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No. 8 ^ ^^>:,^,^ ..*^ 


[Aftitiil (late of pnhlication, .Tannary 31, 1895] 



OF iiii: 

Family <iJKOIflHI>JG 

(Exclusive of the species of Thomomys) 






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^^ 3 ■ ^ 


No. 8 


[Actual date of publicatiou, January 31, 1895] 



Family CJKO.^IYIDtE 

(Exclusive of the species of Thomomya) 

15 Y 





U. S. Department of Agriculture, 

Washington, D. C, September J26, 1894. 
Sir : 1 have the honor to transmit herewith, as No. 8 of North Ameri- 
can Fauna, a Monograi^hic Kevision of the Family Geomyida', exchisive 
of the species of Thomomys. 

In preparing a bulletin on the economic relations of the Pocket 
Gophers it became necessary to determine the status and geographic 
distribution of the various forms. This study developed the fact that 
the group was sorely in need of technical revision. The present paper 
is the outgrowth of an attempt at such a revision. It has grown so far 
beyond the limits originally intended that a large genus {Thomomys) has 
been of necessity omitted and will form the subject of a subsequent 

The results of the economic study of the group will appear as a sepa- 
rate bulletin prepared by my assistant, Mr. Vernon Bailey. 

C. Hart Merriam, 

Chief of Division of 
Ornithology and Mammalogy. 

Hon. Chas. W. Dabney, Jr., 

Acting Secretary of Agriculture. 




Material studied 11 

AcknowJedgnieuts 12 

Illustrations 12 


Adaptation to a subterranean life 15 

Progression backward as well as forward 16 

The tail an organ of touch 16 

Normal position of the fore feet 17 

Division of the mouth into two chambers 17 

The tongue 18 

The cheek pouches 18 

How food is put into the cheek pouches 18 

Th c f oo d 19 

Color phases 19 

Sexual variation 20 

Individual variation 21 

Subdivisions of the family Geomyida^ 22 

Key to the genera 23 

Phylogenetic tree of the genera 24 

List of the genera and species 25 

Ccograi>hic distribution of the family and genera 26 

Number and distribution of the species 27 

The United States species 28 

Distribution of the Mexican species 30 

Weight of characters 32 

List of specimens examined 33 


The cranium as a whole 33 

The individual bones 40 

Changes with age 61 

Coi'ssification of the paired bones 63 

Cranial variations — departures from the trunk line 63 



Incisors 70 

Premolars 72 

Molars 74 

Variation in form of m^ 76 



Arrangement of the enamel 78 

Principal divisions indicated by the enamel plates 79 

Normal number of enamel plates 79 

Variation in enamel plates of m^ 79 

Characters of the unworn teeth 83 

Incisors 83 

Deciduous premolars 83 

Permanent premolars 84 

Molars 85 

Summary 85 

Changes in form and enamel pattern of young teeth with wear 86 

The enamel organ 87 

The osteodentine 87 


Manner of attachment of the teeth 88 

Dynamics of the incisors 89 

Dynamics of the molariform teeth 90 

(a) Manner of implantation and curvatures 90 

(6) Influence of the direction of the jaw movement on the molariform teeth. 92 

(1) Effect on the size and curvature of the jirisms 92 

(2) Eftect on the proportions of the prisms 93 

(3) Ertect on the enamel plates 93 

Arrangement and mode of operation of the cutting blades 93 

(a) Dominant movement of jaw obliquely transverse 93 

(6) Dominant movement of jaw antero-posterior 96 

Treatment and course of food 98 

Muscles that operate the cutting machine 98 

Muscles of the cheek pouches 101 

Muscles connecting the head with the neck 102 

Aualj'sis of jaw movements 102 

Influence of the masseter muscle in molding the skull and modifying the 

teeth 104 

Efl'ects on the skull 105 

Ett'ects on the teeth 106 



Geumys 109 

Pappogtomys 145 

CyatoyeumijH 149 

Plati/yeomys 162 

Orthogeomys 171 

Heterogeoiiiy^ 179 

Macrogeoinys 185 

Zygogcomys 195 

Thomomys 198 



1. Of the species of Geomys 202 

2. Of the species of Cratogeomya 203 

3. Of the species of Platygeontys, Orthogeomys, Ueterogeomya, Pappogeomys, and 

Zygogeomys 203 



Table A. Of Geomijs hiirsarius, lufesceiis, hreviceps, sagittaUs, and attwateri .. 204 

B. Of Geomys personatus, faUax, iexensis, and areiiariits 206 

C. Of Geomys tuza, floridanus, mobilensis, and Zygogeomys trichopud ..... . 208 

D. Of the species of Cratogeomys 210 

£. Of the species of Platygeomys 212 

F. Of thespeciesot' Pappogeomys, Orthogeomys, Macrogeon>ys,audHetero- 

geomys ......;.;......;... ^ ^ .. i . i ;...;.;; 214 



Frontispiece, Geomys tuza (Ord). 

1. Skull of Geomys biirsarius. 

2. Slvull of Cratogeomys mcrriaiiiL 

3. Slcull of Platygeomys gymiiuriis. 
4 SknU of Heterogeomyshitifidiis. 

5. Skull of Macrogeomys dolicliocephahts, 

6. Skull of Zygogeomys trichopns. 

7. Skulls of Geomys tuza, mobilensis, and floridanus. 

8. Skulls of Cratogeomys oreocetes, j)ercgrinns, estor, and perotevsis. 

9. Skulls of Geonii/s arenarius, iexensis, attwateri, sagittalis, liitescens, hrevicejys, and 


10. Lower jaws of Geomys tuza, floridanus, mobilensis, bursarius, Cratogeomys oreocetes, 

peregrinus, merriami; Macrogeomys dolichoceplialus, and Platygeomys gymnurns. 

11. Skulls of Pappogeomys huUeri, Macrogeomys heterodns, vostaricensis, Platygeomys 

fumosus, Orthogeomys latifrons. 

12. Skulls of Cratogeomys castanops, fulvescens, and Geomys personatus. 

13. Left zygoma, showing variations in jugal bone in the various genera and species. 

14. Palatopterygoids, showing variations in the various genera and species. 

15. Skulls of Macrogeomys cherriei and Helerogeomys torridus. Occiput of Macrogeomys 

dolichoceplialus, Heterogeomys hispidus, Platygeomys bulleri, Cratogeomys merriami, 
Platygeomys gymnurns. Uiiper incisors of Macrogeomys dolichocephalus, Crato- 
geomys merriami, Zygogeomys trichopns, Geomys bursarius and tuza. 

16. Molariform teeth. Heterogeomys torridus, young, showing deciduous premolar in 

situ; also upper permanent premolar showing unworn enamel cap; also same 
showing permanent enamel pattern. 

Geomys bursarius, showing deciduous premolar in situ; also crowns of molari- 
form series showing permanent enamel ])attern. 

Macrogeomys lieterodus, right upper ijremolar of adult. 

Zygogeomys trichopns, crowns of molariform series showing permanent enamel 

Cratogeomys castanops, enamel pattern of molar crowns in young and adult. 

Macrogeomys cherriei, young crowns of molariform series, showing permanent 
enamel pattern. 

17. Skulls seen from above: vault of cranium cut away, showing floor of brain case 

■ in — 

Heterogeomys torridus, Zygogeomys trichopus, Geomys bursarius, Platygeomys gymnu- 
rus, and Cratogeomys merriami. 

18. Vertical median longitudinal section of skull (mesethmoid and right half of 

vomer in place) — 
Geomys bursarius, Zygogeomys trichopus, Heterogeomys torridus, Cratogeomys mer- 
riami, and Platygeomys gymnnrus. 

19. Orthogeomys scalops 9 ad- skull from above, and base of cranium. Median longi- 

tudinal section of nasal chamber (vomer and mesethmoid removed) showing 
turbinated bones in — 
Geomys bursarius, Zygogeomys trichopns, Heteroqeomys torridus, Cratogeomys mer- 
riami, Platygeomys gymnurus. 



1. Face of Oeomj/s bursarius, showing grooved upper incisors and openings of cheek 


2. Face of Thomomjis talpoUJcs, showing phmo uppei' incisors and openings of cheek 


3. Left fore foot of Geomyii personatua, s\\ov,i\\g the rows of bristles which form 

brushes on the sides of the toes. 

4. Side view of skull of Cratogcomiis merriami (zygoma sawed off). 

5. Basioccipital of Cratogeomtjs merriami. showing difference in form of upper and 

lower surfaces (ankylosed exoccipitals shown also). 

6. Variations in interparietal: Plnfi/ficimiis tiilorlnnna (showing changes with age); 

Geomys tii:a ^ ad. (Augusta, (ia.); G. mobilensis J yg. ad. and ^ old (Milton, 
Fla.). All natural si/e. 

7. Longitudinal vertical median section of skull of Cratofjeomijs merriami, showing 

interior of brain case and nasal chamber. Vomer and mesethmoid in place. 

8. Very young skull of Geomys bursarius from Elk River, Minnesota. Upper sur- 

face, showing troutals ankylosed togetlier, and interparietal inseparable from 

9. Young skull of Cratofjeomys merriami, vault of cranium cut away to show floor of 

brain case. 

10. Vertical median section of front part of skull of Geomys bitrsarins, showing tur- 

binated bones, etc. (mesethmoid and vomer removed). 

11. Principal types of pa.latoi)terygoids. 

12. Inferior surface of young skull of Craiocjeomys merriami. 

13. Longitudinal vertical section of nasal chamber of Cratogeomys merriami, showing 

vomerine sheath (vomer rcnu)ved). 

14. Jugals (showing principal types of form). 

15. Three skulls of Zygogeomys trivhopus, showing changes wiih age. 

16. Very young skull of Heterogeomys torridiis from Motzorongo, Vera Cruz. 

17. Types of frontal: (1) Cratogeomys merriami, (2) Ilelerogcomys torridits, (3) Macro- 

(/eomys heierodns, (4) Vrthoijeomys sealops. 

18. Outline of skull of Platygeomys gyr/Diurxs, slunviug teeth in situ. 

19. Incisors of Platygeomys gymnnru^ sein from behind. 

20. Cross section of upjicr incisor in (1) Macroiieomys doliclincephalns; (2) Heterogeo- 

mys Itispidiis; (3) M.coslariceiisis; (4) M. vherriei (showing enamel face and sin- 
gle sulcus). 

21. Cross section of upper incisor in (1) Cratogeomys merriami ; (2) Platygeomys (jym- 

nnriis; (3) Cratogeomys perote)isis ; (4) J'appogeomys htiUeri. 

22. Cross section of upjier incisor in bisulcate series: (1) Zygogeomys triclioptis; (2) 

Geomys hitrsari)is ; (3) Geontys iuza. 

23. Cross section of upper incisor of Thomomys doiiglasi, showing shallow sulcus close 

to inner side of tooth. 

24. Cross section of lower incisor of Cratogeomys merriami. 

25. Crowns of upper and lower premolars of Macrogeomys dolichoeephalus. 

26. Types of molariform teeth seen in profile: (1) Heterogeomys hispidns ; (2) Crato- 

geomys merriami ; (3) Geomys tnza. 

27. Principal types of crown pattern of m': (1) Geomys brericeps ; (2) Pappogeomys 

huJleri; (3) Platygeomys gymiiurns : (4) Cratogeomys estor : (5) Zygogeomys tricho- 
pus ; (6) Macrogeomys dolichoeephalus ; (7) Macrogeomys heterodas. 

28. Variations in crown pattern of m^ in Cratogeomys fidveseens. 

29. Variations in crown patteru of m^ in Cratogeomys castaiwps. 

30. Types of enamel pattern of upper premolar : (1) Cratogeomys merriami ; (2) Hetero- 

geomys hispidus. 

31. Types of enamel pattern of u])per molariform teetli in the different groups: (1) 

Geomys bursarius; (2) Cratogeomys caxlauops; (3) Zygogeomys trichopus; (4) 
Macrogeomys cherriei ; (5) Thomomys hulhirorus. 

32. Types of enamel pattern of lower molariform teeth: (a) Geo7nys bursarius; (b) 

Thomomys bulbirorus. Except in Thomomys tlie enamel pattern is the same 
throughout the family. 

33. Types of enamel pattern of crown of ni' in the restricted genus Geomys. 

.34. Types of enamel pattern of crown of m ■ in the several groups in which this tooth 
is a double prism. 

35. Variations in form of crown and enamel pattern of m^ in Plattigeomys and Crato- 

geomys merriami. 

36. Molariform teeth of a A'ery y(Ming Geomys bursarius. showing deciduous and per- 

manent premolars in situ, and unworn crown of m' which has not yet reached 
plane of crowns of other teeth. 

37. Right lower unworn permanent \^xemoh\x oi Heterogeomys torridus: (1) inner or 

lingual side;- (2) enamel cap from above. 


ZS. Right last lowci' molar of Hctcror/eomiiK forridns, showing mi worn euamelcap and 
rchitioiis oi' enamel and dentine lower down. 

3D. Transverse section of skull of J'ttitjif/eomi/s gijmnnriis, showing manner of implan- 
tation an I r(dations of molariform teeth. 

40. Upper and lower molars of I'lati/gcoiinis </!i)tniunts in normal position, showing 

angle of trnneation of crowns necessitating lateral movement in arc of circle. 

41. Cross section of mandible of ridtiif/eovii/s (jymnurns, showing how roots of lUj and 

■m:i straddle the incisor. 

42. Profile view of lower premolar in Ma(ro(jromiis dolivhocephalus and PJatijgeomys 


43. Longitndinal section of molariform teeth of Plati/ficonn/s {lymnurus (diagram- 


44. Crowns of molariform teeth of riaii/neomijs i/jjmnitrxs. 

45. Snperimposed molar series of Platiigeomijs (jymnurns, showing relations of enamel 

4l!. Longitudinal section of molariform teeth of Macrof/eomys dolichoceplialus (dia- 
grammatic. ) 

47. Crowns of molariform teeth of Macroyeo.mys dolicliocephahts. 

48. Superimposed molar series of Alacrofjeomys doHchocephahis. 

49. Siile view of sknll of Macrogeomys doHcltucephahis. 

50. Side view of skull of Platyf/eomyx f/ymnitrits. 

51. Hinder part of sknll of Macrogeomya dolichovephahis from above, showing relations 

of mandible. 
.52. Transverse vertical section of cranium of Macrogeomys dolichocephalns (just in 
front of audita! bulhe) with mandible in place — viewed from behind. 

53. Hinder part of skull of Platygeoiiiys gymnitrus from above, showing relations of 


54. Transverse vertical section of cranium of Platygeomtjs giimnnvus (just in front of 

audital bulLe) with mandible in place — viewed from behind. 

55. Geomys hnrsarius. Side view of skull, zygomatic arch sawed off to show bottom 

of orbit. 

56. Pappogcomys bullcrt $ . Vault of cranium sawed oft", showing floor of brain case. 

From Sierra Nevada de Colima, Mexico. 

57. Pappogeomys biiUeri. Vertical longitudinal section of skull, mesethmoid and 

vomer in place. (Same specimen as 56.) XlA. 

58. Pappogeomys huUeri. . Vertical longitudinal section of skull. Mesethmoid and 

vomer removed to show eudoturbinals. (Same specimen as 56.) Xl^. 

59. Craiogeomys merv'mmi. Crowns of molariform teeth. 

60. Orthogcoiuiis svalojjs. Longitudinal vertical median section of skull. Meseth- 

moid and vomer iu place. From Cerro San Felipe, Oaxaca. Xli. 

61. Orthogcomys scalops. Same specimen with mesethmoid and vomer removed, 

showing eudoturbinals. Xli. 

62. Orthogeomys scalopn. Last upper molar showing divided outer enamel plate. 

63. Orthogeomys velsoni. From Mount Zempoaltepec, Oaxaca, Mexico. Skull from 

above. (Type). 

64. Orthogeomys latifrons (type). Crowns of molariform teeth. 

65. Heterogeomys hispidiis. l''roin Jico, Vera Cruz. 

66. Heterogeomys lorridus. From Motzorougo, Vera Cruz. 

67. Macrogeomys costaricensis and cherriei, showing differences in jugal, viewed from 

both sides. 
68,69,70,71. Tliomomys bidbiroriis. 9 From Salem, Oregon. Sectionized skull. 

68. Vertical median longitudinal section; vomer and mesethmoid removed, 

showing turbinated bones. 

69. Same, mesethmoid and vomer in place. 

70. Vault of cranium sawed off, showing floor of brain case. 

71. Anterior part of floor of brain case, much enlarged. 

Map 1. A Distribution of genus Thomomys. 

]i Distribution of genus (ieomys. 
Map 2. Distribution of genus Cratogeomys. 
Map 3. 1 Distribution of genus Pappogeomys. 

2 Distribution of genus Plaiygeomys. 

3 Distribution of genus Zygogeomys. 

4 Distribution of genus Heterogeomys. 

5 Distribution of genus Orthogeomys. 

6 Distribution of genus Macrogeomys. 

Map 4. Distribution of species of Geomys and Cratogeomys 

No. 8. NOETH AMEEIOAN FAUNA. January, 1895. 


By Dr. C. Hart Merriam. 


The present paper is based on a study of the rich collection of Pocket 
Gophers belonging to the U. S. Department of Agriculture, comprising 
upwards of 800 specimens, exclusive of the genus Thomomys. This 
material has been supplemented by 110 specimens from my private col- 
lection, and a number from the U. S. National Museum,* making a total 
of about a thousand specimens, among which are by far the greater num- 
ber of actual types known to be extant. The Department collection 
contains no less than 200 specimens from Mexico, most of which were 
secured by Mr. E. W. Nelson, a field naturalist of the Division. These, 
together with a few highly interesting sjiecimens from Costa Eica and 
Guatemala in the U. S. National Museum, have enabled me not only 
to bring together for actual comparison all of the species i)reviously 
described, and to add a considerable number heretofore unknown, but 
also to recognize several marked generic types whose existence had 
not been suspected. 

Critical study of this unparalleled wealth of material has led to the 
discovery of some very remarkable dental peculiarities that have been 
deemed worthy of detailed description and illustration. Moreover, the 
opportunity has been utilized to contribute a chapter on the morphol- 
ogy of the skull, which it is hoped will prove of service to those inter- 
ested in the craniology of the Rodentia. 

It is a matter of deep regret that the magnificent series of specimens 
of living forms on which the present paper is based, has not been sup- 
plemented by a single fossil ; and it is earnestly hoped that an oppor- 
tunity may yet be found to study the remains of the extinct animals 
that have been referred to the family — correctly or otherwise — in com- 
parison with the rich collection of living types now in our National 
Museum. If the theory is correct, that the group has attained its 
greatest expansion in the present age, we need not look to the rocks 

* Placed at my disposal by the courtesy of Mr. F. W. True, Curator of Mammals- 



for additioual liiglily diversified types, but only for the links tbat biud 
the several phyla together and connect them with the more primitive 
forms from which they came. These would be of the utmost interest. 

The author is indebted to Mr. F. W. Tiue, Curator of Mammals in 
the U. S. National Museum, for the privilege of describing two species 
from Central America; to Dr. J. A. Allen, of the American Museum 
of Natural History, New York, for the privilege of examining the type 
of Ms Geoniys cherriei; and to Mr. H. P. Attwater, of San Antonio, 
Texas, for the loan of a large series of the subspecies here described 
as Geomi/s brericeps attwateri. The author is under special obligations 
to Mr. Oldfield Thomas, Curator of Mammals in the British Museum, 
and to Dr. Paul Matschie, of the Eoyal Museum of Natural History in 
Berlin. Mr. Thomas has kindly compared specimens sent him for that 
purpose with his own types in the British Museum, and has also con- 
tributed measurements and other details of importance. Dr. Matschie 
has been good enough to remeasure the original types of Peters' 
Geomys heterodus and Lichtenstein's Geomys mexicanus, which speci- 
mens are still extant in the Berlin Museum, and has further taken the 
trouble to prepare and send me a table of cranial measurements of the 
skulls of these same types, with much other information of importance 
respecting them. And Dr. F. A. Jentink, the able director of the 
Leiden Museum, has done me the favor to send additional particulars 
about the Bullock specimen of Geomys hursarius, still extant in the 
Leiden Museum, which specimen has given rise to much controversy 
and is supposed to be Shaw's original type of the species. 

From time to time during the preparation of the work, collectors 
have been sent to special localities from which new or supplemental 
material was desired, thus making it possible to settle many points that 
were originally in doubt. Much has been learned respecting the habits 
and mode of life of the animals from a living Geomys Jutescens sent from 
Vernon, Texas, by my field assistant, Mr. J. Alden Loring. This animal 
was kept in confinement until sufiQciently tame to permit handling freely 
and was the means of the discovery of a surprisingly large number of 
interesting facts that otherwise would have escaped detection. 

Respecting the illustrations, the frontispiece was drawn by Mr. C. B. 
Hudson; plate 1 by Mr. Benjamin Mortimer; text figures 1 and 2 by 
Dr. George Marx ; figures 5, 19, 63, 65, and 66 by Dr. James E. McCon- 
nell; and all of the outline camera lucida drawings of teeth by myself. 
Plates 2 to 19, inclusive, and all of the remaining text figures were drawn 
under my constant supervision by Mr. F. Miiller. All of the twenty 
full-page plates have been reproduced by photolithography by Mr. Ber- 
thold Meisel, of Boston, and the text figures, with two or three excep- 
tions, have been electrotyped from the originals by Mr. Harry 0. Jones, 
of New York. 

It will be observed that the generic names engraved on most of the 
plates (pis. 2-6, 8, and 10-16) do not agree with the generic names in the 
text. This misfortune is the result of having the plates printed before 

JAN., 1895.] INTRODUCTION. 13 

the genera were finally segregated. The correct names are given in all 
cases on the explanations facing the plates. 

The literature relating to the group is rarely referred to in the present 
paper, except for original descriptions. The reason is that previous 
papers have been based on insufficient material. To use them at all 
would necessitate a large amount of explanation and criticism without 
corresponding advantage. 

All the measurements in the present paper are in millimeters. 



The family Geomyid(v, comprising the mammals commonly known as 
Pocket Gopliers, is conliued to North America, where it ranges from 
the plains of the Saskatchewan in Can- 
ada southward to Costa Rica. It attains 
its highest development in tlie western 
United States and Mexico, and does not 
inhabit the region east of the Mississippi 
Valley except in the Gulf States, where 
it reaches the Atlantic coast in Florida 
and Georgia, but does not occur north 
of the Savannah River. 

The appearance of a characteristic 
species is well shown in the frontispiece, 
and the peculiar aspect of the face in the 
accompanying cut (tigs. 1 and 2), which 
shows the openings of the cheek pouches, 
wholly outside of the mouth, and also 
the pattern of the upper incisor teeth in 
two of the commonest genera, Oeomys 
and Thomomys. 

All the members of the family spend 
their entire lives underground, and their 
whole organization is modified in accord- 
ance with the needs of a subterranean 
existence. The species, though n numer- 
ous, are very much alike externally. They are short-legged, thickset 
animals, without an appreciable neck, without noticeable external 
ears, and with very small eyes. The feet are largely developed for 
digging. The fore paws in particular are very strong, are armed 
with long curved claws,* and the sides of the toes are lined with 
rows of bristles that evidently serve in preventing the dirt from 

FiG.l. — Faceof Oeomys bur. ■iarius, show- 
ing grooved upper incisors and openings 
of cheek pouches. 

Fi«. 2.— Face of Thomomys talpoides, 
showing plane upper incisors and open- 
ings of cheek pouclies. 

*Tlie relative development of the daws is largely a matter of age and soil. Tbey 
continue to increase in size thronghout the life of the individual; their poiiitw are 
worn off in hard soil so that the claws become thick and hlunt. In sandy soil they 
do not meet enough resistance to ])roduce the usual wear, and, conse(iuentIy, are 
longer and more slender than normal, 




passiug between the fingers (fig. 3), thus completing a more effective 
arrangement for keeping the tunnels clean, and for pushing the earth 
out of the openings in the burrows. The tail, which is of moderate 
length, is thick, fleshy, and usually devoid of hair, and is endowed 
with tactile sensibility. 

The Pocket Gophers, in working their way 
through the earth in the construction of their tun- 
nels, use the j)owerful upper incisors as a pick to 
loosen the ground. At the same time the fore feet 
are kept in active operation, both in digging and in 
pressing the earth back under the body, and the hind 
feet are used also in moving it still further backward. 
When a sufficient quantity has accumulated behind 
the animal, he immediately turns in the burrow and 
by bringing the wrists together under the chin, 
with the palms of the hands held vertically, forces 
himself along by the hind feet, pushing the earth out 
in front. When an opening in the tunnel is reached 
the earth is discharged through it, forming a little 
hillock that resembles in a general way the hills 
thrown up by moles. In many species there is a 
naked callosity or 'nasal pad' over the anterior half 
of the nose, which must be of great assistance in 
the construction of the tunnels. When this callos- 
ity is largely developed the nasal bones underneath are highly arched or 
inflated, as in Heterogcomys hispidus. 


The Geomys lutescem already mentioned from Vernon, Texas, which I 
kept alive for several months, surprised me very much by running back- 
ward as rapidly and easily as forward. This method of progression was 
particularly noticeable when the animal was in his own quarters where 
he could follow a runway or an accustomed route. When carrying 
food to one of his storehouses he rarely turned around, but usually ran 
backward to the j)lace of de^wsit, returning for more, and repeating the 
operation again and again, the to-and-fro movement suggesting a shut- 
tle on its track. The well-known peculiarity of the external genitalia, 
which are so hidden and modified that the sexes are determined with 
difficulty, is doubtless the result of this habit, protecting the parts 
from injury when the animal is moving backward. 


Throughout the family Gcomyidw the tail is rather large and fleshy, 
and as a rule is naked or scantily haired; * it varies in length in the 

* The tail is naked in most of the southern species and is more or less covered with 
hair in the northern species. The latter have much more hair on the tail in winter 
than in Rummer, 

ria. 3. — Left fore foot of 
Geomys personatus, sliow- 
iijg the rows of bristles 
which form brushes on 
the sides of the toes. 

JAN , 1895 


various species from about 65 to 115 mm. The functiou of this pecu- 
liar appendage had long puzzled me, but by watching- the live Geomys 
above mentioned as it ran backward in its runways I saw that it was 
used as an organ of touch. It is doubtless endowed with special tactile 
sensibility and is evidently of great value in warning the animals of 
the presence of an enemy in the rear when they are traveling backward 
in their dark tunnels. So far as I am aware this is the only instance in 
which the tail of a mammal is used for this purpose. 


In walking on soft ground the fore feet are usually held in the nor- 
mal position, with the soles down, or inclined shghtly inward. In 
walking on hard ground, however, the fore feet are turned sideways, 
their soles facing one another, so that the claws curve inward, and the 
animal walks on the outer or ulnar side of the foot. This method of 
using the fore foot in walking on hard substances was frequently 
observed, and enables the animal to walk comfortably where the long 
curved claws would be in the way A held in the normal position. It 
was also frequently noticed that the feet were held in the same jjositioii 
(horizontally) when at rest, and when used as a scoop in pushing loads 
of earth or sand out of the way. When thus engaged the feet were 
drawn back under the breast, the wrists near together and the long 
claws turned outward. By moving the body quickly forward the 
animal always succeeded in throwing ahead of it a considerable quan- 
tity of loose earth. 


The lips and thin furry covering of skin are drawn into the broad 
space between the incisors and molars, where they meet in a raphe on 
the roof of the mouth and then separate again to meet around the under 
jaw, forming a diaphragm-like partition between the incisors and 
molars. The orifice is small and wholly inferior, and may be completely 
closed by the fleshy tongue or by the tailing together of the furry lips, 
leaving a vertical slit between. The raphe or line of union of the lips 
on the roof of the mouth reaches most of the way from the incisors to 
the upper premolars, A narrow band, not covered with fur, connects 
the two lips inferiorly, crossing the floor of the mouth near the pos- 
terior end of the synqihysis of the mandible. Thence the lips — if the 
term lips may be applied to this fold of skin — pass around the lower 
incisors, where the skin is attached posteriorly, so that it may be 
retracted, leaving a bare space below the point where the tooth pro- 
trudes from the alveolus, thus giving greater freedom to the lower 
incisors during tlie act of gnawing. During the to-and-fro drill-like 
motion of the jaw the skin probably remains nearly stationary, while 
the under incisors play rapidly back and forth. The object of the dia- 
7i33— No. 8 2 


phragm-like partition which separates the mouth into two chambers is 
obviously to prevent dirt and chips from entering the mouth proj)er 
during the various subterranean operations of the animal. 


The tongue is short, thick, and fleshy. Its principal function doubt- 
less is to keep the food between the crowns of the teeth during masti- 
cation. At other times it serves as a plug to stop the opening in the 
furry diaphragm between the incisors and molars. 


All of the Pocket Gophers are provided with external cheek pouches, 
which open on the sides of the face outside of the mouth, and are cov- 
ered with fur inside. These cheek pouches are used exclusively in 
carrying food, and not in carting dirt as often erroneously supposed. 
The animals are great hoarders and carry away to their storehouses 
vastly more than they consume. The cheek pouches reach back as far 
as the shoulder and are so attached that they can iiot be completely 
everted without rupture of their connections. While the posterior 
part of the sack is held back by the muscle which stretches thence to 
the lumbar vertebra", the skin of the inner side of the jiouch, which 
covers the side of the face below the eye and in front of the ear, may 
be everted or prolapsed, hanging down as a flap below the corners of 
the mouth. This is probably what happened in the case of snake fright 
observed by Dr. A. K. Fisher at Ellis, Kansas, in June, 1893. Dr. 
Fisher saw a gopher snake {Pituo2)hi.s) about 5 feet in length hunting 
for breakfast. He says: "Presently the snake glided into a gopher 
hole. In a few minutes I saw a gopher {Geoniys lutescens) run out as 
fast as possible from the other end of the line of hills. I soon caught 
up to it. It appeared very much frightened, and its cheek pouches 
were hanging out. The gopher evidently had only scented the snake, 
for it Avas apparent that the snake had not seen the mammal, as it 
came out of the hole by which it entered and glided off deliberately 
in another direction." 


A live Geoniys from Vernon, Texas, has been carefully observed for the 
purpose of ascertaining how the reserve food is placed in the cheek 
pouches. The animal soon became sufficiently tame to eat freely from 
the hand, and was commonly fed bits of potato, of which he was particu- 
larly fond. The manner of eating was peculiar and interesting, and 
showed an ability to use the huge fore feet and claws in a way previously 
unsuspected. After satisfying the immediate demands of hunger it was 
his practice to fill one or both cheek pouclies. His motions were so 
swift that it was exceedinglj^ difficult to follow them with sufficient 
exactness to see just how the operation Avas performed. If a whole 


jiotato was given bim, or apiece too large to go into the pouch, he invari- 
ably grasped it between the fore paws and proceeded to pry off a small 
Iticce with the long lower incisors. He would then raise himself slightly 
on his hind legs and hold the fragment between his fore paws while 
eating, for he usually ate a certain quantity before putting any into the 
pouches. If small pieces were given him he took tliem prom^itly and 
passed them quickly into the pouches. Some pieces were thus disposed 
of at once; others were first trimmed by biting off projecting angles. 
As a rule one pouch was filled at a time, though not always, and the 
hand of the same side was used to push the food in. The usual course 
is as follows : A piece of potato, root, or other food is seized between the 
incisor teeth, and is immediately transferred to the fore paws, which are 
held in a horizontal position, the tips of the claws curving toward one 
another. If the food requires reduction in size, the trimming is done 
while held in this position. The piece is then passed rapidly across the 
side of the face with a sort of wiping motion which forces it into the 
open mouth of the pouch. Sometimes a single rapid stroke with one 
hand is sufficient; at other times both hands are used, particularly if the 
piece is large. In such cases the long claws of one hand are used to 
draw down the lower side of the opening, wliile the food is poked in with 
the other. It is obviously impossible for the animal to i)ass food from 
the mouth to the pouches without the aid of its fore claws. 

The most remarkable thing connected, with the use of the pouches is 
the way they are emptied. The fore feet are brought back simulta- 
neously along the sides of the head until they reach a point opposite the 
hinder end of the pouches; they are then pressed firmly against the 
head and carried rapidly forward. In this way the contents of the 
pouches are promptly dumped in front of the animal. Sometimes several 
strokes are necessary. I am not prepared to say that the animal can 
not empty the pouches by means of the delicate investing muscles, but 
I have never seen them emptied in any other way than that here 


The food consists chiefly of roots, tubers, and other rather hard veg- 
etable substances, though grass and the. succulent parts of plants are 
sometimes eaten. In agricultural districts the animals are highly inju- 
rious, destroying potatoes and other tubers in large quantities, and 
gnawing off" the roots of fruit trees. In fields of grain and fodder they 
sometimes do considerable damage by the aggregate area covered by 
the little mounds of earth thrown up from the tunnels. 


In- most species of the Geomyidw two color phases occur, a plumbeous 
or dusky phase and a chestnut-brown or yellowish-brown phase. The 
latter varies greatly in the different species — from pale straw color or 


buffy ochraceous in Tliomoinys perpallidus of the Colorado and Mohave 
deserts, to dark liver-brown in Geomys bursarius of the Ui)per Missis- 
sippi Valley. Taking the group as a whole, the brown phase is by far 
the commonest and may be regarded as normal ; but in certain vSpecies 
in nearly all the genera the plumbeous i)hase prevails, as in Thomomys 
Orizaba' J Platygcomys fumosus, and Zygogeomys tricJiopus — all from south- 
ern Mexico. The plumbeous pelage is commonly more or less metallic 
antl sometimes even iridescent. It is rare in the United States species, 
though conmion in Thomomys neradensis from central Nevada and 
Geomys breviceps from Louisiana. It has not yet been observed in Gra- 
iogeomys castaiwps or Geomys lutescens, and the red pelage has not been 
observed in Zygogeomys tricliopus. So far as known, only a single color 
phase occurs in the genera Heferogeomys and Orthogeomys, both of 
which are dark seal brown in fresh pelage and a dull faded brown in 
worn iDclage. 

Seasonal differences in coloration. — Some of the species vary but 
little with season, as Geomys bursarius from the Upper Mississippi Val- 
ley; still even this animal is considerably darker in winter than in 
summer. Others present two well-marked color phases, according to 
season. In the latter category are Geomys lutescens, breviceps, and to a 
less degree personatus also. In lutescens the summer pelage differs 
from the winter in the absence of the dark dorsal band which is usually 
present from October to April, or May, and sometimes even as late as 
June. Apparently the absence of this stripe in summer specimens is 
sometimes due to wear, the dark tips of the hairs when worn leaving 
the pale subapical zone exposed. This can not always be the case, 
however, since one specimen from Chadron, Nebraska, collected April 
30, has the dorsal stripe plumbeous throughout with but a faint trace 
of the pale.subapical zone. 

In typical Geomys breviceps, and also in specimens from the western 
limit of the range of the species wliere it seems to be shading toward 
lutescens and texensis, the same thing occurs, though the renewal of tlie 
pelage takes place at a somewhat different date. This is very apparent 
in si)ecimens from Gainesville, in the valley of the Ked River in north- 
eastern Texas. A specimen taken August 10 has a broad dark dorsal 
ban(i, while two specimens taken March 27 and March 29 show no 
trace of this band except on the head, the back being a uniform red- 
dish brown more or less mixed with dusky. 


Sexual variation is marked.throughout the genus and in some species 
is extraordinary. It may "be conveniently discussed under two heads, 
(1) difference in size: (2) ditference in cranial characters. 

(1) Difference in size. — ^Tlie females are always considerably smaller 
than the males; the discrepancy is greater in some species than in 
others. Reference to tbe tables of measurements shows that the dif- 

JAN.. 1895.1 VARIATIONS. 21 

fereuce in total length often amounts to 25 or 30 mm.; in length of tail 
to 12 or 15 mm. ; and in hind foot 3 or 5 mm. Tlie difference in the size 
of the skull is equally marked, and is well shown in the tables of 
cranial measurements. 

(2) Difference in cranial characters.* — Independent of the conspicu- 
ous differences in size between male and female skulls of the same 
species from the same locality, other and more important differences 
exist which not infrequently prove troublesome in identifying speci- 
mens, particularly if skulls of both sexes are not at hand for compari- 
son. The female as a rule has the brain case broader and flatter, the 
zygomata narrower and less angular, the jugal narrower anteriorly, 
the rostrum and nasals shorter, and the skull as a wliole smoother. In 
other words, the cranium of the female is much less specialized than 
that of the male and often jioints suggestively to the stock from which 
the species was derived. It thus happens in the case of series of 
species in which the successive forms in the development of a particu- 
lar type are still extant (as in the texensis-hursarius series) that the 
female resembles the male of the species next below in the line of 
descent more than the male of her own species. 

In several forms in wiiich the males have well developed sagittal 
crests, the females have a sagittal area bounded by distant temporal 
impressions; and in species in which the males have iirominent tem- 
poral ribs, the females commonly have more widely separated temporal 
impressions which rise as ridges from the outer side but not from the 
inner side, the interspace being more or less thickened. 


The family Geomyida' i^resents the usual range of individual varia- 
tion, both in size and in cranial characters. While the male and female 
skulls of a species agree very well among themselves, showing strong 
average characters, there are in every large series one or two skulls 
which depart from the type in one or more particulars. These depart- 
ures are most common in the form aud manner of ending of the nasals 
and ascending branches of the premaxilla. In all such cases sexnal 
differences should be carefully eliminated before assuming that the 
departure is individual. 

Individual variation is always more marked in the secondary or acces- 
sory cranial structures than in the more important and less variable 
elements. Thus the peripheral processes aud expansions for the attach- 
ment of muscles are always more variable than other parts of the skull. 
The degree of lateral production of the squamosal, and of the angular 
process of the mandible in Platygeomys gymnurus, and the variations in 

' The sexual organs are so arranged in the Gcomuidw as to be difficult of determi- 
nation in the flesh, except during the rutting season ; hence the sex marks on labels 
may be safely ignored if they coullict with the cranial characters. 


detail of the occipital basiu, are illustrations of this kind. Still, in 
studying" large series of skulls of a single species, one is inucli more 
deeply impressed by the strong tendency toward the development in each 
bone of a particular type of form than by the departures therefrom. 

The animals continue to grow for several years, so that the majority 
of breeding individuals are still far from the full size of their species. 
This is very apparent in the skulls, which not only continue to increase 
in actual size but also, in many species, in the ratio of zygomatic breadth 
to length, and in the development of ridges and processes for muscular 


A superficial examination of the skulls of the various species of 
Geomyidw is sufficient to show the existence of several widely different 
types. Heretofore tlie common practice has been to divide the family 
into two genera, Thomomys and Geomys, according to the absence or 
presence of distinct grooves in the upper incisors, and to subdivide the 
genus Geomys into two series, unisulcate and bisulcate. The number 
of grooves was believed to be correlated with certain cranial characters, 
the members of the unisulcate series having widely spreading zygomatic 
arches, the outer angles of which were broadly exjianded, while the 
bisulcate series had narrower arches and lacked the expansion; but no 
attempt was made to separate them, even subgenerically. The recent 
discovery of a large number of new forms in Mexico and Central Amer- 
ica, comprising several highly diversified types, renders this classifica- 
tion inadequate. After subtracting the strongly marked genus Thom- 
ojiiys, which differs from all the others in numerous important charac- 
ters heretofore overlooked, a heterogeneous assemblage remains, com- 
prising the animals commonly lumped under the generic name Geomys, 
and also the new forms here first described. Of these, the bisulcate 
series may be divided into two very distinct and two minor types, while 
the unisulcate series contains at least six well-marked subdivisions. 

In attempting a logical classification of the group, one is met at the 
outset by the difficulty that some of the specialized or peripheral types 
are more or less closely connected with the trunk line by existing inter- 
mediate forms, making it exceedingly difficult to draw hard and fast 
lines without unnecessary subdivision. The genus Geomys as here 
restricted is such a case. It comprises two quite distinct branches, 
Geomys tuza and G. hursarius, which are connected with one another 
and with the trunk line, or something very near it, by a series of gen- 
eralized species, the texensis-hreviceps series. In cases of this kind two 
courses are open, either to separate the extreme peripheral forms from 
the less specialized species leading up to them, or to unite the entire 
branch under a single getuis. The latter course has been followed in 
the present instance. But each case must be decided on its merits. 
One that has been treated differently is the large limb whose ends, 
as now" known, are represented by two of Mr. Thomas's species, hulleri 

JAN, 1895.] KEY TO GENERA. 23 

and merriaml; tlie former is not far removetl from the trauk line of tbe 
group; tbe latter is one of the terminal branches. Bat the two forms 
differ in cranial and dental characters of great weight, and are further- 
more separated by an gap which is not bridged at any point 
by any of the species yet discovered. For these reasons they are treated 
as independent genera. Still another reason for this course, if another 
were needed, is the circumstance that the branch ending in merriami is 
only one of four- equally specialized terminal boughs, all apparently 
springing from and bearing the same relation to the single limb or main 
stem whose base is marked by b idler i. 

In dividing the family into genera the aim has been to select as types 
the most specialized j)eripheral forms and to assemble around them the 
less specialized species. A study of the enamel pattern of the molari- 
form teeth shows that the Geomijidcc maybe divided primarily into five 
groups, several of which are of supergeneric value, and a study of the 
fundamental cranial characters leads to the recognition of nine genera. 
By means of the following brief key, any of the species now known may 
be easily referred to its proper genus without cutting the skull: 


posterior enamel plate present on first and second upper molars. 

Upper incisor bisulcate Geomys. 

Upper iucisor uuisulcate 

Frontal strongly constricted (biconcave) between orbits Pappogeomys. 

Fiontal not constricted between orbits; very broad *Orthogeomys. 

Posterior enamel jtlate absent In first and second upper molars. 

Breadth of cranium across squamosals much less than zygomatic 
breadth ; lambdoid crest not sinuous (simply convex pos- 
teriorly) ; angle of mandible short • Cratogeomys. 

Breadth of cranium across S([uamosals greater than zygomatic 
breadth; lambdoid crest strongly sinuous; angle of man- 
dible very long Plutygeomys. 


Posterior enamel plate of upper premolar restricted to inner side. 
Posterior enamel plate present and complete on first and second upper 
Frontal not constricted between orbits; very broad; pterygoids 

long * Orthogeomys. 

Frontal strongly constricted between orbits ; pterygoids short. 
Postorbital process absent ; palatopterygoids long and slen- 
der (pterygoid part narrow) Heterogeomys. 

Postorbital process strongly marked ; palatopterygoids short 

and broad (pterygoid part very broad) Macrogeomys. 

* Orthogeomys presents an exceptional condition of the enamel pattern of the upper 
premolar. The posterior enamel plate of this tooth is evidently disappearing; it is 
present on the inner side in O. latifrons, hut is altogether absent or reduced to a 
very narrow strip in O. grandis and acalops. 



Posterior enamel plate of upper premolar complete. 

Posterior enamel plate i^rescnt on inner {liniinal) sich- onhj of first and 
second upper molars. 
Zygomatic arch couiplete without jugal (jugal inferior); incisors 

bisulcate Zygogeomys. 

Posterior enamel j^l'ite present and complete on first, second, and third 
upper molars. 
Incisors not grooved, or with a single fine sulcus on inner side. . Tliomomys. 


The accompauymg- pliylogeiietic tree is iutended to represent the 
author's conception of the interrelations of the nine living genera of 

\ HlacrogeorTLys 

Phylogenetic tree of tho GeoiiiyidiT>. 

the Geomyidcc now known. It is introduced with a full knowledge of 
the modern tendency to disregard and even belittle such attempts; but 
I am aware of no way in whicli tlie results of painstaking research 
respecting the afitinities of organisms may be expressed so graphically. 
Apparently there were four forks to the early Paleo-Geomine phylum: 
one running into Tliomomys, another producing the bisulcate series of 
Geomys, beginning with texensis or arenarius and ending in bursarius; 
the third developing the anomalous bisulcate Zygofjeomys; the fourth, 
a strictly unisulcate series, of which hulleri and albinasus are the least 
specialized forms now known, splitting into four very distinct branches, 
each of which now forms a well-niarked genus. In the case of the 


branch leading np to Geomys biirsarius the series of living forms is 
practically complete; in the case of the other branches the connecting 
links are unknown. It is evident that both Pappogeomys bulleri and 
Geomys texensis branched off from i^oints not very remote from the 
l^lace where Thomomys left the trunk line, and that they have under- 
gone relatively little modification since. 

The evolution of some types takes place in a very direct way, appar- 
ent?ly by uninterrupted progress in a definite direction, and the species 
comprising such a series, as texensis, breviceps, luteseens, and bursariiis, 
may be looked upon as stages in the evolution of the type. The origin 
of other types is more circuitous and less easily understood. For- 
tuitous variations lead to the appearance of numerous side branches, 
most of which abort before developing any very pronounced individ- 
uality. Others are moi-e fortunate. Chancing to fit some phase of the 
environment previously unutilized, they go on until a maximum of 
departure compatible with the balance of the organism as a whole is 
attained. There are several of these highly specialized departures 
from the main stem in the GeomyidWj such as Cratogeomys, Platygeomys , 
Macrogeomys, and Zygogeomys. 


Genus Gkomys Rafiuesque. 

Name of species. Type locality. 

Geomys tuza (Ord) Augusta, Georgia. 

tiiza floridanns (Aud. and Bach.) St. Augustine, Florida. 

tuza mohilensis'Siihs]). nov Mobile Bay, Alabama. 

hursariits (Shaw) Minnesota? 

lutescen sMevii-din Western Nebraska. 

hreviceps Baird Mer Rouge, Louisiana. 

hrevicepssagittalis subsp. nov Galveston Bay, Texas. 

breviceps attwaieri siibsp. nov Rockport, Aransas County, Texas. 

teidensis sp. nov Mason, Texas. 

arenarius sp. nov El Paso, Texas. 

personatiis True Padre Island, Texas. 

personatus fallax suhs]). nov Corpus Christi, Texas. 

Genus Pappogeomys nob. 

Pappogcomys huJIeri (Thomas) Talpa, Mascota, .lalisco, Mexico. 

alhiiiasns sji. uov Guadalajara, Jalisco, Mexico. 

Genus Cratogeomys nob. 

Cratogeomys merriami (Thomas) Valley of Mexico. 

perotcnsis &i>. nov Cofre de Perote, Mexico. 

estor sp. nov Las Vigas, Vera Cruz, Mexico. 

peregrinus sp. nov Mount Iztaccihuatl, Mexico. 

oreocetes sp. nov Mount Popocatapetl, Mexico. 

castanops (Baird) Las Animas, Colorado. 

castavops goldmaui subsp. nov. . .Canitas, Zacatecas, Mexico. 
fulvescens sp. uov Chalchiconmla, Puebla, Mexico. 


Genus Platygkomys nob. 

Platijgeomijs gymnurus Merriam , Zapotlan, Jalisco, Mexico. 

fjllorhinus sp. nov Tula, Hidalgo, Mexico. 

planiceps sp. nov Northern slope Volcau Toluca, Mexico. 

fumosHs Merriam Colima City, Colima, Mexico. 

Genus Ohthogeomys nob. 

Orthogeomys scaJops (Thomas) Teliuantepec, Mexico. 

grandis (Thomas) Duefiaa, Guatemala. 

latifrons sp. nov Guatemala. 

nelsoni sp. nov Mt. Zempoaltepec, Oaxaca, Mexico. 

Genus Hkterogeomy'S nob. 

Heterogeomys hispidus (LeConte) Near Jalapa, Vera Cruz, Mexico. 

torridus sp. nov Chichicaxtle, Vera Cruz, Mexico. 

Genus Macrogeomys nob. 

Macrogeomys heterodus (Peters) Costa Rica. 

dolichocephalns sp. nov San Jose, Costa Rica. 

costaricensis sp. nov Pacuare, Costa Rica. 

chcrriei (Allen) Santa Clara, Costa Rica. 

Genus Zy^gogeomys nob. 

Zygogeomys trichoptis sp. nov Nahuatzin, Michoacan, Mexico. 


The area inhabited by the family Geomyidw stretches from the dry 
interior of British Columbia and the Plains of the Saskatchewan south- 
ward to Costa Rica. In an east and west direction the grouj) covers 
the continent from ocean to ocean, except that it is absent from the 
region north of the Savannah River and east of the Mississippi Valley, 
as shown by the accompanying maps (maps 1, 13, and 3). The group is 
clearly of Sonoran origin and reaches its highest development on the 
sonthern r>art of the table-land of Mexico. The great majority of the 
species inhabit the upi)er and lower Sonoran zones, though a few 
specially modified forms range upward on favorable mountain sides 
through the Transition and even into the lower edge of the Boreal zone. 
On the other hand, two species inhabit the tropical belt of Mexico. 

Distribution by (jcnera. — The present distribution of the genera coin- 
cides very nicely with their systematic relations. 

The genus Thomomys (ma]) 1, A) has by far the most extended range 
of any single genus, inhabitating suitable localities from the valley of 
Mexico and Mount Orizaba northward to British Columbia and the 
North Saskatchewan river, and from the Pacific coast eastward to the 
Great Plains. 

The genus Geomys (map 1, B and B' ) inhabits a broad belt across the 
middle part of the United States, from the Red River Valley in north- 
western Minnesota and northeastern North Dakota southward to the 

JAN., 1895.] DISTRIBUTION. 27 

Mexicau boundary along- the liio Grande; and also the southern half 
of Alabama and Georgia, and the northern half of Florida. The genus 
does not occur west of eastern Wyoming, east-central Colorado, and 
the Rio Grande Yalley in New Mexico. (See also map 4.) 

The genus Gratogeomys (map 2) inhabits the Gre^it Plains of the United 
States from the Arkansas River in eastern Colorado southward, and 
the eastern table-land region of Mexico to its extreme southern edge in 
the States of Mexico and Puebla. 

The genus Pappoyeomy.s (map .'i') is known only from the State of 
Jalisco in Mexico. 

The genus Platyf/eomys (map 3^) inhabits a rather narrow belt along 
the southern border of the Mexican table-land in the States of Jalisco, 
Colima, Michoacan, Mexico, and Hidalgo. 

The genus Orthogeomy.s (map 3'') inhabits elevated parts of the States 
of Oaxaca and Chiapas, in extreme southern Mexico and adjacent parts 
of Guatemala. 

The genus Heterogeomys (map 3^) inhabits the tropical plains of Vera 
Cruz, below the edge of the table-land, and extends thence southerly to 
Coban in Guatemala, probably following the low coastal plain of 
Tabasco to the Rio Usumacinta and thence up tlie valleys of the San 
Pedro and its tributaries to the interior of Guatemala.* 

The genus Macrogeomys (map 3'') inhabits the highlands and moun- 
tains of Costa Rica and is not known elsewhere. 

The genus Zygogeomys (map 3 ') inhabits the Sierra Madre of the State 
of Michoacan on the southern ijart of the table-land of Mexico. 


