker. 

!■<!,■ nil. — Similar to that of difficilis, but somewhat larger; rostrum 
and nasals broader and heavier; audital bullae relatively smaller; 

,1909.] TRUEI GROUP — BULLATUS. 183 

braincase averaging broader and shallower; practically as in amplus 
but braincase averaging slightly shallower. 

Measurements. — Average of 10 adult topotypes: Total length 241.5' 
(225-248); tail vertebrae 127 (118-182); hind foot 26.8 (25.5-27.5); 
ear from notch (dry) 20.4 (19-21.7). 

Type specimen. — No. 08409 U. S. National Museum, Biological 
Survey Collection. $ adult. Aug. 22, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — Its very dark color readily distinguishes this form 
from difficilis and amplus, and its cranial characters are likely to 
prevent confusion with any others. The audita! bulla? are not so 
full and rounded as in difficilis but still are larger than in most other 
Mexican species. P. lepturus also is dark colored, but will scarcely 
be confused with felipensis on account of its smaller size, smaller 
audita] bullae, and relatively larger teeth. In nearly all other Mexi- 
can species at all similar to felipensis the interorbital region is broad- 
er, with some development of a supraorbital ridge. 

The distribution of felipensis is curiously interrupted, Cerro San 
Felipe being apparently quite isolated from the other localities from 
which the form is known, while am/plus is found on mountains in the 
intervening region. Possibly felt pen sis occupies higher or more hu- 
mid regions. 

Specimens examined. — Total number 41, from localities as follows: 
Mexico: Ajusco, «". ; Amecameca, 8; Toluca Valley, 5; Salazar, 4. 
Oaxaca: Cerro San Felipe, 21. 

(PI. VII, fig. 7.) 

Peromyscus bullatus Osgood, Prne. Biol. Soc. Wash.. XVII, p. 63, Mar. 21, 1904. 

Type locality. — Perote, Veracruz. Mexico. 

Geographic distribution. — Known only from the type locality. 

Characters. — Similar in general to P. truei and P. difficilis; ears 
very large; audital bulla' greatly inflated; tail shorter than head and 

Color. — Similar to that of P. truei. but richer, more nearly ap- 
proaching tawny; slightly paler than in difficilis; sides and ground 
color of upperparts tawny ochraceous; dorsum with considerable 
dusky producing a general effect of nearly broccoli brown; top of 
head and nose broccoli brown ; sides of head between base of ear and 
eye distinctly grayish; a narrow dusky orbital ring: underparts 
creamy white; feet white, tarsal joint marked with dusky; tail 
brownish dusky above, white below. 

"The tail of the type and only specimen is slightly imperfect, having lost 
the extreme tip. hut its distal attenuation indicates that it was naturally but 
little longer, and certainly much shorter than that of P. difficilis. 



fxo. 28. 

Skull. — Similar in general form to P. truei; size larger than P. 
truei, but smaller than P. difficilis; audita! bullae very much inflated, 
actually as well as relatively larger than in any other known species 
of the genus; braincase rounded and rather inflated; interorbital 
constriction relatively wider than in difficilis; nasals and palatine 
slits rather long; molar teeth large, actually larger than those of 
truei and nearly equalling those of difficilis. 

Measurements. — Type: Total length, 200; tail vertebrae, 93+ j hfnd 
foot, 23; ear from notch (dry), 25. 

Type specimen. — No. 54405 U. S. National Museum, Biological 

Survey Collection. ? adult. June 3, 

1893. E. W. Nelson and 
E. A. Goldman. Specimen 
in good condition except 
that extreme tip of tail is 
broken off. 

Remarks. — The relation- 
ships of this species are 
clearly with P. truei and 
P. difficilis. Its short tail 
and light color easily dis- 
tinguish it from difficilis, 
and its enormous audita! 
bulla? at once separate it 
from truei. The external 
ears also are very large, 
slight!} 7 exceeding those of 
difficilis as well as of all 
other species. It is con- 
ceivable that the single 
specimen known may be 
an abnormal individual of 
the difficilis group, but its 
characters are pronounced and not paralleled anywhere in the consid- 
erable variation found in difficilis. 
Specimens examined, — One, the type. 

Key to Subspecies of Peromyscus melanophrys. 

Color darker : a large buffy pectoral spot usually present P. m. samorw 

Color paler; underparts usually pure white or with only traces of a pectoral spot. 

Size larger; tail averaging more than 140; skull usually more elongate. South 
of the City of Mexico- P- melanophrys 

Size smaller : tail averaging less than 140 : skull relatively shorter, with shorter 
nasals and larger audita 1 bulla-. North of the City of Mexico. 

P. m. consobrinus 


(PI. V, fig. 3.) 

Hesperomys melanophrys Cones, Proc. Acad. Nat. Sci. Pliila., pp. 181-182, 
Dec. 15, 1S74. 

Fio. S. — Distribution of Peromyscus melanophrys, 

P. xciiiiiiis. .-iiid subspecies. 


Peromyscus leucurus Thomas, Ann. & Mag. Nat. Hist., Ser. 6, XIV, pp. .'5(i4 5, 

Nov., 1894. — Tehuantepec, Oaxaca, Mexico. 
Peromyscus leucurus gadovii Thomas. Ann. & Mag. Nat. Hist., Ser. 7, XI, pp. 

484^85, May, 1903.— San Carlos (=Yautepec), Oaxaca, Mexico. 
P[eromyscus] melanophrys Allen. Bull. Am. Mus. Nat. Hist., N. Y., IX, p. 51, 

Mar. 15, L897. 

Type locality. — Santa Efigenia, Oaxaca. Mexico. 

Geographic distribution. — Arid Tropical and Lower Sonoran re- 
gion of south central Mexico from sea level to arid mountains of 
5,000 feet altitude. States of Chiapas, Guerrero. Morelos, Oaxaca, 
and Puebla. 

Characters. — Size rather large; tail very long (usually more than 
140 mm.), annulations rather coarse but covered with short, stiff 
hairs; tail frequently tipped with white; ears large and nearly naked; 
heel hairy, occupying about one-fifth of the entire length of the foot; 
general color cinnamon or pale bufl'y finely flecked with black, no 
definite lateral line; a black orbital ring and conspicuous patch of 
gray around it ; skull with a sharp-angled supraorbital ridge, but 
without an interior sulcus as in banderanus. 

Color.— -No. 08058. Oaxaca City, Oaxaca. Adult 9 , June 13. 1804: 
Upperparts tawny ochraceous very finely lined with dusky; sides 
same color as back to line of demarcation between upper and under 
color; feet white, slightly dusky about ' ankles '; base of whiskers and 
ring around eye sharply black, remainder of face chiefly gray, which 
extends back to the base of the ear, and is somewhat mixed with 
tawny on forehead and lower cheeks; tail bicolor, dusky above, white 
below ; underparts creamy white, not quite subduing the plumbeous 
underfill'. No. 08404, Oaxaca City, ? adult, Aug. 15, 1894: Similar 
to the above, but decidedly darker, the ground color apparently some- 
what paler and less rufescent and the admixture of dusky much 
greater, causing the general color to appear russet or Mars brown; 
otherwise similar. 

Skull. — Size medium, smaller than in mexicanus; rostral part 
rather depressed as well as occipital, giving a nearly even curve to 
the outline of the skull ; a definite supraorbital ridge present, which 
is often developed into a trenchant shelf but not bounded on the 
inner side by a deep sulcus ; temporal region somewhat swollen ; 
nasals of moderate length and nearly even width, shorter and less 
cuneate than in mexicanus; braincase narrower and audital bulla? 
smaller than in difficilis; teeth about same size or slightly smaller 
than in mexicanus; audital bulla? slightly larger. 

Measurements. — Average of 3 adults from mountains near Tonala, 
Chiapas: Total length, 209 (202-275) ; tail vertebrae, 149 (140-155) ; 
hind foot, 28; ear from notch (dry), 19.3 (18.5-21). A very large in- 
dividual from Yaganiza, Oaxaca: 280: 103; 29. Average of 4 
adults from Totolapa, Oaxaca: 250; 154; 28. 

180) NORTH AMERICAN I'AIN A. I no. 28. 

Type specimen. No. tsHst U. S. National Museum. 9 adult. Skin 
and skull, collected July 11, 1871, by F. Sumichrast. The skin ap- 
pears to have been preserved in alcohol and later renovated. It is, 
however, in fairly good condition. The tail vertebra? have not been 
removed, but have been strengthened by a wire along their length 
outside. The right ear is somewhat torn, but the left is intact except 
that it seems to have lost the small amount of hair which originally 
clothed it. The condition of the pelage is of slight wear, and the 
general color of the upperparts is cinnamon tinged with fawn. The 
skull lacks the basioccipital and supraoccipital and the anterior part 
of the nasals is slightly broken. The teeth are perfect and almost 
unworn. The mandibles are perfect, except the angular processes 
which are slightly broken. 

Remarks. — P. melanophrys is the representative of a rather strik- 
ing group of large, very long-tailed mice inhabiting the more arid 
regions of southern Mexico. According to Mr. Nelson, it is found 
living chiefly among rocks. It may be distinguished from nearly 
all the other species of Mexico by its very long tail and slightly 
beaded skull. Like other members of the genus, it is subject to con- 
siderable variation in color, most of which seems to be clue to age. 
In nearly all series numbering upward of 10 specimens the older 
individuals are brighter colored, and occasional A-ery old ones are 
exceptionally bright. Young specimens may be either brownish or 
pale butty, apparently according to stage of development. P. gadovii 
of Thomas seems to represent specimens in the darker stage. A 
series from Oaxaca City, where 'gadovii' is said to be found 
(Thomas, 1. c), contains both light and dark examples. In any 
event, 'gadovii* becomes a synonym, as the type of melanophrys, 
which was not accessible to Thomas, is in the darker stage or phase. 
The relationship of P. leucurus to melanophrys was also evidently 
not suspected by its describer. One specimen from Tehuantepec, the 
type locality of leucurus. is somewhat immature, but agrees in every 
way with others of the same age from various parts of range of the 
species. The type of leucurus is rather paler than is usual through- 
out the group. 

Specimens examined. — Total number 85, from localities in Mexico, 
as follows : 

Chiapas: Near Tonala, 9; San Bartolome, 1 : San Vicente, 1. 
Guerrero: Ayusinapa, 1; Sochi, 1; Tlalixtaquilla, 7; Tlapa, 1. 
Morelos: Cuernavaca, 12: Yautepec, 2 (aberrant): Yecapixtla, 2. 
Oaxaca: Cuicatlan, 1; Las Vacas, '2; Mitla, 1; Puerto Ansel. 1: San 

Bartolo, 2: San Carlos, 1; San Miguel, 1 (aberrant); Oaxaca, 11; 

Santa Efigenia, 1 (type) : near Tebauntepec, 2: Tlapancingo, 1 : near 

Totolapa, 8; Yaganiza, 2. 
Puebla: Acatlan, 1 (approaching consobrinus) : Chalchicomula, 1; 

Piaxtla, 11; Tehuacan, 3 (approaching consobrinus). 



Peromyscus melanophrys zamorae Osgood, Proc. Biol. Soc. Wash., XVII, pp. 
65-60, Mar. 21. 1904. 

Type locality. — Zamora, Michoacan, Mexico. 

Geographic distribution. — South central Mexico between the ranges 
of melanophrys and consobrinus/ known from a few localities in the 

states of Hidalgo and Michoacan. 

diameters. — Similar to P. melanophrys, hut averaging slightly 
larger and darker; a large tawny pectoral spot present; skull com- 
paratively broad and heavy; teeth large. 

Color. — Similar in general to that of P. melanophrys, but appar- 
ently somewhat darker, the difference in this respect being very 
slight if any. Adults with a broad band of tawny across pectoral 
region between forelegs. Upper side of tail more nearly black than 
in melanophrys. 

Skull. — Similar to that of melanophrys, but slightly larger and 
heavier; braincase fuller and broader; audital bulla 1 larger; supra- 
orbital beads less trenchant and forming ridges rather than shelves 
anteriorly; molar teeth larger: other characters similar. 

Measurements. — Type: Total length. 2<>0 ; tail vertebrae, 141; hind 
foot, 29. Average of 7 young adult topotypes:' Total length, 259; 
tail vertebra, 114; hind foot, 28.4; ear from notch (dry), 20 (19-21). 

Type specimen. — Xo. 120288 U. S. National Museum, Biological 
Survey Collection. $ adult. Jan. 20, 1903. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — All adult specimens of this form thus far examined 
have the tawny pectoral marking highly developed. The constancy 
of this character may be doubted, as it is of such irregular occurrence 
in this genus. In the present case, while not diagnostic, it seems to 
be a character of importance. Of 76 specimens of melanophrys and 
consobrinus, only 4 have pectoral spots, and these are small and indis- 
tinct. Of 19 typical specimens of zamora}, all have well-marked 
pectoral spots except 2 plumbeous young, which have only traces. 

The majority of the series from Zamora are adolescents and, per- 
haps for this reason, are exceptionally dark. Even those that have 
not passed beyond the plumbeous juvenile pelage are decidedly darker 
than comparable specimens of typical melanophrys. Two adults, 
however, show only very slightly darker shades than melanophrys. 
Specimens from Zimapan, Hidalgo, are questionably referred to this 
form, but in cranial characters they approach consobrinus. Four 
specimens from Querendaro seem to be typical samoros. 

Specimens examined. — Total number 43, from localities in Mexico 

as follows: 

Hidalgo: Zimapan. 24 (aberrant). 
Michoacan: Querendaro, 4: Zamora, 15. 



Pefomyscus melanophrys consoorinus Osgood, Proc. Biol. Soc, Wash., XVII. p. 
G(i, March 21, 1904. 

Type locality. — Berriozabal, Zacatecas, Mexico. 

Geographic distribution. — Southern part of the Mexican table- 
land ; Sonoran zone in states of San Luis Potosi, Jalisco, Zacatecas, 

Characters. — Similar to P. melanophrys, but tail slightly shorter; 
skull with larger audita] bullae and other slight peculiarities. 

Color. — As in melanophrys. Topotype No. 58028, in full winter 
pelage (December) : Upperparts and sides tawny ochraceous, thickly 
lined with black to the edge of a narrow tawny lateral line; orbital 
ring black, sharply contrasting with a grayish area about it which 
extends from the base of the whiskers around the eye to the anterior 
base of the ear; underparts creamy white with a very small tawny 
pectoral spot; tail bicolor, white below, dusky above; feet creamy 
white, ' ankles ' dusky. 

Skull. — Similar to that of melanophrys, but somewhat shorter; 
nasals shorter and slightly broader; audital bullae larger; braincase 
more bulging and less elongate. 

Measurements. — Type: Total length, 250; tail vertebra 1 , 131; hind 
foot, 26.5. Average of 5 adult topotypes: Total length, 256; tail ver- 
tebra?, 135; hind foot, 27.5; ear from notch (dry), 19 (18-19.8). 

Type specimen. — No. 79626 U. S. National Museum, Biological 
Survey Collection. 9 adult, July 10, 1896. E. W. Nelson and E. A. 

Remarks.— This subspecies is not strongly marked, but its char- 
acters, such as they are, have great constancy throughout its range. 
It is apparently the form of the Mexican tableland, but its distribu- 
tion may be continuous with that of zamorce and thence with true 
melanophrys. Specimens from Zimapan, Hidalgo, appear to ap- 
proach consobrinus in cranial characters but retain the coloration of 

Specimens examined. — Total number 38, from localities in Mexico 
as follows : 

Agaias Calientes: Chicalote, 1. 

Guanajuato: Silao, 3. 

Jalisco: Atemajac, 16 (aberrant) ; Colotlan, 1. 

San Luis Potosi: Ahualulco, 1; Hacienda La Parada, 3. 

Zacatecas: Berriozabal, 12; Monte Escobedo, 1. 


Pcromyscus xenurus Osgood, Proc. Biol. Soc. Wash., XVII, P- 67, March 21. 

Type locality. — Durango. Durango, Mexico. 

Geographic distribution. — Known only from the type locality. 


Characters. — Similar in size and proportions to P. melanophrys; 
ground color more nearly fawn than tawny ; pectoral spot well devel- 
oped ; tail black, except a narrow ventral line of white; hind feet 
clouded with dusky. 

( 'olor. — Type, in fresh pelage except on rump : Ground color of 
upperparts grayish fawn color, gradually becoming more grayish 
anteriorly, so that, on account of the mixture of black throughout. 
the effect from the middle of the back forward passes from mixed 
fawn color through drab to hair brown; the rump, which is still in 
worn pelage, is fawn color; lower cheeks bright fawn color blending 
with gray, which covers most of the face from the base of the ears 
forward to the nose; underparts white except patch of bright fawn 
color extending from bases of forelegs across breast ; hind feet clouded 
with dusky brown to base of toes, which are creamy white; tail black 
all around except a narrow stripe of white on the underside occupy- 
ing scarcely more than one-fifth of the entire surface of the tail except 
distally, where the diameter of the tail being very slight, it nearly 
covers the underside. 

Skull. — Similar in general to that of P. m. ccmsobrinus ; nasals 
noticeably shorter; anterior palatine foramina shorter; postpalatal 
notch shorter and wider. 

Measurements. — The type and 1 adult topotype, respectively: Total 
length 246, 248 ; tail vertebrae 142, 140; hind foot 28, 28. 

Type specimen. — Xo. 04518 U. S. National Museum. Biological 
Survey Collection. 9 adult. July 1, 1898. E. W. Nelson and E. A. 
Goldman. Specimen in good condition. 

Remarks. — This species is easily distinguished from any other of 
the melanophrys group by the combination of large pectoral spot, 
dusky hind feet, and peculiar tail, with only a narrow line of white 
on the underside instead of the usual equal division of light and dark 
areas. It is the northernmost form of the melanophrys group, and at 
present is known only by two specimens from one locality, so doubt- 
less much remains to be learned of its distribution. Eventually it 
may be found to intergrade with consobrinus or zamorae. 

Specimens examined. — Total number 2, both from the type locality. 


Peromyscus melcisturus Merriam, Proc. Biol. Soc. Wash., XVII, pp. 124-125, 
Apr. 30, 1898. 

Ti/pe locality. — Chalchicomula, Puebla, Mexico. Altitude 8,200 

Geographic distribution. — Known only from the type locality. 

Characters. — Size medium (hind foot 24) ; tail very long, equaling 
three-fourths of total length, well haired and indistinctly bicolor: 
ears of moderate size; pelage rather full and thick, similar in color 


and general character to that of the melanophrys type, but under- 
pays creamy buff without any white: hind feet except toes chiefly 
dusky brownish, soles naked, at least medially; skull small with short 
nasals and unbended, much constricted frontals. 

Colo)'. — Ground color of upperparts ochraceous buff, becoming 
paler and more grayish anteriorly and brighter more nearly tawny 
posteriorly, and throughout mixed uniformly with dusky; back 
without any definite concentration of dusky, but essentially like sides; 
sides of face, nose, and forehead grayish; end of nose with a tiny 
nearly white tuft of hair surmounting rhinarium; orbital ring and 
spot at base of whiskers dusky; underparts cream buff, becoming 
paler, almost white on chin and throat; fore feet creamy white, hind 
feet dusky brownish except on toes and sides of feet ; tail dusky 
brownish above, mixed brownish and whitish below, thus being very 
indistinctly bicolor. 

Skull. — Size small, scarcely as large as that of grains; braincase 
rather long relatively to rostral part of skull, which appears dispro- 
portionately short; frontals much constricted anteriorly; supraorbital 
border without bead or shelf; zygomata squared anteriorly, some- 
what wider posteriorly; audital bullae moderate, smaller than in 
gratus, but relatively larger than in most other species of similar 
size; nasals short, flat, slightly cuneate, and but little depressed; 
interpterygoid fossa wide; posterior palatine foramina nearer to in- 
terptervgoid fossa than to anterior palatine foramina; molar teeth 
moderate, upper incisors very long. 

Measurements. — Type: Total length 249; tail vertebra? 155; hind 
foot 24; ear from notch (dry) 18.4. 

Type specimen. — No. 64108 U. S. National Museum, Biological 
Survey Collection. 9 adult. March 16, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in excellent condition. 

Remarks. — Although this species is distinct, with no very close 
allies, it is evidently more nearly related to melanophrys and sub- 
species than to any others. The general color, the character of the 
pelage, and the very long coarsely-haired tail are essentially as in 
melanophrys. The skull also bears a general resemblance to that of 
melanophrys, but is so much smaller that comparison is difficult. 

Specimen examined. — One. the type only. 


(PI. IV, fig. 12.) 

Peromyscus lepturus Merriam, Proc. Biol. Soc. Wash.. XII, pp. 118-11!), Apr. 
30, 1898. 

Type locality. — Mount Zempoaltepec. Oaxaca, Mexico. 
Geographic distribution. — Known only from the type locality. 
Characters. — Size medium (hind foot 27) ; tail about as long as 
or slightly shorter than head and body, rather coarsely haired, evenly 


bicolor or nearly uniform dusky above and below; color dark; pelage 
full, long, and lax; hind feet extensively marked with dusky; soles 
hairy posteriorly. Skull with rather long nasals, constricted and 
beadless frontals, large interparietal, and relatively large teeth. 

Color. — General effect of back brownish black, lightly mixed with 
cinnamon; sides, shoulders, and head cinnamon to russet, mixed with 
brownish black, producing a general effect approximating the bister 
of Eidgway; ears thinly clothed with soft brown hairs, scarcely or 
not at all edged with paler; tuft of soft hairs at anterior base of ear 
black; broad area from side of nose through base of whiskers to and 
around eye black or brownish black; underparts creamy white, 
usually modified to bluish gray by the effect of the slaty basal color 
of the hairs; pectoral region sometimes slightly marked with russet ; 
forearm sooty to carpal joint ; forefeet white ; dusky of hind leg ex- 
tending over tarsal joint and over the upper side of the hind foot 
two-thirds of the distance or quite to the base of the toes; toes and 
sides of hind feet whitish; tail variable, in some specimens nearly 
evenly bicolor. blackish above and white below, but usually more or 
less blackish on the underside near the base, in other specimens uni- 
form blackish above and below. 

/Skull. — Similar in general form to that of levipes; size slightly 
larger; nasals rather long and palatine slits correspondingly so; zygo- 
mata slightly compressed anteriorly, widest posteriorly ; frontals 
small and constricted, not beaded; supraorbital border scarcely even 
sharp-angled ; interparietal rather large ; superior outline of skull 
nearly flat or very slightly arched; molar teeth relatively large, larger 
than in levipes or mexicanus, but relatively about the same size as 
in the smaller species lophurus and simulatus; audital bullae moderate, 
about as in levipes. 

Measurements. — Average of 7 topotypes: Total length 228 (218- 
238) ; tail vertebra? 115 (112-119) ; hind foot 27 (2G-28) ; ear from 
notch (dry) 17.3 (16.4-18.2). 

Type specimen, — No. 68G12 U. S. National Museum, Biological 
Survey Collection. $ adult. July 8, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — This species is the largest of a small group including 
also lophurus and simulatus. From either of these it is distinguish- 
able by its larger size, more coarsely haired tail, and less arched 
skull. The same characters, as well as its dark color and other pecul- 
iarities, serve in large measure to distinguish it from levipes, aztecus, 
etc. P. m. totontepeeus, and P. melanoearpus, also found on Mount 
Zempoaltepec, are sometimes similar in color to Upturns, but their 
larger heavier skulls with relatively smaller teeth make close com- 
parison unnecessary. 


Specimens examined. — Total number 8, from localities as follows: 
Oaxaca: Mount Zempoaltepec at 8,000 feet altitude, 7 ; Totontepec, 1. 


(PI. Ill, fig. 6.) 

I'i •roiiu/scitx h>i>hunis Osgood, Proc. Biol. Soc. Wash., XVII, p. 72, Mar. 21, 1904. 

Type locality. — Todos Santos. Guatemala. Altitude 8,500 feet. 

Geographic distribution. — Highlands of the State of Chiapas, 
Mexico, and of western Guatemala. 

Characters. — Most similar to P. lepturus, but smaller and paler; 
tail long and covered with comparatively long soft hairs, and termi- 
nating in a distinct pencil; pelage soft and ; woolly ' and rather dull 
and lusterless; skull with large interparietal and short nasals. 

Color. — Type: General effect of upperparts between wood brown 
and fawn color, with a small dusky area in middle of back; lateral 
line pale ochraceous buff; underparts white; no pectoral spot: tail 
sepia brown, unicolor; forearm dusky to wrist, fore feet white; 
hind feet dusky brownish to base of toes; toes white; orbital ring 
dusky black, rather narrow, but expanded into a distinct spot in 
front of eye. 

Skull. — Similar to that of lepturus, but smaller and with rostral 
part decidedly shorter; molar teeth actually about same size, rela- 
tively larger; interparietal very large. Compared to that of P. 
levipes, the skull of lophurus is shorter, with shorter nasals and 
heavier infraorbital region: the teeth are decidedly heavier and 
longer and the interparietal larger. 

Measurements. — Average of 4 adult topotypes: Total length, 208; 
tail vertebra^ 105; hind foot 24.5; ear from notch (dry) 16. 

Type specimen. — No. 77219 U. S. National Museum, Biological 
Survey Collection. $ adult. Dec. 30, 1895. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — This very distinct species is easily recognized by its 
penciled tail and usually by the absence of white on the under side of 
the tail. All the specimens from Todos Santos have unicolor tails, 
but 2 from Calel are quite distinctly bicolor, and among 4 from San 
Cristobal, 2 have unicolor and 2 have imperfectly bicolor tails, indi- 
cating that this character is variable. The character of the pelage 
differs somewhat from most of the smaller species of Peromyscus in 
being dull and soft without the usual gloss, and although rather 
short it is fine and slightly ' woolly.' Its close allies are lepturus, 
which is larger and has a more flattened skull, and simulatus, which 
is decidedly smaller. 

Specimens examined. — Total number 17, from localities as follows: 

Chiapas: Piuabete, 5; San Cristobal, 4. 
Guatemala: Calel, 2; Todos Santos, 6. 



(PI. HI, Qg. 7.) 

Peromyscus simulatus Osgood, Proc. Biol. Soc. Wash.. XVII, pp. 72-7:>, Mar. 21, 

Type locality. — Near Jico, Veracruz, Mexico. Altitude C>.000 feet. 

Geographic distribution. — Known only from the type locality. 

Characters. — A miniature of P. lophurus (hind foot 21); dark 
markings slightly more intense; skull and teeth very small; tail 
clothed with long, soft hairs and penciled as in lophurus; audital 
bullae relatively large. 

Color. — Almost exactly as in P. lophurus; dark markings of feet 
and face slightly more intense ; tail chiefly broAvn, but with a narrow 
line of white on under side. 

Skull. — Size very small; similar in general to that of P. lophurus, 
but with more inflated braincase and depressed rostrum; audital 
bulla' relatively larger; interorbital constriction relatively wider; 
teeth very small. 

Measurements. — Type: Total length 169; tail vertebra? 87; hind 
foot 21; ear from notch (dry) 14.3. 

Type specimen. — No. 55028 U. S. National Museum, Biological 
Survey Collection. 2 adult. July 12, 1893. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — This small species is not closely related to any known 
species except P. lophurus, of which it is almost an exact miniature. 
Its skull is even smaller than that of P. melanotis, which occurs in 
the same region. It has, however, no relationship whatever to 
melanotis. Its small size, crested tail, and dark brown feet amply 
suffice to distinguish it from all other known species. A single 
specimen (No. 51177) from Tlalpam, Valley of Mexico, ma}^ repre- 
sent an undescribed subspecies of simulatus. It is quite immature, 
but seems to differ from simulatus in paler color, with the tail bicolor 
and the hind feet more extensively white. The skull, though imma- 
ture, agrees fairly well with adults of simulatus. 

Specimens examined. — Total number 2, both from the type locality. 


(PI. V. ti«. 2.) 

Peromyscus guatemalensis Merriam, Proc. Biol. Soc Wash., XII. p. lis. Apr. 
30, 189S. 
Type A'rr///7//.— Todos Santos, Guatemala. Altitude 10.000 feet. 
Geographic distribution. — High altitudes in western Guatemala 
and southern Chiapas. (See fig. 5, p. 1(31.) 
CU26S— No. 28— UU 13 


Characters. — Size about as in megalops, larger than mexicanus or 
furvus, but smaller than zarhynchus; tail longer than head and 
body, scantily haired, usually evenly bicolor, but sometimes irregu- 
larly blotchy below or rarely uniform dusky; pelage very long and 
lax; color very dark; skull with frontals constricted and without 
definite supraorbital bead. 

( 'oloi: — Unworn pelage : Upperparts chiefly pale cinnamon rufous, 
liberally mixed with dusky, the latter considerably concentrated on 
dorsum, forming an ill-defined stripe from shoulders to base of tail; 
general effect of sides russet, becoming Prout brown and nearly black 
toward middle of back; lateral line scarcely differentiated; a broad 
area from base of whiskers to and around eye and nearly to base of 
ear very dark, nearly pure black; tuft of soft hairs at anterior base 
of ear also nearly black; tip of nose grayish white; ears brownish, 
very lightly margined with whitish ; underparts buffy white, consid- 
erably modified by slaty under color; pectoral and axillary regions 
usually broadl} T cinnamon rufous; entire underparts, except chin and 
throat, sometimes suffused with cinnamon rufous; fore feet white; 
forearm brownish black nearly to carpal joint ; hind feet chiefly white, 
tarsal joint dusky brownish, this often extending over median upper 
side of hind foot halfway to base of toes; tail usually bicolor, under- 
side frequently irregularly blotched, dusky and yellowish; entire tail 
occasionally dusky. Worn pelage : General effect of upperparts 
russet to Mars brown and Prout brown; subterminal zone of color 
very narrow, allowing much of the slaty under color to appear; 
underparts buffy white, much modified by slaty. 

/Skull. — Similar to that of mexicanus but larger and broader with 
larger teeth and audital bulla?; nasals quite elongate; frontals con- 
stricted and slightly sharp-angled but not distinctly beaded ; brain- 
case rather large and full, decidedly broader than in mexicanus. 
Size, audital bulla?, and teeth about as in auritus, but frontals more 
constricted and without supraorbital bead. 

Measurements. — Average of 10 adult topotypes: Total length 267 
(252-290) ; tail vertebra? 138 (132-153) ; hind foot 30.7 (30-32) ; ear 
from notch (dry) 20.6 (20-21.5). 

Type specimen. — No. 76861 U. S. National Museum, Biological Sur- 
vey Collection. $ adult. Dec. 31, 1895. E. W. Nelson and E. A. 
Goldman. Specimen in good condition. 

Remarks. — P. guatemalensis appears to be most closely related to 
P. furvus and P. nndipes, both of which are somewhat smaller. It 
may be distinguished from megalops and auritus by its dark color, 
' woolly ' pelage, and unbeaded skull. From all other species, its size 
distinguishes it. It averages slightly larger than auritus and occa- 
sionally attains the size of smaller individuals of sarhynchus. There 
is some cranial variation in the comparatively small series examined. 


Specimens from Pinabete arc rather robust and their skulls have un- 
usually heavy rostrums. Others from Volcan Santa Maria have rela- 
tively large teeth. The relationship of guatemalensis to the smaller 
and more uniformly black-tailed species nudipes is not remote, and 
it is quite possible that intergradation between them may be found 
when specimens from the mountains of Nicaragua are obtained. 
Specimens examined. — Total number 59, from localities as follows: 

Chiapas: Pinabete, 8; Volcan de Tacama, 1. 

Guatemala: Calel, 21 : Todos Santos. 8; Volcan Santa Maria. 11; Zunil, 


Hesperomys (Vesperimus?) nudipes Allen, Bull. Am. Mus. Nat. Hist., N. V., 

III. pi). 213-214, Apr. 17, 1891. 
Peromyscus nudipes Thomas, Ann. & Mag. Nat. Hist., ser. <>, XIV, p. 365, Nov., 

Peromyscus cacabatus Bangs, Bull. Mas. Comp. Zool., XXXIX, pp. 29-30, figs. 

8-10, Apr., 1S92. 
Peromyscus nudipes Allen, supra tit., XX, pp. 67-68, Feb. 29, 1904. 

Type locality. — La Carpintera, Costa Rica. 

Geographic distribution. — Mountains of central Costa Rica and 
thence south to Chiriqui. 

Characters. — Similar in general to guatemalensis but slightly 
smaller; slightly larger than mexicanus; color very dark; pelage full 
and soft ; ears relatively small, nearly naked ; tail scaly with very short 
hairs, nearly imicolor; soles of hind feet narrowly naked medially; 
skull similar to that of guatemalensis but averaging smaller and 

Color. — Unworn pelage: Much as in guatemalensis^ but more ful- 
vous; sides chiefly russet to Mars brown, quite in contrast to back, 
which is much more mixed with dusky, forming a broad blackish 
brown area from shoulders to base of tail ; lateral line dark ochraceous 
buff, slightly contrasted with upper sides; underparts yellowish white 
with a broad pectoral spot of ochraceous buff, this sometimes quite 
produced posteriorly or even suffusing entire underparts except 
chin and throat; fore feet white, forearm dusky nearly to wrist; hind 
feet white usually with the broad dusky brownish marking on tarsal 
joint extended on upper side of foot about halfway to base of toes; 
tail usually unicolor brownish black, but occasionally with the scaly 
part of the under side slightly blotched with yellowish white. 

Skull. — Similar to that of guatemalensis but slightly smaller; 
braincase narrower: nasals slightly broader; audital bullse smaller; 
supraorbital border occasionally with a faint suggestion of a bead 
near fronto-parietal suture; palatine slits widely open; zygomata 
slightly or scarcely at all notched anteriorly; quite similar to that of 
mexicanus but teeth decidedly larger. 


Measurements. — Average of 6 adults from Volcan Irazu, Costa 
Rica: Total length, 261 (250-280) ; tail vertebrae, 130 (121-135) ; hind 
foot, 28.6 (26-30) ; ear from notch (dry), 19.1 (18.1-19.1). 

Type specimen. — No. ffff American Museum of Natural History, 
New York. 9 adult. October, 1890. George K. Cherrie. Speci- 
men in alcohol except skull, which has been removed and numbered. 
It bears a recent type label and an old label the data on which are 
illegible. The skull is broken across the frontals into two parts, but 
most of the parts important for comparison are present. 

Bernards. — In some ways this species may be said to be intermediate 
between guatemalensis and mexicanus. The most obvious character 
distinguishing it from both of these is its uniformly blackish tail. 
Occasional specimens show traces of white on the under side of the 
tail, and the known variability of this character in other species makes 
it not altogether reliable. The skull of nudipes is slightly smaller 
than that of guatemalensis but otherwise agrees very closely. It is 
about the size and often nearly the form of that of mexicanus, but 
usually there is less suggestion of supraorbital bead and the teeth are 

Specimens examined. — Total number 131, from localities as fol- 
lows : 

Chiriqui: Boquete, 89. 

Costa Rica: Azala, Cartago, 1; Carpintera, 1; El Coronet de Carrillo, 4; 

near Jiminez, 1 ; Juan Vinos, 4 ; La Estrella, Cartago, 1 ; near Sau 

Jose, 1 ; Volcan Irazu, 29. 

PEROMYSCUS FURVUS Allen and Chapman. 
(PI. V, fig. 7.) 

Peromyscus furvus Allen and Chapman, Bull. Am. Mus. Nat. Hist., N. Y., IX, 
pp. 201-203, June 16, 1897. 

Type locality. — Jalapa, Veracruz, Mexico. Altitude 4,100 feet. 

Geographic distribution. — Known from a few localities in humid 
tropical parts of northern Veracruz and Puebla. (See fig. 5, p. 161.) 

Characters.— Size slightly larger than in mexicanus (hind foot 
29-32) but smaller than in guatemalensis; color very dark; ears 
relatively small, nearly naked; tail slightly longer than head and 
body, very thinly haired, blackish all around or with slight irregular 
light markings on scaly part of under side; soles of hind feet naked 
medially to calcaneum; skull in adult with nasals widely expanded 

Color. — Slightly worn pelage: General effect of upperparts dark 
mummy brown, more blackish on dorsum and more russet on sides, 
hut dorsal area not well defined; a slight suggestion of a lateral line 
russet; sides of face brownish sepia and blackish, the blackish sur- 
rounding the eye and dominating the area from the base of the 


whiskers to the base of the ear; underparts including pectoral region 
grayish white considerably modified by slaty undercolor; forearm 
blackish brown nearly to carpal joint; fore feet white: hind feet 
white with a broad blackish brown marking on tarsal joint, this oc- 
casionally extended for some distance on upper side of hind foot : tail 
unicolor, blackish all around, or irregularly bicolor, the scaly part of 
the underside being somewhat blotched with yellowish white. Un- 
worn pelage? (No. 108540) : General effect of sides brownish sepia ; 
middle of back nearly pure black, lightly sprinkled with brownish. 

Skull. — Size slightly larger than in mexicanus, smaller than in 
guatemalensis ; frontals quite constricted and without any bead 
though the posterior part of the supraorbital border may be slightly 
sharp-angled ; zygomata slightly or not at all notched anteriorly ; 
teeth and audital bulla? moderate, slightly larger than in mexicanus 
and relatively about same size as in guatemalensis; nasals long, com- 
pressed posteriorly and exceeding ascending branches of premaxilhe, 
greatly expanded in adults anteriorly; premaxilhe correspondingly 
expanded anteriorly. 

Measurements. — Average of 14 topotypes (males) : Total length. 
2G3 (248-282) ; tail vertebra?, 131 (123-145) ; hind foot, 27.9 (26-29) ; 
ear, 21.9 (20-23). Of an adult from Huachinango, Puebla : 267; 
142; 32. 

Type specimen.— No. VoW/ American Museum of Natural His- 
tory, New York. $ adult. Apr. 2, 1897. F. M. Chapman. Speci- 
men in good condition ; tip of tail very slightly injured. 

Re marls. —The widely expanded ' bell-shaped ' nasals of this spe- 
cies are quite diagnostic, but do not develop until the animal is 
thoroughly mature. Even in young specimens, however, the nasals 
are decidedly cuneate posteriorly, and this in connection with the 
absence of any suggestion of a supraorbital bead and the very dark 
color of the pelage suffices to distinguish specimens of any age. The 
closest affinities of furvus seem to be with guatt malt ensis, although, 
save for its very dark color, it has much the general appearance of 

Specimens examined. — Total number 32, from localities, as follows: 

Puebla: Huachinango, 2. 
Veracruz: Jalapa, 2S; Jico, 2. 


Peromyscus altilaneus Osgood, Proc. Biol. Soc. Wash., XVII, pp. 74. 7.">, 'Slav. 
21, 1904. 

Type locality.— Todos Santos, Guatemala. Altitude 10,000 feet. 
Geographic distribution. — Known only from the type locality. 
Characters. — Similar to P. melanocarpus, but smaller and with 
shorter and less hairy tail; fore feet entirely white; hind feet with 


much more white than in rrielanocarpus ; skull slightly smaller and 
more slender; similar to that of guatemalensis bui much smaller. 

Co/or. — Very dark as in melanoearpus, bui tail blotched with yel- 
lowish white below, much as in mexicanus ; fore feet and part of 
forearm white; hind foot with a V-shaped dusky mark extending 
about halfway to the base of the toes, remainder of foot white; pec- 
toral spot strongly developed. 

Skull. — Similar to that of melanoearpus, but slightly smaller 
throughout; nasals relatively more expanded anteriorly; braincase 
slightly higher and more inflated and rostral region more depressed; 
anterior palatine foramina shorter; infraorbital plate very narrow; 
supraorbital bead slight; very similar to that of guatemalensis but 
decidedly smaller; similar to that of mexicanus, but smaller with a 
more depressed rostrum and a narrower infraorbital lamina. 

Measurements.— -Type: Total length, 228; tail vertebrae, 115; hind 
foot, 28; ear from notch (dry), 20.6. 

Type specimen. — No. 70856 U. S. National Museum, Biological 
Survey Collection. $ adult. Dec. 30, 1895. E. W. Nelson and E. A. 
Goldman. Specimen in good condition. 

Remarks. — This species is about the size of melanocarpus and is 
similar also in color except in extent of dusky on the feet. How- 
ever, a close study of the skulls seems to indicate that melano- 
carpus is most closely related to megalops, while altilaneus is more 
similar to guatemalensis and mexicanus. In fact, scarcely any char- 
acter can be found distinguishing it from guatemalensis except that 
of size. The type skull, that of an adult male, is so much smaller 
throughout than in typical guatemalensis that it seems hardly pos- 
sible that it is merely an abnormally small individual of that species. 
The color and character of the pelage, however, are exactly as in 

Specimen era mined. — One, the type. 

Key to subspecies of Peromyscus mexicanus. 

Size smaller; hind foot 23-24. Parts of Chiapas and Guatemala P. m. gymnotis 

Si/.!' larger; hind foot 26-29. 

Size very large; total length 244-268; hind foot usually more than 28; color 

usually very dark /'. in. totontepeeus 

Size smaller; total length 233-258; hind foot usually not more than 28. 

Color darker; rostrum and nasals heavier. Tabasco P. m. teapensis 

Color not so dark ; l-ostrum and nasals not so heavy. 

Audital bullae averaging larger. Chiapas, Guatemala, and Nicaragua. 

P. m. 8(i. r a tilts 

Audital bullae averaging smaller. Chiapas to northern Puebla. 

P. mexicanus 

(PI. V, fig. 8; PI. VII, fig. 6.) 

Hespcromys mexicanus Saussure, Rev. et Mag. de Zool., Paris, XII, pp. 103- 

105, pi. IX, figs. 1, la, Mar., 18G0. 
Pleromyscus] mexicanus Thomas, Ann. & Mag. Nat. Hist., ser. 6. XIV, p. 364, 

Nov., 1894. 


Peromyscus tehuantepecus Mefriam, Proc. Biol. Soc. Wash., XII, p. iL'i!. Apr. 
30, 1S9S. — Tehuantepec, Oaxaca. 

Type locality. — Mexico; assumed to be the vicinity of Mirador, 

Geographic distribution. — Tropical parts of eastern and southern 
Mexico from northern Puebla southward to southern Veracruz and 
thence south and east to southern Oaxaca and northern Chiapas. 

Characters. — Size medium, about as in oa.racensis, decidedly 
smaller than in megalops and guatemalensis ; tail slightly longer than 
head and body, rather coarsely annulated (about IT angulations per 
cm.) and clothed with very short scarcely obvious hairs; tail seldom 
evenly bicolor but usually blotched irregularly on the underside with 
yellowish white; ears moderate, very thinly haired; proximal fourth 
of sole of hind foot usually hairy; pelage soft but rather short; skull 
with relatively small molars and audital bullae. 

Color. — Unworn pelage : Upperparts cinnamon rufous mixed with 
dusky; middle of back darker than sides, but dusky chiefly disposed 
in fine lines and alwa} T s somewhat mixed with rufescent ; general 
effect of sides from cheeks to flanks bright russet; top of head and 
shoulders like back or slightly paler; spot at base of whiskers and 
broad orbital ring blackish brown ; underparts creamy white, with or 
without a cinnamon rufous pectoral marking; ears dusky brownish 
faintly edged with whitish; fore feet and carpal joints white; 
proximal half of forearm dusky overlaid by rufescent ; hind feet 
white, tarsal joints broadly dusky brownish; hairs of tail dusky 
above, dull white below; scaly part of tail dusky above, chiefly yel- 
lowish below, irregularly blotched with dusky. 

Worn pelage: Upperparts varying from ochraceous buff to tawny 
mixed with darker; general effect varying from dark clay color to 
russet ; middle of back usually much like sides, sometimes darker, 
approaching Mars brown and Prout brown; dusky facial markings 
much reduced in area ; underparts variously modified by slaty under- 

Adolescent pelage : Upperparts and sides pale cinnamon fawn, uni- 
formly mixed with dusky, producing a general effect varying from 

° The original description states that this species " Hahite les menies regfons 
que les precedents." "Les precedents" are H. toltecus (= Sigmodon toltecus) 
and H. fulvescens (= Oryzomys fulvescens), the first of which " Habite la Cor- 
diliere de la province de Vex-a-Cruz," and the second "Habite le Mexique." 
The description following that of mexicanus is that of H. aztecus (= Peromys- 
cus aztecus), which is said to inhabit the " Meme patrie que les precedents." 
It is evident, therefore, that Saussure did not intend to make any fine distinc- 
tions as to locality, but wished to indicate merely that all his material came 
from eastern Mexico. We are justified, then, in assuming that mexicanus 
probably came from the vicinity of Mirador, Veracruz, as Saussure is known 
to have stopped near there at the Sartorius ranch. 


wood brown to broccoli brown;- a narrow lateral line of dark ochra- 
ceous buff usually evident ; dusky orbital ring narrow, and surround- 
ing part of face slightly grayish. 

Young in lirst coat: Upperparts nearly uniform mouse gray, some- 
times paler; nearly smoke gray on sides and shoulders; and darker, 
nearly brownish slate gray, on dorsum. 

Skull. — Size medium, smaller than in megalops and gnat em ale mis, 
about equal to or slightly larger than in oaxacensis and hylo- 
eetes; rostrum and nasals moderately long; braincase usually full 
and deep but not very wide; frontals rather narrow, supraorbital 
borders sharp-angled, often with a slight bead, this usually confined 
to the vicinity of the fronto-p.crietal suture; interparietal large; 
zygoma strong, usually becoming decidedly notched anteriorly in 
adults ; molar teeth and audital bullae relatively very small ; inter- 
pterygoid fossa extending anteriorly a trifle beyond plane of last 

Measurements. — Average of four adults from Mirador, Vera- 
cruz: Total length, 246 (235-254); tail vertebra?, 128 (118-133); 
hind foot, 2G.6 (26-27); ear from notch (dry), 19 (17.7-20.5). Of 
four adults from Tehuantepec, Oaxaca : 248.5 ; 127 ; 27. 

Type specimen. — In the original description of this species, Saus- 
sure specifically mentions two specimens and gives their measure- 
ments. One of these is mounted in the Geneva Museum and was ex- 
amined some years ago by Doctor Merriam, who made the following 
notes on it and has kindly allowed their use in the present publica- 
tion : 

"No. V5 " (marked also in pencil "No. 3") Mexico. Evidently the type of 
Saussure's description and the specimen whose measurements he gave in the 
first column (p. 104). Size large; ears large; tail long and scant haired, not 
distinctly bicolor. Hind foot 26. Ear from crown 15. Tail 10G in the mounted 
specimen, the extreme tip broken off. Whiskers long, reaching shoulder. 
Texture of pelage having a velvety appearance somewhat resembling that of 
Didelphis murina. Color: Upperparts dark brown, palest on the flanks and 
cheeks, which parts are washed with pale ochraceous buff. Viewed from behind 
the dark brown of the back and shoulders seems lighter and has something of 
a hoary appearance. Just in front of the forelegs a faint fulvous wash ex- 
tends over the sides of the breast. It is probable that the colors have under- 
gone some change from museum exposure. Ankles in front and on outside dark 
brown, this color extending out on the upper surface of the feet more than half 
way to the toes ; rest of hind feet and toes white. Fore feet and wrists white, 
the brown color of the leg ending abruptly about 2 mm. above the wrist in front 
on the inner side, and 6 mm. above on the outer side. There is a little rusty 
about the nose. 

The skull of this specimen was not submitted to Doctor Merriam 
with Saussure's material, but it may be preserved still in the Geneva 
Museum, and possibly it is the one of which the teeth were figured 
with the original description. 


Remarks. — P. mexicanus and its subspecies are readily distinguish- 
able from nearly all other species by the character of the tail, which 
is very irregularly bicolor and with the scaly annulations scarcely at 
all concealed by hair. Certain larger species, as guatemalensis, sonic- 
times have irregularly blotched tails, but their size precludes the 
possibility of their being confused with mexicanus. The tail is not 
always evenly bicolor in banderanus and yucatanicus, but these forms 
are well characterized otherwise, banderanus by its beaded skull and 
yucatanicus by its small size. The subspecies of mexicanus are very 
slightly characterized and perhaps but recently developed from a 
common stock. They can not consistently be ' lumped,' but it must be 
said that there is much variation throughout the group and that none 
of the characters of the several subspecies are absolutely constant. 
Certain average characters, however, are to be found, and certain ex- 
tremes of differentiation are fairly marked. The variation in cranial 
characters is very great, and every considerable series examined has 
shown some deviations from the general type. It is difficult to asso- 
ciate any two series on the basis of common peculiarities. In view of 
this variation it does not seem possible to recognize a form under the 
name ' tehuante peats.'' The small series from Tehuantepec are chiefly 
in worn pelage and in color do not differ from similarly worn speci- 
mens from localities in Veracruz near the type locality of mexicanus. 
Although the interparietal averages large in the few skulls from 
Tehuantepec, it does not seem to be a subspecific character, for equally 
large interparietals may be found in almost any series; in fact, the 
most nearly perfect skull from Mirador, the type locality of mexi- 
canus, has the interparietal slightly larger than that of the type of 
' tehuantepecus. 1 In regard to color there is also much variation, 
perhaps of an ' ontogenetic ' nature. Specimens from more humid 
localities are usually darker than those from more arid parts, but this 
does not seem to be correlated with definite areas. It is even conceiv- 
able that unusual darkness of color may be produced by an unusually 
wet season in a normally arid region. 

Specimens examined. — Total number 182, from localities as fol- 

Chiapas: Mountains near Tonala, 8; Ocozucuautla, 4; Ocuilapa, 2; Val- 
ley of Jiquipilas, 4. 

Oaxaca: Agua Frio, 7; Lagunas, 3; near Tehuantepec, 5; Santa Eflgenia, 

Puebla: Metlaltoyuca, 7. 

Veracruz: Achotal, 19; Carrizal, 9; Catemaco, 5; Jieo, 12; Lagunas, 6; 
Mirador, 4; Otatitlan, 4; Papantla, 13; Pasa Nueva, 8; San Andres 
Tuxtla, 4; San Carlos, 12; Santiago Tuxtla, 9; Teoeelo, 2 (approach- 
ing totontepecus) ; Texolo, 16; Volcan Tuxtla, (approaching 



Peromyscu>8 mexicanus totontepecus Merriam, Proc. Biol. Soc. Wash., XII, pp. 

120-121, Apr. 30, 1898. 
Peromyscus mexicanus orizabae Merriam, supra cit., pp. 121-122. — Orizaba, 

Veracruz, Mexico. 

Type locality. — Totontepec, Oaxaca, Mexico. Altitude, 6,000 feet. 

Geographic distribution. — Western Veracruz and east central 
Oaxaca west of the range of P. mexicanus. 

Characters. — Similar to P. mexicanus, but larger and averaging 
decidedly darker; skull larger and molar teeth heavier. 

Color. — Similar to that of mexicanus, but darker throughout; gen- 
eral effect of back Prout brown nearly to black; general effect of 
sides cinnamon rufous to chestnut ; dusky markings accentuated, 
those on the tarsal joints extending from one-third to one-half the 
length of the upper side of the hind foot; pectoral spot more fre- 
quently and more extensively developed than in mexicanus,' entire 
underparts often suffused with rufescent. 

Skull. — Similar to that of mexicanus, but averaging larger; molar 
teeth larger and broader. 

Measurements. — Average of 5 adult topotypes: Total length, 257 
(244-208) ; tail vertebra?, 131 (124-136) ; hind foot, 28.2 (28-29) ; 
ear from notch (dry), 16.9 (16-17.8). Average of 10 adults from 
Orizaba, Veracruz: 254 (238-269); 134 (122-142); 28.6 (28-29.5). 

Type specimen. — No. 68624 U. S. National Museum, Biological 
Survey Collection. 9 adult. July 16, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in good condition; skull with slightly 
broken basioccipital. 

Remarks. — This form is distinguished from mexicanus and the 
others of the group chiefly by its large size. It is also very dark 
colored, but is nearly equaled in this respect by teapensis, though 
quite decidedly darker than mexicanus or saxalilis. Skulls from 
Totontepec do not show such heavy and deeply notched zygomata as 
those from Orizaba, but after considering the entire mexicanus group, 
it appears that this and other peculiarities found in small series from 
various localities are due to age or individual variation. The dark 
color, large size, heavy skull, and relatively broad molars seem to be 
the only characters common to series from more than one locality, 
and therefore the series with these associated characters have been 
recognized under the name totontepecus without regard to the pecul- 
iarities of individual series which are not constant and are found 
sporadically throughout the group. The apparent tendency of the 
series from Orizaba to heavy notched zygomata may be indication 
of a leaning towards mexicanus, for the best available adult skull of 
typical mexicanus from Mirador shows exactly this type of zygoma. 
It is strange that these Orizaba specimens should differ at all from 


those of mexicanus, for the locality is on the same mountain slope but 
a short distance from Mirador. 
Specimens examined. — Total number 71, from localities as follows: 

Oaxaca: Choapam, 1 : " Comaltepec, 2; Guichicovi, 8; a mountains near 

Santo Domingo, 0; " Santo Domingo, 13; a Totontepec, 10. 
Veracruz: Motzorongo, 11; Orizaba, 20/' 


Peromyscus mexicanus saxatilis Merriam, Proc. Biol. Soc. Wash., XII, p. 121, 

Apr. 30, 1898. 
Peromyscus nicaraguae Allen, Bull. Am. Mus. Nat. Hist, XXIV, pp. 649-650, 

Oct. 13, 1908.— Matagalpa, Nicaragua. 

Type locality. — Jacaltenango, Huehuetenango, Guatemala. Alti- 
tude, 5,400 feet, 

Geographic distribution. — Northwestern Guatemala and southeast- 
ern Chiapas, south to Nicaragua. 

Characters. — Very similar to mexicanus / color practically identical; 
skull with slightly larger audital bulla?. 

Color. — As in mexicanus. 

/Skull. — Similar to that of mexicanus; braincase averaging broader 
and fuller; frontals wider with slightly less tendency to the forma- 
tion of a supraorbital bead ; audital bulla? larger. 

Measurements. — Average of 10 adult topotypes: Total length, 224 
(233-258); tail vertebra?, 127 (120-138); hind foot, 27.6 (27-29); 
ear from notch (dry), 18.2 (16.6-19.5). 

Type specimen. — No. 77296 U. S. National Museum, Biological 
Survey Collection. $ adult. Dec. 19, 1905. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. Size abnormally 

Remarks. — The only character of consequence by which to separate 
this form from mexicanus is the size of the audital bulla 1 , and even 
this is not absolutely constant. As an average character, however, 
it seems to prevail throughout a considerable number of specimens 
from several localities. The recognition of this form makes it even 
more imperative to place ' tchuantepecus ' in synonymy, for it seems 
that the Tehuantepec specimens are intermediate between mexicanus 
and saxatilis in much the same way that Orizaba specimens fall 
between mexicanus and totontepecus. In color saxatilis seems to be 
exactly like mexicanus. The series from Jacaltenango are in unworn 
pelage exactly like specimens in the same pelage from Mirador. The 
worn pelage is shown by specimens from Canjob and San Bartolome, 
wdiich agree with equally worn specimens of mexicanus from locali- 
ties in Veracruz. The type of saxatilis is unusually small, the skull 

a Approaching mexicanus. 


and teeth being particularly .small and light as compared with those 
of the large series of topotypes. 
Specimens examined. — Total number 96, from localities as follows: 

Chiapas: Canjob, 1G; Cliicharras, 20 (approaching gymnotisf) ; San 

Bartolorne, 7; San Vicente, 1; Tuxtla (Jutierrez, 4. 
Guatemala: Jacaltenango, 34; Xenton, 4. 
Nicaragua: Ohontales, 3; Matagalpa, 5; San Rafael del Norte, 2. 


Peromyscus mexicanus tcapensis Osgood, Proc. Biol. Soc. Wash.. XVII, pp. 
G9-70, Mar. 21, 1904. 

Type locality. — Teapa, Tabasco, Mexico. Altitude 800 feet. 

Geographic distribution. — Humid tropical parts of northern 
Tabasco, Mexico. 

Characters. — Similar to P. m. totontepecus, but sides brighter and 
more contrasted with dark area in middle of back ; skull with thicker, 
heavier rostral region. 

Color. — Type : Sides rich chestnut, shading into a well-defined 
blackish area in median dorsal region; a narrow black orbital ring 
and spot at base of whiskers; underparts slate color overlaid with 
creamy Avhite (no pectoral spot in type, but of frequent occurrence 
among series of topotypes) ; tail black with the exception of a few 
irregular spots of yellowish white on under side; fore feet white; 
hind feet white except a dark brown area extending with decreasing 
width from ' ankles ' down nearly to base of toes. 

Skull. — Similar to that of totontepecus, but with broader nasals 
and generally heavier and more thickened rostral region; anterior 
palatine foramina usually wider; infraorbital part of zygomata rather 
heavy but not squarely 'elbowed'; teeth about as in totontepecus^ 
wider and heavier than in mexicanus. 

Measurement*. — Average of 10 adults from the type locality: Total 
length. 245 (234-254); tail vertebras, 129 (121-136); hind foot, 28 

Type specimen. — No. 100022 U. S. National Museum, Biological 
Survey Collection. ? adult. March 25, 1900. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — The thickened rostrum and anteriorly expanded nasals 
of this form approach the condition found in P. furvus, but the de- 
velopment is not so extreme as in that species. As in furvus, the 
characters are not well developed except in fully adult specimens. 
The vicinity of Teapa, visited by Nelson and Goldman in the spring 
of 1900, is not far above sea level, and is now well known for the 
dark rich color of its animals. The present subspecies is not an ex- 
ception. Its color is not so extensively blackish as in totontepe< u*. 
but the rufescent shades equal in richness anything found elsewhere 
in the mexicanus group. 


Specimens examined. — Total number 21, from localities as follows: 
Tabasco: Near El Salto, 2: Monteeristo, 2; Tea pa, 17. 


Peromyscus gymnotis Thomas, Ann. & Mag. Nat. Hist., Loud., ser. <>, XIV, pp. 

365-36G, Nov., 1894. 

Type locality. — Guatemala. 

Geographic distribution. — Certain parts of Guatemala and (prob- 
ably) northward at slight elevations to southwestern Chiapas. 

Characters. — Similar to /'. mexicanus, but smaller (hind foot 23- 
25) ; tail about equal to or slightly shorter than head and body, 
scaly annulations slightly finer than in mexicanus and clothed with 
even shorter hairs; tail nearly unicolor or with slight blotches of 
yellowish on under side; ears moderate, very scantily haired. 

Color. — No. 77659: Upperparts chiefly rich tawny ochraceous. al- 
most as in P. astecus, except that there is very little black in the 
mid-dorsal region ; underparts dull buffy white with slaty under- 
color showing through, pectoral region suffused with fulvous; head, 
feet, and ears about as in mexicanus ; scaly part of tail dusky black- 
ish all around except some slight blotches of yellowish white on 
proximal half of under side. Two additional specimens in worn 
pelage : Back dark mummy brown with thin patchy areas of ochra- 
ceous on the sides. 

Skull. — Similar to that of mexicanus but smaller, about the size 
of that of P. aztecus; premaxillse rather swollen laterally; nasals 
decidedly convex; zygomata depressed anteriorly considerably below 
plane of rostrum; supraorbital border with a very slight suggestion 
of a bead; teeth and audital bulla? small. 

Measurement*. — Tj^pe and two adults from Huehuetan, Chiapas, 
respectively: Total length, 191: 217: 220; tail vertebra?, 92; 101; 
110; hind foot, 23; 25; 24; ear from notch, 17; 16.5 (dry) ; 15 (dry). 