Omitting the genus Thomomys, the number of species recognized by 
Baird in 1857 was 7, as follows : 0. hursarim, hrevicepSy pinctis [ = tuza], 
clarlcil, casfmiops, hispidus, and mcxicanus. The number recognized by 
Cones twenty years later, in 1877, was 5, as follows : G. bursarius, tuza, 
castaiiops, hispidus, and mexicanus. Cones degraded U of Baird's spe- 
cies to synonomy, uniting hreviceps with bursarius, and clarkii with 
castanops. The same fate overtook G. heterodus of Peters, described 
111 the interval between Baird and Cones ; it was made a synonym of 

The number of species and subspecies recognized in the present 
paper is 37, of which 21 are described as new. The remaining 16 are 
accounted for as follows : Four out of the 5 admitted by Coues are 
retained, namely, bursarius, tuza, castanops, and hispidus, but the tilth, 
mexicanus, is rejected as preoccupied by an unidentifiable species (see 

' While this paper is passing through the press, a specimen of Heterogeomi/s has 
been received from Mr. Nelson, collected by him at Reyes, about 50 miles north of 
the city of Oaxaca, in the State of the same name, and 33 miles south of the bound- 
ary of Vera Cruz and Puebla. 


postca, p. 200). Baird's hrevleeps and Peters's heterodus are rein- 
stated as valid species, and jioridanus of Audubon and Bacliman is 
admitted as a subspecies of tuza. Tlie remaining 9 have been described 
since the publication of Coues's Monograph — in fact, during* the past 
five years — and no less than G of them are from Mexico and Guate- 
malii. These species are: personatns oiTv\m; biiUeri* grandis, scalops, 
and merriami of Thomas; lutescenSy fumosus, and gymnurus of Mer- 
riam, and dierrici of Allen. Of the 21 new forms here described, 6 
are from the southern United States (1 from Alabama and 5 from 
Texas), 12 from southern Mexico, 2 from Costa Eica, and 1 from Guate- 
mala. Of the total number here recognized (37), 10 are restricted to 
the United States; 2 (probably 3t) are common to the Unitetl States 
and northern JMexico; 17 are restricted to the southern half of Mexico; 
2 are common to southeastern JVIexico and adjacent parts of Guate- 
mala, and o are known froui Guatemala and Costa Eica only. Thus 
no less than 24 species, representing, as will be shown later, 7 distinct 
groups or genera, are absolutely contincd to southern Mexico and north- 
ern Central America. The extraordinary and unexpected richness of 
this part of tropical America iu members of the group, | and the even 
more remarkable div^ersity of structure presented by the various types, 
are of the utmost interest in view of the time and place of origin of 
the family to which they belong. 


The Pocket Gophers of the United States fall naturally into two prin- 
cipal subdivisions, (1) those having the upi)er incisors deeply marked 
by a median longitudinal furrow {unisulcatc series), and (2) those having 
the upper incisors double grooved, a narrow sulcus on the inner margin 
of the tooth and a larger and deeper one near the middle (bisulcate 
series). The unisulcate series is represented by a single species, casta- 
nops of Baird, which inhabits the western plains from middle Colorado 
southward into Mexico. The members of the bisulcate series iuhabit- 

* G. hulhri was descriljed ahiiost siuuiltaneonsly by Mr. Tlionias and myself, but 
Mr. Thomas's descriptiou was issued tirst aud liis iiainc btilhrl Las i>riority over my 
name iichoni. 

I These are Geomijs arenarius, which is common on both sides of the Rio Grande 
at El Paso, Texas, and Juarez, Mexico, aud Crato(jeomijs castunops, which inhabits 
extensive areas in western Texas and Chihuahua. A third species, Geomys pemo- 
natus, inhabits the lower Rio Grande region iu Texas and iu all probability occurs 
on the Mexican side also (in the state of Tamaulipas). 

iWheu it is remembered that only about half a dozen specimens, all told, have 
been examined from Costa Rica and Guatemala, as compared with 200 front Mexico, 
it must be evident that the possibilities of Central America have been by no nutans 
exhausted. Furthermore, no specimens have been seen from Yucatan, though the 
lamily is represented there by at least one species. (Biologia Ccntrali-Americana, 
Mammalia, 1880, p. IGO.) 



iiig the United States are 12 in uiimber. These, with tlieir type locali- 
tie;', are as follows: 

Gcomi/s liiza (Ord) Augusta, Georgia. 

tuzafloridanus Bach St. Augustine, Florida. 

tuza mohilensis subsp. iiov Mobile Bay, Alabama. 

bursarius (Shaw) Miuuesota?. 

lutescens Merriam Birdwood Creek, western Nel)ra8ka. 

hreviceps Baird Mer Rouge, Louisiana. 

hreviceps sagittalis subsp. nov Galveston Bay, Texas.^ 

hreviceps atlwateri subsp. nov Roekport, Aransas County, Texas. 

/exojsis sp. nov Mason, Texas. 

rt) enarius sp. nov El Paso, Texas. 

pemonatus True Padre Island, Texas. 

personatus faUaX. subsp. nov Corpus Christi, Texas. 

Geomijs bursarius is thecoiiiinoii Pocket G-opherof the northern Mis- 
sissippi Valley, from eastern North Dakota and western Minnesota 
south to southeastern Missouri. It is a dark liver-colored animal with 
pure white forefeet, in sharp contrast to the color of the surrounding 
])arts, and has the longest claws of any of the bisulcate species. 

Ocomys lutescens is a pallid form of the bursarius type, inhabiting the 
arid sand hills of western Nebraska and extreme eastern Wyoming, 
and ranging thence southerly into northwestern Texas. 

Geomys brerieeps inhabits the alluvial lands of Louisiana, Arkansas, 
and eastern Texas, the typical form coming from Prairie Mer Rouge, 
in Morehouse Parish. It extends thence northwesterly up the valley 
of the Arkansas Kiver nearly to the Kansas border. It is a rather small 
dark species. On the south, along the coast region of Texas, it splits 
up into the two following subspecies : 

Geomys breviceps sagittalis inhabits the gulf coast of Texas about 
Galveston Bay. It is smaller than true breviceps. 

Geomys breviceps attwateri inhabits the coastal plain and islands of 
Texas, from Nueces Bay northward to Matagorda Bay, and ranges into 
the interior nearly to San Antonio. . It is considerably larger than 
typical breviceps. 

Geomys texeiisis in its typical form inhabits central Texas. On the 
north and northwest it probably passes into lutescens, while on the east 
it may intergrade with breviceps. It is much smaller than bursarius or 
hitescens and has a pure white belly. Its upper parts are reddish- 
brown, paler than bnrsariuSj but darker and brighter than lutescens. 

Geomys arenarius inhabits a very restricted area in the upper Rio 
Grande Valley in extreme northern Chihuahua, western Texas, and 
southern New Mexico. So far as known it is completely isolated, not 
coming in contact with any other bisulcate species. It is of medium 
size, has a relatively long tail, and the upper parts are drab. 

Geomys personatus mhaibitaVadre Island and the adjacent coavSt of 
Texas from Santa Rosa southward, extending inland as far as Carrizo, 
on the Rio Grande; its range, together with that of its subspecies /rtZ/fw, 
thus coincides with the northern arm of the arid tropical belt along the 


Gnlf coast. lu external appearance persoiiatus muck resembles G. 
lutescem of the Great Plains, from which it may be distinguished at 
once by its larger size, larger and more naked tail, and by important 
cranial characters. 

Geomys persofiatus faJlax inhabits a small area on the Gulf coast of 
Texas, immediately south of Xueces Bay. It is smaller and darker than 
tvne personatus. 

Geomys tuza, a rather large cinnamon-brown species, inhabits the pine 
barrens of eastern Georgia, where it is locally known as tlie 'Sala- 
mander.' The same name is applied to the following subspecies: 

Geomys tuza Jioridamis is a Florida form of tnza^ as its name indi- 
cates, and does not differ materially in external appearance. 

Geomys tuza mohllensis inhabits southern Alabama and northwestern 
Florida and is a strongly marked form. It is very much darker than 
tuza. ( For distribution of United States species see map 4). 


At my request Mr. Nelson has prepared the following note, embody- 
ing his personal knowledge of the geographical and vertical distribu- 
tion of the species obtained by him in Mexico, exclusive of the genus 
Thorn omys : 

'•One of the most remarkable and interesting features connected with 
the Mexican Pocket Gophers is the small area within which most of the 
laiown species occur. This area is a belt about 400 miles in length by 
()0 in breadth, stretching from the Pacific coast to the Gulf of Mexico, 
between the nineteenth and twentieth parallels of north latitude. It 
contains tlie thirteen highest peaks of Mexico,* all of which attain an 
altitude of lL*,Ono feet or upward. The most notable of these are Iztac- 
cihuatl (17,000 feet), Popocatapetl (17,523 feet), and Orizaba (18,314 

*Tlie only peak in Mexico attaining an altitnde exceeding 12,000 feet, in addition 
to tliose here cnnmerated, all of which lie in the Geomys belt, is Mount Zenipoal tepee, 
in the State of Oaxaca. This peak is said to reach 12,000 feet, and is inhabited bj' a 
new species of gopher here named Orthogeomys nelsoni. 

IThe complete list with approximate altitudes, beginning at the westernmost, is as 
follows : Yeei. 

Sierra Nevada de Colinia 14, 000, State of .Jalisco. 

Volcano de Colima 12,000, Do. 

Pico de Tancitaro 12, 653, State of Michoacan 

Pico de Patamban 12, 200, Do. 

Volcano de Toluca 15, 000, State of Mexico. 

Cerro de Ajusco 12, 000, Do. 

Popocatapetl 17, 523, State of Puebla. 

Iztaccihuatl 17, 000, Do. 

Cerro de Telapon 13, 575, Do. 

Cerro de Maliuche 13, 462, State of Tlaxcala. 

Orizaba 18, 314, State of Puebla. 

Sierra Negra , 15, 000, Do. 

Cofre do Perote 14, 000, State of Vera Cruz. 

JAN. 1885. 


"The maiu cliaiu of the Cordillera or Sierra Madre extends along this 
line and forms here the southern limit of the plateau or table-land region. 
The mountains throughout this district are of volcanic origin. They 
inclose numerous high valleys, such as that of Toluca (8,000 feet) and 
the valley of Mexico (7,400 feet). The main body of the range takes 
the form of high rouuded ridges between 7,000 and 9,000 feet in altitude. 
On the north the ridges slope down to the adjacent tablelands; on the 
south a longer slope carries their bases into the low hot valleys of the 
streams that lead out to the sea. The average elevation of the belt 
under discussion is far greater than that of any other equal area in 
Mexico or Central America; this belt also contains the only peaks of 
the region that are permanently capped with snow, 

"The characteristic trees of all these mountains are pines, firs, and 
alders. In descending toward the hot coast country, below 7,000 feet, 
oaks come in, and as the descent is continued they in turn give way 
before the subtropical and tropical species. Although most of the area 
within the limits given is high and cool, yet at each end a sharp 
descent leads to the low, hot coast country. 

"Gophers occur throughout this area, from the hot coast districts up 
to the scattered vegetation about timber line. Geomys fumosus, the 
extreme westernmost species, burrows in the damp clayey soil among 
the cocoanut palms about the city of Colima, at an altitude of from 
1,000 to 2,500 feet. Geomys M.spidus, the easternmost representative of 
the groui), inhabits the coffee and sugar-cane fields of V^era Cruz. In 
the intervening district the other species range from 4,000 feet up to 
timber line. Although several reach as high as 12,500 or even 13,000 
feet, the great majority of individuals of all species occur below 9,000 
feet, and a vertical section of the country from 4,000 to 9,000 feet would 
include all of the species and nearly all of the individuals of the 
interior forms. By far the greatest development of the group is 
reached between the altitudes of 0,000 and 8,500 feet. This area is 
along the lower border of the pine and oak forest and reaches out along 
the adjacent treeless plains for a short distance. Considered faunally, 
this area is Upper Sonoran and Transition. The northern base of this 
part of the Cordillera forms the southern limit of many species of 
birds and mammals belonging to the great interior deserts of the 
United States and the x^lateau of Mexico, while their southern base 
and adjacent slopes form the northern limit of various tropical species. 

"It was observed also that whenever the route led to the north or 
south of this belt the pocket gophers became rapidly less numerous, 
and ceased entirely except in a few i)laces, 

"By far the greater number of species now known from Mexico are 
absolutely restricted to limited areas within this district, while others 
push out only a little beyond. 

" The animals, as a group, are generally found in rather loose soil and 
avoid stony areas. In some cases, as with G. funiostis, the soil may be 


a tough clay, but this is exceptional. Wherever fouud in cultivated 
districts they invade fields, and frequently commit serious damage to 
crops of both grains and tubers. It is a common practice for the land- 
owners to pay a fixed bounty to their field hands for them. The owner 
of a hacienda near Atlisco, Puebla, told me he had thus iiaid for sev- 
enty dozen on his hacienda in a single year, at the rate of (3 cents a 

The most interesting and unexpected result of Mr. Nelson's explora- 
tions is the knowledge that the family Geomyidw attains its highest 
development in a belt about 400 miles in length by GO in breadth 
which crosses Mexico from west to east along the southern edge of 
the tableland. Within this belt Mr. Nelson collected 175 specimens, 
not counting this genus Thomomys. These specimens belong to six 
different genera and represent 15 species, no less than 12 of which 
were previously unknown.* 


Nothing is more difficult, in entering upon the study of a new group, 
than to determine the relative weight of characters. Structures of known 
stability in one group may be highly variable in another, so that char- 
acters that are of generic value in the one may be of only specific value 
in the other. In framing genera and higher groups therefore it is 
desirable to select deep-seated structures and those that are not easily 
affected by external influences. In the case of the skull, it is conven- 
ient to divide the characters into two categories, fundamental or pri- 
mary, and superficial or secondary. Fundamental characters are based 
on structures and relations that enter into the ground plan of the skull, 
and are of high morphologic weight; super fjciaJ characters are the result 
of special adaptations and particular muscular strains, and are of little 
value except as aftbrdiug recognition marks for species, and in some 
instances for genera also. The fundamental structures are mostly 
hidden, comprising the floor of the brain case, the craniofacial axis, and 
the turbinated bones. They are seen to best advantage in vertical longi- 
tudinal sections and in skulls from the vault of the cranium has 
been removed. On the outside of the skull the palatopterygoid plates, 
and perhaps the frontals also, may be regarded as belonging to the 
same category. The superficial structures are those that appear on the 
outer side of the cranium and are most easily modified by muscular 
strain, or are the secondary result of dental peculiarities. They com- 
prise the zygomatic arches, muzzle, nasals, occiput, and such parts of 

* Since the above note was written — in fact just as tbis paper is going to press — 
Mr. Nelson bas sent me 15 si>ecimens of large gopbers from tbe f-'tato of Oaxaca, in 
extreme southern Mexico. Ton of these, from Cerro San Felipe, are the species 
recently described by Mr. Oldiield Thomas as Geomys scalops; the remaining .5 are a 
new &\iL'.c\es, Orlhofjeomys nelsoiii. They were collected at three localities: Mount 
Zempoaltepec, Totontepec, and C'omaltepec. All of tbe specimens from the State of 
Oaxaca belong to a genus (here named Orthogeomyti) quite distinct from nny of the 
genera inhabiting Mr. Nelson's Geomys belt. 

JAN., 1895.] 



tlie outside of the vaultof the craiiiuni as are niateiially altered in form 
and extent (as tlie squamosals) without sensibly changing their relations 
on the inner side of the brain case. 


Geomys tuza (Ord) 32 

4*/2'a//o/-irf«H«s( And. and Bach.) 25 

titza mohilennis subsp. nov ... 23 

bumarhts (Sliaw) 116 

lute-scens Merriam 136 

hrexnceps Baird 195 

hreviceps Hagittalis siibsp. nov. 26 

brevieeps (iftwaferisnhs'p. nov. 53 

texensis sp. nov 31 

arenarius sii.nov 43 

personatus Trne 33 

])ersonatHS faUaxm\\)&\^. nov.. 22 

Pappogeomys bulleri (Thomas) 6 

albinasiis sp. nov 1 

Cratoyeomys merriami (Thomas) 31 

perotensis sp. nov 13 

estor sp. nov 10 

pcreyrin us sp. nov 1 

oreocetes sp. nov 1 

Cratoyeomys castanops (Baird) 


casfanops yoldmani snbsp. 



fiilvcscens sp. nov 


Platyycomyfi yymiiiirus Merriam 


tylorkhi MS sp. nov 


phin'ireps sp. nov 


f 11)11 osus Merriam 


Orthoyeomyfi scdJops (Thomas) 


iielsoui sp. nov 

latlfrons sp. nov 


Heieruyeomys hispidiis (Lc Coute) 


torridus sp. nov 


Alacroyeomys heterodus (Peters) 


dolicliocephahis sp. nov.. 


eostaricensis sp. nov 


chcrriei (Allen) 


Zyyoyeomys trichopas sp. nov 




While diversity prevails in the form of the cranium as a whole and in 
a nniltitude of minor details, all the members of the family GeomyuJm 
agree in the following important characters: The top of the skull is 
llattened, the nasals, frontals, and parietals usually forming nearly a 
straight line (though the line is decidedly convex in Gratogeomys cas- 
tanops ?ind fulvescens). The tympanic or audital bulhe are rather large, 
and the external meatus is a long tube directed forward as well as out 
ward, and opening externally immediately behind the posterior angle 
of the zygoma. There is a well-developed mastoid bulla which is wholly 
on the occipital plane, never reaching the top of the skull. The squa- 
mosals are largely developed, always overlapping the lower part of the 
parietals and hinder part of the frontals, and sending out posteriorly 
a lateral arm which enters into the occipital plane and overreaches the 
mastoid process of the mastoid bulla. They articulate broadly with 
the alisphenoid, but leave a long slit-like vacuity between the postero- 
inferior margin and the audital bulla. The hasisphenoid and presplienoid 
are higher than broad. The former develops air cells in its body; the 
latter is a thin vertical plate always j)erforate anteriorly opposite the 
7433— :^o, 8^ 3 


splieiioidal fissure, so tliat in viewiug the skull from tlie side oue sees 
completely tlirougli it below tbe orbitospheuoids. The alisplienoids 
are larger and reach, or nearLy reach, the upper surface of the cranium; 
they are inseparably ankylosed to the basisphenoid before birth. The 
orhitosphenoids are small and horizontal and are not united to the ali- 
sphenoids except in Zygogeomys and Thomomy,s. The turbinated hones, 
while presenting important differences in the several genera, agree in 
the following particulars: Anteriorly there is a Hmg\e7naxillo-turbinal, 
always attached to the premaxilla; above and i)arallel to it is a large 
fiaso-tnrhinal, always attached to the nasal; posteriorly, and attached 
to the cribriform plate and os planum are the endoturhinals (of Harri- 
son Allen), always four in number and always decreasing in size from 
above downward; the uppermost is expanded anteriorly. 

The hony palate is long and narrow, broader posteriorly than anteriorly, 
and composed chiefly of the maxilld, the body of the |>a/a/m£; being rel- 
atively small and situated far back. There is a deep pit on each side 
of the palate between the hindermost molars. Posterior to this pit the 
palatines usually bifurcate and unite, with the pterygoids to form a 
Ungulate or strap-shaped palatopterygoid plate on each side of the poste- 
rior nares. On the outside of the skull the palatines are restricted to 
the posterior eiul of the bony palate, but on the inside they reach 
forward along the crano facial axis all the way to the nasal chamber — 
a wholly unnecessary condition so far as the i)resent structure and needs 
of the animal are concerned, but a highly interesting and significant 
relic of the primitive relations.of these bones. The case is an excellent 
illustration of the persistence-of. useless parts. 

T\\Q premaxilla is large and heavy, subquadrate in section, and artic- 
ulates rather broadly with the frontal. It completely incloses the small 
incisive foi-amina except in Zygogeomys. 

The jugal is a highly variable bone (as will be seen hereafter), but 
it is always restricted to the horizontal part of the zygoma, never 
creeping upward anteriorly toward the lachrymal, or inward i)Osteriorly 
toward the glenoid fossa. 

The vomer bifurcates and sends backward two long vertical wings, 
which articulate with the sides of the presphenoid, never with its 
inferior surface. 

The zygomatic arch varies exceedingly in size and form in the differ- 
ent subgenera, but its horizontal part in transverse section is always 
distinctly triangular anteriorly, while posteriorly it is fiat or rounded. 
Posteriorly it presents two faces, inner and outer; anteriorly a third is 
added — a supero-external face. The latter rarely reaches further back- 
ward than the middle of the arch and is usually set oft" from the outer 
lace by a well-defined ridge, which passes obliquely backward and 
upward from the antero-exteriial angle to the tip of the squamosal 
arm. This ridge marks the upper limit of attachment of the zygomatic 
part of the masseter muscle. 


There is no true 2)ostorbital process of the frontal except iu Macrogeo- 
mys, but the apex of the alisphenoid and adjoiuiug anterior "border of 
the squamosal commonly unite to form a decided postorbital ridge, which 
slopes obliquely downward and backward from the i)oint where the 
frontal, alisphenoid, and squamosal meet, just behind the orbit. This 
ridge is made up of the edges of the alisphenoid and squamosal, and 
serves to sharply separate the orbit from the adjoining outer side of the 
brain case. In Macrogeomys there is a strongly developed circumscribed 
postorbital i)rocess, which, with the help of a corresponding eminence 
on the middle of the horizontal part of the zygoma, serves to sharply 
distinguish the orbital from the temporal fossa. In its component 
elements it is peculiar. Its base consists of the frontal, which bone is 
notched immediately in front of it, thus emphasizing the appai'ent size 
of the process. The summit of the process is made up of the apex of 
the alisphenoid, which hero reaches the plane of the upper part of the 
skull and is slightly overlapped posteriorly by the autero-external angle 
of the squamosal. 

T\\Q paroccipital processes stand out sideways above the condyles and 
are more or less expanded and flattened — never cylindrical or conical 
(figs. 4 and oo pp. and x)l. 15, tigs. and 7). 

The^oor of the brain case, as exposed by sawing oft' the vault of the 
cranium, affords characters of the utmost value in subdividing the 
group into genera (figs. 9, 5G, and 08^, and i)l. 17). As will be seen 
on consulting fig. 9, the tympano-periotic capsules, with the inclosed 
basioccipital and posterior part of the basisphenoid, form about half of 
the floor of the brain case. The alisphenoids (fig. 9, as) are next in 
importance, the horizontal part forming abridge across the floor of the 
skull above the pterygoid foss;e and immediately iu front of the tym- 
panic bulhe, while the ascending wings push forward on each side, 
reaching or nearly reaching the orbitosphenoids (os), and forming the 
posterior and outer boundaries (»f the large sphenoid fossa. Anteriorly 
the orbitosphenoids fill or nearly fill the front part of the floor of the 
brain case, on the plane of the orbital constriction. In front of this 
constriction, and behind the cribriform plate, the orbital or descending 
iflates of the frontal commonly meet in the median line, forming the 
floor of the olfactory fossa. In young skulls, as in fig. 9, and iu adults 
of the genera Pappogeomys (fig. 56), Orthogeomys, and Thomomys {&g. 08^), 
the frontals do not meet below, but the orbitosphenoids reach forward 
and articulate directly with the cribriform plate. 

A conspicuous and highly important pair of fossa; occupy the ante- 
rior part of the floor of the brain case on each side of the median line, 
where they are completely surrounded by the several sphenoid bones. 
They may be termed the sphenoid fossw. They are directly continuous 
and inseparably connected posteriorly with the pterygoid fossce proper, 
which latter are widely oi)en in front and are roofed over bv the trans- 


verse part of the alisplienoid only. The resulting elongated fossa as a 
whole may be named the spheno-pterygoid fossa (Hg. ^yptf). The shape 
aud extent of the sphenoid fossa varies materially in the different 
genera, as shown in pi. 17: in Geomys (tig. 3) and Heterogeomys (tig. 1) 
it is much elongated, reaching anteriorly to the descending plate of the 
frontal. In Cratogcomys (fig. 0, pi. 17, and fig. 5), and also in Fappo- 
geomys (fig. 56) and Orthogeoinys, it is cut oft" anteriorly by the orbito- 
sphenoids. In Zygogeomys (pi. 17, fig. 2) it is still further shortened by 
the posterior enlargement of the orbitosphenoids, which are broadly 
ankylosed with the alisphenoids. ^ 

The anterior end of the alisplienoid canal (fig. 9, ac) always opens into 
the outer side of the posterior x^art of the sphenoid Ibssa, and its posi- 
tion is essentially the same throughout the family (see pi. 17, and text 
figs. 9 ae, 52 aud 54 ale, 56, and 68). 

The pterygoid fossw are large and widely open (fig. VI, ptf). Poste- 
riorly they are bridged by the narrow horizontal arm of the alisphenoid 
(tig. 9, as); anteriorly they are not closed or roofed over, but are broadly 
continuous with the large and deep sphenoid fossae (fig. 9, pif), which 
open into the orbit by means of the broadly expanded lower part of 
the sphenoidal fissure. Their floor consists posteriorly of palatine and 
anteriorly of maxillary. On the inner side they are bounded by the 
pterygoid, the vertical plate of the palatine, the basisi)henoid, and the 
presphenoid. On the outer side they are bounded inferiorly by the 
external pterygoid plate of the palatine (fig. 12, epl), and superiorly 
by the descending wing of the alisphenoid. The outer wall of the j)os- 
terior part of the pterygoid fossa thus proves to be double, and the 
inner bone — ilie external pterygoid plate — belongs to the palatine and is 
overlapped by the descending wing of the alisphenoid, as shown in 
figs. 4 and 12. 

Thetsphenoidal fissure is a large and nearly vertical pyriform vacuity 
at the bottom of the orbit, separating the anterior border of the ali- 
sphenoid from the descending or orbital plate of the frontal (fig. 55"). 
It separates also, to a varying degree, tlie alisphenoid from the orbi- 
tosphenoid (fig. 9, sf). Superiorly (above the horizontal jilane of the 
orbitosphenoids) it is a narrow slit sloping oblicpiely upward and for- 
ward between the brain case proper and the olfactory fossa, and ending 
at the base of the thickened interorbital constriction of the frontal 
(which continues the line of separation between the olfactory fossa and 
cerebral chamber). This slit is permanently open except in Zygogeomys 
(in which it is closed by the orbltosphenoid), looking completely through 
the skull from side to side. Inferiorly (below the horizontal plane of 
the orbitos])lienoids) the fissure is suddenly dilated, forming a broad 
and widely open door between tlie deep lateral fossa of the floor of the 
brain case and the bottom of the orbit. The corresponding basal parts 
of t^e ^s,mv^ Qi] t/)J<? two sides of the skull are incompletely sep^vr^ted 

JAN., 1895.] 



by a i^erforate septum consisting- of the vertical plate of the presphe- 
noid, and in some cases of an ascending wing of the palatine also. The 
sphenoidal Assure is bounded by tliree bones : posteriorly by the ali- 

Cv I 01^ ^ 5)(\ sc^i 

Fig. 4.— Side view of skull of Cratoijeomys merriami from the outside. Zygomatic arch sawed off 
to show bottom of orbit. Animal not quite adult. Specimen from Amecameca, Valley of Mexico. 
(This figure should be compared with the corresponding view of Geomys bursaiius, fig. 55.) 

1 Infraorbital foramen. 

2 Posterior (orbital) opening of infraorl)ital canal. 

3 Foramen rotundum. 

4 Foramen ovale. 

5 Meatus auditorius externus. 

6 Fenestrum in anterior part of presplienoid (the line pointing to it cros.sos the upper part of 

the sphenoidal fi.ssure). 
apl Ascending wing of vertical plate of palatine. 
• as Alisphenoid (the upper line on the ascending wing; tlie lower on the descending wing), 
c Condyle of exoccipital. 
epl External pterygoid plate of palatine bone. 
/(■ Frontal. 

/( Ilamular process of pterygoid bone. 
I Lachrymal. 

in Mastoid process of mastoul bulla. 
mb Mastoid bulla. 
ms Mastoid process of squamosal. 
mx Maxilla. 

inx2 Zygomatic root of maxilla (.sawed off fo show orbit), 
n Nasal. 

off Orbital or dcsceuding plate of frontal. 
OS Orbitosphenoid. 
im Parietal. 
pinz Premaxilla. 

pp Paroccipital process of exoccipital. 
ps Presplienoid. 
pt Pterygoid. 
sn Supraoccipital. 
fq Squamosal. 

sqz Squamosal root of zygoma (sawed off). 
tb Tympanic or audital bulla. 

sphenoid; anteriorly by the frontal and maxilla; and inferiorly by the 
maxilla. The longitudinal vertical septum which forms the floor of the 
large inferior part of the sphenoidal fissure is likewise made up of three 



[NO. 8. 

bones, the orbitosplienoid, prosphenoid, and palatine — tboiigh tbe lat- 
ter is usually so reduced that it appears in tbe anteroinferior corner 
only, and in some forms can not be seen from tbe outside at all. But 
in tbe elongated skulls of Oeomys bursarius and tuza tbe lower part of 
tbe fissure is broadened antero-posteriorly, and tbe ascending wing of 

Fig. 55. — Side view of skull of Getmyn bursariua from outsitle, zygomatic arch sawed off to sliow 
bottom of orbit. Animal fully adult d- From Knoxville, Iowa. (Tliis figure is duplicated for easy 
comparison witli tbe corresponding view of Cratogeomys merrinmi, fig. 4). 

1. Infraorbital foramen. 

2. Posterior (orbital) opening of infraorbital canal. 

3. Vacuity in front of pi-esphcnoid and ascending wing of jialatine. 

4. Vacuity in prespbenoid, beliind ascending wing of palatine 

5. Optic foramen (in orbitosijbeuoid bone). 

6. Foramen rotundum and foramen ovale (wbicli liave liere coalesced). 

7. External auditory meatus. 

8. Sphenoidal fissure (upper part). 

a2}l. Ascending wing of vertical plate of palatine. 
as. Alisphenoid. 

c Condyle ot exoccipital. 
epl. External pterygoid jdate of palatine bone, 
/»'. Frontal. 
h. Hamular jarocess of pterygoid bone. 
I. Lachrymal, 
m. Mastoid process of mastoid bulla. 
mb. Mastoid bulla. 
ms. Mastoid process of squamosal. 
inx. Maxilla. 

n. Nasal. 
pa. Parietal. ' 

pmx. Preniaxilla. 
p}). Paroccipital process of exoccipital. 
j}s. Presphenoid. 
pt. Pterygoid. 
so. Supraoccipital. 
sq. Squamosal. 
th. Tympanic or auditnl bulla. 

tbe palatine is enlarged and extended, reacbing upward alongside tbe 
prespbenoid (in front of tbe usual fenestruin) to articulate broadly witb 
tbe frontal and orbitospbenoid, on or near tbe plane of tbe top of tbe 
prespbenoid (fig. .55). In front of tbe palatine (and also in front of tbe 
prespbenoid, wbicb is bere clasped between tbe ascending wings of tbe 

JAN., 1895.1 THE SKULL. 89 

palatine on the two sides of the skull) is a second feiiestruiii (fig. 55'*) 
anterior to the usual one (fig. o")^, which is in the presphenoid), and 
likewise looking completely through the skull. This latter opening is 
bounded iu front by the maxilla and behind by the i»alatine. It is sit- 
uated midway between the sphenoid fenestrum and the orbital end of 
the infraorbital canal. 

The infraorhital canal is small and does not pierce the root of the 
zygoma, but is deeply buried in the maxillary bone, passing backward 
and inward from the infraorbital foramen (fig. 4') (on the lower part of 
the side of the muzzle Just beliiud the premaxillary suture) to the deep- 
est part of the orbit (flg. 4-), its course being wholly internal to the zygo- 
matic root of the nuixillary. It curves around the inner side of the 
base of the socket of the long upper incisor, and is separated from the 
nasal chamber by only a thin lamella of bone rising from the maxillary 
floor of the nasal passa^;e and articulating above with the inferior boi'- 
der of that j^art of the os i)lannm which supports the endoturbinals. 

The foramen rotundum (fig.-4'') is always situated above the foramen 
ovale (fig. 4^), and both open into the large longitudinal alisphenoid 
canal. In rare instances they coalesce (fig. 55'^). 

The narial passage is a narrow vertical ellipse, about twice as high as 
broad (fig. 7, nj)). 

While most species of the genera under consideration develop a 
prominent sagittal crest in adult life, some do not, the temporal imj)res- 
sions remaining permanently distant, defining a well-marked sagittal 
area. The members of the latter category may be divided into two 
sets, (1) those in which the temporal impressions are actual ridges ris- 
ing above the level of the surrounding bone on both sides, as in Hetero- 
geomijs hispidus (pi. 4), Gcomys tuza (pi. 7, fig. 1), and G. arenarius 
(pi. 9, fig. 1) ; and (2) those in which the space between the temi>oral 
impressions (the sagittal area) is thickened and as high as the impres- 
sions, which thus appear as ridges only when looked at from the outer 
side, as in Geomys breviceps (pi. 9, fig. (») and Cratogeomys orcocetes and 
peregrinns (pi. 8, figs. 2 and 3). 

The lamhdoid crest is broadly and gently convex posteriorly through- 
out the group (pis. 1, 2, 5-9, etc.), except in Platygeomys, in which genus 
(pi. 3 and pi. 11, fig. 4) it is strongly sinuous — forming a deep and broad 
reentrant angle on the median "line, beyond which, on each side, it is 
first strongly convex backward and then slightly convex forward — the 
extreme mastoid ends curving backward as well as outward. The 
bones that take part iu the formation of the lambdoid crest are the 
supraoccipital, squamosals, parietals, and interiiarietal. 

There is no ossified tentorium in the Geomyidiv. 



[no. 8. 


Ill the Geomyidw there are normally thirty-three distinct bones in the 
skull, not counting" the separate parts of the tympano-periotic capsule, 
the turbinated bones of the nasal chamber (which are reckoned with 
the bones to which they are attached) or the paired bones that coalesce 
before birth. The latter are the preiuaxillje, maxillae, palatines, and 

The thirty-three bones that go to make up the skull (exclusive of the 
paired bones that are fused in the embryo) are: 

Basioccipital 1 

Exoccipital 2 

Supraoccipitai 1 

Interparietal ' : 1 

Basisplieiioid . . . .* 1 

Alisplienoid 2 

Squamosal 2 

Parietal 2 

Prespbeuoid 1 

Orbitosphenoid 2 

Frontal 1 

Ethmoid 1 

Vomer : 1 

Pterygoid ^ . 2 

Palatine 1 

Maxilla 1 

Premaxilla 1 

Lachrymal 2 

Jugal 2 

Nasal 2 

Periotic 2 

Mandible 2 


The hasioccipital in commonly truncate-wedge-shaped, with the pos- 
terior edge {basion) rather deeply notched. Its posterior corners enter 

Fig. 5. — Basiocciiiital of Gratogeomys merriami, showing diffeiTnce iu form of upper and lower sur- 
faces (ankylosert ex()ccii)itaI.s's]iown also): a, inferior surface; h, superior surface; pp, paroccipital 

very slightly into the formation of the occipital condyles. The inferior 
surface of the body of the basioccipital. is normally broader posteriorly 
than anteriorly and the decrease in from behind, forward is 
gradual (pi. 12, fig. 2, a\', but in one species, Cratogcomys casta7iops,tlie 
body of the bone is rectangular, its sides being parallel (pi, 12, fig.l, a). 
In another, Orihogeomys sealojjs, they may be nearly parallel or even 
slightly divergent anteriorly (pi, 19, fig. 2). The basioccipital varies 
in breadth according to the development of the audital bullae, by which 
its sides are always more or less excavated. Its outer borders are 
usually grooved to receive a i)rojectiou from the bulla. The superior 
surface (on floor of brain case) is always narrower than tlie inferior 
surface. The difference is very marked in some species (see fig. 5, a and 
6). The basioccipital early ankyloses with the exoccipitals,* but usually 

* The exoccipitals coiissify with the basioccipital very early in Zygogeomys and 
Geo/Hj/s proper ; somewhat later in Crdfof/eomi/s, Plati/f/eumys, and Ileteroyeomtjs. 

•IAN., 1895.] THE SKULL. 41 

remains distinct from tlie basisphenoid, with which it nnites by syn- 

The ejfoccipitah form the whole of the condyles except the extreme 
lower ends, into which the outer corners of the basioccipital enter. 
They early ankylose with the basioccipital, forming a single bone long 
before the animal becomes adult. No part of the exoccipital ever pro- 
jects downward below the plane of the condyles. The paroccipital 
processes stand out sideways and impinge upon the base of the mas- 
toid bulla immediately behind the audital bulla; they are commonly 
more or less flattened and expanded, and their distal ends often pro- 
ject backward (tig. 12,|>p). In Platygeomys they attain their maximum 
development and form the lateral parieties of a deep basin-shaped 
depression, the upper boundary of which is formed by the backward 
projecting lambdoid crest (pi. 15, fig. 7). The exoccipitals are in contact 
anteriorly with the mastoid bulla' and i^eriotic capsules, which they 
partly overlap. Viewed from behind, they form the inner boundary 
of the exposed i^art of the mastoid bulhie. Vertically they reach the 
upper edge of the foramen magnum, and their upper border forms 
nearly a straight line across the plane of the occiput. 

The supraoccipital forms a small part of the roof of the brain case 
and the greater part of the occipital plane, comprising all of the occi- 
pital element above the foramen magnum. On the top of the skull it 
reaches much farther forward in Plati/fjeomi/s than in the oth'er genera, 
(fig. 53, .yo), but is usually nearly concealed in adult life by being over- 
lapped by the parietal and squamosal. On the occipital plane its 
inferior border forms the superior boundary of the foramen magnum ; 
its outer sides curve around the basal part of the exposed mastoid 
bullae, though rarely reaching laterally as far as the free ends of the 
mastoids. Anteriorly the supraoccipital articulates with the squamo- 
sals and parietals, and with the interparietal also in those cases in 
which the latter bone has an independent existence. [As a rule the 
interparietal is not separate from the supraoccipital.] 

The interparietal, which has proved of considerable importance in 
furnishing specific characters in the Heteromyidce, is small and of little 
consequence in most species of Geomyidw, except in the single genus 
Thomomys. Even in very early life it forms an inseparable jjart of the 
supraocciptial in the castanops series of Cratogeomyf!, in Platygeomys 
gymmirus, in the hursarius series of Geomys proper, and in Pappogeomys, 
Heterogeomys, and Zygogeomy-s. It is distinct all around in early life in 
most s]>ecies of Thomomys, in the merriami series of Cratogeomys, iu the 
tuza series of Geomys proper, in Geomys texensis and hreviceps, in Platy- 
geomys tylorhinus and planlceps, but not in P. gymnurus. Fromits varia- 
bility in closely related species it is evidently of little importance for 
purposes of classification, though its value in Tliomomys is much greater 
than in any of the other genera; and it is of some value iu the restricted 
genus Geomys also. In the young it is commonly sub(piadrate or 
broadly oval and of relatively large size, but with advancing age it 



[NO. 8. 

becomes smaller and uanowly triaiii;ulai' or wedge-shaped, its outer 
borders being resorbed from pressure of the parietals, which are con- 
stantly crowding toward the mediau line. Thus in PlatygeomyH ti/Io- 
rhinus several sivulls from the same locality (Tula, Hidalgo, Mexico) 
present the following variations in the interparietal: 

O Q 



Tig. G.— Forms of interparietal. «, h, c, d. Platiigeom'is tylorhinus showing changes with age. 
e. Gcomys tuza iS art- Aiigiist.i, Ga. 
/and g G. mohilenais: ci f yg- .irt-: <J / ad. Milton, Fla. All natural size. 

A very young male (fig, 6, «, Xo, 51882) has it roughly subquadrate 
and broader than long; an immature but older female (fig. C&, No. 
51884) has it of the same shape, but narrower and longer than broad; 
a still older specimen (fig. Xo. fi, c) has it broadly triangular; while an 
adult (fig. G, r7, No. 51883, $ ) has it reduced to a small wedge-shaped 
piece squeezed in between the hinder edges of the parietals. 

In the young of Zygogeomys irichopus the interparietal is even larger 
than in Platygcomys tylorhinus, and is about twice as broad as long 
(measuring 8 mm. in breadth in Xo. 50104: juv. fig. 15, a). In shape it is 
broadly convex anteriorily and slightly (flatly) convex posteriorly. 
The progressive development of the powerful temporal muscles with 
consequent enlargement of the parietals posteriorly encroach upon its 
size and change its shape, pressing it into an equilateral triangle (as in 
No. 4718G S im., fig. 15, h). Its size now decreases rapidly, and as the 
temporal impressions meet in a well-developed sagittal crest in the 
adult skull it nearly or quite disappears from the upper surface of the 
cranium (as in No. 50100 S ad., fig. 15, c). 

The interparietal ?s more stable in form in several of the species of 
the restricted genus Geomy.s than in any of the other genera under con- 
sideration. This is due chiefly to the circumstance that in this genus 
several species have permanently distant temporal impressions — for 
nothing is so destructive to an interi)arietal as the development of a 
sagittal crest. In the species possessing a crest {hnrsarhis, Infescens, 
per son atUH, fall a.r, and mohilensis) the interparietal is normally reduced 

IAN 1895] THE SKULL. 43 

in adult life to an inconspicuous subtri angular wedge. In the species 
having a permanent sagittal area it remains of considerable size and 
its form is reasonably constant. In G. (ircnarius it is normally sub- 
quadrate, though the anterior border may become convex from rounding 
oft' of the corners, and it is always truncate behind and persists in old 
age (pi. 9, fig. I). In G. texensis it is normally elliptical or oval (broader 
than long) and convex posteriorly as well as anteriorly, projecting 
nearly as far behind as in front of the lambdoid suture (pi. 9, fig. 2). 
In G. hreviceps it is usually reduced to a highly irregular ' wormian' 
bone, raucli cut up by contortions of the sutures (])1. 9, fig. 0). In G. tuza 
it is very large, occupying nearly half of the broad sagittal area, and is 
convex in front, truncate behind (fig. i^e). Inthe closely related G. 
mohilensis it is deeply notched behind and is encroached upon and 
finally nearly obliterated by the union of the temporal ridges (fig. 6,/ 
and a). 

The hasisphenoid is invariably aukylosed with the alisphenoids and 
pterygoids, even in early life, and sooner or later usually coossifies 
with the presphenoid; it commonly, though not always, remains dis- 
tinct from the basioccipital. Its vertical height is generally greater 
than its breadth, and air cells commonly develop in its substance 
(fig. 7, bs). Its chief peculiarity is the slight development of the pitu- 
itary fossa, which ordinarily is so shallow as to escape notice. But in 
Heterogeomys it is a real depression, and in H. hispiiJus it is normally a 
pit and completely perforates the bone. In the related species, H. tor- 
ridus, it is much less conspicuous and never perforates (so far as the 
series of 26 skulls goes). 

Tlie basisphenoid articulates with the basioccipital, presphenoid, 
alisphenoids (by ankylosis), pterygoids (by ankylosis), and vertical 
plates of the palatines (by contact antero-inferiorly — see fig. 7). 

The alisjyJienoid is a very important bone, serving to bind firmly 
together the middle segment of the vault of the cranium with the pos- 
terior part of the upper jaw, and to anchor both securely to the basi- 
cranial axis. It maybe described as consisting of three parts, (1) a 
horizontal or transverse part, (2) an ascending icing, and (3) a descending 

(1) The transverse or horizontal part is little more than a narrow bar, 
inseparably connected with the middle of the outer side of the bas- 
isphenoid (figs. 9, as and 54, alh) ; it forms the floor of the brain case imme- 
diately in front of the periotic, and the roof of the posterior part of the 
pterygoid fossa, the anterior part being uncovered. In passing outward 
it bifurcates to inclose the large longitudinal alispheuoid canal, above 
which it becomes continuous with the ascending wing, and below with 
the descending wing. Posteriorly, the base of the horizontal part of 
the alisphenoid is excavated, and usually presents a cup-shaped enlarge- 
ment to receive the apex of the audital bulla. It also descends alongside 
the basioccipital to unite with the pterygoid posteriorly. 



[NO. 8. 

(2) The ascending icing of the alisphenoid differs widely iu form as 
viewed from the inside or outside of the braiu case. On the outer side 
of the skull (tig. 4, as) it is a long rectangular blade ascending 
obliquely in front of the squamosal, with the anterior border of which it 
articulates. It also overlaps the posterior i)art of the orbital face of 
the frontal, rising nearly to the upper surface of the skull, which it some- 
times reaches. The upper part is always roughened, and, with the over- 
la]>ping edge of the squamosal, forms an oblique postorbital ridge or 
prominence. Sometimes the apex pushes up to the top of the skull, 
where it is thickened and forms the major part of a distinct postorbital 
process, resting on the frontal, and overlapped posteriorly by the autero- 
exterual corner of the squamosal. This process attains its highest 
development in Macrogeomijs (see pi. 11, fig. 2, and text fig. 17^). Pos- 
teriorly the ascending wing is extensively overlapped by the squamosal, 

"F ''^ T3 'ti ^ u a h 

ffia, 7.— Longitudinal vertical mediau section of skull of Cratogeoini/i mernami, showinc 
of brain caso and nasal chamber. Vomer aud mesethmoid in place. 


1 Anterior palatine foramen. 

2 Incisive foramen. 

3 Meatus auditorius iuternns. 

4 Floccular fossa. 

5 Upiier part of sphenoidal fis.sure. 
as Alisphenoid. 

ho Basioccipital. 

bs Basiaplienoid. 

c Condyle of exoccipital. 

fr Frontal. 

h. Hamular process of i>terygoid. 

ip Interparietal. 

tne Mesethmoid plate. 

mt Maxillo-turbinal. 

mx MaxiUa. 

n Nasal. 

nt Naso-turbinal. 

op Lower border of os planum. 

pa Parietal. 

pet Petrous part of periotic capsule. 
pi Palatine. 
pmx Premaxilla. 
ps Presphenoid. 

Tympanic bulla (antero-superior part, 
which alone appears within the brain 
case) . 

Vomerine sheath of maxilla 
First endoturbinal (below and somewhat 
behind it the anterior ends of the sec- 
ond, third, and fourth endoturbinals 
may be seen). 


as appears when examined from the inner side of the brain case (fig. 7, 
as). Therefore, while the outer face is an obi iquely- vertical i>late, with 
essentially parallel sides, the inner face is elongated horizon tallj^, with 
an irregularly convex upper border — the difference being due to the fact 
that the outer side overlaps the frontal anteriorly and is overlapped b/ 

JAN., 1895.] THE SKULL. 45 

the squamosal posteriorly. The alispheuoid may be separated from 
the orbitospheuoid as in Heterogeomys and Geomys (pi. 17, tigs. 1 and 3), 
or the two bones may be in contact anteriorly as in Cratogeomys (pi. 17, 
tig-. 5, and text tig. 9), or they may be firmly and broadly ankylosed 
together as in Zygogeomys (pi. 17, tig. 2). 

(3) Tlie flesccnding wing of the ciMsphenoid, on the outer side of the 
skull, is a tlatteued plate continuous in breadth, plane, and direction 
with the ascending wing, and passing obliquely downward and back- 
ward between the posterior border of the maxilla and the antero- 
inferior edge of the squamosal (tig. 1, as, lower pointer). Ante- 
riorly it forms the outer wall of the pterygoid fossa; posteriorly it 
overlaps the external pterygoid plate of the i)alatine. It articulates 
Avith the maxilla, x^alatine, and squamosal; and is pierced by two fora- 
mina, the foramen rotundum and the foramen ovale, which, in rare cases, 
merge into one. The forame)i rotundum (tig; 1^) is.very inucli larger 
than the foramen ovale, and is situated immediately below the anterior 
end of the squamosal root of the zygoma. It opens into the anterior 
part of the large alispheuoid canal, and sometimes also directly into the 
deep sphenoid fossa of the floor of the brain case. In Geomys proper it 
is higher up than usual and consequently opens downward into the 
alis])henoid canal. The foramen ovale (fig. 4*) is a small slit-like 
opening beneath the foramen rotundum; it opens obliquely upward 
(and usually backward) into the lower part of the alispheuoid canal. 
The foramen ovale presents considerable variation in its position and 
relations, affording characters of some value in separating the genera. 
In Cratogeomys it is near the anterior- border of the lower part of the 
alispheuoid, directly beneath the foramen rotundum and far*below the 
alispheuoid canal, which it reaches posteriorly by an obliquely ujjward 
and backward course. In Platygeomys and Heterogeomys it is simi- 
larly situated, except that it is nearer the middle than the anterior bor- 
der of the descending wing of the alisphenoid, and is decidedly nearer 
the alisphenoid canal i\w([ foramen rotundum. In Heterogeomys it is 
not infrequently confluent on one side with the foramen rotundum. In 
Platygeomys it is somewhat jjosterior to the foramen rotundum and 
nearer it than in Heterogeomys. In Zygogeomys it is immediately below 
and close to the foramen rotundum and sometimes confluent with it; 
it is high up and opens directly into the alisphenoid canal. In Geomys 
proper it is high up also, and often becomes confluent with the fora- 
men rotundum (as in fig. 55''"). In the tuza series its size is unusually 

The alisphenoid as a whole articulates with the frontal, squamosal, 
maxilla, palatine, basisphenoid, pterygoid, tympanic capsule, and in 
some genera with the orbitospheuoid also. 

The squamosal is a large and highly important bone in the GeomyidK 
(figs. 4, 7, 8, and 0, sq). It overlaps to fi cousiderable extent the other 
Ijpnes of tUe padetiea of tUe br^iu CfVse, impartial' gre^^t power of resist- 



[NO. 8. 

ance to the vault of the cranium. Autero-iuferiorly it articulates with 
the alisphenoid for its entire leuj^th. Postero-inferiorly a long slit-like 
vacuity seijarates it from the audital bulla, though iu some cases it is 
in contact with parts of the bulla. Posteriorly it overspreads the 
sni)erior face of the outer part of the supraoccipital and the mastoid 
bulla and sends a lateral arm out sideways (the mastoid arm), which 
overreaches and articulates with the end of the mastoid process of the 
mastoid bulla. Superiorly it covers the posterior i)art of the frontals 
and broadly overlaps the i^arietals for their entire length — actually con- 
cealing them iu one species, Cratogeomys- merriami. The squamosal 
gives off the posterior root ot^ the zygoma, and articulates with the 
jugal. In Zij<jogconiy.s trichopHs and Macrogeomys costaricensis, owing 
to the much-reduced size of* the jugal, tliC' squamosal" arm reaches 
far forward and articulates directly with the maxilla — a most excep- 
tional condition among mammals. Below the squamosal' root of the 
zygoma is the elongated and ill-detined glenoid fossa, which is com- 
pleted posteriorly and on the inner side by the tympanic bulla. The 

Fig. 8. — Skull of very young Geuniyi bursaiius from Elk River, Minnesota. Upper .surface, showing 
frontals ankj'losed together, and interparietal inseparable from supraoccipital at birth. 

/(•, frontal; ip, interparietal; j, .jugal; n, nasal; ^^a, parietal; pmx, ascending branch of jjreniaxilla; 
sq, squamosal; zmx, maxillary root of zygoma. 

form of the postglenoid notch varies from broadly (J-s^i^PGd in Platy- 
geoniys and some others to narrowly V-shaped uiGeomys hursarius. In 
Platygeomys and Cratogeomys the glenoid fossa is i^roduced anteriorly 
a long distance in front of the squamosal root of the zygoma. 

The mastoid arm of the squamosal enters the outer part of the occip- 
ital plane above the mastoid bulla and external to the supraoccipital, 
where it forms the whole thickness of the lambdoid crest (see pi. 15, 
tigs. 3, 4, 6, and 7). In Heterogeomys it is vertically expanded, taking 
a more prominent part than usual in the occiput. The variations in 
the squamosal are described later (pp. 66-67). 

The parietals complete the roof of the brain case posteriorly (fig. 8,^a). 
They do not in-esent any unusual variations in the Geomyidw; they over- 
lap the frontal anteriorly and the supraoccipital and interparietal poste- 
liorly, and are overlapx)ed for their full length inferiorly by the squa- 
mosals, which in Cratogeomys merriami gradually overspreadandconceal 
them. The parietals are always separate iu early life, but usually coa- 

JAN., 1895. 



lesce in the adult. The temporal impressions may remain permanently 
distant, defining- a sagittal area, or they may unite in a prominent 
sagittal crest. 

The pre.sphenoid is a thin vertical plate of bone bridging the gap 
between the basisphenoid and mesethmoid cartilage and supporting, 
from its superior surface, the horizontally flattened orbitosphenoids 
(figs. 4, 7, audi), 29S*), It is perforated anteriorly by a rather large 
opening, which, being opposite the sphenoidal fissure, enables one to see 
completely through the skull at this point (figs. 46, H)\ and 55^). A 
second fenestrum often exists behind the first, and in Orthof/eoiiiys one 
or two small perforations usually occur in front of it. 8ui)eri()rly the 
prespheuoid supports the orbitosphenoids (tig. 9, oi), with which it is 

t\r Kna 

^ ^^ 

Fin. 9.— Young skull of Cratogeomys merriaiai 
removed to sliow floor of brain case. 

ac Anterior opeiiing of alisiilienoid canal. 

as Alisphenoid bone. 

bo Basioccijjital. 

bs Basisphenoid. 

Condyle of exoccipltal. 

cr Cribriform plate of etlimoid. 

em External auditory meatus. 

ex Exoccipital. 

ff Floccular fossa. 

fr Frontal. 

fro Descending or orbital plate of frontal (tlie 
animal is so young tliat the plates of the 
, two sides have not yet united below). 

' Jugal. 


inseparably ankylosed; anteriorly it abuts against the mesethmoid car- 
tilage and is in contact with the ethmoid and usually the vomer; pos- 
teriorly it abuts against the basisphenoid, with which it commonly 
becomes ankylosed before the animal is fully adult. The ascending 

*Iu fig. 9, which is a young skull, the presphenoid is covered by the orbitosphe 
noids, making it appear very much broader than it really is. 

Irom Amecameca, Mexico, with vault of cranium 

ma Meatus auditorius internus. 

7nb Mastoid bulla. 

n Nasal. 

of Optic foramen. 

OS Orbitosphenoid. 

pet Petrous part of periotic. 

pmx Ascending arm of premaxilla. 

ps Presphenoid. 

ptf Spheno-pterygoid fossa. 

s/ Apex of .sphenoidal fissure. 

so Supraoccipital. 

iv/ Squamosal. 

tb Superior face of tympanic or audital bulla. 

zmx Zygomatic root of maxilla. 


wings (vertical plates) of the palatines clasi) the sides of the prespheiioid 
iiiferioiiy, rising anteriorly. The ends of the vomer reach it also, clasp- 
ing it laterally, bnt never underlying it as in many mammals. The pre- 
sphenoid ends anteriorly in a somewhat thickened head, with a disk- 
shaped cavity iu front, which receives the hinder end of the mesethmoid 

The orbitosphe)ioids are a pair of thin horizontal shelves resting upon 
and invariably ankylosed to the upper border of the pres])henoid, and 
articulating anteriorly with the orbital plate of the frontal (fig. 9, o.«, 
and pi. 17). They are normally perforated near the anterior border by 
the optic foramen (tig. 9, of), but in Heterogeomys this foramen is incom- 
plete superiorly (pi. 17, fig. 1) except in the young. The antero-external 
corner sometimes jirotrudes through the sphenoidal fissure, bends up- 
ward, and slightly overlaps the j)osterior border of the descending wing 
of the frontal, appearing as a small scale in the bottom of the orbit. This 
is most often observed in young skulls. In Zygogeomys, Pappogeomys, 
and some forms of Thomomys the ascending tongue of the orbitosphe- 
noid completely closes the upper part of the sphenoidal fissure, excejit 
a small point at its apex, which is left as a permanent foramen (pi. 18, 
fig. 2), and becomes ankylosed to the frontal anteriorly and the alisphe- 
noid posteriorly (pi. 17, fig. 2). With these exceptions it does not 
appear in the parieties of the cranium, though it may always be seen 
crossing the sphenoidal fissure, which it divides into two parts. Ante 
riorly the orbitosphenoid invariably articulates with the upper surface 
of the presphenoid and the descending wings of the frontal, as already 
stated, and sometimes also with the palatine, maxilla, and posterior 
edge of the cribriform plate; posteriorly it often touches the edge of 
the alisphenoid, to which it becomes fixed in Cratogeomys, Orthogeomys, 
Pappogeomys, Zygogeomys, and some forms of Thomomys. . 

The relations of the orbitosphenoids anteriorly vary in the several 
groups and in some cases are exceedingly difficult to ascertain, owing 
to early ankylosis with the presphenoid. In Geomys hursariu.s the 
ascending wings of the palatine rise high on the sides of the presphe- 
noid and articulate broadly with the orbitospheuoids, but iu most 
forms it is uncertain whether or not the palatine is reached. The uncer- 
tainty is due to the impossibility of determining how far the orbito- 
sphenoid descends anteriorly below the top of the presi)henoid, with 
which it is inseparably fused. For the same reason it is uncertain 
whether or not the orbitosphenoids always reach the cribriform plate of 
the ethmoid. They seem to do so in all cases along the median line, but 
I have been unable, even in very young skulls, to find the place of sepa. 
ration anteriorly between the orbitosphenoids and presphenoid. In 
those genera in which the descending or orbital plates of the frontal do 
not meet interiorly behind the cribriform plate, tlio orbitosphenoids 
articulate broadly with the cribriform (as in Fappogeomys, Orthogeomys^ 
aucl Thomomys), 

JAN., 1895.] thp: skull. 49 

In Geoniys proper the orbitosphenoids are narrower than in any of 
the other genera, and do not reach the alisphenoids. In Heterogeomys 
and Platygeomys also they usnally fall short of the alisphenoid, though 
in extreme cases they sometimes cross the anterior edge of the 
alisphenoid. In Cratogeomys and Orfhogeomys they articulate with the 
alisphenoid anteriorly for a short distance, but do not follow the upper 
part of the sphenoidal fissure, though in Orthogeomys they sometimes 
send a tongue upward covering part of the fissure. In Pappogeomys 
and some species of Thomomys they go a step further, articulating 
firmly and broadly with the alisphenoid and normally closing the 
greater x)art of the sphenoidal fissure above the plane of the presphe- 
noid. Zygogeomys presents a still more extreme phase, the orbito- 
sphenoid almost completely closing the upi)er part of the sphenoidal 
fissure and ankylosing broadly with the alis])henoids. From what has 
been said it must be clear that the orbitosphenoids play a more 
important part than any other bones in determining the form of the 
floor of the brain case, for the reason that by their expansion or con- 
traction anteriorly they completely change the size and shape of the 
sphenoid fossa, which is the most conspicuous of the variable land- 
marks of the floor of the brain case, as may be §een on consulting i^l. 17. 

T\ie> frontals coalesce very early (i)robably before birth), forming a 
single large bone (fig. 8,/r) which constitutes the middle third of the 
upper surface of the skull and dips deeply into the orbits, where it 
makes important connections with the maxilla and other bones. It 
forms the roof of the olfactory chamber of the nasal cavity, and the 
roof and part of the side walls of the anterior segment of the brain case. 
The main body of the frontal articulates anteriorly with the ethmoid, 
nasals, premaxilla, maxilla, and lachrymals, and posteriorly with the 
parietals, squamosals, and alisphenoids. It is so extensively over- 
lapped by the alisphenoids and squamosals that when viewed from the 
outside it appears much smaller than it really is. 

The descending or orbital processes of the frontal (figs. 4, o/V, and 
9,/ro) reach far downward, burying themselves deeply among the bones 
of the base of the cranium and face. They articulate with the anterior 
border of the orbitosphenoids, clasp the sides of the presphenoid and 
palatines anteriorly, and articulate firmly with the maxillaries. Ante 
riorly, except in Thomomys^ Pappogeomys (fig. 56), and Orthogeomys, they 
completely encircle the cribriform plate of the ethmoid (with which 
they early unite by ankylosis) and meet in the median line below it, 
thus reaching around the olfactory lobes of the brain case and forming 
the floor as well as the roof and sides of the olfactory fossa. At the ijoint 
where the two arms come together in the median line, at the posterior 
base of the cribriform plate, a small opening is commonly left which 
remains as a perforating foramen passing obliquely forward and down- 
ward between the presphenoid and mesethmoid plate, and oijening 
anteriorly into the olfactory chamber of the nasal cavity immediately 
7433— No. 8 4 


behind the lower part of the fourth eudoturbiuals. In Thomomys (fig. 
61), and in the young of most of the other genera (as in Cratogeomys, fig. 
9, fro), the orbital plates of the frontal are separated interiorly by the 
orbitosphenoids. The variations in the form of the frontal are described 
further on (p. 05 and fig. 17). 

The ethmoid is a highly complicated bone occupying the posterior 
part of the olfactory chamber of the nasal cavity, which it completely 
separates from the brain case. No part of it appears on the outside of 
the skull. It maybe described under five heads : (1) the cribriform 
plate; (2) the mesethmoid; (3) the os planum; (4) the ectoturHnals, and 
(5) the endoturhinals. There is no apparent 'crista galli' in the Geoni- 
yidw. [The naso- and maxillo-turbinals are completely detached, and 
are described under the bones to which they are respectively ankylosed, 
namely, the nasal and jnemaxilla.J 

(1) The cribriform plate is a transverse i)erforated partition, separat- 
ing the olfactory fossa of the brain case from the olfactory chamber 
of the nasal cavity (fig. 9, cr). It is nearly circular in outline and 
slopes or curves forward from the base upward. Posteriorly, in most 
of the genera, its entire circumference articulates (and early anky- 
loses) with the frontals, which usually separate it interiorly from the 
orbitosphenoids, though the latter may always reach it near the me- 
dian line by pushing forward beneath the frontals. To its anterior 
face are attached the ectoturbinals, endoturbinals, and mesethmoid. 

(2) The mesethmoid bone, or perpendicular plate of the ethmoid, is a 
longitudinal median partition incompletely dividing the olfactory cham- 
ber into two parts ( fig. 7, me). Its superior border is firmly and insep- 
arably ankylosed to the frontal; its posterior to the cribriform plate. 
Antero-inferiorly it abuts against the cartilaginous mesethmoid, which 
latter reaches forward from the presphenoid and is embraced between 
the lateral wings of the vomer, completing the partition between the 
two sides of the olfactory chamber. The shape of the bony lamella 
varies in the different groups and seems to be quite constant in mem- 
bers of the same genus. In Cratogeomys (pi. 18, fig. 4), Orthogeomys 
(fig. 60), and Geomys proper (pi. 18, fig. 1), it is somewhat like a half 
crescent, with the base above, and the apex pointing to the end of the 
presj^henoid, the anterior border being convex downward, tn Platy- 
geomys it is similar, except that the upper part is strongly rounded 
anteriorly, the upper edge being shorter than that part of the lamella 
immediately below it (pi. 18, fig. 5). In Heterogeomys it is relatively 
small and strongly convex anteriorly (pi. 18, fig. 3). In Zygogeomys it is 
nearly rectangular and the front edge is nearly straight (pi. 18, fig. 2). 
In Pappageomys (fig. 57) it is higher than long, and its inferior border 
dips down between tlie wings of the vomer — a unique condition. 

(3) The OS planum is a thin sheet of bone wliich lines the posterior 
part of the olfactory chamber (fig. 10, op). It supports the endoturbi- 
nals and binds them together (as may be seen by consulting fig. 10 and 

JAN., 1895.] 



pi. 10, figs. 3, 4, and 5 of Geomi/s hursarius, Heterogeomys^ and Zycjogeo- 
mys). Inferiorly it articulates with the vertical lamella of the maxillary 
which lines the nasal passage, and witli the anterior ends of the ascend- 
ing wings of the palatines. Near its lower border (just below the fourth 
turbinal), it gives off a lateral shelf, which is firmly ankylosed to the 
outer side of the posterior third of vomer. In Cratogcomys its antero- 
inferior border is cut off" close to the turbinal folds, giving the latter a 

Fig 10.— LoDgitudal vertical median section of trout part of skull of Geomijs hursarius. Meseth- 
moid and vomer removed to show turbinated bones. 

1 Anterior i>alatine foramen. 

2 Inci.sive foramen. 

3 Vacuity in front of presphenoid (present in Geomys hursarius and tuza only. It is partly over- 

lapped posteriorly by the ascending wing of the vertical plate of the palatine, ap.). 

4 Presphenoid fcnestrum. Present in all species. 

5 Upper part of sjihenoidal fissure. 
H First or superior endoturbinal. 
2t Second endoturbinal. 

3< Third endoturbinal. 

it Fourtli endoturbinal. 

ap Ascending wing of vertical plate of palatine. 

/*• Frontal. 

mt Maxilio-turbinal. 

nix Maxilla (the upper pointer rests on the maxillary surface of the narial passage, the lower on the 

sawed body of the bone). 
n Nasal. 
nt Naso-turbinal. 
op Os planum. 
pi Palatine (the upper pointer rests on the palatine face of the narial passage, the lower on the sawed 

horizontal body of the bone). 
pmx Prcmaxilla. 
ps Presphenoid. 
vr Vomerine ridge of os planum (unites with the lateral wing of the vomer) . 

particularly neat and finished appearance (pi. 19, fig. 6). In Geomys 
hursarius, on the other hand, it falls directly downward from the first 
turbmal, projecting as a thin sheet considerably in front of the others 
(fig. 10 and pi. 19, fig. 3). 


(4:) The ectoturbinals * arise from the upijer and outer corners of the 
cribriform plate and occupy a small chamber at the maxillary root of 
the zygoma, incased chiefly by the frontal and maxillarybones. When 
the lachrymal is removed, they may be seen from the orbital side. 

(5) The endoturbinals * arise from the outer sides of the anterior face 
of the cribriform plate (on the inner side of the ectoturbinals) and ])ro- 
ject into the nasal chamber (lig. 10). They are four in number through- 
out the family. Their outer sides are continuous with and form a part 
of the OS planum. The first or upi^ermost is always the largest, longest, 
and most broadly expanded anteriorly. The others decrease in length 
from above downward, and are broadest in the middle or posteriorly. 
The fourth or lowermost is broader and shorter than the two middle ones. 
The first or uppermost is the only one that need be considered from the 
standpoint of variation of form in the several gi'oups. Its front border 
usually slopes strongly backward (from above downward), as in Flatygeo- 
mys, Cratogeomys, and Zygogeomys; but in Heterogeomys it is straight or 
slightly emarginate, vertical, and very broad, and carries with it the 
second fold (see i^l. 19, fig. 5). In Platygeoniys it is long and relatively 
slender, and its apex projects anteriorly behind the posterior border of 
the nasoturbinal (pi. 10, fig. 7). In Zygogeomys also it is pointed and 
projects far forward (pi. 19, fig. 1). In Geomys hursarius it is rather 
bluntly rounded (fig. 10, and pi. 19, fig. 3). 

The vomer is a long and narrow plate of bone, cleft above and bifur- 
cate posteriorly, which forms the lower part of the longitudinal verti- 
cal septum between the lateral chambers of the nasal cavity (fig. 7, v). 
It consists of a median plate and two wings. The median plate is 
embraced inferiorly between the wings of the vomerine sheath (which 
rises from the floor of the premaxilla and extreme anterior part of the 
maxilla). Superiorly it is split lengthwise from above, forming the two 
wings, between which the mesethmoid cartilage is received. These 
wings are narrowed j)osteriorly and reach the front end of the pre- 
sphenoid, which they clasp laterally, but they do not appear on the 
inferior surface of the presphenoid, as they do in most mammals. Pos- 
teriorly the wings of the vomer separate slightly and are not united 
inferiorly. On the outer side they are inseparably united with the 
OS planum just below the fourth endoturbinal, thus continuing ante- 
riorly the roof of the narial i)assage, which is here sharply separated 
from the olfactory chamber above. The vomer articulates with the 
premaxilla, maxilla, ethmoid, presphenoid, and palatines. 

ThOi pterygoids are more or less quadrangular vertical plates, forming 
the lateral walls of the posterior nares (figs. 4 and 7, pt). Anteriorly 
they articulate Avith the vertical plates of the palatines ; superiorly they 
are firmly ankylosed to the basisphenoid, and usually also with the 
posterior downward extension of the transverse arm of the alisphenoid. 

* These terms are adopted from Dr. Harrison Allen's admirable paper on the Eth.- 
moid.— (Bull. Mus. Comp. Zool., Cambridge, X, No. 3, 1882, 136.) 

JAN., 1895.] THE SKULL. 53 

They commonly develop a hamtilar process (figs. 4 aud 7, A), which 
curves upward and reaches or nearly reaches the audital bulla (except 
in Heterof/eomys). The inferior surface of the pterygoid is usually flat- 
tened, either horizontally or obliquely ; it may be of uniform breadth 
(fig. 11^), or much broader anteriorly than posteriorly (figs. 11^ and IV). 
It reaches its maximum length aud slenderness in Zygogeomiis (fig. 11'); 
its maximum breadth and shortness in Macrogeomys (fig. IP), The 
two arms may be divergent posteriorly, convergent posteriorly, or par- 

Fig. 11.— Principal tjpes of palatopterygoids. 

1. Zygogeoinys trichopus. 2. Oeomi/s lutescens. 3. Geomys bursarius. 

4. Heterogeomya hispidus. 5. Alcfbrogeomys heterodus. 

In the share they take in the formation of the palato-pterygoid plates 
on the roof of the niouth, and the manner of articulation with the pal- 
atine bones, the pterygoids present five types, as follows : 

(1) They completely surround the postpalatal notch like a horseshoe, 
meeting or so nearly meeting anteriorly that at most a narrow spicule 
of the palatine reaches the notch in the median line. This type occurs 
in the genus Zygogeomys only (fig. 11'). 

(2) They form the whole or practically the whole of the sides of the 
postpalatal notch, but are separated anteriorly by the full breadth of 
the notch itself. This is the commonest type and prevails in the genera 
Geomys nudCratogeomys (fig. 11'). 

(3) They are lingulate in shape and do not reach the base of the jiost- 
palatal notch, the palatine bones extending out a considerable distance 
to meet them. This is the ordinary condition in Geomys bursarius (fig. 

(4) They are very much reduced, forming only the terminal part of 
the palato-pterygoid plates, the palatine part of which is greatly elon- 
gated. This condition obtains in Heterogeomys (fig. 11*). 

(5) They are short, broad, and abruptly upturned, capping the ends 
of the very broad palatines. This type is restricted to Macrogeomys 
(fig. IP). 

The palatine bones contribute an insignificant part to the external 
surface of the skull (fig. 12, pi), but internally their connections are 
extensive and important (fig. 7, pi, and fig. 10, pi and aj)). They early 
unite (probably before birth) in the median line, forming a single bone, 
which may be described as consisting of a body, two vertical plates, and 
two lateral wings or external ptergoid plates. The body or horizontal 


part enters the roof of the mouth posteriorly, forming a wedge between 
the hinder part of the maxillaries, and never reaching further forward 
than the middle molars (fig 12, pi). This part is cut away posteriorly, so 
that its inferior surface is on two i)lanes. Anteriorly it is continuous 
with the plane of the bony pala'.e; posteriorly with the pterygoitls. 
The break in the palatines between these two i)lanes occurs suddeidy 
between the posterior molars, forming a step or pit on each side between 
the last molar and a median azygos iDrojection of the palate, which con- 
nects the two more gradually. Posteriorly the palatals may terminate 
oijposite the anterior end of the postpalatal notch (as usual m Crato- 
geomys), or they may extend out a short distance beyond the apex of 
the notch (as m Oeomys proper), or they may i^ush back still farther, 
forming more than half of the side walls of the notch (as in Hetero- 
geomys), or they may fail to reach the notch at all, the pterygoids com- 
ing forward to the median line (as in Zygogeomys). [See fig. 11 supra.] 

The vertical jilcites are tliin lamellae, which reach upward on each side 
from the body of the bone to the i)resphenoid, surrounding the middle 
section of the narial passage between the maxilla and pterygoid (tig. 
7,2)1)- Their upper borders reach the basisphenoid anteriorly and are in 
contact with the i^resphenoid for its entire length ; anteriorly they clasp 
the sides of the presphenoid and articulate with tlie ethmoid and 
frontal — the descending processes of the latter overlapping their ante- 
rior prolongations. The front border of the vertical plate of the pala- 
tine, on the side of the narial passage, articulates with the correspond- 
ing part of the maxilla; the hinder border with the pterygoid. In 
Gcomys bursarius the vertical plate rises anteriorly in an ascending iving 
which hugs the prespenoid anteriorly and articulates broadly with the 
orbitosphenoid, frontal, and maxilla (fig. 10, a.p). 

Posteriorly the body of the palatine sends oft", on each side, a lateral 
wing — the external pterygoid plate — which pushes its wjiy around behind 
the maxilla and along the inner side of the descending wing of the 
alisphenoid as ftir as the i^oint where the Litter is joined by the trans- 
verse arm of the same bone (immediately below the alisphenoid canal), 
and sometimes sends a spicule backward to the audital bulla (fig 12, epl). 
The external pterygoid plate of the palatine thus forms the outer wall 
of the pterygoid fossa inferiorl}^ It is completely overlapped exter- 
nally by the descending wing of the alisphenoid, except along its infe- 
rior margin, which projects slightly below the alisi)henoid, thus apx)ear- 
ing on the outer side of the skull (fig. 4, epl). 

The palatines articulate with the maxilla, pterygoids, alisphenoids, 
basisjihenoul, presphenoid, frontals, vomer, and ethmoids and some- 
times also within the orbitospheuoids and the tympanic bulla*. 

The maxilla is the largest, and after the ethmoid the most compli- 
cated bone of the skull, and comprises, roughly speaking, about one- 
third of the entire cranium (fig. 12, mx). It i)rimarily consists of two 
parts, which are firmly united by ankylosis in very early life (probably 


JAN., 1895.] 



before birth), forming a single strong bone for the support of the grind- 
ing teeth. It articnhites with nearly all the bones of the face and with 
those of the anterior segment of the brain case, as follows: Anteriorly 
with the premaxilla, ethmoid and lachrymals; superiorly with the pre- 
sphenoid and frontal; posteriorly with the palatines and alisphenoid, 
and externally with the jugals. The maxilla forms nearly the whole 
of the roof of the mouth, the palatines entering it merely as a wedge 
from behind. The densest and hardest part of the skull, after the 
floor of the premaxilla, is the median part of the maxilla between the 

FiQ. 12.— Under side of young .skull of Cratogeomijg merriami. (Specimen from Amecameca, Valley 
of Mexico.) 



VIS Mastoid process of squamosal. 

amx Alveolar border of maxilla. 

mx Maxilla. 



n Nasal. 



pi Palatine. 


Condyle of exoccipital. 

pmx Premaxilla. 


External pterygoid plate of 


pp Paroccipital process of exoccipital 


Foramen rotundum. 

pt Pterygoid. 



2itf Pterygoid fossa. 


Incisive foramen. 

smf Stylo-mastoid foramen. 


tb Tympanic or audita! bulla. 


"External auditory meatus. 

zmx Zygomatic process of maxilla. 


Mastoid bulla. 

molariform teeth. The infraorbital canal is deeply imbedded in the 
maxilla and is very long, reaching back from near the premaxillary 
suture on the side of the muzzle to the bottom of the orbit. In the 
Geomyidcv it never perforates the zygomatic root of the maxilla, but 
passes deeply behind it. 

The maxilla gives off anteriorly a vertical lamella, which rises from 
the median line of the tloor of the nasal chamber and projects forward 
a short distance into the posterior part of the vomerine sheath of the 
premaxilla (fig. 13, ms). It is split lengthwise to receive the posterior 


part of tlie median plate of tlie vomer, but the resulting wings do not 
spread apart as in the premaxillary part of the vomerine sheath. 

On each side of the nasal passage the body of the maxilla gives off 
a thin vertical plate or lamella, which may be termed the internal ver- 
tical plate of the maxilla. It forms a lining for the narial passage and 
articulates above with the lower edge of the os j^lanum of the endo- 
turbinal. The infraorbital canal passes for nearly its entire length 
between this thin plate and the main part of the maxilla. 

The premaxilla is a single bone in the Geomyidce (its two halves unit- 
ing before birth, fig. 12, pmx). It constitutes the greater part of the 
rostrum and forms the floor and lateral walls of the anterior half of the 
nasal chamber. Superiorly it embraces the nasals and articulates with 
the frontal and the maxillary root of the zygoma ; laterally it articu- 
lates with the outer side of the maxilla a little anterior to the plane of 
the infraorbital foramen; inferiorly it articulates with the maxilla 
posterior to the middle of the rostrum, and reaches far enough back- 
ward to inclose the incisive foramina (fig. 12, if) in all except Zygo- 
geomys trichopus. Anteriorly it is perforated on the median line by the 

Fig. 13.— Longitudinal vertical section of nasal chamber of Gratogeomys merriami. The vomer 
has been removed to show the vomerine sheath and anterior turbinated bones. 

mx Maxillary. 
n Nasal. 

1 Anterior palatine foramen. 

2 Incisive foramen. 
mt Maxilloturbinal. 

WIS Maxillary part of vomerine sheath (which 
passes anteriorly into the premaxillary 
part of the sheath). 

pnix Premaxilla. 

vs Vomerine sheath of premaxilla. 

anterior palatine foramen, which descends from the floor of the nasal 
chamber to the roof of the mouth, immediately behind the incisors 
(figs. 7, 10 and 13 '). On the inner side it supports the maxillo-turbinals 
and the vomerine sheath, which latter structure attains a high devel- 
opment in this group, particularly in Flatygeomys and Gratogeomys. 

The vomerine sheath (fig. 13, vs) is a double lamella rising from the 
floor of the premaxilla on the median line and projecting into the nasal 
cavity. It is elongated antero-posteriorly, reaching from the hinder 
end of the premaxilla forward over half or two-thirds the floor of 
the bone. Posteriorly it receives the anterior end of the corresponding 
(but very much smaller and narrower) part of the maxilla; superiorly 
it receives the median vertical iilate of the vomer. 

JAN., 1895.] 



The maxillo-turbinal, or inferior turbinated bone (figs. 7, 10, and 13, mt), 
is the lower of the two turbinated bones of the anterior half of the 
nasal cavity (the upper being attached to the nasal). It is nearly hori- 
zontal, though usually sloping downward posteriorly, and is attached 
to the middle part of the inner side of the premaxilla; its free posterior 
end projects slightly over the front of the maxilla. 

The premaxilla articulates with the nasals, frontal, maxilla, vomer, 
and ethmoid. 

The jugal completes the zygomatic arch, and is always restricted to 
the horizontal ])art, never reaching down posteriorly into the glenoid 
fossa, and never creei)ing up anteriorly toward the lachrymal (figs. 
9 and 12, j). But its variations in size and form are remarkable (fig. 14 
and pi. 13). In some species it is very large and broadly expanded 
anteriorly (fig. 11'); in others it is reduced to an insignificant splint, 
and the zygomatic arch is complete without it (fig. 14*'). It is com- 
monly larger and broader in the male than the female, and sometimes 

Fig. 14. — Left zygoma, showing several types of jugal. 
\. Platygeomystylorhinus. I 4. Geomysbtirsarius. 

2. Heterogeomys hispidus. 5. Cratogeomys perotensis. 

3. Macrogeomys hetc.rodus. I 6. Zygogeomys trichopus. 

varies greatly in species of the same genus and even in the same sec- 
tion. Thus, in Platygeomys it is greatly expanded in gifmnvrus and 
tylorhinus, and is slender throughout in planiceps. Similarly, in Crato- 
geomys it IS broad anteriorly in merriami, ful,vesce7is, and castanops, 
while in perotensis it is slender and small in every way. 

The lachrymal is a small L-shaped bone, consisting of a vertical scale- 
like part, which closes the vacuity between the frontal and maxillary 
root of the zygoma at the inner corner of the orbit; and a thickened 
horizontal part which projects outward from the frontal on the upper 
surface of the skull and articulates also with the maxillary root of the 
zygoma. Its distal end is sometimes elongated and slightly recurved, 
and projects freely over the corner of the orbit. The principal or ver- 
tical part of the lachrymal is grooved vertically on its outer side, just 
anterior to the orbital face, for the lachrymal duct which passes down 
into tlie nasal chamber. 

The nasal bones fill the interspace between the ascending arms of 
the premaxilla on top of the rostrum, thus completing the roof of the 
nasal cavity, which they slightly overhang anteriorly (figs. 8 and 9,m). 


They are commonly ankylosed together in middle life, and not infre- 
qnently become ankylosed to the frontal.s also. Their actual length 
varies greatly in the different species. They are shortest in Gratogeo- 
7nysestor and longest in Zygor/eomys triehopiis and Geomys tuza. They 
are commonly truncate wedge-shaped; the increase in breadth from 
behind forward may be gradual or abrupt. In the latter case the expan- 
sion is usually near the middle. In the Geomys tuza group the shai)e 
of the nasals is peculiar. They are very long and are constricted near 
the middle, giving them an hour-glass shape. In most of the genera 
{Geomys^ Gratogeomys, Platygeomys, Zygogeomyn) the nasals are nearly 
flat, though they are always more or less decurved anteriorly and 
rounded off laterally in front. But in some groups (notably in Hetero- 
geomys) they are broadly and highly arched anteriorly, giving them 
an inflated appearance. This elevated part of the nasal suijports the 
naked nasal pad or callosity. Inferiorly the nasals give oft" a descend- 
ing lamella, the nasoturhinal bone, which is elongated antero-posteriorly 
and is broadest behind. 

The nasals articulate with the premaxilla, frontal, and ethmoid. 

The tympa7io-2>eriotio capsule incompletely fills a broad gap in the 
posterior segment of the skull, between the basioccipital and squamosal 
(ligs. 4, 7, and 9). It is held in place by several bones with which its 
connection is more or less intimate, but is never ankylosed to any of 
them except in extreme age, when the mastoid process of the mastoid 
bulla sometimes unites with the mastoid process of the squamosal. Its 
principal stays are the exoccipital and the mastoid iDrocess of the squa- 
mosal, between which the mastoid bulla is firmly grasped posteriorly. 
In addition to these supports, the inner border of the auditalbnlla com- 
monly fits into a groove on the outer edge of the basioccipital, and the 
apex of the bulla rests against the base of the horizontal arm of the 
alisphenoid near its junction with the basisphenoid. The tympano- 
periotic mass as a whole thus has four normal attachments, two of whicli 
hold it firmly in place, while the others simply steady it in its position. 
In old age the lower edge of the squamosal sometimes reaches the upper 
side of the bulla and presses firmly against it. 

The tympano-periotic capsule consists of three parts, firmly ankylosed 
together: (1) the tympanic, or audital bulla; (2) the petrous, or periotic 
proper; (3) and the mastoid bulla. Of these, the mastoid is posterior 
to the others, both of which are inseparably ankylosed to its anterior 
face. The tympanic protrudes from the base of the skull, forming the 
audital hulUv. The petrous projects into the brain case and contains the 
organ of hearing. Xo suture or other line of demarcation indicates 
the exact i)lace of meeting of the mastoid with either the petrous or 
tympanic, but anteriorly the line of nnion between the two latter is 
always distinct. The three elements may be described as follows: 

(1) The tympanic or audital bulla is almost wliolly inferior, projecting 
from the under surface of the outer segment of the cranium between the 

.iAN.,1895.] THE SKULL. 59 

basioccipital aud squamosal (figs. 4 and 12, tb). Anteriorly it is bounded 
by the fonimen lacerum medium basis cranii, in front of which is the 
transverse bar of the alisplienoid. Superiorly it is separated from the 
squamosal by a long, irregular vacuity reaching upward and backward 
from the foramen lacerum medium to the tube of the external meatus, 
which latter articulates with the squamosal. Posteriorly it abuts against 
the mastoid process of the squamosal above, and the exoccipital below, 
and is continuous with the mastoid bulla. Externally it sends off at 
right angles a long tube which partly tills the postglenoid notch aud 
opens just behind the posterior angle of the zygoma (fig. 12, ma). This 
is the external auditory meatus (fig. 4^). The tube of the meatus 
curves forward and somewhat upward as well as outward, and forms 
the posterior boundary of the glenoid fossa, against which the condyle 
of the jaw strikes tliiring the to and fro movement of mastication. The 
adjoining upper part of the outer side of the bulla forms the inner side 
of the glenoid fossa. It is thus ai)j)arent that this fossa, while mainly 
in the squamosal, is completed posteriorly by the tympanic bulla. The 
inner side of the bulla fits into a longitudinal groove on the outer edge 
of the body of the basioccipital, and the extreme anterior end just above 
the entrance of the Eustachian canal rests against the horizontal arm 
of the alisphenoid, which sometimes, as in Cratogeomys, sends back a 
small tongue of bone to cover its apex. The canal for the internal 
carotid artery is absent. On the inferior surface, between the mastoid 
and tynq^anic bulhe, is a small oiiening, the stylomastoid foramen (fig. 
12, S7nf). The tympanic bulla arches over and protects the tympanum 
and the openings leading into the internal ear. 

(2). The petrous, or periotic i)roper, in which is lodged the organ of 
hearing, is not visible from the outer side of the skull, but is conspicu- 
ous on the inner side (figs. 7 and 9, pet)^ where it is saddled upon the 
tympanic capsule, which it does not completely cover, a considerable 
l)art of the bulla protruding anteriorly (figs. 7 and 9, tb). The line of 
demarcation between the two is always evident. The anterior border 
of the petrous begins near the middle of the inferior margin of the 
inner surface of the bulla and curves upward and forward to the front 
end of the ridge that separates the inner from the superior surface of 
the bone. On the outer side of this ridge it turns back, forming a deep 
reentrant angle, at the apex of which is a small foramen. The petrous 
is commonly described as a very hard bone. It is not so in the Geomyidw, 
but is soft and spongy, being made up of cancellous tissue like the rest 
of the tym})ano periotic capsule. It contains the cochlea (coiled in a 
compact cone of 4i turns), the semicircular canals, and the three small 
bones of the internal ear — the malleus, incus, and stapes. Tlie jjetrous 
may be described as presenting two surfaces, a superior and an inner. 
The superior surface is narrow, slopes downward from behind forward, 
and is scooped out lengthwise. It is more or less completely separated 
from the inner surface by a ridge, which in some forms is sharply 


marked ; in others is incouspicuous. This ridge i)resents various degrees 
of developmeut iu the different groups. It is rounded off in Platy- 
geoniys, hnt is elevated into a distinct crest in Crafof/eomys, Zygogeomys, 
Heterogeomys, and Geoinys proper (pis. 17 and 18), It usually reaches 
upward and backward to the upper part of the audital mass, but in 
Heterogeomys it fails posteriorly, but forms a sharply elevated ridge 
from the plane of the flocculus downward (pi. 18, fig. 3). The inner face 
of i\iQ, petrous is always perforated by the internal auditory meatus (fig. 
7^ and tig. i), ma)^ above which is a depression called the flocctdar 
fossa {Hg. 7^ and lig. 9, ,^). The _^occM/flr/0''>'S«' varies in size and form 
in the several genera. Its position is always above and posterior to 
the internal meatus, from which it is separated by an elevation which 
sometimes amounts to a strongly developed ridge (see pis. 17 and 18). 
The ridge is marked in Cratogeomys, but not iu Platygeomys, Heterogeo- 
mys, or Geomys proper. In Zygogeomys it is not only present, but a 
suiiplemeutary ridge bounds the floccular fossa posteriorly, leaving 
another depression behind it, so that the bone presents the appearance 
of having two floccular fossa? (pi. 17, fig. 2, and pi. 18, fig. 2). 

(3) The mastoid bulla forms the hindermost part of the auditory 
apparatus (fig. 4, mh). It appears on the outer side of the occipital plane 
as a more or less rounded subtriangular mass, convex posteriorly, with 
the base toward the median line and the blunt ^.i^ex {mastoid process 
proper, fig. 4, m) directed outward. It is grasped and held in place by 
the paroccipital process of the exoccipital below (figs. 4 and 12, pp), and 
the long mastoid process of the squamosal above (fig. 4, ms). The for- 
mer fits into a notch on the under side between the mastoid and audital 
bull re. The latter reaches far outward and curves down upon the head 
of the mastoid process, which it overreaches enough to effectually oppose 
the action of the exoccipital. The mastoid bulla, viewed from behind, 
differs considerably in form in the several genera, and presents specific 
differences also (pi. 15, figs. 3-7). It is short and rounded in Zygo- 
geomys and Geomys (particularly in the tuza series). It is strongly 
triangular in Macrogeomys doUchoeephalus ; triangular with a con- 
stricted and elongated neck in M. keterodus, and much produced 
laterally with the inferior border concave in Platygeomys. Internally 
the mastoid bulla is made up of fine cancellous tissue. 

The mandible is usually a large and heavy bone, strongly marked by 
processes and ridges for the attachment of the powerful muscles that* 
move it. To be understood, it should be studied as a part of the cut- 
ting and slicing machine, for it consists, on each side, of a curved 
beam or plate built expressly to carry the ponderous chisel-edged inci- 
sors and the series of parallel cutting blades of the lower molariform 
teeth. The two halves are joined together by an elongated symph3^sis 
which admits of a certain amount of movement, and the adjustment is 
aided by a transverse muscle which helps bind the jaws together above 
the posterior half of the symphysis. Each half of the mandible is 

JAN., 1895.] 

thp: skull. 61 

strongly and rather shortly curved upward longitudinally, and is 
broader behind than in front; it also curves outward. There is no 
separation into horizontal and ascending rami, although when viewed 
from the inner side the condylar and coronoidpart might be regarded as 
forming an ascending ramus. The outer side gives off" posteriorly, at 
right angles to its axis, a strongly defined angular process which is 
alwaysimportant and in some forms, particularly in Flatyf/eomys, attains 
enormous i^roportions (pi. 10, fig. 8). Between the angular process and 
condyle is a subglobular prominence which covers the root of the long 
incisor. The coronoid process is broad at the base anteroposteriorly; 
its apex is hamular and rises above the plane of the condyle. In some 
forms (notably in Platygeomys) a strong shelf-like ridge runs from the 
anterior base of the coronoid to the angular process. The masseteric 
fossa is always well defined and reaches anteriorly to the plane of the 
front of the i)remolar. On the outer side of the last two molars is a 
large and deep pit for the insertion of the principal part of the temporal 
muscle (pis. 1-7). The dental foramen enters the, ramus just behind 
this pit and just below the condylar process. Behind the symphysis, 
inferiorly, is a flange-like prominence for the insertion of the digastric 
muscle. The principal differences in the form of the mandible as a 
whole result from the amount of spreading posteriorly and the degree 
of development of the angular processes. The various types, as seen 
from below, are shown on PI. 10. In some cases the base of the angular 
process is notched anteriorly, as in Geomys mohilensis (pi. 10, fig. 2.) 


Throughout the Geomyidce, except in Pappogeomys, and some species 
of Thomomys, the form of the cranium as a whole, and the pattern of 
the sutures on the upper surface change greatly with age. The change 
marks the transition from immaturity to maturity — from the generalized 
type that stands for the group to tlie specialized type that bears the 
impress of the species. When the skull of a species fails to show 
marked differences with age, that species may be set down as a gener- 
alized type — one that is probably but little removed from the ancestral 
line. For this reason Pappogeomys hulleri is looked upon as very near 
the trunk line of the group. 

The principal changes in the form of the skull as a whole resulting 
from age are : The broadening out of the zygomatic arches, elongation 
of the rostrum, expansion of the squamosal, and development of the 
crests and ridges that come with maturity. The anterior or maxillary 
root of the zygoma at first slopes strongly backward in all species, and 
the arches themselves are narrower anteriorly than posteriorly (as is 
the rule in adults of Thomomys). With advancing age they spread apart 
anteriorly until in most species they are much broader anteriorly than 
posteriorly. At the same time the maxillary root stands out more and 
more squarely until it sometimes forms almost a right angle to the axis 



of the skull. Tlie remarkable growth of the squamosal has beeu already 
described. Before birth the ascending branches of the premaxilla 
end about on a plane with the nasals (sometimes anterior to it), but 
they soon push back over the frontals, attaining their permanent 
relations at an early age. The muzzle increases in length from birth to 
maturity. This may be roughly expressed in the growth of the nasals 
as shown in the accompanying figure (fig. 15). In a young skull of 
Zygof/eomys trichopus the nasals form 37 percent of the total length of 
the u])per surfiice of the skull, wiiile in an adult skull of the same spe- 
cies they form 44 i)ercent of the total. The frontal, like the inter- 
parietal, though to a less degree, suffers from the encroachment of the 
parietals, and in some species from the inordinate growth of the squa- 
mosals also. In young skulls the frontal is broad posteriorly and 

Fig. 15. — Zyijogeoinys trichojjus, showing changes with age. a, Yonng; b. yovmg ailult; c, adult. 

forms an important part of the roof of the brain case, as seen from above 
(figs.8, loff, and 16b). In old skulls it is reduced posteriorly, in most 
species, to a small wedge between the greatly expanded anterior extrem- 
ities of the parietals and squamosals (see pi. 1; pi. 15, fig. 2; and text 
tig. 15, c, for adults of same species figured in figs. 8, 15, a and 10, h). 

The changes in the suture pattern result mainly from the growth of 
the parietals both anteriorly and iiosteriorly, with consequent shrink- 
age of the interparietal, and the pi'ogressive development of the squa- 
mosal. The decrease in the size of the interparietal corresponds with 
the movement of the temporal impressions, whicli approximate with 
age, and in many species finally meet in a sagittal crest. The parietals 
not only tend to cover the interparietal by meeting posteriorly above 
it, but anteriorly they overlaji the sides of the frontal, altering its shape 
entirely. The progressive development of the squamosals in some 

JAN., 1895.] 



species, as elsewhere shown, is evou more remarkable than that of the 

Fig. 16.— Skull of very J'oiing Heterogeomys torridus Irom Motzorongo, Mexico (So. 63643). 
a, lower surface; &, upper surface. For key to bones see figs. 8 and 12. 


Nearly all the paired bones that meet in the median line become firmly 
ankylosed together before birth or in very early life. Those that are 
thus coossifled are the preniaxillaries, masillaries, palatines, parietals, 
frontals, and frequently the nasals also. Of these, all except the parie- 
tals and nasals are ankylosed before birth (see figs. 8 and 16). 

The single bones forming the basicranial axis are early ankylosed 
with the adjoining paired bones of the same segments. Thus the pre- 
sphenoid is inseparably united with the orbitosphenoids; the basisphe- 
noid with the alisphenoids and pterygoids; the basioccipital with the 
exoccipitals. The union of the lateral with the median elements of 
the sphenoidal segments occurs before birth; that of the occipital seg- 
ment later. The exoccipitals are always distinct in early life (figs. 12 
and 16), but soon become ankylosed with the basioccipital below and 
the supraoccipital above. The latter, except in a few species, is insep- 
arable from the interparietal. The parietals in adult life are commonly 
ankylosed with the squamosals. 


In external appearance the members of the family Geomyidw are very 
much alike, but in cranial characters they present several marked gen- 
eric; types. The skulls of these types ditler in size, massiveness, and 
degree of development of the crests, ridges, and processes from the 
small, thin, and smoothly rounded skulls of Geomys fexensis and bulleri 


to the huge angular crauiums of Platygeomys ffymnurus and Cratogeomys 
merriami; and the large, massive skulls differ in the breadth of the 
cranium and lateral production of the angle of the mandible from the 
extraordinarily broad and flat Platygeomys gymnunis to the long and 
narrow Orthogeomys scalops and Macrogeomys doUchocepliahis. The skulls 
differ further — and this is much more important — in the relative devel- 
opment and relations of certain bones which here assume proportions 
and conditions previously unknown. Most if not all of these remark- 
able extremes of form are clearly secondary modili cations resulting 
from the highly specialized types of dental armature possessed by the 
animals, as shown later. 

The parts of the skull that exhibit the widest A'ariation and play the 
most important part in giving to each type its peculiar impress or physi- 
ognomy are the zygomatic arches, the roof of the brain case, and the occiput. 
The individual bones that present the greatest range in size and form 
are the frontal, squamosal, jugal, pterygoid, and mandible. 

The zygomatic arch varies exceedingly in size, form, and the relative 
development of its comi)onent elements, according to its importance 
as a support for the jugal part of the masseter muscle. It may be small 
and slender, with the horizontal part reduced to a mere rod, as in Pappo- 
geomys buUeri (pi. 13, tig. 15) and Orthogeomys latifrons (t)1. 13, fig. 16), 
or it may be large and massive, with the angle and horizontal arm broadly 
expanded, as in Platygeomys (pi. 13, figs. 1 and 2), Cratogeomys (pi. 13, 
fig. 4), and Heterogeomys (pi. 13, fig. 20). The area for the attachment 
of the jugal part of the masseter muscle may be small and posterior 
(fig. 49, jo), or large and extending the full length of the outer side of 
the zygoma (fig. 50, jo). The arches may be small and narrow with their 
outer sides nearly parallel, as in Macrogeomys dolichocephalus (pi. 5) and 
Orthogeomys scalops (pi. 19, fig. 1), or they maybe massive, widely spread- 
ing, and broadly divergent anteriorly, as in Platygeomys (pi. 3) and 
Cratogeomys (pi. 2). The ratio of their breadth to the basal length of 
the skull varies from 54 j^ercent in Macrogeomys dolichocephalus to 
upward of 88 percent in Platygeomys tylorhinus, a difference of 34 
percent. They may be slightly or strongly decurved; the horizontal 
part may be lowest anteriorly as in Platygeomys gymnurus (pi. 13, fig. 2), 
or highest anteriorly, as in Macrogeofnys dolichocephalus (pi. 13, fig. 19), 
and the angle may be small (pi. 13, figs. 15, 16, and 24) or broadly 
expanded (pi. 13, figs. 1, 2, 4, 17, and 18). The expansion, which 
normally covers the antero- external angle, as in Platygeomys, Crato- 
geomys, and Heterogeomys (pi. 13, figs. 1, 2, 4, etc.) may be drawn 
backward so as to occupy the middle i^art of the horizontal arm, 
as in Macrogeomys costaricensis and dolichocephalus (pi. 13, figs. 19 and 
23). In the latter the zygomatic arch presents a i^eculiarity not 
observed in any other member of the grouj). It is narrow, broadly 
rounded antero externally, without the expansion of the angle common 
to Cratogeomys, Platygeomys, and Heterogeomys, but with a moderate 

JAN., 1895.] THE SKULL. 65 

expansion near the middle of the liorizontal arm. This expansion is 
wholly on the upper or orbital side, and is restricted to the maxillary 
part of the arch, wliicli here reaches innch farther back than usual. 
On comi)aring the arch caretully with that of 3facro(jeomys heterodus a 
curious explanation is suggested, namely, that in the extreme elonga- 
tion of the skull of M. dollchocephalus the anterior root of the zygoma 
has been moved forward (the post<;rior root being fixed), increasing the 
length of the maxillary arm, decreasing the breadth of the arch, oblit- 
erating the antero-external angle, elongating the laminar expansion on 
the orbital side, and carrying its highest point backward to or behind the 
middle of the orbito-temporal fossa (pi. 13, fig. 19, and text fig. 49). At 
the same time the upper anterior angle of the jugal has been rounded off, 
and the maxillary and squamosal arms of the zygoma have nearly clasped 
hands above it. Furthermore, the zygomatic arch as a whole has been 
lifted up by the main body of the masseter muscle and as a consequence 
the anterior end has been raised higher than the posterior (fig. 49, which 
should be contrasted with the corresponding view of Platygeomys gym- 
nurus, in which the front of the arch is drawn down, fig. 50). 

The form of the occiput as a whole varies considerably in the several 
groups. In the less specialized forms, such as Geomy.s texcnsis, arenarins, 
and breviceps, and Fappogeomys bullcri {pi. 15, fig. 5), it is rounded and 
bulges i)osteriorly to such a degree that the lambdoid suture is left a 
considerable distance in front of it. In Zygogeomys, Crafogeomys, and 
Geomyn hursarius and lutesceiis, the occiput is squarely truncated. In 
Heterogeomy.s (pi. 15, fig. 4), Macrogeomys (pi. 15, fig. o),and Orthogeomys 
it is rather high and slopes strongly forward; and in Hetc yog corny nit is 
particularly high above the mastoid bulhe. In Platygeomys it is de- 
pressed and elongated transversely and presents a unique appearance, 
the broad flange-like paroccipital processes curving strongly backward, 
defiiung laterally a deep basin-shaped cavity which is completed above 
by the overhanging lambdoid crest (pi. 15, fig. 7). 

The form of the frontal as seen from above varies greatly in the dif- 
ferent groups. lu Geoniys, CratogcomySj Platygeomys, and Zygogeomys it 
is narrow and is strongly biconcave between the orbits, with the orbital 
margins more or less thickened and raised, leaving a longitudinal 
depression or groove between them (fig. 17^). In Heterogeomys it is 
broad, flat on top, moderately biconcave between the orbits, and shield- 
shaped posteriorly, owing to the elevated temporal ridges ; but the 
orbital margins are not rounded, thickened, or raised (fig. 17^). In 
Macrogeomys it is moderately broad and deeply constricted between 
the orbits posteriorly. Immediately behind the constriction it exi)ands 
abruptly at right angles to its axis, forming well-marked postorbital 
processes which are capped by the apex of the alisphenoid and partly 
overlapped posteriorly by the squamosal (fig. 17^). In Orthogeomys it 
is remarkably broad throughout and is not constricted between the 
orbits (fig. 17''), though the peculiar inflations at the anterior corners 
7433— No. 8^—5 



[NO. 8. 

of the orbits in 0. grandis produce the appearance of a constriction 
behind them. 

The juf/al varies in size and shape from the large and greatly 
expanded i^late that forms the major part of the outer side of the zygo- 
matic arch in Flalygeomys iylorldnus (pi. 13, tig. 1), to the rudimentary 
splint or scale that adheres to the inferior side of the zygoma in Zygo- 
geomys trichopiis, the arch being complete above without it (pi. 13, 
fig. 24). 

Fig. 17. -Types oi frontal. 

1. Cratogeomys merriami. 3. Macrogeomys heterodus. 

2. Heterogeomys torridus. 4. Orthogeomys scalops. 

a?«, apex of alisphenoiil ; I, lachrymal; wixz, luasillary root of zygoma; n, nasal; iimx, ascending or 
nasal branch of premaxilla; sq, squamosal. 

The variation in the squamosal is hardly less extreme. Throughout the 
genus, except in the most generalized forms, this bone exhibits a singu- 
lar tendency toward expansion. In Geoniys proper the tendency is 
restricted to a slight overlai)ping of the postero-lateral moiety of the 
frontal and lower edge of the parietals. But in the genus Crato- 
geomys its ambition in this direction is not satislied until the whole of 
the posterior half of the cranium is covered. In Cratogeomys merriami 
as the animal grows old the upper edges of the squamosals gradually 
creep up over the parietals until the latter are comjiletely arched over 
and concealed, the squamosals actually meeting above them along the 
median line. lu doing this the squamosals cover the posterior part of 
the frontal as well as the whole of the parietals and most of the inter- 
parietal, and curve up posteriorly to take part in the formation of the 
lambdoid crest for its entire length, thus roofing the brain with two 

JAN., 1895.] THE SKULL. 67 

distinct layers of bone, the npper of which on each side, consisting of 
a single bone, overlaps in whole or in i^art five bones of the lower layer 
(frontal, parietal, interparietal, supraoccipital, and alisphenoid). The 
object of this unique arrangement is not only to furnish a brace to the 
zygoma, to which the powerful masseter muscles are in large part 
attached, but also to strengthen the vault of the cranium where the 
huge temporal muscles take origin. The various steps in the develop- 
ment of this extraordinary condition can be distinctly traced in the 
series of skulls of dift'erent ages of Cratogeomys merriami collected by 
Mr. ISelson in the Valley of Mexico. In Platygeomys another condition 
prevails, the squamosal expansion being chiefly away from the median 
line. On the inner side it overlaps the lower part of the parietals as 
usual; it then extends outward in a broad shelf, carrying the squa- 
mosal root of the zygoma far beyond its normal position, and spread- 
ing outward and backward so as to completely roof over the post- 
glenoid space, behind which .it pushes still further outward and over- 
reaches the extreme end of the transversely elongated mastoid. In 
Platygeomys gymnurus, tylorhinns, and planiceps the lateral expansion is 
so excessive that the breadth of the cranium across the squamosals 
posteriorly is actually greater than the breadth across the widely 
sjjreading zygomatic arches (pi. 3). 