Type specimen. — No. British Museum. " Coll. Bernoulli.'' 
Specimen in alcohol in fair condition. 

Remarks. — The above description is based chiefly on three speci- 
mens from Huehuetan, Chiapas, which are believed to be very similar 
to the type of P. gymnotis. Two of these specimens (Nos. 77658 and 
77659) were sent to the British Museum in the summer of 1905 and 
there compared by G. S. Miller, jr.," with the type of gymnotis. 

Mr. Miller's notes on the type are as follows : 

Color of type injured by alcohol— a peculiar indefinite gray brown above, sug- 
gesting immaturity — underparts between buff and Isabella color — no pectoral 
spot visible. Tail of type more finely ringed than in any of these, 22 rings 
to the centimeter at middle and without trace of lighter color below — haired as 

"Since the above was written I also have examined this type, but can form 
uo more positive conclusions regarding it than those here stated. 


in Nos. 77658 — cars as in 77658-9. The animal is close to these (judging by 
externals) and not at all like 77309 [sa.mtilis\, which is much too large and 
with bicolor tail. 

In spite of this fairly close agreement there are some discrepancies, 
and it is quite possible that additional collecting- in Guatemala may 
prove either that gymnotis is the same as allophylus or a species not 
yet represented in American collections. For the present it seems 
best to associate the name gymnotis with the specimens from Huehue- 
tan rather than to add another name to a difficult group already over- 
burdened. The essential part of the original description of gymnotis 
is as follows: 

Si/.c medium; ears long, tail short. General color, so far as can be made out 
in a spirit-specimen, very dark, almost bistre-brown. Under surface dirty buff, 
the slate-colored bases of the hairs showing through. Ears long, laid forward 
in a spirit-specimen they reach 3 or 4 millim. in front of the anterior canthus 
of the eye; perfectly naked, no hairs being discernible upon (hem (except at 
their bases posteriorly) even with a lens; 1 their substance plumbeous in color. 
Palate ridges 3-5. Hands and feet thinly covered with fine silvery-white hairs; 
fifth bind toe reaching to the base of the second phalanx of the fourth; soles 
practically naked along median line, a few scattered white hairs being only 
found on this part. Tail slightly shorter than the head and body, slender, 
very thinly clothed with minute brown hairs, which are everywhere of the 
same color, while the skin of the tail itself is also dark brown above and 
below for its whole length. 

Skull, as compared to that of P. aztccus, decidedly more lightly built and 
flatter above when viewed in profile; muzzle longer and narrower; supra- 
orbital edp's square but not beaded ; palatal foramina widely open; bulla? rather 
smaller. Dimensions of the type (an adult male in spirit) : Head and body 99 
millim.; tail 92; hind foot 22 (with claws 23) ; ear 17 x 13.5; heel to front of 
last footpad 10. 

Specimens examined. — Total number 4, from localities as follows: 

Chiapas: Huehuetan, 3. 
Guatemala: Guatemala, 1 (type). 


Peromyscus allophylus Osgood, Proc. Biol. Soc. Wash., XVII, p. 71, Mar. 21, 

Type locality. — Huehuetan. Chiapas, Mexico. Altitude 200 feet. 

Geographic distribution. — Known only from the type locality. 

Characters. — Size medium (hind foot '25) ; tail shorter than head 
and body; ears moderate, scantily haired; coloration dark: tail dusky 
blackish, unicolor, covered with small imbricate scales, much as in 
Oryzomys; proximal third of soles of hind feet finely haired; skull 
rather long and narrow ; teetli very small. 

1 "A second examination with a more powerful lens shows that there are a 
few widely scattered minute whitish hairs on the ears, but they are so few and 
so small as practically not to affect the statement in the text." 


Color. — General effect of sides mummy brown, deepening toward 
middle of back, causing a rather distinct median dorsal line of 
blackish brown; underparts yellowish white over slate-color, the 
latter showing through; tail dusky blackish, unicolor; a black orbital 
ring and antorbital spot; feet whitish, scantily haired; 'ankles' 

Skull. — Rather long and narrow ; braincase elevated ; infraorbital 
notch scarcely evident ; nasals rather short, slightly exceeded by 
premaxillae; no supraorbital ridge; palatine foramina rather large, 
longer than bony palate; audital bullae small, smaller than in aztecus 
or mexicamis and having a marked flange on anterior flattened pro- 
duction; molar teeth very small; interparietal small; frontals rather 
wide; supraorbital border sharp-angled but not beaded. 

Measurements. — Type: Total length, 202; tail vertebrae, 95; hind 
foot, 2o; ear from notch (dry), 17. 

Type specimen. — No. 77657 U. S. Xational Museum, Biological 
Survey Collection. 9 adult. Feb. 21, 1896. E. W. Nelson and E. A. 
Goldman. Specimen in good condition. 

Remarks. — It is difficult to be certain of the affinities of this pecu- 
liar species. But for the size of its ears and shortness of its tail it 
might well pass for an Oryzomys of the O. chapmani group. Its 
dark scaly tail suggests Oryzomys, and the character and color of its 
pelage bear out the resemblance. Its skull, however, is that of the 
ordinary type of Perom.yscus. Its closest relationship is probably 
with the mexicanus group, though it may be a northern member of 
a Central American group not yet known as such. It agrees in some 
respects with the description of P. gymnotis Thomas from Guate- 
mala, but without direct comparison it is difficult to determine 
whether or not it is that species. 

Specimen examined. — One, the type. 

Key to Subspecies of Peromyscus banderanus. 

Skull with supraorbital beads slight or obsolete /'. b. angelensis 

Skull with supraorbital beads well developed. 

Color paler, chiefly ochraceous buff with very little dusky mixture /'. banderanus 

Color darker, usually with considerable mixture of dusky P. h. vicinior 


(PI. V, fig. 1.) 

Peromyscus banderanus Allen, Bull. Am. Mus. Nat. Hist.. X. V„ IX, p. 51, 
Mar. 15, 1897. 

Type locality. — A r alle de Banderas. Tepic, Jalisco, Mexico. 

Geographic distribution. — Pacific coast of Mexico from Bahia 
Banderas. Tepic, to vicinity of Acapulco, Guerrero. 

Characters. — Size medium (hind foot about 25) ; tail about equal 
to head and body; ears moderate; pelage soft but rather short; soles 


of hind feet naked to calcaneum; color chiefly bright ochraceous buff; 
skull rather elongate and having well-developed supraorbital beads. 

Color. — No. \\\%% Hacienda Magdalena, Colima, Mar. 19, pelage 
very slightly worn: General color of upperparts and sides ochra- 
ceous buff, with a very fine mixture of cinnamon nearly uniformly 
distributed; the color is almost solid ochraceous buff, being merely 
toned down by the admixture of cinnamon tipped hairs and the effect 
of the underlying plumbeous; underparts creamy with a broad 
ochraceous buff pectoral patch ; forehead and sides of head mixed 
cinnamon and drab gray; a buffy spot under eye connecting on its 
lower side with the main color of the sides; orbital ring and spot at 
base of whiskers Vandyke brown; feet white with a prominent spot 
of Prout brown on 'ankles': hairs of tail dusky above, white below, 
scaly part of tail sometimes bicolor, but frequently blotched dusky 
tmd yellowish. Adolescent, No. 70757, Acapulco, Guerrero: Similar 
to adult, but general color decidedly paler and more broken up by 
admixture of dusky tipped hairs with a slight tendency to concen- 
tration in median dorsal region. Young: Underfur slate color 
(Ridgway, PL II, No. 4), as in adults; ground color smoke gray with 
a plentiful mixture of brownish tipped hairs; dusky markings about 
eyes, whiskers, and ' ankles ' well indicated. 

Skull. — General outline narrow and elongate; posterior part of 
braincase elongated to such extent that more than half of the large 
interparietal lies posterior to a plane passing behind the audital 
bulla 1 ; supraorbital beads highly developed, forming a trenchant shelf 
above the orbit and bounded on the inner side by a distinct groove- 
like channel extending from the lacrymal region up to and often 
be} T ond the parieto- frontal suture; lacrymal region swollen; nasals 
ending slightly anterior to a well-marked interlacrymal pit and 
almost exactly on the plane of the anterior border of the orbit ; audital 
bulla 1 rather small (scarcely more than half as large as in mela- 
nophrys) ; anterior palatine foramina smaller than in mexicanvs or 
melanophrys, and usually ending anterior to the plane of the front 
of the first upper molar; general shape of these foramina usually tri- 
angular, being narrowest at the anterior apex and gradually widen- 
ing to the middle and thence nearly constant to the posterior end; 
teeth of moderate size, slightly smaller than in mexicanus and melan- 

Measurements. — Average of 5 adults from Hacienda Magdalena, 
Colima: Total length, 234 (228-245); tail vertebra, 119 (115-127); 
hind foot, 25; ear from notch (dry), 18 (17.2-18.5). 

Type specimen. — No. WW American Museum of Natural History, 
New York. ? adult. Feb. 23, 1893. A. C. Buller. Skin in 
good condition, though badly formed, head ' humped,' forelegs turned 


back, etc. Skull with nasals slightly chipped in front, molar teeth 
loose and two of them missing; otherwise in good condition. 

Remarks. — P. banderanus is about the size and proportions of P. 
aztecus and closely related forms, but is much paler in color. Its 
naked soles distinguish it from this and all other Mexican species of 
approximate size. Its general combination of characters is unique, 
so it should not be confused with other species. The naked soles, 
pale color, and narrow beaded skull easily distinguish it. It is con- 
fined to the west coast of Mexico and has but two subspecific repre- 
sentatives, one at the extreme southern end of its range and the other 
a short distance into the interior to the eastward. 

Specimens examined. — Total number 41, from the following lo- 
calities in Mexico : 

Colima: Colima City, 7; Hacienda Magdalena, 9; Hacienda San Antonio, 

1 ; Manzanillo, 7. 
Guerrero: Acapulco, 11; El Limon, 2; near Ometepec, 2. 
Tepic: Navarrete, 1; Valle de Banderas, 1. 


Peromyscus banderanus vicinior Osgood, Proc. Biol. Soc Wash., XVII, pp. 68- 
69, Mar. 21, 1904. 

Type locality. — La Salada, Michoacan, Mexico. 

Geographic distribution. — Western Mexico in the States of Michoa- 
can and Guerrero, occupying the slightly more elevated region imme- 
diately east of the range of typical banderanus. 

Characters. — Similar to P. banderanus but darker, usually with 
considerable mixture of dusky in color; skull averaging narrower; 
soles of hind feet naked medially. 

Color. — Slightly darker and more vinaceous in worn pelage than in 
banderanus,' decidedly darker in winter pelage; ground color ochra- 
ceous buff, but with a strong mixture of dusky on back and sides and 
a slightly differentiated concentration in median dorsal region ; nose 
and sides of face grayish ; markings about eyes, whiskers, and tarsal 
joints sooty instead of brownish ; pectoral spot often absent ; upper 
side of tail blackish instead of brownish; otherwise similar to 

/Skull. — Similar to that of banderanus, but braincase averaging 
slightly narrower; anterior palatine foramina more nearly elliptical, 
being widest in the middle and narrowing toward each end; supra- 
orbital beads well developed. 

Measurements. — Type: Total length, 216; tail vertebrae, 107; hind 
foot, 27. Average of three adolescents from La Huacana, Michoa- 
can: 233 (225-240); 117 (115-121); 24.5 (24-25); ear from notch 
(dry), 16.2 (16-16.5). 

66268— No. 28—09 14 


Type specimen. — No. 126503 U. S. National Museum, Biological 
Survey Collection. $ adult. March 23, 1903. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — This is an interior form of banderanus having a narrow 
range in the slightly elevated region paralleling the coast. In full 
unworn pelage, as shown by two specimens from Los Reyes, Michoa- 
can, it is decidedly darker than banderanus, since the pelage contains 
a liberal mixture of dusky. The small series from La Salada have 
uniformly narrow skulls, noticeably narrower than in banderanus, 
but other specimens from Los Reyes and La Huacana indicate that 
this character is not stable. Whether it is even an average character 
throughout the range of the form will appear when further material 
is acquired. 

Specimens examined. — Total number 15, from localities as follows: 

Guerrero: Acahuizotla, 3. 

Michoacan: La Huacana, 4; La Salada, 6; Los Reyes, 2. 


Peromyscus banderanus angelensis Osgood, Froc. Biol. Soc. Wash., XVII, p. 69, 
Mar. 21, 1904. 

Type locality. — Puerto Angel, Oaxaca, Mexico. 

Geographic distribution. — Coast of southern Oaxaca; known from 
two localities only. 

Characters.- — Similar to typical banderanus; size larger; sole of 
hind foot narrowly naked medially, but not so obviously so as in 
banderanus; skull larger and heavier; supraorbital bead nearly 
obsolete instead of well-developed. 

Color. — Practically as in banderanus ; possibly averaging a trifle 
darker; pectoral spot well-developed and considerably produced 

Skull. — Similar in general form to that of banderanus, but supra- 
orbital borders much less distinctly or scarcely at all beaded, but 
reduced to simple shelves much as in melanophrys and mexicanus; 
size larger; braincase less elongate; interparietal shorter; nasals 
longer ; molar teeth slightly larger. 

Measurements. — Average of 7 adult topotypes: Total length, 235 
(222-258) ; tail vertebra?, 120 (112-128) ; hind foot, 27 (26.5-28) ; ear 
from notch (dry), 17.3 (17-17.7). 

Type specimen. — No. 71442 U. S. National Museum, Biological 
Survey Collection. 9 adult. March 13, 1895. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — The divergence of this form from typical banderanus 
seems to be in the direction of the mexicanus group. Its general 
appearance, character of pelage, nearly naked soles, etc., are as in 
banderanus, but its skull approaches that of mexicanus quite closely, 


differing mainly in its more elongate braincase. Therefore, it would 
not be surprising - if further material should demonstrate connection 
between mexicanus and banderanus. 

Specimens examined. — Total number 23, from localities as fol- 

Oaxaca: Pinotepa, 1 : Plunia, 2; Puerto Angel, 20. 

Key to Subspecies of Peromyscus yucatanicus. 

Color paler, not largely mixed with dusky ; median dorsal area usually not differen- 
tiated P. yucatanicus 

Color darker, with considerable mixture of dusky ; dorsal area usually somewhat differ- 
entiated P, y. badius 


(PL V, fig. 4.) 

Peromyscus yucatanicus Allen and Chapman, Bull. Am. Mus. Nat. Hist., N. Y., 
IX, p. 8, Feb. 23. 1897. 

Type locality. — Chichenitza, Yucatan, Mexico. 

Geographic distribution. — Northern parts of the peninsula of Yu- 
catan ; chiefly arid tropical zone. 

Characters. — Size medium (hind foot 22-24) ; tail about equal to 
or slightly shorter than head and body ; ears medium, nearly naked ; 
soles of hind feet hairy proximally; tail thinly haired, scarcely pen- 
ciled, evenly bicolor or with under side blotchy; skull with slight 
supraorbital bead, small teeth, and small audital bulla?. Similar in 
general characters to P. mexicanus, but decidedly smaller. 

Color. — Slightly worn pelage: Upperparts bright ochraceous buff 
or ochraceous, lightly and nearly uniformly mixed with dusky ; sides 
about like back; a rather broad lateral line clear ochraceous, only 
slightly contrasted; a narrow dusky orbital ring; underparts yellow- 
ish white, becoming more nearly pure white on throat and chin; pect- 
oral spot rarely present; feet white, tarsal joint slightly marked 
with pale brownish ; hairs of tail dusky above and white below, 
evenly divided, but scaly annular part of tail dusky above and yel- 
lowish white below, variously speckled and blotched with dusky. 

Skull. — Size medium; braincase rather elongate; frontals wide and 
supraorbital border shelflike or slightly beaded; nasals relatively 
wide, ending about even with posterior endings of premaxilla?; au- 
dital bulla? medium or rather small; palatine slits moderately large; 
teeth relatively very small; zygomata very slightly notched by infra- 
orbital foramina. Similar in general to that of mexicanus, but very 
decidedly smaller throughout. 

Measurements. — Average of 10 adults from La Vega, Yucatan: 
Total length, 216 (208-232) ; tail vertebra?, 112 (105-122) ; hind foot, 
23.8 (23-26) ; ear from notch (dry), 17 (15.2-18.3). 


Type specimen. — No. iff |{ American Museum of Natural History, 
New York. $ adult. Mar. 17, 1896. Frank M. Chapman. Speci- 
men in good condition. 

Remarks. — While apparently quite distinct, this species is little 
more than a miniature of P. mexicanus. In all general characters 
except size it shows no marked departure from mexicanus. Its slightly 
blotched tail, slightly headed skull, small teeth, and small audital 
bullae readily distinguish it from any species approximating it in 
size. Its pelage, including the hairiness of the tail, is not so coarse 
as in mexicanus, and in specimens so far examined (all in slightly 
worn pelage) the color is somewhat ^brighter, being chiefly bright 
ochraceous throughout. 

Specimens examined. — Total number 35, from localities as follows: 
Yucatan: Chichenitza, S ; La Vega, 26 ; Puerto Morelos, 1. 


Peromyscus yucatanicus badius Osgood, Proc. Biol. Soc. Wash., XVII, pp. 70-71, 
March 21, 1904. 

Type locality. — Apazote, Campeche, Mexico. 

Geographic distribution. — Known only from the type locality. 

Characters. — Similar to P. yucatanicus, but darker colored. 

Color. — Decidedly darker than P. yucatanicus^ having the median 
dorsal area with a strong admixture of black and more or less black 
on the sides, except a narrow lateral line which is cinnamon rufous 
like the general ground color; underparts faintly suifused with yel- 
low; a narrow black orbital ring; hairs of tail blackish brown above, 
white below; underside of tail beneath hairs chiefly yellowish white, 
but somewhat irregularly blotched with dusky; feet white. 

Skull. — As in /'. yucatanicus. 

Measurements. — Average of 10 topotypes: Total length, 193.4; tail 
vertebra?, 96.7; hind foot, 23.5; ear from notch (dry), 16.4 (16-16.8). 

Type specimen. — No. 108016 U. S. National Museum, Biological 
Survey Collection. 9 adult. Dec. 28, 1900. E. W. Nelson and E. A. 
Goldman. Specimen in good condition. 

Remarks. — This slight form doubtless owes its dark color to the 
character of its habitat, which is in a more humid region than that 
of true yucatanicus. Its range is probably limited to the region of 
the base of the peninsula of Yucatan, as its nearest relatives known 
from Avest of that region are the larger and quite different forms of 
the mexicanus group. 

Specimens examined. — Total number 19, all from the type locality. 

Key to subspecies of Peromyscus meg-alops. 

Tail uniform blackish all around P. m. mchinurus 

Tail evenly bicolor or at least somewhat blotched with yellowish white below. 

Slightly darker; audital bulhv smaller P. megalops 

Slightly paler ; audital hullaj larger-^ ^_, , ,_, P. m. auritus 



( PI. V, fig. 5. i 

Peromyscus megalops Merriam, Proc. Biol. Soc. Wash.. XII, p. 119, Apr. 30, 


Type locality. — Mountains near Ozolotepec, Oaxaca, Mexico. Alti- 
titude, 10,000 feet. 

Geograj)hic distribution. — Known only from the type locality. 

Characters — Size large (hind foot 30-31) ; tail decidedly longer 
than head and body, coarsely haired, and irregularly bicolor; pelage 
long and lax; color with more tawny than in guatemalensis, much 
as in tlwmasi; skull with large broad braincase and distinct supra- 
orbital bead. 

Color. — Slightly worn pelage: Upperparts mixed tawny and 
blackish brown ; sides chiefly rich tawny but little modified by dusky ; 
broad dorsal area chiefly blackish brown, lightly sprinkled with tawny, 
producing a general effect approaching the mummy brown of Kidg- 
Avay; line from base of whiskers to and around eye and thence half- 
way to base of ear broadly blackish brown; forehead brownish; sides 
of nose in front of whiskers grayish cinnamon ; extreme tip of nose 
with a tiny whitish spot ; underparts pale whitish buff, somewhat 
modified by undercolor; pectoral and axillary region broadly tawny 
(usually) ; feet white; forearm with a narrow dusky line reaching 
nearly to carpal joint ; tarsal joint broadly dusky, and this sometimes 
slightly extended on upper side of hind foot ; hairs of tail usually 
evenly bicolor, dusky above, whitish below; scaly annular part of tail 
dusky above and irregularly blotched dusky and yellowish white 

Skull. — Size large, exceeding that of mexicanus and about equaling 
that of guatemalensis; braincase broad; frontals broad, distinctly 
beaded on supraorbital border and depressed in median line forming 
a shallow pit immediately behind the nasals; lacrvmal region rather 
swollen ; zygomata very slightly notched by infraorbital foramina ; 
nasals rather long, slightly exceeding the ascending branches of the 
premaxillse; audital bullae relatively small; interpterygoid fossa 
wide and long, extending anteriorly to the plane of the middle of the 
last molar; palatine slits large and broadly open; teeth moderate, 
decidedly larger than in mexicanus, about as in guatemalensis. 

Mi asurements. — Type: Total length, 282; tail vertebra 1 , 150; hind 
foot, 31'; ear from notch (dry), 19. Average of five topotypes: 278; 
147; 31. 

Type specimen. — No. 71592 U. S. National Museum, Biological 
Survey Collection. $ old. March 26, 1895. E. W. Nelson and E. A. 
Goldman. Specimen in good condition, but skull lacking the first 
upper molar on each side. 


Remarks. — This species and its very closely allied subspecies are 
among the largest members of the restricted genus. They about 
equal guatemalensis in size, and in the subgenus Peromyscus are ex- 
ceeded only by P. zarhynchus. They may be distinguished from 
guatemalensis by their more tawny color and by their more distinctly 
beaded frontals. 

Specimens examined. — Total number 5, all from the type locality. 


Peromyscus auritus Merriam, Proc. Biol. Soc. Wash., XII, pp. 119-120, Apr. 30, 

Peromyscus comptus Merriam. supra cit., p. 120. — .Mountains near Chilpancingo, 

Type locality. — Mountains 15 miles west of Oaxaca, Oaxaca, Mex- 
ico. Altitude 9,300 feet. 

Geographic distribution. — High altitudes in mountains of western 
Oaxaca and southeastern Guerrero, Mexico. (See fig. 5, p. 161.) 

Characters. — Very similar to P. megalops, but ears possibly slightly 
larger and color averaging slightly paler; audital bulla? decidedly 

Color. — Practically as in megalops, but apparently averaging 
slightly paler. Unworn pelage: General effect of upperparts cinna- 
mon; back only very slightly darker than sides; face with dusky 
markings subdued by fulvous, only a narrow orbital ring conspicuous; 
underparts nearly pure creamy white, but slightly modified by under- 
color ; tail dusky above, white below, scaly part very slightly blotched 
with dusky on underside. Worn pelage: About as in megalops; dark 
undercolor more exposed on upperparts as well as on underparts; 
sides of face darker, with dusky markings more pronounced. 

/Skull. — Similar to that of megalops, but audital bulla? decidedly 
larger; nasals slightly longer. 

Measurements. — Type: Total length, 288; tail vertebra?, 148; hind 
foot, 30.5; ear from notch (dry), 23.3. Average of four topotypes: 
281; 148; 31.5. Of ten adults from mountains near Chilpancingo, 
Guerrero (' comptus'): 273; 143; 30.4. 

Type specimen. — No. G8438 U. S. National Museum, Biological 
Survey Collection. 9 old. Sept. IT, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — In all general characters this form is like megalops. 
Its best distinguishing character is the size of the audital bullae, which 
is markedly greater than in megalops. The material thus far avail- 
able in this small group is hardly sufficient for satisfactory conclu- 
sions as to slight variations in color. The few specimens of auritus 
from the type locality are in somewhat worn pelage. A considerable 
series of adults from the mountains near Chilpancingo, Guerrero, are 


in very full unworn pelage, which appears to be quite decidedly 
lighter than the worn pelage. Their subspecific separation would 
seem to be warranted were it not for a series recently obtained from 
Omilteme, Guerrero, but a few miles away, in which are found 
slightly worn specimens indistinguishable from the type of auritus. 
The ears appear to be slightly larger than in megalops, but with only 
dry specimens for comparison it is difficult to be certain of the real 
difference in this respect. 
/Specimens examined. — Total number 38, from localities as follows : 

Guerrero: Mountains near Chilpancingo, IS; Omilteme, 14. 
Oaxaca: Mountains 15 miles west of Oaxaca, 6. 


Type from Pluma, Oaxaca, Mexico. Altitude, 4,600 feet. No. 71385, U. S. 
National Museum. Biological Survey Collection. $ adult. Mar. 20, 1895.. 
E. W. Nelson and E. A. Goldman. 

Geographic distribution. — Known only from the type locality. 

Characters. — Similar to megalops, but size smaller, pelage much 
shorter, and skull smaller and more stoutly built ; tail nearly unicolor, 
blackish above and below. Size and general appearance about as in 
mexicanus, but skull with broader and more distinctly beaded frontals. 

Color. — Worn pelage: Extremely variable, running from Mars 
brown to bright tawny ochraceous; a dark dorsal area considerably 
darker than sides usually well marked; dusky orbital ring and spot 
at base of whiskers sharply defined ; feet white, thinly haired, broadly 
brownish on tarsal joints: underparts yellowish white, usually with- 
out fulvous pectoral area : tail blackish all around, scaly part some- 
times with indistinct zones of dull yellowish brown at irregular in- 
tervals in its length. 

Skull. — Similar to that of megalops, but slightly smaller and more 
stoutly built; rostrum thicker: teeth and audit al bullae smaller; 
interparietal large and quite produced posteriorly ; frontals wide 
and distinctly beaded ; anterior part of zygomata scarcely or not 
at all notched by infraorbital foramen. Somewhat similar to that 
of mexicanus but larger; frontals wider and more distinctly and 
extensively beaded; teeth larger; audital bullae about same size. 

Measurements. — Average of 10 adult topotypes: Total length. 259 
(238-278) ; tail vertebrae, 135 (127-145) ; hind foot, 27.3 (26-28.5) ; 
ear from notch (dry), 17 (15.8-17.8). 

Remarks. — This form shows quite a marked departure from mega- 
lops in size and external appearance, but since it agrees with it 
closely in cranial characters it seems best to treat it as a subspecies. 
It inhabits lower and doubtless warmer localities than >n<</<d<>ps. in 
this respect, as well as others, standing between the megalops series 
and the mexicanus series. Its uniformly dark tail is almost diagnos- 


tic but not quite so. as rare variants in the mce'tcamis scries approach 
it. It is not so heavily haired as in melanocarpus. 

Specimens examined. — Total number 18, all from the type locality. 


Peromyscus melanocarpus Osgood, Proc. Biol. Soc. Wash., XVII, pp. 73-74, 
Mar. 21, 1904. 

Type locality. — Mount Zempoaltepec, Oaxaca, Mexico. 

Geographic distribution. — Known only from the upper slopes of 
Mount Zempoaltepec. 

Characters. — Similar to P. megalops, but smaller and darker; hind 
feet slightly darker; fore feet decidedly more so, the blackish extend- 
ing to base of digits; tail usually dusky all around and with only 
traces of paleness beneath ; pelage long and soft. 

Color. — No. 68627, adult $ , July 17: General effect of upper- 
parts dark blackish mummy brown, slightly darker along middle of 
back: actual color of subterminal zone of hairs cinnamon rufous, 
which is almost lost in the general effect by the many black-tipped 
hairs and the dark plumbeous undercolor which shows through the 
thin subterminal zone; underparts deep blackish slate washed w T ith 
creamy white, producing an effect which varies from olive gray to 
slate gray ; pectoral region usually rich cinnamon rufous ; an intense 
black line extending from nostrils through base of whiskers and eye: 
tail covered with short, bristly, blackish hairs scarcely paler below 
than above; scaly annulations of tail usually dusky all around, some- 
times with slight irregular patches of paler; fore and hind feet 
dusky brownish to base of toes. 

Skull. — Similar to that of megalops, but smaller; nasals slightly 
shorter and more compressed posteriorly. Superficially similar to 
that of totontepecus, but differing as follows: Nasals shorter and 
nearly always ending in advance of the orbits about on a plane with 
the infraorbital foramen; frontals wider and with decidedly greater 
development of supraorbital shelves; braincase wider; anterior pala- 
tine foramina much longer; molar teeth larger. Differs from that 
of lepturus, as follows: Braincase larger and broader; frontal wider 
and quite distinctly beaded; nasals longer. 

Measurements. — Type (not quite adult): Total length. '241; tail 
vertebrae, 125; hind foot, 27; ear from notch (dry), 19.2. Adult $ 
from Totontepec, Oaxaca : 262 ; 132 ; 30. 

Type specimen. — No. 68610 U. S. National Museum, Biological 
Survey Collection. 9 adolescent. July 8, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — This mountain species is about the size of P. m. totoii- 
tepecus, with which it ranges to some extent, but is much more closely 
related to megalops and auritus, as indicated by its cranial charac- 


ters and its more bristly tail. Its most diagnostic character, how- 
ever, is the extent of dusky brownish on the fore feet, which is almost 
unique. In some specimens the ends of the toes and the outer side 
of the metacarpus are the only parts not occupied by the dark color. 
The pelage is long and lax. like that of many other mountain forms. 
The type was taken at 8.000 feet altitude, and specimens from Toton- 
tepec on the north slope of the same mountain at 0.500 feet altitude 
show that it ranges to slightly lower levels. P. lepturus, which also 
occurs on Mount Zempoaltepec, is smaller than melanocarpus and 
differs in numerous cranial characters. 

Specimens examined. — Total number 0, from localities as follows: 
Oaxaca: Mount Zempoaltepec at 8,000 feet altitude, 1; Totontepec, 5. 


(PI. VI, fig. 1.) 

Peromyscu8 zarhynchus Merriam, Proc. Biol. Soc. Wash.. XII, p. 117, Apr. 30, 

Peromyscus zarhynchus cristobalensis Merriam, supra cit., pp. 117-118. — San 

Cristobal, Chiapas. 

Type locality. — Tumbala, Chiapas, Mexico. Altitude 5,500 feet. 

Geographic distribution. — Highlands of Chiapas and Guatemala. 

Characters. — Size very large, exceeded only in the subgenus Mega- 
dontomys • tail very long, always longer than head and body, rather 
finely scaly and scantily clothed with short hairs; soles of hind feet 
naked medially to calcaneum; color dark; skull with very elongate 

Color. — Unworn pelage? (No. 76120): Middle of back from 
shoulders to base of tail deep blackish brown very lightly sprinkled 
with russet, producing a general effect of mummy brown; sides, 
shoulders, and most of head cinnamon rufous mixed with dusky, pro- 
ducing a general effect varying from russet to Mars brown : lateral 
line rather broad, clear cinnamon rufous; orbital and antorbital 
regions dark blackish brown not very sharply contrasted; under- 
pays yellowish white, with or without pectoral spot, sometimes 
entirely suffused with cinnamon; feet soiled whitish, tarsal joint 
broadly brownish and proximal part of foot slightly brownish; scaly 
part of tail evenly bicolor, dusky above and whitish below or dusky 
above and irregularly blotched below. Worn pelage: Slightly paler, 
more grayish, than in unworn pelage and with dark dorsal area less 

Skull. — Size very large, equaling that of P. thomasi in length but 
general form lighter; nasals, rostrum, palatine slits, etc.. very long; 
shelf of bony palate rather short ; interpterygoid fossa and audital 
bullae about as in guatemalensis and thomasi; frontals quite con- 
stricted; supraorbital border sharp-angled but rarely showing any 


definite bead; zygomata slightly compressed anteriorly and but 
slightly notched; lower side of infraorbital plate somewhat pro- 
duced forward; teeth larger than in guatemalensis but smaller than 
in thomasi. 

Measurements. — Average of 10 adult topotypes: Total length 316 
(305-327) ; tail vertebrae 170.7 (162-178) ; hind foot 35.7 (33.5-38) ; 
ear from notch (dry) 22.2 (21.2-24). Average of 10 adults from 
San Cristobal, Chiapas: Total length 312 (303-323); tail vertebrae 
166 (157-174) ; hind foot 33.8 (33-36). 

Type specimen. — No. 76119 U. S. National Museum, Biological 
Survey Collection. 9 adult, October 20, 1895. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — This is the largest species of Peromyscus except those 
of the subgenus Megadontomys. Its size, therefore, is sufficient to dis- 
tinguish it. The skull is characterized by a very long rostrum, 
longer even than in Megadontomys. The supraorbital border is not 
beaded, being about as in guatemalensis. The teeth are not peculiar, 
but a few specimens show a faint suggestion of the inner enamel 
island of the anterior triangle of the first upper molar, which is well 
developed in Megadontomys. This species is represented by two 
fairly good series, one from Tumbala and one from San Cristobal. 
There is considerable variation in each series, both in color and in 
cranial characters. No constant, nor even average, difference in 
cranial characters appears, and in color the very slight average dif- 
ference is scarcely more than is found between any two series of one 
species. The environmental conditions of Tumbala and p San Cristo- 
bal are nearly alike, and the distance between the two places is not 

Specimens examined. — Total number 36, from localities as follows : 

Chiapas: San Cristobal, 22; Tumbala, 14. 

Subgenus MEGADONTOMYS Merriam. 

Megadontomys Merriam, Proc. Biol. Soc. Wash., XII, pp. 115-116, Apr. 30, 1S98. 

Type. — Peromyscus thomasi Merriam. 

Snbgeneric characters. — Size very large, slightly exceeding the 
largest species, and greatly exceeding the majority of the species of 
the other subgenera of Peromyscus; molar teeth largest and heaviest 
of the genus; tubercles of molars low and usually worn flat at an 
early stage; supplementary tubercles (in primary angles of both 
upper and lower molars) more highly developed than in the subgenus 
Peromyscus ; first upper molar, when slightly worn, presenting five 
salient and four reentrant outer angles; anterior loop of first upper 
molar, wdien somewhat more worn, containing a subcircular enamel 
island, which is the persistent part of the first outer reentrant angle ; 
first and second lower molars with a prominent and well-developed 


supplementary enamel loop in the outer primary reentrant angles; 
third lower molar presenting three salient and three reentrant angles 
on each side during a much longer period of wear than in the sub- 
genus Peromyscus. Plantar tubercles of hind foot 6, as in Peromyscus. 
Mammae 6, pectoral j, inguinal §. 

Species. — P. thomasi, P. nelsoni, and P. flavidus. 

Remarks. — Nearly all the characters of this subgenus are relative 
rather than absolute. The development of the supplementary cusps, 
particularly those of the lower molars, gives the enamel pattern of 
the worn tooth quite a different appearance from that in the sub- 
genus Peromyscus. These supplementary cusps, however, are quite 
well developed in the upper molars of true Peromyscus, and are 
present also, but little developed, in the lower molars. As seen in 
the profiles of unworn teeth, these cusps are merely larger and higher 
in Megadontomys than in Peromyscus. Therefore the slightly worn 
surface of the molars of Megadontomys presents a pattern different 
from that of Peromyscus at the same stage of wear, but when the 
molars of Peromyscus are worn to a greater degree the cross section 
shown by the upper surfaces is essentially the same as that of 
Megadontomys. In Ilaplomylomys, the ' supplementary cusps ' are 
entirely absent, in Peromyscus they are variously developed, and in 
Megadontomys ,they find their greatest development. Some authors 
have hastened to give Megadontomys full generic rank, but in view 
of the relative nature of its characters this seems ill advised. 

Key to species of subgenus Megadontomys. 

Anterior tubercle of first upper molar distinctly divided longitudinally P. flavidus 

Anterior tubercle of first upper molar scarcely or not at all divided. 

Supraorbital border somewhat beaded- P. thomasi 

Supraorbital border not beaded P. nelsoni 


(PI. V, fig. 13; pi. VI, figs. 3-3a; pi. VII, fig. 5; pi. VIII. figs. 1, la, lb, lc.) 
Peromyscus (Megadontomys) thomasi Merriam, Proc. Biol. Soc. Wasb., XII, 

pp. 11G, 120, fig. 20, Apr. 30, 189S. 
Megadontomi/s thomasi Bangs, Bull. Mus. Comp. Zool., XXXIX. p. 27, 1902. 

Type locality. — Mountains near Chilpancingo, Guerrero, Mexico. 
Altitude, 9,500 feet. 

GeograpJtic distribution. — High altitudes in mountains of central 
Guerrero, Mexico. 

Characters. — Size very large, equaling and often slightly exceed- 
ing P. zarhynchus; tail decidedly longer than head and body, nearly 
unicolor and closely covered with short bristly hairs, which do not 
quite conceal the annulations; ears large and minutely hairy, ap- 
pearing almost naked ; soles of hind feet naked to calcaneum : pelage 
long and rather coarse; color similar in general to that of P. mega- 
lops; skull with supraorbital beads. 


Color. — Unworn pelage: General color much as in P. megalops, 
but averaging slightly darker. Upperparts rich tawny mixed with 
black, the tawny everywhere predominating; back only very slightly 
darker than sides; sides with relatively little black admixture, leav- 
ing the general effect from the cheeks to the thighs nearly pure 
tawny; nose and region about base of whiskers black; orbital ring 
black: underparts creamy white, usually somewhat modified by slaty 
under color, and occasionally with a slight suffusion of tawny in the 
pectoral region ; fore feet white ; forearm dusky brownish three- 
fourths of the way around: hind feet white, tarsal joint and distal 
part of hind leg dusky brownish all around; hairs of tail dusky all 
around; scaly part of tail chiefly dusky above and below, but occa- 
sionally light yellowish on proximal half of under side. Worn 
pelage: Similar to unworn pelage, but general appearance rougher; 
under color more or less exposed and an extensively dusky dorsal area, 
well differentiated. 

/Skull. — Size very large, equaling that of zarhynchus in length and 
exceeding it in massiveness; supraorbital border distinctly beaded; 
nasals long, slightly shorter and wider than in zarhynchus; zygomata 
decidedly convergent anteriorly and scarcely notched by infraorbital 
foramen ; interparietal very large, often produced to a sharp angle 
posteriorly; palatine slits very large; interpterygoid fossa wide; 
audita! bulla 1 moderate, about as in zarhynchus; molar teeth large 
and heavy, larger than in any species of the subgenus Peromyscus; 
molar enamel pattern peculiar in most stages of wear (see subgeneric 

Measurements. — Average of 7 adult topotypes: Total length, 330 
(310-350) ; tail vertebra?, 175 (162-188) ; hind foot, 32.8 (32-34) ; 
ear from notch (dry), 23 (21.4-24.8). 

Type specimen. — No. 70142 U. S. National Museum, Biological 
Survey Collection. $ adult. Dec. 24, 1894. E. W. Nelson and 
E. A. Goldman. Specimen in good condition. 

Remarks. — Although equaled, or nearly equaled, in size by P. za- 
rhynchus, this species is so well characterized by cranial and dental 
characters as not to require close comparison. Its only close relation- 
ship, of course, is with the other member of the subgenus Mega- 
dontomys (nelsoni), from which is is distinguished by its lighter, 
more extensively tawny color and bj 1, its distinctly beaded skull. Ex- 
ternally it very closely resembles P. megalops, merely being somewhat 
larger and showing the same character of pelage and the same 
extensively tawny color in unworn pelage. 

Specimens examined. — Total number 14, from localities as fol- 
lows : 

Guerrero: Mountains near Chilpancingo, 7; Omilteme, 7. 



Peromyscus {Megadontomys) nels.oni Merriam, Proc. Biol. Soc. Wash., XII, pp. 

116-117, Apr. 30, 1898. 
Megadontomys nelsoni Bangs, Bull. Mus. ('(imp. Zool., XXXIX, p. 27, 1902. 

Type locality. — Jico, Veracruz, Mexico. Altitude 0.000 feet. 

Geographic distribution. — Known only from the type locality. 

Characters. — Similar to P. thomasi but color less extensively tawny 
and skull without distinct supraorbital beads. 

Color. — Slightly worn pelage: Upperparts mixed tawny and 
dusky ; general effect of sides cinnamon to russet and tawny olive ; 
middle of back with dusky largely predominating, general effect 
raw umber to bister; dusky markings about eyes and base of whiskers 
rather heavy ; fore feet white ; forearm dusky to wrist ; hind feet 
grayish dusky; toes white, tarsal joint broadly brownish; tail uni- 
color, dusky all around. 

Skull. — Similar to that of thomasi, but frontals slightly more con- 
stricted and supraorbital beads comparatively undeveloped. 

Measurements. — Type and one topotype, respectively : Total length, 
302, 318; tail vertebras, 172, 170; hind foot, 35, 32; ear from notch 
(dry), 20. 

Type specimen. — No. 55024 U. S. National Museum, Biological 
Survey Collection. 9 adult. July 10, 1893. E. W. Nelsonand 
E. A. Goldman. Specimen in good condition ; last left upper molar 

Remarks. — Probably the real color difference between nelsoni and 
thomasi is rather slight or practically nothing. The only known 
specimens of nelsoni are in slightly worn pelage and, although differ- 
ent from the majority of specimens of thomasi, are scarcely distin- 
guishable from equally worn specimens. The absence of supraorbital 
beads, however, appears to be distinctive. 

Specimens examined. — Total number 2, both from the type locality. 


(PI. VI, figs. 2-2a; pi. VII, fig. S.) 

Megadontomys flavidus Bangs. Bull. Mus. Comp. Zool., Cambridge, .Mass., 
XXX1X. pp. 27-29, figs. 5-7, Apr.. 1902. 

Type locality. — Boquete, south slope Volcan de Chiriqui, Panama. 

Geographic distribution. — Known only from the type locality. 

Characters. — Similar to P. thomasi but decidedly larger; ears rela- 
tively smaller; color slightly paler with less dusky about head; skull 
with heavy rostrum characterized by long nasals and laterally swollen 
premaxillge; anterior lamina of first upper molar longitudinally 

Color. — Similar to that of thomasi, but averaging slightly paler; 
blackish markings about head less extensive, chiefly confined to base 


of whiskers; underparts more yellowish; entire upperparts, head, 
back, sides, etc., rich ochraceous rather coarsely lined with dusky; 
lower cheeks and lateral line ochraceous scarcely or not at all mixed 
with dusky; nose and forehead a slightly paler shade of ochraceous 
than body; a narrow dusky orbital ring and a well-defined brownish 
dusky spot at base of whiskers; underparts yellowish white, without 
pectoral spot; forearm dusky to wrist; fore feet white; hind feet 
whitish, more or less mixed with dusky brownish to base of toes; 
toes white; tail thinly clothed with very short hairs, usually indis- 
tinctly bicolor. Worn pelage: Upperparts a richer shade of ochra- 
ceous (more nearly tawny), with dusky mixture slightly modified 
and blended. 

Skull. — Decidedly different from that of P. thomasi; larger, higher, 
and relatively narrower; rostrum much heavier, with nasals more 
extended backward and premaxillse much more swollen laterally; 
anterior palatine foramina shorter and wider; teeth and audital bullae 
actually and relatively smaller; supraorbital beads strongly de- 
veloped; nasals ending far back, at least on plane of lacrymals; inter- 
parietal scarcely produced posteriorly; coronoid process of mandible 
broad, strong, and elevated; teeth relatively short and broad; ml 
with anterior lamina distinctly divided, making 6 cusps instead of 5; 
lower molars with supplementary loops slightly developed, much 
less than in Megadontomys, about as in Peromyscus. 

Measurements. — Average of 10 adult topotypes: Total length, 341.6 
(320-375) ; tail vertebras, 181.2 (155-205) ; hind foot, 31.8 (31-33) ; 
ears, 22.5 (20-24). 

Type specimen. — No. 10331 Museum Comparative Zoology. Cam- 
bridge, Mass., formerly same number, collection of E. A. and O. 
Bangs. S adult. April 12, 1901. W. W. Brown, jr. 

Remarks. — The inclusion of this species within the genus Pero- 
myscus is provisional. In dentition it decidedly approaches several 
neotropical genera. The first upper molar in fact is almost com- 
pletely six-cusped, whereas in typical Peromyscus this tooth is five- 
cusped. However, an approach to the six-cusped condition is shown 
in P. thomasi, in which the anterior lamina of the tooth is incom- 
pletely divided. Moreover, P. thomasi is closely similar to P. flavi- 
dus in external characters. Since the generic relationships of various 
neotropical murines are imperfectly understood, it seems best for the 
present to retain P. flavidus in the subgenus Megadontomys. 

/Specimens examined. — Total number 27, all from the type locality. 

Subgenus OCHROTOMYS nobis. 

Type — Arvicola nuttalli Harlan (=Peromyscus'' nitttalli). 
Subgeneric characters. — Color of young in first pelage essentially 
same as that of adult; hairs clothing ears of same color as those of 


upperparts; abdomen suffused with color of upperparts. Plantar 
tubercles 6, with a rudimentary seventh, adjacent to the large tuber- 
cle at the base of the fifth digit. Mammae 6; inguinal f, pectoral^. 
Posterior palatine foramina situated farther back than in Pero- 
myscus, being decidedly nearer to the interpterygoid fossa than 
to the posterior endings of the anterior palatine slits. Molariform 
teeth relatively wide, and with enamel folds much compressed ; tuber- 
cles relatively low ; a tendency to development of a raised cingulum 
marked by subsidiary tubercles in the inner salient angles of ml and 
m2 ; enamel relatively thicker than in subgenus Peromyscus, the pat- 
tern as seen in partly worn teeth being much compressed both lat- 
erally and longitudinally, so that the folds of the two sides touch in 
almost all stages of wear, leaving five subtriangular islands of dentine 
in ml and four in m2 ; lower molars similarly peculiar. 

Species. — One, the type only. 

Remarks. — It is rather surprising that the numerous characters 
of P. nuttalli have not been accorded more than specific rank. It 
differs widely from all other species of the genus in external, cranial, 
and dental characters. Its general appearance is striking, not only 
on account of the bright uniform color, the ochraceous ears and belly, 
but also for the peculiar pelage, which is extremely dense and soft, 
suggesting that of the tropical murine opossums. 

Although the tubercles of its teeth number the same as in the sub- 
genus Peromyscus, and, as seen in cross section, show the same num- 
ber of enamel folds, the relation of these folds to each other and to 
the dentine is different. In general, the enamel is thicker and occu- 
pies a relatively greater part of the upper surface of the worn tooth. 
Except in extremely old individuals, the dentine areas are not con- 
fluent, whereas in Peromyscus, even in teeth but slightly worn, these 
areas are all, or nearly all, confluent through narrow constrictions. 
This gives the worn surface of the tooth a characteristic aspect 
which, upon hasty examination, might lead to the conclusion that the 
enamel pattern is much more complicated than in true Peromyscus. 
The tendency to greater development of a raised cingulum is difficult 
to appreciate without examination of many teeth of different ages. 
"When the teeth are worn to the level of this raised part of the cingu- 
lum (and this occurs before the obliteration of any important 
angles), the lateral angles are bridged, as it were, and the outer 
boundaries of the teeth are entire ; that is, all the angles are inclosed. 

Key to subspecies of Peromyscus nuttalli. 

Size larger; maxillary toothrow about 4 P nuttalli 

Size smaller; maxillary toothrow usually less than 4 , P. n. aureolus 



[no. 28. 

PEROMYSCUS NUTTALLI (Harlan). Northern (Jolden Mouse. 
(PI. V, fig. 11; pi. VI, figs. 7-7a; pi. VII, fig. 2; pi. VIII, figs. 5-5a.) 

Arvicola nuttalli Harlan, Monthly Am. Jour, of Geol. and Nat. Sci., Phila., I, 

pp. 446-447, Apr., 1832; Med. and Phys. Researches or Orig. Memoirs, Phila., 

pp. 55-56, col. i>l., L835. 
Hesperomys nuttalli P.aird, Mamm. N. Am., Pac. R. R, Rei)ts., VIII, pp. 467^68, 

Peromyscus nuttalli Bangs, Proc. Post. Soc. Nat. Hist., XXVIII, p. 197, Mar., 


Type locality. — Norfolk, Va. 

Geographic distribution. — Southeastern Virginia and northern 
North Carolina ; west to central Kentucky. 

Characters. — In general those of the subgenus Ochrotomys, of 

which it is the only 

Peromyscus nutfolli 
R n. aureotus. 

species. Pelage very 
soft and thick ; color 
chiefly rich tawny 
ochraceous ; ears 
same color as body; 
abdomen suffused 
w it h ochraceous; 
proximal half of 
hind foot hairy ; 
skull and teeth some- 
what peculiar. 

Color. — Upper- 
parts in all pelages 
rich tawny ochra- 
ceous, nearly clear on 
sides, lightly mixed 
with dusky on back 
in fresh pelage ; face 
and head exactly like sides; underparts creamy white suffused with 
ochraceous on abdomen, this often extending to entire underparts 
except chin and throat; hairs with slate-colored bases throughout, 
except on chin and throat and a small inguinal area where they 
are creamy white to the roots; ears tawny ochraceous like sides; 
whiskers mixed brownish and whitish, no dusky spot at base and no 
orbital ring; forearm extensively ochraceous; feet creamy white; tail 
pale brownish (near broccoli brown) above, creamy white below. 
Young : Similar to adults but slightly paler ; ears thickly haired and 
conspicuously bright ochraceous. 

Skull. — Somewhat similar in general form to that of leucopus but 
relatively broader; braincase rather full, somewhat elevated; nasals 
rather short, usually somewhat compressed posteriorly; rostrum 

Fig. 9.- 

-Dlstribution of PerGmyscus nuttalli and P. n. 


rather broad, particularly across lacrymals; interpterygoid fossa 
broad and nearly square-angled anteriorly; posterior palatine 
foramina about opposite middle of m2, decidedly nearer to inter- 
pterygoid fossa than to plane of front of ml; molar teeth peculiar 
(see subgeneric diagnosis). 

Measurements. — Average of 10 adults from the Dismal Swamp, 
Virginia: Total length, 181 (170-190); tail vertebrae, 85 (80-93); 
hind foot, 19.7 (19-20) ; ear from notch (dry), 15.5 (14.4-16.4). 

Type specimen. — Not known to be in existence. 

Remarks. — The many characters of this species make it unmis- 
takable. To those unfamiliar with it the color of the ears alone will 
serve as a means of certain identification, for it is the only species in 
the genus having ochraceous ears, the same color as the body. It is 
perhaps best known under the name aureolus, which has long been in 
use. The name nuttalli, employed by Baird in 1857 and then dis- 
carded by later authors, was revived by Bangs in 1898. The original 
description by Harlan does not mention any characters that are 
diagnostic; indeed it states that the animal was " fawn-coloured above, 
whitish beneath,'' which really applies better to leueopus than to this 
species. However, a colored figure published two years later by the 
same author more nearly represents this species than leueopus or 
gossypinus, the only others which might have been found at Norfolk, 
the type locality. It represents a mouse with ears colored like the 
body and with the underparts washed with buffy. It shows also the 
body color extending entirely over the feet, a peculiarity not found 
in any of the species and which might be taken to discredit the figure 
altogether. Since, however, nothing definite can be proved it seems 
best to follow current usage and allow the name nuttalli to stand for 
the species under consideration. Specimens from the Dismal Swamp, 
Virginia, only a few miles from Norfolk, are larger and have larger 
molar teeth than specimens from more southern localities and seem 
subspecifically separable. The name nuttalli therefore will stand for 
this northern form, and for the southern and more widely ranging 
form the well-known name aureolus is available. 

Specimens examined. — Total number 90, from localities as follows : 

Kentucky: Eubauks, 7. 

North Carolina: Asheville, 1; Buncombe, 3: Highlands, 1; Magnetic 

City, foot of Roan Mountain, 7: Weaverville, 29. 
Tennessee: High Cliff, 1; Knoxville, 1. 
Virginia: Dismal Swamp, 40. 

PEROMYSCUS NUTTALLI AUREOLUS (Aud. and Bach.). Southern Golden 


Mm (Calomys) aureolus Audubon and Bachman, Proc. Acad. Nat. Sci., I, 

pp. 98-99, 1841. 
Peromyscus aureolus Trouessart, Catal. Mamm., p. 517, 1897, 

66268— No. 28—09 15 


Type locality.— ■" In the oak forests of South Carolina." 

Geographic distribution. — Southeastern United States from North 
Carolina to northern Florida; west to eastern Texas and Oklahoma. 
Lower Austral zone. 

Characters. — Similar to nuttalli, but averaging smaller; skull and 
molar teeth smaller. 

Color. — As in nuttalli ; at the extreme of its range possibly averag- 
ing very slightly paler. 

Skull. — Similar to that of nuttalli, but smaller and narrower ac- 
tually and relatively; molar teeth quite decidedly smaller. 

Measurements. — Average of 7 adults from Milton, Fla. : Total 
length, 172.5 (164-184); tail vertebras, 83 (80-88); hind foot, 18.8 
(17-20) ; ear from notch (dry), 14.1 (13.4-14.6). Of a large male 
from Augusta, Ga.: Total length 175; tail vertebras 90; hind foot 19; 
ear from crown 11.5; ear from notch 17. 

Type specimen. — Not known to be extant. 

Remarks. — The amount of difference between this form and typical 
nuttalli is not great, but is reasonably constant in the material thus 
far examined. Two small series from Eubanks, Ky., and Magnetic 
City, N. C, respectively, have been referred to nuttalli on account 
of their rather large teeth. Their skulls, however, are not very large, 
and it is not improbable that larger series from these localities would 
prove to be more or less intermediate. A large series from Raleigh, 
N. C, seems referable to aureolus, though somewhat intermediate. 

Specimens examined. — Total number 160, from localities as follows : 

Alabama: Brewton, 1 ; Huntsville, 1 : Mobile Bay, 1. 

Arkansas: Beebe, 1. 

Florida: Enterprise, 2 : Gainesville, 2; Jacksonville, 1; Milton, 8; New 

Berlin, 1; San Mateo ( 10 m. southeast), 1; Tallahassee, 3; Whit- 
field, 6.° 
Georgia: Augusta, 8; Hoschton, 1: Pinetucky, <>; Kieeboro? ("Southern 

States,"' Leconte), 1. 
Louisiana: Mansfield, 1. 
Missouri: St. Louis, 1. 
North Carolina: Apex, 2: Bertie County. 2: Chapanoke, 4; Raleigh, 02; 

Roanoke Rapids, 1. 
Oklahoma: Redland, 2. 

South Carolina: Calhoun Falls, 8; Charleston, 1; Columbia, 1. 
Texas: Joaquin, 1. 

Subgenus PODOMYS nobis. 

Type. — Hesperomys foridanus Chapman (=Peromyscus flori- 

Subgeneric characters. — Plantar tubercles of hind foot 5 instead 
of 6, as in the other subgenera of Peroniyscus; digital tubercles 3, 
phalangeal 2, the latter much reduced in size and subcircular in shape. 

a Carnegie Museum. 

1909.] , SUBGENUS PODOMYS. 227 

Molar teeth slightly more hypsodont than in Peromyscus, less so than 
in Onychomys; accessory tubercles in salient inter angles of molars 
very small, as seen in transverse section, never forming a, loop which 
extends to the outer edge of the tooth, as in Peromyscus. Mammae : 
6 (L, |, a., £, p., \). 

Species. — One, the type only. 

Remarks. — The constancy of the number and relative size of the 
plantar tubercles throughout the genus Peromyscus is so great that 
the decided departure shown by /'. fioridanus must be considered of 
more than specific importance. In other respects the species does not 
differ so greatly from Peromyscus, although its skull is well charac- 
terized specifically, and its teeth are somewhat peculiar. The reduc- 
tion in the number of plantar tubercles and the large, slightly more 
hypsodont teeth suggest the possibility that this form may be inter- 
mediate between Peromyscus and Onychomys. 

Fresh or alcoholic specimens are necessary for an appreciation of 
the character of the plantar tubercles, as in dry specimens the 
tubercles are so much distorted that their character, or even their 
number*, may be mistaken. 

(PI. V. fig. 14; pi. VI, figs. 6-6a; pi. VII, fig. 1; pi. VIII, fig. 8.) 

Hesperomys floridanus Chapman, Bull. Am. Mus. Nat. Hist., N. Y., II, p. 117, 

June, 1889. 
Hesperomys macropus Merriam, N. Am. Faima No. 4, pp. 53-54, Oct. 8, 1890. 

Lake Worth, Florida. 
Peromyscus floridanus Bangs, Proc. Biol. Soc. Wash., X, p. 122, 189G. 

Type locality. — Gainesville. Fla. 

Geographic distribution. — The central part of peninsular Florida 
from coast to coast. 

Characters. — Size large (hind foot 25-27) ; tail shorter than head 
and body; ears large and thinly haired; proximal fifth of sole of 
hind foot hairy, remainder nearly naked; plantar tubercles 5 (see 
siibgeneric diagnosis) ; color paler than in leucopus or gossypinus. 

Color. — Unworn pelage: Top of head, neck, back, and upper sides 
pale ochraceous buff finely mixed with dusky, producing a pale 
grayish-cinnamon effect ; lower sides from nose to base of tail rich 
ochraceous buff, very lightly or not at all mixed with dusky; sub- 
auricular tufts mixed pale ochraceous buff and dusky; thin hairiness 
of outside of ears dusky, of inside whitish; underparts creamy white, 
often with an ochraceous buff pectoral spot ; feet and forelegs chiefly 
white, upper side of hind feet somewhat dusky at base ; tail brownish 
dusky above, creamy white below. Worn pelage: Similar to unworn 
pelage, but sides more broadly ochraceous and back less dusky: tail 
often ding}' and very indistinctly bicolor. Adolescent pelage: 


Scarcely different from adult pelage, possibly a little more dusky 
with sides less broadly ochraceous. Young in first coat : General 
effect of upperparts varying from smoke gray to drab gray, shading 
into mouse gray on middle of back. 

Skull. — Size large and depth relatively great; supraorbital border 
rather sharp and shelf like ; posterior end of nasals slightly exceeding 
ascending branches of premaxillaries ; palatine slits rather short and 
expanded; interpterygoid fossa rather wide and nearly right-angled 
anteriorly. Molars large and broad, the tubercles considerably ele- 
vated; accessory tubercles between outer salient angles small or 
scarcely evident. 

Measurements. — Average of 10 adults from Fort Gardner, Fla. : 
Total length, 199.8 (190-221) ; tail vertebra?, 86.2 (80-95) ; hind foot, 
26.6 (26-27.5) ; ear from notch, 22.5 (22-25). 

Type specimen. — No. 1812 American Museum of Natural History, 
New York. Skin without skull. Immature. Sex (?). Oct., 1888. 
J. H. P. Bell. Skin in rather poor condition, both hind legs dang- 
ling, distal half of tail gone. 

Remarks. — P. floridanus is the largest species of Peromyscus native 
in the eastern United States. This fact alone serves to distinguish 
it without reference to its subgeneric characters. The limited dis- 
tribution of this very distinct form suggests that it may be one of the 
well-known stranded forms representing a group of former wide dis- 
tribution. Of its habits in Florida, Bangs says: a 

It lives only in the higher sandy ridges, where there is plenty of black-jack 
oak and turkey oak, and where the bare white sand is in places covered by scat- 
tered patches of scrub palmetto. It is the characteristic small mammal of 
such places, commonly known as ' black-jack ridges,' and I have never found 
it elsewhere. 

Specimens examined. — Total number 147, from localities as follows : 

Florida: Anastasia Island, S; Blitch Ferry, 1; Canaveral, 2; Citronelle, 
4; Crystal River, 1; Eau Gallie, 5; Enterprise, 69; Fort Gardner, 
Kissimee River, 29; Gainesville. 2; Lake Worth, 8; Micco, 9; 
Miami, 3; Ocklawaha River, 2: Sebastian, 1; Tarpon Springs, 3. 

Subgenus HAPLOMYLOMYS Osgood. 

Haplomylomys Osgood, Proc. Biol. Soc. Wash., XVII, pp. 53-54, fig. 1, Mar. 
21, 1904. 

Type. — Hesperomys eremicus Baird ( = P<ro///yscus eremicus). 

Characters. — Tail rather long, always longer than head and body; 
plantar tubercles 6; mammae 4 (i., f, a., -§-, p., £ ) ; skull with 
cranium rather large and rostral region relatively weak; first and sec- 
ond upper molars usually with three salient and two reentrant outer 
angles at all stages of wear; accessory tubercles between outer pri- 

°Proc. Bost. Soc. Nat. Hist., XXVIII, p. 194, Mar., 1898, 


mary tubercles very rudimentary or absent; lower molars corre- 
spondingly simple. (See PL VIII, figs. 3— i). 

Species. — P. eremicus, P. californicus, P. goldmani, and P. 

Remarks. — The simple character of the molar teeth is usually 
diagnostic of this group. No accessory cusps are evident either in 
transverse or longitudinal views of the molars, except in P. erinitus, 
and in this species they are extremely reduced. The presence of 
these accessory cusps in the other subgenera is, however, not always 
obvious at all stages of wear. Therefore it often requires close 
examination to determine properly the position of individual speci- 
mens. The external appearance of the members of this subgenus is 
slightly peculiar but not readily described, although experienced 
workers find little difficulty in its recognition. P. calif ornicus and 
P. eremicus are usually recognized by their naked or nearly naked 
soles, but this peculiarity does not extend to P. erinitus and P. 
goldmani. P. erinitus is the most aberrant member in this group 
on account of the approach to the subgenus Peromyscus indicated by 
its molar teeth, but since it has only two pairs of mammas it seems 
best to include it here. 

Key to species of the subgenus Haplomylomys. 

Size large; hind foot 25-29 P. californicus 

Size smaller ; hind foot 19—24. 
Hind foot 19-22. 

Zygomata compressed anteriorly ; nasals attenuate, slightly or not at all exceeded 

by premaxilla? P- erinitus 

Zygomata less compressed anteriorly ; nasals broader and flatter ; decidedly ex- 
ceeded by premaxillae P. eremicus 

Hind foot 22-24; sides of head ochraceous P. goldmani 

Key to subspecies of Peromyscus erinitus. 

Size smaller; hird foot 19-20; greatest length of skull usually less than 24; color pale 

Southern Nevada to northern Lower California P. c. stepliensi 

Size larger ; hind foot 20-21 ; greatest length of skull usually more than 24 ; color not 
so pale. Great Basin region from Oregon and Idaho to Arizona and New Mexico. 
Color more buffy ochraceous with a minimum of dusky mixture— P. c. auripectus 
Color more grayish with a larger mixture of dusky P. erinitus 

PEROMYSCUS CRINITUS (Merriam). Canyon Mouse. 

(PI. Ill, fig. 9.) 

Hesperomys erinitus Merriam, N. Am. Fauna, No. 5, pp. 53-54, July 30, 1891. 
Peromyscus truei erinitus Trouessart, Catal. Mamm. Viv. et Foss., p. 517, 1897. 
Peromyscus erinitus scitulns Bangs, Proc. New Eng. Zool. Club, I, p. 67, July 

31, 1899.— Gardnerville, Nev. 
Peromyscus erinitus Bangs, supra tit. 

Type locality. — Shoshone Falls, Snake River, Idaho. 

Geographic distribution. — Rocky cliffs and canyons of southern 
Idaho, eastern Oregon, eastern California, northern Nevada, and 
northwestern Utah. Upper Sonoran zone. 



[no. 28. 

l*» o 

/ * y o* 

Characters. — Size medium; tail longer than head and body, thickly 
covered with long, soft hairs, terminating in a distinct pencil; ears 
rather large; pelage usually long and lax; hind foot hairy on proxi- 
mal fourth or naked in median part to calcaneum; skull with rather 
wide, shallow braincase, and long, slender nasals. 

Color. — Adult in new fall pelage: Upperparts pale ochraceous buff 
uniformly mixed with dusky; forehead, nose, and upper face slightly 
grayish; underparts white, frequently with a faint pectoral spot of 
buff; tail bicolor, sooty blackish above, white below; hands and feet 
white. Immature: Less buffy than adult, general color more grayish. 
Skull. — Braincase broad and somewhat flattened; zygomata com- 
pressed anteriorly; rostrum slightly depressed and more or less 

rounded dorsally ; nasals 
long and somewhat com- 
pressed posteriorly ; ascend- 
ing branches of premaxillse 
usually attenuate and rare- 
ly exceeding nasals; audi- 
tal bulla? moderate; molar 
teeth with accessory tuber- 
cles between outer angles 
very small and inconspicu- 
ous, worn teeth often show- 
ing same simple enamel 
pattern as in P. eremicus. 

Measurements. — Average 
of 9 topotypes: Total 
length, 176 (172-184) ; tail 
vertebras, 95 (92-97) ; hind 
foot, 21 ; ear from notch 
(dry), 10.3 (15.4-17.5). 

Type specimen. — No. 
fflfl U. S. National Mu- 
seum, Biological Survey Collection. $ adult. Oct. 10, 1890. C. Hart 
Merriam and Vernon Bailey. Specimen in good condition. 

Remarks. — P. crinitus is a very distinct species confined chiefly to 
the Great Basin region. It is apparently rare, for it has been ob- 
tained at only a small number of localities and in limited numbers. 
Externally it is characterized by soft silky pelage, much as in P. 
eremicus, and by a hairy crested tail. It appears to be more closely 
related to P. eremicus than to any other species and apparently con- 
nects Peromyscus proper and Haplomylomys. It is referred to 
Haplomylomys because it has four mamnue. as in the other species of 
Haplomylomys, instead of six as in the subgenus Peromyscus. Many 
specimens show the simple enamel pattern as in P. eremicus and P. 

* ft ,/T ' 

R crinitus 
£ c. Stephens/ 

Pc. aur /pectus { o 


Fig. 10. — Distribution of Peromyscus crinitus and 


californicus, but examination of large series of all ages proves the 
existence of the small tubercles as in typical Peromyscus, but so re- 
duced in size as to be almost obsolete. P. crinitus may be distin- 
guished from eremicus, regardless of other characters, by the rostral 
part of the skull. In crinitus the rostrum is more elongate, depressed, 
and rounded; the zygomata are much more compressed anteriorly; 
and the premaxilhe do not exceed the posterior ends of the nasals. 
The pelages of crinitus differ chiefly in the amount of dusky admix- 
ture present. The new fall pelage is strongly dusky and the general 
effect of the upperparts is decidedly grayish. In summer (June and 
July) specimens become worn, the dusky fades to brownish, and the 
buff or ochraceous buff ground color becomes dominant. Immature 
specimens are invariably grayish in general color. 

P. crinitus scitulus seems to be the same as crinitus, having been 
based on August specimens in which the pelage appears more fulvous 
than in the Shoshone Falls specimens taken in October. 

Specimens examined. — Total number 63, from localities as follows : 

California: Arnedee, 6; Coleville, 2: Susanville, 1. 

Idaho: Shoshone Falls, 12: Silver Creek, 1. 

Nevada: Anderson Ranch, Douglas County, 12; Elko, 1; Gardnerville, 9; 

Granite Creek, 3; Pyramid Lake, 4; Smoke Creek Desert. 1. 
Oregon: Crooked River (20 m. southeast Prineville), 2; Haruey, 4; 

Narrows, 1. 
Utah: Beaver River, near Fort Cameron, 3; Parawan, 1 (not typical). 



Sitomys atiripeetus Allen, Bull. Am. Mus. Nat. Hist., N. Y., V, pp. 7r>-7<*>, Apr. 

28, 1893. 
Peromyscus auripectus Allen, Bull. Am. Mus. Nat. Hist., N. Y., VII, pp. 

226-227, June 29, 1895. 

Type locality. — Bluff City, San Juan River, Utah. 

Geographic distribution. — Known from a limited number of locali- 
ties in northeastern Arizona, southeastern Utah, and adjacent parts 
of Colorado and New Mexico. 

Characters. — Similar in general to P. crinitus, but lighter colored 
and more buffy; tail heavily haired; skull as in crinitus. 

Color. — Full winter pelage : Upperparts rich ochraceous buff, 
faintly lined with dusky on back, nearly clear on sides; head and 
face ochraceous buff; ears dusky brownish edged with buffy white; 
lanuginous ear tufts buffy sometimes mixed with white; underparts 
creamy white, frequently with a buffy ochraceous pectoral spot : en- 
tire underparts occasionally suffused with buffy; tail dusky brownish 
above, white below ; hands and feet white. 

Skull. — As in P. crinitus; possibly averaging slightly larger. 


Measurements. — Average of 10 adult topotypes: Total length, 
177.7 (174-182) ; tail vertebrae, 93 (89-98) ; hind foot, 20.8 (20-21) ; 
ear from notch (dry), 17.3 (16.6-18). 

Type specimen. — No §|4t American Museum of Natural History, 
New York. ? adult. May 14, 1892. C. P. Rowley. Specimen in 
fair condition; skull with several slight imperfections. 

Remarks. — In full winter pelage, this is a very attractive species. 
Its rich buff color is nearly unmixed with dusky and it is therefore 
quite conspicuous. It is really very closely related to crinitus, the 
chief difference being in color. Specimens from the Grand Canyon, 
Arizona, distinctly tend toward P. c. stephensi. The pectoral spot 
is variable and not always present. It is rather frequent among 
specimens from the type locality, but occurs in very few of a series 
from Holbrook, Arizona, and is then imperfectly developed. The 
Holbrook specimens, however, have a decided buffy suffusion through- 
out the underparts. 

Specimens examined. — Total number 105, from localities as fol- 

Arizona: Grand Canyon, near Mountain Spring, 9; Holbrook, 36; Keain 
Canyon, 9 ; Painted Desert, Little Colorado River, 4. 

Colorado: Ashbaugh Ranch, 2; Coventry, 2; Grand Junction, 1 ; a Mesa 
Verde, 1 ; Plateau Creek, 1 . 

New Mexico: Cbaco Canyon 4. 

Utah: Bluff City, 26; Cainesville, 1; Henry Mountains (east base Mount 
Ellen), 1; Noland Ranch, 4; Uncompahgre Indian Reservation, 4. 


(PI. Ill, fig. 10.) 

Peromyscus stephensi Mearns, Proc. T T . S. Nat. Mus., XIX, p. 721, July 30, 1899. 
Peromyscus petraius Elliott, Field Col. Mus., Zool. Ser., Ill, p. 244, Jan., 1904. — 
Lone Pine. California. 

Type locality. — " The lowest water, on the wagon road, in a can- 
yon, at the eastern base of the Coast Range Mts., San Diego Co., 
California, near the Mexican Boundary Line." 

Characters. — Similar to P. auripectus, but smaller and paler. 

Geographic distribution. — Rocky situations in the Lower Sonoran 
zone from northeastern Lower California northward to the desert 
valleys and ranges of the Death Valley region and eastward across 
southern Nevada to southwestern Utah and northwestern Arizona. 

Color. — General color much as in P. eremicus; ground color of 
upperparts pale ochraceous buff; facial region slightly grayish; a 
uniform mixture of dusky brownish covers upperparts except a 
narrow buff lateral line; underparts white or creamy white, occa- 
sionally with a buff pectoral spot. In worn pelages the amount and 
intensity of the dusky admixture varies greatly; in moderate wear 

Collection of E. R. Warren. 


the dusky changes to cinnamon and in extreme wear it almost en- 
tirely disappears, leaving only clear pale buff; the eyelids and whis- 
kers are dusky at all times. 

Skull. — Similar to that of auripectus but smaller; lighter and more 
frail throughout; zygomata much compressed anteriorly; rostrum 
attenuate ; molar teeth small. 

Measurements. — Type: Total length, 193; tail vertebra, 108; hind 
foot, 19. Average of 10 adults from Funeral Mountains, California : 
Total length, 170 (161-176) ; tail vertebra?, 94 (88-101) ; hind foot, 
20; ear from notch (dry), 16 15.3-16.5). 

Type specimen. — No. 61026 U. S. National Museum. 9 adult. 
May 9, 1894. Collected by Dr. E. A. Mearns. The specimen is in 
very worn pelage and therefore very pale; moreover, it is slightly 
overstuffed, which also increases paleness. The specimen is perfect 
except for two slight breaks in the skull, one in the right zygoma 
and the other in the left side of the basioccipital. 

Remarks. — This species is not definitely distinguishable from P. 
eremicus by color alone, although one who has handled large numbers 
of each may become sufficiently expert to discriminate them accurately 
in the majority of cases. The hairiness of the tail is usually sufficient 
to distinguish stephensi from eremictis, and a comparison of skulls 
usually removes all doubt. The long attenuate rounded rostrum of 
stephensi is always easily recognized in contrast to the high, flat 
rostrum with truncate nasals and long premaxillse of eremicus. The 
species is not numerously represented from the region of the type 
locality, but was taken in very large numbers in the desert ranges of 
eastern California by the Death Valley Expedition. These northern 
specimens, when in the same pelage, do not differ from the type in 
color. The type has a somewhat longer tail and shorter hind foot 
than the average of the northern specimens, but may be exactly 
matched among them, so there seems no reason for recognizing P. 
petraius, the type of which has been examined, P. stephensi inter- 
grades with P. crinitus as well as with P. auripectus. In the immense 
series of this form examined great variation in shade of color occurs, 
due to the various stages of wear in the pelage. The extent to which 
dusky becomes cinnamon or brown or other shades results in endless 
slight variations in general effect. Some series are entirely bright 
cinnamon ; others are pale buffy gray mixed with dusky, etc. 

Specimens examined. — Total number 449, from localities as 
follows : 

Arizona: Dolan Spring, 2; Tinajas Altas, 1. 

California: Amargosa River, 2; Argus Mountains, 13; Barstow, 6; Ben- 
ton, 1; Burns Canyon, San Bernardino Mountains, 1; Cave Camp, 
Pahrmnp Valley, G; Copper City, 5; Coso, 2; Coso Mountains, 2; 
Daggett, 1; Death Valley, 3; East base Coast Range, Mexican 


boundary, 1; Emigrant Spring, 13; Funeral Mountains, 17; Granite 
Springs, 5; Grapevine Spring, 2 ; Independence Creek, 2; Inyo Moun- 
tains, 7 ; Kern River, 15 in. northeast of Bakersrield, 1 ; Little Owens 
Lake, 7; Lone Pine, 33; Lone Willow Spring, 21; Long Valley, 1; 
Ludlow, 4; Morans, 1; Morongo Pass, 2; Maturango Spring, 14; 
New York Mountain. 4; Oro Grande, 14; Owens Lake, 4; Palm 
Springs, 8; Pamirnint Mountains*, 113; Pilot Knob, near Yuma, 1; 
Providence Mountains, 2: Resting Springs, 10; San Felipe Valley, 2; 
Saratoga Springs, 17 ; Shepherd Canyon, 8 ; Twelve Mile Spring, 4 ; 
Victor, 5; 35 miles south of Victor, 2; Warrens Well, 1; White 
Mountains, 1 ; Wild Itose Spring, 6. 

Lower California: Canyon Esperanza, 2; Cocopah Mountains, 2; Signal 
Mountain, 1.° 

Nevada: Ash Meadows, 3; Charleston Mountains, 16; Gold Mountain, 2; 
Grapevine Mountains, 13; Pahroc Spring, 2; Pahrump Valley, 9; 
Thorp Mill, 8. 

Utah: St. George, 11; Santa Clara, 2. 

Key to subspecies of Peromyscus californicus. 

Size larger; molars heavier. Central California P. californicus 

Size smaller; molars weaker. Southern and Lower California P. c. insignia 


(PI. VI, fig. 5; pi. VIII, fig. 4.) 

Mils californicus Gambel, Proc. Acad. Nat. Sci. Phila., IV, p. 78, August, 1S4S. 
[Hesperomys] parasiticus (Cooper), Baird, Mamm. N. Am., U. S. Pac. It. R. 

Reports, VIII, p. 479, 1857. — Nomen nudum. 
P[eromyscus] californicus Thomas, Ann. & Mag. Nat. Hist, ser. G, XIV, p. 364, 

Nov., 1894. 

Type locality. — Monterey, California. 

Geographic distribution. — Upper Sonoran and Transition zones of 
the coast region of California from San Francisco Bay south to the 
vicinity of Santa Barbara, where intergra elation with subspecies in- 
signis occurs. 

General characters. — Size very large, exceeding all other species 
in the United States ; color dark, buffy pectoral spot frequently pres- 
ent ; pelage long and lax; sole of pes naked to end of calcaneum (oc- 
casionally very narrowly naked or covered medially by ends of 
lateral-rooted hairs on tarsus between end of metatarsals and end 
of calcaneum) ; tail longer than head and body, well haired, but an- 
nulations not thoroughly concealed; ears very large and leafy, very 
thinly haired within and without ; skull of moderate size and regu- 
lar proportions; first and second upper molars without cusplets be- 
tween outer angles between tubercles. 

Color. — Topotype Xo. 31978 (Fresh winter pelage; date Oct. 1; 
second molt nearly complete) : Ground color of upperparts russet 
(more grayish on back and more ruddy on sides) blending with 

a Collection of F. Stephens. 


broccoli brown on head, except checks, which are bordered below by 
a light line of russet; orbital ring dusky; upperparts everywhere 
much mixed with black, which is somewhat concentrated in middle 
of back; sides much paler in general effect than back; underparts 
creamy white, except base of tail, which is russet ; forelegs pale rus- 
set, becoming dusky near end of carpus; maims white; pes white 
with a short dusky stripe extending down from hind leg: tail bicolor, 
black and white not sharply contrasted. Worn summer pelage (rep- 
resented by Xo. 35405, Mountain View, Calif., Aug. 3) : Upperparts 
cinnamon heavily mixed with Mars brown, back only slightly darker 
than sides ; underparts k bluish ' white. 

Skull. — Size large; proportions regular; nasals moderate, rela- 
tively shorter than in P. sitkensis; braincase rather full; audital 
bulla? large; molar teeth heavy; enamel pattern as shown in partly 
worn teeth with two simple involutions on outer sides of first and 
second molars. 

Measurements. — Average of 10 adult topotypes: Total length, 
243 (238-260) ; tail vertebra-, 133 (127-146) ; hind foot, 27 (26-29) ; 
ear from notch (dry), 22.3 (21.3-23.5). 

Type specimen. — The specimen upon which the original descrip- 
tion of Mus californicus was based was lost before it reached any 
museum. In his description, Gambel says of it : 

I captured but a single specimen of this species in a field near Monterey, 
upper California, which, with those of the former [Dipodomys agiMs], I had 
the misfortune to lose. 

Remarks. — This mouse easily ranks as the largest species of the 
genus in the United States. The only other California species with 
which it might be confused is P. truei, as a very large example of 
truei is sometimes found which in size approximates many small 
examples of californicus. This is particularly true of the skulls, 
which are sometimes almost exactly alike in size and contour. They 
may always be distinguished, however, by the dentition, as the rudi- 
mentary cusps in the lateral angles of the molars are well developed 
in truei and entirely absent in californicus. Specimens from within 
the range above defined vary somewhat. Those from Monterey, the 
type locality, fortunately represent neither extreme as regards either 
size or intensity of color. The characters of californicus which dis- 
tinguish it from insignis (large size and dark color) are accentuated 
in specimens from Boulder Creek and other localities in the Santa 
Cruz Mountains. On the other hand, specimens from several localities 
in Santa Barbara, Ventura, and Los Angeles counties are referred 
to californicus, though unquestionably all are intermediate, and possi- 
bly some specimens from this region will prove to be actually more 
like insignis than californicus. Two immature and otherwise un- 
satisfactory specimens from Three Rivers and Cain Flat are some- 


what doubtfully referred to calif ornicus. These are the only records 
of the species from any part of the Sierra Nevada. 

As shown by Allen, a females of this species are slightly larger than 
males, as in most species of the genus. The presence of a fulvous 
pectoral spot is more usual in calif ornicus than in insignis. In many 
individuals it is entirely absent, while others show all degrees of its 
development from a mere trace to entire occupation of the ventral 
surface. The tendency to a white tip at end of tail is also somewhat 
irregular. In a series of 18 adults from Monterey, 4, or about 20 per 
cent, have white-tipped tails, which is the same percentage (40 out of 
207) noted by Allen (loc. cit.) in a very large series. As a rule the 
amount of white is small, but the tails of No. 35408 from Mountain 
View and No. 107821 from Pescadero Creek have fully an inch of 
terminal white. The pelage changes of this species are not peculiar, 
but on account of the size of the animal they may be followed more 
readily than in the smaller species. The juvenile pelage is slate gray 
(No. 5, Ridgway). The first evidence of the adolescent pelage is a 
faint fulvous wash on the sides; this increases in intensity until the 
sides are clothed in new glossy pelage, while the middle of the back 
still remains dull plumbeous. The growths on the two sides usually 
approach each other and finally unite in the middle of the back, the 
occiput, nape, and rump being the last parts to acquire the new coat. 
In many cases this method of change is followed exactly and the line 
of demarcation between the juvenile and first adult pelage is sharply 
distinct from beginning to end and the whole process is easily fol- 
lowed; in others the last stages of change are almost imperceptible. 
This first adult condition of pelage is closely similar to the later full 
pelage as described above under Color. It is paler and less rufescent 
than the full pelage ; the light subterminal zone of color in the hairs 
which determines the general body color is narrower, thus allowing 
more of the plumbeous undercolor to show through. The black tends 
to be well distributed instead of being somewhat concentrated in the 
middle of the back as in the full pelage. Immature pelages are to be 
found in almost every series of specimens, as the animals seem to 
breed throughout the year. Specimens of equal-sized young in soft 
plumbeous pelage have been examined as follows: Jan. 2 (Santa 
Paula) ; Feb. 18 (Santa Monica) ; April 29 (Twin Oaks) ; May 11 
(San Diego) ; June 25 (Bear Valley) ; Aug. 1 (Mountain View) ; 
Oct. 25 (Santa Cruz Mountains) ; Nov. 12 (Dulzura) ; Dec. 27 (Pa- 
cific Grove). This includes nearly every month in the year and both 
northern and southern localities. 

The molt of the adult is somewhat irregular and does not seem to 
be entirely dependent upon season. The majority of specimens seem 

°Bull. Am. Mus. Nat. Hist., N. Y., VIII, p. 2G7, 1S9G. 


to indicate two molts, one in early summer and another in late fall. 
Both of these are very insidiously accomplished. The winter pelage 
is acquired late in October or November and persists until the follow- 
ing spring. 

The name parasitic mouse, first given to this species by Doctor 
Cooper, refers to the habit of living in or about the large ' nests ' 
or ' houses ' of Neotoma fuscines. Other mice also inhabit these 
places and P. calif ornicus is found elsewhere ; moreover, it is probable 
that only deserted nests are frequented, so that the species is not 
strictly speaking parasitic. As the habit is very characteristic of 
P. calif ornicus, however, the name may well be retained. 

Specimens examined. — Total number 698, from the following lo- 
calities : 

California: Alum Rock Park, 172; Arroyo Seco River, near Paraiso 
Springs, 3 ; Bear Valley, San Benito County, 9 ; Bear Basin, Monterey 
County, 3 ; Berkeley, 14 ; Big Basin, Santa Cruz County, 1 ; Big Pine 
Mountain, 1 ; a Boulder Creek, 5 : Cain Flat, Mineral King Road, 1 ; 
Calabasas, 1 ; Carmel River, 14 ; Carpenteria, 2 ; Cone Peak, Monterey 
County, 4 ; Fort Tejon, 2 ; Fremont Peak, Gabilan Range, 4 ; Gaviota 
Pass, 1; near Gilroy, 1; Hueneme (10 miles east), 3; Indian Canyon, 
2 ; a Indian Valley, Monterey County, 4 ; King City, 1 ; La Honda, 31 ; 
Las Virgines Creek, 2 ; Little Pine Canyon, 2 ; a Mansfield, 1 ; May field, 
2; Menlo, 2; Mono Flats, 2;« Monterey, 20; Mount Hamilton, 21; 
Mountain View, 7: Nordboff, 1; Paeheco Pass, 4; Pacheco Peak, 6; 
Palo Alto, 2 ; Paso Robles, 4 ; Upper Pescadero Creek, 14 ; Pillareitos 
Lake, San Mateo County, 1: Pine Valley, near Tassajara Springs, 2; 
Point Pinos, 2 ; Portola, 242 ; Posts, 3 ; Pozo, 1 ; San Luis Obispo, 5 ; 
San Mateo, 2 ; San Pablo Creek, Contra Costa County, 1 ; San Rafael 
Mountains, 2; a near San Simeon,!; Santa Barbara,!; Santa Monica, 
3; Santa Paula, 12; bead of Santa Ynez River, 3; a Stanford Univer- 
sity, 7 ; Soledad, 1 ; Sur, 2 ; Sur River, near moutb, 4 ; Tassaiara 
Springs (6 miles soutb), 10; Tejon Canyon, 4; Tbree Rivers, 1; 
Ventura Rivei*, 7; Woodside, San Mateo County, 7; Zaca Lake, 2. a 



Peromyscus insignis Rboads, Proc. Acad. Nat. Sci. Pbila. (1895), pp. 33-34, 

Mar. 19, 1895. 
Peromyscus califomicus insignis Mearns, Bull. No. 56, U. S. Nat. Mus., p. 429, 

Apr. 13, 1907. 

Type locality. — Dulzura, San Diego County, Calif. 

Geographic distribution. — Upper and Lower Sonoran zones of the 
western valleys and foothills of southwestern California and thence 
south into northern Lower California. 

Characters. — Similar to Peromyscus califomicus, but slightly 
smaller and paler; skull smaller; molar teeth lighter. 

° Santa Barbara County. 


Color. — Very similar to that of P. calif ornicus, but averaging very 
slightly paler; rufous shades generally less intense; pectoral spot 
usually faint or absent; rufous at base of tail nearly obsolete; plum- 
beous undercolor paler; black-tipped hairs in middle of back less 

Skull. — Similar to that of P. calif ornicus but smaller; teeth smaller 
and lighter; anterior palatine foramina shorter; audital bullae very 
slightly smaller. 

Measurements. — Average of 6 adult topotj^pes: Total length, 233 
(220-245); tail vertebra?, 134 (124-140); hind foot, 25; ear from 
notch (dry), 20.3 (20-20.7). 

Type specimen. — No. 8308 Collection Academy of Natural Sciences, 
Philadelphia; formerly No. 1308 Collection of S. N. Rhoads. 
$ adult. August 21, 1893. C. H. Marsh. Skin in good condition, 
underparts slightly greasy ; skull with interparietal slightly indented 
and broken. 

Remarks. — Typical insignis may be easily distinguished from typ- 
ical calif ornicus by its smaller size and light skull and teeth. The 
difference in color is slight, and therefore comparison should be con- 
fined to specimens absolutely comparable as regards both age and 
pelage. Fully adult specimens in winter pelage may be found that 
are practically indistinguishable. The first or young adult pelage 
of insignis is usually paler than in calif ornicus; the worn and wear- 
ing summer pelage is also a trifle paler. However, it is possible to 
find specimens of each form so nearly alike in all pelages that it seems 
only safe to say that the tendency to a gray phase is stronger in 
insignis. P. insignis is more apt to be mistaken for P. truei than is 
P. califomicus, but as stated under califomicus, the dentition fur- 
nishes characters which are unmistakable. 

/Specimens examined. — Total number 251, from localities as follows : 

California: Banning, 2; Cajon Pass, 7; Campo, 6; Coabuila Mountain, 
Riverside County, 1; Densmores, Riverside County, 1; Dulzura, 80; 
Glendora, 3; Grapeland, 3; Jacumba, 5; Jaruul Creek, 2; La Jolla, 3; 
La Musa, 1; Mountain Spring, 2; Radee, 3: San Bernardino Peak, 
5; San Bernardino Valley, 2; San Diego, 10; San Gabriel Mountains, 
1; Santa Ana Mountains, 1; Santa Ysabel, 16; Ternescal, 3; Twin 
Oaks, 18 ; Walker Basin, 1 ; « Witeb Creek, 5. 

Lower California: El Rayo, 2; Ensenada, 3; 20 m. east of Ensenada, 1; 
Juneolito Spring, 1 ; Las Eneinas, 8; Nacboguero Valley, 22; Rancbo 
Viejo, 2; Rosarito, 2; San Antonio, 6; San Pedro Martir Mountains, 
2 ; San Quentin, 1 ; San Tehno, 4 ; San Ysidro Rancb, 1 ; Tecate Val- 
ley, 14 ; Trinidad, 1. 

Key to subspecies of Peromyscus eremicus. 

Habitat southern California. 

Paler; underparts usually white. East of coast ranees P. eremicus 

Darker; underparts usually huffy. West of coast ranges /'. e. fraterculus 

° Collection of F. Stepbens. 


Habitat mainland of Lower California. 
Underparts usually white. 

Paler; t.-ill shorter; molars large. Northeastern P. eremicus 

Darker; tail longer; molars smaller. Southern P. e. eva 

Underparts usually huffy with a pectoral spot. Northwestern P. e. fratcrculits 

Habitat islands off the coast of Lower California. 

Underparts with an ochraceous buff pectoral spot. 

Size larger. Cedros Island P. e. cedrosensis 

Size smaller. Espiritu Santo Island P. e. insuUcola 

Underparts without pectoral spot. 

Size larger ; upperparts chiefly ochraceous. Ceralbo Island. 

P. c. (iriiis 
Size smaller; upperparts chiefly grayish. Margarita Island. 

P. e. polypoliua 
Habitat Arizona, New Mexico, Texas, and Mexico. 

Tail more or less bicolor. 

Color paler; underparts white P. eremicus 

Color darker ; underparts white, often with a buffy 

pectoral spot P. e. anthonyi 

Tail dusky all around. Mexico P. e. phoeurus 

PEROMYSCUS EREMICUS (Baird). Desert Mouse. 

(PI. Ill, fig. 11; pi. VI, fig. 0; pi. VII, fig. 4; pi. VIII, fig. 3.) 

Hesperomys eremicus Baird, Mamm. N. Am., Pac. R. R. Repts., VIII, pp. 479- 

480, 1857. 
Peromyscus eremicus Allen, Pull. Am. Mus. Nat. Hist., X. Y., VII, p. 226, June 

29, 189. r >. 
Peromyscus eremicus arenarius Mearns, Proc. U. S. Nat. Mus., XIX, p. 138, May 

25, 1896.— Near El Paso, Tex. ^ 

Peromyscus merriami Mearns, Proc. U. S. Xat. Mus., XIX, p. 138, May 25, 1896. 

Sonoyta, Sonora, Mex. 

Type locality. — Old Fort Yuma, Calif., opposite Yuma, Ariz. 

Geographic distribution. — Lower Souoran zone of southeastern 
California and northeastern Lower California east of the mountain 
raHges as far south as the vicinity of San Luis Bay; eastward to 
western Texas, and south to border States of eastern Mexico ; north- 
ward along the Colorado River, at least to the vicinity of the mouth 
of the Little Colorado, also extending from the Colorado River 
along the Virgin Valley to St. George, Utah, and northwestward, 
crossing southern Nevada, to the Death Valley region of California. 

General characters. — Size medium ; tail decidedly longer than head 
and body, finely annulated and closely covered with short hairs, with 
very slight or no pencil at tip; ears relatively large and leafy, very 
thinly haired or almost naked; sole of hind foot naked to end of 
calcaneum, at least medially; pelage soft and silky; color generally 
shades of rather pale buff; black lining and grizzling exceedingly fine 
aid uniformly distributed over upperparts, not concentrated medially. 

Color. — Adult topotype No. 60172, collected April 3, still in winter 
pelage: Ground color of upperparts ochraceous buff; entire dorsum 
with a fine sprinkling of dusky, this not concentrated at any point. 



[no. 28. 

but uniformly distributed; a broad lateral line pure ochraceous buff; 
sides and top of head slightly grayish; tail dusky above, whitish be- 
low; underparts pure white or slightly tinged with yellowish or buff; 
traces of pectoral spot sometimes present. As the pelage wears, the 
black mixture in the upperparts becomes paler (brownish) and less 
distinct, and the ground color shows through more strongly. The 
lateral line is less sharply contrasted and gradually the entire upper- 
parts become a dingy butf faintly sprinkled with cinnamon. Ado- 
lescent pelage: Similar in general to adult, but decidedly less buffy 
and more dusky, producing a general effect of pale drab; lateral line 


Skull. — Size me- 
dium: braincase 
rather high and 
somewhat elongate ; 
infraorbital region 
well developed, 
much heavier than 
in P. stephensi/ 
nasals rather broad, 
slightly concave 
near posterior end- 
ings; maxillaries 
always ending pos- 
terior to nasals: 
audita! bullae and 
anterior palatine 
foramina of mod- 
erate size. 

Measurements. — 

Fig. 11. — Distribution of Peromyscus eremicus and subspecies. Avei*a°e of 10 

adults from northeastern Lower California, near the type locality: 
Total length, 183 (172-192) ; tail vertebras, 101 (94-108) ; hind foot, 
20.5 (20-21) ; ear from notch (dry), 17.5 (17.3-17.8). Three topo- 
types, respectively: 202, 193, 186; 107, 103, 96; 21, 21, 20. 

Type specimen. — The original description of this species was based 
on 6 specimens, 3 from Fort Yuma, Cal., and 3 from Colorado Bot- 
tom, California, an indefinite locality, doubtless very near Yuma. 
Three of these are still in the U. S. National Museum in more or less 
imperfect condition. Xo. ifH? which, being the first mentioned, 
might naturally be considered the type, is represented by fragments 
of the skull only, the mandibular rami, a portion of one maxillary, 
and 5 loose teeth. The skin evidently has been lost or mislaid since 
Baird's work was done. Xo. 2575, which is in effect the type, is 
still preserved in alcohol and is in fairly good condition, having lost 


but a small amount of hair on the sides and middle of the belly. Its 
skull has been removed and is practically perfect; the teeth are 
entirely unworn, indicating that the animal was scarcely adult. 
The third existing specimen, No. 1334, from Colorado Bottom, is a 
dry skin, somewhat distorted, but exhibiting the characters of the 
species very well ; the fourth, from the same locality, is at present 
in the Museum of Comparative Zoology, Cambridge, Mass. If 
Fort Yuma be considered the type locality of P. eremicus, and there 
seems to be no reason why it should not, the above-mentioned alco- 
holic specimen No. 2575 becomes the type to all intents and purposes. 
Remarks. — Typical Peromyscus eremicus occupies a comparatively 
extensive range in southern California, Arizona, New Mexico, and 
adjoining parts of Mexico, and is characteristic of the Lower Sonoran 
zone in this region. About the periphery of this range it intergrades 
with several more or less marked subspecies. More slightly char- 
acterized forms not recognized by name occur in several restricted 
areas, and throughout the range there are occasional slight variations 
in shade of color. It is easily distinguishable from the other species 
of the region, not only by its dentition, but by its long, terete, un- 
t ufted tail and naked heels. It is very similar in color to P. stephensi 
but that species is smaller and has a penicillate tail. It does not 
undergo marked changes of pelage, and it molts in the same manner 
as P. calif ormcus, of which it is scarcely more than a pale miniature. 
The form called P. eremicus arenarius appears to be too slight for 
recognition by name. A good series from the Franklin Mountains, 
Texas, near the type locality of arenarius reveals not the slightest 
difference in color from typical eremicus in exactly corresponding 
pelage. The only character is an exceedingly slight average de- 
crease in the size of the ears. Another incipient form occurs in 
southern Utah, Nevada, and the Panamint and Death Valley region 
of California. The so-called P. merriami is, indeed, larger than 
typical eremicus, or at least larger than the majority of specimens 
from the habitat of typical eremicus, but only slightly larger, and 
not in the least different otherwise. The larger specimens of a series 
from one locality, Sonoyta, have been selected and called merriami, 
while the remaining smaller ones are unquestioned eremicus. Among 
the ten specimens identified by the original describer as merriami 
absolute uniformity in size does not obtain, or in other words there 
is a gradation from the smallest eremicus to the largest ' merriamV 
At other localities throughout the range of eremicus occasional speci- 
mens have been taken which are larger than the average and about 
the size of the Sonoyta specimens. Undeniably there are more large 
individuals from Sonoyta than from any other locality, but it seems 
too much of an assumption that they are specifically distinct. Speci- 

66268— No. 28—09 1G 


mens from Calamahue, Yubay, and neighboring localities in north- 
east Lower California are tentatively referred to eremicus although 
their slightly longer tails and creamy nnderparts seem to indicate 
a decided tendency toward P. e. era. 

Specimens examined. — Total number 824, from localities as 
follows : 

Arizona: Adonde, 11 ; Beale Spring, 2; Big Sandy Creek, 2; Bill Williams 
River, 2: Colorado River at Boundary Monument No. 204, 16; Dolau 
.Spring, 4; Ehrenberg, 1 ; Fort Grant, 7; Fort Huachuca, 8 (approach- 
ing anthonyi) ; Fort Lowell, 3; Fort Mohave, 4; Gila City, 9; Grand 
Canyon, 12; Granite Mountains, near Tule Wells, 1; Harper Ferry, 
5; La Osa, 11; Little Meadows, 2; Mineral Park, 4; Mud Spring, 15, 
Nortons, 2; Painted Desert. 1: Phoenix, 2; San Pedro River, 1; 
Tinajas Altas, 9; Tucson, 1; Mountains near Tucson, 5; Tule Wells, 
2 : Willow Spring, 1 ; Yuma, 7. 

California: Banning, 11; Barstow, 19; Big Laguna, 1; Colorado Bottom, 
2: Daggett, 1; Death Valley, 3: Fort Yuma. 13; Furnace Creek, 5; 
Grapevine Ranch, 8; La Puerta, 10; Mohave Desert, east of Morongo 
Valley, 2; Morongo Pass, 10; Needles, 0; New River, 1; Oro Grande, 
1; Palm Groves. 6; Palm Springs, 47; Pauamint Mountains, 3; 
Pananiint Valley, 36; Pilot Knob, 5; Providence Mountains, 9; Rest- 
ing Springs, 59; San Felipe Canyon (approaching fraterculus) , 11; 
San P^elipe Valley, 1; 12-mile Spring, 2: Vallecitos, 2; Victorville, 1; ° 
Warrens Well, 2; Whitewater, 8. 

Nevada: Amargosa River, 4; Ash Meadows, 2S; Bunkerville, 2; Charles- 
Ion Mountains, 0; Colorado River, Lincoln County, 2; Pahrump 
Valley, 32; St. Thomas, 1; Vegas Valley, 0. 

New Mexico: Carlsbad. 5; Jarilla, 1; Organ Mountains, 7; San Andres 
Mountains, 6; Tularosa, 1<»: Mai Pais Spring, 25 miles north of 
Tularosa, 3. 

Texas: Boquillas, 1; Chinate Mountains, 1; Comstock, 2; East Painted 
Cave, 1; Franklin Mountains, near El Paso, 19; Marfa, 10; near El 
Paso, 21; Langtry, 2: Presidio County, 3: Sierra Blanca, 2; Ter- 
lingua, 1. 

Utah: St. George, 7; Santa Clara, 9. 

Chihuahua: Chihuahua, 31; Escalou, 10; near Fort Bliss, Tex., 1; Santa 
Rosalia, 4: Torreon, 1. 

Coahuila: Carneros, 2 (aberrant) ; Jaral, 8: Jimulco, 6 (approaching 
phwurus) ; Monclova, 8. 

Durango: Inde, 1. 

Lower California: Agua Dulce. 1 : b Black Mountain, 1; Calamahue, 4; b 
Cocopah Mountains, 6: Esperanza Canyon. 12 (approaching frater- 
culus) ; Gardner Lagoon, 2; Hardy River, 5; Matomi, 5; Palomar, 
4 ; Parral, 6 : The Remada, (5 : Rosarito Divide, 1 ; San Francisquito, 
16 ; 6 Seven Wells, 1 : Yubay, 5. 6 

Nuevo Leon: Sierra Encarnaciou, 1 (aberrant). 

Sonora: Cerro Blanco, 3; Poso de Luis, (i ; Providencia Mines, 11; Quito- 
baquita, 14 ; Sonoyta, 15. 

"Collection of J. Grinnell. 6 Approaching /'. <. era. 



Vesperimus fraterculus Miller, Am. Nat., XXVI, pp. 261-203, March, 1892. 
Sitomys eremicus fraterculus Rhoads, Am. Nat., XXVII, p. 833, Sept.. 1893. 
Sitomys herroni Rhoads, Am. Nat., XXVII, pp. 832-833, Sept., 1893: — Reche 

Canyon, San Bernardino County, Calif. 
Sitomys herroni mgellus Rhoads, Proc. Acad. Nat. Sci. Phila., pp. 2.".T-2."».s, 

Oct. 23 1894. — AV. Cajon Pass, San Bernardino County, Calif. 
[Peromy8CUS] fraterculus Trouessart, Catal. Mamm. pt. Ill, p. 515, 1897. 
Peromyscus eremicus fraterculus Allen, Bull. Am. Mus. Nat. Hist., N. Y., X, 

p. 154, 1898. 
Peromyscus homochroia Elliot, Field Col. Mus., Chicago, Zool. Ser., Ill, pp. 

158-9, Apr., 1903. — San Queutin, Lower California. 

Type locality. — Dulzura, San Diego County, Calif. 

ideographic distribution. — Extreme southwestern California, west 
of the mountains from the vicinity of Los Angeles south to north- 
western Lower California. 

General characters. — Similar to P. eremicus, but decidedly darker; 
more reddish brown in summer, more blackish in winter; underparts 
creamy or buff instead of pure white; tail somewhat longer. 

Color. — Cotype in winter pelage: Ground color of upperparts 
cinnamon rufous richly sprinkled with black, which is somewhat 
concentrated in middle of back; head with more or less grayish, 
particularly in postorbital region; underparts creamy white with a 
small rufous pectoral spot. No. 34086, San Diego, Calif., in slightly 
worn 'left-over' winter pelage: Ground color cinnamon-rufous, as 
in winter pelage; tips of hairs not black, but brown or brownish 
dusky, producing a more rufescent general effect than in the winter 

Skull. — Practically as in P. eremicus. 

Measurements. — Average of 3 specimens — 2 cotypes and 1 topo- 
type: Total length, 191; tail vertebra-, 112; hind foot, 20. 

Type specimen. — A male and a female type were designated by the 
describer of this species in accordance with the one-time idea that 
this was desirable. At present these may be considered as cotypes of 
equal importance, or the male may be selected for a type, as has been 
done frequently by ornithologists in similar cases. Both specimens. 
Nos. \\\\ ( $ ) and Vs¥ ( 9 )? formerly in the private collection of 
Gerrit S. Miller, jr., are now in the British Museum. 

Remarks. — P. e. fraterculus is a very well-marked subspecies. 
Typical specimens are so much deeper colored than eremicus that they 
are recognizable at a glance. It is geographically separated from 
eremicus by a more or less continuous range of mountains, in the in- 
terdigitating canyons of which intermediate specimens are found, 
some nearer to fraterculus and others referable to en micus. Among 
such intermediates are those from Reche Canyon which have been 
called * herroni ' and which are easily referable to fraterculus unless 


such slight intermediates without definite range arc to be recognized. 
The type of herroni is nearer fraterculus than most others from the 
San Bernardino Mountains, since it has the entire underparts suffused 
with buff, a condition never found in typical eremicus. '/'. h.nigellus ' 
appears to be identical with fraterculus. P. e. fraterculus ranges 
south along the coast of Lower California and meets P. e. era, the 
specimens called ' propinquus ' being almost exact intermediates. 
Sped mens examined. — Total number 230, from localities as follows : 

California: Aguanga, 3; Burbank, 1 ; Cajon rass, 4; Campo, 3; Chihua- 
hua Mountains, San Diego County, 1; Dulzura, 10; Glendora, 1; 
Hueneme (9 m. east). 2: Jamul Creek, near El Nido, 13; Jacumba, 
11: Lytle Creek, 1 (approaching eremicus); Mountain Spring, 11 
(approaching eremicus); Nordhoff, 1; Radec, 1; Recbe Canyon, 10 
(approacbing eremicus); Redlands, 1; Riverside, 10; Rose Canyon, 
San Diego Co., 4: San Bernardino, 2; San Bernardino Valley, 19 
(approaching eremicus); San Diego, 8: San Fernando, 5; Santa 
Ysalx'l, 8; Summit, Coast Range, San Diego County, 1; Temeseal, 2; 
Mouth Tia Juana River, 2; Twin Oaks, 2; West Riverside, 2. 

Lower California: Canyon Salado, 1; Ensenada, 4; Las Eneinas, 2: 
Nachoguero Valley, 1; Pinon, 2; Ranebo Viejo, 3; San Antonio, 7; 
Sau Antonio River, 8; San Fernando, 11; San Matias Spring, 9; San 
Quentin, 19; Socorro, 1; Tecate Valley, 14; Trinidad, 8; Valla- 
dores. 1. 


Peromyscus cedrosensis Allen, Bull. Am. Mus. Nat. Hist., N. Y„ X, pp. 154-155, 
Apr. 12, 1898. 

Type locality. — Cerros Island, off west coast of central Lower Cali- 

Geographic distribution. — Cerros Island, Lower California. 

General characters. — Similar to P. e. era ; color averaging slightly 
darker and richer; paler than in P. e. fraterculus ; ears smaller; skull 
slightly larger with longer nasals. 

Color. — Similar to that of fraterculus, but averaging paler; lateral 
line rather broad and conspicuous ochraceous buff; pectoral spot 
usually present; underparts buffy; tail slightly lighter below than 

Skull. — Much as in P. e. fraterculus, but with rostrum and nasals 
averaging longer and more slender; rostrum somewhat depressed; 
brainca'se high and rounded. 

Measurements. — Average of 8 topotypes: Total length, 193 (181— 
200); tail vertebra\ 110 (106-114); hind foot (dry), 20; ear from 
notch (dry), 16 (15.5-16.5). 

Type specimen. — 'No. if!!! American Museum of Natural History, 
New York. $ adult. April 1, 1897. A. W. Anthony. Skin in good 
condition; skull badly broken, lacking all the anterior part of the 
cranium ; rostrum, nasals, and upper molars in good condition. 


Remarks. — This insular form is almost identical in color with the 
mainland intermediates between fraterculus and eva. The material 
representing - it is in rather poor condition and it is difficult to observe 
any characters of importance. It is perhaps nearer in color to 
fractercuius than to eva, since its underparts are huffy with a well- 
marked pectoral spot. The color of the upperparts is intermediate. 
The rather elongate rostrum is perhaps the best character observable 
in the material at hand. 

Specimens era mined. — Total number 11, all from the type locality. 


Peromyscvs era Thomas, Ann. & Mag. Nat. Hist., Lond., Ser. 7, I, pp. 44-45, 

Jan., 1898. 
Peromyscus eremicus propmquus Allen, Bull. Am. Mus. Nat. Hist.. X. V., X, 

p. 354, Apr. 2, 189S.— San Pablo Point, lat. 27° 20' X., Lower California. 

Type locality. — San Jose del Cabo, Lower California. Mexico. 

Geographic distribution. — Lower Sonoran zone of the central and 
southern part of the peninsula of Lower California, from Cape St. 
Lucas north to the vicinity of latitude 29° N., meeting the ranges of 
P. eremicus and P. e. fraterculus. 

Characters. — Similar in general to P. e. fraterculus, but tail longer; 
pelage shorter and slightly harsher; color more rufescent ; ears av- 
eraging slightly smaller; general appearance of a small Oryzomys; 
skull essentially as in P. eremicus. 

Color. — Unworn pelage: Upperparts ochraceous buff copiously 
mixed with fine dusky lines uniformly distributed, except on lower 
sides; general effect of back between isabella color and cinnamon; 
lateral line usually distinct only from axillary region to hip. often 
widened on middle of side to a broad area of clear ochraceous buff; 
head, including nose, cheeks, and orbital region pale gray tinged with 
ochraceous; a narrow dusky orbital ring scarcely extending beyond 
eyelids; ears pale brownish, almost naked; underparts pure creamy 
white without pectoral spot ; tail usually dusky above and slightly 
paler below, often quite uniform blackish all around ; feet white, 
tarsal joints marked with dusky. Worn pelage: General effect of 
both sides and back bright ochraceous buff scarcely at all modified 
by the slight mixture of dusky cinnamon. 

Skull. — Essentially as in P. eremicus and P. e. fraterculus, but 
averaging smaller with a smaller, narrower braincase and weaker 

Measurements. — Average of ten adults from Santa Anita : Total 
length, 198 (185-218) ; tail vertebrae, 114 (100-128) : hind foot. 20.4 
(20-21) ; ear from notch (dry), 16.6 (15.6-17.2). 

Type specimen,— No. British Museum. $ adult. July 29, 
1896. Dane Coolidge. Specimen in good condition. 


Remarks. — This is one of the most strongly marked forms of the 
eremicus series. Its resemblance to a small Oryzomys or some of 
the Mexican species of Reithrodontomys, as originally noted by 
Doctor Thomas, is quite striking. However, it can be ranked only 
as a subspecies of eremicus, for complete Lntergradation is found 
both with typical eremicus and with P. e. fraterculus. The supposed 
relationship to aztecus hazarded by Thomas after Coues is therefore 
out of consideration. Specimens, from Cape St. Lucas northward to 
the vicinity of latitude 28° north are quite uniform in color and pre- 
serve the same general characters, the only important variation being 
in size. In this respect there is considerable variation in every series. 
The largest specimens are from Aguaje de Santana, from which lo- 
cality the largest individual presents the following measurements: 
Total length, 228 ; tail vertebrae, 188 ; hind foot, 22. Other specimens 
from the same and neighboring localities do not differ materially 
from specimens of eva from the type locality. The supposed form 
called ' P. e. propinquus ' proves to be almost exactly intermediate 
between eva and fraterculus. Such a form can not be characterized 
and it can not be restricted to a definite range. It is placed under era 
rather than fraterculus chiefly on account of its long tail. The diffi- 
culty of properly allocating such a form is well shown by a series of 6 
specimens from San Andres. Three of these have white underparts 
without pectoral spots as in era, while the remaining three have buffy 
underparts and pectoral spots as in fraterculus. The measurements, 
cranial characters, and color of upperparts are exactly intermediate. 
Specimens from Yubay, Calamahue, and San Francisquito appa- 
rently are intermediate between eva and typical eremicus and on the 
whole seem nearer eremicus. A skin without skull from Carmen 
Island may represent an undescribed form. 

Specimens examined. — Total number 100, from localities as 
follows : 

Lower California: Aguaje de Santana, 6; Calmalli, 2; Carmen Island, 1 ; 
Cape St. Lucas, 2 ; Comondu, 5 ; El Potrero, 3 ; La Faz, 1 ; Matancita, 
2; Paso Hondo, 1; Peseadero, 1; Playa Maria Pay, 2 (approaching 
fraterculus) ; San Andres, 6 (approaching fraterculus) ; San Ignacio, 
4; L'o in. west of San Ignacio, 9; San Jorge 0; San Jose del Cabo, 
!>: San Pablo Point, 4; Santa Anita, 23; Santa Clara Mountains, 2; 
Sierra Laguna, 4; Tres Pachitas, 4; Turtle (or San Bartolome) 
Pay. 3. 


Type from Espiritu Santo Island, off east coast of southern Lower California, 
Mexico. No. 147010 U. S. National Museum, Biological Survey Collection. 
$ adult. Feb. 9, 1900. E. W. Nelson and E. A. Goldman. 

Geographic distribution. — Confined to Espiritu Santo Island. 
Lower California, 


Characters. — Similar to P. e. era, but color slightly darker; pec- 
toral region with an elongate stripe of ochraceous buff. 

Color. — Much as in P. e. era, but somewhat darker throughout; 
upperparts a deeper shade of ochraceous buff and mixture of dusky 
more copious, producing a more vinaceous general effect ; underpa it s 
creamy white with a sharply defined elongate pectoral stripe extend- 
ing backward to front of abdomen; tail chiefly dusky, scarcely 
lighter below than above. 

Skull. — About as in P. e. eva; narrower and lighter, with weaker 
molars than in arius. 

Measurements. — Two adult topotypes, respectively: Total length, 
196, 200; tail vertebrae, 115, 113; hind foot, 20, 19.5; ear from notch 
(dry), 16.5, 10.7. 

Remarks. — Although but few specimens from Espiritu Santo 
Island are available, they are so obviously different from P. e. era of 
the adjacent mainland that it seems necessary to name them. The 
prominent pectoral spot and slightly darker upperparts distinguish 
them at once from typical era, but in color they are very similar to 
specimens which are intermediate between eva and fraterculus. From 
these, however, they differ in having smaller skulls and weaker 

Specimens examined. — Total number 3, all from the type locality. 


Type from Ceralbo Island, off east coast of southern Lower California, Mexico. 
No. 147024 U. S. National Museum, Biological Survey Collection. § adult. 
Feb. 13, 1JMM5. E. W. Nelson and E. A. Goldman. 

Geographic distribution. — Confined to Ceralbo Island, Lower Cal- 

Characters. — Similar to P. e. era, but size slightly larger; ears 
smaller; color of underparts buffy instead of pure white; skull rather 
larger, with molar teeth relatively heavy. 

Color. — Upperparts essentially as in P. e. eva, chiefly ochraceous 
buff mixed wth fine lines of dusky, averaging slightly darker and 
richer than in era; entire underparts except throat and inguinal 
region cream buff; tail quite definitely bicolor, blackish brown above, 
dull whitish below. 

Skull. — Similar to that of P. e. era, but larger and heavier; inter- 
parietal rather larger; molar teeth decidedly larger and heavier, 
about equaling those of fraterculus. 

Measurement*. — Average of 10 adult topotypes: Total length, 194 
(186-209) ; tail vertebrae, 105 (100-116) ; hind foot, 21.6 (21.5-22) ; 
ear from notch (dry), 14.5 (13.4—16). 

"arius, out of the way: remote: unfrequented. 


Remarks. — The principal characters distinguishing this form are 
its rather large size, small cars, buffy instead of white nnderparts, 
and large teeth. It is represented by a good series in which these 
characters are quite constant. Although the underparts are largely 
buffy, there is no indication of a pectoral spot. This form, therefore, 
differs from insulicola of Espiritu Santo Island in this respect as well 
as in its larger skull and teeth, etc. 

Specimens examined. — Total number 17, all from the type locality. 


Type from Margarita Island, off west coast of southern Lower California. No. 
4 146074 U. S. National Museum, Biological Survey Collection. t $ adult. 
Nov. 30, 1905. E. W. Nelson and E. A. Goldman. 

Geographic distribution. — Confined to Margarita Island, Lower 

Characters. — Somewhat similar to P. e. eva, but color much more 
grayish; skull with rostrum more depressed; braincase shorter and 
more inflated. 

Color. — Unworn pelage: Upperparts from head to rump mixed 
gray, dusky, and pinkish buff, gray predominating on head, shoulders, 
and back and buffy becoming stronger toward rump ; upper sides like 
back; lower sides broadly pinkish buff or pale ochraceous buff, this 
being reduced to a narrow streak on lower cheeks; underparts pale 
cream buff, never so nearly white as in P. e. eva; pectoral spot rarely 
developed; feet white, tarsal joints dusky, tail dusky above, dull 
whitish gray often mixed with dusky below. Worn pelage: Less 
grayish than unworn pelage; general effect of upperparts pinkish 
buff considerably modified by dusky and gray. 

Skull. — Similar in general to that of P. e. eva, but rostrum more 
slender and more depressed ; infraorbital part of zygomata weaker 
and more compressed; braincase relatively shorter, broader, deeper, 
and more inflated ; molars slightly larger. 

Measurements. — Average of 10 adult topotypes: Total length, 192 
(183-200) ; tail vertebra?, 109.5 (100-117) ; hind foot, 19.5 (19-20) ; 
ear from notch (dry), 15.7 (14.6-16.8). 

Remarks. — This form, like margaritae of the maniculatus group, 
is well distinguished from its relatives of the mainland. Its deriva- 
tion from P. e. eva is scarcely to be doubted, however, and variation 
is occasionally sufficient to nearly or quite cover the characters shown 
hy the majority of specimens. The gray color is quite distinctive, 
the head being nearly of the same gray color as usual in the eremicus 
group, but this color is continued on the shoulders and back, and the 
ochraceous is largely confined to the rump and lower sides. The 
back is a peculiar ' peppery ' mixture of gray and dusky with slight 
tinges of buff. 

Specimens examined. — Total number 22, all from the type locality. 




Wesperomys (Vespertmus) anthonyi Merriam, Proc. Biol. Soc. Wash., IV, pp. 

5-7, Apr. 15, 1887. 
[Peromyscus] anthonyi Trouessart, Catal. Mamm., Pt. Ill, p. 517, 1897. 
Peromyscus eremicus anthonyi Mearns, Bull. No. 56, IT. S. Nat. Mus., p. 438, 

Apr. 13, 1907. 

Type locality. — Camp Apache, Big Hachita. Mountains, Grant 
County, N. Mex. 

Geographic distribution. — Extreme southeastern Arizona and 
southwestern New Mexico in the vicinity of the Mexican boundary 
line and south through the State of Sonora west of the Sierra Madre 
to northern Sinaloa. 

General characters. — Very similar to P. eremicus, but darker and 
more richly colored, but not so extreme in this respect as P. e. f rater- 
cuius; ears very slightly smaller; pectoral spot usually present. 

Color. — No. 22529 from Deming, X. Mex. Winter pelage 
(Dec. 2) : Ground color and broad lateral line rich ochraceous buff; 
entire upperparts heavily sprinkled with black, this not concentrated 
medially, but uniformly distributed ; head grayish drab, suffused with 
buff, particularly on cheeks; underparts creamy white, except a 
prominent ochraceous buff pectoral spot," extending from breast 
between forelegs almost to middle of belly; tail blackish above and 
paler below, but not sharply bicolor; feet creamy white, 'ankles' 
dusky. Worn pelage: As in P. eremicus, but darker and duller. 
Immature : Much darker and more decidedly blackish than in 

Skull. — As in P. eremicus. 

Measurements. — One adult male from Deming, N. Mex. : Total 
length, 197; tail vertebra?, 105; hind foot, 21. Average of 10 adults 
from Alamos, Sonora, Mexico: Total length, 194 (188-202); tail 
vertebra?, 108 (102-113) ; hind foot, 21.5 (21-22). 

Type specimen. — No. ffff, Collection of C. Hart Merriam. $ im- 
mature. Collected May 10, 1886, by A. W. Anthony. Skin and 
skull in good condition, but showing no subspecific characters on 
account of immaturity. 

Remarks. — The type locality of this subspecies, which was described 
before Mexican specimens had been collected, is unfortunately near 
the northern limit of the form, where it is beginning to merge with 
true eremicus. It reaches its greatest differentiation in southern 
Sonora, but at best is only slightly characterized by its richer and 
more blackish color, and although separated geographically, it closely 
resembles fraterculus. Skulls from different parts of its range vary 
slightly in size, but show no constant difference from those of typical 

Such a pectoral spot is very frequently but not always present. 