The pterygoids vary surprisingly in size, form, and the extent to 
which the inferior surface enters into the lateral walls of the post- 
palatal notch, as already shown (pp. 52-53, and fig. 11). In Zygogeomys 
they are long and slender and encircle the notch like a horseshoe, meet- 
ing or nearly meeting in the median line behind the palate (pi. 14, fig. 1). 
In most species of Geoniys, Cratogeomys, Pappogeomys, and Orthogeomys 
they are more or less parallel plates forming the greater part of the walls 
of the notch but not approximating anteriorly (pi. 14, figs. 7, 11, 13, 
15). In Gconiys hursarins they are more posterior, and taper to nearly 
a point behind, being Ungulate in shape (pi. 14, fig. 2). In Macrogeomys 
they are short and broad and bend abruptly ujjward, capping the ends 
of the short and broad palatines (pi. 14, fig. 3). In Eeterogeomys they 
are small, and simply form the narrow ends of the elongated posterior 
arms of the palatines (pi. 14, fig. 12). 

The mandible is relatively small and light in Geomys. It is large 
and massive in Cratogeomys, Platygeomys, and the remaining groups. 
It is long and narrow, with short truncate angular processes, in Macro- 
geomys dolichocephalus (pi. 10, fig. 7). It is broadly spreading, with 
greatly elongated angular processes, in Platygeomys gymnurus (pi. 10, 

tig. S). 

The degree of development of the angular processes is correlated 
with definite types of molariform teeth, and afi'ords a key to the domi- 
nant movement of the jaw in mastication, the so-called 'grinding move- 
ment' being very different in the species with and those without the 
greatly elongated processes. Where these processes reach their highest 


development, as in Platygeomys (jymnurus (pi. 3 and pi. 12, fig. 8, and 
text figs. 53 and 54) the posterior part of the masseter muscle, arising 
from the jugal and squamosal arm of the zygoma, is correspondingly 
large and effective; and since the direction of its fibers is nearly trans- 
verse to the axis of the skull, it is evident that the resulting movement 
of the jaw must be largely lateral. If the two parts of the masseter 
contract simultaneously, the resulting motion of the jaw would be 
oblique; if they contract independently, a to-and-fro movement would 
alternate with a side wise movement. 

In the species in which the lateral production of the angle of the 
jaw is reduced to a minimum, as in Macrogeomys dolichocephalus (pi. 5 
and pi. 12, tig. 7; and text figs. 51 and 52) the i^osterior part of the 
masseter nmst be relatively unimportant, and the principal movement 
must be to and fro. That this is really the case is shown by the greatly 
restricted area of attachment for the jugal end of this part of the muscle 
(fig. 49 Jo), and also by the character of the teeth. As would be 
expected, the crowns of the molars are broader antero-posteriorly than 
in the gymnurus group, and the tooth row on each side is bowed down- 
ward—the crowns of the upper series as a whole being convex, the 
lower concave, antero-posteriorly (fig. 46). Moreover, the obliquity of 
the plane of contact of the upper and lower series is less in dolicho- 
cephalus than in gymnurus (see figs. 52 and 54,/).* 

* The types of molariform teeth coordinated with the two principal types of jaw 
movement, and hence secondarily with the development of the angular processes, 
are discussed at greater length under the head 'Mechanism and Dynamics of the cut- 
tiiuj machine' (pp. 93-97). 




The dental formula of the Geomyid(e is the same throughout the 
family, as follows : i ., , c tj? pm j, m o X 2 = 20 

All of the teeth of the Pocket Gophers are simple rootless * tubular 
prisms, closed at the top aud open at the base. In life the lower part 
is filled with a soft, pulp-like substance, supplied with blood vessels 
which replenish the tooth from below, enabling it to grow as long as 
the animal lives. The hardening of the pulp within the tooth forms 

Fig. 18. — Outline of skull of Plalygeomys gynuivrns, showing teeth in situ. 

the dentine and osteodentine; the enamel and cement are deposited on 
the outside. In the adultt the crowns of the teeth are never compli- 
cated by infoldings of the enamel ; the enamel never envelops the prism 
continuously and never dips into the interior, but is always attached 
to the outside in the form of vertical bands or plates like the staves on 

** Althougli the teeth have no true roots, it is convenient to speak of the basal or 
growing end as the root. The term is u.sed in this sense in the present paper. 

tThe enamel caps of the young teeth, and changes in the enamel pattern due to 
immaturity, are fully described under a se2)arate heading (p]). 83-8G). 




[NO. 8. 

a barrel (pi. 10, fig, 12). The number ofeuamel plates on eacli tooth 
varies from one to four. When the tooth is looked at from the side, 
the alternating bands of enamel and cement are found to extend ver- 
tically from base to crown ; and since the tooth is constantly worn 
down from above and as constantly replenished by growth from below, 
its original form is preserved and no sensible change in the enamel pat- 
tern takes place. 


The incisors are long and heavy, with trenchant, chisel-like edges 
(figs. 18 and 19). Their massiveness varies greatly in the different genera. 
The upper incisor is shortly curved in a single plane, forming a little 
more than a complete semicircle, and its root rests either in the ui)per 
part of the interspace between tlie divaricating roots 
of the premolar and first molar, as in Plafygeomys 
(fig. 18), or directly above the root of the first molar, 
as in some of the other genera. The lower incisor is 
much longer, less shortly curved, and does not form 
a complete semicircle. It passes backward beneath 
and on the inner side of the molars, its own root rotat- 
ing outward in a partial spiral like the beginning of 
the twist in a ram's horn, and terminates in a thin 
capsule of bone on the outer side of the condylar proc- 
ess. The lower incisor is thus considerably longer 
than the greatest length of the jaw, from which it 
projects at both ends. 

Both upper and lower incisors have their anterior 
faces covered with a plate of enamel, the edges of 
which are bent back over the sides of the tooth far 
enough to hold it securely (fig. 20, a, h, and fig. 24) 
so that it can withstand, without danger of loosening, 
the great strain to wiiich it is subjected in cutting 
hard roots. 

On the inner side of the tooth the inflexed border of the enamel is 
beveled (fig. 20, a) ; on the outer side it retains its normal thickness 
(fig. 20, b). The inner edge of the tooth is squarely angular or nearly 
so, while the outer edge is always broadly rounded (figs. 20, 21, 22). In 
the lower incisor the front face of the tooth is always flat or nearly so 
(fig. 24) ', in the up])er incisor it is flat in Macrogeomys and Jleferogeomys 
(fig. 20), nearly flat or twice convex in Cratogeomys (fig, 21^ and ^), 
Platygeomys (fig. 21^), and Fappogeomys (fig. 21,*); and thrice convex in 
Geomys proper (fig. 22^ and ^) and Zygoyeomys (fig. 22^), 

The enamel face of the upper incisor is invariably marked (except 
in some species of Thomomys) by a conspicuous longitudinal groove or 
furrow, resulting from an infolding of the enamel, A second and much 
smaller groove is sometimes present also, always near the inner edge 
of the tooth. The form and position of the grooves vary in the difl'er- 

Fio. 19. — Incisora of 
Platygeomys gymnurus 
seen from behind, a up- 
per; 6 lower. 

JAN., 1895.] 




ent species; there is also considerable range of individual variation.* 
Five types of siilcation prevail, as follows : 

Bisnlcafe se?(e.s; 

Principal sulcus on oM/er side of median line Geomys 

Principal sulcus on inner side of median line Zygogeomys 

Unisulcate scries: 

Sulcus median or slightly on inner side of median line; rather broadly 

open Craiogeomys, I'laty geomys, Fappogeomys, Orthogeomys 

Sulcus at junction of inner and middle thirds; usually rather narrow and 

deep Heterogeomys, Macrogeomys 

Sulcus close to inner side or absent Thomomys 

In Gcomi/s proper the principal sulcus is decidedlj^ on the outer side, 
and the small inner groove is about one-fourth or 
one-tifth the distance from the inner edge to the prin- 
cipal sulcus; it is nearer the inner border in the tuza 
series (flg. 22^) than in tlie hnrsarius series (fig. 22^). 
In Pappogeomys there is only a single groove (fig. 
21''), and it is median or nearly so, as in Cratogeomys, 
and very deep, Avitli the convexities on both sides 
strongly rounded. 

In Zygogeomys (flg. 22") the principal sulcus is 
median or slightly on the inner side, and the fine 
inner sulcus is ow the convexity of the enamel about 
one-third the distance from the inner side to the me- 
dian sulcus. It is not so near the inner side as in 
Geomys proper. In tbe latter the inner convexity is 
flatter and the small sulcus is on its inner side instead 
of on the convexity itself. 

In Heterogeomys and Macrogeomys (flg. 20) the 
groove is always far on the inner side and some- 
times wholly within tbe inner third. As a rule it is 
deeper and more abrupt than in the other genera, 
and the face of the tooth is flatter. 

In Cratogeomys and Platygeomys (flg. 21) the groove, as seen by the 

" The exact position of the principal sulcus varies not only in individuals of the 
same sjiecies from the same place, but even on the two sides in the same skull. Thus 
in Cratogeomys merriami and Platygeomys gymnurus of the unisulcate series it is 
usually on the inner side of the median line, but several skulls of each species are 
at hand in which it is median on one or both sides. Similarly, in Geomys bnrsarins 
and tiiza of the bisulcate series, its distance from the outer side of the tooth is some- 
times noticeably different on the two teeth. Its exact position therefore can not be 
relied upon as a character in distinguishing species, though its approximate position 
is important 

Many of the unisulcate teeth show, when examined closely, a faint inner groove 
in addition to the deep median furrow. The presence of this indistinct sulcus seems 
to be purely fortuitous, occurring here and there irrespective of sex, age, or species, 
sometimes on one side, sometimes on both, and is of no value whatever as a char- 
acter. Another fortuitous variation is the occasional presence of a line bead in the 
median sulcus. When present at all it is rarely symmetrical on the two teeth. 

Fig. 20. — Transverse 
section of upper in- 
cisor in the unisulcate 
species iii which the 
sulcus is strongly on 
the inner side. (1) 
Macrogeomys dolicho- 
cejjhftlus; (2) Hetero- 
geomys hispidus; (3) 
M. costaricensis; (4) 
M. cherriei (showing 
enamel face and single 
sulcus), a inner end of 
enamel plate; h outer 
end of enamel plate. 



unaided eye, ordinarily appears to be median j but when the tootli is 
magnified it is nearly always found to lie sliglitly on the inner side. 

Pig. 21. — Tran.sverse section of upper incisor 'Fig. 22. — Transverse section of upper incisor 

in the unisulcate .species in wliicli the sul. in bisulcate series — 

CU8 is median or nearly median — (1) Zygogeomystrichopus. 

(1) Cratogeomys merriami. (2) Oeomys burcariug. 

(2) Platygeomys gymnurus. ■ (3) Geomys tuza. 

(3) Cratogeomys pcrotensU. 

(4) Fap2>ogeomys bulleri. 

It sometimes difters noticeably in position in the two incisors, and in 
some specimens of C. merriami is further away from the middle than 

In Orthogcomys the groove is on the inner side, but is usually so 
widely open that its outer side reaches the median line. 
In Thomomys the groove is close 

to the inner edge of the tooth (fig. 

23) or absent. It is usually j)res 

ent, though sometimes very small 

and shallow. In a few sijecies it is 

deep and strongly marked, as in 

T. monticola Allen. 
The outline of the incisor in 

cross section varies in the differ- 
ent species. In some forms the anteroposterior diameter exceeds the 
transverse; in others the transverse equals or exceeds the antero- 
posterior. Usually the outer side of the tooth is an even curve from 
the point where the infiexed border of the enamel stoj^s, to the posterior 
convexity of the tooth, but this is not always the case. In the upper 
incisor of Cratogeomys oreocctes, and the lower of C. merriami, the 
outer side is emarginate, forming a distinct bevel immediately behind 
thereflexed enamel edge (fig. 21, h). 

Fig. 23. — Transierse 
section of upper incisor 
of Thomomys douglasi 
showing shallow sulcus 
close to inner side of 

Fig. 24.— Transverse 
section of lower incisor 
of Cratogeomys jnerri- 
ami: byhexe] on outer 


The premolars are double prisms, like a figure 8 in transverse section 
(fig. 25 and pi. 16, figs. 8, 12, and 13). Their crowns are worn obliquely 
to the axis of the tooth, hence the prisms are of unequal length ; the 

JAN, 1895.] THE PREMOLARS. 73 

posterior prism is longest in tlie upper premolar and the anterior in the 
lower. In size the two prisms of the upper premolar are subequal or 
the anterior is only slightly smaller than the posteriory in tbe lower, the 
anterior is commonly considerably narrower and more elongated antero- 
posteriorly. In form both prisms of the upper premolar and the pos- 
terior of the lower are transversely elliptical like the molars; but the 
anterior prism of the lower premolar is cylindrical or subcylindrical. 
Its transverse section is more nearly circular in Zygogeomys trichopiis 
and the Geomys bursarius series than in the others. In Macrogeomys 
cherriei it is more elongated transversely than usual in the group. 
The neck connecting the anterior and posterior i^risms is usually on or 
near the median line of the tooth, but in the upj^er premolar of Hetero- 
geomys hispidiis it is decidedly on the inner side. 

The premolars are larger than the molars, and the lower premolar is 
the largest of the molariform series (fig. 26). The upper premolar is 
implanted very obliquely and invariably s?02)es strongly backward from 
root to crown, the vertical plane of the root being far anterior to that 
of the crown. The lower premolar is strongly curved ; it is always con- 
cave anteriorly and convex posteriorly. It is implanted vertically or 
nearly so, thougli its root curves forward. The upper premolar is decid- 
edly longer than the lower in the genus Geomys (both in Geomys proper, 
comprising the bursar ius-tuza series, and in 
the Papiyogeomys biilleri series); the two are 
subeqnal in all the other genera. The shaft 
of the upper premolar may be either straight or 
curved. When curved it may be convex 
forward or concave forward. It is straight in 
Geomys lutescens, but decidedly concave an- , ^'«- ^^-Crowns of upper and 

, ' "^ lower premolars of Macrogeomys 

teriorly in all the other species of Geomys doUehocephaius : a upper, 6 
proper and in Fapimgeomys and Orfhogeomys ; ^*^''^®'"' 
it is strongly or moderately convex anteriorly in Cratogeomys and 
Macrogeomys^ and faintly convex or nearly straight in Reterogeomys, 
Zygogeomys, and Flatygeomys. In the latter genera it is commonly 
straight in the young and slightly curved in the adult. 

The length of prism of the upper premolar in G. bursarius, turn, and 
mobilensis is at least one-third greater than the total length of the tooth 
row on the crowns (fig. 26^) ; in G. texensis it about equals the length 
of the tooth row. Various intermediate conditions occur in the other 
species. The length of the upper premolar with reference to the 
molars affords two series: (1) in which the premolar and m' and m^ 
are of about the same length (comprising G. bursarius and most of the 
species in the other genera, fig. 26 1 and '^); and (2) those in which the 
premolar is decidedly longer than m' and ni^ {G. tiiza and mobilensis 
and Pappogeomys bulleri, fig. 26^). The length of the upper and lower 
premolars with reference to each other also affords two series : In the 



[NO. 8. 

genus Geomi/s the lower is much shorter tliau the upper (fig. 26^); in 
the otlier geuera {Crafogeomys, Heterogeomys^ and Zyyogeomys) the two 
are subequal or the lower is slightly the longer (fig. 26^ and ^). 


The true molars, except the last upper one (m"), are simple single 
tubular prisms, elliptical in transverse section. The last upper molar 
is a single prism in some forms; a double prism in others. In both 
upper and lower series the posterior molar is the shortest tooth (fig. 20). 
In the lower series the teeth are successively shorter from jireinolar to 
last molar. In the upper series the premolar may or may not be longer 
than the first molar; the first and second molars may be subequal or 
either may be. slightly longer than the other. As a rule throughout 

Fig. 26. — Type.s of molariform teetli (seen in profile) ; 

1. Heterogeomys hispidus. 

2. Cratogeomys merriarni. 

a upper series; b lower series. 
3. Geonigs tuza. 

the group, the first and second upf»er molars are as long or nearly as 
long as the premolar. This is the case in Geomys bursarius; but in 
other species of Geomys proper {fuza, breinceps, and texensh) and in the 
genus Pappogeomys they are very much shorter. In Pappogeomys 
bulleri and the Geomys tuza series the longest upper molar is only about 
two-thirds the length of the premolar, and nr'' is only half as long as the 

In the lower jaw the molariform teeth are successively shorter from 
before backwards, but diversity prevails in the relative lengths of the 
several teeth comprising the series. Thus in Heterogeomys Jtisjndns m.^ 
is but little more than half the length oi pm; while in other species 
it is more than three-fourths. The relative length of the individual 
molars vaiies in the different species and is subject to considerable 
individual variation also. 

The last upper molar is always the largest of the true molars. Its 
prism may be either single or double, or incompletely double; when 
double it nearly equals the premolar in size of crown, but never in 
length of shaft. It is invariably the shortest tooth of the upper series, 

JAN., 1895.1 


aud ill some species is as sliort as the last lower molar. It always 
curves backwards and the curvature is sometimes so great as to form 
the arc of a small circle. When a double prism, the posterior prism is 
always much narrower than the anterior. For purposes of classifica- 
tion m' is by far the most important tooth in the skull, its size, shape, 
form of crown, and enamel pattern furnishing characters of much value, 
as will be seen later. 

The last lower molar is ordinarily the shortest tooth in the skull, aud 
is always curved— the concavity posterior. In addition to the curvature, 
it is implanted obliquely, sloping- strongly backward from crown to 
root, the vertical plane of the root being far behind that of the crown. 
Its root is also rotated backward and inward, enabling it to lie flat 
against the inner side of the incisor, which passes between the roots of 
m2 aud m.T (fig. 41). Owing to the strong slope of the shaft of m:,, the 
crown is always truncated very obliquely to the axis of the tooth (fig. 18). 

The prisms of the intermediary molars in both jaws invariably curve 
outward, so that their outer borders are concave and inner borders 
convex. The curvature is stronger in the lower than in the upper 
series, and strongest in m,, whose root stands further outward (away 
from the median line) than any other in the series. The outer borders of 
the prisms are shorter than the inner borders, hence the open root-ends 
of the teeth always face obliquely outward. The anteroposterior 
curvatures of the prisms of the intermediary molars above and below 
take the same direction in each jaw, but vary in degree in the different 
genera and sometimes in species of the same genus. All of the superior 
molars curve backward from crown to root; the inferior intermediary 
molars curve forward from crown to root. In the genus Geomys the 
aiitero-posterior curvature of m' and m2 is so slight that their prisms may 
be described as essentially flat (fig. 2G^). If any curvature is apparent, 
it is backward in m' and forward in m2, in accordance with the rule. In 
Zyyof/eomys and Heterogeomys the curvatures are slight; in Orthogeomys 
they are marked, and in Macrogeomys, Cratogeomys, and Flafygeomys 
they iire very strong, m' and m'^ curving strongly backward and mj and 
m2 strongly forward (fig. 26^ and^). 

In addition to the curves described, the molar prisms are always 
more or less twisted on their axes. If the teeth were long enough these 
twists would result in spiral curves. 

The axes of the elliptical crowns of the intermediary molars are in a 
general way transverse to the axis of the skull; but they rarely stand 
out at right angles. As a rule they slope obliquely forward or obliquely 
backward. When the crowns of the upper molars slope backward from 
the median line the crowns of the lower molars are transverse or slope 
forward, and rice versa. The axis of the crowns of m' and m^ normally 
slopes backward in Geomys, Pappogeomys, and Cratogeomys; it is nor- 
mally transverse or slopes forward in Platygeomys, Orthogeomys, Macro- 
geomys, Heterogeomys, and Zygogeomys. 



[NO. 8. 

Tig. 27. 

-Types of ibrm of crown of last 
ujiper molar (m^). 


The form of the last upper molar affords excellent characters. In its 
simplest type, as in the genus Geomys (comprising both the tuza series 

and the texensk-hur sarins series) it is 
a single prism and the shape of the 
crown varies from suborbicular to sub- 
triangular (figs. 27 ^ and 33). In Pap- 
pogeomys (fig. 27 -) the form of the tooth 
is similar except that there is a decided 
emargination on the outer side, ante- 
rior to the middle, behind which the 
prism is abruptly narrower. This is 
the first step in the formation of the 
'heel' or posterior lobe, which is so 
conspicuous in Orthogeomys^ Heteroge- 
omys, and Macrogeomys (fig. 27^ and '^). 
In the genus Cratogeomys the tooth 
is partly converted into a double prism 
by a vertical groove on the outer side 
(fig. 27"*). This genus presents the widest latitude of individual varia- 
tion known in the family, indicating that the tooth is in a transition 
state and has not yet attained a condition of stable equilibrium. 

It is much more variable in Cratogeomys than in Platygcomys. Taking 
both genera together the crown presents all sorts of intermediate pat- 
terns, from a form in which the posterior prism is hardly more differen- 
tiated than in Pappogeomys hullerl, to forms having this prism produced 
to such a degree that the superficial resemblance to Hetcrogeomys is 
marked (tig. 35). But it lacks the stability of form and fixity of enamel 
pattern characteristic of the members of the latter genus. 

The variation is greater in the adult than the young, as would be 
expected from the increased obliquity of the crown with reference to 
the axis of tlie tooth in advanced age, and naturally is most marked in 
the length and form of the heel. Sometimes in old age the crown is 
worn so obliquely that the heel actually overhangs, acquiring an exag- 
gerated length very different from its transverse section (as in fig. 28, d). 

1. Geomys breviceps. 

2. Pappogeomys hulleri. 

3. Platygeomys gymnurus. 

4. Cratogeomys estor. 

5. Zygogeourys trichopiis. 

6. Macrogeomys dolichocephalus. 

7. Macrogeomys heterodus. 


Fk!. 28. — Varlatious in crown pattern of ni'' in Cratogeomys fulvescens. 

In Cratogeomys fulvescens (fig. 28) the variations in form and enamel 
pattern of crown are pronounced, but most of them are easily reducible 
to one or the other of two types: (1) An obcordate crown, deeply 
notched l)etween the prisms on the outer side, with the axis of the pos- 
terior loop or heel nearly transverse aiul the outer enamel plate reduced 

JAN., 1895.] 


to a small U-sbaped piece protectiug the sulcus (tig. 2S,a)', aud (2) a 
more or less subtriaugiilar or eveu trefoil-shaped crown with the axis 
of tiie posterior h)op very oblique (slopiug strongly backward as well 
as outward), and the outer enamel plate more or less elongated (fig. 
28, c, (1). In form the second is easily derived from the first by a slight 
backward rotation of the transverse axis of the posterior loop. Regard- 
ing the shape of the crown as more or less subtriangular, the apex of 
the triangle is always toward the median line of the skull and the 
notch or emarginatiou always on the outer (buccal) side. Cratogeomys 
castanops (fig. 20) stands somewhat apart from the other species. The 
double character of the prism is not well marked; the posterior part 
of the crown is rather broadly rounded, the lateral enamel plates are 
rather short, and the inner one is situated far back. Both tend to 
disappear in extreme age — doubtless from atrophy of the enamel organ. 

Fig. 29.— Variations in crovf n pattern of m^ in Cratorjcomys castanops. 

In the genus Flatygeomys the crown is snbtriangular, narrow behind 
the anterior prism, and the axis of the heel is normally anteroposterior, 
as in Fappogeomys (fig. 27^). 

hiMacrogeomys, Hcterogeomys, and Orthogeomys (fig. 34), the tooth is a 
double prism, the anterior and posterior moieties of which are separated 
by a groove or depression on each side — that on the outer side being 
invariably the deeper, that on the inner side being in rare cases obso- 
lete. The posterior prism is always narrower than the anterior (the 
narrowing is chiefly on the onter side), aud its anteroposterior diameter 
is usually greater. The crown as a whole is thus longer than broad, 
and is composed of two parts or lobes: an anterior which is broader than 
long (being transversely elliptical, like the other molars); and a narrow 
posterior lobe or 'heel' which is commonly longer than broad, and 
varies in form and proportions in the different species. 

In Heterogeomys the grooves on the two sides are nearly oi:)posite, and 
the anterior iirism is narrowly elliptical. In Orthogeomys und Macroge- 
omys the sulcus on the inner side is commonly decidedly iiosterior to 
the plane of the outer sulcus. In Macrogeomys the anterior prism is 
broadly elliptical, and the posterior is elongated antero-posteriorly. In 
Maci'ogeomys heterodus the posterior lobe or heel is very long and slopes 
obliquely outward; the inner face of the tooth as a whole is unnsually 
flat (fig. 27^). 

In Zygogeomys the last upper molar is an imperfect double prism, the 
depression on the inner side being slight, while that on the outer side 
is much deeper. The crown as a whole is longer than broad, and the 
posterior loop or heel ends in a broad lip-like extension not protected 
by enamel and hence subject to change of shape by wear (see fig. 27^), 


[NO. 8. 

Fig. 30.— Types of enamel 
pattern of ujiper premolar. 

(1) Cratofjeomys inerriami,- 

(2) Heterogeomys hispidus; (a) 
anterior enamel biind; (6) lat- 
eral band ; (c) posterior band. 


After the enamel cap of tlie newly born young lias been ground down 
far enough to expose the u^jper ends of the cement bands, the arrange- 
ment of the enamel remains the same throughout the life of the indi- 
vidual and affords excellent generic and in some cases specific char- 
acters. The enamel never envelops the prism in a continuous sheet, 
but is deposited in the form of vertical plates or bands which always 
alternate with bands of cement. These bands are disposed in a definite 
manner on each tooth of the series. In the under ja-w the number in 
each tooth is the same throughout the group; in the upper jaw the 
number varies in the several genera. 

Premolars. — The ijermanent upper premolar has three enamel plates 
(one anterior and one lateral on each side* ) in the genera Geomys 
_ proper, Pappogeomys, Gratogeomys, and Platy- 

geoniys — the posterior being altogether absent 
(fig. 30'). In Zygogeomys, Heterogeomys, Macro- 
geomys, and Orthogeomys the number is in- 
creased to four by the addition of a posterior 
plate, which, however, 
never covers more than 
half of the posterior face 
of the posterior prism, and 
is always restricted to the 
inner or lingual side (fig. 30'^ c). In Orthogeomys 
the posterior plate is sometimes obsolete. The per- 
manent lower x^remolar always has four enamel 
j)lates, the posterior being invariably present and 
covering the whole hinder face of the tooth (fig. "25, 
b, and fig. 32). 

First and second upper molars. — In the first and 
second upper molars, which are simple elliptical 
prisms, the normal number of enamel plates is two, 
one covering the anterior, the other the posterior 
face of the tooth, with a narrow interval filled 
with cement at each end between them (fig. 31^). 
In many species, however, the posterior plate is 
obsolete (fig, 31'). It is present and covers the 
whole hinder side of the tooth in Geomys, Pappo- 
geo-inys, Macrogeomys, Heterogeomys, and Orthogeo. 
mys. It is present but restricted to the inner or 
lingual half of the tooth in Zygogeomys (fig. 31^), 
and is altogether absent in Gratogeomys (fig. 31'^) and Platy geomys. 

*Iii both upper aud lower premolars the anterior enamel plate is convex forward; 
the lateral are strongly bent, couforming to the sulcus between the prisms and 
extending from the convexity of one to that of the other. The resulting shape in 
transverse section is usually like that of the letter IJ, with the opening du'ected out- 
ward aud the base resting on the median line of the tooth. 

Pig. 31. — Types of enamel 
pattern of upper niolari- 
form series in the diti'ereut 
groups : 

1 . Geomys bursarius. 

2. Ciatogeomys caistanoi)>s. 

3. Zygogeomys trichojnis. 

4. Macrogeomys cherriei. 

5. Thomomys bidbivorus. 


Last upper molar. — Throughout the Geomydiw, except in Thomomys, 
the last upper molar has three enamel plates — one anterior, one on the 
inner side, and one on the outer side, with interspaces (cement bands) of 
varyiug- breadth between (fig. 27). In Orthoycomys scalops the outer 
plate is normally divided (tig. 62). The 
anterior plate always covers the whole 
front face of the tooth, and is the same 
in all species ; the two others vary in 
length and shape, and furnish excel- 
lent characters. In Thomomys there 
are but two plates, an anterior and a i 
posterior (fig. 31^). 

Lower molars. — Except in Thomomys, 

the lower ]-0larS have each but a sin- ^'«- 32 -Crowns of lower molariform 

series : (a) Geomys bur.mrius; (6) Thomomys 
gle enamel plate; it completely covers hulUvorus. Except in Thomomys (D the 
the posterior ftice of the tooth, the «^°a™«^^ pattern is the same tLroughout the 
, ■ n 1 • 1 1, • 1 family (as in a). 

anterior face and sides being covered 

with cement (tig. 32, a). In Thomomys each lower molar has two enamel 

plates, an anterior and a posterior (fig. 32, h). 


The foregoing study of the enamel plates shows that all of the 37 
species and subspecies herein described, and all the species of Th6md- 
mys,may be arranged in five principal groups, according to the i)resence, 
absence, or relations of the posterior enamel plate in tlie upper molari- 
form series, as follows: 

1. Posterior enamel plate absent in pm and present in m^ and m- Geomys, 

Pappoocomys, Orthoueomya. * 

2. Absent iu both 2)m and m' and m- Crutoyeomys, Flatygeomys. 

3. Present on inner (lingual) side in both jj?)t and m' and m- Zyyogeomys. 

i. Present on inner (lingual) side in jrm and complete in m' and m^ Hetero- 

geomys, Macrogeomys, Orthogeomys. * 
5. Present in pm and m', m-, and m* Thomomys. 


The number of enamel plates actually present in the different teeth 
has been shown to vary from one to four. The number on each tooth 
has been found constant in the lower series; inconstant in the upper 
series. The lower premolar (which is a complete double prism) invari- 
ably has four, and the lower molars one each, except in Thomomys iu 
which they have two (fig. 32). The upper premolar (a complete double 
prism) has four in some genera ; three in others. The upper interme- 
diary or elliptical molars (m^ and m^) have two in some genera; one in 

*Orthogeomy>i is losing the posterior enamel plate of the upper premolar. It is 
present in 0, latifrons, but greatly reduced or altogether absent in nelsoni and 


others. The last upper molar (an incomplete double prism) invariably 
has two in Thomomys and three in all the other genera. These facts 
indicate that the normal number of enamel ])lates in simple elliptical 
prisms is two, and that one has been suppressed iu all of the elliptical 
molars having only one (the lower molars in all except Thomomys aud 
the first and second upper in Platyc/eomys aud Gratogeomys)^ and in the 
^PP^r premolar when it has only three plates (as iu Platygeomys, Crato- 
geomys, Pappogeomys^ and Geomys proper). This view is sujjported by 
a study of the mechanics of the grinding process. (See pp. 90-97, 


Throughout the family, except in Thomomys, the last upper molar is 
strengthened by three vertical plates or bands of enamel, alternating 
with three interspaces filled with cement (figs. 33, 31). The anterior 
of the three enamel plates is constant in form and relations; the two 
others inconstant. The anterior invariably covers the whole front face 
of the tooth and is convex forward (the convexity may be slight or 
great). The others vary in position, shaj)e, and relative breadth. In a 
single species, Orthogeomys scalops, the outer plate is normally divided 
(tig. 62). In the simplest forms, in which the tooth is a subcylindric 
or subtriangular prism, as in texensis, breviceps, and allied si)ecies (fig. 
33), they are simple vertical bauds of enamel, subequal in size, one on 

Fig. 33. — Variations in form of crown and enamel pattern of m^in restricted genus Geomys. 

1, 2. Geomys tuza. G. Geomys personatus. 

3. tuza /I arid anus. 7 — 10. texensis. 

4. mobilensis. 11 — 13. breiriceps. 

5. arenarius. 

either side of the tooth posteriorly, separated from one another and 
from the anterior enamel plate by similar vertical plates or bands of 
cement. The genus Geomys proper presents no variations from this 
type except in the relative breadth of the inner (lingual) and outer 
(buccal) enamel bands. The inner is more constant than the outer and 
is commonly somewhat broader.* Sometimes the two tend to define a 
lip posteriorly (fig. 33^" and '^). Marked departures from this simple 
type occur in those species iu which the last upper molar is a double 
instead of a single prism ; and since various intermediate conditions in 

*In G. tuza the outer plate is much narrower or shorter than the inner. Since the 
teeth are commonly looked at endwise from above, the enamel pattern is ordinarily 
seen in transverse section, and the three enamel i)lates ap]iear as narrow bands on 
the periphery of the prism. Their breadth on the sides of the tooth i.s shown iu the 
lenfjth of the baud as it appears on the crown. In describing the patteru. therefore, 
it is convenient to use the term length instead of breadth to designate the rel?itive 
width of the vertical enamel plates. 


JAN., 1895.] 



tlic evolution of the double ])iisiu are preseuted by living- species, so 
the several stages in the adaptation of the lateral enamel plates to the 
development of a posterior loop or heel are clearly shown. These 
changes consist in a lengthening or shortening of the enamel plate (as 
it appears on the crown of the tooth) and in the development of a bend 
or flexure by virtue of which the enamel conforms to the curvature of 
the anterior and posterior loops, resulting from the development of a 
dee]) sulcus on one or both sides of the tooth in those species that have 
a double prism. And since the sulcus on the outer side appears flrst 
and is always deepest, it follows that the outer enamel plate is the one 
most affected and shows the greatest range of variation (fig. 34). 

Outer {buccal) enamel plate. — The first step in the formation of a dis- 
tinct and permanent flexure may be seen in Pappogeomys bulleri (fig. 
34,'), in which species the anterior end of the outer enamel plate bends 

Fig. 34.— Forms of crowu aud enanifl pattt-rii of m^ iu the genera in whicli this tooth is a double 

1. Pappogeomys bxtUeri. 8, 9. Orthogeomys nelsoni. 

2. Platjigeomys gijnimirus. 8. Totontepec ; 9. Comaltepec. 

3. Cratogeomyty estor. 10. Heterogeomyshispidus. 

4. oreocetes. 11. torridus. 

5. peregrinus. 12. Macrogeomys cherriei. 

6. Zygogeomys trichopus. 13. contaricensis. 

7. Orthogeomys latifrons. 14. dolichocephalus. 

15. Alacrogeomys heterodus. 

outward in front of the vertical sulcus that marks the outer side of 
the tooth. A slightly more accentuated condition is found in Platy- 
geomys gymnurus (fig.34,-). The extreme development of this flexure 
is attained in the genera Heterogeomys (fig. 34, '" and ''), Macrogeomys 
(fig. 34, '^, '^,i'^), and Orthogeomys (fig. 34, " and **), iu all of which the 
bend is essentially a right angle — a result of the deepening of the 
sulcus between the prisms. At the same time the posterior arm of the 
enamel plate is considerably lengthened in order to protect the elon- 
gated posterior lobe or heel to which it conforms. In Orthogeomys and 
all the known species of Reterogeomys and Macrogeomys the posterior 
limb is about double the length of the anterior; and except in M. 
heterodus it actually reaches the hinder border of the tooth. In Ortho- 
geomys scalops a very remarkable condition i)re vails; the outer enamel 
plate is normally divided (fig. 62). 
7433— Fo!! 8 



[NO. 8. 

Ill riaiiigcomyH the outer enamel baiul is iiornially either straight or 
bent outward at the extreme anterior end — not U shaped as in Crato- 
geomys proper. 

In the remaining groups a widely dilt'erent condition obtains: The 
outer enamel plate is much reduced, and as a rule the two arms are sub- 
equal. This type prevails in Cratogeomys proper and in Zygogeomys — 
groups whose interrelations are distant and obscure. In Crato- 
geomys the outer plate is normally ( ?) reduced to a mere angle or 
U-shai^ed piece at the bottom of the sulcus that gives the outer side 

of the tooth the semblance to a dou- 
ble prism (tig. 35, •'" and ''), leaving a 
wide unprotected interval (cement 
band) on each side. It is variable, 
however, and in some specimens the 
posterior arm reaches nearly to the 
end of the heel (fig. 35, ^). The dif- 
ference maybe sexual; but owing 
to the difficulty in determining the 
sex in these animals, which difflculty 
is greatly increased in the case of 
the young, it is unsafe to place 
much reliance ou the sex marks 
accompanying the specimens. Still 
there is reason for suspecting that 
those specimens in which the outer plate is elongated x)osterioiiy are 
females. The variation is much greater in some species than in others. 
It is most extreme iu C, castanopi^ (fig 29), and least, so far as our 
material goes, iu G. perotensis and estor. In advanced age it some- 
times happens that the lateral enamel bands become abnormally short 
on one or both sides and very rarely become divided in the middle. 
Accidents of this sort are probably the result of shrinkage or atrophy 
of the enamel organ. 

Iu the genus Zygogeomys the outer angle is more open and the enamel 
plate covers about half of the outer side of the tooth. 

The outer enamel plate is slightly longer than the inner in Platy- 
geomys^ and much longer in Heterogeomys, Orthogeomys, and Macro- 
geomys (except in M. heterodus); it is subequal or shorter in all the 
other known forms. 

Inner [Ungual) enamel plate. — The inner plate is much less variable 
than the outer, as jn-eviously stated. It is straight or slightly convex, 
except in the few species that have a real sulcus on the inner side, con- 
verting the tooth into a complete double prism. In these its anterior 
part curves or bends outward. This condition is known in the three 
genera, Heterogeomys., MaerogeomySj and Orthogeomys. In Heterogeomys 
the outward curvature is slight (fig. 34, ^" and i^); in Macrogeomys cJoli- 
eliocephalus and Orthogeomys latifrons it is strong (fig. 34, i* and'). In 

Pig. 35.— Variations in form of crown and 
enamel pattern of ni^ in Platygeomyg and in 
Cratogeomys merriami. 

1, 2. Flatygeomys gymnurus. 

3. Flatygeomys tylorhinus. 

4. Flatygeomys ftimosus. 

5-8. Cratogeomys merriami (all from Ameca- 
meca, Mexico). 


leiigtli and position the inner plate is much more variable: It reaches 
the hinder end of the toDth in Geomys proper, Gratogeomys, Pap^wgeomys, 
Flatygcomi/s* Zygogeoinys, and OrfJiogeomys; falls slightly short of the 
end in Macrogeomys, and very considerably short in Ileterogeomys. In 
Heterogeomys it barely covers half of the inner side of the tocth; in all 
the other known species it covers nearly two-thirds or more than two- 
thirds of the inner side. The condition in Ileterogeomys therefore is 
clearly exceptional. 


Specimens of pocket gophers young enough to show the deciduous 
premolars and the unworn crowns of some of the molars are so exceed- 
ingly rare that I have seen but four in the entire series of specimens 
of this genus examined in the preparation of the present paper. Two 
of these are Geomys bursarius from Elk River, Minn., collected by Ver- 
non Bailey April 29, 1888, and May 14, 188G (Xos. 4909 and 2927, Mer- 
riam collection); f he third is a young Geomys mohilensis from Milton, 
Florida. The fourth is a juvenile specimen of Heterogeomys torridus 
from Motzorongo, Mexico, collected by E. W. Nelson March 5, 1894 
(No. 03043, IJ. S. :N^. M.). The unworn teeth are so much alike in the 
two genera that they may be described together. 

Incisors. — In both genera the grooves in the front face of the upper 
incisors are very much deeper and larger than iu the adult, and the 
convexities are much more strongly rounded. In the young of Geomys 
hursarius the two grooves do not present the dispro[»ortion character- 
istic of the adults, the small inner groove being relatively much deeper 
and larger, though by no means so large as the median groove. 

Deciduous premolars. — The crown of 
the upper deciduous premolar is much 
elongated and has an anterior prism in 

addition to the double prism of the per- t,T>in--/y/. | |\| l)\\f-\""~^3 
manent tooth (pi. TO, figs. 1 and 3). The 
double prisms are united on tiie inner '^ r^ 

(lingual) side, forminga U-shaped grind- fig. se.-Lower moiariform teeth of a 

iug surface (with the opening directed "•'^^'S' yo«ng Geomys bunanus, showing 

. „ ]\-j? j.j?i-i j_ii ileciduovis and permauent premohir in 

outward) m front of which, separated by ,i,„^ ,,,^ nn worn crown of m , which has 

sulcus, is the small transversely elongated not yet reached tlie plane of the crowns 

summit of the anterior prism. ^ The crown °' *''" "''^''' '"'"'• 
of the lower deciduous premolar is likewise much elongated, and it is 
irregularly and incompletely divided into three lobes (pi. 10, figs. 2 and 
4&). Both upper and lower premolars have the anterior and posterior 
roots far apart, and the permanent premolar may be seen between them 
(fig. 30, and pi. 10, figs. 1-4, a). 

*In Platygeomys fumosus the inner enamel band seems to be normally shorter than 
the outer, and only half or less than half the length of the anterior band (fig. 35^). 




[NO. 8. 

Permanent premolars. — One of the upi^er deciduous premolars (pi. 
16, fig. 1 h) has been removed from the baby skull of Heterogeomys tor- 
ridiis, exposing the unworn crown of the permanent premolar (pi. 10, 
fig. l.r). The permanent j)remolar also has been removed and figured 
in several positions to show the form, size, and relations of its primi- 
tive enamel cap (pi. 16, figs. 5, 6, and 7). For ready comparison, the 
corresponding tooth in an adult of the same species has been figured 
also (pi. 16, fig. 12). On reference to pi. 16 it will be seen not only 
that the crown of the young premolar is completely enveloped with 
enamel, but that the enamel cap reaches down over the shaft of the 
double prism, covering nearly half of the tooth (figs. 5, 6, and 7) and 
passing continuously into the four enamel bands that alone remain in 
the adult (fig. 12*). The fact that the young of the various species as 
usually obtained rarely show any trace of the enamel cap indicates 
that the growth of the young teeth and grinding down of the crowns 
progress with surprising rapidity. A very young Cratogeomys casta 
7iops from Las Animas, Colo., collected by Dr. A. K. Fisher, has only a 
remnant of the enamel cap left (i)l. 16, fig. 14). 

The unworn crown of the upper premolar (pi. 16, figs. 1 a', 5, 6, 7) has 
a single transverse crest on the anterior prism, an incompletely double 
transverse crest on the posterior prisni, and an oblique ridge connect- 
ing the two on the inner side. The single crest of the anterior prism 
is notched or bifid at the apex, and has a small upright lobule at the 

base of the notch on the inner side. 
The double crest of the posterior prism 
is open on the outer side, and the crest 
as a whole is roughly and narrowly 
U-shaped. The summit of the anterior 
crest is bilobate; that of each arm of 
the posterior crest is irregularly tri- 
lobate or trituberculate. . fl 
••-! ; I ■" s - >* The enamel cap of the permanent 

lower premolar is a complete double 
prism, each moiety of which bears an 
independent transversely elongated 
crest (fig. 37). The summit of the an- 
terior crest (fig. 37-), is trituberculate; 
that of the posterior is incompletely 
double, being split lengthwise into two 
unequal parts, the posterior of which is 
the shorter and more irregular. The trituberculate crest of the anterior 
prism is bilaterally symmetrical. There are two large tubercles or lobes, 
one on each side, and a smaller median one, which is much elongated 
antero-posteriorly and is continuous ■oith the ridge connecting the 
anterior and posterior prisms. 

*In figs. 5, 6, 7, and 12 the cement bands are shaded, thus serving to hringout 
the enamel more distinctly. 


Fig. 37. — Right lowenin worn permanent 
premolar of Heteroijeomi/s torridus: (1) 
inner or lingual side ; (2) enamel cap from 
above; c, cement bands; e, enamel; eo, 
enamel organ. 

JAN., 1895. 



e -- 

c -- 

Molars. — In all of tlie young skulls under consideration the decidu- 
ous premolar and the intermediary molars (m 1 and U) have been 
used, and their enamel caps have been partly ground down, while the 
permanent premolars and last molars have not yet sutiered attrition. 
The premolar has been already described. The enamel cap of the last 
hirer molar, which has not yet reached the plane of the crowns of the 
other teeth (lig. 38 and pi. 16, tigs. 2, f7, 4, ^Z, and 9, d), 
presents two complete transverse crests, each of 
which has an undulating summit incompletely 
divided into three lobes. The two crests are sepa- 
rated by a deep furrow and show no tendency to 
come together at any point. The enamel cap covers 
a little more than half of the tooth (fig. 38, e). The 
last upper molar (pi. 10, figs. 1, c and 3, c) has just 
reached the level of the other teeth. Its unworn 
crown in both genera presents a well-defined anterior 
and a less distinctly defined po.sterior crest, sepa- 
rated by an interspace which is bridged over by an 
oblique enamel ridge on the inner side of the median 
line. The anterior crest is incompletely trilobate. 
The posterior crest is thickened and less symmetrical 
than the anterior, and in Heterogeomys torridus (pi. 
10, fig. 1, c) it is incompletely double, being partly 
divided by a transverse excavation. 

The crowns of the first and second upper molars present different 
degrees of wear in the three young specimens at hand, and none of 
them are young enough to show the transverse crests by which they 
were undoubtedly crowned before the tops of their enamel caps were 
ground down. The wearing, however, has not progressed so far as to 
obliterate the double crowns characteristic of immaturity except in the 
upper molars of one specimen of G. bursarius (I^o. 4009). In the other 
skull of this species (jSTo. 2927) a transversely elongated loop of enamel 
incompletely divides the grinding surface of m'\ indicating the former 
presence of two transverse loops, as in the lower molars. In the lower 
series the double crowns are well shown in both Geomys bursarius (pi. 
16, fig. 4) and Heterogeomys torridus (pi. 16, fig. 2). In one skull of 
Geomys bursarius (pi. 16, fig. 4) the second lower molar is only slightly 
worn, and its crown presents two transverse loops separated by a 
decided depression. In the other skull it is more worn, but still is incom- 
pletely divided. The crown of the first lower molar in both skulls is 
deeply notched on the inner side and slightly on the outer, showing that 
when unworn it resembled the others. 

i^ummary.— The summits of the unworn molariform teeth in Geomys 
and allied genera are not only completely covered with enamel, but the 
enamel cap is complicated by crests and tubercles. The permanent 
premolar, which is a double i)rism, has a single transverse crest over 

- eo 

Fig. 38.— Right last 
lower molar of very 
yonng Heterogeomys tor- 
ridus (from game speci, 
men as fig. 37) ; inner or 
lingual side, showing 
unworn enamel cap, and 
relations of enamel and 
dentine lower down : c- 
cement bands ; e, enamel ; 
eo, enamel organ. 


the anterior prism and a partly double crest over the posterior. The 
true molars are bilophodont, each carrying two transverse crests. In 
the case of the last upper molar, the i)osterior crest is thickened and 
somewhat irregular and may represent the coalescence of two crests. 
It is joined to the anterior by an oblique ridge on the inner side. In 
the premolar and last molar, above and below, the summit of each crest 
is more or less distinctly divided into two or three lobes or tubercles. 
There is every reason to believe that the crowns of the intermediary 
molars (m ' and ') are similarly crested-tuberculate when in the unworn 
condition, but in the specimens at hand their summits are worn down 
too far to show it. 

The crowns of the unworn teeth are bilophodont in all the lower 
molars and in the first and second upper molars. The premolar and 
last upper molar (m^) may be considered as imperfectly trilophodont, 
the posterior prism in each instance being incompletely double. 

The theory that permanently rootless teeth with flat griiiding crowns 
are more primitive and less specialized than rooted teeth with tubercu- 
late crowns receives a decided setback in the circumstance that the 
young unworn molars in the Geomyiilw are provided with crested-tuber- 
culate enamel caps, and that the adult teeth, though simple when con- 
sidered singly as individual prisms, constitute, when taken collectively, 
one of the most highly specialized grinding and cutting machines thus 


As already stated, the bilophodont crowns of the embryo and very 
young molars are hardly ever seen, the wearing down of the primitive 
enamel cap proceeding so rapidly that the youngest specimens ordina- 
rily coming under the eye of the naturalist have flat grinding surfaces as 
in the mature animal. During the reduction of the young crown four 
different types of enamel i)attern, represeutingas many stages of wear, 
succeed one another as follows: 

First stage (before the crests are completely obliterated) : iico parallel 
disconnected transverse loops. 

Second stage (when the sulcus between the crests is reached): a 
figure 8. 

Third stage (after the sulcus is passed and before the tops of the 
cement bands are reached) : a continuous ring or circle. 

Fourth stage (after the tops of the cement bands are reached): the 
pattern of the mature tooth, consisting of from one to three bands of 
enamel alternating with the same number of bauds of cement, as already 
explained in detail. 

The first stage is of brief duration ; the second still more evanescent; 
the third decidedly longer than the first and second together; the fourth 
continues throughout the life of the animal. 



During the-eaiiy part of the fourth stage the form of the shaft of the 
tooth changes, the double prism characteristic of -extreme youth giving 
place to the single elliptical prism of the adult (except in the last upper 
molar, which in some genera remains permanently double). It seems 
remarkable that a tooth having a large double crown like the first and 
second lower molars of the very young animal (pi. IG, figs. 2 and 4) 
should be capable of changing its form to that of the single transverse 
ellipse of the adult (pi. 10, fig. 17) in a very brief period and without 
molting the tooth. That it does so is not open to question, and may 
be demonstrated by making a section of the lower part of the young 
touth. This has been done in the case of the second lower molar, as 
shown in pi. 16, fig. 4, where 4c.x is a transverse section of the same 
tooth from the lower fourth. 'The antero-posterior diameter of the 
tooth decreases from above downward and the vertical groove on each 
side becomes shallower and shallower and finally disappears. The 
change in the shape of the crown takes place naturally by the rapid 
wearing down of the grinding surface, which brings successively lower 
parts to the top. 


Throughout the group the enamel organ is situated at the base of the 
teeth, as usual in rodents having prismatic molars. In the young tooth 
the enamel organ is very much larger than in the adult, owing doubt- 
less to the greater rapidity of growth in early life. Thus on referring 
to pi. 10 (figs. 5, 0, and 7) it will be seen that the enamel organ occupies 
about one- fifth of the length of the upper premolar in a very young 
animal, while in the-correspouding tooth of an adult of the same species 
(fig. 12) it occupies only about one-fifteenth of the length of the tooth. In 
extreme age partial atropliy of the enamel organ sometimes takes place, 
causing a shortening of the enamel on that side. In a few instances an 
enamel plate has been found divided in the middle, due doubtless to 
atrophy or injury of the enamel organ in the same vertical plane. 


A core of osteodentine traverses the central jiart of each tooth. In 
the premolars and all of the molars except m^ it forms a large elliptical 
shaft in the middle of each prism. In m^, whether single or double, the 
osteodentine is a single core, conforming in shape to the shape of the 
tooth. On all sides it passes into the true dentine, by which it is com- 
pletely enveloped except at the free ends. At the lower end it passes 
insensibly into the growing pulp. In other words, the osteodentine is 
a central core consisting of the hardening pulp .and containing the 
vessels by means of which the tooth is nourished. In the Geomyidct' it 
forms a considerable part of the substance of the tooth, as usual in pris- 
matic teeth growing from persistent pulps. In the genera Geomys and 
Cratogeomys it is pale bufty or yellowish brown in color, and conse- 


quently not conspicuous. In the genera Heterogeomys and Zygogeomys 
it is dark brown, in striking contrast to the white of the rest of the 



The individual teeth have been described. It remains to consider 
them as parts of a complex and highly specialized mechanism for cut- 
ting and slicing the food, to describe the muscles that operate the 
machine, to mention other structures concerned in the act of mastica- 
tion, and to show how a bit of root or other hard vegetable tissue is 
cut loose, sliced, and reduced to puli> ready to pass into the stomach. 