Specimens examined. — Total number 121, from localities as follows: 
Arizona:" Calabasas, 1; Fairbank, 1; Fort Verde, 8; San Bernar<lin< 

Ranch. 2; Tombstone, 1; Tonto Creek, 2; Tubac, 4. 
Chihuahua: Near Batopilas, 12. 
New Mexico:" Boundary line, 100 miles west of El Paso, 11; Camp 

Apache, Grant County, 5 ; Carrizalillo, 1 ; Deming, 5 ; Dog Spring, 

Grant County, 2; Florida Mountains. 1; Hachita, 4; Lat. 31° 47', 

long. 30° 15', 13: Bedrock 1 ; Silver City 1. 
Sonora: Alamos, 15: Camoa, 4: Guaymas, 2; Hermosillo, 17; Magdalena, 

2 ; Oposura, 2. 
Sinaloa: Culiacan, 4. 



Pcromj/sciift tiburonensis Mearns, Proc. F. S. Nat. Mus. XIX, pp. 720-721, July 
30, 1807. 

Type locality. — Tiburon Island, off coast of Sonora, Mexico. 

Geographic distribution. — Tiburon Island and immediately adja- 
cent mainland. 

General characters. — Decidedly smaller than P. e. anthonyi,' skull 
slightly different ; otherwise similar. 

Color. — Darker than P. eremicus, about as in P. e. anthonyi. Type 
specimen with pure white underparts and no pectoral spot. 

/Skull. — Similar to that of P. eremicus, but smaller; rostrum more 
depressed; braincase relatively deeper; teeth and audital bulla? small, 
about in proportion to size of skull. 

Measurements. — Dry skin of type: Total length, 170; tail verte- 
bra 3 , 92 ; hind foot, 18 ; ear from notch, 15. 

Type specimen. — No. 63186, U. S. National Museum. $ adult. 
Dec. 25, 1895. J. W. Mitchell. The skin of the type is a renovated 
specimen in fair condition. The tail vertebrae have not been removed 
and a small patch of 'hair is gone from the left side. The skull is 
perfect, except for one slightly broken zygoma. 

Remarks. — Small size seems to be the only important character 
distinguishing this form from P. e. anthonyi The tail of the type 
has the appearance of being more hairy than in most specimens from 
the mainland, but this may be due to its being a midwinter specimen, 
added to the fact that the skin of the tail is somewhat shriveled 
around the vertebra? instead of being smoothly stretched over a wire. 
Specimens from the mainland of Mexico on the Coastal Plain are 
indistinguishable from the type of tiburonensis. One, from Ortiz, 
though about the same size as tiburonensis, has a small pectoral spot 
as in anthonyi. 

Specimens examined. — Total number 4, from localities in Mexico 
as follows : 

Sonora: Batamotal, 2; Ortiz, 1; Tiburon Island, 1. 

"Among these many approach eremicus. 



Peromy8cus eremicus phwurus Osgood, Proc. Biol. Soc. Wash., XVII, pp. 75-70, 
Mar. 21, 1904. 

Type locality. — Hacienda la Paracla, San Luis Potosi, Mexico. 

Geographic distribution. — Middle part of the Mexican tableland 
in the States of San Luis Potosi, Zacatecas, and Nuevo Leon. 

General character*. — Similar to P. eremicus, but darker, with tail 
uniform blackish brown above and below instead of decidedly bicolor, 
as in eremicus, or indistinctly bicolor, as in some specimens of P. e. 

Color. — Similar in general to eremicus, but shades of buff deeper 
and entire upperparts much more heavily mixed with black; under- 
pays, except tail, white; pectoral spot not present; tail blackish 
brown above and below, this most evident in winter pelage, when 
the hairiness of the tail is best developed; feet white, ' ankles ' dusky. 

Skull. — Practically as in eremicus and anthonyi 

Measurements. — Average of 9 adults: Total length, 189 (176- 
195); tail vertebrae, 98 (92-103); hind foot, 21; ear from notch 
(dry), 16 (15.2-16.8). 

Type specimen. — No. 50438 U. S. National Museum, Biological 
Survey Collection. ? adult. Aug. 20, 1892. E. W. Nelson and 
PI A. Goldman. Specimen in good condition. 

Remarks. — This form is the southernmost representative of the 
eremicus group. Its range is practically continuous with that of 
eremicus, which extends from west Texas down through Chihuahua, 
but it is cut off by mountain ranges from anthonyi, which, curiously, 
it most closely resembles. The extreme form of anthonyi from 
southern Sonora occasionally has the distal third of the tail black 
all around, and thus very much resembles phceurus. This is probably 
an accidental parallelism, as shown also by some specimens of frater- 
culus which are strikingly like anthonyi, although there is even 
greater isolation in this case. 

Specimens c.r<//nined.—Tot&\ number 2S, from localities as follows: 

Coahuila: Sabinas, 3; Saltillo, 2. 

Nuevo Leon: Doctor Arroyo, 5. 

San Luis Potosi: Ahualnlco, 2; Hacienda La Parada, 7: Jesus Maria, 7. 

Zacatecas: Cauitas, 2. 

Prronu/scitx goldmani Osgood, Proc. Biol. So<\. Wash.. XVII, ]». 75, Mar. 21, 1904. 

Type locality. — Alamos, Sonora, Mexico. 

Geographic distribution. — Known only from the type locality. 

Characters. — Similar in general to P. eremicus anthonyi; size 
larger (hind foot 24 in type) ; pelage somewhat coarser; color more 
fulvous and more uniform; heel slightly hairy; tail long and cylin- 

252 • NOKTH AMERICAN FAUNA. [no. 28. 

drical, covered with short hairs; skull relatively heavy and rather 

Color. — Entire upperparts and sides ochraceous buff, finely mixed 
with black, much darker and richer than in anthonyi, and without 
the grayish cast usually so characteristic of the eremicus group; 
underparts creamy white, with a small ochraceous bnff pectoral spot. 

Skull. — Larger, longer, and narrower than in eremicus or anthonyi; 
braincase relatively much narrower: nasals longer and more com- 
pressed posteriorly; interorbital constriction narrow; bony palate 
rather short. 

Measurement*. — Type: Total length, 217; tail vertebra, 117; hind 
foot, 24: ear, from notch (dry), IN. 2. 

Type sped men. — No. 1)0340 U. S. National Museum, Biological 
Survey Collection. $ adult. Dec. 19, 1898. E. A. Goldman. Speci- 
men in good condition. 

Remarks. — In color and size this species resembles P. spidlegus 
closely, and. without examination of its skull and teeth, its affinity 
to the eremicus group would scarcely be suspected. 

Specimens examined. — Total number 2, both from the type locality. 

Subgenus BAIOMYS True. 

Baiomys True. Proc. U. S. Nat. Mns., XVI, p. T. r )S, Feb. 7, 1804. 

Type. — Hesperomys {Vesper! mas) taylori Thomas (=Peromyseus 
taylori) . 

Characters. — Size very small, hind foot usually less than 17; tail 
decidedly shorter than head and body; ears relatively small and 
slightly more rounded than in subgenus Peromyscus ; soles of hind 
feet almost or quite naked ; plantar tubercles ; coronoid process of 
mandible large, broad, and strongly recurved; anterior palatine 
foramina long and usually ending posterior to the plane of the front 
of the first molars; posterior palatine foramina about opposite middle 
of m 2 ; interorbital space relatively wide, usually more than half as 
wide as widest part of frontals; upper incisors relatively heavy; 
accessory cusps of m 1 and m 2 very small and not obvious in transverse 
view until a late stage of wear; inner reentrant angle of m 3 relatively 
small and usually obliterated at an early stage of wear. 

Species. — P. taylori and P. musculus. 

Remarks. — The members of this group are always recognizable by 
their small size. However, the discrepancy between them and the 
smallest forms (pallescens and polionotus) of the subgenus Pero- 
myscus is very slight. The most decided character of Baiomys 
appears in the coronoid process of the mandible, which is nearly or 
quite as well developed as in Onychomys. but this too is rather vari- 
able in Peromyscus. The skull is characterized by slight peculi- 


arities, none of which seem of more than specific value. The denti- 
tion is nearly as in typical Peromyscus, the deviation from the normal 
type being no greater than in various specific groups. The plantar 
tubercles number <'», as in Peromyscus, but they appear to be less 
variable in shape (see PL VIII, fig. 7). 

Key to species of Subgenus Baiomys. 

Size smaller: hind foot 13—15; greatesl lengtb of skull usually less than 2<». 

P. taylori. I p. 253) 
Size larger; hind foot 15—17; greatesl lengtb of skull usually 20 or more, 

P. muaculua i p. 257) 

Key to subspecies of Peromyscus taylori. 

Habitat Texas and northeastern Mexico. 

Color more grayish /'. taylori 

Color more sooty 'P. t. subater 

Habitat western and central Mexico. 

Color paler, general effect broccoli brown or fawn /'. I. paulus 

Color darker, chiefly sooty or very dark brown. - - P. /. analogu8 

Pig.. 12. — Distribution of the subgenus Baiomys. 


(PI. IV, fig. 10; pi. VIII, fig. 7.) 

Hesperomys {Vespervmus) taylori Thomas, Ann. & Mag. Nat. Hist., ser. 5, 

XIX, p. 66, Jan., 1887. 
Peromyscus {Baiomys) taylori Allen. Bull. Am. Mus. Nat. Hist., N. Y., VIII, 

p. 65, Apr. 22. 1896. 
Baiomys taylori Mearns, Bull. No. 56, D. S. Nat. Mus., p. 381, Apr. 13, 1907. 


Type locality. — San Diego, Tex. 

Geographic distribution. — Southern Texas from the vicinity of 
Matagorda Bay westward to Bexar County and thence south to the 
Rio Grande; south into Nuevo Leon and thence to southern Tamauli- 
pas. Lower Sonoran zone. 

Characters. — Size small (hind foot 13-15) ; tail much shorter than 
head and body; general color more grayish than in allied forms; 
skull smaller and lighter than in P. museulus. 

Color.-— Unworn pelage: Upperparts pale drab or ecru drab rather 
heavily mixed with dusky, producing a general effect of hair brown 
on the back and broccoli brown on the sides; head and face about 
like sides; no orbital ring, spot at base of whiskers, nor obvious 
lateral line; underparts smoke gray washed with cream buff: feet 
smoke gray; tarsal joints slightly dusky: ears thinly clothed with 
grayish hairs, producing same general effect as main body color; 
fail rather indistinctly bicolor, dull dusky above, smoke gray below. 
Worn pelage: More brownish than unworn pelage; general effect 
of upperparts grayish isabella color or wood brown slightly darker 
in middle of back. 

Skull. — Size very small, decidedly smaller than that of P. museu- 
lus; dorsal outline evenly arched; nasals short and broad, slightly 
exceeded by ascending branches of premaxillse ; interorbital space 
broad and rather sharp-angled; palatine slits long and nearly 
parallel-sided; audital bullae moderate. (For general characters, see 
subgeneric diagnosis.) 

Measurements. — Average of 7 adults from Browmsville, Tex. : Total 
length, 97 (87-110) ; tail vertebrae, 38 (34-45) ; hind foot, 14.3 
(13.4-15); ear from notch (dry), 9 (8.8-10). Of 5 adults from 
Camargo, Tamaulipas: 110 (104-118); 44 (40-50); 14.7 (14.5-15). 

Type specimen. — No. British Museum. 

Remarks. — This is the smallest species of the genus Peromyseus 
and one of the smallest of all rodents. It differs from museulus, 
the only other species of the subgenus, chiefly in its smaller size. Its 
subspecies are but slightly characterized, being in most respects, 
save shade of color, like the typical form. Although as yet there are 
gaps of considerable extent between the known ranges of the sub- 
species, the forms are so closely allied that there is little doubt of 
complete intergradation. 

Specimens examined. — Total number 102, from localities as fol- 

Nuevo Leon: Monterey, 1; Santa Catarina, 1. 

Tamaulipas: Alta Mira, 2; Camargo, 5; Hidalgo, 7: Matamoras. 5; Vic- 
toria, 0. 

Texas: Beeville, 1; Boerne, 3; Brownsville. 31; Matagorda, 4; Matagorda 
Peninsula, 7 ; Rockport 1 ; San Antonio, 2G ; San Diego, 2. 



Peromyscus taylori subater Bailey, N. Aru. Fauna No. 25, pp. 102-103, Oct. 
24. 1905. 

Type locality. — Bernard Creek, near Columbia, Brazoria County, 

Geographic distribution. — Coast region of southeastern Texas 
from the vicinity of Matagorda Bay eastward. Austroriparian 

Characters. — Similar to P. taylori, but darker and more sooty. 

Color. — Unworn pelage: General effect of upperparts dark gray- 
ish brown or sepia, sometimes almost black in middle of back; sides 
usually showing more or less buffy; underparts cream buff to clay 
color, becoming slightly paler and more grayish on throat and chin; 
tail rather more distinctly bicolor than in P. taylori. "Worn pelage: 
General effect of upperparts pale reddish sepia, slightly darker in 
middle of back. 

Skull. — As in P. taylori. 

Measurements. — Average of 7 topotypes: Total length, 99 (88— 
104) ; tail vertebra-, 39 (36-44) ; hind foot, 14.5 (14-15) ; ear from 
notch (dry), 9 (8-9.4). 

Type specimen.— No. ffflf U. S. National Museum, Biological 
Survey Collection. 9 adolescent. Feb. 25, 1892. W. Lloyd. Speci- 
men in good condition. 

Remarks. — This is a slight form differing from true taylori in 
its more sooty coloration. Intergradation with taylori apparently 
occurs in the vicinity of Matagorda Bay. The most extreme example 
(the type) is in unworn pelage and exceedingly dark, the middorsal 
region being almost black, but specimens in worn coat approach 
taylori more closely. The average difference in color, however, is 
considerable. At Richmond, Tex., Mr. Bailey (1. c.) found these 
mice " fairly common under the rich carpet of grass on the open 
prairie. Their tiny runways, leading from one little burrow to an- 
other, wound about over the surface of the ground among the plant 
stems and indicated habits so similar to those of Microtus that at 
first I thought I had discovered traces of a diminutive species of that 

Specimens examined. — Total number 15, from localities as follows: 

Texas: Austin Bayou, near Alvin, 2; Bernard Creek, near Columbia, 7; 
Richmond, 4 ; Sour Lake, 1 : Virginia Point, 1. 


Peromyscus paulus Allen, Bull. Am. Mus. Nat. Hist., XIX, pp. 598-599, Nov. 

14, 1903. 
Peromysvus allex Osgood, Proc. Biol. Soc. Wash., XVII, pp. 7(3-77, .Mar. 21, 

1904. — Colima, Colima. Mexico. 


Type locality. — Rio Sestin, northwestern Durango, Mexico. 

Geographic distribution. — Lower Sonoran and Arid Tropical parts 
of western Mexico, from central Chihuahua south and west through 
Durango, Sinaloa, and Jalisco to Colima. 

( 'haracters. — Size, proportions, and cranial characters about as in 
P. taylori; color averaging more brownish and more strongly tinged 
with fawn. 

Color.-r- Similar in general to that of P. taylori but averaging less 
grayish. Unworn pelage : General effect of upperparts broccoli 
brown tinged with fawn color. Worn pelage: General effect of 
upperparts brownish fawn color or almost clear fawn color. 

Skull. — Not definitely distinguishable from that of P. taylori; 
nasals possibly averaging slightly shorter. 

Measurements. — Type: Total length, 108; tail vertebra?, 44; hind 
foot (dry), 14. Two adults from Durango, Durango: Total length 
110, 110; tail vertebrae, 49, 43; hind foot, 15, 14; ear from notch 
(dry), 9.6, 9.8. 

Type specimen. — No. 21165 American Museum of Natural History. 
New York. $ adult. April 15, 1903. J. H. Batty. Specimen in 
fair condition. 

Remarks. — It is surprising that this form differs so slightly from 
P. taylori The only distinguishing character is the fairly constant 
tendency toward pinkish fawn color. Specimens from Colima rep- 
resenting ' ailed' ' show very little of this fawn color, but differ so 
slightly that they seem scarcely worthy of recognition. The cranial 
characters vary slightly, and chiefly in size, specimens from Colima 
being quite the smallest examined. In color there is scarcely any 
difference from musculus, which, however, is decidedly larger. 

Specimens examined. — Total number TO, from localities as follows: 

Chihuahua: Balleza, 1 ; Casas Grandes, 1. 

Colima: Colima, 10. 

Durango: Durango, 3: Rancho Santuario, 2; Rio Sestin, 15; Rosario, 1; 

San Gabriel, 2. 
Jalisco: Atemajac, 12; Etzatlan, 6. 
Sinaloa: Mazatlan, 5; Rosario, 8. 
Tepic: Acaponeta, 4. 


Type from Zamora, Michoacan. No. 120261 U. S. National Museum, Biological 
Survey Collection. $ adult. Jan. 15, 1903. E. W. Nelson and E. A. 

Geographic distribution. — West central Mexico, from Jalisco and 
Michoacan eastward to the Valley of Mexico. 

Characters. — Size, proportions, and cranial characters about as in 
taylori and paulus; color decidedly darker; feet and toes usually 
more or less dusky. 


Color. — Much as in nigrescens and subater, decidedly darker than 
in paulus, musculus, etc. Unworn pelage : General effect of sides, 
sepia ; of back, blackish sepia ; underparts slaty gray, heavily washed 
with wood brown ; fore and hind feet and toes entirely dusky brown- 
ish or slightly mixed with grayish. Worn pelage : Upperparts vary- 
ing from brownish sepia to raw umber, darkest in middle of back. 

Skull. — Essentially as in /'. t. paulus. 

Measurements. — Type: Total length, 110; tail vertebrae, 48; hind 
foot, 14; ear from notch (dry), 9.9. Average of eight topotypes: 112 
(105-123); 45.7 (39-53); 14.4 (13.5-15); 9.9 (9.6-10.3). 

Remarks. — This form is very similar in color to subater and 
nigrescens. All three have doubtless developed dark hues from ap- 
proximately the same cause, since all inhabit more humid regions 
than their paler relatives. P. t. analogus averages slightly larger 
than paulus and taylori, but the difference is not of great importance, 
as size is quite variable throughout the group. Specimens from Patz- 
cuaro and Acambaro, Michoacan, and also from Mascota and Tepic 
apparently tend toward paulus. The dusky feet of this form are 
found in the majority, but not in all specimens. 

Specimens examined. — Total number 83, from localities, as follows : 

Jalisco: Araeca, 10; Mascota, 6; Ocotlau, 8. 

Mexico: Tlalpam, 25. 

Michoacan: Acambaro, 3: Los Reyes, 8; Patzcuaro, 4; Zaniora, 10. 

Tepic: Tepic, 9. 

Key to subspecies of Peromyscus musculus. 

Color paler, general effect broccoli brown or wood brown. Western and southern Mexico, 

P. musculus 

Color darker, chiefly rich dark brown or sooty. 

Color more brownish. State of Veracruz , P. m. brunneu.8 

Color more blackish. Chiapas and Guatemala '_P. m. nigrescens 

(PL IV, fig. 11; pi. V, fig. 10; pi. VI, fig. 10; pi. VII, fig. 11.) 

Sitomys musculus Merriam. Proc. Biol. Soc. Wash., VII, pp. 170-171, Sept. 29, 

Peromyscus musculus Allen and Chapman, Bull. Am. Mus. Nat. Hist., N. Y., 

IX, p. 203, June 10, 1897. 
Baiomys musculus Mearns, Bull. No. 50, 1'. S. Nat. Mus., p. 381, Apr. 13, 1907. 

Type locality. — Colima, Colima, Mexico. 

Geographic distribution. — Arid tropical parts of central and 
southern Mexico from the Isthmus of Tehuantepec north to central 
Veracruz and northwest to Colima and possibly to central Sinaloa. 

Characters. — Similar in color and general characters to P. taylori 
paulus, but decidedly larger (hind foot 15-17) ; skull larger and 

6626S— No. 28—09 17 


Color. — Practically as in P. t. paulus, averaging slightly less fawn. 
Unworn pelage: Ground color of upperparts clay color heavily 
mixed with dusky, producing a general effect varying from dark 
broccoli brown to isabella color, scarcely or not at all darker in mid- 
dle of back; underparts dull cream buff, sometimes becoming grayish 
white on throat; feet white or grayish white, tarsal joint slightly 
dusky; tail indistinctly bicolor, brownish above, grayish white below. 
"Worn pelage : Upperparts nearly uniform cinnamon, lightly sprin- 
kled with dusky or sometimes paler, almost clay color. 

Skull. — Decidedly larger than in P. taylori and subspecies; brain- 
case actually and relatively broader; nasals usually not exceeded by 
ascending branches of premaxilla?; molars larger and heavier. 

Measurements. — Average of 10 adult topotypes : Total length, 124.7 
(116-135) ; tail vertebras, 50.8 (42-56) ; hind foot, 16.5 (16-17) ; ear 
from notch (dry), 11.2 (10.5-12). 

Type sped men. — No. flffj U. S. National Museum, Biological 
Survey Collection. $ adult. March 9, 1892. E. W. Nelson. Speci- 
men in good condition. 

Remarks. — The distinction between this species and P. taylori is 
chiefly one of size. Representatives of the two species are found to- 
gether at least at one locality, Colima, and there they are distinct 
with no suggestion of interbreeding. At other localities, so far as 
known, only one species occurs, though each species varies in size so 
it is sometimes difficult to decide whether one is dealing with small 
examples of musculus or with large ones of the taylori series. The 
subspecies of musculus, like those of taylori, are chiefly characterized 
by color alone, apparently controlled by the relative humidity of their 
respective habitats. Specimens from Culiacan, Sinaloa, and Val- 
paraiso, Zacatecas, are tentatively referred to musculus, though their 
skulls are somewhat peculiar. 

Specimens examined. — Total number 204, from localities as fol- 

Colima: Armeria, 8; Colima, 10. 

Guerrero: Aeapnleo, 3; AyuSinapa, 1: Chilpancihgo, 14; El Limon, 3; 

near Ometepec, 7; Rio Balsas, 1 : Tlalixtaquilla, 3: Tlapa, 1. 
Jalisco: Plantinar, 1: Zapotlan, 3. 
Michoacan: La Huacana, 1; La Salada, 11. 
Morelos: Cnernavaca, 9: Pnente de Ixtla. 2; Yauteper, 12. 
Oaxaca: Chicapa, 2; Huilotepec, 12; Juquila. 8; Llano Grande, 3: Oaxaca. 

15: Pinotepa, 2; Reforma, S: San Bartolo, 1 : Tenuantepec, 26; near 

Totolapa, 1 : Yaganiza, 1; Yalalag, 1. 
Puebla: Acatlan, 1; Piaxtla, 4. 
Sinaloa: Culiacan, 2. 

Veracruz: Carrizal. 4: Chichicaxtle, 4; Santa .Maria, 9. 
Zacatecas: Valparaiso, 10. 



Peromyseus musculus brunneus Allen and Chapman. Bull. Am. Mus. Nat. Hist., 
N. Y., IX. pp. 208-204, June 16, 1S97. 

Type locality. — Jala pa, Veracruz, Mexico. 

Geographic distribution. — East central Mexico, in slightly more 
humid parts than those inhabited by P. musculus. 

Characters. — Similar to P. ■musculus, but darker and more richly 
colored ; very slightly smaller. 

Color. — Similar in general to that of P. musculus, but darker and 
more brownish; general effect of upperparts varying from reddish 
sepia to raw umber and Prout brown; underparts dull clay color 
slightly mixed with grayish and slaty ; feet whitish gray ; tail very 
indistinctly bicolor, brownish above, soiled whitish gray below. 

Skull. — Similar to that of P. musculus, but averaging slightly 
smaller; nasals somewhat shorter. 

Measurements. — Average of 20 topotypes: Total length, 118 (110- 
130); tail vertebrae, 46.8 (10-51); hind foot, 15.3 (14.5-16.5): ear 
from notch (dry), 10.7 (10.4-11.2). 

Type specimen. — No. iffff American Museum of Natural History, 
New York. ? adult, April 13, 1897. F. M. Chapman. Skin in 
good condition ; skull with small puncture in supraoccipital and 
unimportant breaks in zygoma and basioccipital. 

Remarks. — This form is characterized chiefly by its rich brownish 
color. Tt inhabits slightly more humid places than typical m usculus. 
which lives near it in comparatively arid conditions. Doubtless its 
range will prove to be rather more extensive than at present known. 
It is somewhat intermediate between musculus and nigrescens, but 
appears never to be as sooty as nigrescans and also differs slightly in 
cranial characters. 

Specimens examined. — Total number 42, from localities as follows : 
Veracruz: Jalapa, 39; Texolo, 3. 


Peromyseus musculus nigrescens Osgood, Proc. Biol. Soe. Wash., XVII, i>. Ti'., 
March 21, 11)04. 

Type locality. — Valley of Comitan, Chiapas, Mexico. 

Geographic distribution. — Southern Mexico (State of Chiapas) 
and northern Guatemala. 

Characters. — Similar to P. musculus and P. m. brunneus, but- 
darker and more sooty ; skull slightly characterized. 

Color. — Upperparts mixed Vandyke brown and sooty, the sooty 
slightly concentrated in middle of back; underparts cream buff, to 
roots of hairs in middle of belly, on tips only at sides; feet usually 



I no. 28. 

dull whitish gray, sometimes slightly brownish dusky; tail indis- 
tinctly bicolor, dusky above, grayish white mixed with brownish 

Skull. — Slightly smaller and more elongated than in P. musculus 
and P. m. brunneus; braincase narrower; interorbital space narrower. 

Measurements. — Average of ten adult topotypes: Total length, 
115.5 (113-120) ; tail vertebrae, 43 (40-45) ; hind foot, 15 (14.5-16) ; 
ear from notch (dry), 11 (9.8-12). 

Type specimen. — No. 76827 U. S. National Museum, Biological 
Survey Collection. ? adult. Dec. 0, 1895. E. W. Nelson and E. A. 
Goldman. Specimen in good condition. 

Remarks. — In the m/usculus series this form is analogous to the 
dark forms of the taylori series. It differs slightly in cranial char- 
acters from P. m. brunneus, but is only a few degrees darker in 
color. Its range is apparently cut off from that of brunneus by the 
arid Isthmus of Tehuantepec, inhabited by typical museulus. 

Specimens . examined. — Total number 53, from localities as fol- 
lows : 

Chiapas: Ocozucuautla, 2; Ocuilapa, 4; San Bartolome, 2; Sau Vicente, 
1 ; Tonala, 8 : Tuxtla Gutierrez, 4 ; Valley of Comitan, 22 ; Valley 
of Jiquipilas, 1. 
Guatemala: Jacaltenaugo, 8; Nenton, 1. 

Table of external measurements of Peromyscus. 
External measurements — averages and extremes. 


Total length. 

Tail ve 



Hind foot. 

Ear, from notch 










P. maniculatus 























75- 95 
82- 97 
82- 93 
78- 90 
93- 98 
62- 78 









22. 5 



20. 5 



20. 5 








20. 7 


19 -23 
20. 8-21. 8 

20 -22 
20 -22 

P. m. gracilis 


16. 7-18. 3 


P. m. abietorum 


P. m. argentatus 



15 -16 
15. 2-16 
15 -16.8 
15. 9-17. 1 
14. 5-16. 8 
15 -16.4 

14 -15.2 

15 -17 


P. m. nubiterrae 

19. 5-21 
19 -21 
22 -24 
22 -23.5 
22 -23.5 


P. m. arcticus 

P. m. oreas 


















P. m. hylaeus 

P. m. algidus 


P. m. kceni 


P. m. macrorhinus. . . 

P. m. artemisiae 

P. m. saturatus 


69- 86 





P. m. hollisteri 

P. m. austerus 

P. m. rubidus 

P. m. gambeli 


73- 84 
79- 96 
70- 77 
56- 75 
56- 71 
56- 65 
70- 54 
50- 52 
59- 75 
65- 78 

64- 82 

65- 80 
79- 86 

74- 81 
68- 78 
77- 92 
























14 -15.5 
15. 2-16. 9 
14. 2-15. 8 
14. 1-16. 6 
14 -15.7 



-20. 5 



P. m. nebrascensis 


P. m. bairdi 

15. 4-18 
14. 6-17. 5 

14 -17 

15 -16.8 
14. 6-17. 4 

P. m. palleseens 

P. m. blandu's 




P. m. labecula 

P. m. sonoriensis 

P. m. coolidgei 

P. m. margaritae 

P. m. dementis 

P. m. catalinae 

P. m. dubius 













External measurements — averages and extremes — Continued. 


P. m. geronimensis . . 

P. m. cineritius 

P. m. magdalenae. . . 

P. sitkensis ;. . 

P. s. prevostensis 

P. polionotus 

P. p. niveiventris 

P. p. phasma 

P. p. rhoadsi 

P. melanotis 

P. leucopus 

P. 1. noveboracensis . 

P. 1. ammodytes 

P. 1. fusus 

P. 1. aridulus 

P. 1. ochracens 

P. 1. tornillo 

P. 1. arizonae 

P. I. texanus 

P. 1. mesomelas 

P. 1. castaneus 

P. 1. afflnis 

P. 1. cozumelae 

P. gossypinus 

P. g. megacephalus. . 

P. g. palmarius 

P. g. anastasae 

P. boylei 

P. b. iowleyi 

P. b. attwateri 

P. b. spicilegus 

P. b. simulus 

P. b. madrensis 

P. b. evides 

P. b. levipes 

P. b. azteeus 

P. oaxacensis 

P. hylocetes 

P. pectoralis 

P.p. eremicoides 

P. p. laceianus 

P- truei 

P. t. gilberti 

P. t. martirensis 

P. t. lagunae 

P. t. gratus 

P. t. gentilis 

P. nasutus 

P. polius 

P. difBcilis 

P. d. amplus 

P. d. felipensis 

P. bullatus 

P. melanophrys 

P. m. zamorae 

P. m. consobrinus. . . 

P. xenurus 

P. mekisturus 

P. lepturus 

P. lophurus 

P. simulatus 

P. guatemalensis 

P. furvus 

P. nudipes 

P. mexicanus 

P. m. totontepecus. . 

P. m. saxatilis 

P. m. teapensis 

P. m. gymnotis 

P. allophylus 

P. banderanus 

P. b. vicinior 

P. b. angelensis 

P. yucatanicus 

P. y. badius 

P. altilaneus 

P. raegalops 

Total length. 




































































Tail vertebrae. 

Aver- Ex- 
age, tremes. 






































79- 85 
75- 78 
82- 96 





50- 60 

58- 66 
73- 80 
73- 83 
71- 88 
85- 96 
63- 73 
82- 82 
75- 97 
78- 85 

68- 79 
81- 84 
76- 90 
72- 71 
78- 90 







Hind foot. 



22. 4 
































24. 5 





































21 -23 
22' "-2§" 

25 -28 
17 -19 

20 -21.5 

20 -21 

21 -22 
19. 5-21 
21. 5-23. 5 
21 -23 
22. 5-22. 5 



20. 5-22. 8 

20 -22 

22 -24 

22 -24 
24 -23 

23 -26 
20 -22 

21 -23 

21 -23 

23 -25 

23 -25 







25 -27 

20 -22 

20 -21 

22 -23 

22 -24 

Ear, from notch 







-24. 5 





25. 5-28 



25. 5-27. 5 



26. 5-28 























26. 5-28 












































21. 5 























14. 4-16. 4 
12 -13.4 
11. 6-13. 5 

17 -19.2 
13. 4-14 


14. 1-15. 6 

13. 7-15. 7 
15 -16.8 
15 -16.3 
14 -15 

15. 3-17. 5 
16. 6-18 
15. 5-17. 2 
15. 4-17. 3 

12. 6-14. 5 
15. 6-16. 7 

14. 5-16 
15. 8-17. 5 
17. 5-18. 5 

15. 4-17. 2 
14. 3-16. 6 
15 -16.2 
21. 5-24 
18 -21 
21 -23 
18 -19.8 
17. 5-20. 2 

18 -19.3 
18. 5-20. 5 
17. 2-18. 5 
19. 7-23 
19. 5-21.8 

19 -21.7 

18. 5-21 
19 -21 
18 -19. 

16. 4-18. 2 

20 -21.5 
20 -23 
18. 4-19. 4 
17. 7-20. 5 

16 -17.8 
16. 6-19. 5 

17 -18.6 
15 -17 

17. 2-18. 5 

16 -16.5 

17 -17.7 
15. 2-18. 3 
16 -16.8 




1-j.rtcriKii measurements — averages <i>ni extremes — Continued. 


Total length. 

Tail vi 


Hind foot. 

Ear, from notch 

















isi. 2 





































14 5 

14 4 


















14 5 













P. m. melanurus 

P. melanocarpus 

P. zarhynchus 



26 -28.5 





80- 93 
80- 88 
80- 95 

32 -34 
35 -32 
31 -33 
19 -20 
17 -20 
26 -27.5 
26 -29 

21. 2-24 














20 -24 
14 4-16. 4 
13. 4-14 6 
22 -25 
21. 3-23. 5 
20 -20.7 
15. 5-17 
15. 5-16. 5 

15. 6-17. 2 

16. 5-16. 7 
13. 4-16 
14 6-16. 8 



P. n. aureolus 


P. californicus 



P. eremicus 

20 -21 





20 -21 

20 -19.5 
21. 5-22 
19 -20 

21 -22 



P. e. avius 













P. e. polypolius . 

P. e. anthonyi 


P. e. phaeurus 



15. 2-16. 8 




92- 97 
89- 98 
34- 45 
36- 44 
43- 49 

39- 53 
42- 56 

40- 51 
40- 45 

15. 4-17. 5 
16. 6-18 
15. 3-16. 5 
9. 6- 9. 8 
9. 6-10. 3 
10. 5-12 


P. c. auripectus 

P c. stephensi 

20 -21 


14 5-15 
14 -15 
14 -15 
13. 5-15 
16 -17 
14 5-16. 5 
14 5-16 




P. t. analogus 

P. musculus 

P. m. brunneus 

P. m. nigrescens 






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[About one and one-third times natural size] 

Fig. 1. Peromyscus maniculatus (Wagner). Labrador. (No. 3666 Mus. Comp. 
Zool., Cambridge, Mass.) 

2. Peromyscus maniculatus arcticus (Mearns). Topotype. Fort Simpson, 

Mackenzie, Canada. Adult male. (No. 133957 U. S. Nat. Mus., 
Biological Survey Coll.) 

3. Peromyscus maniculatus austerus (Baird). Topotype. Steilacoom, 

Wash. Adult male. (No. 42935 U. S. Nat. Mus.. Biological Survey 

4. Peromyscus maniculatus hylaeus Osgood. Type. Hollis, Prince of 

Wales Island, Alaska. Adult male. (No. 127038 I T . S. Nat. Mus., 
Biological Survey Coll.) 

5. Peromyscus maniculatus uracil is (Le Conte). Mountain View, N. Y. 

Adult female. (No. 93635 U. S. Nat. Mus., Biological Survey Coll.) 

6. Peromyscus maniculatus hollisteri Osgood. Type. Friday Harbor, San 

Juan Island, Washington. Adult male. (No. 130316 U. S. Nat. Mus., 
Biological Survey Coll.) 

7. Peromyscus sitkensis Merriam. Topotype. Sitka, Alaska. Adult male. 

(No. 73816 U. S. Nat. Mus., Biological Survey Coll.) 

8. Peromyscus maniculatus keeni (Rhoads). Cumshewa Inlet, Moresby 

Island, Queen Charlotte Islands, British Columbia. Adult female. 
(No. 100726 U. S. Nat. Mus., Biological Survey Coll.) 
!». Peromyscus maniculatus pallescens Allen. Topotype. San Antonio. 
Tex. Adult male. (No. 87876 U. S. Nat. Mus.. Biological Survey 
* Pi. Peromyscus maniculatus bairdi (Hoy and Kennicott). Onaga, Kan. 
Adult female. (No. 33851 U. S. Nat. Mus., Biological Survey Coll.) 

11. Peromyscus polionotus (Wagner). Gainesville, Fla. Adult female. 

(No. 4659 Coll. of C. Hart Merriam.) 

12. Peromyscus maniculatus gambeli (Baird). Topotype. Monterey, Calif. 

Adult female. (No. 447S0 U. S. Nat. Mus., Biological Survey Coll.) 


North American Fauna No. 28, U. S. Dept. Agr. Biological Survey. 

Plate II. 

1. P. manieulatus. 

2. P. m. arcticus. 

3. P. ru. austerus. 

4. P. m. hylaeus. 

Skulls of Peromyscus. 

5. P. m. gracilis. 

6. P. m. hollisteri. 

7. P. sitkensis. 

8. P. m. keeni. 

9. P. m. pallescens. 

10. P. m. bairdi. 

11. P. polionotus. 

12. P. in. gambeli. 


[About one and one-third times natural size.] 

Fig. 1. Peromyscus leucopus tornillo Mearns. Juarez. Chihuahua, Mexico. 
Adult male. (No. 58368 U. S. Nat. Mus., Biological Survey Coll.) 

2. Peromyscus gossypinus (Le Coute). Riceboro, Ga. Adult male. (No. 

45081 U. S. Nat. Mus., Biological Survey Coll.) 

3. Peromyscus leucopus cozumelte Merriam. Topotype. Cozuinel Island, 

off Yucatan, Mexico. Adult female. (No. 108440 U. S. Nat. Mus.. 
Biological Survey Coll.) 

4. Peromyscus leucopus mesomelas Osgood. Topotype. Orizaba. Vera- 

cruz, Mexico. (No. 58208 U. S. Nat. Mus., Biological Survey Coll.) 

5. Peromyscus oaxacensis Merriam. Topotype. Cerro Sau Felipe, Oaxaca. 

Mexico. Adult female. (No. 68598 U. S. Nat. Mus., Biological Sur- 
vey Coll.) 

6. Peromyscus lophurus Osgood. Type. Todos Santos, Guatemala. Adult 

male. (No. 77210 U. S. Nat. Mus., Biological Survey Coll.) 

7. Peromyscus simulatus Osgood. Type. Jico, Veracruz, Mexico. Adult 

female. (No. 55028 U. S. Nat. Mus., Biological Survey Coll.) 

8. Peromyscus hylocetes Merriam. Topotype. Patzcuaro, Michoacan. 

Mexico. Adult male. (No. 50421 U. S. Nat. Mus., Biological Survey 
P. Peromyscus crinitus (Merriam). Topotype. Shoshone Falls, Idaho. 
Adult female. (No. 31656 IT. S. Nat. Mus., Biological Survey Coll.) 

10. Peromyscus crinitus stephensi Mearns. Panamint Mountains, California. 

Adult male. (No. 40788 U. S. Nat. Mus., Biological Survey Coll.) 

11. Peromyscus eremicus (Baird). Hardy River, Lower California, Mexico. 

Adult male. (No. 81868 U. S. Nat. Mus., Biological Survey Coll.) 

12. Peromyscus leucopus texanus (Woodhouse). Brownsville, Tex. Adult 

male. (No. 41753 U. S. Nat. Mus., Biological Survey Coll.) 

North American Fauna No. 28, U. S. Dept. Agr. Biological Survey. 

Plate III 

1. P. 1. tornillo. 

2. P. gossypinus. 

3. P. 1. cozumelse. 

4. P. 1. mesomelas. 

Skulls of Peromyscus. 

5. P. oaxacensis. 

6. P. lophurus. 

7. P. simulatus. 
S. P. hylocetes. 

9. P. crinitns. 

10. P. c. stephensi. 

11. P. eremicus. 

12. P. 1. texanus. 


[About one and one-third times natural size.] 

Fig. 1. Peromyscus boylei (Baird). Topotype. Middle Fork American River, 
California. Adult male. (No. 43232 U. 8. Nat. Mus., Biological Sur- 
vey Coll.) 

2. Peromyscus boylei levipes Merriam. Type. Mount Malinche, Tlaxcala, 

Mexico. Adult male. (No. 53673 U. S. Nat. Mus., Biological Survey 

3. Peromyscus boylei spicilegus Allen. Topotype. San Sebastian, Jalisco, 

Mexico. Adult female. (No. 58543 U. S. Nat. Mus., Biological Survey 

4. Peromyscus boylei simulus Osgood. Type. San Bias, Tepic, Mexico. 

Adult male. ( No. 88088 U. S. Nat. Mus., Biological Survey Coll.) 

5. Peromyscus boylei astecus (Saussure). Topotype. Mirador, Veracruz, 

Mexico. Adult female. (No. 58543 U. S. Nat. Mus., Biological Survey 

6. Peromyscus truei (Shufeldt). Topotype. Fort Wingate, N. Mex. Adult 

female. (No. 46789 IT. S. Nat. Mus., Biological Survey Coll.) 

7. Peromyscus pectoralis eremicoides Osgood. Type. Mapimi, Durango, 

Mexico. Adult male. (No. 57729 U. S. Nat. Mus., Biological Survey 

s. Peromyscus nasutus (Allen). Cold Hill, Colo. Adult female. (No. 

(>;i2<;4 U. S. Nat. Mus., Biological Survey Coll.) 
9. Peromyscus truei gratus Merriam. Topotype. Tlalpam, D. F., Mexico. 

Adult male. (No. 50613 U. S. Nat. Mus., Biological Survey Coll.) 

10. Peromyscus taylori (Thomas). Brownsville, Tex. Adult female. (No. 

48813 U. S. Nat. Mus., Biological Survey Coll.) 

11. Peromyscus musculus Merriam. Topotype. Armeria, Colima, Mexico. 

Adult female. (No. 45441 II. S. Nat. Mus., Biological Survey Coll.) 

12. Peromyscus lepturus Merriam. Topotype. Mount Zempoaltepec. Oaxaca, 

Mexico. Adult male. (No. 68615 U. S. Nat. Mus., Biological Survey 


North American Fauna No. 28, U. S. Dept. Agr. Biological Survey. 

Plate IV. 

1. P. boylei. 

2. P. b. levipes. 

3. P. b. spiciiegus. 

4. P. b. siruulus. 

Skulls of Peromyscus. 

5. P. b. aztecus. 

6. P. truei. 

7. P. p. eremicoides. 

8. P. nasiuus. 

9. P. t. gratus. 

10. P. taylori. 

11. P. musculus. 

12. P. lepturus. 

66268— No. 28—09 18 


[About one and one-third times natural size.] 

Fig. 1. Peromyscus banderanus Allen. Hacienda Magdalena, Coliina, Mexico. 
Adult male. (No. 45330 F. S. Nat. Mus.. Biological Survey Coll.) 

2. Peromyscus guatemalensis Merriam. Topotype. Todos Santos, Guate- 

mala. (No. 76852 U. S. Xat. Mus.. Biological Survey Coll.) 

3. Peromyscus melanophrys (Cones). Yaganiza. Oaxaca. Mexico. Adult 

male. (No. 68606 F. S. Nat. Mus.. Biological Survey Coll.) 

4. Peromyscus yucatanicus Allen and Chapman. Fa Vega, Yucatan. 

Mexico. Adult female. (No. 108424 F. S. Nat. Mus.. Biological Sur- 
vey Coll.) 

5. Peromyscus megalops Merriam. Mountains near Chilpancingo, Guerrero, 

Mexico. Adult male. (No. 70188 F. S. Nat. Mus.. Biological Survey 

6. Peromyscus difflcilis (Allen). Topotype. Valparaiso Mountains. Za- 

catecas. Mexico. Adult female. (No. 01829 F. S. Nat. Mus., Biologi- 
cal Survey Coll.) 

7. Peromyscus furvus Allen and Chapman. Jico, Veracruz. Mexico. 

Adult female. (No. 55021 F. S. Xat. Mus., Biological Survey Coll.) 

8. Peromyscus mexicanus (Saussure). Topotype. Mirador. Veracruz. 

Mexico. Adult male. (No. 58547 F. S. Nat. Mus., Biological Survey 

9. Peromyscus {Peromyscus) leucopus noveboracensis (Fischer). Montauk 

Point. New York. Adult male. (No. 56714 F. S. Nat. Mus.. Biologi- 
cal Survey Coll.) 

10. Peromyscus (Baiomys) musculus (Merriam). Armeria, Colima, Mexico. 

Adult female. (No. 45441 F. S. Nat. Mus.. Biological Survey Coll.) 

11. Peromyscus (Ochrotomys) nuttalli (Harlan). Dismal Swamp. Virginia. 

Adult male. (No. 7510S V. S. Nat. Mus.. Biological Survey Coll.) 

12. Peromyscus (Haplomylomys) eremicus (Baird). Hardy River, Lower 

California, Mexico. Adult male. (No. 81868 F. S. Nat. Mus., Biologi- 
cal Survey Coll.) 

13. Peromyscus (Megadontomys) thomasi Merriam. Topotype. Mountains 

near Chilpancingo. Guerrero, Mexico. Adult female. (No. 70413 F. S. 
Nat. Mus., Biological Survey Coll.) 

14. Peromyscus (Podomys) fforidanus (Chapman). Cape Canaveral. Flor- 

ida. Adult female. (No. 2341C. F. S. Nat. Mus., Biological Survey 


North American Fauna No. 28, U. S. Dept. Agr. Biological Survey. 

Plate V. 

1. P. banderanus. 

2. P. guatemalensis. 

3. P. melanophrys. 

4. P. yucatanicus. 

5. P. megalops. 

Skulls of Peromyscus. 

6. P. difficilis. 

7. P. furvus. 

8. P. mexicanus, 

9. P, 1. noveboracensis. 
10. P. musculus. 

11. P. nuttalli. 

12. P. eremicus. 

13. P. thomasi. 

14. P. floridanus. 


[About one and one-third times natural size.] 

Fig. 1. Peromyscus {Peromyscus) zarhynchus Merriain. Topotype. San Cris- 
tobal, Chiapas, Mexico. Adult male. (No. 76097 U. S. Nat. Mus., 
Biological Survey Coll.) 

2.2 a. Peromyscus (Megadontomys) flavidus Bangs. Topotype. Boquete, Chir- 

iqui, Panama. (No. 10331 Mus. Comp. Zool., Cambridge, Mass.) 

3.3 a. Peromyscus (Megadontomys) thomasi Merriam. Topotypes. Moun- 

tains near Chilpancingo, Guerrero, Mexico. (3. No. 70144; 3a. No. 
70143 U. S. Nat. Mus., Biological Survey Coll.) 
4. Peromyscus (Peromyscus) leucopus (Raflnesque). Houma, La. Adult 
female. (No. 46011 U. S. Nat. Mus., Biological Survey Coll.) 

5. 5 a. Peromyscus (Hanlomylomys) californicus (Gambel.) Topotype. Mon- 

terey, Calif. Adult male. (No. 44777 U. S. Nat. Mus., Biological Sur- 
vey Coll.) 

6. 6 a. Peromyscus (Podomys) floridanus (Chapman). Cape Canaveral, 

Florida. Adult female. (No. 23416 U. S. Nat. Mus., Biological Sur- 
vey Coll.) 

7,7a. Peromyscus (Ochrotomys) nuttalli (Harlan). Dismal Swamp, Vir- 
ginia. Adult female. (No. 95886 U. S. Nat. Mus., Biological Survey 

8, 8 a. Peromyscus (Peromyscus) Icucoyus noveboracensis (Fischer). Jaw. 
8. East Hartford, Connecticut. Adult male. (No. 64349 U. S. Nat. 
Mus., Biological Survey Coll.) 8a. Montauk Point, New York. 
Adult male. (No. 56714 U. S. Nat Mus., Biological Survey Coil.) 
9. Peromyscus (Haplomylomys) eremicus (Baird). Jaw. Hardy River, 
Lower California, Mexico. Adult male. (No. 81868 U. S. Nat. Mus., 
Biological Survey Coll.) 
10. Peromyscus (Baiomys) musculus (Merriam). Jaw. Armeria, Colima, 
Mexico. Adult female. (No. 45441 U. S. Nat. Mus., Biological Sur- 
vey Coll.) 


North American Fauna No. 28, U. S. Dept Agr. Biological Survey. 

Plate VI. 

1. P. zjirhvnchus. 

2, 2a. P. fl'avidus. 

3, 3a. P. thomasi. 

4. P. leucopus. 

Skulls and Jaws of Peromyscus. 

6, 5a. P. californicus. 

6, 6a. P. floridaims. 

7, 7a. P. nuttalli. 

8, 8a. P. 1. noveboracensis 

9. P. eremk'us. 
10. P. musculus. 


[About one and one-third times natural size.] 

Fig. 1. Peromyscus floridanus (Chapman). Cape Canaveral, Florida. Adult 
female. (No. 23416 U. S. Nat. Mus., Biological Survey Coll.) 

2. Peromyscus nuttalli (Harlan). Dismal Swamp, Virginia. Adult male. 

(No. 75198 U. S. Nat. Mus., Biological Survey Coll.) 

3. Peromyscus leucopus noveboracensis (Fischer). East Hartford, Conn. 

Adult male. (No. 64349 U. S. Nat. Mus., Biological Survey Coll.) 

4. Peromyscus crcmicus (Baird). Hardy River, Lower California, Mexico. 

Adult male. (No. 81868 U. S. Nat. Mus., Biological Survey Coll.) 

5. Peromyscus thomasi Merriam. Topotype. Mountains near Chilpan- 

cingo, Guerrero, Mexico. Adult male. (No. 70144 U. S. Nat. Mus., 
Biological Survey Coll.) 

6. Peromyscus mexicanus (Saussure). Topotype. Mirador, Veracruz, 

Mexico. Adult male. (No. 5S547 II. S. Nat. Mus., Biological Survey 

7. Peromyscus bullatus Osgood. Type. Perote, Veracruz, Mexico. Adult 

female. (No. 54405 IT. S. Nat. Mus., Biological Survey Coll.) 

8. Peromyscus flavidus Bangs. Topotype. Boquete, Chiriqui, Panama. 

(No. 10331 Mus. Comp. Zool., Cambridge, Mass.) 

9. Peromyscus boylei (Baird). Topotype. Middle Fork American River, 

California. Adult male. (No. 43232 U. S. Nat. Mus., Biological Sur- 
vey Coll.) 

10. Peromyscus truei (ShufelAt). Topotype. Fort Wingate, N. Mex. Adult 

female. (No. 46789 U. S. Nat. Mus., Biological Survey Coll.) 

11. Peromyscus musculus (Merriam). Armeria, Colima, Mexico. Adult 

female. (No. 45441 U. S. Nat. Mus., Biological Survey Coll.) 

12. Peromyscus maniculatus gracilis (Le Conte). Mountain View, N. Y. 

Adult female. (No. 93635 U. S. Nat. Mus., Biological Survey Coll.) 


North American Fauna No. 28, U. S. Dept. Agr. Biological Survey. 

Plate VII. 

1. P. floridanus. 

2. P. nuttalli. 

3. P. 1. noveboracensis. 

4. P. eremicus. 

Skulls of Peromyscus. 

5. P. thomasi. 

6. P. mexicanus. 

7. P. bullatus. 

8. P. flavidus. 

9. P. bovlei. 

10. P. truei. 

11. P. musculus. 

12. P. m. gracilis. 


[Teeth about seven and one-half times natural size; soles about two and one-half times.] 

Figs. 1, la, lb, lc. Peromyscus (Megadontomys) thomasi Merriam. 

1. Side view of upper molars. (No. 126887 U. S. Nat. Mus., 

Biological Survey Coll.) 
la. Worn crowns of upper molars. (No. 126SS9 I T . S. Nat. 

Mus., Biological Survey Coll.) 
lb. Worn crowns of lower molars. (No. 126889 U. S. Nat. 

Mus., Biological Survey Coll.) 
lc. Sole of bind foot. (No. 126889 tl. S. Nat. Mus., Biological 

Survey Coll.) 

2. 2a, 2b, 2c. Peromyscus (Peromyscus) leucopus uoreboracensis (Fiscber). 

2. Side view of upper molars. (No. 449.39 U. S. Nat. Mus.. 

Biological Survey Coll.) 
2a. Worn crowns of upper molars. (No. 96930 U. S. Nat. Mus., 

Biological Survey Coll.) 
2b. Worn crowns of lower molars. (No. 96929 U. S. Nat. Mus., 

Biological Survey Coll.) 
2c. Sole of hind foot. (No. 82924 U. S. Nat. Mus., Biological 

Survey Coll.) 

3. Peromyscus eremicus (Baird). Side view of upper molars. (No. S1870 

U. S. Nat. Mus., Biological Survey Coll.) • 

4. Peromyscus {Haplomylomys) califomicus Gambel. Crowns of upper 

molars. (No. 97134 U. S. Nat. Mus., Biological Survey Coll.) 
5,5a. Peromyscus (Ochrotomys) nuttaUl (Harlan). 

5. Worn crowns of upper molars. ( No. 75198 U. S. Nat. Mus., 

Biological Survey Coll.) 
5a. Sole of bind foot. (No. 140805 IT. S. Nat. Mus., Biological 
Survey Coll.) 

6. Peromyscus (Peromyscus) maniculatus gracilis (Le Conte). Sole of 

bind foot. (No. 147327 U. S. Nat. Mus., Biological Survey Coll.) 

7. Peromyscus [Baiomys) taylori (Thomas). Solo of bind foot. (No. 

18287 U. S. Nat. Mus.) 

8. Peromyscus (Podomys) floridanus Chapman. Sole (if hind foot. (No. 

111458 C. S. Nat. Mus.) 


North American Fauna No. 28, U. S. Dept. Agr. Biological Survey. 

Plate VIII. 

F. von Itersen, del. 

Molar Teeth and Soles of Peromyscus. 

1, la, lb, lc. P. thomasi. 

2, 2a, 26, - 2r\ P. 1. noveboracensis. 

3. P. eremicus. 

4. P. ciUii'ornieus. 

5, 5a. P. nuttalli. 
fp. P. m. gracilis. 

7. P. taylori. 

8. P. floridanus. 


[New names in black face type; synonyms in italics.] 

abietorum, Peromyscus, 45. 
affinis, Hesperomys, 133. 
Peromyscus, 133. 
Vesperimus, 133. 
akeleyi, Peromyscus, 63. 
albifrons, Peromyscus, 108. 
nlK'idiiN, reromyscus, 50. 
allew, Peromyscus, 255. 
allophylus, Peromyscus, 206. 
altilaneus, Peromyscus, 197. 
amrrieanus, Mus, 117. 

Sitomys, 117. 
Vesperimus, 113, 117. 
ammodytes, Peromyscus, 121. 
amplus, Peromyscus, 181. 
analogas, Peromyscus, 256. 
anastasae, Peromyscus, 141. 
angelensis, Peromyscus, 210. 
anthoiiyi, Hespcromys, 240. 
Peromyscus, 240. 
Vesperimus, 249. 
arbor eus, Peromyscus, 117. 
arcticus, Hespcromys, 40, 49. 

Peromyscus, 49. 
arenarius, Peromyscus, 104. 239. 
argentatus, Peromyscus, 46. 
aridnliis, Peromyscus, 122. 
arizonae, Peromyscus, 126. 

Sitomys, 126. 
Arvicola emmonsi, 117. 

nuttalM, 224. 
auritus, Peromyscus, 214. 
artemisiae, Peromyscus, 58. 

Sitomys, 5S. 
attwateri, Peromyscus, 147. 
uureolus, Calomys, 225. 
Mus, 225. 
Peromyscus, 225. 
auripectus, Peromyscus, 231. 

Sitomys, 231. 

austerus, Hespcromys, 63. 

Peromyscus, 63. 

aviuM, Peromyscus, 247. 


badius, Peromyscus, 212. 
Baiomys, 32, 252. 
Baiomys musculus, 257. 
taylori, 253. 

bairdii, Mus, 79. 

Peromyscus, 79. 
baliolus, Peromyscus, 104. 
banderanus, Peromyscus, 207. 
beatae, Peromyscus, 153. 
bellus, Peromyscus, 147. 
blandus, Peromyscus, 84. 
boylii, Hesperomys, 142. 
boyiei, Peromyscus, 142. 
brunneus, Peromyscus, 259. 
bullatus, Peromyscus, 183, 


cacabaius, Peromyscus-, 195. 
cdlifornicus, Mus, 234. 

Peromyscus, 234. 
Calomys aureolus, 225. 
campestris, Hesperomys, 117. 
canadensis, Sitomys, 42. 
callus, Peromyscus, 127. 
carolinensis, Mus, 135. 
castaneus, Peromyscus, 133. 
catalinae, Peromyscus, 97. 
cecilii, Peromyscus, 109. 
cedrosensis, Peromyscus, 244. 
cherrii, Hesperomys, 75. 
Vesperimus, 75. 
cineritius, Peromyscus, 100. 
dementis, Peromyscus, 96. 
eounatus, Hesperomys, 136. 
Color descriptions, 21-22. 
comptus, Peromyscus, 214. 
consobrinus, Peromyscus, 188. 
coolidgei, Peromyscus, 94. 
cozumelae, Peromyscus, 135. 
Cricetus myoides, 117. 
triii it us, Hespcromys, 229. 
Peromyscus, 229. 
criatobalensis, Peromyscus, 217. 


deserticolus, Hespcromys, 89. 
difflcilis, Peromyscus, 178. 
Vesperimus, 178. 
dubius, Peromyscus, 98. 
dyselius, Peromyscus, 169. 

Economic status, babits and, 26-28. 
emmonsi, Arvicola, 117. 




[NO. 28. 

eremicoides, PeromyscuB, 163. 
eremicus, Hesperomys, 239. 
Peromyscus, 239. 
«■!•«• nni>. Peromyscus. 47. 
eva, Peromyscus. 245. 
evides, Peromyscus, 152. 
i xiguus, Peromyscus, 99. 


felipensis, Peromyscus, 182. 
flaccidus, /'( romyscus, 125. 
flavidu8, Megadontomys, 221. 

Peromyscus, 221. 
floridanus, Hesperomys, 227. 
Peromyscus, 227. 
fraterculus, Peromyscus, 24:*. 
Sitomys, 24:-!. 
Vtsjiei imus, 24:?. 
fulvus, Peromyscus, 86. 
furvus, Peromyscus, 196. 
f usus, Peromyscus. 1 22. 


gadovii, Peromyscus, 185. 
gambeli, Hesperomys, 67. 

Peromyscus, 67. 

Sitomys, 67. 
gaurus, Peromyscus, 145. 
gentilis, Peromyscus, 175. 
Genus Peromyscus. characters, 33. 
geronimensis, Peromyscus, 99. 
gilberti, Peromyscus, 169. 

Sitomys, 169. 
goldmani, Peromyscus, 251. 
gossipinus, Hypudaeus, 135. 
gossypinus, Hesperomys, 135. 
Peromyscus, 135. 
gracilis, Hesperomys, 42. 

Peromyscus, 42. 
gratus, Peromyscus. 17::. 
jjuatemalensis, Peromyscus, 193. 
gymnotis, Peromyscus, 205. 


Habits and economic status, 26-28. 
Haplomylomys. :;.'!. 228. 
hemfonotis, Peromyscus, 171. 
herroni, Sitvmys, 243. 
Hesperomys, 32. 
Hesperomys tiffin is, 133. 

anthonyi, 249. 

arcticus, 40, 49. 

austerus, 62. 

aztecus, 156. 

boylii, 142. 

campestris, 117. 

cheirii, 75. 

cognatus, 136. 

ci in it us, 2i".». 

deserticoJus, 89. 

fremitus, 239. 

florithiuiis, 227. 

gambeli, 07. 

gossi/pinus, 135. 

Hesperomys gracilis, 42. 

leucopus, 1 1 •'!. 
macropus, 227. 

milllitltltit its, 40. 

megaloti8, 165. 
melanopJirys, L84. 
mexicanue, 198. 

nebrascensis, 75. 77. 

niveiven I ris, 105. 

nudipes, 195. 

nuttalU, 224. 

parasiticus, 2::4. 

in fin its, 72. 

sonoriensis, 89. 

taylori, 25.".. 

texa ntt. 127. 
History and nomenclature. 11-14. 
holliateri, Peromyscus, 02. 
homochroia, Peromyscus, 24:;. 
liylaeus, Peromyscus, 5:!. 
uylocetes, Peromyscus, 159. 
Hypudaeus gossipinus, 135. 


insignis, Peromyscus. 237. 
insolatus, Sitomys, 89. 
insulanus, Peromyscus, 141. 
insnlicola, Peromyscus, 246. 
Intergradation, 17-19. 


Keys, 23. 

keeni, Peromyscus, 55. 
Sitomys, 55. 


labecula, Peromyscus, 87. 
laceianus, Peromyscus. 104. 
laceyi, Peromyscus, 148. 
lagunae, Peromyscus, 172. 
Itisius, Peromyscus, 165. 
lepturus, 1'eromyscus, 190. 
leucopus, Hesperomys, 113. 

.i/1/.s, ii a 

Mustiiliis, 1 1 •"!. 

Peromyscus. 113. 

Vesperimus, 113. 
leucuius, Peromyscus, 185. 
levipes, Peromyscus. L53. 
lophurus, Peromyscus, 192. 
luteus, Peromyscus. 77. 


macropus, Hesperomys, 227. 
macrorhinus. Peromyscus, 57. 

x Hi) in lis, 57. 
ruadrensis. Peromyscus, 152. 
magdalenar, Peromyscus, 101. 
major, Sitomys, 145 
maniculatus, Hesperomys, 40. 

Peromyscus. 40. 
liiargaritae, Peromyscus, 95. 
martirensis. Peromyscus. 171. 
Sitomiis, 171. 




Material, 10-11. 
mearnsii, Vesperimus, 127. 
Measurements, 22-23. 

table of cranial, 26:?. 
table of external, 260. 
medius, Peromyscus, 67. ■ 
megacephalus, Peromyscus, 138. 

Sitomys, 138. 
Megadontomys, 33, 218. 
Megadontomys da v id us, 221. 
nelsoni, 221. 
thomasi, 219. 
megalops, Peromyscus. 213. 
megalotis, Hesperomys, 165. 
mekisturus, Peromyscus, 189. 
melanocarpus. Peromyscus. 216. 
melanotis, Peromyscus. 100. 
melanophrys, Hesperomys, 184. 
Peromyscus, 184. 
melanurus, Peromyscus, 215. 
merriami, Peromyscus, 239. 
mesomelas, Peromyscus, 132. 
metallicola, Peromyscus, 145. 
mexicanus, Peromyscus, 198. 
Hesperomys, 198. 
michiganensis, Hits, 117. 

Peromyscus, 79. 
minnesotae, Peromyscus, 117. 
mississippiensis, Peromyscus, 138. 
montipinoris, Peromyscus, 166. 
Mus americanus, 117. 
aureolus, 225. 
bairdii, 79. 
californicus, 234. 
carolinensis, 135. 
leucopus, 113. 
michiganensis, 117. 
noveboraccnsis, 117. 
polionotus, 104. 
musculoides, Peromyscus, 133. 
Musculus leucopus, 113. 
musculus, Baiomys, 257. 

Peromyscus, 257. 
Sitomys, 257. 
myoides, Cricetus, 117. 


nasutus, Peromyscus, 176. 

Vesperimus, 176. 
ncbrascensis, Hesperomys, 75, 77. 
Peromyscus, 75, 77. 
nelsoni, Megadontomys, 221. 

Peromyscus, 221. 
New subspecies, 32. 
nicaraguae, Peromyscus, 203. 
nigellus, Sitomys, 243. 
nigrescens, Peromyscus, 259. 
Nomenclature, history and, 11—14. 
noveboraccnsis, Mus, 117. 

Peromyscus, 117. 
nubiterrae, Peromyscus, 47. 
nudipes, Hesperomys, 195. 

Peromyscus, 195. 

Vesperimus, 195. 
nuttalli, Arvicola, 224. 

Hesperomys, 224. 

Peromyscus, 224, 


oaxacensis, Peromyscus. 158. 
ochracens, Peromyscus, 124. 
Oehrotomys, .*!.",, 222. 
oreas, Peromyscus, 51. 
oresterus, Peromyscus, 89. 
orizabae, Peromyscus, 202. 


pallescens, Peromyscus, 83. 
palmarius, Peromyscus, 139. 
parasiticus, Hesperomys, 234. 
Peromyscus, 145. 
paulus, Peromyscus, 255. 
pavidus, Peromyscus, 17.'!. 
pectoralis, Peromyscus, 160. 
Pelases, 19-21. 
penicillatus, Peromyscus, 145. 
perimekurus, Peromyscus, 65. 
Peromyscus, genus, 32-33. 

subgenus, 33-34. 
Peromyscus abietorum, 45-46. 

akeleyi, 63. 

afflnis, 133-134. 

albifrons, 108-109. 

:■ livid us. 56. 

allex, 255. 
allophylus, 206-207. 
altilaneus, 197-198. 
ammodytes, 121-122. 
amplus, 181-182. 
analogous, 256—257. 
anastasae, 141. 
angelensis, 210. 
anthonyi, 249-250. 
arboreus, 117. 
arcticus, 49-51. 
arenarius, 104, 239. 
argentatus, 46. 
iiriiliiliiN, 122. 
arizonae, 126—127. 
artemisiae, 58-61. 
attwateri, 147-149. 
aureolus, 225—226. 
auripectus, 231-232. 
auritus, 214-215. 
austerus, 63-65. 
avius, 247—248. 
aztecus, 156-158. 
badius, 212. 
bairdi, 79-83. 
baliolus, 104. 
banderanus, 207-209. 
beatae, 153. 
bellus, 147. 
blandus, 84. 
boylei, 142. 
brunneus, 259. 
bullatus, 183-184. 
cacabatus, 195. 
californicus, 234-237. 
can us, 127 
castaneus, 133. 
catalinae, 97. 
cecilii, 109. 
cedrosensis, 244—245. 
cineritius, 100. 



[no. 28. 

Peromyscus dementis, 90. 
comptus, 214. 
coolidgei, 94. 
consobrinus, 188. 
cozumelae, 135. 
crinitus, 229-231. 
Cristobal 'crisis, 217. 
difflcilis, 178-181. 
dubius, 98. 
dyselius, 169. 
eremicoides, 163-164. 
eremicus, 239-242. 
eremus, 47. 
eva, 245-24(1. 
evides, 152. 
exiguits. 99. 
felipensis, 182-183. 
flaccidus, 125. 
flavidus, 221-222. 
floridanus, 227—228. 
fraterculus, 24.">-244. 
fulvus, 86. 
furvus, 196. 
fusus, 122. 
gadovii, 185. 
gambeli, 67. 
gaums, 145. 
gentilis, 175. 
geronimensis, 99. 
gllberti, 169-171. 
goldmani, 251. 
gossypinus, 135-138. 
gracilis, 42-45. 
gratus, 173-174. 
guatemalensis, 193-195. 
gymnotis, 2()5-20(>. 
hemionotis, 171. 
holliateri, 02. 
homochroia, 243. 
hylaeus, 53. 
hylocetes, 159-160. 
insignis, 237-238. 
insula nits, 141. 
insnllcola, 246-247. 
keeni, 55. 
labecula, 87. 
laceianus, 104-l(;.~p. 
laceyi, 148. 
lag ii nae, 172. 
la8W8, 165. 
lepturus, 190-192. 
leucopus, 113-117. 
leucurus, 185. 
levipes, 153-155. 
lophurus, 192. 
luteus, 77-79. 
macrorhinus, 57. 
inadrensis, 152. 
uiagrda lenae, 101. 
maniculatus, 40—12. 
iiiiti'u'iiril.'ii'. 95. 
martiivnsis, 171-172. 
medius, 67. 

megacephalus, 138-139. 
megalops, 213-214. 
mekisturus, 189. 
melanocarpus, 216-217. 

Peromyscus welanophrys, 184-180. 
melanotis, 109-112. 
iiii-I:i n ii i-iin, 215—216. 
merriami, 239. 
mesomelas, 132. 
metulUcola, 145. 
mexieanus, 198-201. 
michigatiensis, 79. 
minnesotae, 117. 
mississippiensis, 138. 
montipinoris, 166. 
mu8culoides, 133. 
musculus, 257-258. 
nasutus, 176-177. 
nebrascensis, 75-77. 
nelsoni, 221. 
niearaguae, 203. 
nigrescens, 259-260. 
niveiventris, 105. 
noveboracensis, 117-121. 
nubiterrae, 47. 
nudipes, 195-196. 
nuttalli, 224-225. 
oaxacensis, 158-159. 
oehraceus, 124—120. ) 
oreas, 51-53. 
orizabae, 202. 
oresterus, 89. 
pallescens, 83-84. 
paliuarius, 139-140. 
parasiticus, 145. 
paulus, 255-256. 
par id us, 173. 
pectoralis, 160-162. 
penicillatus, 145. 
perimekurus, 65. 
petraius, 232. 
phaeui'us, 251. 
phasma, 107. 
polionotus, 104-105. 
polius, 177-178. 
l»ol j imiI i us, 248. 
prevostensis, 102. 
propinquus, 245. 
rhoadsi, 107-108. 
rowleyi. 145-147. 
rubidus, 65-67. 
ruflnus, 72-74. 
sagaw, 173. 
saturatus, 61. 
saxatilis, 203-204. 
scitulus, 229. 
simulatus, 193. 
simulus, 151. 
sitkensis, 101-102. 
sonoriensis, 89. 
spicilegus, 149-151. 
stephensi, 232-234. 
subarcticus, 58. 
subater, 255. 
subgriseus, 104. 
taylori, 253-2.">4. 
teapensis, 204. 
tehuantepccus, 199. 
texanus, 127-131. 
thomasi, 219-220. 
tiburonensis, 250. 




Peromyscus tornillo, 125-126. 

totontepecus, 202—203. 

truei, 165-169. 

umbrinus, 40. 

vicinior, 209. 

xenurus, 188-189. 

yucatanicus, 211. 

eamelas, 109. 

zamorae. 187. 

zarhynchus, 217-218. 

zelotes, 173. 
petraius, Peromyscus, 232. 
phaeurus, Peromyscus, 251. 
phasma, Peromyscus, 107. 
p in a 1 is , 8 i to >n ys , 145. 
Podoiuys, 33, 226. 
polionotus, Mas, 104. 

Peromyscus, 104. 
polius, Peromyscus, 177. 
polypolius, Peromyscus, 248. 
prevostensis, Peromyscus. 102. 
propinquus, Peromyscus, 245. 


Records of specimens, 23-24. 
rhoadsi, Peromyscus, 107. 
robust us, Sitomys, 142. 
rowleyi, Peromyscus, 145. 

Sitomys, 145. 
rubidus, Peromyscus, 65. 
rufinus, Hesperomys, 72. 

Peromyscus, 72. 


sagax, Peromyscus, 173. 
saturatus, Peromyscus, 61. 
saxatilis, Peromyscus, 203. 
scitulus, Peromyscus, 229. 
simulatus, Peromyscus. 193. 
simulus. Peromyscus. 151. 
sitkensis, Peromyscus, 101. 
Sitomys, 32. 
Sitomys americanus, 117. 

arizonae, 126. 

artemisiae, 58. 

auripectus, 231. 

canadensis, 42. 

fraterculus, 243. 

gambelU, 67. 

gilberti, 169. 

herroni, 243. 

insolatus, 89. 

keeni, 55. 

major, 145. 

martirensis, 171. 

megacephalus, 138. 

nigellus, 243. 

maerorhinus, 57. 

musculus, 257. 

pinalis, 145. 

robustus, 142. 

rowleyi, 145. 

subgriseus, 104. 

thurberi, 67. 
sonoriensis, Hesperomys, 89. 
Peromyscus, 89. 

Species and subspecies, list of, 28-31. 
spicilegus, Peromyscus, 149. 
stephensi, Peromyscus, 232. 
subarcticus, Peromyscus, 58. 
sulmrer, Peromyscus, 255. 
Subgenera, 24-26. 
Subgenera, key to. .".2. 
Subgenus Baiomys, 252. 

Haplomylomys, 228. 

Megadontomys, 218. 

Ochrotomys, 222. 

Peromyscus, 33. 

Podomys, 226. 
subgriseus, Peromyscus, KM. 
Sitomys, 104. 

taylori, Baiomys, 253. 

Hesperomys, 253. 

Peromyscus, 253. 

Vesperimus, 253. 
teapensis, Peromyscus, 204. 
tchuantepecus, Peromyscus, 199. 
tcxana, Hesperomys, 127. 
texanus, Peromyscus, 127. 
thomasi, Megadontomys, 219. 

Peromyscus, 219. 
thurberi, Sitomys, 67. 
tiburonensis, Peromyscus, 250. 
tornillo, Peromyscus, 125. 
totontepecus, Peromyscus, 202. 
Trinodontomys, 33. 
truei, Hesperomys, 165. 
Peromyscus, 165. 
Type localities, list of, 28-31. 


umbrinus, Peromyscus, 40. 


Variation, 14 16. 
Vesperimus, '■'<-. 
Vesperimus aflinix, 133. 

americanus, 1 13, 117. 

anthonyi, 249. 

cher r ii, 75. 

difflcilis, 178. 

fraterculus, 243. 

leucopus, 113. 

mearnsii, 127. 

n as ut us, 176. 

nudipes, 195. 

taylori, 253. 
vicinior, Peromyscus, 209. 


xenurus, Peromyscus, 188. 


yucatanicus, Peromyscus, 211. 

zamelas, Peromyscus, 109. 
zamorae, Peromyscus, 187. 
zarhynchus, Peromyscus, 217. 
zelotes, Peromyscus, 173. 





No. 2 9 

[Actual date of publication, August 31, 1909] 




Prepared under the direction of 




I- E-9 




N"o. 29 

[Actual date of publication, August 31, 1909] 




Prepared under the direction of 








U. S. Department of Agriculture, 

Bureau of Biological Survey, 
Washington, D. C, April 25, 1909. 

Sir: I have the honor to transmit herewith for publication as 
North American Fauna No. 29 a revision of The Rabbits of North 
America, by E. W. Nelson, Chief Field Naturalist of the Biological 
Survey. Rabbits inhabit nearly all parts of North America, where 
they have become adapted to both mountains and lowlands, and to 
the varied physical and climatic conditions from the tropical forests 
to the arctic tundras, and from the humid marshes of the seacoast 
to the arid deserts of the interior. Many of the species are destruc- 
tive to nursery stock and other agricultural crops; as an offset, their 
flesh has considerable food value, furnishing an acceptable article of 
diet to thousands of our people. 

Heretofore there has been no treatise by means of which our Amer- 
ican rabbits could be identified; the present revision, therefore, will 
prove not only a much needed addition to zoological literature but 
also a welcome aid to all who have occasion to identify or study these 

Respectfully, C. Hart Merriam, 

Chief, Biological Survey. 

Hon. James Wilson, 

Secretary of Agriculture. 



Introduction 9 

Relations of American rabbits to agriculture 11 

Use of the names hare and rabbit 13 

Condition of the young at birth 14 

Distribution of hares and rabbits in North America 15 

Changes in distribution 20 

Habits 21 

Diseases 23 

Increase after epidemics 24 

Distribution of color 1 24 

Melanism and albinism 26 

Dichromatism 26 

Character of pelage 27 

Differences in pelage due to age 28 

Molts and other seasonable changes in pelage 29 

Species having two annual molts 29 

Species having one annual molt 31 

Sexual variation 32 

Individual variation 32 

Skull characters and variation 33 

Geographic variation 34 

Instability of characters due to geographic variation 34 

Persistence of general characters under similar climatic conditions 35 

Effect of isolation under like climatic conditions 36 

Genera and subgenera 37 

List of species of North American hares and rabbits, with type localities 47 

Key to species and subspecies 49 

Genus Lepus , 59 

Lepus arcticus group 59 

Lepus campestris group 72 

Lepus americanus group 84 

Lepus callotis group 115 

Lepus calif amicus group 126 

Genus Sylvilagus 159 

Sylvilagus floridanus group 159 

Sylvilagus nuttalli group 199 

Sylvilagus auduboni group 211 

Sylvilagus cunicularius group 238 

Sylvilagus bachmani group 245 

Sylvilagus gabbi group 257 

Sylvilagus palustris group 265 

Genus Brachylagus 275 

Genus Romerolagus 279 

Bibliography 280 





Plate I. Lepus callotis Frontispiece. 

II. Skulls (dorsal view) of Lepus virginianus 288 

III. Skins of Lepus californicus xanti and L. insularis 290 

IV. Skulls (dorsal view) of Lepus grcenlandicus, L. arcticus, and L. cam- 

pestris 292 

V. Skulls (side view) of Lepus grcenlandicus, L. arcticus, and L. cam- 

pestris 294 

VI. Skulls (dorsal and side views) of Lepus americanus, L. washingtoni, 

and L. bairdi 296 

VII. Skulls (dorsal view) of Lepus californicus, L. c. richardsoni, L. cal- 
lotis, and L. alleni 298 

VIII. Skulls (side view) of Lejms californicus, L. c. richardsoni, L. callotis, 

and L. alleni 300 

IX. Skulls (dorsal and side views) of Sylvilagus transitionalis, S. flori- 

danus, S. f. chapmani, and S. f. yucatanicus 302 

X. Skulls (dorsal and side views) of Sylvilagus f. holzneri, S. nuttalli, 

S. n. pinetis, and S. bachmani 304 

XI. Skulls (dorsal and side views) of Sylvilagus auduboni, S. a. arizonie, 

S. a. parvulus, and S. a. baileyi 306 

XII. Skulls (dorsal and side views) of Sylvilagus minensis, S. gabbi, S. pa- 

lustris, and S. insonus 308 

XIII. Skulls (dorsal, side, and ventral views) of Eomerolagus nelsoni, 

Brachylagus idahoensis, and Sylvilagus cunicularius 310 


Fig. 1. Map of American Desert Plateau region 17 

2. Distribution in North America of the genus Lepus 38 

3. (a) First to seventh ribs and dorsal vertebrae of Lepus {L. campestris, 

Nebraska, No. 49622, U. S. Nat. Mus.) 39 

(b) First to seventh ribs and dorsal vertebrae of Sylvilagus (S.f. mearnsi, 

Monroe County, New York, No. 49624, U. S. Nat. Mus. ) 39 

4. (a) Second to fifth cervical vertebra? of Lepus (L. campestris, Nebraska, 

No. 49622, U.S. Nat. Mus.) 40 

(b) Second to fifth cervical vertebrae of Sylvilagus (S.f. mearnsi, Mon- 
roe County, New York, No. 49624, U. S. Nat. Mus. ) 40 

5. (a) Radius and ulna of Lepus (L. campestris, Nebraska, No. 49622, 

U. S. Nat. Mus.) 40 

(b) Radius and ulna of Sylvilagus (S. f. mearnsi, Monroe County, New 

York, No. 49624, U.S. Nat. Mus.) 40 




Fig. 6. Distribution in North America of the genus Sylvilagus 43 

7. Distribution of Lepus arcticus, L. grccnlandicus, L. othus, L. poadromus, 

and L. campestris, and allied forms 60 

8. Distribution of Lepus americanus, L. bairdi, and L. washingtoni, and 

allied forms 85 

9. Distribution of Lepus alleni, L. gaillardi, L. callotis, L. flavigularis, and 

L. altamirse, and allied forms 116 

10. Distribution of Lepus californicus and allied forms 127 

11. Distribution of Sylvilagus floridanus and allied forms 160 

12. Distribution of Sylvilagus transitionalis 196 

13. Distribution of Sylvilagus nutlalli and allied forms 199 

14. Distribution of Sylvilagus auduboni and allied forms 212 

15. Distribution of Sylvilagus cunicidarius and allied forms 238 

16. Distribution of Sylvilagus bachmani and allied forms 246 

17. Distribution of Sylvilagus palustris, S. aquaticus, S. gabbi, and S. insonus, 

and allied forms - 258 

18. Distribution of Brachylagus idahoensis 276 

19. Distribution of Romerolagus nelsoni 279 



By E. W. Nelson. 


Hares and rabbits are generally distributed throughout most of 
the United States, and often become excessively numerous, especially 
in the West. Wherever they exist in large numbers in an agricul- 
tural section they are extremely destructive to crops, fruit trees, 
nurseries, and forest seedlings, and thus possess considerable eco- 
nomic importance. The habits of the several species vary widely, 
however, and some are comparatively harmless. The investigations 
of the Biological Survey into the relations of these mammals to 
agriculture and forestry have been hampered by the imperfect infor- 
mation available concerning the number of existing species and their 
distribution. It thus became necessary to study the group in detail. 
Several years ago Dr. C. Hart Merriam, Chief of the Biological 
Survey, did much work on the rabbits with the intention of mono- 
graphing the group, but other affairs interfered. Since then much 
new material has been collected and the group was finally placed in 
my hands for revision. Throughout this work Doctor Merriam has 
given me the benefit of his knowledge of the group in helpful criti- 
cisms and suggestions. 

The present revision includes all of the known hares and rabbits 
of North America, from the Isthmus of Panama to north Greenland. 
Although among the commonest of North American mammals, yet 
up to within comparatively few years they were represented in col- 
lections by extremely scanty and imperfect material. Owing to this, 
the ranges of only a few species were well known, and the relation- 
ships of a large number of species and their geographic races were 
little understood. In 1877 Dr. J. A. Allen published a monograph 



of the North American Leporidse covering the same area as the 
present paper. The material then available for study was so lim- 
ited that for the entire continent Doctor Allen recognized only 18 
species and ' varieties.' In the present monograph 97 species and 
subspecies are recognized, two or three of which, in the light of more 
satisfactory material, may prove unworthy of retention in the list. 

The active field work of the last twenty years has resulted in the 
accumulation in American museums of superb series of North Ameri- 
can mammals. The wealth of material in these collections is apparent 
from the fact that in the preparation of this monograph I have been 
able to examine more than 5,500 specimens, of which about 3,500 are 
skins with skulls; the others are odd skulls. Good series of speci- 
mens are now available from nearly all parts of Canada, the United 
States, Mexico, and, to a less extent, from Central America. Repre- 
sentatives of every species and subspecies recognized here have been 
examined. In some instances only a single specimen, usually the 
type, has been seen, but in the majority of cases series have been ex- 
amined. For instance, I have had the use of 170 specimens of the 
Texas jack rabbit (Z. c. texianus) and 345 specimens of the Macken- 
zie varying hare (Z. a. macfarlani) . Still, numerous gaps exist, 
sometimes including areas of considerable size, from which no speci- 
mens have been seen. The existing collections, however, cover the 
continent so completely that for the first time it is possible to deter- 
mine most of the previously unsettled questions of distribution and 
relationship. Considerable detailed field work is still necessary, how- 
ever, to secure material for the solution of many minor problems. 

The majority of the type specimens of North American hares and 
rabbits are still extant and in the possession of American museums, 
so that I have had access to them. The types of about three-fourths 
of the total number of recognized forms, and also those of various 
synonj^ms, have been examined. The types of about a dozen rab- 
bits described from North America are in European museums, mainly 
in London and Berlin. Fortunately, while I was preparing the 
present monograph, Mr. W. H. Osgood visited Europe and exam- 
ined and made notes on several important types, and thus obtained 
information which fixes the status of several names. In a limited 
number of species the names were based on descriptions with no 
type mentioned ; or the types, if named, are no longer extant ; but 
in all such cases material is available from the locality or region 
whence came the original specimens. By far the most extensive 
and complete series of specimens is that of the Biological Survey 
collection, in which 90 species and subspecies are represented. Three 
additional species are in the United States National Museum, so 

a Monograph of North American Rodentia, 1877. 


that the National collections contain 93 out of the 97 recognizable 
species and subspecies of North American rabbits. 

The abundant recent material in the National Museum, exclusive 
of that of the Biological Survey, consists largely of the fine collec- 
tions made by Dr. E. A. Mearns on the Mexican boundary and else- 
where. Many important points in regard to the ranges and rela- 
tionships of species would have remained undetermined but for 
the generous loan of material from various museums and private 
collections. It is therefore a pleasant duty to acknowledge with 
sincerest thanks the courtesy of Prof. John Macoun, Canadian Geo- 
logical Survey; Dr. J. A. Allen, American Museum of Natural 
History; Mr. Samuel Henshaw and Mr. Outram Bangs, Museum 
of Comparative Zoology; Mr. Witmer Stone, Academy of Natural 
Sciences, Philadelphia ; Dr. D. G. Elliot, Field Museum of Natural 
History; Prof. A. G. Ruthven, University of Michigan; Prof. L. L. 
Dyche, University of Kansas; Mr. H. G. Smith, State Historical 
and Natural History Society, Denver; Mr. W. E. Clyde Todd, Car- 
negie Museum, Pittsburg; Mr. M. W. *Lyon, United States National 
Museum ; Mr. E. R. Warren, Colorado Springs, Colorado ; Mr. H. P. 
Attwater, Houston, Texas, and others. In addition I wish to express 
my appreciation of the constant assistance of Mr. N. Hollister, of the 
Biological Survey, in the laborious task of handling and comparing 
the great mass of material studied in the preparation of this paper. 


From the earliest settlement of America to the present day rabbits 
of various species have been more or less important as game, and 
have formed a valuable addition to the food supply. At the same 
time both cottontails and jack rabbits have long been blacklisted 
among the notorious enemies of the farmer and fruit grower. Cot- 
tontails live in practically all sections of the United States except 
parts of the northern border, and in many places are extremely 
numerous. They are serious pests to fruit growers on account of 
their fondness for the bark of trees and the tender growths of nursery 
stock. They also destroy young grapevines and garden crops. A 
good illustration of the damage to agriculture by cottontails was 
given in the summer of 1907 on a small ranch in the San Joaquin 
Valley, California, where the valley cottontails completely destroyed 
the vines on 3^ acres along one side of a young vineyard of 33 acres, 
the loss amounting to about $500. The widespread abundance of 
cottontails and their destructiveness in nearly all parts of their range 
make it evident that the aggregate annual loss from them in the 
entire country amounts to a very large sum. In some sections their 
persistent destruction of small seedling trees interferes seriously with 


the efforts of the Forest Service to reforest mountain slopes. Cot- 
tontails are less numerous and destructive in certain areas than in 
others, and some species are practically harmless, mainly because they 
live in sections where at present there is little or no agriculture. 

Jack rabbits are much larger than cottontails, and are restricted 
to the region west of the Mississippi River. From the first arrival 
of farmers in the arid region of the West, jack rabbits have shown 
great fondness for growing crops. For this reason, even when 
present in comparatively small numbers, they cause considerable 
annual loss. They invade grainfields and often take up permanent 
residence in growing alfalfa. They destroy not only grain and 
forage crops but also vineyards, nurseries, and orchards. Jack 
rabbits sometimes become excessively abundant over large areas, 
notably in Texas, Colorado, Utah, Idaho, Oregon, and California. 
During the periods of abundance they do enormous damage to agri- 
culture and even threaten the total destruction of crops. They are 
reported to have damaged the crops of Tulare County, California, 
to the amount of $G00,000 in a single year, and one county in Idaho 
paid $30,000 in bounties on these pests in a year. In several parts 
of the West they have at times become so numerous and destructive 
that the people have organized public drives. Poundlike inclosures 
were set up, with wire fences leading to the entrances. The rabbits 
were then driven into the inclosures and killed by long lines of 
beaters. In this way as many as 20,000 jack rabbits have been killed 
in a single drive in the San Joaquin Valley, California. The experi- 
ence of Australia proves that rabbits are capable of destroying the 
agricultural welfare of great regions. 

As an offset to the damage done by rabbits it should be stated 
that they have a high food value. They are the commonest and most 
widely distributed of our game animals, and during fall and winter 
countless thousands of them are sold in markets throughout the coun- 
try. The total value of the rabbits thus sold in the United States, 
in addition to those consumed in the country, amounts to a large sum. 
It has recently been stated that about 2,000,000 varjdng hares are 
caught each winter in Maine, half of which are shipped out of the 

Rabbits are usually most numerous in the arid West but often be- 
come extremely plentiful east of the Mississippi. During the winters 
from 1870 to 1871 I repeatedly saw farmers driving large wagons 
full of cottontails through the streets of Chicago and selling them at 
absurdly low prices. During recent years the demand for them has 
increased, so that they now command ready sale at good prices. 

a The Jack Rabbits of the United States, by T. S. rainier. U. S. Biol. Survey 
Bull. No. 8, 1S96, contains photographs of rabbit drives. 


In addition to the value of rabbit flesh for food, their skins are 
extensively used. The fur forms the basis of felt for hats and the 
skin is used for making gelatine, jujube, sizing, and glue. In 1895 
one of the leading furriers of New York estimated that 1,500,000 
rabbit skins were collected annually for the trade, mainly in Mary- 
land, Virginia, and North Carolina. In addition, during the same 
year, millions of rabbit skins were imported into this country to 
supply the demand. The skins vary in value from 1 to 5 cents each. 


The terms hare and rabbit were first used to distinguish the two 
well-known European species Lepus timidus and Lepus cuniculus 
(now Oryctolagus cuniculus). The application of these terms has 
gradually broadened until they now have group significance, all 
members of the circumpolar genus Lepus belonging to the hares, while 
several genera, both of the Old World and of the New, are referable 
to the rabbits. 

The essential characters relied upon by European authors to 
distinguish the Old World hares and rabbits are that hares live in 
forms and bring forth their young already provided with a well- 
developed coat of hair and with eyes open ; while the rabbits, on the 
other hand, live in burrows and bring forth their young naked and 
with eyes closed. These writers have agreed in stating that all 
American members of the Leporidse are hares, and some of them have 
assumed and stated as a fact that their young are born in the same 
condition as those of the Old World hares. In reality this is prob- 
ably true only of the American species belonging to the genus Lepus 
as here restricted to include the jack rabbits and the varying and 
arctic hares. The facts given below prove that three species of the 
genus Sylvilagus bring forth their young naked and blind, as do the 
European rabbits, and it is fairly safe to assume that all other mem- 
bers of the genus do the same. In addition, the habits of the genera 
Brachylagus and Romerolagus make it more than probable that in 
this particular they agree with Sylvilagus. While some of the spe- 
cies of the American genus Sylvilagus commonly use forms, all make 
more or less use of burrows, usually the deserted homes of other 
mammals, or of shelters under rocks, roots of trees, and similar 
places. They often enlarge the ready-made shelter they occupy, but 
Brachylagus and Romerolagus are known to make their own bur- 
rows or tunnels, and even some of the cottontails have been known to 
make shallow burrows. 

Taking the condition of the young at birth as a criterion, it thus 
appears that the term rabbit can be properly used in a general way 
to apply to all the species which have the burrowing habit more or 


less pronounced and which bring forth blind and naked young ; while 
the term hare should be restricted to the species which practically 
always use forms instead of burrows and bear young well clothed 
with fur and with eyes open at birth. Common usage is thus correct 
in applying the term rabbit to the American cottontails and their 
small relatives of North and South America. So much for the 
technical value of common names ; but in the untechnical terminology 
of the people ' rabbit ' is of practically universal use in the United 
States, with modifying terms according to the species. ' Jack rabbit,' 
' white-tailed jack rabbit,' and 'snowshoe rabbit ' are names used 
for species which are technically hares, but attempts to change names 
in common usage for book names are worse than useless. In the case 
of the common varying and arctic hares, no good and generally 
accepted common names appear to be available. In Mexico the 
proper distinction is in common use, and the jack rabbits are called 
liebre (hare) and the cottontails conejo (rabbit). 


It is well known that the arctic hares, jack rabbits, and varying 
hares bring forth their young £ully clothed with hair and with their 
eyes open, but I have been unable to find any satisfactory published 
information on the condition of young cottontails at birth. Fortu- 
nately, however, it has been possible to gather sufficient evidence to 
make it practically certain that young cottontails are born naked and 

In a letter dated February 27, 1906, Mr. Howard Lacey, of Kerr- 
ville, Texas, says : " I have read somewhere that the cottontail brings 
forth its young like the jack rabbit and our hare at home [England], 
with the eyes open and a good coat of fur on them. I have often 
found them here blind and naked, like our old-country rabbits." The 
cottontail referred to by Mr. Lacey is Sylvilagus floridanus chapma?ii. 

A recent letter from Mr. J. D. Mitchell, Victoria, Texas, adds 
further information concerning the condition of the newly born 
young of this subspecies, as follows: " In 1861 to 1862, my brother 
and myself used the four walls of an old concrete gin house on our 
plantation in Lavaca County, Texas, as a rabbit pen. In this we kept 
from 20 to 30 adult rabbits. In those two years I believe I witnessed 
every phase in the domestic life of the cottontails. * * * I have 
watched the mother rabbit build her nest — have handled the young 
before they were dry. * * * I am sure that the young come into 
the world naked, blind, and helpless. The skin was usually dark 
where the brown fur would be, but the fur had not reached the outer 
surface. When suckling her young, the mother rabbit does not scratch 
away the weed and grass covering to the nest, but skillfully raises it 


and gets under it, curling herself around the outside of the nest and 
cuddling her young to the center, keeping the cover intact and every- 
thing hid. I have had them remain quiet and continue suckling their 
young when I lifted the straw covering to the nest." Mr. Mitchell 
adds that the young of the Texas swamp rabbit {Sylvilagus aquati- 
cus) are also born blind and naked. 

Prof. F. E. L. Beal informs me that he has found the nest of Syl- 
vilagus transitionalis in Massachusetts and of S. floridanus mearnsi 
in Iowa containing newly born young which were still blind and 
naked. A set of large embryos of Sylvilagus nuttalli grangeri, col- 
lected by Vernon Bailey in Wyoming, are without a trace of hair. 
Bailey made a memorandum at the time of collecting these specimens 
that they were nearly ready for birth.® 


The Leporidse are practically of world-wide distribution, but are 
not native to Australia nor to the majority of oceanic islands. The 
family is divided at present into nine recognizable genera. Of these 
only one, the circumpolar genus Lepus, inhabits parts of both the Old 
and the New World. 

In all the Old World there are now six recognized generic types, 
two of which, Lepus and Oryctolagus, are wide ranging. The others, 
Pronolagus (South Africa), Nesolagus (Sumatra), Caprolagus 
(Southern Himalaya), and Pentalagus (Liu Kiu Islands, off 
Japan), are widely scattered and comparatively local. 

The number and variety of forms of the Leporidse appear to be 
greater in North America and fewer in South America than in any 
of the other continental areas. Of the four genera inhabiting North 
America, one {Lepus) is circumpolar; two (Brachylagus and Rome- 
rolagus) are peculiar to this continent, and the other {Sylvilagus) 
is common to both North and South America. In North America the 
genus Lepus is represented by two subgenera, the typical subgenus 
Lepus of circumpolar distribution and the local subgenus Macroto- 
lagus. Brachylagus and Romerolagus are monotypic genera of local 
distribution. Sylvilagus is divided into two subgenera (common 
to both North and South America), of which typical Sylvilagus 
reaches its highest development in North America, and Tapeti, with 

As this paper is passing through the press the National Museum has received 
a litter of six very young Sylvilagus floridanus mallurus collected at Cleveland 
Park, Washington, D. C, June 6, 1909, by Dr. A. Hrdlicka. They are apparently 
several days old, but the eyes are closed, the ears are like rounded fleshy pads, 
and the body is thinly covered with the fine short tips of the starting pelage, 
through which the skin is apparent. They are very different from young Lepus 
of the same age, and furnish additional evidence that the young of Sylvilagus 
are blind and naked at birth. 


the greatest range of all American subgenera of rabbits, extends 
from the Dismal Swamp of Virginia to northern Patagonia and 
reaches its greatest development in South America. 

The total range of the family in America covers the entire breadth 
of the continents, and extends from 83° north latitude, in northern 
Greenland, south to beyond 40° south latitude in northern Pata- 
gonia. Its vertical range extends from sea level to above timberline, 
reaching an elevation of more than 14,000 feet on some of the high 
mountains of Mexico. 

The Leporidse of North America reach their greatest development 
in abundance of individuals and in number of specific and sub- 
generic types on and about the immediate borders of a great elevated 
interior region, extending in a northerly and southerly direction 
from the northern United States to central Mexico. (See fig. 1.) In 
the United States the northern part of this region coincides with the 
Great Basin area, whose limits may be given roughly as reaching on 
the east to the Eocky Mountains, on the north to the mountains of 
central Idaho and the northern border of the Plains of the Colum- 
bia, and on the west to the Sierra-Cascade mountain system. From 
the southern border of the Great Basin it extends southeasterly across 
the plateaus of Arizona and New Mexico and thence south to include 
the Tableland of Mexico. In Mexico it is limited on the west by the 
Sierra Madre ; on the east by the Cordillera of the East, and on the 
south by the southern border of the Vallev of Mexico and Plains of 
Puebla. The Desert Plateau region is about 2,000 miles in length, 
north and south, and is broadest in the northern half, where it reaches 
a width of about 800 miles; to the southward it narrows to a blunt 
point. It is made up mainly of elevated treeless plains averaging 
from 3,000 to 7,000 feet above sea level in the north, and gradually 
decreasing to from 3,000 to 5,000 feet near the Mexican boundary, 
whence it rises gradually southward to 6,000 or 8,000 feet on the 
Plains of Puebla. Scattered over these irregular plains are nu- 
merous more or less isolated mountains and small ranges. The 
climate throughout most of the area is hot and extremely arid in 
summer. So scanty and irregular is the rainfall that the vegetation 
of the plains consists largely of scrubby shrubs and peculiar desert 
forms of plant life, such as cactuses, yuccas, and agaves. The streams 
are often bordered with willows and cottonwoods. The tops of the 
mountains, when sufficiently high, are usually covered with open 
coniferous forests. The plains within this region lie mainly within 
the arid upper and lower Sonoran life zones. From its climatic and 
topographic features this great interior area may be called the 
American Desert Plateau region. 

The rabbit fauna of the Desert Plateau includes representatives of 
all of the four genera and all but one of the subgenera known to 




occur in North America. The missing subgenus, Tapeti, belongs 
mainly to tropical America and the southeast coast region of the 
United States, and is preeminently a forest-loving group. One 
representative of Tapeti, Sylvilagus gabbi truei, lives along the sea- 

Fig. 1. — Map of the American Desert Tlateau region, within which the Leporidce of America 
reach their greatest development. 

ward slope of the Cordillera forming the east border of the Desert 
Plateau in Mexico. 

The area richest in hares and rabbits within the American Desert 
Plateau is near its extreme southern end. Here, within a district 

85595— No. 29—09 2 


40 miles in diameter, about the eastern border of the Valley of Mexi- 
co, live representatives of three genera and six well-marked species, 
as follows : Lcpus calif ornicus festinus, L. callotis, Sylvilagus flori- 
danus orlzahau S. auduboni parvulus, S. cunicidarius, and Romerola- 
gus nelsoni. 

Elsewhere the nearest approach to this local abundance of species 
is near the extreme northern limit of the Desert Plateau in southern 
Idaho, where in a similarly limited district live three genera repre- 
sented by five species, as follows: Lepus campestris townsendi, L. 
ccdiforn'u us wdllawalla, L. bairdi, Sylvilagus nuttalli, and Brachy- 
lagus idahoensis. 

These two large local assemblages of species suggest the possi- 
bility that the Desert Plateau has had two centers of development and 
distribution of rabbits. The northern part appears to have developed 
Brachylagus idahoensis and Sylvilagus nuttalli in addition to the 
black-tailed jack rabbits of the Lepus calif ornicus group. The 
southern end of the Desert Plateau produced Romerolagus nelsoni 
with the largest and most strongly marked species of cottontail, 
Sylvilagus cunicularius, and the peculiar group of white-sided jack 
rabbits of which Lcpus callotis is typical. The distribution of the 
two groups of black-tailed jack rabbits is especially suggestive in 
this connection, as the gray-sided or californicus group is abundant 
in the United States, and decreases in number of forms and indi- 
viduals south of the Mexican boundary, while the white-sided or 
callotis group is most abundant in Mexico, and ends abruptly a little 
north of the Mexican boundary. 

The Desert Plateau, within which the American Leporida? have 
developed so greatly, is characterized also by various other desert- 
loving mammals, especially rodents, which appear to have originated 
within its confines and thence to have extended their ranges over 
suitable adjacent regions. The most striking of these are the numer- 
ous pouched rodents belonging to the family Geomyidse (Geomys, 
Zygogeo?nys, Platygeomys, Cratogeomys, Pappogeomys, and Tho- 
momys) and the family Heteromyidse, including the kangaroo rats 
(Perodipus, L>ipodo?/iys, M icrodipod ops) and pocket mice (Perogna- 
thus, Heteromys). 

The scarcity of rabbits, both individuals and species, in such humid, 
heavily forested sections as exist on the northwest coast and even 
in the wooded eastern third of the United States is in strong con- 
trast to their abundance on the arid plains of the Desert Plateau. 

The vertical range of rabbits appears to be governed only by the 
presence or absence of sufficient vegetation for food and shelter, and 
extends from the tropical coast to above timberline, sometimes on the 
lofty volcanoes of Mexico reaching an altitude of over 14,000 feet. 
This great difference of altitude is covered in Mexico by the com- 

1909.] DISTRIBUTION. 19 

bined ranges of two geographic races of the most widely distributed 
cottontail rabbit, Sylvilagus florklanus. One of these, S. f. con- 
nectens, occupies the tropical coast region and lower slopes of Mount 
Orizaba ; the other, S. f. orizaba?, ranges thence to above timberline. 

From the northern border of the United States to the arctic re- 
gions live various members of the subgenus Lepus. The northern- 
most of these is a group of species occupying the desolate arctic bar- 
rens and known as arctic hares, which form part of a group of closely 
related species having a circumpolar distribution. 

The other two groups of species in the American section of the 
subgenus Lepus are the white-tailed jack rabbits (L. carmpestris) 
and the varying hares belonging to the Lepus americanus group. 
Both groups inhabit a more southerly range than the arctic hares, 
and are peculiar to North America. 

Ninety-seven species and subspecies of hares and rabbits are here 
recognized as living within the limits of North America. Of these, 
48 have their ranges wholly north of the northern border of Mexico, 
34 live wholly south of that line, while 14 occupy territory on both 
sides of the border. Fifty-four species and subspecies, or more than 
half the entire number known in North America, have all or part 
of their ranges within the borders of the United States exclusive of 
Alaska. Sylvilagus ftoridanus chiapensis reaches Nicaragua and 
S. f. aztecus ranges to northern Costa Rica, but Sylvilagus gabbi 
and its two subspecies, truei and incitatus, are the best known rabbits 
in the country between the southern border of Mexico and Panama. 

As would be expected, various types of rabbits have spread from 
their center of abundance on the Desert Plateau, easterly across the 
Rocky Mountains and over the Great Plains, and westerly through 
passes in the mountains to the Pacific. In the extreme southern 
United States and northern Mexico the continent narrows and is so 
homogeneous in climate and other physical characteristics that the 
Desert Plateau subgenus, Macrotolagus, ranges entirely across and 
touches both coasts. 

Representatives of only two Desert Plateau subgenera, Sylvilagus 
and Macrotolagus, extend their ranges beyond the Isthmus of Tehuan- 
tepec, the last named passing the isthmus only a short distance. 
This would appear to indicate that the isthmus once formed a barrier 
which these rabbits have crossed in comparatively recent time. On 
the other hand, the tropical American subgenus, Tapeti (including 
the swamp rabbits of the southeastern United States), which is 
widely represented by many species in South America, appears to be 
intrusive north of the Isthmus of Tehuantepec. 

Tapeti, like all other peculiarly American rabbits, undoubtedly 
originated in North America north of the Isthmus of Tehuantepec. 
This probability is strongly supported by the close relationship be- 


tween the subgenera Tapeti and Sylinlagus. In fact Tapeti appears 
like an offshoot from the same ancestry as the subgenus Sylvilagus, 
developed by isolation in the Tropics. The ancestors of Tapeti must 
have ranged from the north to beyond the Isthmus of Tehuantepec 
and have been isolated in Central and South America sufficiently long 
for the development of the present subgeneric characters. After- 
wards, because of changed physical conditions, the barrier at the 
isthmus was removed, and the intrusive movement of Tapeti to the 
north began. The subgenus worked along the eastern coastal region 
as far as the southeastern United States, after which a change of 
climatic conditions in the coast region of southern Texas and north- 
eastern Mexico caused a break in the continuity of the range of Tapeti 
whereby the ancestors of the swamp rabbits of the United States 
were isolated from their close relatives, the wood rabbits of the 
tropical forests in eastern Mexico. 


Changes in the distribution of a number of American hares and 
rabbits appear to be taking place continually. Some of these are 
temporary, as when through disease certain districts are depopulated, 
only to be reoccupied a few years later. But the main and most 
permanent changes of distribution are caused by man. The extension 
of the farming area in the United States and Canada, deforestation 
of the county, and destruction of many of the natural enemies of 
cottontails, such as birds and beasts of prey, has resulted in consider- 
able permanent extensions of the ranges of several species. It is 
altogether probable that previous to the settlement of the country 
and its deforestation cottontails were unknown in a large part of 
the eastern United States. Of some extensions of their ranges we 
have definite records. Mr. J. H. Fleming writes that the cottontail 
(S. f. mearnsi) is not considered to have been indigenous in any part 
of Ontario, Canada. It was first recorded at Niagara in 1871, and 
since then has spread gradually northward. In January, 1908, 
Fleming reported it from the south shore of Lake Simcoe, Ontario, 
and from well along the Canadian shores of Lakes Huron and Onta- 
rio, and Gerrit S. Miller, jr., records its eastward extension from 
Geneva to Peterboro, in central New York, subsequent to 1870. 

Within an even more recent period Dr. A. K. Fisher has noted the 
extension of S. tramitionalis northward to the shore of Lake George, 
where it was numerous in the fall of 1907. 

Vernon Bailey informs me that within the last ten or twelve years 
Lepus campestris has followed the extension of farms in central 
Minnesota and moved eastward across the Mississippi from its former 
range on the prairies for 50 or 00 miles to Elk River. In the early 
eighties the cottontail (S. f. mearnsi) in this same region extended 

1909-] HABITS. 21 

its range north from near Minneapolis, and now has occupied the 
country to a point well north of Elk River, in Minnesota, and to 
Gordon, in northwestern Wisconsin. 

A progressive restriction of the area occupied by varying hares 
appears to be taking place all along the southern border of their range. 
This is largely due to deforestation, and is accompanied by an equally 
steady coextensive northward extension of the range of the cottontails. 

In the southern half of New York and the New England States 
varying hares have nearly or quite disappeared from many localities 
where they were formerly numerous. They were once abundant in 
the forested parts of the Canadian and transition zones in Pennsyl- 
vania and New Jersey, but are now nearly gone in the latter State, 
and remain only in many isolated areas in the Allegheny and Blue 
Ridge mountains of Pennsylvania. Farther south their range in the 
mountains of Virginia and West Virginia is becoming similarly re- 
stricted. The lessening range of this hare is accompanied by the in- 
creasing range of the cottontails, Syhnlagus f. mallurus, /S. f. mearnsi, 
and S. transitionalis. 

In addition to self-operating changes in the distribution of these 
animals, man has interfered directly in a few cases, and has intro- 
duced species where they were not native. The introduction of vary- 
ing hares in Newfoundland and of varying hares and cottontails on 
Nantucket Island may be cited as examples. 


The habits of the American cottontails and jack rabbits in the well- 
populated parts of the United States are fairly well known and are 
generally considered typical of the rabbit family as a whole. This 
belief holds true for a majority of the species, but among the others 
are some interesting, and in a few cases extraordinary, differences in 
habits. Much, however, yet remains to be learned of the life his- 
tories even of the best-known species. Practically all the species are 
mainly crepuscular or nocturnal, although some of them, especially 
the jack rabbits, often move about by day, particularly in cloudy 
weather. When hares or rabbits become very abundant and food is 
scarce, they are often forced to become more diurnal than under usual 
conditions. All the species of Lepus make nest-like ' forms ' in 
sheltered spots, in which they conceal themselves during the day; 
although in summer Lepus campestris sometimes uses the deserted 
holes of other mammals, and in winter burrows into the snow for 
protection from the bitter cold, and from the birds and beasts of prey 
on the open plains where it lives. 

Most members of the genus Sylvilagns use both forms and the de- 
serted burrows of other mammals, or find shelter under rocks, roots of 


trees, and similar places. Forms are in common use in summer and 
in regions which have a warm winter climate, but some species ha- 
bitually use old burrows, which they sometimes enlarge. The forms 
are usually made under the shelter of dense herbage or under low 
brushy growths, and the owner spends the day in them regularly for 
considerable periods. The females of many, if not all, species of 
Sylvilagus make soft, warm nests of fine grass, leaves, and other veg- 
etable material, lined with hair from their own bodies, and in these 
nests the young are born and lie concealed, like mice in a nest, while 
small and helpless. The nests of cottontails are usually placed in a 
bowl-shaped depression in the ground in some sheltered spot, and 
during the absence of the parent the young are covered and com- 
pletely concealed by the material of the nest. At such times the top 
of the nest is so like the surrounding surface of the ground, on which 
lie dead leaves and grasses, that its presence can be detected only by 
chance. Various subspecies of Sylvilagus auduboni, a group living 
mainly on more or less open plains of the arid regions, commonly 
need more secure shelter than is afforded by a form in the scanty 
herbage of their home and, more frequently than the subspecies of 
floridanus, they occupy the deserted burrows of other mammals or 
the secure refuge of holes under rocks, or crevices among stone walls 
and in rocky ledges. They even take possession of the space under 
floors of outbuildings about ranches, and I have found families of 
six or eight living under deserted ranch houses. In some cases they 
enlarge burrows or dig the dirt from between rocks or under boards 
to make an entrance under a house, but appear never to make entirely 
new burrows. 

Brachylagus idahoensis is the only American species known habit- 
ually to make its own burrows in the ground. Vernon Bailey has 
discovered that, while it frequently makes use of deserted badger 
holes, it commonly digs burrows, which are often connected on the 
surface by well-marked runways. 

Romerolagus nelsoni makes its own runways, and tunnels among 
dense masses of coarse grass ; in fact, it has many of the habits of a 
giant field mouse (JJ icrotus) . The tropical representatives of Tapeti 
within our limits live in dense undergrowth and make runways 
through the thickets. The swamp rabbits of the same subgenus live 
in the wooded lowlands of the southeastern United States, and are 
remarkable for liking wet situations. Their habits are semiaquatic, 
and they swim with the greatest freedom. Bachman's interesting 
account of Sylvilagus palustiis gives a good idea of the strange habits 
of species of this group, which are very different from those of any 
other American rabbits. This author states that S. palustris makes a 
domed nest for its young with an entrance on one side. 

a Quadrupeds of North America, I, pp. 152-155, 1S49. 

1909.] DISEASES. 23 


In the Western United States and Canada rabbits, including jack 
rabbits, varying hares, and cottontails, periodically become exces- 
sively abundant. Then a fatal disease breaks out, apparently an 
epidemic, and within two years or so they almost totally disappear 
from vast areas. The exact nature of these epidemics remains to 
be determined. MacFarlane speaks of a disease occurring each 
decade among the varying hares in northern Canada, and states 
that it " affects the head and throat of the victims." In the upper 
Mackenzie River region during the winter of 1904 E. A. Preble 
found varying hares extremely numerous, and great numbers were 
dying from an epidemic. His examinations showed that the throats 
and lungs of the diseased animals were much inflamed, the viscera 
excessively moist, and their flesh and skin very dry. The epidemic 
witnessed by Preble continued the following year or two and ex- 
tended over a large part of Canada, even reaching to the Magdalen 
Islands, off the east coast. Before the disease reached these islands 
varying hares were extreme^ abundant ; but in the summer of 1907 
W. H. Osgood spent a large part of his time for a week, aided by 
native hunters, trying to secure there specimens of these animals, 
without even seeing fresh signs of one. This case is typical of the 
conditions which usually prevail over the range of a species which, 
after a period of great abundance, has suffered from one of these 
deadly epidemics. There is a general belief in the areas where 
these epidemics occur that they recur with some regularity. Accord- 
ing to Bendire the people of southern Idaho thought they occurred 
among the jack rabbits every five or six years. In the Mackenzie 
region Preble learned that the residents believe the} 7 recur about 
every seven years. 

Mr. A. G. Maddren reports that during the winter of 1906-7 
most of the varying hares died in the Copper River region, Alaska. 
During the summer of 1907 he saw quantities of white fur in patches 
wherever he went in this region, the fur being often lodged in the 
bushes at the level of the winter snow, showing that the animals 
had died in midwinter. During the summer of 1908 these hares 
were extremely scarce along the entire course of the Innoko River, 
thus showing that the same epidemic that killed them in the Copper 
River country had extended across into the lower Yukon Valley. 
During the winter and spring of 1908 Mr. Charles Sheldon noted 
the extreme scarcity of varying hares at the north base of Mount 
McKinley and in the Tanana River Vallej 7 . 

Jack rabbits, especially in California, often have under the skin 
of the body large, watery, tumor-like gatherings which contain 
the larvae of a tapeworm (Taenia serialis). The skin of jack rab- 


bits, and less commonly of cottontails, is sometimes infested with 
the larva? of a fly. These grubs are known as ' warbles.' A more 
curious but less serious disease is most common among cottontails 
west of the Mississippi River. This is the growth of long, conical, 
horn-like excrescences on the skin, usually on the head, which ap- 
pear to have a close similarity to warts and not to affect the general 
health of the victim. These excrescences vary in number from one 
to half a dozen and are an inch or two in length. They stand out 
at right angles from the skin and look like little horns. Sometimes 
they grow symmetrically on the top and sides of the head, giving 
the animal a remarkable appearance. 


From Preble's observations among the varying hares, the number 
of young in a litter is reduced during the periods of epidemic. 
MacFarlane says: "A litter usually consists of three or four; but 
when on the ' periodic ' increase [after an epidemic] females have 
been known to have as many as six, eight, and even ten at a time, 
and then gradually return to three or four." This increased birthrate 
helps to account for the extraordinary rapidity with which ranges 
are restocked with rabbits after epidemics; for comparatively few 
are left alive within the depopulated areas. 


The typical color pattern of American rabbits consists of a nearly 
uniform grayish or buffy brownish shade over the upperparts of the 
head and body; a broad band of similar, but usually clearer, color 
across the underside of the neck; uniform white or whitish over all 
or most of the remainder of the lowerparts, and a patch of unmixed 
gray, buffy, black, or rusty on the nape. 

In summer pelage the prairie hare (Lepus campestris) and the 
varying hares, and in ordinary pelage Bvachylagus and Romerolagus, 
have the back and sides of a nearly uniform color. When the sides 
of any of the foregoing species are slightly paler than the middle 
of the back, the difference is due to the greater abundance of 
black hairs on the back. On the other hand, most of the cottontails 
(genus Syluilagus) and most of the subspecies of Lepus calif ornicus 
(the common jack rabbits of the western United States) have the 
sides distinctly paler than the top of the back, and the rump usually 
paler than the rest of the back, sometimes enough so to make a dis- 
tinct grayish rump patch in strong contrast to the darker back. In 
fresh pelage there is often a long oval darker area which covers the 
top of the back from the front of the shoulders to the rump, and is 
outlined below by a paler grayish or pale buffy wash on the surface 


of the sides and rump. This dark area may be called the mantle. 
Close examination often shows that the contrast of surface shades 
which distinguishes the dark mantle from the pale areas on the rump 
and sides extends also in a less degree to the colors of the underfur, 
so that the contrasting areas are still apparent when the outer hairs 
wear away and expose the underfur. The same pattern — a dark 
mantle covering the top of the back and outlined by pale sides and 
rump — is well marked in the winter pelage of Lepus campestris 
along the southern border of its range (Kansas and Colorado), 
where it does not become entirely white. The real significance of 
the pale sides and rump contrasting with a dark dorsal area is strik- 
ingly shown in the Lepus callotis, or white-sided group of jack 
rabbits, which includes Lepus callotis. L. faric/ularis, L. altamirce, 
L. gaillardi, and L. alleni. with the subspecies of the two last named. 
This group of species is characterized by a dark buffy mantle cover- 
ing the top of the back and sharply outlined by whitish or iron-gray 
sides and rump, the white or pale gray of the sides being continuous 
with the white on the abdomen. That the striking color pattern of 
these species is a form of directive coloration, as in the case of the 
white rump patch of the prong-horn antelope, is proved by observa- 
tions made by Goldman and myself in Mexico. We have started 
numerous individuals of L. callotis, L. favigularis, and L. alleni 
from their forms, and seen them move off in short zigzag courses, 
and at each turn the dark mantle was shifted to the opposite side 
and the whitish area of the side drawn up nearly or quite to the 
dorsal line, thus presenting to our view an entirely whitish side, 
which flashed out brilliantly in the sunlight. At a distance, during 
this performance, the jack rabbits appeared to be almost entirely 
white. A more detailed account of this habit is given in the prelim- 
inary notes to the descriptions of the members of this group (p. 115). 
It may be added here that these species, like the antelope, commonly 
live on open plains. The frontispiece illustrates the manner in which 
the dark mantle is drawn over and the white area enlarged. 

The discovery that there is a group of jack rabbits in which the 
color pattern is used for a definite purpose raises an interesting ques- 
tion concerning the significance of the traces of this same pattern in 
other species, both of Lepus and of Sylvilagus. Are they instances 
of parallel development toward the same white-sided pattern as that 
of callotis, or are these species losing a pattern which, once common 
to all, is now fully retained only by the white-sided jack rabbits of the 
southwestern United States and Mexico? The theory of parallel 
development appears to fit the case most reasonably. 

The distribution of color on the majority of American rabbits 
living in temperate and hot climates — darkest on top of the back, 
paler on the sides, and white on the underside of the body — con- 


forms to the color scheme best adapted to protective purposes as 
demonstrated in his study of birds and mammals by Abbott H. 
Thayer. The arctic hares in gray summer pelage reverse this dis- 
tribution of color and have the top of the back lighter than the sides 
and the dusky color on the sides increasing in intensity downward, 
thus becoming darkest along the lower flanks next to the pale ab- 

All of the members of the subgenus Macrotolagus, which includes 
the white-sided as well as the gray-sided, or calif ornicus, group of 
jack rabbits, have a distinct black line along the middle of the lower 
rump and upperside of the tail. The arctic hares, and the prairie 
hare in most of its range, have the top of the tail pure white. Lepus 
campestris townsendi, however, commonly has more or less dusky or 
black on the upperside of the tail. This character is most strongly 
marked in specimens from southwestern Colorado. One individual 
from Coventry, Colorado, has a broad black line on the tail about as 
strongly marked as in Lepus c. texianus. Here appears to be another 
instance of parallel development in an area where two distinct species 
are subjected to the same conditions. The upperparts of the cotton- 
tails are usually a mixture of gray, buffy, and dusky, producing a 
neutral shade very effective for purposes of concealment. The 
result of environment on these dull colors has been to bring about 
close resemblance or parallelism between races of distinct species oc- 
cupying the same or closely adjacent territory. For instance, speci- 
mens of Sylvilagus auduboni warreni and S. nuttalli pinetis are often 
practically indistinguishable in color. The same close resemblance 
appears between specimens of S. auduboni baileyi from the east base 
of the Rocky Mountains in Colorado and specimens of S. floridanus 
similis from the same region. Other cases of the same kind exist, 
and show that like climatic conditions often produce the same or 
closely similar colors in dissimilar species of rabbits. 