The primary object of the dental armature is twofold: (1) To enable 
the animal to bite or chisel off" pieces of the hard vegetable substances 
on which it feeds, and (2) to reduce these pieces to a condition of 
minute subdivision suitable to be tuined over to the stomach for 
digestion. The. incisors serve the additional jHirpose of bars, axes, and 
picks in helping the animal overcome the various obstacles encoun- 
tered in driving its tunnels through different soils. When the front 
teeth are used for this purpose, the resulting dirt and chips are kept 
out of the mouth x^roper- by a furry partition, elsewhere described, 
which divides the mouth- as a whole into two chambers. 


The- way the teeth are fastened in their sockets is in harmony with 
the other remarkable adaptations of the grinding apparatus. The 
attachment is effected by means of the periosteum of the alveolus, 
which does not invest the teeth, but is firmly adherent to the cement 
bands, leaving' the enamel faces free. Thus each tooth is suspended 
by one or more vertical cushions, which extend all the way from root 
to gum. This method of attachment not only relieves the tender pulp 
at the base of the tooth from pressure, but gives to the cutting edge 
or edges an elasticity that must be highly effective. In the case of 
the incisors, the area of attachment is very extensive, comprising the 
whole of the tooth below the gum except the enamel face. The lower 
molars throughout the entire group, and the intermediary uj)per 
molars in the genus Cratoffcomys, are attached in the same way on one 
side only — the side opposite to the enamel ov cutting edge. In the 
case of the upper premolars the principal attachment is along the 
posterior face of the posterior prism, while a supplementary band on 
eacli side of the anterior prism serves to keep the cutting edges always 
in place. In those species in which the posterior prism of the upper 
premolar develops an enamel band on its inner or lingual side, the 
tooth is suspended by four cement bands. The lower premolar is 
attached by four narrow lateral bands. The»last upi^er molar is inva- 
riably held firmly in place by three cement bands, one on each side 
anteriorly and one on or near the median line behind. 



The upper incisor has been shown to curve in the arc of a circle, to 
cover a little more than a complete semicircle, and to lie in a single 
plane (figs. 18 and 19). Its root is very long with relation to the length 
of the muzzle, always overreaching the first upper molar. It is 
implanted in such manner that its cutting edge is directed downward 
and slightly backward. The hiwer incisor has been shown to curve 
outward in an incomplete spiral, and to traverse the entire length of 
the mandible — its root projecting on the outer side of the condylar proc- 
ess, where it is incased in a thin capsule of bone. This small capsule 
contains the pulp from which the tooth continually grows to replace 
the wear at the other end. The extreme development of these teeth is 
proportionate, of course, to the strain put u^jon them in chiseling hard 
roots. The upper incisor is subjected to less strain than the lower, and 
its principal function seems to be to anchor the cutting machine to the 
substance operated on, while the greatly elongated lower incisor does 
most of the work. The free end of the lower incisor slopes forward 
and upward, its angle of implantation being difierent from that of the 
upper. Tims, while the upper incisor remains stationary, its recurved 
and usually divided tip enabling it to hold fast to the object to be cut, 
the lower incisor plays rapidly back and forth like a steam drill, its 
straight enamel edge doing the cutting. 

The great length of the incisors within the alveolus is necessary in 
order to counterbalance the length of the part that protrudes beyond 
the jaws, and also to afford a large surface for attachment within the 
alveolus so as to relieve the growing root from pressure. The way the 
teeth are attached to the jaw by a long belt or cushion, which envelops 
all but the enamel ftice, gives to the cutting edge an elasticity that 
must be of great service, not only in increasing the efficiency of the act 
of chiseling, but also in relieving the tooth from jar. 

It remains to notice the interesting secondary modifications of the 
skull and molariform teeth, by means of which the animal is enabled to 
open the front part of the mouth wide enough to use the incisors to 
advantage. The molariform teeth stand much higher out of the jaw 
anteriorly than posteriorly, and their roots increase in length propor- 
tionally (fig. 18). The premolars, both above and below, protrude 
twice or more than twice as far as the last molars. Thus, when the 
mouth is shut and the teeth pressed firmly together, the jaws are at 
least twice as far apart at the anterior as at the posterior end of the 
molar series. N"ow, the.distance from the crown of the premolar to the 
putting edge of the upper incisor is two and one-half to three times the 
length of the molariform series on the crowns, and the axis of the skull 
is nearly parallel to the plane of the crowns of the molar teeth. Hence, 
without any other help and with the mouth shut, the ends of the jaws 
(where the incisors cut the gums) would be from five to six times fur- 



[NO. 8. 

ther apart than at the plane of the posterior molars.* This arrange- 
ment permits the necessary i^rotrusion of the jncisors, the cutting 
edges of ^vhich, as a rule, reach the plane of the crowns of the molars 
in the upper jaw and slightly pass this plane in the lower jaw. The 
great advantage of this arrangement is most apparent during the act 
of biting off hard roots, when a very slight opening of the mouth proper, 
entailing only a slight separation of the molars, is sufiBcient (multiplied 
along the length of the strongly divaricating jaws) to separate the 
chisel ends of the incisors widely, enabling them to grasp objects of 
comparatively large size. 


(a) Planner of implantation and curvatures. 

The angle of implantation of the molar series as a whole in both 
upper and lower jaws is peculiar. A transverse section of the skull 
(fig. 39) shows that the roots of the upper molars are nearer the median 
line than the crowns.! It follows that the upper tooth rows are strongly 
divergent from root to crown (fig. 39, e). In the lower series the con- 
Terse occurs, the tooth rows converging from root to crown (fig. 39,/). 
The upper molars slope strongly and curve moderately outward from 
root to crown, while the lower molars both slope and curve strongly 
outward from crown to root. 

The crowns of the opposing series do not meet in a horizontal plane, 
^ but are obliquely truncated: the 

upper series face obliquely doivn- 
tvard and outward; the lower series 
obliquely upward and inward (fig. 
39). When the jaws are shut, lateral 
movement in a horizontal plane is 
impossible. If a circle is drawn 
around the upper molars (fig. 40) it 
is at once apparent that during the 
lateral movement of the mandible 
the crowns of the teeth move side- 
ways in the arc of a circle, thus giv- 
ing the utmost possible mechanical 
advantage. The axis of rotation is 
in or near the basicranial axis, and 
the axis or arc of oscillation is short, 
as in a pendulum. To enable the teeth to withstand the great pressure 
to which they are thus subjected, they have developed very Ion >■ roots 

*The actual condition is not exactly as here described. In the case of the lower 
jaw the distance is decreased by the upward curvature of the anterior end of the jaw 
and the shortening of the diastema. lu the upper jaw it is increased by the excava- 
tion of the under side of the rostrum between the molars and incisors. 

t The roots of the upper premolars are even nearer together than those of the molars ; 
they are, in fact, almost in contact. 

Fig. 39. — Transverse section of skull of 
Platygeomys gi/mmirus, showing manner of 
implantation and relations of niolariform teeth- 
a, Frontal; &, zygoma; c, palate; d, mandible; 
e, upper molar ; /, lower molar ; g, incisor. 

JAN.. 1895.] 



Fig. 40.— Upper and lower 
molars of Flatygeomys gym- 
7iurus in normal position, 
showingangle of truncation 
of crowns, necessitating 
lateral movement in arc of 

and a system of complex curvatures and oblique implantations, and 
uie suspended in their sockets by vertical bands of periosteum, as 
already described. When the jaws are shut, the molars on each side 
curve outward so strongly that the distance be 
tween them below (between roots of lower series) 
is several times greater than above (between roots 
of upper series). The result of this arrangement 
is that the molar teeth, during the lateral move- 
ment of the act of grinding the food, press upon 
the opposing series not only iu such manner as to 
secure the greatest mechanical advantage, but 
also so as to produce the least jar, since the press- 
ure in both directions is distributed over arcs of 
circles. But this is not all, for if the tooth rows 
are viewed from the side another remarkable 
complex of curvatures appears (figs. 18 and 20). 
It is now seen that in addition to the lateral curvatures there are 
strongly developed antero-posterior curves and incomplete spiral 
curves. In the upper series the premolar always slopes strongly 
forward, and the molars curve backward from crown to root. In the 
lower jaw the premolar and intermediary molars (mi and m-z) curve for- 
ward from crown to root and the posterior molar backward. The 
lower premolar is the largest and heaviest tooth of the molariform 
series; it is strongly concave forward, convex backward, and is im- 
planted nearly vertically. The last molar is the smallest tooth, and 
both slopes and curves strongly backward from crown to root. The 
end teeth of each series thus act as braces to support the tooth row as 
a whole during the antero-posterior movement of the jaws in grinding, 
and to keep the molars constantly 'keyed up,' so preventing any tend- 
ency to spacing between the crowns. 

In addition to the curvatures described, 
the molariform teeth are usually more or 
less twisted spirally on their vertical axes, 
so that the two ends lie in different tan- 
gential planes. Furthermore, the outer 
(concave) edge is commonly shorter than 
the inner (convex) edge. 

The molariform teeth are so implanted 
that the roots of each lateral series, above 
and below, lie iu at least two antero- 
posterior planes, the roots of the premolar and last molar in both jaws 
l^eing nearer the median line of the skull than those of the intermedi- 
ary molars. The discrepancy is most marked in the lower series, where 
the posterior lower molars (mj and m.^) actually straddle the root of the 
incisor (fig. 41). The roots of nii and m2 curve down outside (on the 
buccal side) of the incisor, while that of m3 lies on its inner (lingual) 
side. In order to do this the latter tooth (ms) not only curves strongly 


Fig. 41.— Cross section of mandible 
of Plati/geomys (jymnimis, showing how 
roots of nij and ms straddle the incisor. 



[no. 8. 

backward but is twisted on its own axis sufficiently to enable its root 
to lie flatwise against the inner side of the incisor. 

(&) Injiuence of the direction of the jmc movement on the molariform 


The direction of the dominant movement of the jaw exerts a marked 
efl'ect upon the size, curvatures, proportions, and number of enamel 
plates of the molariform teeth. This is well shown in comparing teeth 
from skulls of the same size of Macrogeomys doUchocephalus and 
Platygeomys gymnurus. 

(1) Effect on the size and curvature of the prisms. — The length of the 
molariform series on the crowns is approximately the same in both. 
In M. doUchocephalus, in which the principal movement is antero-pos- 
terior or nearly so, the premolars and last molars, 
which form the end posts of the series, are very 
much lengthened and enlarged, while the inter- 
mediary molars are essentially the same size as 
in P. gymnurus, in which animal the principal 
movement is transverse or obliquely transverse. 
The lower premolar of doUchocephalus (fig. 42, a) 
contrasted with that of gymnurus (fig. 42, b) is 
not only larger and longer, but its root curves 
forward much more strongly, increasing its resist- 
ing power as a brace. Throughout the group 
this tooth (the lower premolar) acts as an immov- 
able post or buttress against which the molars 
l^ress during the to and fro grinding movement; 
hence it is naturally largest in those species in 
which the principal movement is antero-pos- 
terior (see fig, 26).* The intermediary upper molars (m^ and m^) are 
longer and less curved in doUchocephalus than in gymnurus; the inter- 
mediary lower molars (mj and m2) are essentially equal in length in 
the two forms and are equally curved, but the curvatures are differ- 
ent: In M. doUchocephalus the upper half of the prism is nearly 
straight, particularly in m^; the curvatures are more abrupt; the ante- 
rior curve is much greater than in gymnurus, and the spiral twist is 
more pronounced, the root end of the teeth rotating more strongly 
inward. The posterior molar, both above and below, is much broader 
and heavier in doUchocephalus than in gymnurus, and the upper one is 
more strongly curved backward. The strong outward inclination of 
the roots of the end teeth of the series tends to keep the molars per- 
petually keyed up, preventing any spacing between the crowns. The 
destructive effects of the to-and-fro movement of the powerful planing 
machine are thus successfully offset. 

*VVliat the lower premolar accomplishes by its massiveness and fixed position, the 
upper premolar accomplishes by its length and angle of implantation. 

Fig. 42.— Lower premolar 
showing difference in size 
and curvature according to 
whether the domiuaut jaw 
movement is to and fro or 
sideways, a Macrogeomys 
doUchocephalus; h Platy- 
geomys gymnurui. 


(2) Effect on the proportions of the prisms. — The breadth of the molar 
prisms with respect to their anteroposterior diameter is materially 
affected by the direction of the dominant movement of the jaw. This 
is readily seen in the crowns which are much more elongated trans- 
versely in those species in which the principal movement is obliquely 
transverse (P. gymnurus and others) than in those in which it is chiefly 
antero -posterior {M. dolichocephalus and others). In the former series 
the transverse diameter of the crown (of upper molars) averages two 
and one-half times the antero-posterior; in the latter, only two times. 

(3) Eff^ect on the number and size of the enmnel plates. — Perhaps the 
most conspicuous and important of the differences in the molariform 
teeth, resulting from the direction of the dominant movement of the 
jaw, is in the number of the enamel plates on the upper intermediary 
molars. Two plates are invariably present in those forms in which 
the dominant movement is antero-posterior (genera Geomys, Zyyogeomys, 
Orthogeomys, Macrogeomys, and Heterogeomys) ; while only one is present 
in those in which the movement is obliquely transverse (genera Platy- 
geomys and Gratogeomys). In the latter case the enamel is restricted 
to the front face of the tooth, the posterior plate being obsolete, and 
the upper premolar resembles the molars in this respect, the pt»sterior 
enamel plate being invariably absent. 


The arrangement of the enamel plates and the direction of the dom- 
inant movement of the jaw in mastication present two widely different 
types in the animals under consideration. In one of these types the 
principal movement is obliquely transverse; in the other it is antero- 
posterior. They may be best considered separately. 

{a) Dominant movement of jaw obliquely transverse. — When the upper 
tooth row of Platygeomys gymnurus, or any other species in which the 
dominant movement is obliiiuely transverse is 
examined as a whole, it is found to be made up 
of five flattened columns of dentine arranged 
seriatim one in front of another, and each 
faced in front with a vertical plate of enamel 
which projects a short distance beyond the 
crown (fig. 43 '). These five enamel plates are 
strongly convex forward and their curvatures ^.^.o t ■. a ^ 

Fig. 43. — Longitudinal section 

are essentially parallel (fig. 44 ^). An addi- of molariform teeth of piaty. 
tional enamel plate covers the posterior face ^'""''"* i/i/ ''"'«'•«« (cUagram- 

n .. . . .,, „ , , matic). (1) Upper; (2) lower. 

ot the anterior pillar of the premolar and the 

isthmus connecting the two parts of this tooth; and the two lateral 
plates of the last upper molar may be considered as together forming 
another cutting plate, making seven in all in the upper series. Turning 
now to the opposing series — the lower molars — the opposite or 
complementary condition prevails, a curved enamel plate covering 



[no. 8. 

the posterior face of each of the live flattened columns of dentine 
(figs. 43' and 44-). Two additional transverse plates complete the 
armament of the lower premolar, making seven in all, as in the upper 
series. It should be observed further that the concave sides of the five 

regular enamel i)lates face bad-ward in the 
upper series and forward in the lower series. 
If now the two series are superimposed in 
the position they naturally assume in the 
mouth (tig. 45), and the lower series is moved 
obliquely forward and outward in the direc- 
tion it normally takes when drawn by the 
masseter, the two sets of curved enamel 
blades come together like the opposing 
blades of seven pairs of shears working 
almost simultaneously, with this difference 
in favor of the teeth, that in addition to the anteroposterior closing 
movement the curved blades slide over one another laterally, thus giv- 
ing the greatest possible advantage in slicing the hard roots and other 
unyielding substances on which the animals feed. The length of the 
blades gives a long sweep, while the curvature* insures the passage of 

Fig. 44.— Crowns of luolariforni 
teeth of Flatygeomys gymniirns. 
(1) Upper series; (2) lower series. 

Fig. 45. — Superimposed molar series of Platygeomys gymnurus showing relations of enamel blades 
(light outlines lower .series; dark, upper); a front end. 

each particle of food against the cutting edges. The action is still 
further favored by the obli(i[ue truncation of the molar crowns and the 
peculiar method of suspension already described whereby the unyield- 
ing enamel blades gain an elasticity which gives them a shearing motion 
of the highest efficiency. The cutting is done during the obliquely for- 
ward movement of the mandible; the complementary movement is sim- 
l)ly one of recovery and has no effect on the food. 

The forward movement is evidently complex and apparently consists 
of three independent motions by which the mandible is shifted from 
side to side in a zigzag manner, as follows: (1) The mandible is carried 
obliquely forward and to one side until each of the enamel blades has 
completed a shearing cut against one of the blades of the upper series; 
(2) it is then carried obliquely forward in the opposite direction until 
each blade completes another cut; (3) it then turns again and the 
molar blades accomplish a third cut, leaving the upper and lower series 

* The concave sides of the enamel blades move toward aud over one anotlier, 
inclosing the food in a rapidly contracting loop, the opposite sides of which meet 
and pass, leaving no chance for food to escape. 



nearly in the same vertical plane. The lower series has been carried 
forward so that each tooth stands considerably in advance of the 
corresponding- tooth of the upper series. A fourth movement, that of 
recovery, brings the mandible back to the starting point. The limit of 
the to-and-fro movement is nearly the same throughout the family 
Geomyirl(e and is measured by the anteroposterior diameter of the 
crown of the premolar, which it slightly exceeds. When the jaws are 
at rest the front face of the lower premolar rests on or slightly behind 
the corresponding face of the upper j)remolar. When the jaw is drawn 
forward until the lower incisor strikes the posterior beveled face of the 
upi)er incisor, the lower premolar stands free from and wholly anterior 
to the upper. Hence, the thickness of the premolar is slightly less 
than the distance covered in the to-aud-fro movement of the jaw. This 
being the case, it is easy to ascertain the number of cuts made by the 
enamel blades during each stroke of the jaw in mastication. By super- 
imposing tracings of tlie upper and lower molar series (fig. 45) and 
moving the latter oblicpiely forward and outward under the former 
it appears that of the four cutting blades of the lower premolar the 
first is unimportant, the secontl glides over two cutting edges of the 
upper premolar during each stroke, the third and fourth cut against 
three edges each, and the single blade of each of the three true molars 
cuts over three enamel plates of the upper series (counting as one the 
two lateral plates of the last upper molar against which they cut), 
making seventeen cuts for each stroke of the jaw. 

In a tame Geomys lufescens it was found (by actually counting the 
contractions of the temporal muscle) that the mandible makes 200 com- 
plete strokes a minute, which, at the rate of 17 cuts with each stroke, 
is equivalent to 3,400 cuts by a single pair of blades. This is the num- 
ber of cuts made by the blades of a single ramus; but since the blades 
of both sides doubtless act simultaneously the number should be 
doubled, making a total of G,800 cuts each minute! 

The enamel plates are so spaced, by means of slight differences in 
the anteroposterior diameters of the upper and lower molars, that 
when the jaws are shut together and the movement of mastication 
takes place, only one pair of cutting edges comes into bearing at a time. 
The seven sets of blades, therefore, instead of cutting simultaneously, 
follow one another in rapid succession, one pair just completing its 
stroke as the next begins. By means of this delicate adjustment only 
one-seventh the power is required that would be necessary if all oper- 
ated together. 

If, in the animals having the above described shearing movement of 
the molars, a i)osterior enamel plate was present in the upper inter- 
mediary molars, or an anterior plate in the lower molars, the possession 
of such plates would obviously be a raechauical disadvantage, as they 
would not only be of no use but would be actually in the way. Ilence, 
in the evolution of this specialized type one plate has been gupx)ressedj 



[NO. 8. 

Fig. 46. — Longitudinal section of 
molariform teeth of Macrogeomys 
dolichocephalus (diagranmiatic) . 
(1) Upper series; (2) lower. 

and the fact should be emphasized that the loss of a useless enamel 
plate is as clearly a sign of specialization as the development of an addi- 
tional plate where needed. In the less specialized genus Thomomys 
both plates are always present (tig. 32, h). 

{h) Dominant movement of jaw anteroposterior.— In the remaining 
groups the movement of the jaw is chieiiy anteroposterior, the crowns 

of the teeth are more broadly elliptical, and 
enamel plates are i^resent on both sides of the 
upper molars (figs. 46 and 47). In some genera 
Ihe posterior plate, which is always thinner 
than the anterior, covers the whole hinder 
face of the tooth; in others it is restricted 
to the inner side, according to the exact axis 
of jaw movement. Whenever the ellipse is 
broad, and is so directed with reference to the 
enamel plates of the adjacent teeth that it 
presents a free edge toward the food that 
is being ground, this edge is invariably protected by a plate and cutting 
edge of enamel. Conspicuous illustrations of this law may be seen in 

the upper premolar of Zygogeomys, Macrogeo- 
mys, and Heterogeomys, and in the upper inter- 
mediary molars of Zygogeomys, in all of which 
the posterior enamel plate is restricted to the 
lingual side — the side impinged upon by the 
food. On the other hand, non-cutting edges 
protected by the enamel plates of adjacent 
teeth are better off without enamel of their 
own, because such enamel, if present, would 
not only be of no use, but would be actually in the way, as already 

By superimposing tracings of the upper and lower molar series of 
Macrogeomys dolichocephalus (fig. 48) and moving the lower backward 
and forward under the up^jer as nearly as possible in the way they are 
moved by the living animal, it is found that the cutting blades make 
nineteen cuts during each forward stroke of the jaw, as follows: The 

Tig. 47.— Crowns of molariform 
teeth of Macrogeomys dolicho- 
cephalus. (1) Upper; (2) lower. 

Fig. 48.— Superimposed molar series of Macrogeomys dolichocephalus .showing relations of enamel 
blades. Light outlines, lower series; dark, upper, a front end. 

anterior plate of the lower premolar does not cut at all, or, if it cuts its 
action is so limited as to be of no particular consequence; the posterior 
plate of the anterior prism makes two cuts ; the anterior plate of the pos- 
terior prism, three cuts ; the posterior plate of the premolar and that of 


the first molar make four cuts each; the second and third mohirs, three 
cuts each (counting the two lateral plates of the, upper molar, against 
which ma acts, as if they were a single plate), making nineteen in all. 
During the return movement fourteen cuts are made, as follows: The 
second and third transverse plates of the i)remolar make two cuts each ; 
tbe fourth, three; the first molar, three; the second and third molars, two 
each. The backward stroke is evidently less powerful and less effective 
than the forward stroke. 

Since the teeth on both sides of the mandible cut simultaneously, the 
total number of cuts during each complete stroke will be double the 
number above mentioned, or 38 for the forward stroke and 28 for the 
backward stroke. Assuming that the luimber of complete strokes each 
minute is the same as in Geomys luteficens, namely, 200, the total number 
of cuts made each minute on the forward stroke would be 7,600, and on 
the backward stroke 5,(300, making a grand total of 13,200 cuts each 
minute while the jaws are in active operation ! 

Stroke of the jaw. — There being no postglenoid process, the backwaid 
movement of the jaw is not interrupted until the condyle strikes the 
auditory bulla at the base of the tube of the meatus. When the con- 
dyle rests in this position and the molar series are in api)Osition, the 
front faces of the premolars above and below are in line. The forward 
movement of the jaw is stopped by the incisors and reaches its limit 
when the front face of the low^er incisor strikes against the posterior 
face of the beveled edge of the ujiper incisor. When this happens 
the upper premolar usually rests on the back part of the first lower 

From the foregoing account it must be clear tliat the molars, which, 
considered as individual teeth, are simple elliptical tubes, lacking the 
complicated enamel patterns of the beaver, porcupine, and many other 
rodents, are so constructed that collectively they form one of the most 
powerful and highly specialized cutting and slicing machines known. 
The way the narrowly elliptical crowns are placed side by side flatwise, 
the hard projecting enamel blades alternating with surfaces of soft den- 
tine, results in the production of a cutting and rasping apparai us e(iual 
if not superior to that possessed by those rodents and ungulates tliat 
have complicated enamel folds within the substance of the teeth. The 
obli(puty of the crowns, whereby the upper and lower series are brought 
together in the arc of a circle, gives them remarkable power under 
the transverse movement of the jaws, while the way the teeth are stis- 
pended on vertical cushions, together witii the angle of imi)lantati()n 
and the double curvatures of their prisms, enables them to withstand 
the great strain to which they are subjected Mithout danger of dis 
])laeement and without injury to the tender pulps at their bases. 

The secondary modifications of the skull resulting from the action of 
the muscles operating this wonderfully effective machinery are dis- 
cussed elsewhere (pp. 104-107), 
7133— Is^o, 8 7 



Tho cireniiistance that all the iiieinbers of the (icomyhlwYwo, mider- 
grouiid has an important l)earin.t;- on tliekind of food habitually eaten, 
and is thus the remote cause of the special adaptations of the dental 
armature, and of the secondary cranial moditications necessitated 
thereby. The animals sometimes come to the surface and cut the stems 
and leaves of plants, which they draw into their subterrannean tunnels, 
but in the main the choice of food is restricted to such parts of plants 
as nuiy be found within the ground. The food therefore consists chietiy 
of tubers and roots, including the hard roots of trees and shrubs, the 
tough rootstalks of the mescal or agave, and tlie like. In dealing with 
these unyielding substances the aniaial gains one decided advantage — 
the roots on which it feeds are held firmly in place by the earth while 
pieces are chiseled off by the broad, trenchant cutting edges of the 
powerful incisors. In the case of certain relatively soft substances, 
such as j)otatoes, the lower incisors are sometimes used alone, both as 
a i)ry to dislodge pieces and as a scraper to scrape off thin slices, but 
as a rule both upper and lower incisors operate together. The prin- 
cipal function of the upper incisors seems to be to transfix the tuber and 
oppose the action of the lower while the latter do most of the work, 
moving rapidly backward aiul forward (and at the same time upward), 
until a piece of food is cut loose or sufficiently undermined so that it 
may be torn loose by a backward movement of the head while the teeth 
are held firndy together. The bit of food thus dislodged is eitlier 
reduced in size by trimming — during which operation it is held between 
the large Ibrefeet, the long claws turned inward toward one another — or 
is passed directly into the mouth or cheek pouches. The mouth i)roper, 
it should be remembered, is separated from the incisors by a furry parti- 
tion which is directly in front of the molars. This diaithragm-like par- 
tition is of great service to the animal, keeping dirt and chips out of 
the mouth. When the food reaches the mouth ])roper the tongue and 
lips keep it between the teeth, where it undergoes the treatment com- 
monly described as grinding. But in the highly specialized forms of 
the Geonn/idcv no real grinding occurs — the whole process is one of cut- 
ting or slicing. The arrangement of the enamt 1 plates that form the 
blades of the cutting machine has been already described in detail. 
In those species in which the principal movement of the jaw is antero 
posterior the mechanism is essentially a phoiiu;/ machine, wliile in 
those in wliich the dominant movement is obliquely transverse it is a 
shc(tri)u/ or HJicing machine. In either case the tough vegetable fibers 
composing the food are quickly reduced to a pulp, which is promptly 
l)assed on to the stomach for digestion. 


The principal muscles concerned in the movements of the jaw are (1) 
temporal, (2) masseter, (3) internal pterygoid, (4) external pterygoid, 


(o) dig'astric, ami (6) trausverse mandibular. Cf these, by far the most 
important single muscle is the masseter. 

The temporal muscle occupies the whole of the upper surface of the 
cranium behind the orbits, covering the parietal, squamosal, and pos- 
terior part of the frontal as far forward as the postorbital prominence. 
It arises from the flat upper suifacesof these bones and from the larab- 
doid and sagittal crests. The muscle is indistinctly divided into two 
parts — a superficial and a deep — which are m)t well detiued in their 
origin. The fibers of the muscle as a whole converge anteriorly; those 
of the superficial part are inserted into the apex, posterior edge, and 
inner side of the coronoid process; those of the deep part play over the 
trochlear groove and at the margin of the orbit drop vertically down- 
ward and are inserted by a dense aponeurosis on the anterior edge of 
the basal half of the coronoid ramus from the plane of the molar crowns 
upward to a point slightly above the plane of the coronoid notch; pos- 
teriorly the muscle remains fleshy and c(3vers the inner side of the cor 
onoi<l ramus wliere its insertion extends downward to the bottom of 
the deep pit between the ramus and the posterior molar. The function 
of the temporal muscle is to shut the mouth, and in some species to 
draw the mandible slightly backward. Operating in connection with 
the digastric, it performs the backward stroke of the to and fro move- 
ment of the jaw in the (Jolichocephidic series, the masseter producing 
the forward stroke. 

The masseter is a large complex muscle and is by far the most impor- 
tant of the muscles concerned in the act of mastication. It is incom- 
pletely divided into three parts, which, from their principal sources of 
origin, may be described as the rostral or suiierficial, maxillary, and 
zygomatic parts. 

(1) The rostral or superficial part arises by a long an<I dense aponeuro- 
sis from the outer side of the rostrum on tlie line of the preniaxillo- 
maxillary suture, its npper border being immediately in front of the 
infraorbital foramen. It passes thence obliquely downward and back- 
ward, developing muscular fibers and spreading- out posteriorly into a 
flat muscular band which is inserted upon the inferior crest of the 
masseteric fossa and the inferior surface of the mandible from the 
digastric crest posteriorly to the base of the angular process, its inser- 
tion being wholly fleshy. It is the most i>owerful muscle in drawing the 
jaw straight forward, and is aided in the dolichocephalie species by the 
zygomatic branch of the masseter. 

(2) Tlie main body of the masseter arises from the side of the anterior 
part of the maxilla and adjacent parts of the maxillary root of the 
zygoma. Anteriorly it slightly overlaps the posterior part of the pre- 
maxilla immediately below the top of the rostrum, where it forms a 
distinct crest continuous with the anterior edge of the maxillary root 
of the zygoma. The principal origin covers the whole of the anterior 
face of the vertically expanded zygomatic process of the maxilla, and 


in additiou a thin supplenieiitary sheet takes origin from the posl-erior 
face of the same bony plate (withni the orbital chamber). J'osteriorly 
its origin is limited on the outer side by a thick aponeurosis, which is 
firmly attached to the inferior surface of the antero external angle of 
the zygoma. The part within the orbit follows the inner face of the 
korizontal part of the zygoma all the way back to the glenoid ligament, 
to which its posterior libers are attached. This part of the muscle is 
insei ted on the outer side of the neck of the condylar ramus just above 
the incisor capsule. 

(3) The ziif/oniatic part of the masseter arises from the outer side of 
the horizontal partof the zygoma, its origin embracing the outer sur- 
face of the scjuamosal root of the zygoma and the outer side of thejugal 
below the oblique crest which marks the limits of its insertion above 
and in front. It arises also from the aponeurotic septum which sepa- 
rates it from the mam body of the muscle. It is inserted ujion the angu- 
lar process of the mandible, its insertion covering the upper surface of 
this process irom the incisor capsule outwardlj^ to and over the head of 
the process, and also the under surface of the process to its very base, 
where its insertion becomes continuous with that of the main body of the 
muscle. Its function in Geomi/.s i)ioper and in all the (loUchoccphalic 
si)e('ies is to draw the jaw forward. In the phitucepludic species its 
insertion is carried so far outward by the great elongation of the angu- 
lar process that it serves to move the jaw sideways, in which act it is 
aided by the pterygoid muscles. 

'J he internal pferyf/oid mvscle arises from the pterygoid fossa of the 
skull, which it completely tills. Passing directly outward and slightly 
downward, it is inserted into the pterygoid fossa of the jaw, where its 
line of attachment has developed a strong crest along the posterior edge 
of the angular process. Its function in Geomi/s proper and in all of the 
dolichocephalic species seems to be to bring the posterior end of the molar 
series firmly together when the jaw is shut. In the platycephalic species 
it aids the masseter in moving the jaw sideways. 

The external pterygoid arises from the alispheuoid bone on the outer 
side of the root o^ the last upper molar and is inserted into tlie inner side 
of the neck of the condyle. Its function is evidently mainly the same as 
that of the internal pterygoid, though in addition it tends to move the 
mandible slightly forward. 

The digastric arises from the paroccipital process and adjacent parts 
of the mastoid and audita! bulhie, and is inserted on the digastric crest, 
Avhich projects backward from the hinder part of the symphysis of the J 
mandible. It is largely developed, its function being not merely to 
open the mouth, but, operating with the temporal, to draw the jaw 
strongly backAvard in the to and fro movement of mastication in the 
dolichocephalic series. Its action is very direct and powerful. 

The transverse mandibular muscle connects the two halves of the lower 
jaw immediately behind the symphysis, where, in many species, there is 


;i distiuct fossil for its lodgment. It must fulfill an important function 
in regulating tlie adjustment of the tootii rows during mastication. 


1 have not dissected the muscles of the cheek pouches, but they have 
been described by Dr. C. E. McChesney* and Prof. H. L. Osborn.t 
Dr. McChesney states that the aperture of the pouch is surrounded by 
a narrow delicate constrictor muscle, and that the long pouch itself, 
which extends back to the shoulder, is enveloped by a contractor mus- 
cle which seems to be a modified part of the platysma myoides. This 
muscle consists of two parts : (1) a retractor part, reaching from the 
extreme posterior end of the pouch backward over the muscles of the 
back and ending in a broad thin tendon which blends with the tendons 
of the superficial dorsal muscles, to be inserted into the spines of the 
three last lumbar vertebne; (2) an anterior part which envelops the 
pouch proper. This latter is in turn subdivided into two parts — exter- 
nal and internal. The former covers the upper or outer T)ortion of the 
[louch and is inserted into the maxillary bone ( probably j^rcmaxillary). 
The latter covers the inner and under sides of the pouch and is attached 
to the mandible, though the uppermost fibers join those of the former 
division, to be inserted on the upper jaw. Dr. McChesney states that 
the lower and inner surface of the muscle is thickest, the outer surface 
l^eing thin and of little power. 

Prof Osborn describes the muscles of the pouch as follows: "There 
are three distinct sets of muscles; these are, first, a circular muscle that 
runs around the margin of the pocket in its outer bounding fold. This 
by its contraction would seem to purse the opening of the pocket. The 
second set of muscles are those that I will call the protractors of the 
pockets. These are two in number on each side. They are spread out 
in the skin of both the inner and outer posterior portions of the pockets, 
and their fibers converge forward to finally form somewhat definite 
bands. The outer of these is attached in the skin at the origin of tlie 
fold on the upper jaw. The other is attached to the lower attachment 
of the fold at the lower jaw. These two muscles thus surround the 
po(;ket, and their contraction pulls its recess forward to the opening of 
the vestibule. The third set of nuiscles are the retractors of the pocket. 
These arise funnel-wise from surface of the pocket, both on its inner 
and outer aspects, and they run backward and dorsally ])arallel to the 
fibers of the latissimus dorsi and totally free from the skin. They form 
a band three or four inches long and nearly an inch wide, and are 
filially inserted in the tendinous aponeurosis that covers the inser- 
tion of the latissimus dorsi and is attached to the neural spines of the 
anterior lumbar vertebme. These by their action retract the pockets." 

"Bull, U. S. Geol. aud Geog. Survey Terr., iv, No. 1, Feb., 1878,214-215. 
t Science, xxiii, Feb. 23, 1894, 102-103. 



The sterno-mastoid muscle arises by a teudiuous aponeurosis from the 
manubrium of the sternum and is inserted into the mastoid process of 
the squamosal immediately behind tlie auditory meatus. 

The clei do-ma staid arises from the middle part of the clavicle and is 
inserted on the upper or dorsal aspect of the mastoid process of the 
squamosal immediately over or above the insertion of the sterno-mas- 
toid. Its libers are but little separated from those of the trapezius. 

The trapezius muscle arises from the surface of the outer 
third of the clavicle and the adjacent acromial process of the scapula 
and the spine of the scapula for its entire length : near the median line 
its fibers seem to be continuous with those of the median part of the 
hitissi)iiiis dorsi. It is inserted on the lambdoid crest for its entire 
length, its outer edges being continuous with the insertion of tliecleido- 

The rhomboidcus lies immediately below the trapezius. It is much 
less extensive than the latter, but considerably thicker. It arises from 
the superior face of the spine of the scapula and the adjacent anterior 
part of the vertebral border of the sca])nla, and is inserted into the pos- 
terior face of the lambdoid crest immediately beneath the insertion of 
the trai)ezius. 


Turning now from the consideration of the individual muscles to the 
study of tlte origin of the complex movements of the jaw in chiseling 
and slicing the food, even greater dififlculties are encountered. The 
following attempt, therefore, is subject to correction. fl 

(1) The act of chiseling. — From what has been said it appears that 
the act of chiseling" is performed in essentially the same way in both the 
platyecphalic and dolichocephalic members of the group, and that it is 
due to the joint action of the masseter and temporal muscles, the former 
being more effective than the latter. 

The thin enamel edge of the upper incisors is used chiefly as an 
anchor to fasten the cutting machine firmly to the object operated upon, 
while the lower jaw plays back and forth like a drill in accomplishing 
the work. The exserted part of the upper incisors, therefore, is curved 
downward and inward, and the edge, which is very thin and sharp, is 
broken by one or more grooves, which enable it to penetrate hard sub- 
stances more easily than if it were straight. The face of the lower 
incisor slopes strongly forward as well as upward and the axis of its 
movement in cutting must be obliquely forward and upward. The 
principal muscle concerned in chiseling is the masseter, which is aided 
by the temporal, and in some cases also probably by the pterygoids. 
The way the posterior part of the ramus of the mandible curves upward 


ill tlie arc of a circle lias a biglily important bearing- on the efficacy of 
the action of the niasseter, and lias doubtless been molded into its 
l)iesent sliape by this all-important muscle. The rostral part of the 
niasseter is nearly horizontal; from its aponeurotic origin on the sides 
of the rostrum it spreads out posteriorly and is inserted broadly over 
the posterior curvature of the upturned ramus of the mandible, its 
action being- to draw the mandible as a whole directly forward. The 
main body of the muscle is uearly vertical, but slopes slightly back- 
ward from its maxillary origin to its insertion on the outer side of the 
mandible; in contracting draws the jaw slightly forward and power- 
fully upward. In those species in which the zygomatic part of the 
niasseter is nearly vertical instead of transverse this part of the muscle 
aids the rest in moving the jaw forward and upward. The masseter is 
aided still further by the temporal muscle, which, using the condyle as 
a fulcrum, moves the lower incisors upward. 

(-') The act of sUcin;/. — The act of slicing the food is performed in dif- 
lercnt waysin the two series of animals, being chietly ato and-fro move- 
iiK'iit in the (loHchocephalic species and a transversely oblique rotary 
movement in the liJaiyeephalic species. In the dolichocephalic species 
botli the forward and backward movements are important, while in the 
pi at ycephaltG i^liecies the backward movement is merely one of recovery. 

In the (lolichocepJialic series, therefore, the forward movement produced 
by the masseter reipiires a powerful counter movement in bringing the 
•jaw bick. This is supplied, apparently, by the joint action of the 
digastric and the deep part of the temporal. The latter holds the teeth 
firmly together and draws the jaw slightly backward, while the digastric, 
contracting at the same time, pulls the jaw powerfully backward, the 
superficial part of the temporal, which is inserted ou the coronoid proc- 
ess, preventing it from opening the mouth. 

In t\\& platycephalic series, as already stated, the principal movemeut 
is obliquely transverse, the jaw being drawn outward and forward. 
The muscles proilucing this action are the zygomatic part of the mas- 
seter and the pterygoids. It is probable that they are largely aided by 
the deep iiorticm of the temi)oral, which is inserted into the pit on the 
outer side of the posterior molars. The fibers of this ]>art of tlie tem- 
poral muscle being- vertical, bring the teeth firmly together and draw the 
under jaw slightly outward, which movement, in connection with the 
angle of truncation of the crowns of the teeth, must result in the trans- 
verse rotary motion. 

The mouth is opened by means of the digastric muscle, which is 
beautifully adapted to this end, its origin taking hold of the posterior 
part of the cranium on each side of occipital condyles, while its iuser- 
tioii is carried forward all the way to the symphysis of the jaw. The 
digastric does not ai)pear to be assisted by any other muscle iu i)erform- 
iug its function of opening the mouth. 



[NO. 8. 


Throughout the Geomyidw the masseter muscle has profoundly modi- 
fied the form of the skull and the character of the teeth, and is largely 
responsible for tlie extraordinary cranial peculiarities that distinguish 
the several genera. Perhaps it would be better to say that slight dif- 
ferences in the direction of the principal movement of the jaw in grind 
ing the food, which have proved an advantage to the animal, have by 
natufal selection developed certain fibers or parts of the muscle at the 
expense of other parts, and that the differences thus origiaated have 
been i)erpetuated and intensified until the muscle has in turn molded 
the bones to which it is attached, and also those with which it comes 
in contact, thus altering the form and proportions of the cranium as 
a whole, and giving rise to extreme variations in the size, shape, and 
position of the zygomatic arch and in the development of the angle of 
the jaw. At least two very distinct typi^s of skull have been estab- 
lished in this way — a broad ot platycephalic type (pi. 3) and a narrow 
or dolichocephalic type (pi. 5).t 

By contrasting the accompanying figures of representative skulls of 
these two types, with respect to the areas of attachment of the princi- 

riG.49. — Side view of skull of Macrogeomyn doLichucephalus, showiug relationa of mandiblo, and 
fossae for attachment of muscles. 

a Anglo of mandible. 
ic luci.sor capsule. 
jo Jugal origin of masseter. 
711 Mastoid process of mastoid bulla. 
ms Mastoid process of s(iuaniosal. 

mf Masseteric fossa. 

mo Maxillary origin of main body of masseter. 
m«.? Mandibular slielf (leading to angle in Pia- 
tygeomys gymnurus). 

pal parts of the masseter, the action of the muscle and its effects on 
the skull may be better understood. Without rei)eating the detailed 

"P^'or an irnijortaut chapter on the general snbject of the intineuee of the inu.scles 
in shaping the skull in the Rodentia, see Herluf Winge, Jordfundne og nnlev. 
Gnavere fra Lagoa Santa, Minas Geraes, Brasilieu, 1888, 103-110. 

t These extremes in the form of the skull are brought about mainly by alterations 
in the superficial or outer parts, the fundamental structures and relations remaining 
very much the same in both, as shown by sectionized skulls (pis. 17 and 18). 



descriptions already given under the liead of the muscle (p. !M)), it may 
be stated that the principal part of the masseter arises from the side of 
the maxilla in front of the zygomatic arch, and from the adjacent parts of 
the premaxilla and the maxillary root of the zygoma (fig. 49, mo). It is 
inserted upon the outer side of the mandible, and the area covered by its 
insertion — the masseteric fossa — extends from the angle to the plane of 
the front of the premolar (fig. 4!), mf). Its origin, insertion, and relations 
are essentially the same throughout the group. The jugal part arises 
from tlie horizontal arm of the zygoma and is inserted upon the upper 
side and end of the angle of the jaw. Its size, form, area of origin, axis, 
and relative imi^ortance differ conspicuously in the various members of 
the series. In some forms it arises from the entire length of the hori- 
zontal part of the arch (fig. 50, jo); in others from the j^osterior part 
only (fig. 49, /o). The upper limit of its origin is marked by an oblique 
line and a change of direction in the outer face of the jugal* 

Effect on the skull. — In the long and narrow skulls, of which Macro 
geomys dolichocephalus may be taken as a type, the great body of the 

Fiu.50. — Side view of skull oi Platy geomys fji/umicrui nhowiog relatious of inaudible ami fos.sii^ for 
atta('limeut of muscles. Letteriug same as in fig. 49. 

masseter is parallel to the side of the face, its function being to close 
the jaws firmly and draw the mandible forward. Its princii)al origin 
is maxillary, the jugal part being small and posterior to the plane of 
the middle of the orbit (fig. 49, ;>>). The resulting i^rincipal movement 
of the jaw is antero-i)osterior. The action of the muscle has narrowed 
the zygomatic arches, rounded off their anterior angles, and lifted them 
out of the way until the horizontal part of the arch is much nearer the 

* Owing to the scarcity of material for dissection tlie masseter muscle itself has 
been actually examined in two forms only, namely, Geomiisbursarins and Miicrofjcomiia 
dolichocephalus. Its relations in these species, studied in connection with the well 
defined fossae on the skull marking its origin and insertion, furnish a very good 
guide to its modifications and to the jiart it has played in producing the several 
types of cranium known in the group. 



[NO. 8. 

top of tbe skull in front tliaii l)eliin(l (tig. 40). The fibers of tliejugal 
braneli are nearly vertical, and are of little use except in drawing up 
the back part of tbe jaw. This may be seen from fig. .lU: the muscle 
passes downward from the zygonni {.zy) to the angle of the Jaw [a). 

In the broad and fiat skulls, of which Flatygeomys (jymnnrus may be 
taken as a type (fig. 50), the Jugal branch of the masseter is largely 
developed, its function being to move the jaw sideways at the same 
time that the maxillary i)art brings the teeth firmly together. The 
resulting principal movement of the jaw is obliquely transverse. In 
producing this lateral movement tlie jugal branch is aided by the 
pterygoid muscles, but the latter must have played a very subordinate 
part in molding the skull. The jugal part of the masseter in the 
j)latycephalic series is not only of relatively large size, but the area of 
its origin is greatly extended (fig. 50, jo) and the axis of its fibers has 
become more nearly horizontal than vertical (fig. 54, a to zy). Its origin 
occupies the outer and inferior surface (and i^robably most of the 
inner surface also) of the horizontal part of the zygomatic arch for 



KlG. 51. — Macfogeomys dulichvcephalus. Via. h'i. — Flatygeomys gyinnurus. 

Posterior part of craiiiiiiii from above, showing relations of maudible iu place. 

a Angular process of uiaiulible. //• Frontal. 

cp Corouoid prooes.s of mandible. pa Parietal. 

ic Incisor capsule (covering root of lower so Supraoccipital. 

incisor). sq Squamosal. 

ip Interparietal. 2y Zygoma. 

its entire length, its anterior end being in front of the plane of the 
orbit. The action of this part of the masseter has drawn the zygomatic 
arch far outward and has pulled the anterior angle downward until 
the latter is lurther from the plane of the top of the skull than the pos- 
terior end of the arch. The angle is thus drawn down until it reac^hes 
four-fifths of the way from the plane of the toj) oi the skull to the plane 
of the molar alveolus, overreaching and overarching the maxillary or 
principal part of the masseter muscle, which ojx rates beneath it (tig. 
50, which should be cdiitrasted with fig. 40 of Macrof/coniys doUchoceph- 
aius). The insertion of the muscle has produced an equally extraordi- 


JAN., 1S95.] 



nary effect upou the shape of the under jaw. The sides of the Jaw are 
not only spread widely apart in conformity with tlie great breadth of 
the skull, but in addition tlie fibers of tlie uiasseter that are inserted 
on the angular process have stiniuhited this process to push out side- 
ways until it reaches off like a long arm at nearly a right angle to the 
axis of the skull (figs. 53 and oi, a)* The lengthening of this proc- 
ess was clearly necessitated in order to coutinue the effective action 
of the muscle. Furthermore, the segregation and specialization of the 

Fig. 52. —Macrogeoniys dolichneephalug. Fig 54. — I'latygeomys gymmuus 

Transverse vertical section of skull, with mandible in position, showing relations. 

a Angular process of mandible. 
ale Alisphenoid canal. 
alh Horizontal arm of alisphenoid. 

c Con<lyle of mandible. 
cp Coronoid process of mandible. 

/ Angle of crowns of closed molar.i. 

ic Incisor capsule (covering root of lower in- 
cisor) . 
np Narial passage. 
pa Parietal. 
pf Pterygoid fossa. 
iq Squamosal. 
zy Zygoma. 

two parts of the masseter in iho, platycephalic series has resulted in the 
production of a long and well-defined horizontal shelf extending for- 
ward from the angle of the jaw to the base of the ascending ramus 
(fig. 50 mss). This shelf is totally wanting in Macrogeomys doliehoceph- 
alus and the other doUchocephalic forms in which the jugal part of 
the masseter is relatively unimportant and the principal movement of 
the jaw is fore and aft instead of transverse. The relations described 
may be seen to good advantage in the accompanying drawings (figs. 

Effect on the teeth. — While from the nature of the case it is ciearly 
impossible to observe exactly what happens, either in the muscles or 
the teeth, during the act of mastication, it is at the same time i)ermis- 
sible to draw certain inferences from the mechanical construction of 
the apparatus. In the case of tlie teeth, considered as the focus of the 
cutting machine, it has been already shown that two types exist, one 

* In M. dolichocephalus the angle projects only 2| mm. beyond the plane of the 
zygoma (fig. 52), while in P pymnurus it jtrojects 10+ mm. 


in which the crowns of the upper inteiinediaiy inohuvs are broadly ellip- 
tical and bear two enamel i)lates (one on eueh face); the other in which 
the crowns are narrowly elliptical and bear only one enamel plate 
( which is on the anterior face). It has been shown further that the pres- 
ence of two enamel plates is always correlated with an anteroposterior 
movement of the jaw, and that tiie presence of a sinj>le plate is always 
correlated with an obliquely trausv^erse movement of the Jaw. A care- 
ful study of the cutting- blades in each instance shows that an antero- 
posterior movement is accompanied by a to-aud-fro i)laning' action in 
which two enamel blades are serviceable; and that a. transversely 
obli(iue movement is accompanied by a lateral shearing- action in which 
only a single blade can be used. In accordance with the well-known 
law that useful structures are preserved and useless structures sup- 
pressed, it is logical to infer that tlie direi'tion of the dominant move- 
ment of the jiiw has determined the presence or absence of the posterior 
enamel plate; and since the movement of the Jaw is controlled by the 
masseter muscle, it is evident that the number of enamel plates on the 
u])per intermediary molars may be traced back to the influence of tiiis 

In the course of the evolution of the two types Just described it seems 
evident that as soon as the principal movement of the Jaws in the line 
leading- to Macrofjeonii/.s doUchocephaluH came to be fore and aft it was 
settled that the form of the posterior part of the cranium should be 
narrow; that the angle of tlie under Jaw should b(^ shortly truncate; 
that tlie grinding- teeth should be broadly elli|)tical, and that the poste- 
rioi- enamel plate of the upper series should be retained; and when the 
priiKii)al motion of the Jaw in the ancestors of Phityfjeomys gymnurm 
v-Mwy to be obliquely transverse, from that moment it was predeter- 
mined that the hinder jiart of the skull should be broadly expanded; 
that a long- arm like process should spring from the angle of the jaw; 
that the grinding teeth should be transversely flattened, and that the 
posterior enamel i)late of the upper series should disappear. 


Genus GEOMVS Rafinesque, 1817. 

Pis. 1,7; 9, 12; pi. 1.5, lags. 11 Jind 12; pi. 17, lig. :^: pl.l8,tig.l; pi. 19, fig. :5, ami text 

fig. .5.5; maps 1 ;ni(l 4.) 

Type Mus iuza Onl. 1815, from Au( a, (Jkorgia. {z^Geomi/s phietis Raf., 1817). 

Geomi/s Raliuesciiic, Am. Monthly Magazine, II, No. I, Nov., 1817,45. Type G. pine t is 

Raf. (=.yM.'* titza Ord. 1815), from pine liarrens near Augusta, Ga. 
Diplostuma Ratiuesqne, Ildd, 1817, 44-45. 
Saccophonis Kuhl, Beitriige zur Zool., 1820, 65-66. 
Pseudostomn Say, Long's Exi)d. to Rocky Mts., I, 1823,406. 
Asromys Lichtenstein. Abh. Akad. Wiss. Berlin ^822), 1825,20, fig. 2. 

Dental characters. — Upper pieinolar with three enamel plates (the 
posterior absent). Tapper pni decidedly longer than lower (in the other 
genera they are subeqnal); shaft of upper pm decidedly concave for- 
ward, except in a single species {G. IvJescens). First and second upper 
molars with two enamel plates each, the posterior complete; posterior 
curvature of m^ and anterior curvature of iii, hardly ai)parent. 

Last upper molar a single subcylindric or subtriangular prism with- 
out lateral sulcus on either side (and consecpiently without heel) : outer 
enamel plate normally straight; inner and outer plates commonly sub- 
equal, or outer somewhat shorter, both reaching posterior face of tooth. 
I'pi^er incisor strongly hisulcatc (fig. 1*2^ and 2li '; pi. 15, figs. 11 and 12). 

Cranial characters. — Skull simi)le. without any very striking external 
characters. Orbitosphenoids small and narrow, not reaching alisplie 
noids (pi. 17, fig. 3); sphenoid fossie C()rre^l)ondingly elongated, reach- 
ing forward to orbital plates of frontal; alisphenoids short posteriorly, 
ending on floor of brain case about on plane of front ends of audital 
bulhe; pterygoids large, always forming more than Imlf of the palato- 
pterygoid extensions; mesethmoii plate large, some wliat rectangular, 
nnich longer than high, and wholly superior to vomer (not dipping- 
down between vomerine wings as in Pappof/romys); endoturbinals col- 
lectively forming a quadrate plate, the anterior border of which is ])ar 
allel to the cribriform plate (pi. 19, fig. 3) ; first endoturbiual rounded 
and only vSlightly expanded anteriorly, its inferior border fiiHing (as 
the OS planum) in the front of the others and articulating with the 
anterior third of the internal vertical plate of the maxilla — the os pla 
num thus extending anteriorly in front of the lower endoturbiual nuich 

further than the length of the latter. 




In the elongated sknlls of Geomys bursarius and tuza the lower part 
of the sphenoidal fissure, on the floor of the orbit, differs from its con- 
dition in any of the other groups (fig. 55). In all of the others a fenes- 


Fig. 55. — Side view of r^knll of Geomys hursariiis from outside, zygomatic 
sawed off to sliow bottom of orbit. Animal a fully adult S , from Knoxville, I 
(This Hgnre should be compared with the corresponding view of Cratoc/eomys 
riam'u fig. 4.) 

1. Infraorbital foraiiien. 

2. Posterior (orbital) opening of infraorbital canal. 

3. Vacuity in front of prespbenoid and ascending wing of palatine. 

4. Vacuity in prespbenoid, l)ebind ascending wing of palatine. 

5. Optic foramen (in orbitoax>benoid bone). 

fl. Foramen rotundum and foramen ovale (whicb have hero coale.'iced). 

7. External auditory meatus. 

8. Spbenoidalfi.ssnre (upper part). 
.\scendiiig wing of vertical plate of palatine. 
Condyle of exoccipital. 
External pterygoid plate of palatine bone. 
Hamular ])rocess of pterygoid bone. 

/. Lachrymal. 
n. Mastoid proce.s.s of raa.stoid bulla. 

6. il.Tstoid bulla. 
«. Mastoid process of squamosal. 
X. Maxilla. 
/(. Nasal. 



Paroccipital process of exoccipital. 



sq. Squamosal. 
tb. Tympanic or nudital bulla. 










truin (fig. 4,")* penetrates tlie iiiterorbital septum, which at this point 
consists of the presphenoid oul^'. In Geomys bursarius and tuza the basal 
part of the sf^henoidal fissure is unusually broad, and the septum at 

* In some cases, particularly in Orthoyeomys and Zjigoyeomys, this fenestrnm is sub- 
divided into two or even three parts, but they all invariably penetrate the prespben- 
oid; they are never in front of it. 


its bottom, which here consists of both palatine and pres]ihenoid, is 
l)i'r(orated by two fenestra, whicli hiok completely throngh the sknll 
from orbit to orbit. The posterior is the usual opening- in the anterior 
part of the prespheiioid (flg. 55,^) ; the other is in front of the pre- 
sphenoid and is bounded anteriorly by a process from the maxilla, which 
here rises to join the frontal (tig-. 55,'*). Hence in Geomys hursarhis 
there are three openings in the bottom of the orbital fossa, arranged 
seriatim, one in front of the other. Tlie first is the posterior outlet of the 
infraorbital canal (fig-. 55,-); the second is the vacuity here mentioned, 
which penetrates the skull in front of the pres])henoid (fig. 55,^); the 
third is the usual fcnestrum in the anterior part of the presphenoid 
(fig. 55,'*). The ojiening in front of the presplienoid is completely sur- 
rounded by the maxilla and ascending wing of the palatine — the former 
bounding it in front, the latter behind — for the ascending wing of the 
vertical plate of the palatine (fig. 55, ajH) here rises along the front of 
the presphenoid between the two fenestra in question and articulates 
with the maxilla, the orbital plate of the frontal, and the orbitosphe- 
noid. (See also fig. 10.) 

Tlie condition here described has not been observed except in the 
elongate skulls of Geomys bursarius, tuza, a.i\d per sonat us, and is imper- 
fectly developed in the latter. It reaches its highest development in 
Geomys bursarius, and does notocccurin the closely related G. lutescens, 
which has a short skull. A condition simulating it sometimes exists 
in Orthogcomys, in Avhich there are several (usually two or three) small 
jierforations in the anterior part of the presphenoid, but the relations 
of the ascending wing of the palatine are not the same. Very young 
specimens of Cratogeomys resemble the adult of Geomys in the presence 
of a fenestrum in front of the presphenoid and ascending wing of the 
palatine, but the fenestrum disappears as the animal matures, a vestige 
of it remaining as a foramen (on each side), which opens from the floor 
of the orbit obliquely forward and downward into the narial passage. 

The genus Geomys, even as here restricted, comprises three series or 
groups of species: (1) the texcnsis-brericeps series, (2) the tuza series, 
and (3) Geomys busarius. 

(1) The texcnsis-breviceps series inhabits Texas, Louisiana, Arkansas, 
and the Great Plains, and includes eigiit species and subspecies, as 
follows: arenarius, tcxensis, lutescens, breviceps,breviceps sagittaHs, brevi- 
ceps (ittwateri, personatiis, and personatus fallax. Most of these, par- 
ticularly arenarins, texensis, and brericeps, are small generalized forms 
suggesting relationship with Ihomomys and Pappogcomys. Indeed, 
these animals are very much alike in many ways and the skulls agree 
in general form, lightness, in the small rounded brain case, slender 
and nearly parallel zygomata, narrow pterygoids, and many other 
characters, though dilfcringconspicuoiisly in the teeth. It seems evident 
that they are but little removed from the trunk line of the group, and 
that both the tuza and the bursarius series are offshoots from the bred- 


cejys stem. Geomys hreviceps seems to be the central or parent type 
from wWcb three widely different species originated, tuza on the east, 
bnrsariiis on the north, and luteseeiis on the west. To tlie eastward 
only ai narrow gap separates the range of hreviceps from that of niobi- 
lensis of the tuza series, which, though specifically distinct, was evi- 
dently derived from the hreviceps stock. Still further east mohileusis 
passes in totuza. On the west hreviceps shades toAvard and probably 
will be found to intergrade with lutescens. On the north only a nar- 
row hiatus separates it from hnrsarins, the most specialized type of 
the series. Specimens of hursarins from southern Missouri suggest 
that the gap between it and hreviceps is not very wide; if continuity of 
range between the two forms is anywhere found this gap may be 
bridged even at the present time (see map 4). 

(2) The tuza series inhabits the South Atlantic and Gulf States south 
of the Savannah Kivcr and east of the Mississippi (mah 4, A), and com- 
prises three forms, tuza, tnza mohilensis, and tuza floridanus. They are 
locally known by the singularly inappropriate and misleading name 
'Salamander.' The members of the tuza series agree among themselves 
and differ from the remaining forms of the genus Geomys in having 
longer and more naked tails, and in numerous cranial characters. The 
shape of the skull in potile is decidly convex, the rostrum long and 
decurved, the nasals long and slender and constricted in the middle, giv- 
ing them a somewhat hour-glass shape. The interparietal is perma- 
nently distinct from the supra-occipital and is normally much larger 
than in any of the other groups, though in G. mohilensis it is nearly 
obliterated in old age by the encroachment of tlie ridges that unite to 
form a sagittal crest. 

The tuza group differs not only from hursarius, but from all other 
known members of the family, in the disproportionate length of the 
upper premolar in relation to the other molarilbrm teeth. It is merely 
double the length of m-^. The lower premolar is much shorter, particu- 
larly in jioridanus. 

(3) Geomys hursarins inhabits the u])per Mississippi Valley (map 4, b) 
and stands alone at the end of the northern branch, just as Geomys tuza 
occupies the end of the eastern branch of the restricted genus Geomys. 
The skull is elongated and angular, the frontal compressed between the 
orbits, the palatopterygoids broadly Ungulate, and the sagittal crest 
high; but the most important departure fi'om its allies is found in the 
anterior part of the craniofacial axis, and consists mainly in the broad 
articulation of the ascending wings of the palatine bones with the hori- 
zontal shelf of the orbitosphenoids, and in the presence of a fenestrura 
looking completely through the skull in front of the presphenoid. G. 
hursarius presents the extreme of differentiation occurring in the bisul- 
cate series inhabiting the United States. 

The following brief tabular statement of some of the cranial char- 
acters of the three members of the ^»vrt group may facilitate the identi- 
fication of specimens: 


IHfferentiftI cr(iiti((l iharaitcm of the ineinhcr.'s nf llie tiiza t/roiqi. 

Tcraporal impvossions 

Frontal (iiiteroibitally) 

Ascending brauclies of premaxilla 


Audital bnllii! 





United in a sagittal crest . . ! Distant 1 Distant. 

Very broad ! Narrow ; Narrow. 

Motleratu ; Moderate i Very broad and 

j ! blunt. 

Narrow, sides i)arallel- ... Lingulate-ctineate Lingnlate eune 

i I '^^^' 

Small Small i Large. 

Deeply notched posteriorly Not notched i Not notched. 


[Based on skulls of adult males only.) 

(1) .TUGAL equal to or shorter thai) basioecipital (measured from condyle), 
a' Sagittal erestprenenl. 

ft' Zygomata strongly angular (standing out at right angles) ; jugal 
broadly rounded anteriorly. 

Size large ; audital biilbe nornial persouaiits 

Size medium; audital buUie short and swollen (almost 8ubglobular)./rt?/ax 

h- Zygomata rounded ; jugal narrow anteriorly ; size small safjittaJis 

a- Saijiltal crest absent. 

Temporal ridges prominent ; squamosal arm of zygoma ending in 

a knob arenarins 

Temporal ridges not prominent; squamosal arm of zygoma not 

ending in a k nob iexensis 

(2) Jugal longer than hasioccipital (measured from condyle). 

c' Sagittal crest strongly dcreloped — long and high; size larg<«t hursarius 

c- Sagittal crest feebly developed or absent; size medium or small. 

(P Nasal bones hour-glass shaped; strongly constricted near middle. 

e' Temporal impressions uniting in sagittal crest mobilensis 

e'^ Temporal impressions not uniting in sagittal crest. 

Audital bulhe small; not swollen; nasals broad posteriorly tnsa 

Audital bulhe large, swollen; nasals narrow posteriorly .. .floridanii't 
rf^ Nasal bones not hour-glassed shaped; slightly or not constric- 
ted near middle. 
/' Frontal strongly depressed interorbitally ; zygomata l)r()adly 

rounded; nasals very narrow posteriorly, notched behind. ftrtr(cej;s 
/^ Frontal slightly or not depressed; zygomata angular, 
strongly divergent anteriorly. 
Temporal ridges prominent, divergent anteriorly; nasals 

abruptly narrow and convex posteriorly attwateri 

No temporal ridges; temporal impressions parallel or 
meeting in sagittal ridge; nasals truncate or emargi- 
uate posteriorly liitescens 

(Frontispiece and pi. 7. fig. 1; pi. 13, tig. 9; i)I. 15, fig. 12.) 

Mas tnza Ord, Guthrie's Geog.,2d Am. ed., Ii, 1815, 292 (based on Mitchill's "unde- 

scribed little <iuadruped of Georgia'" — atm postea). 
Geomys pinetis Rafinesque, Am. Monthly Magazine, vol. ii, No. I, Nov., 1817, 45 (type 

of geuus Geomys). 
Undescrihed little quadruped of Georgia, Mitchill, New York Medical Repository, V, 

1802, 89. (Descr. orig. on which the name .Vns tuza of Ord was based.) 

7433— No. 8 8 


Eamster of Gcoryia, Audersou, 2d Am. from 8tli London ed. of Bewick's Hist, of 
Quadrupeds, 1848,* 326 (accompanied by figure Avith claetik pouches properly 
turned in). 

Type locality. — Pine barrens uear Augusta, Georgia, t 

Geographic distribution. — Pine barrens of (leorgia ( and probably 
northern Florida also), within the Anstroriparian fannal area (map 4). 

General characters. — Size medinni or rather large; tail long atid 
naked; feet moderately well haired; a small naked pad on end of nose. 

Color. — Upper parts cinnamon brown, strongly tinged with fulvons 
in fresh pelage; only a faint trace of darker median dorsal stripe; 
under parts dull ochraceous buff; hairs of feet whitish. 

Cranial characters. — Skull rather large and angular (PI. 7, fig. 1), its 
upper surface convex in i^roflle (due in part to the strongly decurved 
rostrum and in part to the absence of sagittal crest); zygomata diver- 
gent anteriorly, the maxillary root sloping strongly backward; temporal 
impressions never uniting in a sagittal ridge, but forming permanent 
temporal ribs, which in the males are elevated on both sides and sepa- 
rated by an interspace or sagittal area 3 to 4 mm. in width. In the 
females the intersj)ace is broader and usually thickened so that it is 
flush with the top of the temporal imj^ressions. Interparietal very 
large and broad. The frontal is narrow interorbitally; postorbital 
prominences marked; palatopterygoids lingulate-cuueate, the base 
slightly or not excavated on outer side; audital bulhe small, normal; 
basioccipital strongly wedge-shaped, truncate anteriorly. 

Skulls of (t^. tuza may be distinguished from those of mohilensis by the 
presence of distant temporal ridges instead of a sagittal crest; by the 
narrow frontal (interorbitally); by the lingulate-cuneate (instead of 
narrow strap-shaped) palatopterygoids, and by the very large inter- 
parietal which is not notched behind (fig. G e). Skulls of tuza differ from 
those oi Jioridanus in much narrower ascending branches of premaxilla, 
broader nasals posteriorly, more strongly wedge-shaped basioccipital, 
and much smaller audital bulhe. The relationship with Jloridanns is 
much closer than with mohilensis. The protile of the top of the skull 
is more convex than in either of the others. 

Measurements. — Average of ten males from type locality (Hollywood, 
Georgia, 11' miles soutli of Augusta): Total length, 2G9; tail vertebni?, 
89,5; hind foot, 34.4. 

* The copy cited by Coues (Monograj)hs of N. Am. Rodentia, 1877, 615 footnote) has 
the same pagination, but a somewliat different title page (different publisher) and is 
not dated. The eighth Loudon edition of Bewick was published in 1824. The 
only mammals described in the American reprint not in the original are the grizzly 
bear, hamster of Georgia, and mammoth. 

iThe tj'ps specimen was sent Dr. Mitchill from Augusta, Ga., in July, 1801, by 
.Josiah Meigs, president of the University of Georgia. In the letter that acco.iipa- 
nied the spccimeu Mr. Meigs said: "For the space of about 100 miles, between 
8avannali and Augusta, the land on each side of the road is almost covered l»y the 
heaps of loose earth raised by it." — New York Medical Repository, Y, 1802, 89. 

JAN., 1895.] 


Average of nine females from same j)]ace: Total length, 249; tail 
vertebra', 82 ; liiud foot, 32. 

For cranial measurements see Table C, p. 208. 

Specimem examined. — Total number 32: twenty from type locality, 
Hollywood, 12 miles south of Augusta, Georgia; and twelve from 
Butler, Georgia, (latter not typical). 

General reniarls. — SpeL-imens from Butler, near the western border of 
Georgia, are intermediate between fuza and mobilensis. In color they 
resemble the latter, while in cranial characters they are nearer the 

It is an interesting fact that the first description of this species — and 
not a bad description either, considering it was written nearly a century 
ago — was from the pen of a member of Congress, the Hon. John Mil- 
ledge, Ilepresentativ^e from Georgia. It was published by Dr. Mitchill 
in the New York Medical Repository in 1802 (vol. v, p. 89), and runs as 
follows: ''One of the little animals that burrows in the pine land, only 
known in Georgia, was caught by Mr. Stephen Pierce, living midway 
between Savannah and xVugusta. Its body is of the length and thick- 
ness of a common-sized rat, amd of the same color: the head between 
that of a rat and a mole, with small whiskers and short snout: the tail 
without hair, but shorter than that of a rat : the fore feet like those of 
a mole, with nails near an inch long: the hind feet like those.of a rat, 
but the nails not of the same length, each foot having five claws : very 
sparkling small eyes: also short ears: teeth like a squirrel, and full as 
long. On both sides of the jaw, externally, are sacks or wallets, where 
it deposits its food, and each will contain as much as can be put in a 
large tablespoon. Little or no fur, and the hair of the length of a wood 
rat. The whole face of the pine country is covered with little mounds 
made by this animal, of the circumference of a peck, and from 6 to 8 
inches high. It is by no means active, but remarkably fierce. No 
common wooden place of confinement can hold it long, as it gaaws its 
way out. It lives entirely on roots, and is very fond of the sweet 
potato, and often i^roves injurious to the planter by getting under'his 
stacks. It ai^pears to move nearer the surface in the spring and fall 
than at any other season. It is surprising, that though the work of 
this creature is seen throughout the country, in the region of the long- 
leaf pine, and in that region only, yet sach is its skill in burrowing, and 
acuteness of hearing, that there is no animal in all our State so seldom 
caught or seen." 

(PI. 7, figs. 3 and 4; PI. 10, fig. 1; PI. 14, fig. 16.) 

Pseudostomn Jior'ulana And. and Bach., Quadrupeds of Xorth Am., Vol. iii, 1854, 242- 

Geomtjn tiiza Goode (not Ord), Powell's Report Colorado R?ver, 1875, 281-285 (habits). 

Type locality. — St. Augustine, Florida.* 

*Auilubon and Bachman did not discriminate between the Georgia and Florida 
animals, but all of their Florida specimens came from St. Augustine. 


General characters.^^umhiv to G. tnza, but much (linker in color; 
fore feet larger; tail sHghtly more hairy; <lifi(er.s also in cranial 

Color. — Upper parts dull sooty-plumbeous, becoming cinnamou-drab 
on the sides; under parts plumbeous, more or less washed Avith buffy; 
an irregular white patch under chin and throat. 

Cranial characters. — Skull long, with very angular zygomatic arches, 
much as in tuza and mobilensis. G. floridanus differs from G. tuza in 
broader and blunter ascending branches of premaxilla, narrower nasals 
posteriorly, somewhat broader jugals anteriorly, more rectangular (less 
strongly wedge-shaped) basioccipital, and much larger audital bulhe; 
from mohilensis in much larger audital bulhe, narrower frontal, less 
spreading and more depressed arches, much broader ascending branches 
of premaxilla, .less flattened brain case, lingulate-cuneate instead of 
narrow palatopterygoids, and in the presence of temporal ridges instead 
of a sagittal ridge. The angular process of the mandible is nuich less 
deeply notched at base anteriorly. In G. floridanus the interspace 
between the two grooves of tlie upper incisor is broader than in either 
tuza or 'mobilensis, and the head of the jugal is more deeply mortised 
into the maxillary arm of the zygoma. 

i^pccimens examined. — Total number 25, from the following localities 
in Florida: Chattahoochee, 2; Pomona, 4; Gainesville,!; San Mateo, 0; 
Tarpon Springs, 12. 

Measurements. — Average of three males from San Mateo, Florida 
(measured in flesh by Dr. W. L. Ralph) : Total length, 288; tail vertebr;e, 
94 ; hind foot, 35.5. Average of three females from same locality : Total 
length, 235; tail vertebrie, 77 ; hind foot, 33. For cranial measurements 
see Table C, p. 208. 

General remarls. — The foregoing description has been drawn up from 
specimens from San Mateo, Putnam County, Florida,* only 25 miles 
from St. Augustuie, the type locality of the species. Specimens from 
further south on the peninsula are somewhat different. 

The best and almost the only authentic account of the habits of this 
species is from the pen of the eminent director of the TT. S. National 
Museum, Dr. C. lirown Goode, by whom it was contributed to Cones' 
monographic paper on the group, published in 1875. f Dr. Goode kept 
a number in confinement for several weeks and was thus enabled to 
make the "following interesting observations on their habits. He says: 
" They may easily be coniined in a wo®den box, with sides 8 or 10 inches 
high, having dry. sand 2 or 3 inches dee»p on the bottom. No cover is 
necessary; I have never seen one look up from the earth, and have 

*These specimens Averekindly presented to me by Dr. W. L. Ralph, of Utica, Ne 
York, who collected them himself and measured them m the flesh. 

t Abstract of results of a study of the genera Geomt/s and Tliomomys. Powell's Expi. 
Colorado River, 4^, 187.5, 21.5-28.J. Addendum B.— Notes on the "Salamander" of 
Florida, by G. Brown Goode, 281-285. 


rarely known them to attempt to escape. They require no water, and 
no food except sweet potatoes. A single potato of moderate size will 
feed a salamander for three days. 

" The senses of sight and hearing seem in them to be very dull. An 
object may be held within a short distance of their eyes without attract- 
ing their attention; but the moment one is touched, he turns with a 
jump, snapping fiercely, much to the detriment of fingers which may be 
near. If two are confined in the same cage, the one does not seem 
aware of the presence of the other, unless they accidentally come in 
contact. Their eyes are small, dull, and without expression. Their 
sense of smell I judge to be very delicate, from the manner in which 
they approach the hills of potatoes. Their motions are surprisingly 
quick and energetic, their activity never ceasing from morning to night. 

" They are very pugnacious, and a rough-and-tumble combat between 
two vigorous males woald seem terrific, if their size could be magnified 
a few diameters in the eye of the spectator. Every muscle of their com- 
pact, elastic, stout bodies is brought into action, and they plunge and 
bite with wonderful ferocity. A battle is usually followed by the death 
of one or both. I have examined them after death and found the 
whole anterior part of the body bruised almost to the consistency of 
paste, the bones of the legs crushed in four or five places. When two 
come together in the cage, their salutation is a plunge and a bite. 

" I watched their burrowing with much interest. They dig by grub- 
bing with the nose and a rapid shoveling with the long curved fore 
paws, assisted by the pushing of the hind feet, which remove the dirt 
from beneath the body and propel it back with great power a distance 
of 8 or 10 inches. When a small quantity of earth has accumulated in 
the rear of the miner, around he whirls with a vigorous flirt of the tail 
and joining fore paws before his nose, he transmutes himself into a sort 
of wheelbarrow, pushing the dirt before him to a convenient distance, 
and repeating the act until the accumulation is remo^'ed, then resuming 
his mining. Any root or twig which blocks his way is quickly divided 
by his sharp chisel-teeth. * * * Tlie direction of the burrows may 
easily be traced by the loose hillocks of white sand which are thrown 
up along the line at intervals of 3 or 4 feet. These are the -dumps' 
made by the burro wer in throwing out his refuse accumulations. Each 
consist of about a peck of loose sand, and, by the casual observer, 
might easily be mistaken for an ant-hill. No opening is visible, but by 
digging under the hill a hole is found, the mouth of the adit to the 
mam tunnel, which may be 3 feet below the surface if made in cold 
weather, but perhaps not more than (> inches if in summer. One of the 
mounds is thrown up in a very few moments. I have seen 30 raised in a 
single night on the line of one tunnel; this would represent nearly 100 
feet of tunneling. I have seen 150 in one continuous row raised in 
about two days ; this would make between 400 and 500 feet of burrow 
completed in that short time, apparently by one little animal, an amount 


of work which may seem incredible to one who lias not watched the 
restless movements of these animated plows, which are seemingly as 
well adapted for piercing tlie sand as birds are for -cleaving the air. 
The bnrrows are about 2i inches in diameter. * * * The nests are 
large chambers, 1 or 2 feet from the main tunnel, with which they are 
connected by side passages, which leave nearly at right angles. Here 
the miners lay up a supply of provisions and the chambers are often 
found to contain a half bushel of sweet potatoes cut up into chunks 
as large as peach stones, and of convenient size to be carried in the 
pockets. * * * In these side chambers the salamanders rear their 
young, building a nest of grass, i)ine needles, and live-oak leaves. 1 
found them breeding in April." 

Dr. Goode remarks that the name ' salamander,' by which the species 
is universally known in the South, " luiiy allude to the safety enjoyed 
by these little animals in their subterranean abodes at the time of the 
devastating fires which sometimes consume the pine forests. After such 
a conflagration has passed over their heads, destroying every other kind 
of life, they are seen at work among the ashes, very good types of the 
salamander of fable." 

Mr. Morris M. Green, who obtained specimens for the Division at 
Pomona, Putnam County, Florida, in June, 1S89, furnished the follow- 
ing notes respecting their habits : " The hills of the ' salamander,' as the 
Florida Geomys is called, are abundant in the pine woods and clearings, 
on rather low and moist land. Their tunnels were from 4 to 24 inches 
below the surface; the hills were thrown up at intervals of from 2 to 6 
feet, and contained about a peck of dirt each. The night and early 
morning seemed to be their favorite time for working. It is very easy 
to trap a 'salamander' when fresh mounds are found. By sweeping to 
one side the heaps of dirt, traces of the hole through which the earth 
was brought and its direction can be easily found. A minute's work 
with the spade will usually expose the tunnel lying to one side of the 
hill. Place a steel traj) in the tunnel, and cover up the breach with a 
piece of pine bark or some palmetto 'fans.' If the breach is left open, 
the animals will carry dirt to shut out the light, and thus clog the trap, 
whereas if the opening is closed they will step in the trap and are 
caught. A break is often repaired within half an hour, or it may be 
left for nearly a day. In mending an opening it is astonishing how 
compactly the earth is packed; in one case an animal closed an opening 
so securely that the tunnel could not be found at all until another shaft 
was sunk in search of it. 

"A 'salamander' caught in a trap is a picture of fury and spite, bit- 
ing at everything within reach of its jaws, and sometimes breaking its 
front teeth in venting its rage on a trap. 

" In the cheek pouches of one were some pieces of pine roots, and 
some grasses were found in the tunnels. The animals do serious injury 
to orange and pear trees by gnawing tlie roots. Sometimes the roots 


JAN., 1895.] 


are gnawed off so completely that the tree can be pusbed over with one 
hand. They also feed on sweet potatoes. But when an animal enters 
a garden or an orchard, and betrays itself by throwing up hills, there 
is no excuse for not ridding the place of it, as it may be easily caught 
in a steel trap. It is claimed that the 'salamander' works near the 
surface from September to March, retiring deeper in the ground during 
the hot season." 


(PL 7, figs. 2, 5, aud 6; pi. 10, fig. 2; pi. 14, fig. 15; text fig. 6, f and g.) 

Typ6 from Mobilf, Bay, Alabama. No. ^^U i ad. U. S. Nat. Museum, Department 
of Agriculture collectiou. Collected April 26, 1892, by Russell J. Thompson. 
(Original No. 50.) 

Geographic (listribution. — Soutliern Alabama and adjacent part of 
northwest Florida, witiiin the Austroriparian zone (map 4). 

General characters. — Similar to G. tuza, but somewhat smaller, aud 
much darker in color; tail shorter, nearly naked; feet scant haired. 

Color. — Upper parts dark, generally sepia or bistre, washed on sides 
of face and body with golden brown or ochraceons, intimately mixed 
with black-tipped hairs; top of head, between eyes and including ears, 
dusky, with an ill-delined dorsal band of the same jolor. Under parts 
dark plumbeous, faintly Avashed with dull pale fulvous. Hairs of feet 
whitish. More or less white about throat and pouches. 

Cranial charactcrs.-^SkuW very long aud angular (pi. 7, lig. 2); fron- 
tal broad aud high; top of skull in profile strongly convex; isygomatic 
arches broadly spreading, divergent anteriorly, and angular; brain 
case broad and tlat; palatopterygoids narrow, their sides parallel; 
temporal impressions in adult males meeting in a low but well-developed 
sagittal ridge; interparietal deeply excavated posteriorly (trousers- 
shaped), reduced in advanced age by meeting of temporal ridges (fig. 
6, /and g). G. mobilensis differs from G. tuza in the great breadth of 
the frontal interorbitally; the narrow palatopterygoids; the presence 
of a sagittal ridge in adult males, and the very different shape of the 
interpariteal (fig. G). It differs from florid anus in much smaller audita! 
bulkv, broader frontal, lower and more depressed brain case, more 
divergent zygomatic arches, narrower ascending branches of premax- 
illa and much narrower palatopterygoids. G. mobilensis differs from 
G. brcrieejys^ its nearest neighbor on the west, in general form of the 
skull and in numerous details : in profile the top of the skull is strongly 
convex instead of concave; the zygomatic arches are more angular and 
more divergent anteriorly; the frontal is nnich broader interorbit- 
allj'-; the brain case flatter; the nasal bones broader and constricted in 
front of the middle; the angular process of the mandible deeply notched 

Measurements (taken in flesh). — Ty2)e specimen: Total length, 2G0; 
tail vertebrae, 82 ; hind foot, 33. 


Aiwrage of four males from type locality: Total length, 250; tail 
vertebr;e 81 ; liind foot, 33.5. 

Avcrmje of four females from same place: Total length, 229; tail 
vertebrae, 7(!; hind foot, 30.5, 

For'crauial measurements see Table 0, p. 208. 

Specimens examined. — Total number 23 : 9 from Point Clear, Mobile 
Bay, Alabama, 2 from Brewton, Alabama, and 12 from Milton, Florida. 

General remarks. — Geoniys mobilensis is an inhabitant of the low- 
lands bordering the Gulf of Mexico east of Mobile Bay. How far its 
range extends to the east and north has not been ascertained. In size 
and coloration it seems to bear the same relation to its neighbor {G. 
tuza) of the adjacent pine barrens of Georgia that G. hrericeps of the 
lowlands of Louisiana and Texas bears to its relative of the higher and 
drier ground further west {G. lutescens). 

It seems a pity that such a strikingly marked animal as mobilensis 
must stand as a subspecies, but there is no reasonable doubt of its 
complete iutergradation with tuza in western Georgia. 


(Pl.l; pi. 9, figs. 8 and 9; pi. 10, fig. 6; pi. 13, fig. 11; pi. 14, fig. 2; pi. 15, fig. 11; pi. 
17, fig. 3; pi. 18, fig. 1; pi. 19, fig. 3; text fig. 55.) 

Mhs hursariiis 8haw, Trans. Linnean Soc, v. 1800, 227-228, pi. 8; Genl. Zoology, 

Mammalia, Vol. ii, pt. 1., 1801, 100-101, pi. 138. 
? Miis hidovicianus Ord. Guthrie's Geography, 2d Am. ed., 1815,292 (Nomen nudiDn). 
BipJostomafusva Rafinesqiie, Am. Monthly Magazine, Vol. ii, No. i, Nov. 1817, 45. 
Geomys ci neren Rafincsqne, Am. Monthly Magazine, Vol. ii, 1817, 45. {Miis I) ur sarins 

Saccophorus hiiysarius Kuhl, Beitriige ziir. ZooL, 1820, 65. 
MnssaccalHs Mitchill, New York Medical Repository, Vol. vi, n. s., 1821, 249. (Type 

from Lake Superior, probably Minnesota.) 
Psendostoma biirsariKS Say, Long's Expd. to Rocky Mts., i, 1823, 406. 
Asromi/s caxadensis hicht., Abh. Akad. Wiss. Berlin (1822), 1825, 20, fig. 2. 
Geomijs'/ biirsariiis Richardson, Fauna Boreali-Americana, i, 1859, 203. 
Geomys canadensis LeConte, Proc. Acad. Nat. Sci., Phila., vi, 1852, 158. 
Geomys orcfionensis LeConte, Proc. Acad. Nat. Sci., Phila., vi, 1852, 160. (Locality 


Type locality . — Unknown; somewhere in Upper Mississippi Valley. 

Geographic distribution. — Upper Mississippi Valley from a short dis- 
tance south of the Canadian boundary, in longitude 97° (Warren, Min- 
nesota, and Grand Forks, North Dakota), southward to eastern Kan- 
sas (Neosho Falls), southeastern Missouri (Williamsville and Hunter), 
and southern Illinois (Belleville); east nearly to Lake Michigan (Win- 
nebago and Fond du Lac, Wisconsin, and Cook County, Illinois); 
west in the Dakotas and Nebraska to the ninety-eighth or ninety- 
ninth meridian (Valley City and Hamlin, North Dakota; Burch, 
Mitchel, and Scotland, South Dakota; Niobrara, Ericson, and Kearney, 
Nebraska). The species belongs to the Upper Sonoran and Transition 
zones. See map 4, b. 


General characters. — Size large; coloration dark; tail raedium or 
rather long, scant haired, the terminal half nearly naked. 

Color. — Dark liver brown or chestnnt above and beloAv, somewhat 
[)aler on the belly (belly very rarely whitish); fore feet white; hind feet 
soiled white; hairs of tail usually brown on basal part and white on 
terminal part. 

Cranial characters. — Skull long, large, and angular (pi. 1); zygomata 
spreading, widely divergent anteriorly, angular; a well -developed 
sagittal crest; rostrum long and narrow for size of skull; frontal nar- 
row and rounded interorbitally; palatoptery golds broadly Ungulate, 
tapering posteriorly, not notched at base on outer side (pi. 14, fig. 2). 
The skull of G. hursarins does not require close comparison with any 
other species, though the young and females are sometimes difticult to 
distinguish from lutescens. The skull of the female differs from that 
ot the male in much smaller size, shorter rostrum, broader interorbital 
region, fuller brain case, in the absence of distinct sagittal and lamb- 
doidal crests, and in the less development of processes and ridges for 
nuiscular attachment. Skulls of G. bursarius differ from those of lutes- 
cens chiefly in greater length and angularity, the ratio of zygomatic 
breadth to basilar lentli of Hensel rarelj'' exceeding 73 percent in 
adults; while in I ntesceiis this, ratio runs from 75 to 79. The brain 
case is higher posteriorly and the sagittal crest is much more highly 
developed. G. hnrsarius (in common with lutescens) differs from per- 
sonatus notably in the angle of the anterior part of the zygomatic arch 
and in the length of the Jugal. In both bursarius and lutescens, even 
in old age, the anterior root of the zygoma slopes back at a consider- 
able angle; in personatus it stands ont at nearly a right angle. In 
bursarius and lutescens the Jugal is much longer than the basioccipital ; 
in personatus it only equals the basioccipital. 

Dental cliaravters. — Face of upper incisors strongly bisulcate; small 
sulcus fine and close to inner edge of tooth ; principal sulcus much 
larger and on or slightly external to median line; enamel face rounded 
externally and between sulci (fig. 22^, and pi. 15, fig. 11). Molariform 
teeth much smaller than in the other sections of the genus; crown of 
last upper molar suborbicnlar, without heel. 

Upper molariform series. — The upper premolar curves and slopes 
strongly forward and is concave anteriorly; the last molar curves 
strongly backward and is concave posteriorly. The intermediate molars 
curve both backward and outward; the first only slightly backward, 
the second strongly; both are concave externally; their roots divari- 
cate, the first sloping forward, the second backward. (A second and 
greater point of divergence is between the premolar and first molar.) 
Tlie ])remolar is nearly one-third longer than the last molar. The inter- 
mediate teeth are about as long as the premolar — sometimes longer. 

Lower molariform series. — All the teeth are short compared with those 
of the upper series; premolar longest, largest, heaviest, and curves 



[no. 8. 

strouffly forward; last molar smallest, shortest, and curves strongly 
backward; the intermediate teeth intermediate in length* Premolar 
strongly concave anteriorly and nearly as concave ontward ; nij slightly 
concave anteriorly, strongly concave outward, and somewhat twisted 
on its axis; nij strongly concave outward and faintly anteriorly, with 
a slight twist; nis strongly concave posteriorly and moderately so out- 

Average measurements of 26 specimens of both sexes from eastern 
North Dakota (measured by J. Alden Loring) : Total, 270; tail vertebriie 
80; hind foot, 35. Average of C males from same localities: Total, 21)0; 
tail vertebrae, 90; hind foot, 37. Average of 10 females: Total, 2G5; 
tail vertebra^ 78; hind foot, 34. Average total length of 20 males and 
20 females from Elk Eiver, Minnesota, measured in tlesh by Vernon 
Bailey : Males, 284; females, 243. In both cases many of the specimens . 
are not full grown, hence the measurements are toe small. Unfortu- 
nately no satisfactory series of measurements is available.* 

For cranial measurements see Table A, p. 204. 

General remarls. — Geomys Jmrsarhis is a well-marked species, easily 
distinguishable by color alone from all the, other bisuicate forms. It is 
also the largest species inhabiting the United States, although varying 
considerably in size in different localities. The largest form inhabits 
the region about Knoxville, Iowa, where the males average a foot in 

Geomys hursarius is of much greater economic consequence than all 
the other species combined, for the reason that its home is in the fertile 
prairie region of the Mississippi Valley from central Missouri northward, 
covering the whole State of Iowa, nearly the whole of Illinois, and the 
richest and most densely populated agricultural lands of eastern Kan- 
sas, eastern Nebraska, eastern South and North Dakota, Minnesota, 
and southern Wisconsin. 

Specimens examined. — Total number 116, from the following localities: 

North Dakota: Portland, 18; Erie, 3; Oasselton,2; Buflalo, 2; Valley 
City, 3. 

*Dr. C. E. McChesney, U. S. Army, iu a paper on the Mammals of Fort Sisseton, 
Daliota, has recorded a valuable series of measurements of this species, all taken at 
that locality. While his measurements are not strictly commensurate with ours, and 
while many of his specimens were not full grown, his means are important, particu- 
larly as showing the average sexual diiference. Reduced to millimeters his most 
important means are : 

Mea,n of— 

Tliirty-tliree males, Fort Si.sset.on, South Dakota 
TJiirty five female.s, Fort Si.s.setoii, South Dakota 
Sixty-oight specimeu.s, both sexe.s 

Head and 

Tail ver- 
tebrai . 







(Bull. U. S. Geol. andGeog. Survey, Terr, iv, No. 1, Feb., 1878, p. 213.) 


Soiitb. Dakota: Flandreau, 1; Fort Sissetou, 1; Travare, 2; Scot- 
land, 1. 

Minnesota: Ortouville, 2; Browns Valley, 1; Elk River, 39. 

Iowa: Council Bluffs, 1; Kuoxville, 16. 

J^ebraska: Xiobrara, 3; Verdigris,!; Columbus, 1; Ames,!; Blair, 
1; Norfolk, 2. 

Kansas: Onaga, 3. 

Missouri: Hunter, Carter County, 4; Williamsville, Wayne 
County, 8. 


The early history of this gopher is somewhat obscure. It was origi- 
nally described by Shaw m the year 1800 and was named Mm bursa 
rins. * The description is very brief and is as follows : " Ash-coloured 
rat, with short round nearly naked tail, pouched cheeks, and the claws 
of the forefeet very large, formed for burrowing in the ground." Shaw 
states further: " This quadruped was taken by some Indian hunters in 
the upper parts of interior Canada, and sent down to Quebec. It is 
now in the possession of Governor Prescot." The description is accom- 
panied by a full-size engraving of the animal, with cheek pouches 
turned inside out and distended. The skin evidently was greatly 
overstuffed. No grooves are shown on the upper incisors. 

The next year (1801) Shaw redescribed the same specimen as follows: 
" It is about the size of a brown or Norway rat, and is of a pale greyish- 
brown colour, rather lighter beneath; the length to the tail is about 9 
inches, and that of the tail, which is but slightly covered with hair, 
about 2 inches: the legs are short; the fore feet strong, and well adapted 
fov burrowing in the ground, having five claws, of which the three mid- 
dle ones are very large and long; the interior much smaller, and the 
exterior very small, with a large tubercle or elbow beneath it. Tlie 
claws on the hind feet are comparatively very small, but the two mid- 
dle are larger than the rest, and the interior one is scarce visible: the 
teeth are extremely strong, particularly the lower i)air, which are much 
longer than the upper: the ears are very small." (General Zoology, 
vol. IT, part 1, Mammalia, 1801, pp. 100-101.) He gave a new engrav- 
ing of the animal, stating that in the figure previously published (in 
the Transactions of the Linneau Society) "the claws on the fore feet 
are represented as only three in number, and are somewhat too long, 
weak, and curved. The engraving in the present plate is a more faith- 
ful representation, and is accompanied by an outline of the head, in its 
natural size, as viewed in front, in order to shew the teeth and cheek- 
IKHU'lies." This plate contains three figures: a side view, as in the 
earlier engraving; a front view, reduced, and a natural-size front view 
in outline. The cheek pouches are everted, as before, jirotruding from 

"Transactions of the Linnean Society, London, vol. V, 1800, pp. 227-228; descrip- 
tion read before the society June 4, 1799. 


the sides of the face as great bursie. Although the teeth are distinctly 
shown in these engravings, no trace of a groove is apparent, unless an 
incomplete dotted line near the middle of each upper incisor in the out- 
line figure was intended to indicate it. The size of the incisors in this 
figure agrees exactly with the size of these teeth in specimens of Tho- 
momys talpoides from Manitoba, and the size and shape of the fore feet 
and claws are as in Thotnomi/s, thus dittering widely from the same 
parts in Geomys, in which the teeth and claws are very much larger and 

The color of the body (which he describes as " pale greyish-brown, 
rather lighter beneath "), the size and shape of the forefeet and claws, 
the size of the incisors, the absence of the deep median furrow so con- 
spicuous in Geomys (which could hardly have been overlooked both in 
the description and figure), together with the statement that the animal 
came from the interior of Canada, all indicate that the species now 
known as Thomomys talpoides was the animal Shaw had before him. 

The only point mentioned by Shaw in either of his descriptions of 
the type specimen of ^ Mus hursarim^ that does not apply strictly to 
Thomomys, to the exclusion of Geomys, is the length of the animal, 
which he gives as 9 inches. This is easily explained on turning to the 
figure, which shows the specimen to be greatly overstuffed— a common 
error in taxidermy resulting from the exceedingly loose and distensible 
skins of these animals, which are nearly always stretched in taking off 
from the body. 

Eecapitulating, Shaw's description and figures seem to establish the 
following points: 

(1) The type specimen of 31us bursarius came from the "upper parts 
of interior Canada," the home of Thomomys. No member of the genus 
Geomys reaches Canada, its northernmost known point being Warren, 

(2) The type specimen of i¥<6s bursarius was "ash coloured" or "pale 
greyish-brown, rather lighter beneath," exactly as in Thomomys. The 
color of the only species of Geomys inhabiting the Upper Mississippi 
Valley is dark chestnut or liver-brown, both above and beloAv. 

(3) The detailed description given by Shaw in his General Zoology 
makes no mention of grooves in the incisors, though these teeth are 
described with particularity. In Geomys the upper incisors are deeply 
furrowed; in Thomomys they are plane. 

(4) Not one of the four figures of the type specimen of Mus bursa- 
rius published by Shaw shows any trace of the grooved incisors of 
Geomys, and two of these figures are front views, one natural size. 

(5) The size of the teeth, fore feet, and claws in Shaw's natural-size 
figure agree with these parts in Manitoba specimens of Thomomys and 
are very much smaller than in Geomys. 

From the above facts it would appear that the animal described by 
Shaw under the nameilf«.s- bursarius is the gray pocket gopher of Man- 


itoba aucl the Dakotas {Thomomys talpoides of recent authors) aud not 
the red pocket gopher of the Mississippi Valley ( Geomys bursarius of 
recent authors). This view would necessitate a slight change in nomen- 
clature: Tli<)m(>)iiys taljwides Auct. would become Thomomys bursarius 
(Shaw), aud Geomys bursarius Auct. would become either Geomys fuscus 
(Eafinesque) 1817, or Geomys sacc((fus (Mitchill) 1821.* Fortunately no 
change in the generic name would be required, since Kafinesque based 
his genuL,> Geomys on G.pinetis [=■ G. tuza] of the pine barrens of Georgia. 

Clear as the case seems to have been left by Shaw, it became shrouded 
in obscurity by the writings of subsequent authors. 

In 1820 Heinrich Kuhl published his Beitriige zur Zoologie, in which 
he described the genus Saccophorus, basing it on the Mus bursaritts of 
Shaw. lie states that the specimen examined by him was formerly 
in Bullock's Museum, but then in Paris (''in Museo Bullokiano, nunc 
Parisieiisi," p. 6.")), but does not intimate that it was Shaw's specimen. 
In the diagnosis of the genus he states that the upper incisors have 
two sulci, of which the external is broader and deeper, thus describing 
the condition in typical Geomys. 

Lichtenstein, in a paper written in 1822, but not published until 1825, 
says: '• When I was in London in the summer of 1819 I saw in the 
Bullock collection the specimen described by Shaw" (UberiiussereBack- 
entaschen an Nagethiereii, Abh. K. Akad. Wiss. Berlin [for 1822], 1825, 
14-15). He then goes on to describe another specimen, assumed to 
belong to the same species, which he says he had recently received 
from North America. 

The iirst positive statement I have been able to find to the eftect that 
Shaw's specimen had grooved incisors was made by liichardson more 
than a cpiarter of a century after the publication of Shaw's last descrip- 
tion. Richardson states that the engraving of Shaw's Mus bursarius 
published in the Linnean Transactions was drawn by MaJ. Davies,t 
and that ''the specimen figured by Major Davies, in the Linnean Trans- 
actions, was of a pale gray colour, and 9i inches long from the nose to 
the root of the tail, which measured 2i inches. The belly was ])aler 
than the back, and the cheek-pouches were covered with very short 
pale hairs. Its superior incisors were deeply grooved in the middle, 
aud more faintly close to their inner margins" {Ibid., 203). As to the 
final disposition of this specimen he says: "The identical specimen 

* Diplostoma fitsca Kafinesque, Am. Monthly Mag. ii, 1817, 45, is little more than 
a noiiien nudum, the only specific description being "entirely brown, length 12 
inches." But the generic (, though full of errors, leaves no doubt as to the 
animal; aud the locality assigned, "Missouri Territory," is sufficiently exact in con- 
nection with the size and color of the species. If, however, this name is not con- 
sidered available, the next in point of date seems to be Mus saccaius Mitchill, Medi- 
cal Repository, vol. vi, 1821, 248-250; type "from the region bordering on Lake 
Superior," doubtless Minnesota, where the animal is abundant. The bisulcate upper 
incisors are described in detail by Mitchill. 

t Fau^ia Boreuli- Americana, 1829, 199. 


described by Shaw, * * * on the dispersion of Mr. Bullock's col- 
lection, passed into the hands of M. Teniniinck" {Ibid., p. 199). 

That this x^ai'ticular specimen is now in the Leiden Museum is 
certain, for it is mentioned by Dr. F. A. Jentink, the able director of 
the Eijks Museum, in his Catalogue Systematique des Mammiferes, xii, 
1888, J). 93. In response to a letter of inquiry. Dr. Jentink has had 
the kindness to write me as follows: "On the underside of the stand 
[of the si)ecimeii above mentioned] I see the following words written 
with pencil: 'Mus bursarius, Cabinet Bullock, Londres.' So you may 
be sure of the fact that this specimen truly has been bought from Bul- 
lock's auction. As to the animal itself and its identity with Shaw's 
description, you may judge if 1 tell yoTi that it has the cheek pouches 
turned inside out and distended, but not in the extraordinary way as 
represented in Shaw's figure 138, vol. ii, p. 1. The incisors are deeply 
grooved. Shaw's figure represents, without doubt, an overstuffed speci- 
men; meanwhile our specimen seems to be in excellent proportions and 
very well-preserved condition. Length of the animal, 9.8 inches, meas- 
ured from the upi3er lip along the dorsal line of the l)ody ; tail about 
2.8 inches. The color of our specimen is a desert color, more reddish 
toward head and hinder j)arts of the body." 

In 1857 Baird made the following statement, evidently based partly 
on the remarks of Richardson, already quoted, and partly on an erro- 
neous translation of the statements of Kuhl and Lichtenstein. Baird 
says: '-The same skin referred to by Shaw was subsequently investi- 
gated by Kuhl, and then by Lichtenstein. It was for a time in the 
celebrated museum of Mi-. Bullock, of London, and is said to have 
been purchased by Temminck at the sale of this collection, and is doubt- 
less now in the Leyden Museum." (Mammals of North America, 1857, 
370.) But Kuhl does not say that his specimen was the same as Shaw's, 
and Lichtenstein distinctly states that the animal described by him was 
not Shaw's specimen (which he says he saw in London in 1819), but one 
that he " received a short time ago with other North American mam- 

If it is true that the specimen described by Kuhl is really the same as 
that described by Shaw twenty years earlier, and afterwards mentioned 
by Lichtenstein as having been seen by him in London in 1819, it would 
be certain that no other animal thfin the furrowed-toothed pocket gopher 
of the Upper Mississippi Valley {Geomy.s) could be meant. But unfor- 
tunately Kuhl says nothing on this point, and it must be admitted that 
the conspicuous discrepancies between his description and Shaw's are 
hard to reconcile on the assumption that they refer to the same speci- 
men. Sliaw says the body (jf his animal as stuffed measured 9 inches, 
and the tail 2 inches. Kuhl says the body measured 7^ inches, and tail 
2^ inches. Shaw described his animal as "ash-coloured," and "pale 
greyish-brown," while Kuhl says that his inclined to rufous ("rufes- 
cens ") — the proper color for Oeomys. 


Is it not i)0ssible that Uicbiu'dsoii, in translating" the Latin of Knbl 
or the (Jerman of Lichtenstein, fell into the same error as Baird? At 
all events it .should not be forgotten that liichardsoii wrote nearly 
thirty years later than Shaw — an interval sufficiently long -to allow 
additional specimens to reach England and also to favor slips of mem- 
ory. It should be further remembered not only that Lichtenstein had 
a specimen additional to that described by kShaw, but also (and much 
more important) that there a])j)ears to be no ground for the assump- 
tion that Kuhl's description was taken from Shaw's specimen; in fact 
the marked discrepancies between them seem to jirove the contrary, as 
pointed out above. 

Shaw\s and Richardson's descriptions are utt^irly irreconcilable on 
the assumption that they refer to the same specimen, but would be per- 
fectly intelligible if it can be shown that a second specimen found its 
way into the Bullock collection between the years 1800 and 1819. 

The matter is still further complicated by Richardson himself, who, 
writing in 1831, says: " We lately received several specimens of the 
Mus burftai'liis of Shaw (which is a true Gcomys^ with pouches oiiening 
internally) from the banks of the Saskatchewan." (Zoology of Beechey's 
Voyage of the Blossom, 1839, 9,) This statement shows that Richard- 
son's ideas respecting- the status and distribution of the several mem- 
bers of the group were badly confused, for it is now well known (as 
before stated) that no species of Geomys reaches the plains of the Sas- 
katchewan ; indeed the genus has not been found to enter Canada at 
all. The use of the generic name Geomys by Richardson, however, has 
no significance, since he applied the name to Thomomys as well as 
Geomys^ and it is certain that his Saskatchewan animal is Thomomys 
talpoides Auct. His identification of the species with Mus bursarius 
of Shaw would be in accord with my belief that Shaw's animal could 
have been no other than the common Thomomys of Manitoba and the 
northern plains generally, except for his previous statement, already 
quoted from Fauna Boreali-Americana, that the Bullock specimen had 
grooved incisors and was the identical specimen described by Shaw. 
These conflicting statements by the same author I am utterly unable 
to reconcile. 