Both melanism and albinism are extremely rare among American 
rabbits. I have seen two melanistic specimens, one of Sylvilagus 
palustris paludicola and one of Lepus americanus virginianus, and 
two albinistic individuals, one of Sylvilagus foridanus mallurus and 
one of S. transitionalis. 


Among the darker colored hares and cottontails it is difficult to 
find evidence of dichromatism, but among some of the paler forms 
it is distinct. It is most evident among the paler subspecies of Lepus 
calif ornicus and Sylvilagus auduboni. Lepus c. deserticola and L. c. 
texianus, and also Sylvilagus a. arizonce, and S. a. minor, are charac- 

1909.] PELAGE. 27 

terized by the generally pale gray color of their upperparts, but oc- 
casional individuals occur sporadically throughout the ranges of 
these forms which are strongly buffy or even ochraceous buffy. 
These individuals are often indistinguishable in color from another 
subspecies occupying a different area. The converse of this condi- 
tion, an occasional pale individual in the range of dark forms, ap- 
pears to be less common, though it sometimes occurs. 


The pelage of rabbits, as of other mammals, varies in length and 
density according to the severity or mildness of the climate. This 
is well illustrated in the remarkable contrast between the long, dense, 
Avoolly coat of Lepus groenlandicus in the far North, and the short, 
thin, and rather coarse coat of L. favigularis from the tropical coast 
of southern Mexico. Similar differences in smaller degree exist be- 
tween species of warm lowlands and those of adjacent cool elevated 
mountain slopes. 

The color of rabbits responds readily to climatic influences. This 
is most strikingly shown by the two annual molts of the northern 
species, which become white in winter and dark in summer. In 
north Greenland, however, where areas of perpetual snow are more 
or less abundant, Lepus groenlandicus remains white throughout the 
year. In Kansas and parts of Colorado Lepus campestris changes 
into a winter coat only a little paler than the summer pelage, al- 
though farther north, where the snow is more abundant and lies 
longer, it becomes entirely white. Species of the arid regions are 
light colored and become paler or grayer with increase of aridity, 
while those of humid regions are darker with deeper shades of buffy 
and rusty. Specimens from some localities appear to indicate a small 
but appreciable difference in the general shade of the upperparts 
in the same locality due to marked temporary variations, such as a 
wet or dry summer or an open or snowy winter. 

The pelage is heaviest on the top of the back and thinnest on the 
abdomen. It is made up of three sets of hairs, which are most 
strongly differentiated on top of the back and may be characterized 
as follows: (1) A fine, short, and dense underfur; (2) a longer, thin- 
ner and coarser coat of hairs, the tips of which overlie and conceal 
the underfur; and (3) a still longer, coarser, and more sparsely dis- 
tributed set of hairs, the tips of which overlie the shorter middle 
coat. The underfur is usually buffy or gray, with a strongly con- 
trasting darker tip; the middle coat of hairs usually has a dusky 
tip with a broader subterminal zone of buffy or grayish; and the 
coarse longer hairs, most abundant along the middle of the back, 
are usually glossy black, at least on their terminal half. These long 
black hairs overlie all the rest of the pelage, and often give the effect 


of a strong blackish wash over the back. The full growth of the 
long black hairs characterizes the adult pelage, but they vary in 
length and abundance even in geographic races of the same species. 
The absence or slight development of the black hairs in the juvenal 
and post juvenal pelages is largely the cause of the paler color of the 
upperparts in these pelages in comparison with the adult condition. 
All the arctic and other northern hares in winter pelage are more or 
less exceptions to this color distribution. They become pure white 
externally, and the arctic hares are entirely white, including the 
underfill*. The varying hares and white-tailed jack rabbits, how- 
ever, always have the underfur bicolored, though paler in winter 
than in summer. 


Three distinct pelages due to age appear to be common to all 
American hares and rabbits. These may be characterized as follows : 

1. Juvenal pelage. — This is soft and woolly and may be compared 
to the downy plumage of young birds. It is perhaps of somewhat 
longer duration than the downy plumage, but usually gives way, 
when the animal is less than half grown, to the post juvenal or 
second pelage. 

2. Post juvenal pelage. — The term post juvenal applied to the plum- 
age of birds following the juvenal state is exactly applicable to 
a similar condition existing in the Leporidse. This is characterized 
by a much greater development of the middle, or hairy coat, over- 
lying the underfur than in the juvenal condition. The overlying 
coat is composed of finer hairs than in the adult, and usually averages 
paler, with a more finely grizzled, or ' salt and pepper,' appear- 
ance. This paler color is due mainly to the absence of the long 
black hairs of the adult and to the reduced amount of dusky on 
the tips of the middle coat, which results in a fine mixture of the 
dusky with the ground color, instead of, as in adults, an overlying 
black wash. There is a general resemblance to the adults in the 
postjuvenal condition, but the absence of the coarsening, as well 
as darkening, effect of the long black hairs on the back, as well as 
the paler and more finely grizzled colors, usually render individuals 
in this pelage readily separable from adults. 

The postjuvenal pelage is usually retained until the animal is 
nearly full grown, when it gives way to the adult stage. Occasional 
breaks appear to occur in the sequence of the three pelages, and 
individuals not much more than half grown appear to assume the 
adult pelage. This break is only apparent, however, and is due to 
marked individual acceleration of the pelages by which the post- 
juvenal stage is much shortened. This may indicate evolution toward 


the eventual suppression of this pelage, leaving merely the ju venal 
and adult. 

3. Adult pelage. — This is the final condition which replaces the 
postjuvenal pelage as the individual approaches maturity. It is 
characterized by the coarser hairs of the middle coat with darker 
and more coarsely grizzled colors, and by marked development of 
the long black hairs which overlie the back. 

The postjuvenal pelage of American rabbits appears not to have 
been recognized by previous authors, and has resulted in misunder- 
standing regarding certain species. The element of individual varia- 
tion, actually great, has been made to appear even greater by speci- 
mens in postjuvenal condition. The contrast between individuals 
in postjuvenal and adult pelage is greatest in those species or sub- 
species in which adults have the heaviest growth of long black hairs 
overlying the surface of the back. In forms in which the black 
hairs are least conspicuous in adults the postjuvenal and adult 
pelages are much more alike, and are distinguishable mainly by the 
distinctly finer or more ' pepper and salt ' character of the grizzling 
on the upper parts, coupled with the generally slightly paler colors 
of the young. 


By peculiarities of molting, American rabbits are separable into 
two classes: (1) Those which have two annual molts, and (2) those 
which have only one annual molt. All American species of the 
genus Lepus (except the subgenus Macrotolagus) and the genus 
Brachylagus belong in the first category, while all of the genus 
Sylrilagus, the subgenus Macrotolagus of the genus Lepus ', and 
probably Romerolagus belong in the second class. 


The species belonging to the northern subgenus Lepus and the 
genus Brachylagus have two annual molts, which occur in spring and 
fall. These molts result in distinct and usually strongly contrasted 
summer and winter pelages. While in most species these summer 
and winter pelages are very unlike, there are a few exceptions. Lepus 
gramlandicus throughout its range, and Lepus arcticus in the north- 
ern part of its range, are white throughout the year, though the white 
summer pelage of both is duller and scantier than the winter pelage. 
L. campestris is dull buffy yellowish in summer, and in the northern 
part of its range, white in winter; while on the southern border of 
its range, in Kansas and Colorado, the winter pelage is nearly as 
dark as that of summer. L. washingtoni of the subgenus Lepus is 
the only known American member of this subgenus which has prac- 


tically the same brown color in winter as in summer. The other mem- 
bers of this subgenus are brown in summer and white in winter, 
though the underfur remains bicolored throughout the year, but is 
paler in winter. Brachylagns is grizzled buffy brown in summer, 
with a general resemblance in color to various forms of Sylvilagus. 
The type and topotype of B. idahoensis, collected in September, have 
an abundant silky-haired pelage of a nearly uniform pinkish drab, 
different from any other American species at this season ; some freshly 
molted fall specimens of Sylvilagus a. bailey i from Wyoming, how- 
ever, have considerable resemblance in general color to this pelage 
of /'dahoensis. 

The change in color from the white winter pelage of northern 
species to the dark summer coat, or vice versa, is accomplished so 
gradually that at certain stages it appears like a change in the color 
of the hairs instead of a molt. Examination of abundant material 
confirms the fact of a complete molt, as was definitely proved some 
years ago by Doctor Allen in his paper on the changes of pelage of 
the varying hare. a 

The molts usually begin about the head and feet and proceed more 
or less irregularly over the body, but there is no absolute rule, and 
patches of new pelage may appear on any part of the body, especially 
if the old coat has been thinned by abrasion or other local cause. 

In spring, just before the molt, the long white surface coat of the 
varying hares often wears away more or less completely, and leaves 
the buffy or dusky underfur exposed, thus producing a striking 
change in color without a molt. Late in summer, preceding the 
fall molt, there is often a similar wearing away of the outer coat, 
thus leaving the woolly underfur exposed and again changing the 
general shade of the upperparts. 

Adults of Lepus hairdi and extreme northern representatives of 
Lepus americanus appear to have white feet throughout the summer. 
The young of these white-footed animals have dark colored or brown- 
ish feet through the ju venal and post] u venal pelages. Adults of 
loashingtoni and the southern subspecies of americanus have dark 
colored or mixed white and brown feet in summer. 

Effect of seasonal differences on time of molt. — The time of the 
spring and fall molt of the subspecies of Lepus americanus varies 
with the character of the season. An early spring or fall brings on 
the molt a month or more earlier than a late one. A good illustra- 
tion of the influence of season on molt was afforded by L. a. stru- 
thopus in Nova Scotia during the mild late fall of 1907. Several 
specimens from Kings County collected as late as November 25 were 
just beginning to assume the white winter coat, and others from the 

°Bull. Am. Mus. Nat. Hist., VI, pp. 107-12S, May 7, 1S94. 

1909.] ANNUAL MOLT. 31 

same place collected on December G and 7 were not yet in full winter 
pelage, though ordinarily pure white at this time. 

Decrease of amount of white in winter pelage of L. americanus 
southward. — Among the subspecies of L. americanus there is much 
difference in the thickness on the back of the overlying white winter 
coat. The northern forms have a thick, heavy layer of white com- 
pletely concealing the buffy surface of the underfill*. In the southern- 
most forms, including virginianas, struthopus, and phceonotus, the 
overlying coat of white is so thin that the buffy underfur often 
slightly tinges the generally white shade and distinctly shows 
through wherever the white surface hairs are even slightly dis- 
arranged, while the ears, head, and tops of feet often have more or 
less rusty buffy on the surface. Winter specimens from Newfound- 
land, like Nova Scotia specimens, have a very thin layer of white 
on the surface of the back, with the buffy underfur showing through, 
in strong contrast with the much purer white specimens from the 
neighboring coast of Labrador. 


Adults of the southern groups of rabbits, including the genus 
Sylvilagus, the subgenus Macrotolagus of the genus Lepus (and 
probably the genus Romerolagus) , appear to have but one molt 
annually. In the great majority of the forms this occurs the latter 
part of summer or in fall, generally between the middle of August 
and the middle of October ; but in a few subspecies the change often 
begins in June or July. The ordinary exceptions to this rule in 
adults are the occasional individuals which through malnutrition or 
illness have had the regular course of life processes disarranged. 
Such individuals are likely to retain the old pelage longer than 
usual and to molt at unseasonable times. Occcasional individuals 
molt very early in summer. In addition, every large collection con- 
tains specimens, especially from mild southern climates, which have 
taken on fresh pelage at odd times of the year. Examination of the 
skulls usually proves that these are young animals assuming their 
post juvenal or first adult pelage in the regular sequence. Such cases 
have no bearing on the regular molt of adults. 

The fresh fall or winter pelage is much darker and richer than 
that of any other period; the long overlying black hairs are most 
conspicuous at this time, and in some forms produce a thin dark 
shading to the upperparts and in others a heavy black wash. 

There is a progressive wear and fading of the pelage from its 
assumption until the molt the following year. In the more humid 
regions, with less sunshine and with an abundance of sheltering 
vegetation, the colors fade more slowly, and the rabbits rarely pre- 


sent the ragged and scorched appearance common in arid regions. 
The species of the humid areas are darker in color, and usually have 
more buffy or buffy brown in the upperparts, which, when the pelage 
is worn and faded, often changes to a distinctly more rusty or rusty 
reddish shade. 

In fresh pelage the tips of the hairs on the rufous areas of the 
nape and legs are paler than the underlying color, and thus dilute or 
dull the intensity of the rufous. The wearing away of these pale 
tips gives the rufous areas a deeper or more intense color in worn 
spring specimens than in those in fresh fall pelage. As the general 
color of the upperparts in spring is paler than in fall and the rufous 
leg patches brighter, the variation in the amount of contrast between 
these color areas in the same subspecies at different seasons is often 

In dry regions of abundant sunshine and sparse vegetation the 
colors of the fresh pelage begin to fade immediately after the molt 
and soon show an appreciable loss of intensity. The fading of the 
general colors is accompanied by the wearing away of the long black 
hairs overlying the fur. This fading and wear continue steadily 
throughout the year until the next molt. By spring the colors have 
become so much paler that frequently specimens representing the two 
seasons are very unlike. Sometimes the long hairs are entirely worn 
away, and the exposed underfill* is so worn that the pelage presents 
a ragged woolly appearance. The bleaching of the tips of the middle 
coat and of the long black hairs before they wear away sometimes 
produces a dull rusty shade over the upperparts not present at any 
other time. In some individuals the buffy tips of the underfur are 
heavily underlaid by a zone of darker color. In these instances the 
wearing down of the pelage causes the upperparts to become even 
darker, or more dusky, than when freshly molted. 


The only difference in American rabbits due to sex appears to be 
in size. Very old females of both cottontails and jack rabbits are a 
little larger than males of the same age. This difference is so slight 
among average individuals, however, that in identifying specimens it 
may be ignored. 


The shade of color, size, length of ears, hind feet, and form and 
proportions of the skull are subject to marked individual variation. 

The intensity of the shade of buffy forming the general ground 
color of the body in so many species is subject to much individual 
variation, aside from seasonal changes. Among specimens in fresh 
pelage shot at the same locality on the same day the shade on the back 


may vary from pale buffy grayish to nearly ochraceous buffy. The 
sum of the seasonal and individual variations is so great that a large 
number of specimens in every considerable series, if considered by 
themselves, are extremely puzzling. 


The skulls of rabbits change greatly while passing from the young 
adult to old adult condition. This is due partly to increase of size, 
but mainly to increased ossification of the parts and consequent in- 
crease of weight or massiveness of structure. In many forms the 
rostrum, rather narrow and slender in the young adult, becomes 
strong and heavy. The supraorbitals, at first thin and slender, so 
that the interorbital width is narrow, with increased age become broad 
and heavy. The anteorbital and postorbital processes, at first of 
slender form with free ends inclosing well-marked notches, broaden 
and lengthen until the ends often touch the skull and inclose foramina, 
or even shut in and coalesce with the skull along their inner borders. 
All the parts become more massive with this increased ossification, 
until in some very old examples the character of the skull is so unlike 
that of typical specimens as to be scarcely recognizable. 

The accompanying illustration (PI. II) of three skulls of adult 
Lepus americanus virginianus from Gold, Pennsylvania, indicates the 
range of individual variation appearing in nearly all species when 
large series are available. 

Notwithstanding these wide extremes of variation, each species or 
subspecies usually has certain average skull characters peculiar to it. 
In some cases these are slightly and in others strongly marked. The 
skull characters of rabbits, which are most marked, and which serve 
best for comparison and characterization, are the size of the bullae; 
the size, form, and relative position of the supraorbital processes; 
and the size and form of the rostrum and braincase. 

The fairly well-marked skull characters which distinguish some 
subgeneric, or even generic, groups are sometimes almost completely 
bridged over by what appear to be cases of parallel development. A 
good example is Sylvilagus (Sylvilagus) f. yucatanicus, which has a 
massive skull, with the anteorbital and postorbital processes fused to 
the frontals along their entire length, and closely resembles in form 
and general appearance the skull of Sylvilagus (Tapeti) aquaticus. 
Skulls of S. transitionalis and S. f. mallurus in overlapping territory 
of the two species from southeastern New York to the mountains of 
North Carolina, while remaining unmistakably distinct, approach one 
another closely in certain characters. An equally close resemblance 
is shown between a skull of Lepus washingtoni klamathensis and typ- 
ical skulls of Sylvilagus hacJimani ubericolo7\ and also between some 
85595— No. 29—09 3 


skulls of L. campestris and L. californicus melanotis from central 

The most interesting and instructive point in connection with this 
parallel development of skulls is that the striking resemblances noted 
usually appear in individuals inhabiting the same region or neigh- 
boring regions, where they are under the influence of the same or 
closely similar climatic conditions. For example, the range of Lepus 
u\ Mamathensis is close to that of S. b. ubericolor in Oregon, though 
in a different life zone; and, as just cited, the similarity between L. 
campestris and L. californicus melanotis in Kansas is confined to indi- 
viduals from areas where both species occupy the same territory. Syl- 
vilagus f. yucatanicus lives in dense low brush and forest growth in 
a region bordering the Gulf of Mexico and having an extremely warm, 
humid summer climate much like that in which 3. aquaticus has its 
home. In this last case similarity of skull characters in dissimilar 
species occurs in widely separated areas, although the home of S. 
aquaticus is shared by another subspecies of floridanus in which these 
parallel characters do not appear. 


The main differences within specific limits are due, as would be 
expected, to changes of environment, and result in the production of 
geographic races. The amount of difference from this cause varies 
among species of the same genus or even the same subgenus. The 
geographic races of some species are not strongly marked, as in the 
case of the subspecies of the California brush rabbit, among which 
the variation of size, proportions, and color is comparatively small. 
In the subgenus Sylvildgus the extremes of differentiation among 
the subspecies of S. auduborii are less than among the forms of S. 
floridanus, although typical 81 aucluboni and 8. auduboni baileyi are 
very unlike. This difference, however, scarcely equals the contrast 
between the small gra} r S. floridanus chapmani and the large rusty 
S. f. yucatanicus. Among the subspecies of Lepus californicus the 
differences are even more striking. At first glance it seems almost 
impossible that typical L. californicus, L. c. merriami, and L. c. 
melanotis can be conspecific. In fact, these three forms were con- 
sidered by me as specifically distinct until abundant material proved 
conclusively that intergradation is complete. 


"While studying series of specimens from all parts of the vast range 
occupied by the geographic races of such species as Sylvilagus flori- 
danus and S. auduboni, I have been impressed with evidences of fluc- 
tuation of both external and skull characters. These fluctuations 


are somewhat wavelike in character and rise to central points of 
extreme development and then sink away to intermediate borders 
beyond which new waves rise. When the waves of differentiation 
are pronounced they mark recognizable geographic races. Within 
the area covered by the larger or geographically broader w r aves of 
differentiation (recognized as of subspecific value), smaller waves of 
differentiation are included, which may represent local variations 
in intensity of characters of the subspecies, or these characters may 
diminish and the variation tend in other directions, sometimes even 
closely reproducing the characters of another subspecies occupying 
a distinct area. 

In the case of wide-ranging subspecies such fluctuations are fre- 
quent, especially where the areas occupied are diversified by moun- 
tains. These fluctuations, which are sometimes extremely local, 
mark, of course, potential subspecies. Some are fairly well charac- 
terized and eventually may be named, while others are too slight to 
be formally recognized by name but well serve to illustrate the plastic 
condition of the species. The transition from one subspecies to 
another takes place abruptly or gradually in exact accord with the 
changes of environment which produce them. When specimens rep- 
resent such endless geographic variation it is often difficult to decide 
whether to retain certain forms already named or to drop them into 
the wastebasket of synonymy. The difficulties of decision are often 
increased by the fact that many geographic races have been named 
from imperfect material, and the types not infrequently prove to 
have been taken from zones intermediate between the ranges of well- 
marked forms. Hence the type is not typical and represents the 
intermediates. In such cases the most strongly marked representa- 
tives of the form in question occur only at a distance from the type 
locality. In many instances, too. the type, though from a locality 
well chosen geographically to represent the form, proves unlike the 
average, and not infrequently can not be duplicated in a large series 
of topotypes. 



The periodic destruction by disease of nearly all the rabbits over 
wide areas leaves but few individuals each time to continue the stock 
and repopulate the range. This condition must have recurred num- 
berless times in the past, and in the case of species having a broad 
distribution would appear to have provided the best possible oppor- 
tunity for the origin through isolation of many strongly characterized 
subspecies, if not of well-marked species. On the other hand, gen- 


eral similarity of climate and absence of isolation appear to be strong 
leveling influences to hold variation within certain limits. 

Lepus americanus, occupying the vast wooded area extending from 
the coast of Nova Scotia to western Alaska, has been subjected to 
numberless recurring periods of extreme abundance and extreme 
scarcity; and yet, through its extensive range, it now presents only 
a few not strongly differentiated subspecies. 


Complete isolation of rabbits under like climatic conditions may 
have little or great influence in the development of differences from 
the general stock. The small effect of isolation is shown by Lepus 
americanus struthopus on the Magdalen Islands. Another case is 
that of Sylvilagus bachmani cerrosensis, a slightly differentiated form 
on Cerros Island. On the other hand, isolation under like climatic 
conditions may give rise to marked differences of full specific value. 
This is well illustrated by Sylvilagus graysoni of the Tres Marias 
Islands, about 65 miles off the west coast of Mexico, which so closely 
resembles S. cunicularius insolitus of the adjacent mainland in gen- 
eral characters that it is impossible to doubt its origin from that spe- 
cies. In this case isolation, although under a closely similar climate, 
has been continued long enough to produce good skull characters, as 
well as other differences of specific value. 

The most extraordinary example among American rabbits of the 
results of isolation under similar climatic conditions is that of Lepus 
insularis (PL III). This jack rabbit is peculiar to Espiritu Santo, 
a small island about 15 miles long, lying 4 miles offshore in front of 
La Paz Bay, Lower California, in the Gulf of California. The posi- 
tion of the island, as well as its geological formation, and the con- 
figuration of the shore on both sides of the strait show conclusively 
that it once formed a part of the adjacent coast. That the separa- 
tion of the island was caused by the sea cutting through a narrow 
part of a former slender peninsula appears not only by the character 
of the land formations on both shores of the narrow channel but by 
the shallowness of the channel itself, which has only from 3 to 5 
fathoms of water along the submarine ridge which extends from the 
mainland shore to the island with deeper water on both sides. This 
indicates that the island was formed within a comparatively recent 
period. The hot, arid climate and the scanty vegetation on the 
island and adjacent mainland, as would be expected, are practically 
identical. On the mainland Lepus californicus xanti, a pale form 
of the California jack rabbit, is plentiful. Four miles away, on 
Espiritu Santo, jack rabbits also are common, and their general ap- 
pearance and type of skull show that they must have been derived 


from the adjacent mainland species. The resemblance ceases here, 
however, for the island animal has not only developed good skull 
characters but its colors have become so extremely intensified that it 
is commonly spoken of as the black jack rabbit. 

It has been stated in several places, mainly on Bryant's authority, 
that this dark colored jack rabbit lives among black lava rock, where 
its color is protective. We failed to see any black or even very dark 
rock on the parts of the island visited, and in every case among the 
thirty or forty of the animals seen, whether sitting still or moving, 
they were extraordinarily conspicuous. It is quite certain that the 
color of this species can not be justly cited as having anything to 
do with protective coloration. 

Probable factors in the development of this dark-colored species 
on the desert island are absence of any predatory mammals and 
extreme scarcity of birds of prey large enough to interfere with it. 
The only other instance known to me in which a mammal appears to 
defy all the laws of protective coloration is that of the black Citellus 
variegatus couchi living among the whitish limestone rocks near 
Monterey, Mexico. . The colors of both the black jack rabbit and the 
black ground squirrel in their native haunts are in exaggerated con- 
trast to their surroundings. 


In his Classification of the Hares and their Allies,® Doctor Lyon 
recognized five genera of North American hares and rabbits, as fol- 
lows: Lepus, Sylvilagus, Limnolagus, Bracliylagus, and Rotrherolagus. 
In addition he divided the genus Lepus into three subgenera, Lepus, 
Macrotolagus, and Poecilolagus; and the genus Sylvilagus into the 
subgenera Sylvilagus and Microlagus. 

The classification in the present monograph differs from the fore- 
going arrangement in several points. Four instead of five genera are 
recognized, namely, Lepus, Sylvilagus, Brachylagus, and Roinero- 
lagus. The subgenus Pwcilolagus is considered a synonym of the 
subgenus Lepus. Tapeti of Gray, with Limnolagus as a synonym, is 
considered a subgenus of Sylvilagus, and Microlagus becomes a 
synonym of the subgenus Sylvilagus. 

To give subgeneric value to such characters as those shown by 
the species of Pcecilolagus and Microlagus would necessitate the set- 
ting up of a considerable number of additional equally good sub- 
genera. For instance Lepus alleni, the type of Macrotolagus, differs 
in certain strong characters from all the other black-tailed jack 
rabbits, and Lepus campestris has some marked differences from all 
the Arctic hares. In other words, each well-marked species or group 

a Smithsonian Misc. Coll. (quarterly issue), vol. 45, No. 1456, June 15, 1904. 



[no. 29. 

of related species in a genus would require the erection of a subgenus 
for its reception. 

Genus LEPUS Linnaeus. 

(See text figures Nos. 3, 4, and 5.) 
Lepus Linnaeus, Syst. Nat., ed. 10, I, p. 57, 1758. Type Lepus timidus Linn. 
Geographic distribution. — Circumpolar. In North America from 

Fig. 2. — Distribution in North America of rabbits of the genus Lepus. 

the Isthmus of Tehuantepec in southern Mexico to north Greenland 
and the Arctic islands (see fig. 2). 




Generic character's. — Interparietal not distinguishable in adults; 
supraorbital usually more or less broadly wing-like and subtriangular 
in outline (see PI. IV, fig. 2) ; second to fifth cervical vertebrae longer 
than broad and with strong median carination on dorsal surface; 
third to fifth ribs broad, flattened, and fusiform in outline on lower 
half ; ulna much slenderer and more tapering than radius. In addi- 
tion, various other skeletal characters exist. 

This circumpolar group is represented in North America by two 
subgenera, Lepus and Macrotolagus. 

Fig. 3. — First to seventh ribs and dorsal vertebra?: a, Lepus (reduced about four-ninths) ; 
b, Sylvilagus (reduced about one-fifth). 

Subgenus LEPUS Linnaeus. 



Lepus Linn. Same date and type as the genus. 

Pwcilolagus Lyon, Smith. Misc. Coll. (quarterly issue), vol. 45, No. 1456, June 
15, 1904. Type Lepus americanus Erxl. 

Geographic distribution. — Northern part of the United States to 
the Arctic islands and north Greenland (ranging farthest south along 
the Alleghenies, Rocky Mountains, and Sierra Nevada). 

Subgeneric characters. — Skull proportionately short, broad, and 
arched ; supraorbitals usually strongly subtriangular and standing out 

°See Lyon, Smith. Misc. Coll. (quarterly issue), XLV, No. 1456, pp. 3S9-394, 



[ no. 29. 

broadly wing-like with a wide, open notch between the posterior proc- 
ess and the skull; rostrum broad and heavy; zygomatic arch broad 

and heavy (see Pis. IV and V). 

Two annual molts, with distinct 
summer and winter pelages, usually 
strongly contrasted in color. 

Remarks. — Doctor Lyon placed 
the varying hares in a new subgenus, 
Poscilolagus, but after careful exami- 
nation of abundant material the 
writer is unable to find anj^ character 
which distinguishes them more than 
specifically from the Arctic hares. 
The white-tailed jack rabbits (L. 
campestris) are almost exact inter- 
mediates in general proportions and 
appearance between the Arctic hares 
and the black-tailed jack rabbits. 
The skulls of the white-tailed jack 
rabbits are usually very distinct, but 
in some cases, especially in Kansas, are scarcely distinguishable from 
those of the black-tailed species. 

Fig. 4. — Second to fifth cervical verte- 
brae : a, Lepus (natural size) ; 6, 
S yl vilagus ( enlarged ) . 

Subgenus MACROTOLAGTJS Mearns. 

Macrotolagus Mearns, Proc. U. S. Nat. Mus., XVIII, p. 552, June 24, 1896. 
Type Lepus alleni Mearns. 

Geographic distribution. — Mexico and western United States. 

Subgeneric characters. — Ears proportionately very long; legs and 
feet long and slender; skull less arched and proportionately longer 
and narrower, or 
slenderer, than in the 
subgenus Lepus (see 
PL VII, fig. 4) ; ros- 
trum slender ; post- 
orbital process long- 
er and narrower, pos- 
terior tip touching 
skull and inclosing a 
long, narrow foramen in place of a broad, open notch; spines of 
lumbar vertebrae longer. One annual molt. 

Remarks. — The black-tailed jack rabbits belong to the western 
United States and Mexico, and are especially characteristic of the 

Fig. 5.- 

-Ulna and radius : a, Lepus (reduced about one- 
third) ; b, Sylrilagus (natural size). 


desert, interior plains, and tablelands, although in climatically favor- 
able areas they live far beyond these limits. In the southwestern 
United States and northern Mexico, they range entirely across the 
continent. They range south along the east coast from Texas to near 
Tampico; and on the west coast from California to northern Tepic, 
Mexico, and are then absent until they reappear on the shore of the 
Pacific at the Isthmus of Tehuantepec and range thence along the 
coast into the adjoining part of Chiapas. In the interior they have 
an unbroken distribution from southern Idaho to the Isthmus of 

Although most characteristic of open, treeless plains, yet in certain 
regions, as in northern California and elsewhere, they occupy partly 
wooded country and even invade open pine forests. 

This subgenus is made up of two well-defined groups: The cali- 
fornicus or gray-sided group, and the callotis or white-sided group. 
The calif ornicus group, including L. insularis, reaches its greatest 
development north of the Mexican boundary, has its center in the 
Desert Plateau, and ranges from sea to sea along the southern border 
of the United States. The callotis group includes Lepus callotis, L. 
flavigidaris, L. aliamirce, L. gaillardi and subspecies, and L. alleni 
and subspecies. It reaches its greatest development south of the 
Mexican border, and also ranges entirely across the continent. 

L. alleni, the type of the subgenus Macrotolagus, differs strikingly 
from other members of the subgenus in its enormous ears, extremely 
long legs, and a remarkably short and peculiarly colored tail. All 
other members of this long-eared, long-legged subgenus have a general 
similarity in their comparatively shorter ears and legs and their much 
larger, longer, and differently colored tails. 

(See text figures Nos. 3, 4, and 5.) 



Sylvilagus Gray, Ann. and Mag. Nat. Hist., XX, ser. 3, p. 221, 1867. Type, 
Sylvilagus flaridanus mallurus (Thomas). 

Geographic distribution. — Southern Canada to southern South 
America (see fig. 3). 

General characters. — Interparietal distinct in adults; supraorbital 
process narrower and more strap-shaped, or tapering to a slenderer, 
more pointed tip posteriorly than in Lepus; the posterior notch or 
foramen usually much narrower, or even absent, owing to the union 
of the postorbital process along its entire length with the skull ; sec- 


ond to fourth cervical vertebrae broader than long with dorsal surface 
flattened and without carination; anterior ribs of nearly uniform 
width throughout their length, and having a narrow, rod-like form ; 
ulna and radius about equal .in size. One annual molt. (In addi- 
tion various other skeletal characters exist.)" 

Remarks. — There appear to be two recognizable subgenera in this 
group, Sylvilagus and Tapeti. 

Subgenus SYLVILAGUS Gray. 


Sylvilagus Gray. Same date and type as the genus. 

Microlagus Trouessart, Catalogus Mamm., I, fasc. Ill, p. 660, 1897. Type, 
Sylvilagus bachmani cinerascens (Allen). 

Geographic distribution. — North and South America from south- 
ern Canada to an unknown distance in South America. 

Siibgeneric characters. — Skull generally averages proportionately 
lighter and less heavily ossified than in Tapeti (see PL IX) ; rostrum 
slenderer; supraorbitals lighter and less broadly attached to the 
skull; pelage finer and softer; tail larger, more abundantly haired; 
feet usually more heavily haired. 

Remarks. — This subgenus contains all of the species of rabbits 
commonly known as cottontails, and also the small brush rabbits of 
the Pacific coast. 

The brush rabbits represent a well-marked specific type, but I 
fail to find characters of sufficient weight to warrant their subgeneric 
separation from the cottontails, and therefore reject the subgenus 
Microlagus proposed by Trouessart for their reception. The small 
rounded tail of the brush rabbits is the strongest character separating 
them from the common cottontails. The light skull, with narrow 
pointed rostrum and slender postorbital processes, is closely similar 
in general type to the skulls of Sylvilagus nuttalli and of some forms 
of S. auduboni, and differs much less radically from them than does 
the skull of S. transitionalis from that of S. floridanus. 

In North America /Sylvilagus, next to Lepus, is the most wide- 
spread of all the subgenera of hares and rabbits. Its members range 
from coast to coast throughout most of the United States and south 
to Costa Rica. They may be arranged in four well-marked groups, 
which are designated by the names of their most characteristic spe- 
cies, as follows: 

1. /Sylvilagus floridanus group, consisting of S. floridanus and sub- 
species, with the closely related S. robustus, S. cognatus, S. transition- 

°See Lyon, Smith. Misc. Coll. (quarterly issue), XLV, No. 1456, pp. 396-401, 




alls, and S. nuttalli with its subspecies. It inhabits most of the 
United States, Mexico, and parts of Guatemala, Nicaragua, and Costa 
Rica, and ranges along practically all the Atlantic coast from Maine 

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Fig. 6. — Distribution in North America of rabbits of the genus Sylvilagus. 

to Yucatan, but is absent on the Pacific coast, except from the Isthmus 
of Tehuantepec to Chiapas. 

a For convenience S. nuttalli and subspecies are treated as a separate group in 
the text. 


2. S. auduboni group, containing only the subspecies of auduboni. 
This group is western in distribution and ranges along the Pacific 
coast from near San Francisco to central Sinaloa, Mexico, and east 
of the Rocky Mountains to the Great Plains and the Tableland of 

3. S. cunicidarius group comprising the subspecies of cunicularius 
and S. graysoni. The cunicularius group occupies the mountains and 
plains about the southern end of the Mexican Tableland, and thence 
south and west to the Pacific coast, and from southern Sinaloa to 
northwestern Oaxaca. 

4. S. bachmani group, containing S. bachmani and subspecies and 
the closely related S. mansuetus. It is peculiar to a narrow belt on 
the Pacific coast from Oregon to the southern end of the Peninsula 
of Lower California. It does not occur at any point in the Desert 
Plateau area, although its range extends to the western slopes of the 
Sierra Nevada. 

Subgenus TAPETI Gray. 

Hydrolagus Gray, Ann. & Mag. Nat. Hist., ser. 3, XX, p. 221, 1867. Type, 
Sylrilagus aquaticus (Bachman). Antedated by Hydrolagus Gill, 1862, a 
genus of fishes. 

Tapeti Gray, Ann. & Mag. Nat. Hist., ser. 3, XX, p. 224, 1867. Type, Sylvi- 
lagiis bra silicnsis (Linn.). 

Limnolagus Mearns, Science, n. s., V, p. 393, March 5, 1897. A new name for 
Hydrolagus Gray, preoccupied. 

Geographic distribution. — Southeastern United States; also from 
eastern Mexico to northern Patagonia. 

Subgeneric characters. — Externally the members of this group are 
distinguished b}^ their coarse, harsh (and usually rather thin) pelage; 
proportionately small, thinly haired ears; small, short-haired hind 
feet, and small, sometimes almost obsolete, tail. Skull usually more 
heavily ossified than in true SylvUagus; rather narrow; braincase 
depressed ; zygomatic arch comparatively broad and heavy, widest in 
the middle, and of about equal breadth on anterior and posterior 
thirds; anterior foot-like process of zygomatic arch broadly expanded 
and sharply edged ; supraorbital broadly attached to frontals and on 
practically same plane ; anterior notch of supraorbitals nearly or quite 
obsolete, and postorbital process comparatively short and sometimes 
completely fused to skull along entire length, or short and separated 
from skull by a narrow notch, or narrowly strap-shaped and touching 
skull at posterior end, thus inclosing a narrow foramen ; bullae small 
and compactly rounded. (See PL XII.) 

The most salient skull characters, compared with Sylvilagus, are 
the depressed and comparatively narrow braincase; decurved rostrum ; 


flattened and broadly attached supraorbital; and heavy zygomatic 
arch with broadly expanded sharp-edged anterior process. 

Remarks. — In 1901 Thomas definitely fixed the names Lepus brasil- 
iensis Linn, and L. tapeti Pallas on the small rabbit living near Rio 
Janeiro, Brazil. He described Sylvilagus brasiliensis as a very small 
species, giving the basilar length of an adult skull from Rio as 47 mm., 
and stating that in this specimen the postorbital process is firmly 
welded to the skull postorbitalty. Gray based his Tapeti on Lepus 
brasiliensis, and characterized it as follows : " Skull like Lepus, but 
the hinder supraorbital notch narrow, the lobes short, with a sharp 
inner edge ; the front of the lower edge of the zygoma dilated, sharp- 
edged, porous above ; hinder nasal opening rather narrow. Tail none. 
Ears short." As shown by the accompanying photograph (see PL 
XII, figs. 1, 4) the skull characters given by Gray apply accurately to 
a specimen in the U. S. National Museum (No. 113432) from Cha- 
pada, Matto Grosso, central southern Brazil. This no doubt repre- 
sents Sylvilagus minensis Thomas, a close relative of S. brasiliensis, 
which may be taken as typical of the subgenus. Another skull from 
the same locality has a narrow strap-shaped postorbital which touches 
the skull at the posterior end and incloses a narrow foramen. This 
character varies considerably also in other species of this group in 
North and South America, but the supraorbital in Tapeti is broadly 
attached to the skull, the anterior notch much reduced or absent, and 
the posterior process and notch usually proportionately short. The 
external tail is nearly obsolete in some South American species, and 
is proportionately small in all members of the subgenus. The strik- 
ing general similarity in form of skull, in size of feet, ears, and tail, 
and in the character of the coarse, harsh pelage, of the half dozen 
species of rabbits examined from widely separated countries of South 
America, the gabbi group of Central America, and the swamp rabbits 
of the United States, is so marked that it is evident they form a closely 
related group. The swamp rabbit differs from the rest of the group 
in having the posterior process of the supraorbital more closely united 
to the skull along its inner border, and in much heavier claws, but 
in view of the strong resemblances in other respects these differences 
appear to be insufficient to warrant distinguishing the animals sub- 
generically from Tapeti, with which obviously they are closely allied. 
Most of the South American species I have had the opportunity to 
examine belong to this group. 

Tapeti is the only American subgenus not represented within the 
borders of the Desert Plateau area. The Mexican and Central Amer- 
ican representatives of the gabbi group inhabit dense forest under- 
growth, and in this respect their habits resemble those of their 
forest-loving relatives, the swamp rabbits. The range of the latter 

"Ann. and Mag. Nat. Hist., VIII, p. 535, 1901. 


in the southeastern United States is separated from the northern 
limit of JS. gabbi truei, in east Mexico, by the arid treeless area which 
occupies the coastal region of southern Texas and Tamaulipas. This 
group (Tapeti) probably originated far to the south, and ancestors 
of the swamp rabbits of the United States, after pushing northward 
along the coastal belt, were isolated from the main body of the group 
by a change of climatic conditions which brought about the present 
gap in its range. The skull of a Mississippi specimen of aquaticus 
has the postorbital process separated from the frontals by a narrow 
notch, just as in the skull of S. minensis figured on Plate XII. 



Brachylagus Miller, Proc. Biol. Soc. Washington, XIII, p. 157, June 13, 1900. 
Type, Brachylagus idahoensis (Merriam). Monotypic. 

Geographic distribution. — Southern Idaho to central Nevada and 
west to northeastern California and southeastern corner of Oregon. 

Generic characters. — Size small, smallest of American rabbits; 
ears short, broad, and rounded; tail very small, short-haired; two 
annual molts with differently colored pelages. Skull lightly ossified, 
short and very broad posteriorly; posterior prism of second lower 
premolar and of first and second lower molars about half as large as 
anterior prisms ; bullae proportionately extremely large ; rostrum very 
small, short, and pointed; nasals short and broad; bony palate very 
narrow ; supraorbitals attached to frontals by a narrow base ; anterior 
and posterior processes of supraorbitals narrow, slender, and rodlike ; 
tips usually free and truncated, giving ends of processes a curiously 
angular appearance; in old individuals the processes extend front 
and back until their tips join the skull, thus inclosing long slit-like 
and well-defined anterior and posterior foramina of nearly equal 
length; interparietal distinct; radius and ulna, ribs, and cervical 
vertebrae as in Sylvilagus. (See PL XII, figs. 4, 5, 6.) 

Remarks. — The wide braincase with disproportionately large bullae 
and small, short, and tapering rostrum produces a curious superficial 
resemblance between the skulls of idahoensis and those of very young 
black-tailed jack rabbits. The single species of this well-marked 
genus is peculiar to the sagebrush plains of the Great Basin at the 
northern end of the Desert Plateau. 

Genus ROMEROLAGUS Merriam. 


Bomerolagus Merriam, Proc. Biol. Soc. Washington, X, p. 173, December 29, 
1S96. Type Romerolagus nelsoni Merriam. Monotypic. 

Geographic distribution. — Volcanoes of Popocatepetl and Iztacci- 
huatl on slopes facing the Valley of Mexico. 




Generic characters. — Size small, smallest of American rabbits ex- 
cept Brachylagus; ears short and round ; feet short ; external tail 
absent ; form of body and general appearance, including pelage, 
much like a giant tailless Microtus. Clavicle complete, articulating 
with sternum ; skull much like that of Sylvilagus and heavily ossified ; 
bony palate very long ; zygomatic arch very heavy, with posterior end 
of jugal much extended (nearly as in Ochotona) ; anterior groove in 
upper incisors very strong and deep; interorbital breadth narrow; 
supraorbitals broadly attached to frontals, much reduced, and with- 
out anterior notch ; postorbital process very short and divergent, in- 
closing a shallow notch; interparietal distinct; caudal vertebrae nine, 
much reduced in size. Ulna and radius, ribs, and cervical vertebra? 
as in Sylvilagus. One annual molt ( ?). (See PL XIII, figs 1, 2, 3.) 

Remarks. — The only known species of this genus is an extraor- 
dinary little animal with no known near relative, the most aberrant 
member of the American Leporidse. In habits, color, and form it 
resembles a giant field mouse (Microtus), and in distribution is the 
most restricted of all American rabbits, being limited to a small area 
about 10 miles long, high up on the slopes of the two great volcanoes 
on the southeastern border of the Valley of Mexico. 

List of species of North American hares and rabbits, icith type localities. 

ber of 

Type locality. 









Lepus arcticus Ross 

bangsi Rhoads 

canus Preble 

grcenlandicus Rhoads 

othns Merriam. . .'. 

poadromus Merriam 

campestris Bachman 

tovnsendi (Bachman). 

sierrse Merriam 

americanus Erxleben 

struthopus Bangs 

virginianus (Harlan) . 

phseonotus Allen 

bishopi (Allen) 

macfarlani Merriam.. 

dalli Merriam 

columbiensis Rhoads . 

washingtoni Baird 

klamathensis (Mer 

bairdi Hayden 

cascadensis Nelson 

alleni Mearns 

palitans Bangs 

gaillardi Mearns 

battyi Allen 

callotis Wagler 

altamirse( Nelson) 

flavigularis (Wagner) 

californicus Gray 

wallawalla (Merriam) 
richardsoni Bachman 
bennetti (Gray) 

Northern Baffin Land, Arctic America. 

Codroy, Newfoundland. 

Hubbart Point, Hudson Bay, Keewatin, Canada. 

Robertsons Bay, northwestern Greenland. 

St. Michael, Alaska. 

Stepovak Bay, Alaska Peninsula. 

Plains of the Saskatchewan, near Carlton 
House, Saskatchewan. 

Old Fort Wallawalla, Washington. 

Hope Valley, Alpine County, California. 

Fort Severn, southwestern coast Hudson Bay, 

Digby, Nova Scotia. 

Blue Mountains, near Harrisburg, Pennsyl- 

Hallock, Minnesota. 

Turtle Mountains, North Dakota. 

Fort Anderson, Mackenzie, Canada. 

Nulato, Alaska. 

Vernon, British Columbia. 

Fort Steilacoom, Washington. 

Fort Klamath, Oregon. 

Wind River Mountains, Wyoming. 

Near Hope, British Columbia. 

Rillito Station, Arizona. 

Agua Caliente, Sinaloa, Mexico. 

Play as Valley, southwestern New Mexico. 

Northwestern Durango, Mexico. 

Southern end Mexican Tableland. 

Alta Mira, Tamaulipas, Mexico. 

Near Tehuantepec City, Oaxaca, Mexico. 

St. Antoine (near Jolo'n), California. 

Touchet, Washington. 

Near Jolon, California. 

San Diego, California. 


List of species of North American hares and rabbits, with type localities — Cont'd. 


ber of 



Type locality. 




Lepus californicus deserticola (Mearns) 

West edge Colorado Desert, California. 


eremicus (Allen ) 

texianus (Waterhouse) . . 

Fairbanks, Arizona. 


Western Texas. 


melanotis ( Mearns) 

Oklahoma, near Independence, Kansas. 


merriami (Mearns) 

asellus (Miller) 

Fort Clark, Texas. 


San Luis Potosi, Mexico. 

festinus (Nelson) 

Irolo, Hidalgo, Mexico. 


martirensis (Stowell) ... 

San Pedro Martir Mountains, Lower Califor- 
nia, Mexico. 


magdalenee Nelson 

Magdalena Island, Lower California, Mexico. 


Santa Anita, Lower California, Mexico. 


Espiritu Santo Island, Lower California, Mex- 


Near Micco, Florida. 


mallurus (Thomas) .. 

Raleigh, North Carolina. 


mearnsi (Allen ) 

Fort Snelling, Minnesota. 


similis Nelson 

Valentine, Nebraska. 


alacer (Bangs) 

Still well, Oklahoma. 


chapmani (Allen} 

Corpus Christi, Texas. 


holzneri ( Mearns) 

Huachuca Mountains, Arizona. 


subcinetus ( Miller) . . . 

Negrete, Michoacan, Mexico. 


restrictus Nelson 

Zapotlan, Jalisco, Mexico. 


orizabse (Merriam)... 

Mount Orizaba, Puebla, Mexico. 


connectens (Nelson) . 

Ohichicaxtle, Vera Cruz, Mexico. 


russatus (Allen) 

Pasa Nueva, Vera Cruz, Mexico. 


aztecus ( Allen ) 

Tehuantepec City, Oaxaca, Mexico. 


chiapensis (Nelson).. 

San Cristobal, Chiapas, Mexico. 


yucatanicus (Miller). 

Merida, Yucatan, Mexico. 


Manzano Mountains, New Mexico. 


Davis Mountains, Texas. 


transitionalis (Bangs) 

Liberty Hill, Connecticut. 


nuttalli ( Bachman) 

Eastern Oregon. 


grangeri (Allen) 

Hill City, South Dakota. 


pinetis (Allen) 

White Mountains, Arizona. 


auduboni (Baird) 

San Francisco, California. 


San Emigdio, Kern County, California. 


sanctidiegi (Miller)... 

Mexican boundary, near San Diego, California. 


confinis ( Allen) 

Playa Maria Bay, Lower California, Mexico. 


arizonae (Allen) 

Beal Spring, near Kingman, Arizona. 


goldmani (Nelson) 

Sinaloa, Sinaloa, Mexico. 


minor (Mearns) 

cedrophilus Nelson . . . 

El Paso, Texas. 


Cactus Flat, near Cliff, New Mexico. 


warreni Nelson 

Coventry, Colorado. 


baileyi (Merriam) 

Eastern side Big Horn Basin, Wyoming. 


neomexicanus Nelson 

Fort Sumner, New Mexico. 


parvulus (Allen) 

Apam, Hidalgo, Mexico. 


cunicularius (Waterhouse) 

Sacualpam, Mexico. 


pacificus (Nelson) . 

Aeapulco, Guerrero, Mexico. 


insolitus (Allen) . . . 

Plains of Colima, Colima, Mexico. 


graysoni (Allen) 

Tres Marias Islands, western Mexico. 


Between Monterey and Santa Barbara, Cali- 


ubericolor (Miller)... 

Beaverton, Oregon. 


cinerascens (Allen) .. 

San Fernando, California. 


exiguus Nelson 

Yubay, central Lower California, Mexico. 


peninsularis (Allen) . 

Santa Anita, Lower California, Mexico. 


cerrosensis (Allen) . . . 

Cerros Island, Lower California, Mexico. 


mansuetus Nelson 

San Jose Island, Gulf of California, Mexico. 


gabbi (Allen) 

Talamanca, Costa Rica. 


ineitatus ( Bangs) 

San Miguel Island, Panama. 
Mirador, Vera Cruz, Mexico. 


truei (Allen) 


insonus (Nelson) 

Omilteme, Guerrero, Mexico. 


palustris ( Bachman ) 

Coast of South Carolina. 


paludicola (Miller and 
aquaticus (Bachman) 

Fort Island, near Crystal River, Florida. 


Western Alabama. 


littoralis subsp. nov. . . 

Houma, Louisiana. 


Brachvlagus idahoensis (Merriam) 

Pahsimeroi Valley, Idaho. 


Romerolagus nelsoni Merriam 

Mount Popocatepetl, Mexico. 



Genus LEPUS. 

Subgenus LEPUS. 


Ears short arid broad ; length from notch in dried skin averaging from 62 to 
81 mm. ; pelage long and thick. 
Size larger, total length averaging more than 5S0 mm. ; ears from 
notch 75 to SI mm. ; tail long, white at all seasons ; underfur in 
winter white (the Arctic hares). 
Pelage white throughout the year. 

Claws very long and heavy ; incisors long and projecting forward 

(Ellesmere Land and Greenland) grcenlandicus (p. 67) 

Claws not long and heavy ; incisors shorter and strongly decurved 

(northern Baffin Land) arcticus (p. 61) 

Pelage gray or brown in summer. 

Upperparts in summer iron gray. 

Upperparts pale iron gray ; a little more dusky on sides and 
rump than on back (Barren Grounds W. of Hudson 

Bay) canus (p. 65) 

Upperparts dark iron gray ; distinctly more dusky on sides 
and rump than on back. 
Head lighter buffy gray ; ears with much more gray 
and white; bullae larger (Baffin Land and N. 

Ungava) arcticus (p. 61) 

Head darker buffy gray ; ears mainly black ; bulla? 
smaller (Newfoundland and coast of Labra- 
dor) bangsi (p. 64) 

Upperparts in summer dusky brown. 

Upperparts blackish brown; skull and feet very large (W. 

coast of N. Alaska) othns (p. 69) 

Upperparts cinnamon brown; skull nearly as in othus; feet 

much smaller (Peninsula of Alaska) poadromus (p. 71) 

Size smaller, total length averaging less than 520 mm. ; ears from notch 
62 to 70 mm. ; tail short, buffy brown or dusky in summer ; underfur 
in winter strongly tipped with zone of buffy (varying hares and 
snowshoe rabbits). 
Tops of hind feet in brown pelage similar to sides of body, or a little 
brighter, sometimes mixed with white. 
Total length averaging less than 450 mm. ; in brown pelage under- 
side of hind toes white or whitish, contrasting with dusky 
Upperparts dusky yellowish brown ; contrast between under- 
side of toes and sole not very strong but distinct (inte- 
rior of British Columbia) columbiaisis (p. 102) 

S5595— No. 29—09 4 49 


Upperparts more of a dusky reddish brown shade. 

Upperparts throughout the year dusky russet brown; con- 
trast between white toes and dusky sole strong 
(coast of Washington and British Columbia). 

washingtoni (p. 105) 

"Upperparts in summer dusky fawn color, in winter white; 

contrast between whitish toes and dusky sole not 

striking but distinct (mountains of Oregon and 

northeastern California) klamathensis (p. 107) 

Total length averaging more than 450 mm. ; in brown pelage under- 
side of toes like soles. 
Total length averaging more than 500 mm. ; color in summer 
bright rusty brown; tops of hind feet brighter rusty 

than body (Virginia to Maine) virginianus (p. 92) 

Total length averaging less than 500 mm. ; color in summer 
duller and less rusty ; tops of hind feet dull buffy or 
dull rusty mixed with some whitish. 
Upperparts in summer dusky gray. 

Tops of hind feet mixed rusty ochraceous and white; 
skull very short and broad (Turtle Mountains, 

North Dakota) bishopi (p. 97) 

Tops of hind feet mixed dull buffy brown and whitish ; 
skull long and narrow (some specimens from 
Nova Scotia, Magdalen Islands, and Newfound- 
land) struthopus (p. 90) 

Upperparts in summer dull rusty brownish or rather pale 
dingy rusty or dingy yellowish buffy. 
Upperparts in summer dark rusty brownish (eastern 
Maine, New Brunswick, and Nova Scotia ) . 

strutliopus (p. 90) 

Upperparts in summer light rusty brownish or pale 

dingy yellowish buffy (Wisconsin to southern 

border of Manitoba) phceonotus (p. 95) 

Tops of hind feet in summer pelage white. 

Upperparts in summer dingy yellowish buffy (Lower Yukon re- 
gion, Alaska) dalU (p. 100) 

Upperparts in summer dusky gray, dusky, or dusky reddish. 

Upperparts dusky gray or dusky yellowish gray ; head paler, 
more buffy than body ; rump about like back. 
Size smaller ; skull light and slender, basilar length 
averaging about 59 mm. (south Mackenzie and 
Keewatin to north shore Lake Superior). 

amrrieanus (p. S7) 
Size larger ; skull large and heavy, basilar length averaging 
about 63 mm. (Alaska from Lake Clark east, and 
Canada from middle Mackenzie north). 

niacfarlani (p. 98) 

Upperparts dusky or dusky reddish ; head distinctly more 

fulvous than body ; rump more blackish. 

Upperparts dusky grizzled with dingy gray ; rump and 

upperside of tail blackish (Rocky Mountains from 

Montana to New Mexico) bairdi (p. 100) 


Upperparts dusky reddish. 

Upperparts a lighter shade of dull or dusky reddish; 
ciuuauion of head lighter; black on rump and 
top of tail not so heavy (Rocky Mountains, 

Montana to New Mexico) bairdi (p. 109) 

Upperparts darker dusky reddish ; cinnamon of head 
darker ; black on rump and top of tail much 
heavier (Cascade Mountains of British Colum- 
bia and Oregon) cascadensis (p. 112) 

Ears long and comparatively narrow, length from notch in dried skin averag- 
ing from 95 to 144 mm. 
Tail always white, or white with a narrow dusky line along middle of 
upper side, but not extending up on rump ; winter pelage white or 
much paler than summer (white-tailed jack rabbits). 
Summer pelage yellowish gray; tail pure white (east of the Rocky 
Mountains, Saskatchewan to Kansas and Colorado). 

rampestris (p. 74) 
Summer pelage dark gray ; tail white, usually more or less dusky along 
middle of upper side. 
Smaller; hind foot averaging less than 150 mm. (Washington to 

SW. Colorado) toicnsendi (p. 78) 

Larger ; hind foot averaging more than 150 mm. ( Sierra Nevada, 
California) sicrrcc (p. 82) 



Tail never entirely white; always with a distinct black line along top and on 
median line of rump; winter pelage similar to that of summer (black- 
tailed jack rabbits). 
Flanks white or pale gray, similar to abdomen and sharply contrasted with 
back ; ears without trace of black patch at tip. 
Nape more or less black. 

Nape with black not divided (south central Mexico). 

callotis (p. 122) 
Nape with black divided into two lateral stripes by median stripe 
of buff. 
Back ochraceous buff (south coast Oaxaca and Chiapas). 

flavigularis (p. 125) 
Back more grayish, cream buff (southern Tamaulipas). 

aUamirce (p. 124) 
Nape gray or grayish buff. 

Size very large, ear enormous, tail very small, sides of body and 
rump iron gray. 
Back dull cream buff (S. Arizona and N. Sonora). 

aUrni (p. 117) 
Back rich cream or pinkish buff (S. Sonora and Sinaloa). 

palitans (p. 118) 
Size small, ears and tail medium, flanks white, rump iron gray. 
Size larger (over 500 mm.) ; back buffy fawn color (SW. New 

Mexico and W. Chihuahua) gaiUardi (p. 120) 

Size smaller (under 500 mm.) ; back and head paler (NW. 
Durango) battyi (p. 121) 


Flanks similar to back, or slightly paler; ears with distinct black patch 
at tip. 
Nape with more or less black. 

Back black or blackish (Espiritn Santo Island, Lower Cali- 
fornia) insularis (p. 150) 

Back dark gray or dark buffy gray. 

Ears smaller, averaging from notch less than 115 mm. (S. 

Texas and NE. Mexico) merriami (p. 148) 

Ears larger, averaging from notch more than 115 mm. (San 

Luis Potosi, etc.) asellus (p. 150) 

Nape gray, dull buffy, or buffy brown. 

Rump and adjoining parts of hind legs gray, forming distinctly 
paler rump patch contrasting with back and sides. 
Back and sides pale grayish (Chihuahua and Texas north 

to western Colorado) texianus (p. 142) 

Back and sides dark, buffy brown or ochraceous buffy. 

Back and sides bright ochraceous buffy (Great Plains, 

NW. Texas to Nebraska) mclanotis (p. 140) 

Back and sides dark buffy brown, or grayish buffy brown. 
Back and sides dark buffy brown ; nape dark brown- 
ish buffy; size larger; ears short, averaging 
less than 112 mm. from notch (Gulf coast, 

Texas merriami (p. 148) 

Back and sides dull grayish buffy brown ; nape gray- 
ish buffy; size smaller; ears long, averaging 
129 mm. from notch (S. end Mexican Table- 
land) festinus (p. 151) 

Bump and adjoining parts of hind legs similar to back and sides, 
no rump patch. 
Upperparts dark, varying from buffy brown to dull buffy. 
Head and ears colored like body. 

Size larger, upperparts rich fulvous brown (coast 
region middle California, Sacramento Val- 

ley) calif amicus (p. 129) 

Size smaller, upperparts duller, more grayish fulvous 
brown (coast region southern California and 

NW. Lower California) bennctti (p. 130) 

Head and ears grayer than body. 

Ears longer, averaging from notch 110 mm. : 
darker gray (Cape Region. Lower Cali- 
fornia) xanti (p. 155) 

Ears shorter, averaging from notch 99 mm. ; paler 
gray (Margarita and Magdalena Islands. 

Lower California) magdalenw (p. 154) 

Upperparts pale, varying from gray to pale yellowish buff or 
pale dull grayish buff. 
Upperparts buffy or dull grayish buff. 

Upperparts pale yellowish or sandy buffy (San 
Joaquin Valley, California )-rich a rdsoni (p. 133) 
Upperparts dull grayish, slightly pinkish buffy ( south- 
ern Arizona and N. Sonora) eremicus (p. 140) 


Upperparts gray or with bufliness when present reduced to a 
slight tinge. 
Head and ears grayer than body (central Lower Cali- 
fornia) martirensis (p. 152) 

Head and ears similar to body. 