(PL 9, figs. 5 and 7; pi. 14, fig. 14.) 
GeomyKburmrins lutescens Merriam, N. Am. Fauna, No. 4, Oct. 8, 1890, .51. 

Tyjye locality. — Sand hills on Biedwood Creek, Lincoln County, 
Western Nebraska. (Type in U. S. National Museum.) 

Geoymphic distribution.— The Upper Sonoran belt of the Great Plains 
from southwestern South Dakota southward to Colorado, Texas, cover- 
ing the sand-hill region of western Nebraska, extreme eastern Wyom- 
ing (between the North Platte and Cheyenne rivers) western Kansas^ 


■eastern Colorado, western Oklahoma, and western Texas, ranging east 
to or a little beyond the ninety-ninth meridian (map 4, C). 

General characters. — Size medium or rather large; coloration jjale; 
tail moderate; scant haired; skull short. 

Color, — Upper parts in winter drab, liberally mixed with black-tip- 
ped hairs along the median line, forming a distinct dorsal band from 
end of nose to rump; in summer pale buffy-ochraceous or very pale dull 
fnlvons without dorsal band. Under parts buffy, usually white in the 
young and sometimes white in adults. Along the eastern and south- 
ern limits of its range the upper parts are decidedly more fulvous than 
in the typical animal. 

Cranial characters. — Skull intermediate in size between hrerlceps and 
bursarius; zygomata broadly and squarely spreading, strongly diver- 
gent anteriorly; nasals normally elongate w^edge-shaped, as in hursarius, 
but sometimes broadening in posterior third ; tem])oral impressions nor- 
mally uniting, at least posteriorly, in a low sagittal ridge (pi. 9, tig. 7), 
but sometimes remaining apart, separated by an interspace 1 to 3 mm. 
broad (pi. 9, tig. 5) [this form is connnonest in the southwestern part of 
the range of the species] ; interparietal varying from subquadrate in 
the young to subtriaugular in adults, its size decreasing with age and 
the posterior suture becoming obliterated by ankylosis with the supra- 
occipital; palatoi)tery golds usually lingniate and tapering posteriorly 
as in hvrsarins, but somewhat narrower and sometimes strap-shaped. 

Skulls of Geomys late^scens differ from those of G. hursarius chiefly in 
smaller size, greater relative breadth and flatness (the braincase as well 
as the rostrum being considerably shorter than in true hursarins from the 
Mississippi Valley), and in lacking the high sagittal crest of hursarius. 
Old skulls of lutcsccns have strongly spreading zygomatic arches which 
are very much broader anteriorly than posteriorly, and as a rule the 
premaxilla extends a little further back than in hursarius. 

Sknlls of lutrscens bear a strong resemblance to those of breviceps, 
from wdiich they difl'er in having the frontal region less depressed; the 
zygomatic arches more squarely spreading and more decidedly angular 
anteriorly; the nasal Ijones broader posteriorly; the ascending branches 
of the premaxilla longer and less blouutly rounded posteriorly; the 
temporal impressions normally meeting posteriorly in a low sagittal 
ridge instead of remaining distant; the occiput more truncate (less 
bulging) j)osteriorly ; the rostrum normally broader. 

The cranial characters that distinguish lutescens from texensis, aren- 
arius, und 2)er so nat us are mentioned under tbe heads of these species. 

Measurements. — Average of 28 specimens of both sexes from western 
Nebraska: Total length, 256; tail vertebrae, 77; hind foot, 32. Aver- 
age of 12 males: Total length, 270.5; tail vertebr;e, 84; hind foot, 33.5. 
Average of 10 females: Total length, 210; tail vertebrae, 72; hind foot, 

For cranial measurements, see Table A, p. 204. 


Specimens examined. — Total number of tyj)icalor nearly tyj)ical speci- 
mens 118, from the following localities: 

South Dakota: Pine Ridge Agency, 2; llosebud Agency, 3. 

Il^ebraska: Chadron, 1; Kennedy, ISj Valentine, 3; E wing, 2; Oak- 
dale, 2; Crawford, 1 ; Snake River, Cherry County, 1; Chirks Canyon, 
Cherry County, 7; Dismal River, Thomas County, 1; Xiobrara River, 
Sheridan County, 1; near North Platte, Lincoln County, 4; Birdwood 
Creek, 1; Myrtle, 3; Sidney, 1; Calloway. 4- Kearney, 1. 

Wyoming: Lusk, 3; Uva, 1. 

Colorado: Las Animas, G; Denver, 1; Pueblo, 4 j Limon, 3; Burling- 
ton,!; Chivington, G. 

Kansas: Trego County, 3. 

Oklahoma: Woodward, 3. 

Texas: Canadian, 5; Tascosa, 4; Newlin, 3; Childress, 12; Vernon, 
9; Colorado, 3. 

Number of non-typical specimens 18, from the following localities: 

Kansas: Garden Plain, 4; Belle Plain, 5; Cairo, 6; Kiowa, 2; Ellis,!. 

General remarks. — Geomys lutescens is a pallid species inhabiting the 
arid plains west of the ninety-ninth meridian. Its characters are very 
constant throughout most of its range, and if it intergrades with bur- 
sariiis it must do so in the narrow strip between the ninety-eighth and 
ninety-ninth meridians. In southeastern Kansas an aberrant form 
exists that seems to be an intergrade between the three types, hursarius, 
lutescens and brevicepSj but a larger series of specimens than at present 
available is needed to prove it. This animal is smaller than httescens, 
nearly as dark above as hursarius, and paler below than either. Some 
specimens indeed have the belly pure white, as in texensis. Specimens 
of this ajiparently intermediate form (mostly immature) have been 
examined from Cairo, Kiowa, Garden Plain, and Belle Plain, Kansas. 

Mr. Vernon Bailey states that in western Nebraska, where typical 
lutescens is abundant, the light sandy soil is probably improved by their 
diggings, but that they do considerable damage in grain fields and to 
young trees on the tree claims. 

(PI. 9, fig. 6.) 
Geomys hrevxceps Baiid, Proc. Acad. Nat. Sci. Phila., vii, April, 1855,335. 

Type locality. — Prairie Mer Rouge, Morehouse Parish, 

Geographic distribution. — The alluvial lowlands of the Mississippi 
Valley and Gulf coast in southern Arkansas, Louisiana, and Texas, and 
the valley of the Arkansas River; north nearly to southern Kansas, 
and west to near the ninety-eighth meridian, where it is replaced by G. 
lutescens. It is therefore a memberof the Austroriparian fauna (maplD). 

General characters. — Size small; color very dark both above and 
below; tail of medium length, its distal half nearly naked. 
7433^.^No. 8 9 


Color. — Upper parts dark russet brown, darkest along the middle of 
the back (but no trace of dorsal band in Louisiana specimens) ; nose 
and front of face to above eyes dusky, more or less tinged with rus.^et; 
sides Avashed with pale fulvous; belly dark plumbeous, more or less 
obscured by pale bufify-fulvous tips to the hairs; feet and throat white; 
hairs on base of tail dusky (remainder of tail practically naked). The 
color of the back is hard to describe, aud the term used (' russet-brown ') 
is intended only as roughly indicating the general effect. The indi- 
vidual hairs are dark plumbeous, with a narrow subapical zone of dark 
fulvous, tipped with sooty. 

Cranial characters. — Skull similar to G. lutescens in general appear, 
ance but smaller; zygomata broadly s[)roading; frontal flat, depressed; 
nasals narrow, emarginate posteriorly, their sides nearly parallel for 
posterior two-tliirds, abruptly divergent anteriorly : ascending branches 
of premaxilla broad and bluntly rounded posteriorly; interparietal 
small, very irregular, and much cut up with tortuous windings of the 
sutures as in true 'Wormian' bones; temporal impressions never 
uniting in a sagittal crest but permanently distant, the interspace 
elevated, forming abroad convex band (3 to 5 mm. in width) along the 
top of the skull posteriori}-; jugal longer than basioccipital, bluntly 
rounded anteriorly; occiput bulging behind lambdoid suture, but not 
so far as in fcxensis; i)tery golds narrow, tapering posteriorly. 

Skulls of ?;>Tr/c('j9.S' may be distinguished from those of lutescens by 
the following characters (pi. 9, fig. G) : Size smaller; nasals narrower, 
shorter, and strongly emarginate posteriorly; ascending branches of 
premaxilla normally shorter and more bluntly rounded iwsteriorly; 
temporal impressions persistent, distant, the bone thickened between 
them; iaterparietal 'Wormian 'like; zygomata more rounded; inter- 
orbital region more depressed. Nevertheless, the cranial resemblances 
are striking in view of the dissimilarity of the animals in size aud 
external appearance. Moreover, skulls of hreviceps from the western 
part of its range have broader nasals ; and skulls of lutescens from adja- 
cent territory have a narrow sagittal area (resulting from permanently 
distant temporal impressions). It is probable, therefore, that the two 
forms will be found to intergrade. 

Skulls of hreviceps differ from those of texensis in larger size, much 
more spreading zygomata; longer and very much narrower nasals; 
broader, flatter, and more depressed frontal interorbitally; much longer 
jugal; smaller and more irregular interparietal; less bulging occiput; 
broader and more bluntly rounded ends to ascending branches of pre- 
maxdla. Viewed in profile, the skull of^hrericeps is flat and somewhat 
depressed or concave between the orbits; that of texensis is normally 

Average measurements of -40 specimens of both sexes from type locality 
(Mer Rouge, Louisiana): Total length, 219; tail vertebra^, 64; hind 
foot, 27. Average of 15 males from same place: Total length, 231; tail 



vertebrae, 70; hind foot, 28. Average of 23 females from same place: 
Total leugtli 212; tail vertebra, (51; hind foot, 2G.5. 

For cranial measurements see Table A, p. 205. 

General remarhs. — Tlie type form of Geoniys hreviceps inhabits 
northern Louisiana, east of the Red River, the exact type locality 
being" Prairie Mer Rouge in Morehouse Parish, near the northern 
boundary of the State and only a short distance west of the Mississippi 
River. The species as a Avhole is an inhabitant of the dark alluvial 
soils of the lowlands bordering the Lower Mississippi and its tributa- 
ries and the Gulf coast of Texas, whence it spreads westward nearly or 
quite to the ninety-eighth meridian. To the southward it reaches 
Nueces Bay. On the west it probably iutergrades with texensis and 
lutescens. On the north there seems to be a hiatus between its range 
and that of bursar ins; but if pocket gophers are ever found in northern 
Arkansas, southwestern Missouri, southeastern Kansas, or north- 
eastern Indian Territory, they are likely to prove intergrades. 

Departures from the type. — Specimens from extreme points in the 
range of the species differ much from the type. Two of these forms 
are here named as subspecies {G. hreviceps sagittalis and G. hreviceps 
atticateri). Others are regarded as slightly aberrant forms not merit- 
ing recognition by name; others still as intergrades. The following, 
contained in the Department of Agriculture collection, seem worthy of 
mention : 

(1) A large dark form inhabiting the valley of the Arkansas River. 
The skulls point toward intergradation with the interior animal. 
Specimens from Tulsa and Fort Gibson, Indian Territory, and Fort 
Smith, Arkansas, resemble hreviceps in coloration, while those from 
Pouca Agency, Indian Territory, are redder, shading strongly toward 

(2) A form from the valley of the Red River of the South, along the 
boundary between Texas and Indian Territory (specimens from Gaines- 
ville, Tex., and from Indian Territory opposite Arthur, Tex.). A small 
reddish form resembling hreviceps externally, but with dark belly and 
a short tail. The skulls are more like texensis in general form (full 
brain case and narrow zygomata), and in the shortness and breadth 
of the nasals; but the ascending arms of the premaxilla are even 
shorter and more bluntly rounded posteriorly than in hreviceps. The 
frontal and interparietal are intermediate between the two,* Regarded 
as an intergrade. 

(3) A form from Slireveport, Louisiana. Much redder than true 
oreviceps, resembling texensis in coloration of upper parts, but with 
dark beily. The skull differs from typical hreviceps in more angular 
zygomata, broader nasals, and less depressed frontal. Regarded as a 
slight local departure from hreviceps. 

* Skull No. 47590 <? ad. from Gainesville, Texas, is an excellent example of this 


[NO. 8. 

(4) A foi'iii fVoiu Galvestou Bay, Texas (specimens from Clear Creek 
abd Arcadia), A small, dark, llighly-colored form with the head nearly 
black, and the throat and fore feet ilsnally Avholly or partly white, in 
sharj) contrast with the dark of the surrounding parts. The skull differs 
from that of typical brevic&ps in smaller size, and in having shorter and 
broader nasals, llegarded as a subspecies and described under the 
name mgittalis. (PI. 9, fig. 4.) 

(5) A fbt'm from thft Coastal plane of Texas (si)ecimens from Brenham, 
Milano, Hearne, Marquez, and Palestine.) Usually has a well-marked 
dark dorsal band, and the skulls differ from typical hreviceps in having 
shorter and broader liasals. Skulls of old males from these localities 
are unusually short and have broadly spreading zygomata. The nasals 
are very broad posteriorly in comparison with true hreviceps. Eegarded 
as an aberrant form, perhaps shading toward texensis on one side and 
toward atticateri and saf/ittalh on the other. 

(()) A form from the extreme southern limit of the range of the spe- 
cies on and near the Gulf coast of Texas, (Specimens from Eockport, 
Aransas County; Tallj^s Island, Aransas County, and near San 
Antonio.) A large dark form with a dark dorsal band in some pelages, 
and peculiar cranial characters: angular and strongly divergent zygo- 
mata, very broad ascending arms of premaxilla, and so on. Eegarded 
as a subspecies, and described under the name attwateri (pi. 9, fig. 3). 

Specimens examined,— Total number, 274, from the following locali- 
ties : 

Typical or nearly typical. — Mer Eouge, Morehouse Parish, Louisiana 
(type locality), 42; Pineville, Eapides Parish, Louisiana, 2; Provencal, 
Natchitoches Parish, Louisiana, 4 ; Shreveport, Caddo Parish, Louisi- 
ana, 8; Camden, Ouachita County, Arkansas, 1; Benton, Arkansas, 7; 
Fort Smith, Arkansas, 7; Fort Gibson, Indian Territory, 16; Tulsa, 
Indian Territory, 2. 

Not typical. — Gainesville, Cook County, Texas, 5; Decatur, Texas, 
1; Indian Territory, near mouth of Boggy Eiver (opposite Arthur, 
Texas), 4; Pouca xVgency, Oklahoma, 0; Oklahoma City, Oklahoma, 3. 
The following, all from Texas: Longview, 4; Mineola, 14; Terrell, 7; 
Troup, 1; Palestine, 5; Marquez, 5; Hearne, 9; Milano, 12; Brenham, 7; 
Victoria, 1; Inez, 3; Navidad Eiver, 1; Houston, 9; Matagorda Bay, 9. 

Subspecies sagittal is. — INIouth of Clear Creek, Galveston Bay, 4; 
Arcadia, Galveston Bay, 22. 

Snbsjwcies atticateri. — Eockport, Aransas County, 40; Tallys Island, 
Aransas County, 3; Calaveras, Wilson County, 3; San Antonio (18 
miles south), Bexar County, 7. 

Mr. Vernon Bailey, chief field naturalist of the Division, visited the 
type locality of Geomys brcvicejys, Prairie jMer Eouge, Morehouse Parish, 
Louisiana, in June, 1892, for the purpose of obtaining a series of duplicate 
types of the species. He found it common throughout the fields of the 
open country and along roads and fields in the woods of the flat land, 

JAN., 1895.] 

GiPiOMVg feREViCEPg. 133 

except wliere flooded, but uot in standing- timber or on hilly land. He 
states: "They do uot seem to be so common in cultivated land as in 
pastures and along fences and roadways. In one pasture of 20 acres 
we caught fifteen and one remained. They were more abundant at this 
point than elsewhere — probably twice as numerous to the area as they 
would average over the whole prairie. The damage done in tlie pasture 
by covering grass was trifling. This species does not seem to dig- 
extensively, and the hills are small. Usually one or two are thrown 
up in a night. In one place, where a gopher had run his tunnel in a 
straight course, I counted sixteen hills in a line (> rods long (measured). 
A hill of average size measured 24 by 15 inches in diameter and 5 
inches in height. Probably the reason the gophers do not dig more 
extensively is that food is abundant and the soil compact. The greatest 
damage the tiirmers claim from gophers, or 'salamanders' as they are 
called here, is that they carry the tubers of the troublesome cocoa or 
nut grass from place to place, often bringing them from a roadside or 
waste place and storing a large quantity in their burrows m gardens or 
fields and leaving them to grow where they had been kept out with great 
difticulty. This cocoa grass is one of the worst plants with which the 
farmers are troubled and is very difficult to get rid of when once started 
in the land. Small tubers are borne along the roots, and these are 
carried by the gophers, though I have not found them in their pockets. 
The stomachs examined contained green vegetable matter. White 
clover seems to be a favorite food. Most of the specimens taken were 
moderately fat. In June the young were half grown to nearly full 
grown. Of 27 specimens which I examined, 12 were males and 15 

Mr. C. L. Newman writes me that at Camden, Arkansas, this sj)ecies 
(specimen received for identification) is abundant in sections of the 
Ouachita River Valley, where they are known almost exclusively as 
'salamanders.' He says: "They seem to prefer old fields that have 
grown up in pine. I know of a place about a mile from Camden where 
the surface of about an acre of ground is mulched with loose earth 
brought from their burrows. Last year (1893) I caught twenty-tliree 
from about 6 acres of ground." 

* Mr. Veruoii Bailey coutribiites the following notes ou a specimen examined in 
the flesh at Mer Ronge, La., in June, 1892 : " Size small ; pelage very soft and silky ; 
skin loose, as though much too large for the hody ; body soft and flabby; soles of 
feet, nose, and end of tail hairless, smooth, shining, and Avhite Avhen clean. Lips 
hairy over the edges, but roof of mouth not hairy all the way across, a narrow line 
of smooth skin extending along the median line to the incisors; eyes small for a 
Gcomyn; cornea relatively large, measuring 3 mm. across, nearly ecjualing diame- 
ter of ball; no apparent lid, eye opening 3.5 mm. by 2 nun. (normally), its long 
axis parallel to a line drawn from ear to tip of nose; color of eye appearing shiny 
black; ears consist of a circular rim 1 mm. high and about 5 mm. in diameter; 
opening of meatus 2 by 2.5 mm., slightly elongated vertically; mustache spreading 
forward and back; distance from eye to end of nose 21 mm.; from eye to center of 
ear, 17 mm." 



(PI. 9, tig. 4.) 

Ti/jic from Clear Creek, Galveston Bay, Texas. No. MtJir c? f^tl- U. S. Nat. 
Museum, Department of Agriculture collection. C!ollected March 28, 1892, by 
William Lloyd. (Original number llSl.) 

Geographic distHhiition. — Gulf coast of Texas about (ralveston Bay. 

General characters. — Similar to brericepn^ but smaller aud more biglily 
colored; head very dark; throat aud fore feet i)ure white iu sharj) con- 
trast to dark of surrounding- parts. The skull differs in having a dis- 
tinct sagittal crest and in other particulars. 

('o?or,— Upper parts rich, glossy, russet brown, strongly tinged with 
fulvous, becoming dusky along the middle of the back and head (but 
no distinct dorsal band) ; entire head and nose very dark, almost black, 
but washed in j)laces with fulvous; inside of cheek pouches, chin, 
throat (breast also in some specimens), and "fore legs pure white in 
sharp contrast. On the upper side of the fore legs the dark color of 
the sides reaches down about half way to the wrists and ends abruptly 
with a sharp line of demarkation. The under side of the fore legs is 
pure white to elbow. The belly varies from whitish, strongly washed 
with buffy ochraceous, to fulvous. The Arcadia specimens are not 
exactly like those from the mouth of Clea?" Creek. 

Cranial characters (type specimen). — Skull similar to that of hreviceps 
but smaller; zygomata more divergent anteriorly (in male); nasals 
shorter and broader posteriorly, bringing the constriction much nearer 
the middle; aiulital bulhe smaller; ascending branches of premaxilla 
narrower posteriorly; temporal impressions meeting in a well marked 
vSagittal crest in male. In the female the temporal impressions never 
meet in a sagittal crest; the brain case is smoothly rounded, and the 
interparietal persists as a relatively large bone. 

In the Arcadia males the temporal impressions do not meet in a 
sagittal crest as m the type. 

Measurements (taken in Hesh). — Type: Total length, 225; tail verte- 
brte, 70; hind foot, 27. 

Average (of 5 males from Arcadia, Galveston County): Total length, 
220; tail vertebme, G4; hind foot, 26. 

Average (of 15 females from same place): Total length, 190: tail 
vertebni?, 54; hind foot, 23. 

For cranial measurements, see Table A, ]). 205. 

Specimens examined, — Total number 24: 4 from Clear Creek, Galves- 
ton Bay, and 20 from Arcadia, Galveston County, Texas. 

General remarl's. — To the northwestward sagiftalUs passes into the 
coastal plain form already mentioned under the head of G. hreviceps. 
Old males of this form sometimes develop remarkably broad skulls. 
The broadest skull that I have seen in the restricted genus Geomys is 
an old male from Brenham, Wasliington County, Texas (No. 63G12). It 
aft'ords the following measurements and ratios: Basal length, 40j 


basilar leiigtli ofHeiisel, 37; zygomatic breadth, 28.5, Ratio of zygo- 
matic breadtli to basal length, 71; to basilar leugth of Ileusel, 77. 


(PL 9, fig. 3.) 
Tfipe from Rockpout, Aransas County, Texas. No. 51382 ^ ad. U. S. Nat, Museum, 
Departmeut of Agriculture colU'ction Collected November IS, 1802, by H. H. 
Keays. (Original No. 3G.) 

Geograpliic (listribution. — Coastal plain and islands of Texas between 
Matagorda and Nueces bays; penetrates the interior to within a few 
miles of San Antonio. The south side of Nueces Bay is the home of 
another form [G. i)ersonat'US fullax). 

General characters. — Similar to G. br€vice2)s, but larger and less dark 
in color; feet and basal third to half of tail moderately well haired 
for a Geomys; terminal half to two-thirds of tail nearly naked ; zygomatic 
arches angular, strongly divergent anteriorly. 

Color. — Upper parts russet brown, becoming dusky on the head and 
usually along the median part of the back; under parts varying from 
soiled whitish to buflfy ochraceous. In some specimens the color of the 
ujiper i)arts is less fulvous than in others, and the dark dorsal band is 
variable; iu some specimens it is absent, sometimes the head is nearly 
black from end of nose to occii»ut, the blackish area limited laterally 
by the eyes and ears, the sides of the face being russet in rather strong 
contrast. The type specimen is in this pelage, except on the hinder jiart 
of the back and rump where the more fulvous summer pelage remains, 
without trace of the dorsal band. 

Cranial characters. — Skull similar to that of hreviceps, but frontal 
less depressed interorbitally; zygomata less spreading, strongly diver- 
gent anteriorly, more angular, more depressed, the maxillary arm slop- 
ing strongly backward; ascending branches of premaxilla broader and 
usually more abruptly truncate posteriorly; nasals shorter and normally 
convex instead of emarginate posteriorly. The nasals are normally so 
narrow posteriorly, and the premaxillje so broad, that iu some cases the 
latter nearly meet behind the former (as in the type si)ecimen, pi. 9, 
fig. 3). Normal skulls of attwateri differ markedly from those of fallax 
in the form of the zygomata, the maxillary arms sloping strongly back- 
ward instead of standing out at right angle, and the outer sides being 
strongly divergent instead of nearly parallel. The nasals are narrower 
and contracted posteriorly, the ascending arms of the premaxilla 
broader, and the audita! bulhe less swollen. In the series of lifty-two 
skulls of Geomys breviceps attwateri now before me, three depart from 
the normal in general outline, as seen from above, and resemble /ai^aa; 
in the form of the anterior part of the zygomatic arches, wliich stand 
out sc^uarely from the cranial axis and have the antero-external angles 

* Named in honor of Mr. H. P. Attwater, of San Antonio, Texas, who collected nearly 
all of the specimens. 


broadly rounded. In other respects tliey are typical attwaterl. All 
are very old males, collected at Kockport by Mr. Attwater (original 
Nos. 102, 118 and 110), They now belong to the American Museum of 
Natural History in 'New York. 

Meamirements (taken in flesh). — Type: Total length, 250 ; tail, 
85; hind foot, 30.5, 

Average of 10 males from type locality: Total length, 255; tail ver- 
tebra, 80 ; hind foot, 30. 

Average of 7 females from type locality: Total length, 220; tail ver- 
tebrae, 08 ; hind foot, 28. 

For cranial measurements see Table A, p. 205, 

Specimens examined. — Total number 53, from the following localities 
on or near the Gulf coast of Texas: Rockport, Aransas County (type 
locality), 40; Tallys Island, Aransas County, 3; Calaveras, Wilson 
County, 3; San Antonio (18 miles south), Bexar County, 7. 

General remarks. — Geomys hreviceps attivateri is a medium-sized 
species closely resembling its near neighbor G.fallax in color, though 
somewhat darker, and with the hind foot shorter. The resemblance to 
G. hreviceps is much closer in the plumbeous russet pelage than in the 
fulvous pelage. 

Mr. H. P. Attwater has kindly contributed the following memorandum 
respecting the habits of this gopher at Rockport, Texas : "As soon as the 
warm weather sets in, from about May to September, very few gophers 
are observed working. The soil is sandy, and at all times damp, 
dampness known as 'natural subirrigation.' In the hot weather the 
dampness does not come as near the surface as in the cooler months. 
I have thought that perhaps the gophers travel deeper in summer, but 
now think the chief reason why they do not throw up hills in summer, 
as they do in fall and winter, is that during the summer months the 
soil is so full of roots, suckers, bulbs, etc., that they do not have far to 
go before finding all they can eat, and that the reason they work so 
nuich after the summer months are over is because they are hunting 
around to fiud some bulb or root which was their favorite food in 
summer, and which they commenced to find about the month of May, 
and was over with in September. The animals are very abundant all 
over the i)eninsulas in Aransas County, wherever the soil is sandy. 
There is hardly a foot of laud that has not been 'plowed' several times 
over by gophers, and I believe the fertility of some sections has been 
greatly improved by them, by bringing the i)oorer soil up to the top. 
I have noticed that the richer the land the richer the gophers. Of 
course they do considerable damage to vegetable crops, especially to 
young fruit trees and cuttings just rooting. The samples sent you of 
mulberry trees cut by gophers were from the Faulkners' ranch, on St. 
Charles j)eninsula, in the eastern part of the county. Mr. Sanmel 
Walker, the manager of tlie ranch, told me that he killed over two hun- 
dred and fifty gophers in his young pear orchard between the 1st of 


March and April 15, 1893. This orchard was set out where sweet 
potatoes had grown the year before, and they came np again and cov- 
ered the gronnd, and I think the potatoes attracted the gophers in the 
first place more than the pear trees." 


(PL 9, fig. 2; pi. 13, tig. 12.) 

Type from Mason, Mason County, Texas. No. J^H 9 ad. Merriam collection. Col- 
lected by Rev. Ira B. Henry, December 17, 1885. 

Geographic distHbution. — Mason County, central Texas, and prob- 
ably thence southerly to the Kio Grande; limits of range unknown 
(map 4, E). 

General characters. — One of the smallest known species; tail short; 
terminal third nearly naked. 

Color. — Upper parts liver-brown, finely mixed with black-tipped 
hairs, much as m G. bursarius. Under parts and feet while. The hairs 
of the belly are plumbeous at base in the type and other winter 
specimens; in summer specimens they are white throughout. Throat 
suffused Avith pale bufty fulvous, forming a complete collar. In some 
specimens this collar is interrupted along the median line. The 
color of the upper jiarts is darker in winter than in summer, as 
usual in the genus. There is no trace of a dark dorsal band in adults, 
but in the young the black-tipped hairs are sometimes concentrated 
along the middle of the back, forming an ill defined dark streak. 

Cranial characters. — Skull small (smallest of the known species), 
smooth ; zygomata only moderately spreading and normally but slightly 
divergent anteriorly; nasals short, rather broad and convex or trun- 
cate behind; ascending branches of lU'emaxilla long, normally passing 
plane of lacrymals, usually straight on inner edge behind nasals and 
attenuate on outer edge; temporal imjiressions not forming distinct 
ridges and not uniting in a sagittal crest, usually separated by inter- 
space 1-3 mm. broad in adults; jugal short (shorter than basioccipital) ; 
interparietal broader than long, normally oval or elliptical and project- 
ing posteriorly behind plane of lambdoid suture; occiput bulging 
posteriorly more than in any other United States species (resembling 
Fappogeomys bulleri and some species of Thomomys). 

Skulls of texensis differ consi^icuously from those of G. arenarius in 
the following points: jSTasal branches of premaxilla longer and more 
pointed posteriorly; jugal more slender; no distinct knob at end of 
squamosal arm of zygoma; no distinct tem^joral ridges; inter j)arietal 
projecting posteriorly behind ijlane of lambdoid suture; occiput more 
bnlging posteriorly; mandible less heavy. G. texensis differs from G. 
breviceps in the shape of the nasal bones which are usually short, very 
broad posteriorly, with the sides nearly parallel. In G. breviceps they 
are usually longer, strongly wedge shaped, very narrow posteriorly, 
with the anterior third abruptly broader and flaring. In te.vensis the 
nasal branches of the premaxilla reach or pass the plane of the orbital 


fossa aud are pointed; in hreviceps they usually fall short of this plane 
and are bluntly rounded. In texensis the'jugal is shorter than tliehasioc- 
cijjhal; in brei^icips it is longer. In hreviceps the outer angle of the 
zygomatic arch is evenly rounded ; in texensis it is angular and abruptly 
flattened (or even excavated) on its infero-external face, beginning at 
the angle and extending posteriorly under the jugal (as seen from the 
side). The. inflated mastoids and audital bulhie are larger in hreviceps, 
in which species the mastoids are conspicuously broader than in texen- 
sis, the exposed part, viewed from behind, being as broad as high, while 
in texensis the breadth is only about half the height. But the range 
of individual variation is so great that much confidence can not be 
placed on this character.* In hreinceps the frontal is flatter and 
depressed interorbitally, forming a slight concavity in the plane of the 
upper side of the skull when seen in profile; in texensis the profile is 
convex at this point. 

Skulls of Geomys texensis difter Irom those ot 6^. bursar ins, in addition 
to their much smaller size, in shorter rostrum and brain case, less promi- 
nent ridges and i^rocesses for muscular attachments, absence of sagittal 
and lambdoidal crests fit all ages; much larger iiiter])arietal; uuich 
larger andital bulhe (which are inflated and rounded antero-laterally 
instead of flattened), and in the greater length of theascending branches 
of the premaxilhi posteriorly. Tlie skull as a whole is not only much 
smaller than that of hnrsariiis, but is relatively thin and smooth, like 
that of Tltomomys. The arch of the brain case is low, but not so flat as 
in hreinceps, and the temporal impressions never mret along the median 

Measurements. — Type specimen : Total length, 20."} (measured in flesh) ; 
hind foot, 28 (in dry skin moistened to straighten the toes). Tail not 
measured in flesh, but short; about 00 in dry skin. Average total length 
of 28 specimens from tyi)e locality measured in flesh, 210. 

For cranial measurements see Table B, p. 200, 

Specimens examined. — Total number 31, from the following localities 
in Texas: Mason, Mason 0(mnty (type locality), 28; Laredo, 1; Syca- 
more Tree (on liio Grande), 1; Del Itio (on Eio Grande), 1. 

General remarls. — Geomys texensis is a small white bellied species 
inhabiting central Texas. Its back is chestnut-bvown or liver-brown, 
much as in the large dark-bellied G. hursarius, with which it requires 
no comparison. It is the smallest species in the United States, about 
equaling Pappogeoniys hnlleri of Mexico. The only bisulcate species 
of approximately the same size are G. hreviceps of Louisiana and its 
subspecies saaittaUs of the Gulf coast of Texas, and G. arenarius of 
the Upper Rio Grande Valley in extreme western Texas and south-cen- 

* The actual size of the mastoid is often hidileu by the thin outer edge of the exoc- 
cipital which overlies its iuner border, aud which is not always alike on the two 
sides. Hence it sometimes happens that the exposed part of the mastoid is narrow 
ou one side and broad ou the other. 


tral New Mexico, with all of which it may iutergracle, although it differs 
widely from them all in color aud cranial characters, as elsewhere 
shown. On the north, in Oklahoma and southern Kansas, it i)robably 
intergrades with G. lutescens. 

Three specimens of a small Geomys from as many points in the Eio 
Grande Valley (Laredo, Del Kio, and Sycamore Creek) are provision- 
ally referred to the jjresent species. The Laredo >specimen lacks the 
skull and its upper parts are more drab than usual. The specimens 
from Del Rio and the mouth of Sycamore Creek are too immature for 
positive identitication. They differ from the young of texensis from 
the type locality in having longer tails, somewhat darker backs, and 
in lacking the chestnut tint on the sides. Their skulls seem to be 
intermediate between texensis and arenarins. Mr. William Lloyd, who 
collected the Sycamore Creek specimen, states that the species is 
rare there and was found only in a belt of fine sand along the Rio 
Grande. He found a species, presumably the same, on chalky soil near 
Comstock. 'Slw Vernon Bailey collected the Del Rio specimen in the 
river bottom, where the species was rather rare. 


(PL 9, fig. 1; pi. 13, fig. 13.) 

Type from El Paso, Texas. No. \r.wxl ,i ad. U. S. National Museum, Deiiartmentof 
Agriculture collection. Collected Deci'ml)er 13, 1889, by Vernon Bniley (Orig- 
iual No. 798). 

Geouraphic distribution. — ^' alley of the Upi)er Rio Grande, from El 
Paso, in extreme western Texas, and Juarez, Chihuahua (on the Mexi- 
can side of the river opposite El Paso), north to Las Cruces, New Mex- 
ico, and west to Deming, in the same state (map -1, a). It will prob- 
ably l)e found to follow the valley somewhat further in both directions, 
and to the east may intergrade with texensis. So far as now known its 
range seems to be separated by a broad interval from that of the spe- 
cies inhabiting central and southern Texas, the westernmost records of 
which are Del Rio and Comstock, in the Rio Grande Valley. Curiously 
enough the intervening region is inhabited by a widely different Pocket 
Gopher, one belonging to the unisnlcate series, namely, Cratof/eomi/s 
castanops. The ranges of all the other bisulcate species, except /«://, 
are either directly continuous or contiguous. In faunal position G. 
arenarins belongs to the upper edge of the Lower Sonoran Zone. 

General characters. — Size medium; tail rather long and unusually 
well haired, except near tip; coloration pale. 

Color. — Upper parts drab-brown, finely mixed with black-ti])ped 
hairs; under parts and feet white. In some specimens the color of the 
sides encroaches on the belly and is only partly masked by the white 
tips of the hairs. 

Cranial characters. — Skull resembling Thomomys talpoides; size rather 
small (intermediate between texensis ^nd hreviceps) ; zygomata normally 


narrow and nearly parallel (in one S from El Paso, No. 58340, they are 
exceptionally divergent anteriorly) ; no sagittal crest at any age; tem- 
poral ridges prominent, distant, and nearly parallel or slightly diver- 
gent anteriorly, usnally separated by a flat or concave interspace 4 to 
5 """ wide, as in Thomomys talpoides ; squamosal arm of zygoma ending 
in a prominent knob over middle of jugal (diagnostic of the species); 
jngal short (shorter than basioccipital); interparietal rather large, 
normally (but not always) broader than long, usually siibquadrangular 
or with the corners rounded anteriorly, truncate posteriorly on plane 
of lambdoid suture; occiput bulging posteriorly, but not solar as in 
texensis; palatopterygoidsnormally abruptly narrow, their sides nearly 
parallel (but form somewhat variable); mandible heavy fur size of skull. 
The fenmles diifer fr<mi the males in having shorter nasals, larger par- 
ietals, and less prominent temporal ridges. As a rule the interspace is 
somewhat thickened and the ridge is evideut from the outer side only. 

The skull of G. arenarius differs from that of texensis in the follow- 
ing characters: Jugal heavier and broader; temporal ridges much 
more prominent and distant; a prominent knob at distal end of squa- 
mosal arm of zygoma; top of skull flatter; frontal broader and flatter 
interorbitally; iuterparietal truncate posteriorly on plane of lambdoid 
suture; occiput less bulging. It differs from lutesccns in much smaller 
size, narrower and uiore parallel zygomata; shorter jugal; in the 
presence of well-developed distant temporal ridges, ami of a prominent 
knob at distal end of squamosal arm of zygoma; shorter and somewhat 
narrower nasals, and shorter ends of ascending arms of premaxilla 
behiud the nasals. 

Measureynenis [taken in flesh). — Type specimen ( S ad.): Total length 
258; tail vertebrae, 88; hind foot, 33. Average of 8 males from type 
locality: Total length, 200; tail vertebr;Te, 83; hind foot, 32. Average 
of 24 females* from type locality: Total length, 250; tail vertebne, 78: 
hind foot, 32. 

For cranial measurements see Table B, p. 207. 

Sjyecimens examined. — Total number 43, from the following localities: 
Juarez, Mexico, 3; El Paso, Texas, 30; Deming, New Mexico, 3; Las 
Cruces New Mexico, 7. 

General rcmarlxs. — In color and external appearance Geomys arenarim 
closely resembles the typical form of G. Ititescens (from western Ne- 
braska and eastern Wyoming), differing chiefly in smaller size and in 
greater length and hairiness of tail. From its nearest ally in central 
Texas (G. texensis) it differs both in color and proportions, having the 
upper parts pale drab instead of reddish brown, and the tail long and 
hairy instead of short and nearly naked. In cranial characters it may 
be distinguished from all other species by the presence of distant tem- 

* Some of tlae si)eciinens recorded as females are very largo and were probably 
males; hence the averages here given for females are ijrobably too great. 


poral ridges or ribs, wliicli are nearly parallel, in connection with the 
develoi)inent of a prominent knob at the distal end of the squamosal 
arm of the zygoma. 

This fine cpecies was discovered by my assistant, Mr. Vernon Bailey, 
at El Paso, Texas, in December, 1889, and was obtained by him at 
Deming, New Mexico, also. Mr. J. Alden Loring-, who was sent to the 
Upper Rio Grande Valley to work out its range, secured a large series 
iVom Las Cruces, New Mexico, and Juarez, Chihuahua, Mexico, as well 
as at the type locality. El Paso, Texas. Mr. Loring says: "They 
are not very common on the Mexican side of the river, but extremely so 
on American soil, where they seem to thrive and grow fat. The places 
they most prefer are railroad embankments and irrigation ditches, 
where they were found both in sand and wet, dark clayey soil. Two 
were seen on February 5 just as they protruded their heads from their 
holes. Their faces were covered with dirt, and as soon as they had 
shaken it ott' they saw me and quickly dodged back. When these 
Gophers were caught I noticed that they walked with the claws of the 
front feet partially doubled under, which did not aUow the sole of the 
foot to touch the ground." 


(PI. 12, fig. 4; pi. 13, fig. 14; pi. 14, fig. 4.) 

(ieomijs personatus True, Proc. U. S. National Museum, xi (for 1M88), Jau. 5, 1889, 

Type locaUty. — Padre Island, Texas. 

Geographic distribution. — The Tamaulipan fauna of Texas, comprising 
Padre Island and the adjacent mainland southwesterly to Carrizo on 
the Rio Grande (map 4, f). 

General characters. — Size large; coloration jjale; tail long, scant- 
haired on proximal half and nearly naked on distal half. 

Color. — Upper parts pale drab (darker in winter from more liberal 
admixture of dark-tipped hairs) ; middle of face from nose to above eyes 
inclining to dusky. Under parts white, sometimes obscurely clouded, 
from the presence of irregular patches of hairs with plumbeous bases, 
the hairs on other parts of the belly white to roots. Tail hairs white, 
but too far apart to give color to the nearly naked tail. 

Cranial characters. — Skull large, heavy, with well-developed proc- 
esses and ridges and a high sagittal crest (pi. 12, fig. 4); zygomata 
standing out at right angle to axis of skull; jugal bluntly and broadly 
rounded anteriorly, and short, not longer than basiocciptal (measured 
from condyle); nasals long and narrow, anterior third spreading; 
frontal narrow interorbitally, the orbital borders rounded; basioccipital 
with sides parallel, or nearly parallel. In profile the top of the skull 
(including the sagittal crest) is nearly a straight line. 

Adult skulls of Geomijs personatus may be easily distinguished from 
those of bursarius and liitescens by the squareness of the zygomatic 



arches anteriorly, the shortness of the jugal bone anteriorly, with cor- 
responding prodnction of the maxillary arm of the zygoma. The greatest 
length of the jngal in personatus is only eijual to the length of the basi- 
occipital bone (measured from the condjde). In both hursarius and 
lutesccn.s the jugal is much longer than the basioccipital. In personatus 
the skull as a whole is relatively as well as actually longer, and nar- 
rower across the zygomatic arches, than that of IntcscenSj from which 
it differs further in the following particulars: zygomatic breadth 
usually less than distance from foramen magnuui to incisive fora 
miua (the contrary being usually true in lufescens); ascending branches 
of premaxilla extending much further iiosteriorly ; zygomatic arches 
relatively long, only moderately spreading anteriorly (except in 
extreme age), but standing out at right angle to longitudinal axis of 
skull; orbital fossfe elongated antero-posteriorly instead of subtri- 
angular; length of frontal along median line usually equal to length of 
nasals (ommonly shorter in lutescens) ; audital bulhe longer, with outer 
side flattened; inflated mastoid smaller. Skulls of personatus average 
longer in proportion to the zygomatic breadth than those of any other 
known bisnlcate species, except the Mexican Zygogeomys trichopus 
(the ratio of zygomatic breadth to basilar length ranging from 68 to 
72 percent), though in this respect they differ but slightly from Geoniys 

Measurements. — Of 13 specimens (of Ijoth sexes) from type locality 
(Padre Island): Total length, 399; tail vertebr;^, 103; hind foot, 37. 
Average of 4 males: Total length, 315; tail vertebrje, 111; hind foot, 
40. Average of 9 females: Total length, 293; tail vertebra} 100; hind 
foot, 36. 

For cranial measurements see Table B, p. 206, 

Specimens examined. — Total number 33, from the following localities 
on or near the Gulf coast of Texas: Padre Island (type locality), 15; 
nenr Santa Kosa, 8; Sauz Kancho, 6; Carrizo, 3. 

Number of subspecies /aZ/aj? 22, as follows: Nueces Bay and River 
^south side), 6; Corinis Christi, 15; Las Mottes, 1. 

Departures from the type. — The type locality of Geomys personatus is 
Padre Island. Fairly typical specimens are at hand from points ou 
the mainland west of the southern part of this island, namely, Santa 
Rosa and the Arroyo Colorado (Sauz Rancho), and also from Carrizo 
on the Rio Grande, though the latter depart somewhat from the type. 
Singularly enough, specimens from the lower Nueces River and Bay, 
and from Corpus Christi and Las Mottes, differ decidedly from the typ- 
ical animal in smaller size, darker color, and in important cranial charac 
ters. The skull is much smaller, more abruptly truncate posteriorly, 
with more spreading zygomatic arches, and much more globular audital 
bulla' (pi. 12, fig. 3). This form is here separated sub-specifically under 
the name Geomys personatus fa llax (see p. 144). Intergradation between 
personatus and/aZ/aa; probably occurs in the narrow strii) between Santa 


Rosa and Corpus Christi Bay, since the single specimen from Las 
Mottes, a few miles south of Nueces Bay, is somewhat larger than the 
Nueces Bay and Corpus Christi specimens. 

Some of the specimens from Santa Rosa are fairly ty])i<ml jJer son at us, 
though all have more swollen audital and mastoid bulhe. One adult 
skull (No. 42,860) from the Arroyo Colorado (Sauz Rancho, about 50 
miles north of Brownsville) has a very narrow rostrum, narrow zygo- 
mata, projecting occiput, very much swollen mastoid and audital bulhe 
(the latter almost subglobular) and abnormally short and narrow jugal. 
Five other skulls from the same locality are young and apparently less 
extreme. The adult skull may be regarded as abnormal, or as pointing 
to the differentiation of an incipient race. 

General remarJcs. — (Jeomys personatus resembles G. lutescens in sum- 
mer pelage more closely than any other form. The typical animal may 
be distinguished from lutescens at all seasons by larger size, longer feet 
and tail, by important cranial characters (just described in detail), and 
by the white of the under parts. In summer specimens of G. lutescens 
the belly is sometimes pale, but rarely white except in the very young. 
The color of the upper parts in summer pelage differs but little in the 
two species, being drab in both, with the nose and middle of the fiice, 
as far back as the eyes, inclining to dusky; but in winter and early 
spring the two differ notably, the dusky face markings of lutescens 
extending posteriorly over the head and back to the rump, forming a 
distinct dorsal stripe. In this pelage, also, the under parts are much 
darker, the fur being dark plumbeous, tipped with drab. While per- 
sonatus is the larger of the two animals, the claws of the fore feet are 
equally large (and relatively larger) in lutescens. In some specimens of 
personatus the claws are remarkably long and slender — the result, doubt- 
less, of the unresisting character of the sand in which the animals live. 

The geographic distribution of Geomys personat\is (including sub- 
species fallax) appears to coincide with the limits of the arid tropical 
area of Texas — an area recognized and defined by me in 1892,* and sub- 
sequently named the Tamaulipan fauna by Allen.t The range of the 
species has been ascertained to terminate abrujitly both on the north 
and on the west, specimens from a few miles north of Corpus Christi 
Bay, and from Laredo on the Rio Grande, belonging to different species. 

Mr. William Lloyd, who collected the si)ecimens, statesthat G. person- 
atus IS abundant in a patch of fine sandy soil above (!arrizo, but was 
not found elsewhere in the neighborhood. He sti.tcs further that in 
traveling north from the mouth of the Rio Grande it was first met on 
entering the great sand belt on the north side of the Arroyo Colorado 
(at El Sauz), It continued throughout this sand belt, becoming more 
abundant to the northward. On Padre Island he found the animals 
living in colonies, perhaps a mile or more a]>art, and common from the 

"Presidential Address, Proc. Biol. Soc, Washington, April, 1892, p. 33. 
t Bull. Am. Museum Nat. Hist., Kew York, Vol. iv, Jan., 1893, 241-242. 


north end to tlio center of the island, but not within 20 miles of the 
south end. Mr. Lloyd says: ''Their habits are in some respects pecu- 
liar, o\Yin!4' i)erhaps to the soft sand that caves iu on them, or to fear 
of the coyotes, or for both reasons; they fill uj) their tunnels for a yard 
or two almost immediately after they throw out the dirt. They can 
not go very deep iu the flats or they would reach water; in fact, the 
water filled some of the tunnels for about a foot until they curved 
upward. Not more than one is ever found in a hole. " 


(PI. 12 fig. 3.) 

Typo from south side of Nueces Bay_. Texas. No. f |?^i <? ad. Collected Novem- 
ber 30, 1891; by William Lloyd. (Original No. 949.) • 

Geographic distribution. — South shore of Nueces Bay and lower 
Nueces Eiver, Texas; further south passing into G. personatus. 

General characters. — Similar in external appearance to G. personatus 
of Padre Island, but much smaller (only about half the bulk of that 
species); somewhat darker; tail shorter and nearly naked. 

Color. — Upper parts drab-brown, darker in winter; paler and more 
fulvous in summer; nose and face between eyes dusky; sometimes an 
ill-defined dusky band along the middle of the back. Under parts 
usually marbled with pure white and i^atches of dark hair (the white 
hair being white to roots). 

Cranial characters. — Skull similar to that of personatus, but very 
much smaller (pi. 12, fig. 3). The zygomata stand out squarely at right 
angles to axis of cranium and are widely spreading, their outer sides 
nearly x^arallel; the temporal impressions meet in the males in a well- 
marked sagittal crest; in the females they remain apart, separated by 
an interspace about 3 millimeters wide; nasals rather broad and blunt 
posteriorly; jugals short (not longer than basioccipital) ; mastoid and 
audita! bulhe swollen, the latter short and rounded; palatoptery golds 
narrow, their sides nearly parallel. Skulls of fall ax differ from those 
of personatus in very much smaller size, shorter (and usually blunter) 
ascending arms of premaxilla, more squarely truncate occiput (lamb- 
doid crest less convex posteriorly), and in much shorter and more 
swollen audital bulhc. 

Geomys personatus /aZ/aa? differs markedly from G.attivateri (which 
it approaches in size) in the form of the zygomata, the maxillary arm 
standing out at right angle instead of sloping strongly backward, and 
the outer sides of the arches being nearly parallel instead of strongly 
divergent anteriorly. It differs farther in having more globular audital 
bullae, broader nasals, narrower ascending branches of the i)remaxilla, 
and in the males a well-developed sagittal crest instead of permanent 
temporal ridges. 

Measurements. — Type specimen : Total length, 250; tail vertebrai,80; 
hind foot, 35. Average of 9 males from south side of Nueces Bay : Total 


length, 263; tail veitebnu, 87; kind foot, 34. Average of 10 females 
from same locality: Total length, 236; tail vertebrse, 75; hind foot, 31. 

For cranial measurements see Table B, p. 20r). 

S2)ecimens examined. — Total number 32, from the following localities 
on or near Nueces Bay, Texas: oS^ueces Bay, 4; Nueces River, 10 miles 
from mouth, 2; Corpus Christi 15; Las Mottes, 1. 

General remarks. — Geomys fallax is a miniature of G. 2>ersonatus, 
both in external appearance and in the general form of the skull. It 
is hardly more than half the bulk and weight oi personatus^ from which 
it differs further in somewhat darker coloration and in cranial details. 
The geographic range of the typical form is remarkably restricted, 
being limited, so far as known, to the south side of the lower Nueces 
Kiver and Bay. 

In his notes on mammals observed in southeastern Texas, Mr. William 
Llo3'd states that this species "is abundant in all soils, although it 
prefeis the black loam. On Nueces Bay they burrow in the sand close 
to the water's edge, but are most at heme on the highest point attain- 
able. I have seen an unbroken line of hills extending from 70 to 100 
yards across patches of early pease and onions. They cause havoc 
among the sweet potatoes, coming above ground to eat them in the 
daytime. I shot a marsh hawk that was flying oft with a gopher which 
had been thus engaged. While driving along the road cats may be 
seen frequently a mile from the house intently watching the gophers' 
holes. The gophers are known to be great pests to fruit and other 
trees; in more than a dozen instances near the bay I have seen the 
huisachi [Acacia farnesiana) leveled by their work in chewing the 
rootlets and digging the earth away from the roots." 

Genns PAPPOGEOMYS * nob. 

(PI. 11, lig. 1; and text figs. 56, .57 and 58.) 
Type Geomys hiiUcri Thomas, from Talpa, Mascota, Jalisco. 

Dental characters. — Upper premolar with three enamel plates, the 
posterior absent; m' and m^ with two enamel plates each, as in Geomys. 
Last upper molar an imperfectly double prism; a single sulcus on outer 
side, behind which the crown is narrowed, forming a moderately well- 
defined heel; outer enamel plate bent slightlj' outward near its anterior 
end. Upper incisor unisulcate, the sulcus median and deep (no trace 
of minor sulcus; see fig. 21^). 