Upperparts paler, dull ashy gray or pale slightly 
huffy gray (Colorado Desert and north to 

Utah) deserticola (p. 137) 

Upperparts darker, slightly pinkish dark iron gray (NE. 
California to Washington) .wallawalla (p. 132) 



Tail comparatively large and loosely Haired, with underside always conspicu- 
ously cottony white; feet well haired (the cottontails). 
Size large, largest of the cottontails, nearly equaling the jack rabbits; 
length averaging 480 to 511 mm. ; pelage coarse and harsh ( south- 
ern and western Mexico). 
Upperparts brownish gray; hind legs and side of hind feet rusty 
brownish ; tops of hind feet rusty or dull buffy. 
Larger (average length 511 mm.) ; ears longer (averaging from 
notch 74.4 mm.) (S. end Mexican Tableland). 

cunicularius (p. 239) 
Smaller (average length 4S9 mm.) ; ears shorter (averaging from 
notch 70.7 mm.) (coast of Guerrero, Mexico). 

paciflcus (p. 242) 

Upperparts deep buffy brownish or reddish brown; sides of hind legs 

and feet bright rusty reddish; tops of hind feet clear white or 

whitish, in sharp contrast. 

Larger (average 500 mm.) ; ears longer (averaging from notch 

70.4 mm.) (coast of Michoacan to Sinaloa, Mexico). 

insolitus (p. 243) 
Smaller (average length 4S0 mm.) ; ears shorter (averaging from 
notch 57 mm.) (Tres Marias I., W. Mexico). 

graysoni (p. 244) 
Size medium or small; total length averaging from about 350 to 463 mm. 
Bulhe proportionately small with surface smoothly rounded or polished ; 
ears usually comparatively short. 
Rostrum proportionately heavy, broad and strongly angled on 
upper half of base, usually broad and flattened, or decurved, 
near tip; except iu transitionalis, supraorbitals broad and 
heavy and usually ankylosed to skull at posterior end. 
Supraorbitals very small, posterior process short, tapering 
posteriorly to a slender point, free from or barely touch- 
ing skull and anteriorly narrowing until anterior proc- 
ess and notch usually entirely absent or obsolescent 
(Brasstown Bald Mt, N. Georgia, to SW. Maine). 

transitionalis (p. 195) 
Supraorbitals broadly developed; posterior process usually 
broadly strap-shaped and coalescing with skull poste- 
riorly and sometimes along entire length ; anterior proc- 
ess broad and commonly extended to nearly close ante- 
rior notch with squared tip. 


Upperparts of body strongly grayish, varying from light 

to dark ; always with a tinge of buffy, but general 

effect gray. 

Upperparts of body pale buffy grayish ; tops of hind 

feet whitish, with sides of hind feet and back 

of hind legs pale rusty, strongest on legs. 

Small, total length averaging about 408 mm. ; 

ears short, averaging from notch about 50 

mm. (Great Plains from SW. Minnesota to 

near Denver, Colorado) similis (p. 172) 

Large, total length averaging from 425 to 451 

mm. ; ears long, averaging from notch about 

62 to 68 mm. 

Smaller, total length averaging about 425 

mm. ; ear from notch about 62 mm. 

(mountains S.Arizona and W. Mexico). 

hoisneri (p. 178) 

Larger, total length averaging more than 450 

mm. ; ears from notch about 67 mm. 

Bullae larger, averaging in diameter 

about 12 mm. (mountains SW. 

Texas) rohustus (p. 194) 

Bulla? smaller, averaging in diameter 
about 10.7 mm. (mountains central 

New Mexico) cognatus (p. 191) 

Upperparts of body dark grayish with a slight tinge 

of buffy ; tops of hind feet whitish or pale rusty 

with sides of feet deep rusty or reddish brown 

and back of hind legs chestnut or dark rusty. 

Back of hind legs dark chestnut ; ear shorter, 

averaging from notch about 49 mm. ; bulla? 

smaller (S. Texas and NE. Mexico). 

chcipmani (p. 176) 

Back of hind legs brighter, more rusty rufous; 

ears longer, averaging from notch 57 to 59 

mm. ; bulla? larger. 

Size smaller, total length averaging 375 mm. ; 

darker gray (mountains and valleys 

S. end Mexican Tableland). 

orizabce (p. 183) 
Size larger, total length averaging from 400 
to 422 mm. ; paler gray. 
Smaller, total length averaging 400 mm. ; 
bulla? larger; upperparts of body 
grayer and legs and feet paler 
(plains SE. border Mexican Table- 
land) subcinctus (p. 180) 

Larger, total length averaging 422 nun. : 
bulla? smaller; upperparts of body, 
hind legs, and feet darker and more 
rusty rufous rest rictus (p. 181) 


Upperparts of body strongly rusty reddish or rusty buffy, 
varying in intensity but always reddish in general 
Size large, average total length more than 460 mm. ; 
skull large and massive, basilar length about 
59 mm. 
Upperparts darker ; back and hind legs darker 
rufous ; interorbital breadth narrower ; 
bulla? smaller, diameter averaging less than 
10 mm. (Chiapas and Guatemala). 

chiapensis (p. 1S9) 

Upperparts paler ; back of hind legs paler rufous ; 

interorbital breadth wider ; bulla? larger, 

diameter averaging over 11 mm. (Cam- 

peche and Yucatan) yucatanicus (p. 190) 

Size medium or small ; total length averaging from 

416 to 446 mm. 

Size smaller; total length averaging less than 

420 mm. ; ears shorter, averaging from 

notch 50 to 52 mm. 

Upperparts deep pinkish or rusty buffy ; 

skull lighter and slenderer ; diameter 

of bullae about 10 mm. (Oklahoma to 

Alabama) alacer (p. 174) 

Upperparts suffused with a deeper tinge of 
dull rusty; skull heavier, especially 
base of rostrum ; diameter of bulla? 
about 11 mm. (S. Vera Cruz, 

Mexico) russatus (p. 1S6) 

Size larger, total length averaging from 434 to 
446 mm. ; ears longer, averaging from 
notch 54 to 58 mm. 
Tops of hind feet and front line of hind legs 
clear bright white, strongly contrast- 
ing with rufous on hind legs and sides 
of feet. 
Back of hind legs rich bright rufous ; top 
of back brighter more pinkish 
buffy ; diameter of bulla? smaller, 
averaging less than 10 mm. (S. 
coast Oaxaca, Mexico). 

aztecus (p. 187) 
Back of hind legs dull dark rufous ; top 
of back duller buffy; diameter of 
bulla? greater, averaging nearly 11 
mm. (S. Tamaulipas to central 
Vera Cruz, Mexico). 

connectens (p. 1S5) 

Tops of hind feet and front line of hind legs 

not clear bright white, usually more or 

less strongly shaded with rusty or 



Size smaller; back more brownish : 
back of hind legs dark brown- 
ish or chestnut rufous (Florida). 
floridanus (p. 1G4) 
Size larger; back more pinkish buffy; 
back of hind legs paler and more 
rusty rufous. 
Ears longer, averaging from notch 
58 mm. ; upperparts darker, 
more rusty reddish (eastern 
U. S., N. Florida to E. New 

York) mall urns (p. 16G) 

Ears shorter, averaging from notch 
54 mm. ; upperparts paler, 
more pinkish buffy (northern 
IT. S. from W. New York to 

Iowa) mearnsi (pi 169) 

Rostrum proportionately long and slender, narrow and not strongly 
angled on upper half of base ; outlines straight ; narrow 
and rounded at tip; supraorbitals always light and slender, 
tapering to a narrow point nearly or slightly free from 
skull posteriorly, and inclosing a long narrow foramen or 
slit-like notch. 
Ears longer, averaging from notch over GO mm. 

Rostrum long: supraorbitals heavy; postorbitals long; 
braincase broad; size large; total length averages 
386 mm. (mountains from Arizona to Colorado). 

pinetis (p. 207) 
Ears shorter, averaging from notch less than 56 mm. 

Size smaller, total length averaging 352 mm.; bullne 
smaller; gray rump patch not distinct (Washing- 
ton and Oregon to W. Idaho) nuttalli (p. 201) 

Size larger: total length averaging 385 mm.; bullae 
larger; gray rump patch more strongly marked (S. 
Dakota to Idaho and SE. California). 

grangeri (p. 204) 
Bulla? proportionately large with surface irregularly rounded and 
slightly roughened; ears comparatively long (western TJ. S. 
and central and NW. Mexico). 
Upperparts dull dark yellowish buffy, or dark iron gray with a 
slight buffy tinge. 
Upperparts clear dark buffy gray, heavily washed with 
blackish and strongly contrasting with color on back 
Of hind legs. 
Back of hind legs deep rich rufous or rufous brown ; 
rump patch scarcely visible (Sonora and Sinaloa, 

Mexico) goldmani (p. 225) 

Back of hind legs dull brownish ; gray rump patch well 

marked (Lower California) confinis (p. 220) 

Upperparts dull buffy gray, not heavily washed with black 
and not strongly contrasting with color on back of 
hind legs. 


Upper-parts dark, rather yellowish, creamy bnffy; back of 
hind legs dull rusty brown ; rump patch fairly well 
marked; nape light rufous (NE. Arizona to SW. 

Colorado) wurrcni (p, 231) 

Upperparts dull yellowish or brownish buffy; back of hind 

legs dull dark brown with scarcely a trace of rusty; 

rump patch usually absent ; nape dark rufous. 

Size larger, total length averaging 41S mm. ; color 

darker; rump patch absent; ears shorter (coast 

middle California and Sacramento Valley). 

auduboni (p. 214) 

Size smaller, total length averaging 398 mm. ; ears 

longer ; rump patch present, not strongly marked 

(coast S. California and NW. Lower California). 

sanctidiegi (p. 21S) 
Upperparts light yellowish buffy gray or pale gray with a slight 
tinge of buffy. 
Size large, total length averaging from 402 to 411 mm. 

Upperparts yellowish buffy distinctly darkened by over- 
lying black wash; gray rump patch present; back 
of hind legs buffy brownish; skull larger; bullae 
averaging less than 12 mm. (San Joaquin Valley, 

California) vallicola (p. 216) 

Upperparts pale creamy buffy, scarcely or slightly dark- 
ened by overlying black wash ; rump patch obso- 
lete; back of hind legs pale rusty; bullae averaging 
moi-e than 12 mm. (Montana to Colorado). 

bailctji (p. 232) 
Size small, total length averaging from 351 to 375 mm. 

Ears shorter, averaging from notch 55 to 57 mm. ; upper- 
parts darker, more buffy. 
Upperparts dingy, slightly yellowish gray; back of 
hind legs rusty brown (S. Texas to Puebla, 

Mexico, on Tableland) parvulus (p. 236) 

Upperparts light, slightly rusty, yellowish gray; back 
of hind legs brighter rusty (W. Texas and E. 

New Mexico) iicoiiic-ricaints (p. 234) 

Ears longer, averaging from notch 59 to 68 mm. ; upper- 
parts paler, more grayish. 
Ears very large, averaging from notch 68 mm.; 
average diameter of bulla? more than 13 mm. 
(Arizona and SE. California )^arizonce (p. 222) 
Ears shorter, averaging from notch 59 to 60 mm.; 
average diameter of bulla? less than 12.5 mm. 
Upperparts pale sandy gi-ayish; back of hind legs 
dull rusty brown ; underside of neck deep, 
dull buffy; size smaller; skull lighter (S. 
New Mexico, W. Texas, and Chihuahua). 

minor (p. 226) 
Upperparts darker, more creamy buffy ; back of 
hind legs and feet more rusty : underside 
of neck ochraceous buffy ; size larger ; skull 
heavier (mountains western central New 
Mexico and E. Arizona). 

cedrophilus (p. 229) 


Tail small, short, and densely haired, or slender and thinly haired ; underside 
of tail white, gray, or huffy ; large species, total length exceeding 500 mm. 
and hind claws large and exposed; or small species with total length less 
than 400 mm. and hind claws small and concealed. 
Underside of tail white. 

Small, total length less than 400 mm. ; tail small and round with short 
dense hair (brush rabbits). 
Upperparts more or less strongly reddish brown. 

Upperparts dark reddish brown ; ears short ; skull very heavy ; 
rostrum comparatively broad and heavy ; bullae very 
small (coast region NW. California to Oregon). 

ubericolor (p. 250) 
Upperparts dark buffy brown with a reddish suffusion ; ears 
medium; skull light; rostrum light and pointed; bullae 
medium (coast region middle California). 

bachmani (p. 247) 
Upperparts grayish or grayish brown. 
Rump similar to rest of back. 

Upperparts pale buffy gray; ears paler than back; back 
of hind legs rusty (Cape Region, Lower Califor- 
nia) peninsularis (p. 255) 

Upperparts dark grayish buffy brown. 

Back of hind legs grayish brown like sides of body 

(Cerros I.) cerrosensis (p. 255) 

Back of hind legs russet brown (coast region S. Cali- 
fornia and N. Lower California). 

cincrascens (p. 252) 
Rump grayer than back, forming a pale rump patch. 

Upperparts grayish buffy ; rump patch dark iron gray ; 
ears clearer gray than back (central Lower Cali- 
fornia) exiguus (p. 254) 

Upperparts pale dingy buffy grayish ; rump patch dingy 
gray; ears like back (San Jose I., Lower Cali- 
fornia) mansuetus (p. 256) 

Large, total length more than 500 mm. ; tail comparatively slender, 
thinly haired (swamp rabbits). 
Upperparts darker and more rusty brown, especially on hind legs 
(narrow coast belt E. Texas to Mississippi). 

littoralis (p. 273) 

Upperparts paler or more grayish brown, especially on rump and 

hind legs (middle Texas to Oklahoma, and east to S. Illinois 

and Alabama) aquaticus (p. 270) 

Underside of tail dingy gray or buffy. 

Tops of hind feet whitish ; ears from notch about 60 mm. (mountains 

of Guerrero, Mexico) insonus (p. 264) 

Tops of hind feet strongly ochraceous or reddish ; ears from notch less 
than 50 mm. 
Tops of hind feet and legs dark reddish ; hind feet thinly haired ; 
hind claws very large and exposed (swamp rabbits). 
Ear longer, averaging from notch about 52 mm. ; upperparts 
paler, more grayish (N. Florida to Virginia). 

palustris (p. 266) 

Ear shorter, averaging from notch about 45 mm. ; upperparts 

darker, more reddish (S. Florida) pahtdicola (p. 269) 


Tops of hind feet and less bright rusty ocliraeeous ; hind feet more 
thickly haired; hind claws small and concealed (tropical 
wood rabbits). 
Size larger, total length about 420 mm. ( San Miguel I., 

Panama) incitatus (p. 201) 

Size smaller; average total length less than 300 mm. 

Top of head and nape brighter reddish ; ears shorter ; 
skull lighter and slenderer (Honduras to Tanama). 

gabU (p. 259) 

Top of head and nape duller reddish; ears longer; skull 

heavier (Mexico to Guatemala) truei (p. 202) 


Tail absent or almost rudimentary; smallest of American rabbits; total length 
less than 325 mm. 
Tail absent; ears very short; general appearance Microns-like (volcanoes 

on east side Valley of Mexico) Bomerolagus nelsoni (p. 279) 

Tail extremely short, nearly unicolor ; ears longer ; general appearance more 
like the cottontails (Nevada, Idaho, NE. California, and SE. Oregon). 

Brachylagus idahoensis (p. 275) 

Genus LEPUS Linn. 



The Arctic hares of North America are representatives of a well- 
known circumpolar group. The American species L. areticus, L. a. 
bangsi^ L. a. canus, L. gramlandicus, L. othus, and L. poadromus are 
characterized by large size and strictly Arctic distribution (see fig. 7). 
Throughout most of their range they summer north of the tree limit, 
but in winter sometimes penetrate a hundred miles or more into 
the northern border of the timber. In winter they reach Fort York, 
Keewatin, Fort Rae, Mackenzie, and points in the interior of Ungava. 
They are resident in Newfoundland, where they inhabit open hilltops 
and barrens in more or less forested country. 

In Alaska their summer home is on the open tundras of the coast 
and along the west shore south to the Peninsula of Alaska. In win- 
ter they penetrate the partly wooded interior about as far as Nulato. 
On the east side of the continent they range south to Great Whale 
River on the east shore of Hudson Bay and along the coast of Labra- 
dor to the straits of Belle Isle and across into Newfoundland, where 
the group reaches its southern limit. To the north they inhabit all 
the Arctic islands and the coast of Greenland to the extreme northern 
limit, beyond 83° north latitude. The northernmost species, grcvn- 
landieus, is one of the largest, while the southern representative, 
bangs?, is the smallest of the group. All the species have two annual 
molts. The winter pelage is always snowy white, including the un- 
derfill", except small black tips to the ears. The summer pelage is 
gray or brown, except in the case of arcticiis and grmnlandicux. 



[ no. 29. 

Arcticus in the southern parts of its range has the usual gray summer 
pelage, but in the northern part of Baffin Land its summer pelage is 
white, almost as in winter. L. groenlandicus has the two regular 
molts, but remains white throughout the year. It is the most differ- 
entiated of the American species, owing to its remarkably projecting 
incisors and large claws. 

-— £./)/fcr/cus 

= l./tPCT/C(/S BANGS/ 


= /. PO/tO/?OMl/S 

= I. C4MP£S7~f?/S 

= / C/?AfP£<Sr/?/S 7OW/VSSN0/ 

— /. C/f/VPSST/t/S steff.fyik 

Fig. 7. — Distribution of Lepus arcticus and L. campestris and allied forms. 

Arctic hares swim freely across the small streams which in spring 
traverse the Arctic barrens in all directions. L. arcticus, including 
its subspecies, has the widest distribution of any American species. 
L. othus and L. poad/nom us, of the tundras of western Alaska, are re- 
stricted to a narrow coast belt, and in summer are the darkest of the 
species. In summer pelage the Arctic hares are darker on the sides 




of the body and rump than on toji of the back. This is a reversal of 
the distribution of color in cottontails and jack rabbits, in which the 
sides of the body and rump are commonly distinctly paler than the 
top of the back. While this darkening- of the rump and sides appears 
to be opposed to the law of protective coloration, the color scheme may 
be satisfactorily explained by peculiarities of environment. 

Average measurements in the Lepus arcticus group. 






* r s . 





n C 


eadth of r 
B.bove premo 

pth of rostr 
ront of prcrri( 


Origin of specimens 














B o 




























1— ( 



Lepus arcticus 







27. 6 



12. 3 

Northern Ungava. 

Lepus arcticus bangsi ... 

5 596 



73. 7 39. 9 

26. 3 22. 3 

31.0 34.011.3 


Lepus arcticus canus 

2 ... 



75.4 37.7 

26.7 23.4 

31. 6 34. 5,12. 2 

Barrens west of Hudsou 

Lepus gr< enlandicus 

5 664 

73 146 75 

78.0 40.0 

27.7 23.8 


Northwest Greenland and 

Lepus othus 




79. 5 41. 1 28. 6 25. 8 

34.4 34.112.0 

St. Michael and Nulato, 

Lepus poadromus 

(6) 600 

53 147 


76.539.5 26.524.5 

I 1 1 

32. 6 34. 4 12. 


Alaska Peninsula. 

° Three skins ; 5 skulls. 

6 One skin ; 5 skulls. 


American Arctic Hare. 

(PI. IV, fig. 2; PI. V, fig. 2.) 

Lepus arcticus Ross, Voyage of Discovery, ed. 2, II, Appendix IV, p. 151, 1819. 
Type from latitude 73° 37' in northern Baffin Land, southeast of Cape 
Boweu ; collected by John Leach. 

Lepus glacialis Leach, in Ross's Voy. Discovery, ed. 2, II, Appendix IV, p. 170, 
1S19. Same type and locality as arcticus. 

Lepus laoradorius Miller, Proc. Biol. Soc. Washington, XIII, pp. 39-40. May 29, 
1899. Cotypes from Fort Chiino, Ungava, Canada, skull 23132 and skin 
14119, adults, U. S. National Museum ; collected by L. M. Turner, Sep- 
tember 28, 1S82. 

Geographic distribution,. — Baffin Land, and probably adjoining 
islands t© the west ; extreme north coast of Hudson Bay and south 
across Hudson Strait to include most of Ungava to Great Whale 
Eiver on the east shore of Hudson Bay, and Labrador north of Ham- 
ilton Inlet. Vertical range from sea level to an undetermined alti- 
tude ; zonal range, Arctic. 

General characters. — In winter white, except small black tips to 
ears ; in most of Baffin Land whitish in summer also, but in this con- 
dition always distinguishable from gromlandicus by smaller size and 


much smaller and slenderer claws; in southern Baffin Land and 
Ungava in summer upperparts of head and body change to dull buffy 
gray; ears blackish in front and white behind, with subterminal whit- 
ish band isolating a black tip. 

Color in summer pelage {Ungava and southern Baffin Land). — 
Top and sides of head always paler than body, varying from dull 
grizzled silvery gray, with a faint tinge of dull buffy. to a dull griz- 
zled buffy gray ; the buffy clearest, less grizzled with gray, on top of 
nose and sides of head ; upperparts of neck and body dull, rather 
dark, iron gray; underfur tinged with dull brownish buffy; upper- 
parts of body grizzled with dull silvery gray, the grizzling most 
abundant on top of back; sides of body darker and less grizzled with 
silvery gray than back; rump still darker and less grizzled, form- 
ing a poorly marked dusky rump patch; nape similar to top of back; 
tail entirely white; ears on front of outer half blackish, or on basal 
two-thirds dusky grizzled gray; posterior half whitish (or blackish 
at base and whitish on most of terminal part, except tip) ; a whitish 
band across front of outer part near tip, thus isolating the small 
black tip ; posterior border of ear strongly edged with white ; tops of 
fore feet white ; outside of fore legs dusky like flanks ; hind feet white, 
sometimes thinly grizzled with dusky hairs ; outside of hind legs like 
rump; underside of neck dusky smoky gray and, like lower border 
of flanks, only slightly grizzled w T ith gray ; rest of underparts white. 

Color in summer pelage in northern part of Baffin Land. — Entirely 
dull whitish except black tips to ears. 

Color in winter pelage. — Entirely pure white except small black 
tips to ears. 

Skull (Ungava specimens). — Strong and massive; rostrum broad, 
deep, and heavy, slightly tapering; nasals broad, heavy, slightly 
arched ; frontal area strongly depressed with a hump-like swelling on 
crown immediately back of depression; supraorbital process rather 
small and irregularly rounded-triangular in form, standing high 
above plane of frontals and projecting wing-like from skull; the pos- 
terior end of postorbital processes forming blunt points, which reach 
a bony process on squamosals only in very old, much ossified speci- 
mens; anterior notch broad and deep and irregular in form; posterior 
notch very broad and ovate; top of braincase depressed, with median 
and lateral ridges developed enough to give it an indistinctly angular 
form ; premaxillaries forming a shorter, stouter mandible compared 
with that of groznlandicus ; the short, strong incisors abruptly down- 
curving; molar series broad and heavy; incisive foramina very broad 
posteriorly ; postpalatal fossa broad and deep ; bullae comparatively 
small and flattened below, giving an oblong form transverse to axis 
of skull, and strongly embedded in bony tissue; upper outline of skull 


giving a double arch, one in front of and one behind depressed frontal 

The only available skull representing typical arcticus from Baffin 
Land, that of a young adult belonging with the skin of the head and 
neck described below, is not sufficiently developed to afford good 
characters. It is closely like the series from Ungava in the compara- 
tively narrow jugal and the comparatively short upper mandible, 
with short and abruptly down-curving upper incisors; bulla? smaller 
and more deeply embedded in surrounding bony tissue than in the 
Ungava specimens or in grwnlandicus. 

Remarks. — From the available material I can find no characters by 
which to separate labradorius from arcticus. Kumlien states that the 
hares on the southern end of Baffin Land commonly remain white all 
summer, but that others become more or less extensively gray on the 
upperparts. A young of the year in first adult pelage from Niantilik 
Harbor, Cumberland Gulf, southern Baffin Land, now in the U. S. 
National Museum, has the head and neck colored as follows: Top 
and sides of head dingy yellowish-buffy gray, becoming dull whitish 
about eyes and dull buffy white on sides of nose; ears glossy black on 
front half of outside and a broad patch of same color on inside near 
posterior border; outside of ears, on posterior half, blackish at base 
and dingy white thence to near tips, where they change to narrow, 
pure white, subterminal bands, which extend as subterminal rings 
around ears and isolate the small jet black tips; posterior border of 
ears edged with pure white; neck smoky, slightty brownish gray, 
finely and rather thinly grizzled over surface with whitish gray. 

There is evidently considerable individual variation in the summer 
coloration of these hares, and two summer specimens from Fort 
Chimb, UngaA-a, differ considerably in the amount of white on the 
back of the ears. A third specimen from Solomon Island, on the 
north coast of Labrador, has a paler (dark ash} 7 ) gray head than 
those from Fort Chimo, with ears glossy black except for a little griz- 
zling of gray near the base in front and on the inside, and a narrow 
white edge along the entire posterior border. In the nearly uniform 
black ears, lacking the subterminal whitish' band, this specimen 
closely approaches bangsi. A specimen shot at Fort Chimo on June 
10 is just changing into summer pelage. The underside of the head, 
ears, underside of body, and rump still retain the white winter coat, 
but the white woolly winter fur has come off the back en masse, leaving 
the half-grown gray summer coat exposed on practically the entire back 
and sides of body. The top and part of the sides of the head are in 
the dingy, grayish buffy summer coat. The subterminal white or 
whitish band isolating the black tips on the ears appears to be a com- 
mon character in arcticus and canus, and is not very uncommon in 


The scarcity of specimens of arcticus and most of its American 
relatives, especially in summer pelage, renders it difficult to determine 
satisfactorily the relationship and distribution of the various forms. 

Total number of specimens examined 16, from: 

Franklin (Canada): Cumberland Island (Baffin Land), 1; Niantilik 

(Cumberland Gulf), 1. 
Ungava (Canada): Fort Chimp, 7; Solomon Island, 1. 
Keewatin (Canada): Cape Fullerton (Hudson Bay), 6. 


Newfoundland Haee. 

Lepus arcticus bangsi Rhoads, Am. Naturalist, XXX, p. 236, March, 1896 
(author's separates published February 20, 1S96). Type from Codroy, 
Newfoundland, No. 3752, $ ad. Museum of Comparative Zoology (Bangs 
collection) ; collected by Ernest Doane, August 3, 1895. 

Geographic distribution. — Newfoundland and probably adjacent 
part of Labrador north to Hamilton Inlet, and extreme eastern Que- 
bec. Vertical range from sea level up to an undetermined altitude; 
zonal range, Arctic. 

General characters. — Much like southern representatives of arcticus, 
but head duller buffy, grizzled with gray; body in full summer pelage 
grizzled smoky gray, but ears mainly glossy black except for a white 
line along posterior border and grizzling of buffy gray on basal third 
in front. 

Color in summer pelage. — Top of head grizzled buffy gray, paler 
than back; sides of head deeper and clearer, usually more fulvous 
buffy about eyes and back to base of ears, the buffy varying in inten- 
sity; back varying from dark iron gray to paler iron gray slightly 
shaded with dull buffy; rump always blackish; underfur dull 
brownish, sometimes slightly tinged with dull cinnamon buffy becom- 
ing paler toward base, and sometimes with a light plumbeous basal 
zone ; sides of body and outside of legs darker and less grizzled with 
gray than back, though not so dark as rump; tops of fore feet plain 
white or grizzled with dusky gray; tail white, sometimes with a 
narrow median line of dusky; ears glossy black with some grizzling 
of gray about base in front and on inside, and a narrow white line 
along posterior border; tw T o out of six specimens have ears entirely 
black except the white line along posterior border ; one other has the 
ears all black except gray border around entire edge and a grizzling 
of same on front and inside; three others have the back of ears on 
posterior half mainly whitish except for broad black tip, the posterior 
border white, and the inside and anterior part of outside, including 
anterior border, grizzled with gray, the gray in one specimen forming 
a subterminal band across front, thus isolating the well-marked 
glossy black tip; neck below and on sides even more blackish than 


lower flanks and like rump much darker than back; this blackish 
becomes darkest on underside of neck; underside of head blackish, 
about the same shade as sides of neck; sides of flanks darker near 
lower border and along sides of abdomen; inguinal area sometimes 
dusky gray or even blackish gray ; otherwise underparts of body pure 

Color in winter pelage. — Entirely pure white except small black 
tips to ears. 

Skull. — Closely similar to that of arcticus, from which it is prac- 
tically indistinguishable. 

Average measurements (5 adults). — Total length, 596; tail ver- 
tebras, 63; hind foot, 164; ear from notch in dried skin, 81. 

Remarks. — L. a. bangsi appears to lack definite skull characters 
and rests only on color differences. The nearly uniform black ears 
and dusky median line sometimes present on top of the tail are the 
main differences from representatives of arcticus from Ungava. One 
skull of bangsi is remarkable for the unusual development of the 
supraorbital. In this individual the postorbital process extends back 
until the point meets and rests against a process on the squamosal, 
while the anterior process extends forward as a broad strap-shaped 
bone fusing along the inner side to the upper part of the vertical 
ridge of the malar in front of the orbit. The anterior notch is reduced 
to a small rounded foramen ; the posterior notch to a large rounded 

The opinion prevails in Newfoundland that the rapid increase of 
L. a. struthopus on the island since its introduction about forty years 
ago has resulted in the marked decrease of Arctic hares. Arctic 
hares are reported to have been formerly common and generally dis- 
tributed, but of recent years to have decreased in numbers, and those 
remaining are said to be limited to the barren hilltops. 

It is difficult to understand why a species so strictly limited to 
wooded areas as struthopus should seriously affect species of the 
open country, such as the Arctic hares, even when the areas they 
occupy are intermingled. The letter from Mr. Howley quoted in the 
remarks on L. a. struthopus states the local belief in this matter. 

Total number of specimens examined 18, from : 

Newfoundland (Canada): Bay of Islands, 1; Bay St. George, 13; Cod- 
roy, 2 ; St. Johns, 2. 


Hudson Bay Arctic Hare. 

Jjepus arcticus canus Preble, N. A. Fauna No. 22, pp. 59-61, October 31, 1902. 
Type from Hubbart Point, west coast of Hudson Bay, Keewatin, Canada ; 
No. 106S60, $ ad., U. S. National Museum (Biological Survey Collection) ; 
collected by E. A. Preble, August 17, 1900. 
85595— No. 29- -09 5 


Geographic distribution. — Barren Grounds of northern Canada 
south to York Factory, Keewatin, and northern shores of Great 
Slave and Great Bear lakes. Vertical range from sea level up to an 
undetermined altitude; zonal range, Arctic. 

General characters. — Closely similar to specimens of arcticus from 
Ungava, but the three available summer specimens differ in the paler 
tone of gray on the head and body and the greater amount of whitish 
and gray on the ears. 

Color in summer pelage. — Top and sides of head dull buffy gray ; 
top of nose dull fulvous buffy ; back and sides of bod}'' slightly paler 
iron gray than arcticus; sides of body nearly like back, but a little 
less grizzled and darker; rump patch dusky, but not so dark as in 
arcticus; outside of fore and hind legs and feet white, or with a 
little gray on legs; front half of outside of ears blackish, strongly 
grizzled with gray and bordered along front edge with whitish; 
posterior half of outside of ears blackish at base and white thence 
to near tip, including a distinct white line along posterior border; 
white area on back of ears extending as a subterminal whitish band 
across front and inside, thus isolating a small black tip as in arcticus, 
but the white band broader in canus; underside of neck plumbeous 
gray slightly grizzled with whitish gray like sides of body; rest of 
underparts white. 

Color in winter pelage. — Entirely pure white except small black 
tips to ears. 

Skull. — The single adult skull examined from the type region (Fort 
Churchill) is absolutely indistinguishable from skulls of arcticus 
from Ungava. 

A skull from Fort Eae is remarkable for the strong frontal de- 
pression, the plane of the depression extending far out on the top of 
the rostrum. The rostrum is proportionately long and unusually 
narrow, the bullae are small and deeply embedded, and the molars 
are small. A Fort Anderson skull is narrow and slender, with the 
supraorbitals strongly ossified on both anterior and posterior 
processes. These skulls probably represent more nearly the typical 
skulls of the form called canus than those from the coast of Hudson 
Bay, which are nearer arcticus. 

Remarks. — This is a poorly marked subspecies, distinguishable 
from arcticus mainly by the slightly paler color of the upperparts 
and the larger amount of white on the ears in summer. Unfor- 
tunately I have seen skins of only three immature summer specimens, 
so the constancy of this difference is yet to be determined. 

A specimen in the National Museum, less than half grown, from 
Cambridge Bay, Victoria Land, differs strikingly from any other 
seen. It has the upperparts dull tawny, or slightly cinnamon buffy, 
grizzled with whitish; the ears dusky, grizzled with pale gray in 


front and inside, and the white margin on posterior border extending 
as a narrower dingy buffy whitish band across front and inside of 
ear, isolating a small black tip. The specimen is so different from 
anything seen from elsewhere that it appears possible there may be 
an undescribed form on the islands north of the Barren Grounds. 

The southern breeding limit of canus is marked by the northern 
limit of trees. This limit can be roughly marked by a line drawn 
from Fort Churchill, on the west side of Hudson Bay, northwesterly, 
passing a little north of Great Slave and Great Bear lakes. In 
winter they range south some distance into the partly wooded region, 
reaching at least as far as Fort Rae, Mackenzie, and York Factory, 

Since the foregoing account of this form was written additional 
information has been secured. Through the courtesy of Dr. J. A. 
Allen, of the American Museum of Natural History, I have had the 
opportunity to examine two specimens of canus collected by E. T. 
Seton and E. A. Preble on August 14 and 19, 1907, at Aylmer Lake, 
Mackenzie, and find that they confirm the validity of this form. 
The smaller of the specimens differs but little from the type, except 
that the upper surface of the fore feet and legs is dull grayish brown 
and the nape, sides of body, and rump are suffused with more black- 
ish; the sides of the body being a clearer, more dusky gray. The 
larger of these specimens a has the ears almost completely jet black 
on both sides; the middle of the back is a little darker gray than the 
type, and the nape, sides of body, and rump are much more blackish ; 
the rump, broad lateral line, and underside of head and neck are 
distinctly blackish with dark plumbeous gray underfur, the blackish 
of the lateral line encroaching on the sides of the abdomen, restricting 
the white median area. The top and sides of head are dark, slightly 
buffy gray with a dull buffy suffusion on ocular area. The top of 
the head is much like the middle of the back, differing mainly in its 
slightly buffy tinge. 

Total number of specimens examined 11, from: 

Franklin: Cambridge Bay, Victoria Land, 1. 
Keewatin: Fort Churchill, 2; Hubbart Point, 2. 
Mackenzie: Fort Anderson, 1; Fort Rae, 3; Aylmer Lake, 2. 


Greenland Hare. 

(PI. IV, fig. 1; PL V, fig. 1.) 

Lepus grcenlandicus Rhoads, Am. Naturalist, XXX, p. 236, March, 1896 (au- 
thor's separates issued February 20, 1896). Type from Robertson Bay, 
northwestern Greenland, No. 1486, ad., Academy of Natural Sciences, Phila- 
delphia ; collected by C. E. Hite, August 2, 1892. 

"Am. Mus. Nat. Hist., No. 29060. 


Geographic distribution. — Northwestern coasts of northern Green- 
land and Ellesmere Land. Vertical range from sea level to an unde- 
termined altitude; zonal range, Arctic. 

General characters. — Larger than arcticus; head and body of 
adults white throughout the year, but changing in summer from the 
snowy white of winter to a more grayish white ; ears in winter pure 
white, in summer mainly dusky gray, with a small black tip at 
all seasons; claws very large; upper incisors extremely long and 

Color in summer pelage. — Top of head varying from dusky gray- 
ish white to pale dull whitish buffy ; sides of head and back slightly 
dusky whitish, the duskiness due to a thin intermixture of black 
hairs; outside of ears on posterior half, most of inside and subter- 
minal band across front white, isolating a small dusky or black tip; 
basal two-thirds of front half of outside of ears dusky gray, some- 
times tinged with dull buffy ; rest of head, body, legs, and feet pure 

Color of winter pelage. — Entirely pure white, except small jet 
black tips to ears. 

Juvenal pelage. — Top of head a varying shade of brownish buffy 
grizzled with whitish tips to hairs; sides of head buffy whitish; 
entire upperparts of neck and body varying from dull whitish with 
a slight buffy suffusion to dull whitish buffy, darkest on top of back 
and palest on sides; feet and legs similar to sides of body; entire 
underparts pure white; front half of outside of ears varies from 
ding} 7 yellowish buffy to dull buffy whitish; inside of ears similar 
but paler; back of ears white; tip with a small dusky point; top of 
head and ears always darker than back; no sign of a dark gray 
summer pelage similar to that of arcticus in the southern part of 
its range. 

Skull. — Size large (exceeded among American forms only by that 
of othus) ; above generally similar in form to that of the subspecies 
of arcticus, but the premaxillae taper anteriorly to a long narrow 
point, from which extend the extremely long, slightly curved, and 
outreaching upper incisors, giving a slender beaklike form to the 
upper mandible, in strong contrast to its form in all other American 

Arerage measurements (5 adults). — Total length, 664; tail ver- 
tebrae, 73 ; hind foot, 146 ; ear from notch in dried skin, 75. 

Remarks. — This is one of the most strongly differentiated forms 
among the known Arctic hares of America. Its excessively heavy, 
wool-like coat of fur, the great development of the claws, and the 
remarkably long tapering upper mandible, with the extremely long, 
extended, slightly curved upper incisors, are characters not ap- 
proached by any of its known relatives on this continent. So far as 


known it is confined to the north coast of Greenland and Ellesmere 
Island, its distribution appearing to coincide with that of the north- 
ern musk ox (Ovibos wardi). 

The stout fossorial claws and long outreaching incisors of this 
species are evidently developed to assist in obtaining food in a region 
where the extreme rigors of a high Arctic climate and the dwarfed 
vegetation on land hard frozen and covered with ice and snow so 
large a part of the year make it difficult for rodents to maintain 

The excessive thickness of the pelage on this species gives the coat 
a woolly or fleece-like effect. The young (which are about one-third 
grown in July) have an odd resemblance to very young lambs, owing 
to their dingy whitish woolly coats. 

In the spring molt the old pelage is so matted that it comes off in 
large patches, leaving shreds and ends hanging to the still attached 
portions, thus giving the animals a rough and ragged appearance. 

Arctic hares are known to occupy both coasts of southern Green- 
land, but I have seen no specimens from that region, and therefore 
am unable to give any further information concerning them. From 
their distribution, however, they should be most closely related to 
grosnlandicus, but no doubt differ at least subspecifically from that 
species. The notes regarding them by Brown, in his paper on the 
Mammals of Greenland, indicate that, unlike grcenlandicus, they 
become brown in summer (P. Z. S., 1868, p. 351.) 

Total number of specimens examined 32, from : 

Ellesmere Land: Baclie Peninsula, 1; Buchanan Bay, 4. 

Greenland: Cape Alexander, 2; Holstenberg, 1; Northumberland Island 

(near Cape Alexander), 15; Olriks Bay, 1; Robertson Bay, 4; Sonn- 

tag Bay, 1 ; Woodland Bay, 3. 

Alaska Tundra Hare. 

Lepus othus Merriam, Proc. Washington Acad. Sci., II, p. 28, March 14, 1900. 
Type from St. Michael, Alaska; No. 15S83, ad. (skull only), U. S. National 
Museum ; collected by L. M. Turner, February, 1877. 

Geographic distribution. — Tundras of northern and northwestern 
Alaska, exclusive of the Peninsula and Bristol Bay section. Vertical 
range from sea level up to over 2,000 feet altitude; zonal range, 

General characters. — Largest of the American Arctic hares, even 
exceeding gramlandicus / feet very large; color much darker and 
more dusky brownish in summer than any other American form. 

Color of summer pelage (Kotzebue Sound). — Top of head blackish 
brown, finely grizzled with buffy gray; top and sides of nose and 
about mouth dark cinnamon buffy; this cinnamon buffy area extends 
up on top of nose, dividing at forehead, and extends back on each 


side as a darker, more reddish cinnamon area covering sides of head 
around eyes and inclosing a narrow pure white orbital ring; a patch 
on each side of nose, in front of eyes, distinctly grizzled gray over- 
lying the cinnamon under color; posterior half of cheeks and basal 
two-thirds of ears in front dusky, grizzled with buffy, like top of 
head; terminal third of anterior outer half of ears, and a band 
extending to base of ears back of the dusky anterior area, glossy 
black ; tip and a long patch on posterior part of inside of ears black- 
ish; posterior half of ears on outside dusky grayish becoming pure 
white along terminal hal"* 2 of posterior border ; inside of ears crossed 
by a broad subterminal cinnamon buffy band isolating the blackish 
tip ; nape and top of back dark dusky brown, shading into a slightly 
grayer or more plumbeous brown on sides and entirely covered with 
a fine thin grizzling of gray; tail white with scattered dusky hairs 
on upper side; front of fore legs and top of fore feet grizzled dark 
brownish buffy ; outside of hind legs similar to sides of body but 
becoming dingy buffy along anterior border ; tops of hind feet white ; 
rump dull blackish brown with scanty grizzling, thus forming a 
poorly defined dusky rump patch; underside of neck dusky smoky 
gray grizzled sparsely with clear gray ; rest of underparts white. 

Color of winter pelage. — Pure white except small black tips of ears. 

Skull. — Large and massive; largest of the American Arctic hares, 
even exceeding in size the skull of grcenlandicus, from which the short, 
heavy mandible and strongly incurved upper incisors at once dis- 
tinguish it; general proportions and appearance closely like that of 
arcticus, but much larger, with very broad and heavy zygomatic arch, 
anterior end of zygomatic arch heavier and more smoothly rounded 
than in the other forms. 

Reworks. — The present species is remarkable for its dark blackish 
brown color in summer, its large size, massive skull, and extremely 
large hind feet. The dark color contrasts strikingly with the pale 
iron grays of the summer pelage in canus and other eastern forms of 
arcticus. While only one summer skin has been available, yet a 
fairly good series of over a dozen good adult skulls from various 
localities agree in their great size and other characters, which appear 
to confirm the validity of otlius as a well-marked species. Lepus othus 
is extremely rare in collections. The only summer specimen I have 
seen is the Kotzebue Sound example in the Philadelphia Academy of 
Sciences, which is described above. It is possible that material from 
the northern coast east of Point Barrow may prove the intergrada- 
tion of othus with canus or arcticus, but the series now available 
shows no signs of this. 

Total number of specimens examined 13, from: 

Alaska: Kotzebue Sound (Choris Peninsula), 1; Nulato River, 1; St. 
Michael, 10; Yukon, 1. 


Alaska Peninsula Hare. 

Lepus poadromus Merriam, Proc. Washington Acad. Sci., II, p. 29, March 14, 
1900. Type from Stepovak Bay, Alaska Peninsula; No. 9S068, ad., U. S. 
National Museum (Biological Survey collection) ; collected by Charles 
Palache, July 9, 1899. 

Geographic distribution. — Peninsula of Alaska and Bristol Bay 
district of Alaska. Vertical range from sea level up to an unde- 
termined altitude; zonal range, Arctic. 

General characters. — In summer, upperparts dull cinnamon brown, 
becoming distinctly rusty or reddish cinnamon on head; tail very 
small, dusky gray above and below ; front feet brownish cinnamon ; 
hind feet white. 

Color in summer pelage. — Head grizzled rusty brownish cinnamon, 
becoming plain dull dark reddish cinnamon about nose and around 
eyes on sides of head; a narrow patch of dull buffy on upper and 
lower eyelid ; front of fore legs and tops of fore feet grizzled brown- 
ish cinnamon a little paler than sides of head ; entire back and sides 
of body dark cinnamon brown more dusky and less reddish than 
head, and finely but thinly grizzled with dull buffy or dull grayish 
buffy; rump more dusky than top of back and forming a poorly 
defined dusky rump patch ; outside of hind legs dull cinnamon brown 
much like back, but a little paler; tops of hind feet white; tail 
smaller and shorter than in any other member of the group, and 
otherwise strikingly peculiar in being dusky gray above and dingy 
gray below, the color on upperside being produced by a mixture of 
grayish white and blackish hairs; underside of neck dull slightly 
cinnamon brownish, a little duller than sides of body ; chin whitish, 
shading back into dull whitish gray on rest of underside of head; 
middle of underside of body from breast to base of tail and inside 
of legs pure white; sides of abdomen mainly dull brownish gray; 
outside of ears in front grizzled cinnamon brown, much like back, 
but becoming more dusky on terminal half; outside of ears on 
posterior half whitish, becoming pure white along posterior border; 
anterior border on terminal half whitish, shading into a small, 
indistinct, dusky tip ; inside of ears brownish and dusky overlaid and 
mixed with grayish white hairs. 

Skull. — Closely similar to arcticus, but rather slenderer, with nasals 
averaging shorter; distinguishable at once from othus by small size 
and slender proportions. 

Measurements (1 skin). — Total length, 600; tail vertebras, 53; hind 
foot, 147 ; ear from notch in dried skin, 78. 

Remarks. — This species, judging from the single summer skin at 
hand, is the most strongly marked externally of any member of the 


group. Its dark cinnamon-brown color and short dusky tail being 
quite unlike anything else. With such striking external markings 
the surprising lack of characters in the skulls, of which a good 
series of adults is in the Biological Survey collection, is remark- 
able. So far as known, poadromus has a very restricted distribution. 
A broken skull from Nushagak, at the head of Bristol Bay, is like 
skulls of poadromus from Becharof Lake. A winter skin from 
Nushagak is pure white with small black tips to the ears, showing 
that this species has the customary winter pelage. 
Total number of specimens examined 10, from : 

Alaska: Between Portage Bay and Becharof Lake (Alaska Peninsula), 6; 
Cold Bay (Alaska Peninsula), 1; Kewatna Bay, Shelikoff Strait 
(Alaska Peninsula), 1; Nushagak, 1 ; Stepovak Bay (Alaska Penin- 
sula), 1. 



Strictly speaking, the white-tailed jack rabbits are hares, and 
belong to the subgenus Lepus. The group consists of a single species, 
L. campestris, and its two subspecies, townsendi and sierrce. They 
are large, heavy bodied animals, with a combination of external and 
skull characters which place them in a nearly intermediate position 
between the typical Arctic hares and the black-tailed jack rabbits of 
the subgenus Macrotolagus. The long ears and long, slender legs 
give campestris and its subspecies much similarity in form to the 
black-tailed jack rabbits, while the skull is much more like those of 
the arcticus group. This intermediate character of campestris is 
made still more significant by the fact that its range also is in the 
country intermediate between the areas occupied by the Arctic hares 
and the black-tailed jack rabbits (see fig. 4). The close resemblance 
between occasional skulls of campestris and of Lepus calif omicus 
melanotis from overlapping parts of their ranges on the southern 
part of the Great Plains has been mentioned elsewhere. 

The type of campestris came from the extreme northern border of 
its range, near Carlton House, on the plains of the North Fork of the 
Saskatchewan Kiver, Canada. From that region south it occupies 
the Great Plains, lying east of the Rocky Mountains, to Kansas and 
Colorado. Within the United States the species crosses the Rocky 
Mountains and extends through the Great Basin to the east slopes of 
the Sierra Nevada and Cascade Mountains. East of the Rocky Moun- 
tains only typical campestris is known, but west of these mountains 
differences in local conditions have modified the species into two geo- 
graphic races, townsendi and sierra. L. campestris as a species is 


usually characteristic of broad, open plains, but it follows open coun- 
try up mountain slopes to altitudes varying from 10,000 to 12,000 
feet in both the Rocky and the Sierra Nevada mountains (see fig. T). 
The southern border of their range overlaps the northern part of the 
range of the black-tailed jack rabbits. 

In the northern and most elevated parts of their range, wherever 
the "winters are severe and accompanied by regular snowfall, campes- 
tris, townsendi, and sierra? have a nearly pure white winter pelage, 
its thickness and whiteness increasing northward. In the extreme 
southern parts of their ranges, where the winters are milder and the 
snowfall irregular, the winter coat is rarely or never as completely 
white as it is farther north, but is more or less buffy on the head and 
upperparts of the body. In summer the top of the back, sides of the 
body, and rump are practically of the same shade; but in winter 
specimens in which the change of color is incomplete, the rump and 
sides of the bod} 7 are distinctly paler than the top of the head and 
back, thus imitating imperfectly the distribution of color on the 
white-sided jack rabbits. The subspecies townsendi commonly has 
the top of the tail mixed with black, and this character is most 
strongly developed in southwestern Colorado. One specimen from 
Coventry, Colorado, has the top of the tail occupied by a broad band 
of black, almost as large as in a strongly marked form of the black- 
tailed group, and in this region narrow but continuous median black 
lines on the tail are usually present. In true campestris the tails are 
nearly always uniformly white and never so strongly marked as in 
these extreme cases of townsendi. The ranges of the subspecies cam- 
pestris and townsendi meet along the summit of the Rocky Mountains 
in Colorado. Using the color of the upperparts in summer pelage 
as a criterion, specimens from the east and west drainages of the 
Rocky Mountains fall respectively into two sets marked by color 
differences; typical campestris is yellowish buffy, while townsendi 
and sierrce are distinctly gray. Northern specimens of campestris in 
full white winter pelage have a strong general resemblance to winter 
specimens of Arctic hares; but the buffy tips of the underfur of 
campestris contrasted with the pure white underfur of the Arctic 
hares is an unmistakable character. 


Average measurements of Lepus campestris and subspecies. 







a ! .s 









a .1 ■ 


Bf g 2 





Origin of specimens 









M C 

O dJ 

M S- 









- VI 


























a)"*- 1 















Lepus campestris 













Eastern Colorado and 


Lepus campestris town- 








24.4 22.2 



Washington and Ore- 



Lepus campestris sierrse. 











Hope Valley, California 

a The skull of the type is broken ; the skull measurements given here are the averages 
of two adults from Mono Lake, California. 


White-Tailed Jack Rabbit. 

(PI. IV, fig. 3; PL V, fig. 3.) 

Lepus campestris Bachman, Journ. Acad. Nat. Sci. Philadelphia, VII, pt. 2, pp. 
349-353, 1837. Type from plains of the Saskatchewan, Saskatchewan, 
Canada, probably from near Carlton House; collected by John Richardson. 

Geographic distribution. — Great Plains of Saskatchewan in Al- 
berta, Saskatchewan, and Manitoba, Canada, and thence south on 
plains of the United States, east of the Rocky Mountains, over Mon- 
tana, Wyoming (except extreme southwestern part), the Dakotas, 
Minnesota to extreme southeastern corner (Lanesboro), Iowa east 
to the Mississippi River (Muscatine), Nebraska, northern half of 
Kansas, Colorado east of summit of the Rocky Mountains, and mid- 
dle northern border of New Mexico. Vertical range from less than 
1,000 feet in Iowa up to at least 10,000 feet on the mountains of 
Colorado ; zonal range, mainly Upper Sonoran and Transition on the 
plains of the western United States, extending into Canadian on the 
mountains and in the northern part of its range. 

General characters. — A large, heavy bodied species, usually with 
the tail at all seasons entirely white ; two annual molts ; upperparts 
of body in summer becoming light yellowish buffy; in winter pure 
white, except in extreme southern part of range, where back becomes 
pale buffy gray and sides of body and rump whitish; ears always 
buffy or buffy gray with black tips, except in winter in extreme north- 
ern part of range, where mainly w 7 hite with black tips. 

Color in fresh summer pelage. — Top and sides of head and body 
nearly uniform, varying from a pale dull golden gray to dull yel- 


lowish buffy gray, usually underlaid and darkened by the brownish 
color of underfur showing through; sides of head slightly paler or 
grayer than back, with sides of nose and ring around eyes white 
(yellowish buffy in young individuals) ; nape pale dull buffy, vary- 
ing to buffy whitish and dull grayish ; rump similar to rest of back, 
but a little paler on sides; entire tail usually white, but sometimes 
with more or less dusky hairs along middle of upperside, even to the 
extent of forming a narrow, dusky median line ; front and outside of 
fore legs, including tops of fore feet, dingy buffy, sometimes more or 
less tinged with grayish and sometimes with ochraceous; outside of 
hind legs a little duller and usually more of a drab gray than back; 
tops of hind feet whitish, sometimes tinged with buffy ; rump in mid- 
summer similar to rest of back, but pale (especially on sides) in early 
spring and late fall; underside of neck varies from dull buffy with 
a grayish tinge to dull ochraceous buffy; rest of underparts white; 
ears on outside of anterior half dusky brownish, heavily washed with 
ochraceous buffy and varying to paler buffy gray; anterior border 
strongly edged with ochraceous buffy, varying to dull buffy or gray- 
ish buffy in the grayer-eared specimens; posterior half of outside of 
ear white, with a broad terminal black patch extending to include 
border of ear at tip ; inside of ear with a long dusky patch near pos- 
terior side more or less grizzled with buffy or buffy gray, and a paler, 
more whitish, or buffy whitish edging along posterior border. 

Winter pelage. — In the northern part of the range— Canada, Mon- 
tana, Wyoming, the Dakotas, and Minnesota — the summer coat 
changes in winter to pure white, except irregular areas on tops of 
fore feet, on top of nose, and about eyes, which become fulvous buffy; 
front and inside of ears become deep rusty or reddish ochraceous buffy 
underlaid with dusky or dark buffy gray, well-marked patch at pos- 
terior tip always glossy black, as in summer pelage ; underfur on back, 
neck, and head usually dark pinkish buffy approaching reddish brown 
in some specimens and showing more or less through wherever the 
heavy overlying white coat is disturbed. 

In southern part of range from Colorado, east of Rocky Mountains, 
through Kansas and Nebraska, winter change much less complete; 
head, ears, back, and sides of body merely become much paler buffy 
than in summer and rump and hind legs whitish with a slight buffy 
wash. Some individuals, notably from Denver, Colorado, and Valen- 
tine, Nebraska, have rump, shoulders, and sides of neck and body 
more whitish than top of head and middle of back; the latter area 
grayish buffy in the Denver specimen and whitish with a strong 
brownish tinge in the Nebraska one. One winter specimen from 
El Paso County, Colorado, has head, ears, and body dark buffy, 
nearly as in summer, but rump distinctly paler and more dirty whit- 
ish, forming a well-marked rump patch. 


Skull. — Comparatively short, high arched, with extremely broad 
nasals, giving a broad blunt rostrum; interorbital area strongly 
depressed between high-arched, wing-like supraorbitals; anterior 
process of supraorbital well developed and inclosing a deep, irregular 
notch; postorbital process short, broad at base, and tapering rapidly 
to a blunt point, which usually stands out widely divergent from 
skull, with a broad, deep notch between ; but not rarely the posterior 
point extends back to meet a bony process on squamosal and thus in- 
closes a broad obovate foramen; braincase broad, depressed, or flat- 
tened above, more or less angularly ridged on sides; bulla? medium 
sized, proportionately smaller than in the Lepus calif ornicus group ; 
rather flattened below and irregular in outline; zygomatic arch mas- 
sive; malars broad, flat, with a deep pit anteriorly; molar series 
broad and massive; rostrum deep and broad at base, with premaxil- 
laries tapering to a slender and projecting point and long incisors, 
thus giving this part of rostrum below nasals a more strongly ex- 
tended form than in the black-tailed jack rabbits, with incisors less 
strongly incurved ; postpalatal fossa very broad and deep. 

Average measurements (5 adults) . — Total length, 605 ; tail vertebrae, 
92 ; hind foot, 149 ; ear from notch in dried skin, 95.6. 

Remarks. — Summer specimens of campestris show considerable 
individual variation in color on the upperparts of the head and body, 
from dark yellowish buffy, with the underlying dusky brownish 
ground color showing through and darkening the general effect, to a 
much paler and brighter, or more golden, buffy varying to grayish 
buffy. The yellowish shade is always present and usually strongly 
marked as compared with the clearer gray of toicnsendi and sierra?. 
In full summer pelage in all parts of its range this form appears to 
have the rump very slightly if any paler than the back. The traces 
of black or dusky along the top of the tail are more often present in 
summer than in winter, and are most frequently present in specimens 
from the southern half of its range. The change into the pale winter 
pelage takes place between the last of October and the end of Novem- 
ber. Usually the first change is the appearance of a paler rump 
patch. One individual from Park County, Montana, had scarcely 
begun to change on October 25, while one from Valentine, Nebraska, 
had taken on the pale winter coat by November 13. Midwinter speci- 
mens from Denver and from El Paso County, Colorado, have strongly 
buffy backs, darker than those from Nebraska at the same season. 
There is a great amount of variation in the winter coat between these 
buffy backed Colorado animals and the pure white ones from farther 
north. The reddish buffy or buffy brown color of underfur of the 
white winter animals varies much in intensity and in the amount 
of suffusion it shows about the head and neck. A February specimen 


from Fort Custer, Montana, has the strong reddish, almost chestnut 
brown, color on the underfur showing conspicuously through the 
rather thin overlying layer of white on the surface of the upperparts, 
especially on the neck. The surface of the white on the middle of 
the back in this specimen is washed with rusty buffy, giving the 
appearance of a slightly scorched area ; the tops of the fore feet are 
rich rusty buffy and the hind feet strongly patched with a paler 
shade of the same, mixed with white. 

The various stages of the molt into summer or winter pelage, in 
addition to individual variation, make up an almost endless amount 
of difference among individuals of this species. True L. campestris 
appears to be limited to the region east of the Rocky Mountains. 
Two specimens from central northern New Mexico belong here. 
The darkest and most brownish buffy individual seen is one shot 
October 10 in Trego County, Kansas. Two specimens, one-fourth 
grown, collected at Fort Pierre, South Dakota, the last of May, have 
a slightly reddish brown shade over the entire upperparts and are 
washed and grizzled on the surface with silvery gray. 

A series of four adults from Madison, Minnesota, are the largest 
examined from any part of the range, and unless these individuals 
were chosen by the collector from a large number on account of their 
size, then campestris must reach its greatest average size in this 

The type of campestris was a mutilated hunter's skin in winter 
pelage. It was collected by Richardson, who states that the species 
was common on the plains of the North and South Saskatchewan 
rivers. E. A. Preble, in the light of his knowledge of the country 
and of the work of the early explorers in northern Canada, considers 
it probable that Richardson's specimen came from near Carlton 
House, on the lower course of the North Fork of the Saskatchewan 
River. Preble considers Richardson's northern limit of 55° latitude 
for the species as almost certainly erroneous. The specimen killed 
by Drummond in September on the North Saskatchewan above Carl- 
ton House is the northernmost record we know for this species. 
The amount of white in the winter pelage increases steadily to the 
northward until near the northern border of its range campestris 
in winter becomes almost as completely white externally as the Arctic 

Total number of specimens examined 132, from : 

Manitoba (Canada): Carberry, 1. 
Saskatchewan (Canada): Indian Head, 1. 
Alberta (Canada): Greenfield, 1. 
Minnesota: Grant County, 2; Madison, 4. 
Iowa: Ruthven, 3. 

North Dakota: Devil Lake, 1; Fort Pierre, 1 ; Fort Union, 1; Harrisburg, 
1 ; Mandan, 1. 


South Dakota: Corral Draw, 4; Deadwood, 1; Fort Meade, 1; Pierre, 1; 

Rapid City 2; Sioux Falls, 1. 
Nebraska: Fort Kearney, 1; Loup Fork, 1; Perch, 1; Platte River (90 

miles above Fort Kearney), 1; Valentine, 1. 
Kansas: Coyote Station, 2; Garden City, 2; Lawrence, 2; Long Island, 1; 

Red Fork (60 miles west of Fort Riley), 1; Winona, 6; Trego 

County, 4. 
Montana: Chief Mountain, 1; Cinnabar, 1; Fort Custer, 2: Frenchman 

River, 1 ; Little Dog Creek, 1 ; Porcupine River, 1 ; Powder River, 1 ; 

Robare, 1; Three Buttes, 2; Yellowstone River (Three Buttes), 1. 
Wyoming: Big Piney, 1 ; Bitter Creek, 1; Bridger Pass, 5; Cheyenne, 2; 

Deer Creek, 6 ; Devil Tower, 1 : Douglas, 2 ; Fettermann, 1 ; Fort 

Sanders, 1 ; Fort Steele, 1 ; Medicine Bow Mountains, 1 ; Meriden, 1 ; 

Newcastle, 3 ; Percy, 6 ; Rock Creek, 1 ; Spring Creek, 1 ; Wamsutter, 

2; Woods post-office, 1; Yellowstone Park (head of Glenn Creek), 1. 
Colorado: Antonito, 1; Cache la Poudre River, 1; Colorado Springs (15 

miles east), 1; Como, 1; Deer Creek, 1; Denver, 1; East Dale, 1; 

Eastonville. 2; Fort Garland, 1; Longmont, 1; Loveland, 5; Medano 

Ranch (15 miles northeast of Mosca), 6; Mount Whiteley (25 miles 

north of Kremmling), 1; Payton, 1; Salida, 1; Sterling, 1; Villa 

Grove, 5. 
New Mexico: Hopewell, 1. 


Western White-tailed Jack Rabbit. 

Lepus toionscndi Bachman, Journ. Acad. Nat. Sci. Philadelphia, VIII, pt. 1, pp. 
90-94, pi. II, 1839. Type from old Fort Walla Walla, Washington ; 9 yg. ; 
(present location unknown; probably no longer extant) ; collected by J. K. 

Geographic distribution. — Great Basin region, including east slopes 
of Cascade Range, and thence east to Rocky Mountains, occupying 
eastern Washington and Oregon, and north to Fairview, in Okanogan 
Valley, British Columbia ; and from the northeastern corner of Cali- 
fornia easterly through northern Nevada, western and southern 
Idaho, extreme southwestern Wyoming, most of Utah, and Colorado 
from western border to summit of Rocky Mountains. Vertical range 
from about 1,000 feet in eastern Washington to 12,000 feet in Colo- 
rado; zonal range mainly Upper Sonoran and Transition, but reaches 
up to Hudsonian in the mountains of Colorado. 

General characters. — In summer similar to campestris, but head and 
body nearly uniform gray, entirely lacking the yellowish buffy shade 
of campestris. Winter specimens in white pelage not distinguishable 
from campestris, except by the smaller size and narrower black tips 
to ears; in southwestern Colorado, winter specimens not white, but 
top of back becomes pale creamy or buffy gray, contrasting with the 
bright yellowish, almost golden buffy, backs of some winter specimens 
of campestris from east of the mountains in Colorado. 


Color of fresh summer pelage. — Head and upper parts of body 
nearly uniform dark gray, varying from an almost silvery tone to a 
duller and slightly pinkish gray with an underlying brownish shade ; 
underfur tipped with dusky brownish, darker and less buffy than in 
campestris ; front of fore legs and tops of fore feet dull grizzled 
buffy gray, sometimes becoming dingy buffy on tops of feet; outside 
of hind legs varying from plain dull gray to drab gray ; tail white, 
sometimes with a considerable amount of dusky or black, forming a 
narrow but well-marked median line on top ; tops of hind feet white, 
sometimes with a slight mixture of gray, or a little buffy about toes; 
nape dingy gray, sometimes with a smoky brown or dull buffy brown 
suffusion ; front half of outside of ears dusky gray ; posterior half 
white with a distinctly more restricted black tip than in sierra* or 
campestris ; inside of ear with a dusky area along posterior side and 
bordered anteriorly with dull rather pale ochraceous buffy; pos- 
teriorly bordered with white, the latter sometimes suffused with deep 
buffy ; tip of ears in front edged with black ; orbital area and sides of 
nose sometimes more or less strongly shaded with cinnamon buffy; 
underside of neck dull drab grayish shaded with brownish or dull 
buffy, distinctly less yellowish and more brownish gray than in 

Color of winter pelage. — Specimens from Utah, Nevada, and thence 
north become white in winter and practically indistinguishable from 
campestris except by smaller size and less black on tips of ears; 
winter specimens from southwestern Colorado become much more 
whitish than in summer, but, as in the case of campestris east of the 
mountains in that State, only a partial change takes place. In strong 
contrast to the bright yellowish buffy backs of Colorado specimens of 
campestris in winter, toumsendi from the same State at this season 
becomes much paler or more whitish on shoulders, sides of body, and 
rump, and paler buffy gray on top of head and back; the ears become 
paler and grayer than in summer; nape grayish white; top of tail 
white with dusky along median line on top, varying from scattered 
hairs to a strong well-marked black band in several specimens from 
Coventry, in one case equaling ordinary texianus in amount of black; 
tops of fore feet and legs dingy buffy brownish or dull grayish buffy ; 
outside of hind legs whitish or dull whitish gray; underside of neck 
varying from dull brownish buffy to dull ecru drab, always more or 
less strongly washed with whitish or lighter buffy; well-marked 
rump patch dull whitish, varying to pale dull iron gray. 

Two white winter specimens from Utah have head and ears much 
as in ordinary campestris. 

Winter pelage (Osoyoos, British Columbia, January 28, 1909). — 
Upperparts of head and body pale gray, a little darker on top of 
head and more whitish gray on sides of head, body, outside of thighs, 


and on rump; tops of hind feet dull whitish mixed with dull gray, 
with a little dull buffy on sides of feet and toes ; tops of fore feet and 
legs dingy grayish buffy; outside of ears in front slightly darker 
gray than top of head; tip of ears with a narrow black border in 
front and a small black patch about half an inch long behind ; under- 
side of neck dull buffy washed with whitish, rest of underparts pure 

This specimen shows no trace of the salmon buffy so conspicuous on 
the head, ears, and legs of winter specimens of L. townsendi sierrce. 

Skull. — Closely similar in general appearance to that of true 
campestris, but averages smaller and lighter, with rostrum narrower ; 
bullae smaller; palatine foramina narrower; postpalatal fossa nar- 
rower ; and molar series smaller. As in campestris old, much ossified, 
specimens have point of postorbital process extending back to touch 
small process on squamosals, thus inclosing a broad foramen; ante- 
rior process of supraorbitals in such individuals often extends for- 
ward and nearly or quite closes anterior notch. 

The skull differences given above are merely average, as many 
skulls of the two forms are practically indistinguishable. Skulls 
from western Colorado are larger than in typical townsendi, and in 
many instances are indistinguishable from those of campestris from 
east of the mountains in that State. 

Average measurements (5 adults). — Total length, 575; tail ver- 
tebrae, 79 ; hind foot, 149 ; ear from notch in dried skin, 102. 

Remarks. — For many years Lepus townsendi was confused with 
campestris until properly characterized by Doctor Merriam in a re- 
vision of the campestris group published in 1901.° It occupies most 
of the elevated plains and open mountain slopes of the Great Basin, 
and becomes white in winter throughout most of its range, except in 
the plains of the Columbia and southwestern Colorado, where the 
change appears to be incomplete. The summer pelage from western 
Colorado is very close to that of typical townsendi, but the dusky or 
black line on the upper side of the tail is much more strongly de- 
veloped and in some cases approaches its condition in the black-tailed 
jack rabbits. L. c. townsendi intergrades with campestris in middle 
southern Colorado. One young individual from Antonito on the 
south central border of the State is as gray as typical townsendi. 
though several adults from the same section are nearer campestris, 
though evidently intergrades. An April specimen from Delta 
County is even a little darker gray than summer specimens of town- 
sendi from the type region, but the front border and inside of the 
ears are strongly ochraceous buffy, the head and body are tinged 
slightly with brownish, the tops of the fore feet are more buffy, and 

Proc. Biol. Soc. Washington, XVII. pp. 131-133. 1904. 


the underside of the neck more vinaceous buffy. This specimen is 
almost exactly duplicated in every character by one in a similar condi- 
tion of pelage from Goose Lake, California, which is within the area 
occupied by typical townsendi. 

The material collected by Warren in Colorado during the summer 
of 1907 contains some interesting records. These specimens prove the 
extension of the range of townsendi into Middle Park and up to the 
extraordinary altitude of 12,000 feet, where two specimens were 
secured on Mount Baldy, above Boreas Pass, in Summit County. 
Among these specimens those from Kremmling in Middle Park, 
Yampa, Routt County, and McCoy, Eagle County, are intermediate 
in color between typical townsendi and campestris, but are so much 
grayer than the latter that the writer refers them to townsendi. The 
Colorado specimens of townsendi, as previously noted, have distinctly 
larger skulls than those nearer the type locality. A Kremmling 
specimen is the darkest example of townsendi the writer has seen, 
being a dusky brownish gray. This color is largely due to the strong 
dusky subterminal area on the long hairs and the dark buffy brownish 
tips. In July and August these specimens frequently have the front 
of the ears blackish or dusky brownish, owing to the wearing off of 
the overlying long hairs, thus exposing the dark under color. 

Specimens from the headwaters of the Arkansas River at Salida 
and from San Luis Valley, Colorado, are in color intergrades between 
eamjiestris and townsendi, but in size are nearest campestris. A series 
of winter specimens from Coventry, Colorado, agree in having the 
sides of the body and the rump whitish, with the top of the back 
covered with a buffy grayish mantle, thus producing a color pattern 
very similar to that of the callotis group of white-sided jack rabbits. 
There is considerable variation in the shade of the buffy gray mantle 
on the backs of the Coventry series. 

In a letter dated February 11, 1909, Mr. C. de B. Green, of Fair- 
view, British Columbia, gives the first definite information concerning 
the distribution and abundance of L. c. townsendi in British Colum- 
bia, as follows: 

" With regard to this animal I may tell you that from 1893 to 1903 
it was exceedingly rare and, from the statements of the Indians and 
old inhabitants, always had been rare. I can show how rare when 
I say that during those ten years I shot three specimens. It is a fact 
which may or may not bear on the case that in 1903 I cleaned out the 
dusky horned owls from this neighborhood; in 1905 I shot 23 hares 
and about the same in the succeeding years. I think these owls kept 
the hares near the point of extinction. I notice that the golden eagles 
are now making serious raids upon them. Their range is in a tract 
of land along the Okanogan Valley about 2 miles wide and terminat- 
S5595— No. 29—09 6 


ing at Fairview, 20 miles north of the boundary line; also in Simil- 
kameen Valley for 20 miles north of the boundary. So far they have 
not spread farther north and there is little or no country suitable for 
them. The grease brush ends at Dog Lake and they will probably 
spread as far as that if vermin are kept down, for I shot a pioneer at 
White Lake, which is as far north as Dog Lake, but farther west. 
This may have come either from Keremeos, via Similkameen, or from 
Fairview, via the Okanogan." 

Total number of specimens examined 45, from: 

British Columbia: Fairview (Okanogan Valley), 1. 

Washington: Asotin, 2; Kennewick, 1; Mabton, 1; Oroville, 1; Pullman, 

1; Toucher, 1. 
Oregon: Antelope, 1 ; Guano Creek, 1 ; Heppner, 1 ; Umatilla, 1. 
California: Fort Crook, 1 ; Goose Lake, 1. 
Nevada: Ruby Valley, 2. 
Utah: Kanab, 1; Ogden, 2; Salt Lake, 1. 
Idaho: Bear Lake, 1 ; Lemhi River, 1 ; Teton Basin, 1. 
Wyoming: Hams Fork, 1 ; Henrys Fork, 1. 
Colorado: Baldy Mountain (Summit County), 2; Coventry, 4; Crawford, 

1 ; Crested Butte, 1 ; Krenimling, 1 ; McCoy, 1 ; Mill City, 1 ; Sulphur 

Springs (Grand County), 8; Tampa, 2. 


Siekba White-tailed Jack Rabbit. 

Lepus campcstris sierra; Merriam, Proc. Biol. Soc. Washington, XVII. pp. 132- 
133, July 14, 1904. Type from Hope Valley, Alpine County, California. 
No. 67863, 9 ad., U. S. National Museum (Biological Survey collection) ; 
collected September 9, 1894, by F. Stephens. 

Geographic distribution. — In summer, high slopes of Sierra 
Nevada of California, probably from Mount Shasta south to Mount 
Whitney; in winter, ranging down the east slope to Mono Lake 
region on the sagebrush plains of eastern California. Vertical range 
in summer from about 9,000 to over 12,000 feet; zonal range, Boreal. 

General characters. — Size large ; hind feet much larger and ears 
longer than in towns&ndi or campestris ; color in summer nearly as in 
townsendi; in winter white, with front of ears, top of head, and fore 
feet strongly pinkish buffy or fulvous; ears strongly tipped with 

Color in summer (type). — Scarcely distinguishable from town- 
sendi; top of head, with back and sides of body, nearly uniform dull 
grizzled gray; sides of head nearly same color as body, with a nar- 
row white ring about eyes, sides of nose deep fulvous buffy; tops of 
fore and hind feet whitish (perhaps due to change into winter 
pelage) ; front half of outside of ears like top of head, but strongly 
tipped with black ; outside of ears on posterior half whitish, with a 
broad black patch at tip; inside of ears bordered with dull fulvous 


buffy, tipped with black ; tail white, with a narrow dull gray median 
line on top ; underside of neck similar to sides of body ; rest of under- 
pays white. 

Winter pelage. — White, with the buffy of underfill* showing 
through on head and upperparts of body enough to give a tinge of 
buffy or brownish; top of head with a surface mixture of grayish 
or dull buffy; sides of nose, front half of ears on outside, borders of 
inside of ears, and tops of front feet usually more or less strongly 
vinaceous buffy or fulvous buffy, giving a much brighter shade to 
these parts than in eampestris ; tips of ears strongly margined with 
black anteriorly and with a broad black patch posteriorly. 

Color in changing pelage in fall {Mono Lake, November) . — Head 
and upperparts of body lighter gray than in summer and rump 
changing to dingy whitish ; fore and hind legs and feet white, with 
tops of fore feet more or less overlaid with vinaceous buffy ; sides of 
nose and exposed parts of ears vinaceous buffy varying to fulvous 
buffy with a less marked tinge of same mixed with gray on sides and 
top of head; some individuals have head and ears grayer, with a 
duller tinge of buffy on sides of nose and on ears, more as in summer 
but paler. 

Skull. — Scarcely distinguishable from that of townsendi. 

Measurements {type, ? ad.). — Total length, 635 ; tail vertebrae, 112; 
hind foot, 167 ; ear from notch in dried skin, 108. 

Remarks. — The range of sierrce appears to be restricted to the 
higher parts of the Sierra Nevada and adjacent eastern slope of 
California in the Mono Lake region. Its strongest characters appear 
to be the extraordinarily large hind feet and long ears. The summer 
pelage, to judge from the type, is very similar to that of townsendi. 
A series of ten fall and winter specimens of sierra? from Mono Lake, 
California, differ strikingly from eampestris at this season in the 
strong vinaceous buffy on the ears, about the nose, and on top of the 
fore feet of a majority of the series. This contrasts strongly with 
the buffy (dark ochraceous buffy in richly colored specimens), or 
buffy gray, on the ears and heads of winter specimens of eampestris. 
Among the Mono Lake series, however, are a few specimens which are 
not different in color from eampestris. The vinaceous buffy on head, 
ears, and feet in most autumnal and to a less degree in white winter 
specimens from Mono Lake is strongly contrasted with the dark 
gray of the ears and dark fulvous buffy on the sides of the nose of 
the series of summer specimens of typical townsendi and of the 
type of sierrce. If the winter specimen of townsendi from Osoyoos, 
British Columbia, is typical, then the differences between the winter 
pelage of this form and sierra 3 are well marked. The backs of the 
November specimens from Mono Lake are lighter and a little more 
buffy than the summer pelage, though much grayer and less yel- 


lowish than campestris in the same pelage. So far as the material 
at hand indicates, sierra becomes white in winter to the southern 
limit of its range. Although so large and conspicuous when moving 
about, they usually lie so closely hidden and are so strietty nocturnal 
that they are rarely seen, even in localities where their tracks and 
other signs are abundant. Their range covers both sides of the 
summit of the Sierra Nevada, and extends 12 or 15 miles west of the 
summit into Tuolumne Meadows, its greatest extension on the west 
side of the mountains. One specimen was collected by E. Heller at 
Mount Whitney, the extreme southern limit of the subspecies. Doc- 
tor Merriam says that he has seen signs of what he considers this 
hare as far north as the timberline meadows of Mount Shasta. 
Total number of specimens examined 11, from : 

California: Hope Valley (Alpine County), 1 ; Mono Lake, 10. 


The species and subspecies included in this group are Lepus ameri- 
ca?ws, L. a. struthopus, L. a. virginianus, L. a. phwo?iotus, L. a. 
bishopi, L. a. macfarlani, L. a. dalli, and L. a. columbiensis, also 
Lepus toashingtotii and L. w. klamathensis, with Lepus bairdi and 
L. b. cascadensis. They occupy a greater area than any other group 
of North American hares or rabbits, and yet, to the majority of 
people in the United States, are as little known as the Arctic hares. 
This is due to their distribution, which is mainly from the northern 
border of the United States to the northern limit of trees in Canada 
and Alaska. They range entirely across the continent from the 
Atlantic coast of New England and Canada to the Pacific coast in 
Washington and British Columbia and to the shore of Bering Sea 
in Alaska. In the United States they range south along the Alle- 
gheny Mountains to Virginia, along the Rocky Mountains to central 
New Mexico, and along the Cascades and Sierra Nevada to Donner, 
California (see fig. 8). They do not inhabit the low country 
between these high mountains, except along the extreme northern 
border of the United States. They have been introduced into the 
island of Newfoundland, but are not known on Vancouver and Queen 
Charlotte islands. 

All of these hares have two annual molts and, with the exception 
of L. washingtoni and its subspecies klamathensis, the winter pelage 
is pure white in strong contrast with the buffy brown summer coat. 
L. washingtoni is nearly the same in both pelages, and Jdamathensis 
is sometimes the same and sometimes has the white winter coat like 
most other members of the group. I have provisionally recognized 
three species, although the large series of specimens examined indi- 




cate that when sufficient material is available from the intermediate 
territory, hairdi and washingtoni with their subspecies may prove to 
be geographic races of Lepus americanus. To settle this perplexing 
question, specimens from numerous points in the mountains of 
Oregon, Washington, and British Columbia are needed. 

I. 0A VftDt c/fsc/fosAfs/s 

2 | L/V/ISH/A/GTOH/ 

3 | L . W/ISH'A/670Af/ Kl./)Ms4TH£NS/S 

4 \ L. JM£R/C/l/i/US COLUM8/£/VS/S 

H L/tMS/r/cxA/e/s s/shop/ 

L . /?M£RtC/W(/S 
L . /)M£R/C/INUS V/ff6/N//IN(JS 
L.AM£R/C/IMS Ptf/l£OA/Or(/S 
L.JMER/C/Wl/S MJCf/lfflW 
L.*M£/?/C/IA/l/S P/lUt 
Fig. S. — Distribution of Lepus americanus, L. bairdi, L. ivasliinytoni, and allied forms. 

The varying hares were the first of the American members of the 
Leporida? to become known to naturalists. Lepus americanus, the 
first species named, was described from specimens collected on 
the shore of Hudson Bay, and for a long time was confused with the 
cottontails of the eastern United States. 



[ no. 29. 

In size and color they vary from L. americanus virginianus, the 
largest and most richly colored, to L. washing to?ii and klamathensis, 
the smallest and among the dullest members of the group. The 
adults of most of the southern forms, including virgi?iianns, strutho- 
pus, columbiensis, washingtoni, and klamathensis, when in the brown 
summer coat, have the upperside of the hind feet brownish buffy 
similar to the body; but the high mountain and northern forms, 
such as bairdi, cascadcnsis, macfarlani, and dalli in summer have 
the tops of the hind feet white. In the forms in which the adults 
have the hind feet white in summer, the young, in both juvenal and 
postjuvenal pelages, have them buffy or buffy brown. 

The seasonal changes of pelage in this group result from a com- 
plete molt twice a year. Owing to the gradual change of color 
during the molt and the curious effect of the mixture of white and 
buffy hairs, it was for some time contended that the color of the new 
pelage was produced by changes in the color of the hairs and not to' 
molt. This may be readily disproved by a careful examination of a 
few molting specimens. 

Average measurements in the Lepus americanus group. 





■- S3 

2 ~ 


•£3 13 


5, : 

Origin of specimens 

Lepus americanus 

Lepus americanus stru- 

Lepus americanus vir- 

Lepus americanus phse- 

Lepus americanus bish- 

Lepus americanus mac- 

Lepus americanus dalli . 
Lepus americanus co- 


Lepus washingtoni 

Lepus washingtoni kla- 
Lepus bairdi 

Lepus bairdi cascadensis. 



133 62. 
129 66. 



39. 0.126 


65.0 34 
59. 5 31 
57. 5!30 

20. 5 16. 3 20. 4 

7119.8 27. 
2 22. 0'29. 
6 20. 7 28. 



. . 62. 
. 0159. 7 

58. 7 
55. 1 


3 21.1 

9 22.5 

5 21.4 




.7 21. 4 

. 8 19. 5 
. 8 18. 5 

23. 30 
20. 928 


9 i 21.3 28 
3 20. 27 

4 17. 6 26. 

0.58. 8 31. 
3 59. 5 32. 

7,19. 9 16. 
19. 9 16. 


10. 5 Keewatin and Saskatche- 

5 9. 2 Digby, Nova Scotia. 

6 10. 6 Pennsylvania. 

10. 4 Minnesota and Manitoba. 

2110.2] Turtle Mountains, North 

710.9 Mackenzie, Canada. 

2 ! 10. 6! Near Nulato, Alaska. 
11. 3] Central British Columbia. 

10. 4i Western Washington. 
9. 7 Fort Klamath, Oregon. 

10.5| Wind River Mountains, 

10.7; Near Hope, Cascade 
Mountains, British Co- 



Varying Hare or White Rabbit. 

(PI. VI, figs. 1. 4.) 

Lepus americanus Erxlebeu, Syst. Reg. Anirn., pp. 330-331, 1777. Description 
based on specimens from district about Forts Severn and Cburcbill on 
western coast of Hudson Bay, Keewatin, Canada. No definite type. Fort 
Severn can be considered tbe type locality. 

Lepus hudsonius Pallas, Glires, p. 30, 1778. No type nor locality mentioned, 
but name and context place it here. 

Lepus nanus Scbreber, Siiugth., IV, pp. 880-885, PI. CCXXXIVB, 1790 (in 
part). A composite of Lepus americanus and Sylvilagus floridanus. No 
type nor type locality. Range given from Hudson Bay to Florida. 

Geographic distribution. — Region about southern end of Hudson 
Bay, including southern Keewatin ; southeastern Mackenzie ; most of 
Saskatchewan; Manitoba; east through northern Ontario (including 
Isle Royale and Michipicoten Island, Lake Superior) ; northern 
Quebec; all of Ungava except extreme northern part; Labrador; 
south in the United States in all of Michigan north of Saginaw (ex- 
cept western half of northern peninsula), and west in an isolated 
colony on the Bighorn Mountains, Wyoming. Vertical range, from 
sea level at Hudson Bay to about 2,000 feet near Lake Superior and 
10,000 feet in the Bighorn Mountains of Wyoming; zonal range, 
mainly Canadian. 

General characters. — Upperparts dusky grayish or grayish brown, 
much duller and less rusty or ochraceous than virginianus ; size 
smaller and skull much smaller and more delicately proportioned, 
with rostrum shorter aud proportionately broader at base. 

Color in summer pelage. — Top of head dusky yellowish brown; 
sides of head, especially about eyes, a clearer shade varying from 
dull cinnamon buffy to dull buffy; upperparts of body varying from 
dusky grayish brown to dusky buffy brown ; in typical specimens 
usually grayer and less dingy yellowish than top of head; intergrades 
with virginianus often have body nearly or quite as yellowish brown 
as top of head; middle of back more or less strongly washed with 
black, often forming an indistinct blackish band along middle ; sides 
of body less washed with black and grayer or paler yellowish brown; 
rump a little more heavily washed with black than rest of back ; top 
of tail black ; underside of tail white ; front of fore legs and tops of 
fore feet much like top of head and more rusty yellowish brown than 
body ; outside of hind legs with a band of buffy or ochraceous buffy 
along front (next white underparts) and shading off into dull tawny 
brown; tops of hind feet dull ochraceous buffy varying to dingy 
white ; nape dull dusky gray or dusky brown ; basal half of ears on 


front of outside like top of head and becoming more dusky toward 
tip ; posterior half of outside of ears grayish white becoming blackish 
in a broad border about tip, the black border sometimes extending 
entirely around tip of ears on outside; inside of ears grayish, nar- 
rowly edged all around with white ; underside of neck dull cinnamon 
varying through various shades of buffy cinnamon; underside of 
head and middle of abdomen white ; sides of abdomen often more or 
less encroached on by color of flanks; underfur in summer dull dark 
buffy brown, with plumbeous basal zone sometimes broader than the 
terminal one ; underfur in winter dull dark ochraceous buffy, with a 
basal plumbeous zone of about equal width. 

Immature pelage. — Upperparts buffy brown grizzled with gray. 

Winter pelage. — Pure white, but border of ears about tip slightly 

Skull. — Comparatively small and light with rostrum rather short 
and broad at base; braincase proportionately rather broad and 
rounded, but a little depressed on top; upper outline gently decurv- 
ing posteriorly; frontal area immediately back of base of rostrum 
broad and slightly depressed; supraorbital process small, rather 
short, and tapering irregularly to a blunt point posteriorly, and very 
slightly raised above plane of frontal area ; anterior notch small and 
shallow; posterior notches broad and deep, and skull strongly con- 
stricted and narrow between ; posterior tips of postorbital processes 
standing well out from skull ; zygomatic arch broad and heavy ; mid- 
dle of jugal flat, with a large open pit anteriorly; molar series heavy; 
bulla? small, smooth, and rounded below and in front, but flattened 
and overlaid posteriorly by a rough descending process of the occip- 
ital. In all the forms of this species there is a wide range in the 
form of the skull, especially in the basal width of the rostrum, so 
that only average characters can be given. 

Average measurements {5 adults). — Total length, 470; tail verte- 
bras, 43 ; hind foot, 133 ; ear from notch in dried skin, 62. 

Remarks. — The original description of Lepus americanus was based 
on accounts of Kalni, Barrington, and Forster. Kalm's account is 
a composite of the varying hare and the cottontail of the eastern 
United States, and may be dismissed from consideration. The ac- 
counts of Barrington and Forster were both based on reports and 
specimens collected by the Hudson Bay Company's employees in the 
districts about Fort Severn and Fort Churchill, on the southwestern 
coast of Hudson Bay ; but Fort Severn appears to have been the main 
locality, and this may be considered the type locality for americanus. 
A considerable series of specimens from Pennsylvania north to the 
Arctic coast shows that the dusky grayish brown americanus from 
the southern Hudson Bav region increases in size and richness of 


color to the southward, where two forms, virginianus and struthopus, 
are found in the eastern part of its range. About Hudson Bay and 
adjacent region there is scarcely a trace of rusty or ochraceous shades 
on the body, but in Quebec, Ontario, and Labrador many specimens 
have been examined showing all degrees of intergradation in color. 
South of the St. Lawrence River, however, dusky gray specimens 
like typical americanus are uncommon, and when they do occur their 
large size and heavier skull show their identity with the local forms. 
Over half of the good series from Hamilton Inlet, Labrador, are typi- 
cal americanus in color, while the others are dull ochraceous brown 
closely like strut/wpits. 

To the northwest from the type region there is a gradual increase 
in size and slight darkening in color, forming the subspecies mac- 
fuiUtni of the Mackenzie and upper Yukon region. 

A large series in summer pelage from Isle Royale, Lake Superior, 
and from the northern part of the southern peninsula of Michigan, 
in the Museum of the University of Michigan, are typical americanus, 
without a trace of the ochraceous shade characteristic of virginianus. 
It was most surprising to find that a series of four summer speci- 
mens from the Bighorn Mountains, Wyoming, in the Biological Sur- 
vey collection, is also distinctly referable to americanus and not to 
bairdi. These four specimens are dusky iron gray on the body and 
suffused with dull buffy on the head. The gray of the body averages 
a little paler than in more northern specimens, though now and then 
equaled. Otherwise they appear to be quite typical in size, color, 
and skull. The latter can be matched both in size and shape by 
examples from Fort Chipewyan, Alberta. They have the same 
short and rather broad rostrum, flattened frontal region, and supra- 
orbital processes nearly on a plane with the frontals, instead of being 
raised above it as in most examples of bairdi. The braincase is also, 
like typical americanus, broader and more flattened than in bairdi, 
but the jugals average slenderer and more as in the last form. 

Total number of specimens examined 90, from : 

Wyoming: Bighorn Mountains, 4. 

Michigan: Butter Bridge (Oscoda County), 1; Isle Royale, 33; Luzerne 
(Oscoda County), 2; Marquette, 1; Saginaw County, 1. 

Ontario (Canada): North Bay (Lake Nipissing), 1; Michipicoten Is- 
land, 1. 

Manitoba (Canada): Dog Lake, 1; Sandy Bay, 1. 

Saskatchewan (Canada): Indian Head, 2; Osier, 4. 

Alberta (Canada): Edmonton, 2; 50 miles north of Edmonton, 1; Fort 
Chipewyan, 7 ; Bed Deer, 1 ; South Edmonton, 2. 

Keewatin (Canada): Oxford House, 4. 

Labrador (Canada): Black Bay, 1 ; Hamilton Inlet. 14; Lance au Loup, 1. 

Ungava (Canada) : Forks, near Chimo, 4 ; Fort Chimo, 1. 



Nova Scotia Varying Hare. 

Lepus cmericanus struthoptis Bangs, Proc. Biol. Soc. Washington, XII, pp. 
81-S2, March 24, 1898. Type from Digby, Nova Scotia, Canada ; No. 2025. 
5 ad., Museum of Comparative Zoology (Bangs collection) ; collected by 
Outram Bangs, August 4. 1804. 

Geographic distribution. — Maine, east of Penobscot River, Nova 
Scotia, New Brunswick, eastern Quebec (south of lower St. Lawrence 
and including Magdalen Islands), and Newfoundland. Vertical 
range, from sea level up to over 2,500 feet altitude in New Brunswick; 
zonal range, Canadian. 

General characters. — Size nearly the same as in americanus but ears 
longer; color similar to virginianus but duller and browner; skull 
smaller and slenderer. 

Color in summer pelage. — Top of head and upperparts of body 
cinnamon brown or cinnamon buffy brown, brightest on head and 
darkened with a wash of blackish on back; sides of head deep cinna- 
mon, sometimes around eyes and sides of nose almost deep dull 
ochraceous buffy ; sides of body clearer cinnamon brown than back 
and often becoming rusty or slightly reddish cinnamon brown on 
fore feet and legs, and a duller shade of same along lower border of 
flanks, front of hind legs and tops of hind feet ; front of ears on 
outside similar to top of head, but a black border near tip ; inside 
of ears more or less cinnamon brown or rusty brown with a border 
of same in front and border of whitish posteriorly ; top of tail black- 
ish; underside of neck similar to sides of flanks or a little brighter 
more rusty cinnamon ; rest of underparts white, sometimes with color 
of lower flanks spreading over the borders of abdomen ; underf ur 
dull dark, slightly ochraceous buffy brown underlaid with plumbeous; 
in winter same as virginianus. 

Skull. — Very similar to that of americanus, but averaging a little 
larger with narrower braincase and slenderer rostrum ; slighthy heav- 
ier zygomatic arches and smaller bulla?. Nearer in size to americanus 
than to virginianus, from which it differs in smaller size, narrower 
rostrum, narrower postorbital process, and slenderer jugals. 

Average measurements (5 adults). — Total length, 474; tail verte- 
bra?, 52 ; hind foot, 129 ; ear from notch in dried skin, 66. 

Remarks. — This rather poorly marked subspecies, an intergrade 
between virginianus and americanus, is t}^pical only in Nova Scotia 
and adjacent parts of New Brunswick. Specimens from northern 
New Hampshire and western Maine are similar to strut hopus in their 
small size, but are so richly colored that they must be referred to 
virginianus. Specimens from Lake Edward, Quebec, are much nearer 


to the present form than to americanus, though grading toward the 
latter. The single summer skin from Newfoundland is close to typi- 
cal struthopus in color, but the two winter skins differ in having the 
tops of the feet and ears strongly overlaid or mixed with bright cin- 
namon buff; and the bright cinnamon buff of the underfur on the 
upperparts of head and body is so lightly overlaid with white that 
it shows through and tinges the color of the upperparts even in mid- 
winter. The skulls also differ somewhat from those of typical strut ho- 
pus in having an even slenderer rostrum. Although these animals 
were introduced into Newfoundland from Nova Scotia, they appear 
already on the way to the formation of a distinct subspecies. 

A single specimen in the Carnegie Museum, an adult male in full 
summer pelage, taken on Grosse Isle July 1, 1901, is the only one 
from the Magdalen Islands seen by me. In color it is absolutely 
indistinguishable from typical americanus. The upperparts of the 
body are dusky iron gray, with a wash of blackish along the middle 
of the back and on the rump. The sides of the body are paler ; the 
head and bases of the ears in front are like the back, but are suffused 
with dull ochraceous; the underside of the neck and a line along the 
front of the hind legs are dull, slightly rusty, ochraceous buffy. In 
color this specimen is almost exactly like one in the Biological Survey 
collection from Oxford House, Keewatin, Canada, near the type 
region of americanus. The skull, however, is that of struthopus, to 
which form it must be referred. Mr. Todd, w T ho collected this speci- 
men, writes that he saw many others during the same season, all simi- 
lar to this, but during the summer of 1907 Mr. Osgood spent ten days 
on the Magdalen Islands and, aided by resident hunters, made every 
effort to secure more of these rabbits, without even seeing fresh signs 
of one. The people on the islands informed him that rabbit tracks 
were extremely scarce last winter; so it is apparent that the same 
cause which made varying hares so scarce throughout a large part 
of Canada in 1907 was equally effective on these islands. In July, 
1907, Mr. Osgood obtained four adult topotypes of struthopiis, and it 
was interesting to note that they are much less suffused with dull 
ochraceous, and are thus more dingy grayish brown, than the con- 
siderable series of Nova Scotia specimens of struthopus in the Bangs 
collection, including the series of topotypes. This gives rise to the 
question whether the general coloration of these rabbits may not, as I 
have suspected in the case of other species, vary in different years as 
the result of seasonal climatic differences. 

An August specimen from the Eestigouche River, New Bruns- 
wick, is bleached to a light rusty yellowish color, paler than any 
other example of this form seen. 

Mr. James P. Howley, Director of the Geological Survey of 
Newfoundland, in a letter dated March 23, 1908, writes as follows 


concerning the introduction of Lepus americanus struthopus into 
Newfoundland and its supposed effect on the local abundance of 
Lepus arcticus bangsi: " It is now over forty years since this animal 
[struthopus] was introduced into this country from Nova Scotia. 
It has spread itself all over the island, and is to be found in every 
section of it, especially in the wooded parts. Of course this spread- 
ing was facilitated from the first by sending a few pairs into the 
different districts. The representatives of the districts, aided by 
the government, purchased a few pairs here near St. Johns, where 
they were first turned loose, and distributed them over their several 

" Undoubtedly they have driven out the large Arctic hare [bangsi], 
once fairly plentiful in most parts of the island, but now only to be 
found on the highest and barest uplands, which do not afford food 
or shelter for the rabbit [struthopus]. The former are now quite 

From Outram Bangs the writer learns that the Nova Scotia hare 
was introduced into Newfoundland in 1864 by the late Hon. Stephen 

Total number of specimens examined 69, from: 

Maine: Bucksport, 1; Enfield, 2; Grand Lake, 2. 

New Brunswick (Canada): Artliurette, 1; Forks of Tobique River (Vic- 
toria Comity), 3; Restigouclie River, 1; Tabncintac, 3; Andover, 25. 

Nova Scotia (Canada): Digby, 13; James River, 1; Kings Coimty, 5; 
Shenacadie, 2. 

Newfoundland (Canada): Bay of Islands, 1; Bay of St. George, 2; 
Rantem, 1. 

Prince Edward Island (Canada): Alberton, 1. 

Quebec (Canada): Lake Edward, 4; Magdalen Islands (Grosse Isle), 1. 


Virginia Varying Hare. 

(PL II, figs. 1, 2, 3.) 

Lepus virginianus Harlan, Fauna Americana, pp. 196-19S, 1825. Type from 

Blue Mountains, near Harrisburg, Pennsylvania. 
Lepus wardii Schiuz, Das Tbierreicb, IV, p. 428, 1825. Based on the varying 

bare of soutbern part of tbe United States (Warden, in Stat. Pol. and 

Hist. Account United States, I, p. 233, 1819). 

Lepus borealis Schinz, Syn. Mamm., II. pp. 2S6-287, 1845. No type nor type 

locality mentioned. Distribution given as Virginia and tbe Allegbenies. 

Geographic distribution. — Mountains of West Virginia and Vir- 
ginia north through Maryland, Pennsylvania, New York, New Jersey, 
Delaware, Connecticut, Rhode Island, Massachusetts, Vermont. New 
Hampshire, most of Maine east to Penobscot River and Mount 
Katahdin, and extreme southern Ontario. Vertical range from near 


sea level in Rhode Island up to over 4,000 feet in the Adirondack* 
of New York; zonal range, Canadian. 

General characters. — Largest, and in summer the brightest and 
most richly colored, form of americanus. Upperparts usually some 
shade of rusty ochraceous brown varying in a small percentage of 
specimens to a duller, more buffy brown. Skulls of typical speci- 
mens from Pennsylvania and south average distinctly larger and 
more massive than those from farther north, where they grade into 
the smaller americanus and struthopus. 

Color of summer pelage. — Entire upperparts of head and body 
nearly uniform dull rusty brown or ochraceous brown, varying to 
buffy brown, always more or less darkened by a wash of black, 
heaviest on the back; legs and feet commonly clearer and brighter 
rusty than body, and often clear bright rusty rufous, but like ears 
are mingled whitish and rusty later in spring and earlier in fall 
than body; ears on basal half in front like head, but becoming 
darker brownish or even blackish on terminal half; posterior half 
of ears on outside whitish or gray, changing to a more or less well- 
marked blackish border about tip ; inside grayish with grayer border 
in front and pure white border along posterior margin; a dusky 
margin sometimes present on terminal fourth of anterior border; 
nape similar to back but duller; rump rather more heavily washed 
with black than back ; top of tail blackish or dusky brown, underside 
white or grayish; underside of neck and a narrow line along lower 
border of flanks and legs very rich bright dusky rufous, clearer and 
brighter than back, and always brighter and more rusty than upper- 
parts, even in the duller colored specimens; rest of underparts pure 
white ; underfur rich dark ochraceous buffy underlaid with an equal 
basal zone of plumbeous. 

Winter pelage. — In southern part of their range sometimes pure 
white with a little dusky about tips of ears, but commonly with more 
or less dull rusty brownish on feet and terminal half of ears; the 
surface layer of white over back rather thinner than in americanus ; 
underfur dark buffy or dull rusty ochraceous buffy underlaid with a 
plumbeous zone of about equal width. 

Skull. — Much larger and more massive than in either americanus 
or struthopus ; braincase more rounded and upper outline of entire 
skull more arched; curve over braincase more abruptly descending 
posteriorly; upper outline of rostrum more curved than in ameri- 
canus and frontal area less depressed; supraorbital process similar, 
with the same small notch anteriorly and broad, deep notch poste- 
riorly; posterior process varying from a heavy strap-shaped to a 
roughly triangular form; zygomatic arch and underparts of skull, 
including bullae, proportionately about as in americanus; as in latter, 
breadth of rostrum varies greatly, and one specimen from Gold, Penn- 


sylvania, remarkable for great breadth and massive proportions of 
rostrum; in some individuals upper outline of rostrum nearly 
straight, while more or less strongly curved in most others. 

The accompanying cut of three adult skulls from Gold, Pennsyl- 
vania, shows the great amount of individual variation even in a 
single locality, and demonstrates the difficulty of finding definite 
characters for descriptive purposes. Throughout the group the skull 
characters available are merely averages, subject to much variation 
individually as well as locally. 

Average measurements (5 adults). — Total length, 518; tail verte- 
brae, 49 ; hind foot, 141 ; ear from notch in dried skin, 66. 

Remarks. — This is the brightest colored and most rufous of all the 
subspecies of americanus, but there is great variation in the exact 
shade, and some are much duller and more bufTy brown than others. 
The material in summer pelage at hand from the southern part of its 
range is scanty, but appears to be quite uniform with the large series 
from central New York. The change of coat from summer to winter, 
or the reverse, furnishes much curious variation, some of which little 
resembles either of the full pelages. Specimens collected near 
Ossipee, central New Hampshire, the last of September, are still 
in full summer pelage, but in others collected the middle of October 
the feet and ears are nearly white. 

A few faded specimens in summer coat from central Xew York 
are dull buffy brown almost like phceonofais and in marked contrast 
with the great majority of the large series of richer and darker speci- 
mens from that vicinity. Specimens from the central part of New 
Hampshire and from various points in Maine as far east as the 
Penobscot Eiver and Mount Katahdin are nearly all bright ochra- 
ceous rusty on the feet and upperparts, and thus must be classed with 
virginianus, although the skulls are small and slender, closely like 
typical sti'titliopus. A number of specimens from this intergrading 
region are dull colored like struthopus, just as a few specimens among 
the large series from northern New York are colored like u/nericani/s. 

Total number of specimens examined 146, from : 

West Virginia: Travelers Repose, 1. 

Maryland: Cumberland, 1. 

Pennsylvania: Austin, 2; Bell Landing, 3; Southern part Bradford 

County, 2 ; Center County, 1 ; Erie, 1 ; Gold, 4 ; Gouldsboro, 4 ; Lopez, 

3; Montrose, 1; Pabst Mountain (Lycoming County), 1. 
New York: Big Moose Lake. 1; Catskill Mountains, 2; Elizabeth, 1; 

Elizabethtown, 1 ; Lake George, 7 ; Locust Grove, 2 ; Lyonsdale, 1 ; 

Owego, 1; Peterboro, 1; Piseco, 11; Spruce Lake (Hamilton County), 

14; T Lake (Hamilton County), 1. 
Rhode Island: Exeter, 1; Washington County, 9. 
Massachusetts: Concord, 1; Lunenburg, 7; Middleboro, 3. 
Vermont: Hartland, 10; Rutland, 10; Sherburne, 1. 


New Hampshire: Ossipee, 14; Webster, 2. 

Maine: Bethel, 1; Greenville, 8; King and Bartlett Lake (60 miles south 

of Rangeley Lakes), 2; Mount Katahdin, 1; Sandy Stream Pond, 2; 

Sebec Lake, 1; Upton, 2. 
Ontario (Canada): Bobcaygeon, 2; Mount Forest (east of Lake Huron), 2. 

Minnesota Varying Hare. 

Lepus americanus pliceonotus Allen, Bull. Am. Mus. Nat. Hist., N. Y., XII, Art. 
II, p. 11, March 4, 1899. Type from Hallock, Kittson County, Minnesota; 
No. f ItH, $ ad -> American Museum of Natural History ; collected by E. A. 
Mearns, November 17, 1891 (in changing pelage). 

Geographic distribution. — Western half of northern peninsula of 
Michigan, northern Wisconsin, northern Minnesota, and north into 
extreme western Ontario, and southern Manitoba. Vertical range 
from about 000 to 2,000 feet in northern peninsula of Michigan ; zonal 
range, Canadian. 

General characters. — Size of typical americanus, but in summer 
paler and more buffy ; more like columbiensis in the light buffy color, 
but darker, less yellowish, and often tinged slightly with dull reddish. 

Color in summer pelage. — Top of head and back dull buffy, vary- 
ing to pale dull ochraceous buffy brown, darkest on head, and top of 
back only slightly darker than sides of body; rump slightly more 
washed with black than back ; top of tail mixed black and dingy white 
(sometimes more or less buffy, as in type), giving a dusky grayish 
or buffy gray color; below white; sides of head, especially about eyes 
and back to base of ears, richer, clearer, and more ochraceous buffy 
than back; tops of fore feet and fore legs similar to head, but deeper 
rusty ochraceous buffy, finely grizzled and darkened with dusky; 
tops of hind feet white in all specimens seen ; front of ears like top 
of head on basal half, becoming darker toward tip, where bordered 
with black ; posterior half whitish with a broad black margin ; inside 
of ears grayish, with dull ochraceous buffy margin in front and white 
margin posteriorly; underside of neck varies from dark fulvous 
buffy to rusty cinnamon and deep rich cinnamon rufous; rest of 
underparts bright white, except where color of sides sometimes 
encroaches on sides of abdomen; underfur in summer nearly as in 
americanus, but averaging lighter buffy brownish, sometimes becom- 
ing more or less tinged with cinnamon on top, with the same basal 
zone of rather dark plumbeous. 

Winter pelage. — Entirely pure white except a well-marked black- 
ish border about tips of ears and sometimes more or less brownish 
buffy on front of same; underfur tipped with a broad band of dark 
rusty ochraceous varying to rich cinnamon, similar to virginianus, 


with a basal zone of plumbeous; the ochraceous buffy surface of 
underfur overlaid by such a thin outer coat of white that it shows 
through strongly whenever the overlying white is even slightly 

Immature pelage. — General color dull buffy brownish, thinly griz- 
zled with gray. 

Skull. — Small and rather light ; scarcely distinguishable from that 
of typical americanus, but rostrum averaging a little broader and 
heavier and braincase slightly broader; the same small supraorbitals 
with deep, narrow, well-marked, slit-like anterior notch and rather 
short, irregular postorbital process. 

Average measurements (5 adults). — Total length, 464; tail verte- 
bra*, 35.4 ; hind foot, 137 ; ear from notch in dried skin, 62. 

Remarks. — The present form, while strikingly different from vir- 
ginianus in its pale, dull colors, is far less distinct from americanus. 
though distinctly paler in the southern part of its range. Specimens 
from the southern part of its range in Minnesota are palest and most 
strongly marked, while those from the type locality to the north 
are darker and browner and intergrade with americanus. It is purely 
a color form, and there appear to be no distinctive skull or other 
characters to separate it from americanus. Its range is extremely 
restricted, and more material is needed to show its relationship with 

The type is a young adult in mixed pelage changing from summer 
to winter coat, with feet, ears, rump, and lower flanks nearly all white. 
The rest of the back is dark rusty cinnamon brown like several 
Manitoba specimens. The type skull, that of a young of the year, 
is much mailer and lighter than average adult skulls of this form. 
Specimens from the Porcupine Mountains and elsewhere in the west- 
ern half of the northern peninsula of Michigan show gradation 
toward american us, but are referable to phceonotus. A summer adult 
from Red River Settlement (= Winnipeg) has the color of ameri- 
canus, but the prevailing form along the southern border of Manitoba 
is phceonotus. 

Total number of specimens examined 66, from : 

Michigan: Houghton, 1; Porcupine Mountains (Ontonagon County), 2; 
Pine Lake (Marquette County), 1. 

Wisconsin: Eagle River, 5; Fisher Lake (Iron County), 1; Rhinelander, 
5; St. Croix River (Douglas County), 1. 

Minnesota: Argyle, 1; Bridgrnan, 1; Elk River, 21; Hallock (Kittson 
County), 3; Hinckley, 1; Moores Lake (Todd County), 3: Mora 
(Kanabec County), 1; St. Vincent. 2; Warren, 1. 

Ontario (Canada): Rainy Lake, 1; Rat Portage (Lake of the Woods), 4. 

Manitoba (Canada): Carberry, 5; Red River Settlement, 2; Selkirk Set- 
tlement, 4. 



Turtle Mountain Snowshoe Rabbit. 

Lepus bishopi Allen, Bull. Am. Mils. Nat. Hist., N, Y., XII, Art. II, pp. 11-12, 
March 4, 1899. Type from Mill Lake, Turtle Mountains, North Dakota; 
No. J 9°oW' <$ a( l-> American Museum of Natural History; collected by 
Dr. L. B. Bishop, July 12, 1895. 

Geographic distribution. — Known only from type locality, Turtle 
Mountains, North Dakota. 

General characters. — (The type, in extremely worn summer pelage.) 
Upperparts dark, dull, grayish buffy brown with more or less dull 
ochraceous about head, back, and legs; a narrow dusky dorsal line; 
skull remarkably short and broad. 

Color of the type {and only known specimen, in extremely worn 
summer pelage). — Head dull slightly ochraceous rusty brown, be- 
coming much paler and more of a dull ochraceous buffy from sides 
of nose through orbital region to base of ears; top of head darkest 
and same color extending halfway up front of ears ; latter becoming 
blackish on terminal third and edged all around with whitish; top 
of back similar to top of head, but duller colored and more or less 
clouded or mingled with dull rusty ochraceous buff and with a nar- 
row median band of blackish ; sides of body and rump more of a dull 
grayish brown slightly tinged with dull buffy; tops of fore feet and 
fore legs similar to top of head but a deeper dark rusty ochraceous 
buff; outside of hind legs similar to sides of body but strongly washed 
on outside and in front with ochraceous buffy; tops of hind toes 
rusty ochraceous and rest of feet whitish mixed with same ; upperside 
of tail dusky brown; underside white; underside of neck dark cinna- 
mon brown; rest of underparts pure white; underfur dark slightly 
buffy grayish brown on surface and dark plumbeous at base. 

Skull. — Proportionately the shortest and broadest (especially 
across the braincase) of any member of the americanus group ; ros- 
trum short and broad; frontal area much more strongly depressed 
than in phceonotus or americanus ; braincase full and rounded and 
extraordinarily broad; supraorbitals short and broad with well- 
marked anterior notch and short broad postorbital process stand- 
ing out widely from skull; jugals broad and heavy with a deep 
flat groove anteriorly; posterior end of incisive foramina broadest 
with an angular form to outer posterior corner, as not infrequently 
seen in specimens of bairdi; molar series small ; bulla? about as in 

Remarks. — The type and only known specimen of this form is an 
adult in such badly worn summer pelage that the long outer hairs 
have practically disappeared, leaving the dark woolly underfur ex- 
posed. The general color and such traces of the long hairs as remain 
Nnr.95— No. 29—09 7 


indicate a dark, dull colored animal somewhat like dull brownish 
specimens of typical americanus. The skull, however, is remarkable 
for its short broad form so different from any of the other members 
of the americanus group that it appears advisable for the present to 
recognize bishopi. The type, even though so badly worn, is so dark 
that apparently it is quite a differently colored animal from pha-ono- 
tus. The grayish buffy brown of the underfur is more like ameri- 
canus, but the traces of the surface shades left on head, back, feet, and 
legs indicate that in full summer pelage bishopi may be more dark 
rusty ochraceous than any of the forms mentioned. Further material 
from Turtle Mountains may show this to be a good form or, what is 
still more probable, may prove that the peculiarities of the type are 
due to individual variation, and that the hares from these mountains 
are true americanus. This is rendered more probable by the dis- 
covery that the animals from the Bighorn Mountains of Wyoming 
are not separable from americanus, of Canada. 
Total number of specimens examined 1, from: 

North Dakota: Turtle Mountains, 1. 

Mackenzie Varying Hare. 

Lepus americanus macfarlani Merriam, Proe. Washington Acad. Sci., II, p. 30, 
March 14, 1900. Type from Fort Anderson, north of Great Bear Lake, 
Mackenzie, Canada ; No. 14467, ad. ( skull only ) , U. S. National Museum ; 
collected by R. MacFarlane, March, 1863. 

Lepus saliens Osgood, N. Am. Fauna No. 19, pp. 39^0, October 6, 1900. Type 
from Caribou Crossing, Yukon River, between Lakes Bennett and Tagish; 
No. 98956, $ ad., U. S. National Museum (Biological Survey collection) ; 
collected by W . H. Osgood, June 26, 1899. 

Geographic distribution. — Wooded parts of Alaska, in Upper 
Yukon region, and southwest to Cook Inlet ; base of Alaska Peninsula 
and all of Yukon Territory, western Mackenzie, northern British 
Columbia, and northwestern Alberta, Canada. Its northern limit 
coincides with that of the trees. Vertical range, in the Mackenzie 
Kiver region, from near sea level up to over 2,000 feet altitude; zonal 
range mainly Hudsonian. 

General characters. — Most like typical americanus but darker; 
the darkest and most dusky gray form of this species; upperparts 
of body dusky brownish gray varying to dusky fulvous; head simi- 
lar but strongly suffused on sides with dark ochraceous buff; rump 
blackish; top of tail black. Size averaging distinctly larger and 
ears longer than americanus. 

Color in summer pelage. — Top of back dark brownish gray, vary- 
ing from nearly dark iron gray to dusky cinnamon or dusky buff, 
with an overlying black wash, heaviest along middle, and often form- 


ing a blackish median band; rump more blackish than top of back, 
often nearly black; upper side of tail black; sides of body less heavily 
washed with black and paler than back; head usually more or less 
strongly suffused with dark ochraceous buffy, becoming clearest 
about eyes and grayish on sides of nose; front of ears on basal half 
like top of head, shading into blackish on terminal half; posterior 
half of outside of ears grayish white with a broad blackish band 
next the narrow pure white posterior edging; inside of ears dusky 
brownish, becoming darkest on posterior part and bordered with 
grayish in front and white posteriorly ; front feet and legs and hind 
feet and lower hind legs pure white; underside of neck varies from 
deep rich fawn color to dull dark cinnamon and dull grayish buffy; 
color of flanks encroaching on sides of abdomen in some specimens 
but otherwise rest of underparts pure white; underfur dull ochra- 
ceous buffy underlaid with an equal zone of plumbeous. 

Post juvenal pelage (young of the year). — Upperparts usually a 
shade of dull buffy brown, always with much less black on back and 
rump than in adults, giving the back and sides of body a nearly 
uniform color; tops of fore and hind feet and legs always dark 
colored, varying from rusty cinnamon or rusty ochraceous to dull 
dark buffy. 

Winter pelage. — Pure white, except a narrow dusky margin about 
tips of ears; underfur in winter dingy ochraceous buff as in ameri- 
canus; overlying white coat heavier than in virginianus. 

Skull. — Closely like that of typical a?nericanus, but averaging 
larger with usually larger bullre and jugals. 

Average measurements (5 adults). — Total length, 489; tail verte- 
bra?, 42 ; hind foot, 147 ; ear from notch in dried skin, 67. 

Remarks. — This is a poorly marked subspecies distinguished only 
by its larger size and rather darker colors. There is the usual wide 
range of individual variation in the summer pelage, some specimens 
being dark iron gray while others are dark cinnamon buffy, but the 
prevailing duskiness is an average character separating this from the 
other forms. One specimen from Fort Anderson, Mackenzie, is not 
distinguishable in color from a Lepus bairdi from Mullan, Idaho, 
except for the larger amount of white on the legs and of gray about 
the bases of the ears. Other specimens from Alaska and Yukon Ter- 
ritory are scarcely distinguishable in color from summer specimens of 
bairdi from the type region in Wyoming, but may be separated by 
their skull characters. 

The considerable series of summer specimens from the upper 
Yukon and its tributaries (representing saliens) average a little 
larger than those from either the type region of dalli or macfarlani 
with no color differences to separate them from macfarlani so far as 


the series from the type region of the latter show. After careful 
consideration of the present material it appears best to recognize both 
macfarlani and dalli, though the former is a poorly marked form 
characterized mainly by its slightly darker color and larger size. 
Macfarlani reaches its greatest development about the headwaters of 
the Yukon, whence come the largest specimens examined. 

A small series of summer skins from Tyonek, Cook Inlet, Alaska, 
are similar to those from the Yukon and Mackenzie rivers. 

Four summer specimens in postjuvenal pelage from Lake Clark, 
only a short distance from Cook Inlet, have the body dusky brownish 
gray with a dingy rusty yellowish tinge, the tops of the fore feet and 
legs dark rusty cinnamon and the tops of the hind feet a slightly 
lighter shade of the same. There are no marked skull characters in 
the specimens from Lake Clark, but the rostrum appears to be more 
slender and the supraorbitals rather smaller than typical macfarlani 
and more like dalli, and it is possible they may represent the latter 
form. Specimens from Fort Resolution and Fort Rae, on Great 
Slave Lake, Mackenzie, are intermediates between americanus and 

Total number of specimens examined 345, from: 

Mackenzie (Canada) : Fort Anderson, 4 ; Fort Franklin, 5 ; Fort Laird, 7 ; 
Fort Providence, 1 ; Fort Rae, 5 ; Fort Resolution, 4 ; Fort Simpson, 
43; Fort Smith, 2; Great Bear Lake, 1; Mount Charles (Great Bear 
River), 9; Nahanni, 1; Old Fort Good Hope, 3; Peel River, 1. 

Yukon (Canada) : Caribou Crossing, 1 ; Fort Selkirk, 6 ; Forty Mile, 2 ; 
Lake Le Barge, 1 ; La Pierre House, 1 ; Macmillan River, 4 ; Pelly 
River, 189; Russell Mountains, 1; Thirty Mile River (15 miles north 
of lower Lake Le Barge), 2. 

British Columbia (Canada): Bennett, 4. 

Alaska: Mouth of Charlie Creek, 4; Circle, 2; Tyonek (Cook Inlet), (5; 
15 miles below Eagle, 1 ; Fort Yukon, 5 ; Lake Clark, 17 ; head of 
Seward Creek (near Eagle), 7; Mount McKinley (north base), 4; 
Sheep Creek, 2 ; mouth of Porcupine River, 2. 


Alaska Varying Hare. 

Lepus amcricanus dalli Merriam, Proc. Washington Acad. Sci., II, pp. 29-30, 
March 14, 1900. Type from Nulato, Alaska; No.ffff, $ ad. (skull only), 
U. S. National Museum ; collected by W. H. Dall, January 27, 1867. 

Geographic distribution. — Wooded parts of western Alaska from 
below Fort Yukon to coast of Bering Sea at mouth of Yukon, and 
from Bristol Bay north to tree limit. Vertical range from near sea 
level on lower Yukon up to about 2,000 feet on adjacent mountains; 
zonal range mainly Hudsonian. 


General characters. — Size about as in macfarlani, from which it 
differs strikingly in its ochraceous buffy summer pelage and the more 
pointed and rounded rostrum. 

Color in, summer pelage. — Upperparts of head and body dark 
ochraceous buffy, darkened on top of back and paler and brighter on 
sides of head and neck; upperparts grizzled with grayish buffy; 
underside of neck nearly clear dull ochraceous buffy; rest of under- 
pays with fore and hind feet white; underfur on top of back tipped 
with a thin zone of dusky brownish, underlaid with a stronger and 
broader zone of dark ochraceous buffy followed by a broad basal zone 
of plumbeous; the ochaceous buffy zone of underfu