Cranial characters. — Skull small, short, rather smoothly rounded ; a 
broad sagittal area (no sagittal crest at any age, pi. 11, fig. 1); zygo- 
mata slender, rather broadly and squarely spreading, without trace of 
angular expansion; occiput bulging posteriorly; palatoi^terygoids little 

''Pappof/eomys, from TrdTTTrof, grandfather, + Geomys, in reference to the apparent 
antiquity of the type. 

7433— No. 8 10 



[NO. 8. 

more tlian vertical lamelliv, slightly everted iiiferiorly ; orbital plates of 
frontal separated interiorly by full breadth of cribriform plate as in 
Tliomomys; orbitosphenoids broad, articulating firmly Avith alisphenoids 
and sending a tongue upward to nearly fill the upper x)art of the sx)he- 
uoidal fissure; mesetlimoid a nearly vertical plate much higher than 
long, its inferior edge dipping down between wings of vomer posteri- 
orly; endoturbinals as in PlatygeomySj the first sharply triangular and 
the OS planum trimmed closely in front of the others. 

Fi(i. 56. — I'appoij'MiHys biiUeri. Vault of cranium sawed off, showing floor of brain case. 
(For key see tig. 9). 

Fm. 57.—Pappo(jeomt/s bulleri. Vortical longitndiual section of skull, mesetbmoid and vomer 
in place. (For key see fig. 7). 

Fig. bS.—Pappogeomys bulleri. Mesothmoid and vomer removed to show endoturbinals. 
(For key see fig. 10). 

External eharacters. — iH/.e small; pelage soft; form Thomomine. 

General remarks. — Pappogcomys holds an interesting position with 

eference to the trunk line of the Geomyldw. Tn dental characters it 

combines the inolariform enamel pattern of Geomys with the unisulcate 

incisors of Cratogeomys and Platy geomys; and in cranial characters it 


exhibits striking resemblances to both Geomys aud Thomomys on the 
one hand, aud to Craiogeomys on theotlier. The endoturbinals are not 
widely different from the Geomys type, while the orbitosphenoids depart 
entirely from Geomys and surpass Craiogeomys in the extent of their 
development aud articulations. They cut off" and shorten the sphe- 
noid fossa^, which in Geomys reach forward to the orbital plates of the 
frontal (pi. 17, fig. 3), The shape of the mesethmoid plate is unique. 
The form of the skull as a whole is very like the simpler forms of 
Thomomys and Geomys — as texensis aud arenarius — aud the permanently 
distant orbital plates of the frontalis a decidedly Thomoiuine character. 
The resemblances to Geomys aud Thomomys do not indicate that 
Pappogeomys has descended from either of these genera, but that it 
occupies a place near the trunk line and below the point from which 
they branched off". On the other hand, the resemblances to Cratogeomys 
and Platygeomys are prophetic, indicating a position near the base of 
the great bram^h that afterward gave rise to these more specialized 


Mastoids small, truncal e above hnUcri. 

Mastoids large, rounded above albiiiasus. 


(PI. 11, fig. 1; pi. 13, tig. 15; pi. 14, tig. 11.) 

Geomys huUeri Thomas, Auuals aud Magazine Nat. Hist., 6 series, Vol. x, August, 1892, 

p. 196. 
(leomijs neJsoni Merriam, Proc. Biol. Soc., Washington, vii, September29, 1892, 164-165. 

Type locality. — IsTear Talpa, west slope of Sierra de Mascota, 
Jalisco, Mexico (altitude, 8,500 feet). Type in British Museum. 

Geographic distribution. — Lower slopes of Sierra Nevada de Oolima 
and Sierra de Mascota, Jalisco, Mexico (map 3'). 

General characters.* — Size smallest of the known unisulcate species, • 
of which it is a generalized type; skull small aud smooth, resembling 
Thomomys; tail naked; a naked pad on end of nose, partly inclosed in 
a pale patch. 

Color. — Upper parts rich rusty chestnut; underparts paler. An 
innnature but full-grown specimen (Xo. 33585) is dusky in color, aud 
one in the molt has the anterior parts chestnut and the posterior dusky. 

Cranial characters. — The skull of Pappogeomys bulleri is small and 
smoothly rounded, with broadly distant and rather feeble temporal 
ridges. The maxillary arms of the zygomata stand out at right angles 

" The following description is based wholly on specimens from the north slope of 
the Sierra Nevada de .lalisco. They are larger than Thomas's type and only speci- 
men of (i. bnlleri, and may prove subspecihcally separable, in which case the name 
nehoni will be available. 


to the axis of the skull; the zygomata are slender, rather widely spread- 
ing, without trace of expanded angle, and their outer sides are nearly 
parallel (sometimes broader posteriorly than anteriorly). The occiput 
bulges far behind the lambdoid suture and is smoothly rounded (except 
in old males, in which it is less inflated and is marked by a median ver- 
tical ridge). In all of these respects it agrees with the closely related 
P. alhinasus and differs from all other known Mexican species. The 
frontal is broad and rather tlat interorbitally ; the nasals narrow and 
truncate posteriorly; the ascending branches of the premaxilla short, 
bluntly rounded posteriorly, and barely reaching plane of orbits. The 
pterygoids are parallel lamelhe, their inferior edges slightly everted — 
a transition step in the development of the horizontal shelf of Crato- 
geomys from the simple lamella of Thomomys. The hamular processes 
articulate directly with the audital bulliie. P. bullerl differs from the 
nearly related P. alhinasus in smaller size, smaller mastoids (which are 
truncate above instead of rounded), narrower rostrum, narrower and 
longer nasals, narrower ascending branches of premaxilla, and much 
shorter angular process of mandible. 

Dental characters. — Upper incisors narrow, with a single median fur- 
row; molariform series only slightly heavier than in G. texensis; last 
upper molar with a large heel, which equals or exceeds the anterior 
prism in antero-posterior diameter. 

Measurements. — Average of 2 males from north slope of Sierra Nevada 
de Colima, Jalisco (measured in flesh) : Total length, 236 ; tail vertebra", 
81.5; hind foot, 33. Average of 4 females from same locality: Total 
length, 215.5; tail vertebr;B, 72.5; hind foot, 30.* 

For cranial measurements see Table F, p. 214. 

Specimens examined. — Six, all from the north slope of the Sierra 
Nevada de Jalisco, Mexico. 

General remarks. — This species Avas described almost simultaneously 
by Mr. Oldfield Thomas and myself, but his description has priority of 
publication by about a month. Hence his name, hulleri, has precedence 
over my nelsoni. Mr. Nelson states that the species " was found only 
in some fields at the upper ranch at the foot of the main north slope of 
the Sierra Nevada de Colima, Jalisco, in the upper border of. the lower 
pine belt, at about (3,500 feet altitude, where it was common, and was 
found in company with the large species, Geomys gymnurus.^^ 

Pappogeomys hulleri greatly resembles the bisulcate Geomys texensis, 
from which its dental characters distinguish it at a glance. It is evi- 
dent that both bulleri and texensis have undergone but little modifica- 

* lu my original description of (f. nelsoni, the measurements were taken " from 
dry skin of type [ (? ], slightly overstaffed," the field measurements not having been 
received (Proc. Biol. Soc, Washington, vii, Sept. 29, 1892, 164.) The measurements 
as published were: Total length, 250; tail vertebr;ie, 80; hind foot, 30. The flesh 
measurements of the same specimen are: Total length, 238; tail vertebrse, 83; hmd 
foot, 33. Mr 'J'homas' measurements of his type specimen of bulleri are: Head aud 
body, 135; tail, 63; hind feet, with claw, 27,6. 

JAN., 1895.] 


tioii since they left the main trunk Hue of the group, aud that both 
branched off from points not very remote from the place where Tho- 
momys left the same stock. 


Type from Guadalajara, State of Jalisco, Mexico. No. i^^f 9 ad. U. S 
National Museum, Department of Agriculture collection. Collected at Atema- 
jac, a suburb of Guadalajara, May 21, 1892, by E. W. Nelson (Original No. 2654). 

Geographic distribution. — The plain of Guadalajara; limits of range 
unknown, Mr. Nelson states: "This species occurs very sparingly on 
the open plain about Guadalajara, and diggings of a small gopher, 
l^robably the same species, were seen near Ahualulco, some 35 miles 
farther west. The range in altitude of these locahties lies between 
4,000 and 5,100 feet.'' 

General characters. — Size small; naked nasal pad well developed; 
tail naked. Animal similar to P. huUeri of Thomas, but somewhat 
larger; nasal pad and white patch above it more elongated; color paler; 
whiskers finer and less conspicuous. 

Color. — Uniform pale plumbeous above and below, irregularly washed 
with pale chestnut, palest below; a small dark patch around each ear; 
an elongated white i)atch on nose inclosing nasal pad and reaching 
posteriorly nearly to plane of eyes. 

Cranial characters. — Skull small, smoothly rounded like Thomomys; 
zygomatic arches parallel, .slender, angle not expanded; temporal 
impressions widely distant; zygomatic breadth slightly exceeding 
greatest breadth of cranium posteriorly. Skull similar to that of P. 
hnUeri,hnt differing in larger size; much larger mastoids, wliicli are 
rounded above instead of truncate; broader muzzle; shorter and 
broader nasals; broader ascending branches of premaxilla, and more 
elongated angular processes of mandible. 

Measurements in flesh. — Type specimen 9 ad. Total length, 226; tail 
vertebrte, G8; hind foot, 31. 

For cranial measurements see Table F, p. 211. 

General remarks. — The only known species requiring comparison with 
P. alhinasus is the related P. hulleri of Thomas, a smaller and much 
more highly colored animal, differing in the cranial characters above 
pointed out. ' Future investigations may show that the ranges of the 
two meet, and that the animals intergrade, in which case alhinasus will 
become a subspecies of hulleri. 

Unfortunately, only a single specimen of Pappoyeomys alhinasus is at 
hand. But since its type locality, Guadalajara, is an attractive and 
accessible locality. It is probable that a large series of specimens will 
be obtained in the near future. 


Genus CRATOCJEOMYS ' nob. 

(PI. 2; pi. 10, fig. .5; pi. 12, figs. I and 2; pi. 13, fig.s,4-8, and 17; pi. 14, figs. 6 and 7; 

pi. 15, figs. (5 and i»; pi. 17, tig. 5; pi. 18, fig. 4 ; pi. 19, fig. 6.) 
Type Geomys merriami Thomas, from the Valley of Mexico (pi. 2). 

Dental characters. — Upper premolar with three enamel plates (the pos- 
terior absent), its shaft strongly convex forward; upper and lower pre- 
molars subequal in leugtli. First and second 
upper molars with one enamel plate each (pos- 
terior absent) ; posterior curvature of m' and m'^ 
and anterior curvature of nii and m2 strong. 

Last upper molar an imperfectly double prism ; 
a deep sulcus on outer side; no sulcus on inner 
side; crown of tooth normally broader than 
long, variable in form, usually more or less ob- 

FiG.59. — Cratogeomysiner- , . -, , • i • -, , , 

riami. Crowns of moiari cordatc or subtriaugular ; inucr and outcr cnainel 
form teeth: a, upper; b, platcs Variable; inner plate normally at least 
^""^^^ two-thirds as long as anterior plate, obliquely 

transverse, normally covering posterior face of tooth. 

Upper incisor with a single sulcus, median or slightly on inner side, 
and usually rather open (fig. 21', 2P, and pi. 15, fig. 9). 

Cranial characters. — Skull large and massive; zygomata heavy and 
rather broadly spreading ; orbitosphenoids short and broad, articulating 
with alisphenoids anteriorly; niesethmoid a half crescent, its apex 
pointing to presphenoid; endoturbinals together forming a compact 
plate, strongly convex below, straight above, its anterior border sloping 
strongly backward without any extension of the os planum in front of 
the folds (pi. 19, fig. C) ; first endoturbinal moderately expanded and 
elongated; second, third, and fourth subequal; vomerine edge of os 
planum curving down below plane of roof of narial passage; floccular 
fossa circumscribed and separated from internal auditory meatus by a 
distinct ridge; ridge separating inner from superior face of petrous 
sharp and incurved, and sometimes rising high posteriorly (pi. 17, fig. 
5, and pi. 18, fig. 4). 

The following additional characters, of more or less weight, are intro- 
duced with special reference to antithesis with Platygeomys: t Breadth 
of cranium posteriorly (above mastoids) much less than zygomatic 
breadth ; breadth of occipital plane not more than twice its height ; lamb 
doid crest broadly convex i^osteriorly ; squamosal expansion chiefly 
toward the median line (in C. merriami in advanced age they comx)letely 
cover and conceal the parietals, above which they meet in a median 
crest) ; mandible longer than broad (including incisors) ; angular process 

* Cratogeomys, from uparo^, strong, powerful, -f- Geomijs, in reference to the great 
size and strength of the animals. 

t Many of the characters already given in the generic diagnosis are also in strong 
contrast to those of riuti/geomys. 



of maiulihle short, nearly sessile, truncated externally, and forming a 
shelf (•onii)letely around the base of the outer side of the incisor knob; 
S(iuaniosal arm of zygoma covering nearly or quite two-thirds of jugal, 
which latter tills but a narrow gap in zygomatic arch (except in one 
species, C.fulvescens, in which the jugal is abnormally short posteriorly, 
its anterior relations being normal); free part of ui)per edge of jugal 
half or less than half the length of basioccipital on median line: paroc- 
cipital j)rocesses relatively light; incisors heavy in contrast to those 
of riaty(/comys (except in fulvescen,s and castanops); antero-posterior 
diameter of incisors greater than transverse (except lufiilvescens and 
castano2)s) ; enamel face of lower incisors forming a conspicuous bead 
on outer side of tooth, behind which the tooth is strongly beveled, the 
transverse diameter being much greater through the enamel face than 
posteriorly (except in fulvescens and castanops). 

In Cratogeomys a marked depression extends obliquely across the 
sq^iamosals from the root of the zygoma to the occiput near the median 
line. In the gymmirus series no such depression exists, but, on the con- 
trary, a distinct bulge or elevation occupies this part of the skull. 

Cratocjeomyti splits naturally into two sections: The merriami series, 
comprising merriami, perotensis, estor, oreocetes, audperegrinus; and the 
castanops series, comprising castanops and fulvescens. In the merriami 
series the top of the skull seen in profile is a nearly straight line; the 
zygomata are not strongly decurved, and the outer angle is only mod- 
erately expanded. In the castanops series the top of the skull is decid 
edly convex, the zygomata are strongly decurved, and the outer angle is 
broadly expanded. Numerous other cranial differences exist, and it is 
probable that the castanops series will be eventually separated, at least 
subgenerically, from Cratogeomys proper. 


(1) Basioccipital )'w/rtHr/i«/«r, its sides parallel 

Rostrum and brain case long castanops 

Rostrum short ; brain case broad gohlinani 

(2) Basioccipital truncate wedge-shaped (sides approximating anteriorly), 
rt' Sagittal crest well devoloped. 

¥ Lower incisor strongly beveled on outer side merriami 

If Lower incisor not beveled on outer side. 

c' Top of skull strongly convex in i)rofile fulvescens 

c- Top of skull nearly dat in profile. 

Nasals normal (rather long and narrow) ])erotensi8 

Nasals short, narrow posteriorly and broad anteriorly estor 

a^ No sagittal crest.* 

Outer face of upper incisor strongly beveled oreocetes 

Outer face of upper incisor not beveled peregrinus 

* The only specimens seen of oreocetes and pe)-egrinua are females ; it is possible 
that the old males may have a crest. 



(PI. 2; pi. 10, fig. 5; pi. 13, fig. 4; pi. 11, (ig. 7; pi. 1.5, figs. (> ami 9; pi. 17, fig. 5; 
pi. 18, fig. 4; ].l. 19, fig. 6). 

Geornys merriami Thomas, Aunals & Magazine Nat. Hist., Ser. 6, Vol. xii, October, 
1893, 271-273. (Type in l^ritish Museum.) 

Type from "southern Mexico" — probably the Valley of Mexico. 

Geofp-aphic (listrUmtion. — South end of Valley of Mexico and adjacent 
mountain slopes from just below the lower edge of the lower pine belt 
up to an altitude of 10,000 or 11,000 feet; east to Atlixco (Puebla), north 
to Irolo (Hidalgo), and west to Lerma, in Toluca Valley (map 4, i). 

General characters. — Size largest of the genus Gratogeomys; tail and 
hind feet moderately haired but not so well covered as in G.fulvescens; 
skull massive; incisors huge. 

Color. — Upper parts dull chestnut brown, mixed with black-tipped 
hairs, varying to glossy slate black; underparts similar but paler; the 
rusty specimens have a dark patch around and behind each ear, which 
is not apparent in the slate-black ones. 

Granud characters. — Skull large and massive, the zygomatic arches 
widely spreading anteriorly and rapidly Jiarrowing posteriorly (pi. 2); 
incisor teeth larger and heavier than in any known Mexican species, not 
excepting Flatygeomys gymnurus ; anteroposterior diameter of incisors 
much greater than transverse; lower incisors with a strongly marked 
bevel on the outer side immediately behind the enamel; behind the 
bevel the tooth is abruptly narrower; outer edge of eimmel forming a 
conspicuous bead. In adult males the squamosals completely cover the 
parietals and meet in a median crest above the sagittal crest proper. 
The mandible of the Lerma skull (No. 50110) is longer and narrower 
across the angular processes than that of specimens from the slopes of 
the Valley of Mexico. Skulls from Irolo differ from the typical form of 
the Valley of Mexico in having the mastoids considerably larger and 
fuller posteriorly, occupying more of the occipital plane. The audital 
bullae also are somewhat more swollen. The mastoids do not extend 
out so far laterally as in typical merriami; the postpalatal pits are not 
so deep; the coronoid processes of the mandible are more spreading 
(directed more strongly outward), and the heel of the last upper molar 
is shorter. The Irolo skulls agree with typical merriami and differ from 
the Atlixco specimens in having the frontal reach further forward along 
the median line than on the sides. Skulls from Atlixco differ from t^'pi- 
cal ?He>Tia'Wuntlie following particulars : The nasals extend farther back, 
reaching or passing plane of frouto-maxillary suture; the frontal 
reaches as far forward laterally as on median line (in merriami it resiches 
much further forward on median line) ; as a rule the coronoid processes 
of mandible are lower and more abruptly curved backward, with the 
coronoid notch correspondingly narrower. 

The massiveness of the incisor teeth in true merriami is much more 
extreme than in any of the other species, and is coihdinated, as already 


poiuted out, with ;i much greater development of tlie squamosal and of 
the various prominences and ridges for muscular attachment. 

Variations in pelage. — Gratogeomi/.s merriami exhibits both the melan- 
istic and chestnut color phases, and also intermediate pelages. In four 
adult specimens from Tlalpam, three are dark brown, faintly washed 
with fawn color or very pale fulvous; the fourth is bright chestnut or 
reddish-brown on the rump and sides, while the newer hair of the back 
is intimately mixed with blackish. One specimen from Amecameca 
has a white spot above the tail, as in the Irolo specimens. 

All of the three specimens from Irolo have an irregular white patch 
at the base of the tail above, and one has a small irregular patch on the 
rump and another on the belly between the hind legs. 

In the Irolo specimens the tail is less hairy and the hind feet more 
hairy than usual, and the hairs of the hind feet are white. 

One of the eight specimens from Atlixco has the white spot at the 
base of the tail, though not so large as in the Irolo and Las Vigas speci- 
mens. The hind foot is scant haired in the Atlixco specimens, which 
peculiarity is jirobably seasonal, since the Atlixco specimens were col- 
lected in July, while those from Irolo were collected in March. The 
tails are less hairy than usual in the Irolo and Atlixco specimens. 

Measurements (taken in flesh). — Average of 11 males from the south 
end of the Valley of Mexico and adjacent slopes (Amecameca, Tlalpam, 
Ajusco, Salazar, Huitzilac, and Lerma) : Total length, 380 ; tail vertebme, 
112; hind foot, 50. Average of 7 females from same localities: Total 
length, 344; tail vertebrae, 105; hind foot, 46. 

For cranial measurements see Table D, p. 210. 

Speeinie)is examined. — Total number 31, from the following localities: 
State of Mexico, Tlalpam, 4; Amecameca, 9; Ajusco, 2; Salazar, 1; 
Lerma, 1; State of Morelos, Huitzilac, 3; State of Hidalgo, Irolo, 3; 
State of Puebla, Atlixco, 8. 

General remarks. — Mr. Nelson states that this large and j)owerful spe- 
cies is common in the south end of the Valley of Mexico, where it inhabits 
the soft soil of the bordering slopes and ranges on the west, south, and 
east sides of the southern two-thirds of the basin. Owing to the hard 
rock and clayey character of the middle and northern parts of the 
valley it does not occur there. On the west side it ranges up to the 
summit of the Sierra de Las Oruces (where he secured a specimen at an 
altitude of 11,000 feet near Salazar), and thence down the west slope 
into the border of the valley of Toluca, where a specimen was taken at 
Lerma. South of the Valley of Mexico it ranges up over the Sierra de 
Ajusco to an altitude of 10,000 feet, and across to Huitzilac on the 
south slope within the borders of the state of Morelos. On the east 
side of the valley it ascends the basal slopes of Mounts Popocatapetl 
and 1/taccihuatl. On the southeast slope of Poi)ocatapetl it occurs at 
Tochimilco and on the adjacent plain about Atlixco, Puebla. It was 
also found at Irolo, Hidalgo, at the extreme north end of tlie Sierra 


Nevada de Iztaccihuatl. Wherever found in aiuriciiltiual land it is very 
destructive to (!orn, wlieat, an<l other crops. 

('RATO(}E()MY!S PEROTENSIS sp. iiov. 
( PI. 8, ii-r. fi. ) 

Type from Cofre de Perote, Vkua Cuu/ (altitude l),r>00 feot). No; 54299 9 ad. 
U. S. Nat. Museum, Departmeut of Agriculture collection. Collected May 28, 
1893, by E. W. Nelson. (Original No., 4889.) 

Geographic distribution. — Cratogeomys perotensis inhabits the west 
and higher slopes of the Cofre de Perote, which are wooded, and prob- 
ably descends to the northward to meet tlie range of C. estor. Mr. 
Nelson's specimens were obtained at the altitudes of 0,500 and 12,000 
feet (map 4). 

General characters. — Size rather large (smaller than merriami but 
larger than estor); no naked nose pad; hind feet and tail rather well 

Color. — Upper parts dark russet fulvous, everywhere finely mixed 
with black-tipped hairs; a small dusky patch behind each ear; an 
irregular white patch at base of tail in some specimens (in eight out of 
thirteen); under parts dark plumbeous, more or less washed with 
fulvous; hind feet usually dark proximally and white distally, but 
sometimes all white (and not always symmetrical on the two feet). Not 
one of the thirteen specimens is in the slaty- plumbeous ijelage so com- 
mon in G. merriami. Tliis species has the tail more hairy than in the 
others of the merriami series, and in a number of specimens it is irregu- 
larly blotched with dusky and white, a iieculiarity not observed in any 
other species. 

Cranial characters. — Unfortunately the maleoH perotensis is unknown,* 
all of the thirteen specimens collected by Mr. Nelson on the Cofre de 
Perote being females. The skull of the female, however, furnishes 
excellent characters. It agrees witli merriami in general form, in 
having the i)rofile of the top of the skull a nearly straight line (not 
convex as in fulvescens and castanops) and in having a well developed 
sagittal crest. Whether or not the S(juamosals completely overlap the 
parietal in the adult male, as they do in merriami, is not known, but 
they probably do. Aside from its much smaller size, the skull of the 2 
perotensis may be distinguished at a glance from that of merriami, and 
from all other known species of Cratogeojnys, by the slender ness of the 
jugal anteriorly. The jugal is not at all enlarged anteriorly, and is 
deej^ly mortised into the maxillary arm of the zygoma (see pi. 13, fig. 5)« 

* Unless one of the specimens obtained near Las Vigas (No. 54311) belongs to this 
species instead of estor. It is an immature male, too young to place the identity 
beyond question, but has the characters a young male perotensis would be expected 
to possess. The skull as a whole is larger than the adult female o{ perotensis (and 
hence considerably larger than estor); the rostrum and nasals arc longer; the jugal 
is broader anteriorly, and the si|uamos:ils have already crei>t up over part of the 
parietals and would undoubtedly meet in advanced age. 


111 some instances the squamosal arm of the zygoma reaches so far for- 
ward and the maxillary arm so far backward that the two nearly meet 
above the jugal. The nasals end on or near the plane of the front of 
the zygoma, and the ascending branches of the premaxilla reach back 
past the plane of the lachrymals, thus leaving a long median projec- 
tion of the frontal between the hinder ends of the premaxillaries. 
Skulls of jyerotensis may be distinguished from those of estor (from the 
lower northeast slopes of the same mountain) by larger size, much 
greater length of rostrum and nasals, slenderness of Jugal anteriorly, 
greater length of sagittal crest, and by the form of the frontal between 
the orbits, which is broadly rounded instead of flat. 

Measurements (taken in flesh). — Type : Total length 300; tail vertebrpe 
79; hind foot 40. 

Average measurements of twelve females from type locality: Total 
length 310; tail vertebra) 88 ; hind foot 41.5. 

For cranial measurements see Table D, p. 210. 

Specimens examined. — Thirteen, all from Oofre de Perote, Vera Cruz. 


(PI. «, figs. 4 and 5.) 

Type from Las Vigas, Vera Cruz (altitude 8,000 feet). No. 54308 ^ ad. U, S. Nat. 
Museum, Department of Agriculture collection. Collected June 12, 1893, by E. 
W. Nelson. (Original No. 500.5. ) 

Geograpliic distribution. — The pine-covered hills and flats forming 
the extreme northeastern foothills of the Cofre de Perote, and also 
the belt of i)ine forest connecting the timber of the mountain witli the 
wooded hills of the north. Its range is chiefly east and north of that 
of perotensis. G. estor thus reaches the extreme eastern edge of the 
table-laud. Mr. Xelson's specimens were obtained at an altitude of 
about 8,000 feet (map 4, k). 

General characters. — Size medium (smaller than perotensis); naked 
nasal pad small or absent; hind feet and tail rather well haired, as in 

Color. — Upper parts dark russet fulvous, everywhere finely mixed 
with black-tipped hairs; a small dusky patch behind each ear; an irreg- 
ular white patch at base of tail above (on all ten specimens) and some- 
times one below also; under parts dark plumbeous, more or less washed 
with fulvous; hairs of hind feet whitish, usually to ankle. Not one of 
the ten specimens is in the melanistic or slaty-pluinbeoiis pelage so 
common in merriami. 

Cranial characters. — Skull similar to that of perotensis in general form 
and profile, the top of the skull a nearly straight line — not strongly 
convex as in fulvescens and castanops. Contrasted vf\t\i perotensis (the 
only species witli which it requires comparison) G. estor ditters in the 
following characters: Size smaller ( <? of estor about equaling 9 of 
perotensis); rostrum much shorter; nasals shorter ami broader ante- 


lioily; juji'al broader anteriorly and less deeply i^mbeded between forks 
of maxillary arm of zygoma; frontal broader iiiterorbitally on top of 
skull, and tiat instead of broadly rouuded; sagittal crest shorter ante- 
riorly and perhaps not present iu the female. The female with distant 
temporal impressions (No. 54300) figured on pi. 8, fig. 4, is not fully 
adult; in advanced age the sagittal area is probably nearly or quite 
obliterated by union of the temporal ridges. 

Measurements (taken in flesh). — Type ( £ ad.): Total length 315; tail 
vertebme 94; hind foot 41. 

Average measurements of four males from type locality: Total length 
313; tail vertebnp. 89; hind foot 42. 

Average measurements of four females from same place: Total 
length 277 ; tail vertebra? 75 ; hind foot 37. 

For cranial measurements see Table D, p. 210. 

Specimens examined. — Ten, all from Las Vigas, Vera Cruz. 

General remarks. — C. estor resembles C. perotensis so closely in color 
and external characters that the two are practically indistinguishable 
except in size, estor being decidedly the smaller. In cranial characters, 
however, they are quite distinct, as pointed out above. 

Mr. Nelson states that wherever the pine forests are cleared away 
and the ground cultivated within the range of this species, the animal 
nuiltiplies rapidly and becomes exceedingly destructive to crops. 


(PI. 8, figs. 1 and 2.) 

Typo from Mount Popocatapetl, Mexico (altitude, 11,000 feet). No. 57963 9 yg. 
ad. U. S. National Museum, Department of Agriculture collection. Collected 
January 7, 1894, by E. W. Nelson and E. A. Goldman. (Original No. 47.) 

Geographic distribution. — The boreal higher slopes of Mount Popo- 
catapetl, above the range of Cratogeomys merriami (abo/e 11,000 feet 

General characters. — Incisor sulcus broadly open and wholly on inner 
side; size rather large; pelage soft; nasal pad small; hind feet and tail 
sparsely haired. 

Color (of type specimen). — Dusky, darkest on head and along median 
part of back; tips of hairs washed with i^ale brown; a golden brown 
patch under each eye; forefeet dusky ; hind feet white. Apparently 
the specimen is just beginning the change from the plumbeous to the 
brown pelage. 

Cranial characters. — Zygomatic arches narrow, their sides nearly par- 
allel; anterior angle moderately expanded (about as iu Heterogeomys 
/tis/>?rfws); temporal ridges strongly developed; nasals wedge-shaped, 
not inflated anteriorly, ending posteriorly in front of jflane of anterior 
face of zygoma; ascending branches of premaxiila just reaching plane 
of orbit, not divaricating behind nasals; frontal flat (orbital edge 
rounded), rather broad interorbitally and posteriorly, reaching forward 


between premaxillte much further than laterally; supraorbital promi- 
nences not strongly developed; temporal ridges anterior to interpari- 
etal straight, inclosing an elongated wedge-shaped interspace (but very 
diiierent from the interspace between the strongly curved ridges of 
H. hispidus)', interparietal elongated autero posteriorly, very much 
longer than broad; jugal long and large, forming an important part of 
arch; lambdoid crest strongly and evenly convex iiosteriorly ; occipital 
plane flat, sloping slightly forward from below upward ; j^osterior ends 
of palatals excavated laterally; pterygoids uarrow linguhe with parallel 
sides, as in C. merriami; audital bulhe relatively short and swollen, 
more subglobular than in H. Jmpidus; brain (;ase rising abruptly from 
posterior roots of zygomata, much as in hispidus (not flatly rounded as 
\\\i\x<A merriami group and in peregrinus). Under jaw short and rather 
narrow, as in hispidus; angular processes short. 

Dental characters. — Face of upper incisors unisulcate, the groove 
wholly on inner side and broadly open, as in merriami — not narrow and 
deep as in H. hispidus and M. heterodus; breadth of enamel face of upper 
incisor slightly greater than anteroposterior diameter of tooth; outer 
side of tooth strongly beveled immediately behind enamel, as in the 
lower incisor of merriami. Lower incisor narrow, the transverse diame- 
ter less than the anteroposterior. Crown of last upper molar much 
broader than long; no distinct heel ; the inner side convex, the outer 
side eniarginate and longer. The curvature of the prism of this tooth 
is much less than in the merriami series and less than in H. hispidus. 

The premolar is the longest tooth and is slightly convex anteriorl}^; 
ni' and m^ are hardly shorter and are subequal (or nV^ maybe slightly 
the shorter); both are strongly convex anteriorly; m^ is more than 
two-thirds the length of m'^ and is only moderately convex anteriorly. 

ilAeaswremew/s (taken in flesh). — Type specimen: Total length, 318; 
tail vertebrfB, 91'; hind foot, 43. 

For cranial measurements see Table D, p. 211. 

General remarks. — Cretogeomys oreocetes does not require close com 
parison with any known species. From its nearest neighbor of the 
lower slopes of the same mountain {C. merriami) it differs conspicuously 
in smaller size, narrower zygomata, shorter and more globular audital 
bullip, and in the presence of strongly developed temi^oral ridges. 

From C. peregrinus, which inhabits the corresponding boreal slopes 
of the neighboring mountain, the lofty Iztaccihuatl, it may be distin- 
gnished by its narrower and higher craninm, by the beveled outer face 
of the upper incisor, the convex (instead of notched) inner border of 
crown of last upj)er molar, and other characters mentioned under that 

The measurements of the sknll of C. oreocetes (see table D) show that 
the posterior breadth of the cranium is nearly equal to the zygomatic 
breadth. This is due to the narrowness of the zygomatic arches — not 
to any unusual breadth of the cranium posteriorly. 



(I'l. S, fijr. 3.) 

Ty]tc from Mount IzTACCiiirATL, Mexico (altitude 11,500 foet). No. 57964 9 old. 
U. >S. National Museuiu, Department of AgTiculture colh^ction. Collected Jan- 
nary 9, 1894, by E. W. Nelson and E. A. Goldman. (Original No. .50.) 

Geographic distribution. — The boreal liiglier vslopes of Mount Iztacci- 
biiatl, above the rauge of (Jratogeomys merriami (above 11,500 feet alti- 

General characters. — Size medium or rather large; hind foot and tail 
scant haired; nasal pad small; forefoot large (with claws nearly equal- 
ing hind foot with claws). Color i^eculiar. 

Color (of type and only specimen). — Steel gray from the intimate 
adnnxture of dusky and whitish hairs; under parts paler than upper; 
thjoat, sides ot face, and fore feet darker. The hairs of the hind foot 
are whitish ; of the tail dusky. 

Cranial characters. — The skull of the type, a very old female, has the 
posterior part of the cranium very Hat and broad, and the zygomata 
broad and bowed outward, suggesting Flati/geomys fiimosus. In other 
respects the resemblances are more in the direction of Cratogeomys 
merriami, with a few characters pointing toward Heterogeomys. The 
zygomatic arches are widely spreading, not divergent anteriorly but 
broadest across the middle (breadth anteriorly slightly less than great- 
est breadth of squamosals jjosteriorly) ; tlie anterior roots stand out at 
nearly a right angle; the antero-external angle is moderately expanded 
and sharply angular when seen from the side; rounded as seen from 
above. Thejugal is rather large and forms an important part of the 
arch as in C. merriami. The muzzle and nasals are short, the latter 
broad anteriorly and truncated posteriorly about on the plane of the 
anterior face of the zygomata. The ascending branches of the premax- 
illa are broad and blunt ^posteriorly, barely reach the plane of the 
orbits, and do not approximate or divaricate behind the nasals. The 
frontal reaches furthest forward along the median line; the suture at 
base of maxillary root of zygoma (on top of skull) is nearly a straight 
line. There is no sagittal crest, but the temporal ridges approximate 
immediately in front of the interparietal, from which jDoint they divar- 
icate in both directions; anteriorly they slope slightly outward in nearly 
a straight line to a point about opposite the i^osterior part of the post- 
orbital prominences of the frontal where they become less distinct 
and curve abruptly outward. The iutersi^ace is an elongated wedge, 
as in C. oreoeetes, and is not depressed below the level of the temporal 
ridges, a result perhaps of the extreme age of the animal. In shape 
it differs widely from that of the genus Heterogeomys. The great 
breadth of the cranium i)osteriorly is due to lateral expan.sion of the 
squamosals, as iu Platygcomys. The greatest breadth across squa- 
mosals (over mastoids) is slightly greater than the zygomatic breadth 
anteriorly. The interparietal is not covered by the parietals and is 


elongated aiitero-posteriorly. The plane of the occiput is moderately 
smooth and slopes forward; it is low and broad, the breadth being 
about two and-a half times the height. The mastoid bulhe are much as 
in merriami, except that the inferior border is shorter and the inner side 
is armed Avith a short blunt spine projecting inward and slightly back- 
ward. (This may be abnormal, but the points are symmetrical on the 
two sides.) The audital bulhe are rather short and tumid (much as in 
oreocetes) and the anterior projection which abuts against the basi- 
sphenoidis sharply set oft' by a deep notch on the upper side. The palato- 
pterygoids are lingulate, slightly broader than in merriami, the sides 
nearly parallel ; mandible short and narrow, resembling that of oreo- 
cetes, from Avhich it ditters in having the angular processes even shorter 
and the coronoids more hooked. 

Dental characters. — Upper incisors with a single very broad and open 
groove (broader even than in oreocetes), its deepest point on the iuaer 
side of the median line; breadth of enamel face greater than antero- 
posterior diameter of tooth. Lower incisors narrow, the breadth of the 
enamel face being considerably less than the anteroposterior diameter 
of tooth. Crown of last upper molar not distinctly heeled, its inner 
border about half the length of outer and deeply notched; outer side 
broadly concave. 

Measurements (taken in flesh). — Type specimen : Total length, 304; tail 
vertebra^, 87 ; hind foot, 42. 

For cranial measurements see Table J3, p. 1*11. 

(PI. 12, iig. 1; pi. l.S, fig. 17: pi. U, fig. 6.) 

Pseudostoma castanops Baird, Report Stansbury's Exp'd. to Great Salt Lake, June 
18.52, 313. (Type from near Bents Fort, Colorado.) 

Geomys castanops Baird, Mammals of North America, 1857, 381-386. 

Geomijs clarUi Baird, Proc. Acad. Nat. Sci., Phila., vii, 18.5.5, 332. (Ty])e from Pre- 
sidio Del Norte, on tlie Rio Grande, Chihuahua, Mexico.) 

Type locality: " Prairie road to Bents Fort," near the present town 
of Las Animas, Colorado, on the Arkansas Eiver. (Type in U. S. 
National Museum.) 

Ueographic distribution. — Isolated areas on the Great Plains from 
the Arkansas River in Colorado, southward through eastern New Mex- 
ico (west to Albuquerque), and western Texas to Santa Rosalia, Chi- 
huahua, and Jaral, Coahuila (map 4, h). 

General Gharacters. — Size, medium; coloration, yellowish-brown; tad 
of medium length; rather scant haired. 

Color. — Upper parts yellowish brown or buffy ochraceous tinged with 
yellowish, more or less mixed with black- tip])ed hairs, which are much 
more numerous in winter pelage; under parts butfy. 

Cranial characters. — Skull very broad and heavy; zygomatic arches 
widely spreading anteriorly and strongly decurved; profile of skull 
convex on top; end of maxillary root of zygoma greatly expanded, 


forming a broad plato, into which the euhirged head of the Jugal is 
received; sides of basioccipital parallel. C. castanops differs from C. 
fulvesccns m havinij tlie basioccipital narrow, its sides excavated and 
j)arallel ; the nasals and nasal branches of the premaxilla more produced 
posteriorly; the hitter cutting the plane of the orbits, and in lacking 
the thickened sockets of the upper incisors. 

Measurements (taken in flesh.) — An adult male from Las Animas, 
Colorado (practically type locality): Total length, 295; tail vertebrae, 
95; hind foot, 37. 

Average of 3 females from same locality: Total length, 256; tail 
vertebra', 77 ; hind foot, 33. 

For cranial measurements see Table D, p. 211. 

Specimens examined. — Total number 43, from tlie fcdlowing localities: 
Olney, Colorado, 2; Las Animas, Colorado (type locality), G; Chico 
Springs, New Mexico, 2; Albuquerque, New Mexico, 3; Eddy, New 
Mexico, 3 ; Sierra Bianca, Texas, 1 ; Marfa, Texas, 3 ; Eagle Pass, Texas, 
13; Samalayuca, Chihuahua, Mexico, 2; Gallego, Chihuahua, Mexico, 2; 
Santa Rosalia, Chihuahua, Mexico, 4; and Jaral, Coahuila, Mexico, 5. 

General remarks. — Coues has already shown that clarTcii can not be 
distinguished from castanops, and the examination of a much larger 
series than heretofore available confirms this determination. The 
peculiar line of demarkation in the type specimen* described by Baird 
as separating the color of the head and neck from that of the rest of 
the upi)er parts, is now well known as the molt line (which progresses 
from before backward) ; and the alleged differences in the feet and skull 
donot hold good in the ample series (forty-three specimens) now at hand. 
The species i^resents considerable geographic variation in size (mostly 
sporadic), as usual in members of the family having an extensive range. 
The only notable departure from the type observed in the present series 
is in two specimens from Chico Springs, N. Mex. These specimens are 
smaller than the type form, brighter and more ' yellowish-chestnut' 
in color, and the fore feet, hind feet, and tail are distinctly blackish. 
The tail furthermore is well covered with hair for its entire length. 

Mr. Vernon Bailey tells me that Gratogeomys castanops is a very inju- 
rious species to orchards and nurseries. Along' Onion Creek, 30 miles 
southwest of Marfa, in Presidio County, Texas, he found them eating 
the roots of fruit trees where "two or three soon sjioil an orchard if 
left in it; the owners did not know how to get rid of them." 


Type from. Canitas. Zacatecas, Mexico. No, 57965 9 yg. ad. U. S. National Museum, 
Department of Agriculture collection. Collected December 24, 1893, by E. A. 
Goldman. (Original No. 286.) 

* The type specimen, formerly in the Patent Office, is now in the National Museum, 
but is in very poor condition, ha\'iug been exposed to the light for nearly forty years, 
as a result of which it is so faded that no trace of the original color remains. 


General characters, — Similar to C. castaiiops in size and external 
appearance, but differing in cranial characters. Tail and hind feet 
rather well haired for a Pocket Gopher. 

Color. — Upper parts dull butiy-ochraceous, moderately mixed with 
black- tipped hairs; under parts paler. 

Cranial characters. — Unfortunately all of the five specimens at hand 
of this form are females. Compared with females of C. castanops the 
skulls diHer in being- broader, shorter, and flatter, with less decurved 
zygomata, and decidedly shorter and broader nasal bones. The short- 
ening is chiefly in the rostrum; the broadening chiefly in the brain 
I case. The basioccipital averages longer and somewhat larger and its 
' sides are less truly parallel, being a little broader jjosteriorly than 
anteriorly. The plane of the occiput is narrow and much elongated 
transver.sely. The coronoid process of the mandible is long, depressed, 
and reaches far back. 

Measurements (taken in flesh). — Type: Total length, 270; tail verte- 

I brje, 90; hind foot, 35, 

Average measurements of three females from type locality: Total 
length, 257; tail vertebrie, 83; hind foot, 34.3. 
For cranial measurements see Table D, p. 211. 
Specimens examined. — Total number 5, all from Oaiiitas, Zacatecas. 


(PI. 12, fis. 2.) 

Type from Chalchicomula, State ok Pueisla, Mexico. No. 58168 <? ad. U. S. 
Natioual Museum, Department of Agriculture collection. • Collected January 
15, 1894, by E. W. Nelson and E. A. Goldman. (Original No. 5651.) 

I Geographic flistrihution. — The basin-like plain of eastern Puebla, 
Mexico, from Esperanza north to Perote and west to the northeast 
base of Mount Maliuche in Tlaxcala (map 4, j). 

General characters. — Ui^per incisors unisulcate; forefeet shorter than 
hind feet. Similar in general ap])earance to G. castanops, but larger; 
color darker; tail rather longer, darker, and slightly more hairy. 

Color. — Upper parts grizzled yellowish brown, liberally mixed with 
dark-tipped hairs; under parts buffy-fulv^ous or ochraceous-bufl'. Com- 
pared with castanops the general color is darker, owing to more bounti- 
ful admixture of dark-tipped hairs. 

Cranial characters. — Skull rather massive; zygomata squarely S])read- 
ing, angles broadly expanded; alveoli of upper incisors thickened; 
profile of top of skull very convex ; rostrum decurved anteriorly. 

The fronto-maxillary suture is peculiar, its anterior end usually 
reaching or nearly reaching the plane of the front of the zygoma — in 
all the allied species the frontal ends about opposite the middle of the 
anterior root of the zygoma. 
7433— :No. 8 11 


The lieigbt of the roof of the cranium above the palate, and of the 
brain case above the posterior roots of the zygomata, are much greater 
than in any other member of the genus, and the breadth of the skull 
posteriorly is much less. 

Contrasted with C. castanops the skull of fulvescens differs in the fol- 
lowing particulars: size larger; rostrum broader; sockets of upper 
incisors thicker, bulging externally; nasals and ascending branches of 
l^remaxilla shorter i^osteriorly, the former hardly reaching plane of 
front of zygoma, the latter not reaching jilane of orbits; basioccipital 
much broader and wedge-shaped, as usual in the genus (in castanops 
the basioccipital is narrower and its sides are parallel, see pi. 12, flgs. 1** 
and 2^). 

MeasuremenU (taken in flesh). — Type specimen ( t? ) : Total length, 
318; tail vertebra^, 102; hind foot, 43.5. 

Average of three males from type locality : Total length, 327 ; tail ver- 
tebra?, 105; hind foot, 43. 

Average of six females from type locality: Total length, 302; tail ver- 
tebra?, 97 ; hind foot, 30.0. 

For cranial measurements see Table I), p. 211. 

Specimens examined. — Total number 11, from the following localities: 
Chalchicomula, Puebla, 9; Perote, Vera Cruz, 2. 

General rem^arlcs. — C. fulvescens does not require close comparison 
with any known species except C. castanops, which it resembles in the 
grizzled yellowish-brown color of its upper parts. It is more fulvous 
than castanops, from which it difl'ers further in larger size and in the 
cranial characters above i)ointed out. Specimens from Perote are more 
-ellowish and less fulvous than those from Chalchicomula. 

Mr. Nelson states that this species inhabits the sandy open i)lain from 
an altitude of 8,000 feet in the lower parts of the basin up to 9,000 feet 
on the west slope of Mount Orizaba. He states further: "In this dis- 
trict its range is almost identical with that of Dipoilomys phiUipsi. 
Like the latter species it follows up the cultivated land into the low^er 
border of the pine forest on Mount Orizaba, and is common also about the 
northeast base of Mount Malinche. These gophers are particularly 
numerous in cultivated ground, and are very destructive to corn and 
grain of all kinds." 

Genus PLATYGEOMYS " uob. 

( PI. 3; pi. 10, tig. 8; pi. 13, tigs. 1-3; pi. 14, tig. 9; pi. 15, tig. 7; pi. 17, tig. 4; pi. 18, 

fig. o; pi. 19, fig. 7.) 

Type Geomi/s (ji/mintnis Merriam, from Zapotlan, Jalisco, Mexico. 

Dental characters. — Upper premolar Avith three enamel plates (the 
posterior absent), its shaft nearly straight. First and second upper 
molars with one enamel plate each (posterior absent). 

* PJatijgeoniijs, from TrXatvi, broad, wide, + Geomys, with reference to the great 
breadth of the cranium. 


Third upper molar an incomplete double prism, the outer side abruptly 
narrowed behind the anterior prism; axis of heel anteroposterior; 
inner enamel plate nonnally less than two-thirds as long as anterior 
plate; not covering posterior face of tooth; outer plate normally as long 
as inner and usually reaching posterior edge of heel. 

Upper incisor strongly unisulcate^ the sulcus median or slightly on 
inner side (fig. 2P). 

Cranial characters. — Skull large, heavy, and flat; hinder part of 
cranium extraordinarily broad and flat, the great breadth due chiefly to 
lateral expansion of the squamosals, which not only project as a thin 
shelf beyond the brain case, increasing the size of the glenoid fossa 
both anteriorly and posteriorly, but also completely arch over and 
conceal the postglenoid notch, curving with only a shallow con- 
cavityfrom the posterior angle of the zygomatic arch to and beyond 
the extreme tip of the transversely elongated mastoid; zygomatic 
arches massive, broadly spreading anteriorly, the antero-external angle 
expanded vertically into a triangular plate between the strongly pro- 
duced and decurved external angle and the evenly rounded orbit (the 
resulting plate made up in part of the distal end of the maxillary arm 
of the arch, and in part of the anterior end of the jugal, which is 
usually expanded); jugal normally large and broad, forming an impor- 
tant part of the arch; pterygoids vertical lamelhe with inferior border 
everted; orbitosphenoids larger than in Cratof/eonii/s but not normally 
articulating with alispheuoid; mesethmoid a little more than a half 
crescent, its anterior border strongly rounded above (pi. 18, fig. 5); 
endoturbinals together forming an elongated oblique plate which is 
sharply pointed antero-superiorly, owing to the elongation of the upper 
endoturbinals (pi. 19, tig. 7) ; no extension of os planum in front of lower 
endoturbinals and no curving down of vomerine edge of os planum 
below ijlane of roof of narial passage; floccular fossa ill defined and not 
separated from internal auditory meatus by a distinct ridge; ridge 
separating superior from inner surface of petrous only feebly developed 
(pi. 17, fig. 4; and pi. 18, fig. 5). 

In addition to the above-described generic characters, most of which 
are in strong contrast to those of Cratogeomys, the following points are 
selected with special reference to antithesis with Crafof/eomyfi (which 
see) : Breadth of cranium posteriorly (above mastoids) equal to or 
greater than greatest zygomatic breadth ; breadth of occipital plane at 
least two and a half times its height ; lambdoid crest sinuous, presenting 
three posterior concavities; squamosal expansion chiefly away from 
median line — not covering inner part of parietals; mandible very much 
broader than long* (including incisors); angular processes of mandible 

* The extraordinary breadth of the mandible across the angular processes is not due 
alone to the great length of these processes, but in part to tlieir position. They 
are higher and more nearly on a level with the mcisor protuberance than in any 
other torm, and the jaw as a whole is Hatter. 


extraordinarily long and spreading, reaching ont so far laterally that 
the knob over root of incisor is midway between condyle and end of 
angular process fpl. 3) ; squamosal arm of zygoma covering about half 
(iu fumosus more than half) of upper edge of jugal, which latter enters 
broadly into formation of zygomatic arch; free part of upper edge 
of jugal equal to length of basioccipital on median line (except ni 
fufnosus); paroccipital processes large and expanded, forming recurved 
flanges; incisors slender in contrast to those of the merriami series; 
anteroposterior and transverse diameters of incisors subequal ; enamel 
face of lower incisors forming an inconspicuous bead on outer side of 
tooth, behind which the tooth is not beveled, the transverse diameter 
through the enamel face being inappreciably greater than posteriorly. 


1" Zygomatic arches parallel or hatred outward in the middle fumosus, 

1" Zygomatic arches strongly divergent anteriorly: 

Jugiil only slightly expanded auteriory planiceps. 

Jugal broadly expanded anteriorly : 

Nasals strongly wedge-shaped; narrow posteriorly; reaching 

plane of zygoma gymnurus. 

Nasals not wedge-shaped; broad posteriorly; not reaching 

plane ol zygoma tylorh inus. 


(Pl.3; pi. 10, fig. 8; pi. 13, fig. 2; pi. 15, fig. 7; pi. 17, fig. 4; pi. 18, fig. 5; pi. 19, fig. 7.) 

Geomys gymnurus Merriam, Proc. P.iol. Soc. Washington, vii, Sept. 29, 1892, 166-167. 

Tyjie locality. — Zapotlan, Jalisco, Mexico. (Type in U. S.ISratioual 

Geographic distrihution. — Valley of Zapotlan and adjacent slopes of 
the Sierra Nevada de Colima, Jalisco, and the volcano of Colima down 
to the upper edge of the plain of Colima, Mexico. 

General characters. — Size very large; a naked pad on end of nose; 
tail naked; feet sparsely haired; hinder part of cranium extraordiua. 
rily broad. 

Color. — Upper parts dark reddish-brown or chestnut, varying to sooty 
plumbeous or slate-black, slightly paler below. The rusty specimens 
have a dusky xiatch about each ear and a larger one on the nose. The 
depth of the chestnut seems to increase with the age of the hair, speci- 
mens in the molt having the new hair very dark and only washed on 
the tips with chestnut. The hairs of the hind feet are scattered and 
nearly colorless. Tlie young are glossy slate-black, with the sides and 
rump consi)icuously sprinkled with whitish bristles. 

Cranial characters. — The skull of Platygeomys f/ymnurus differs from 
all others of the family (except the related P. tylorhinus and planiceps 
here described) in the extraordinary breadth and flatness of the hinder 
l^art of the brain case, the result of lateral exj)ansion of the squa- 


raosals, which completely arch over and conceal .the postglenoid notch, 
curving with a shallow concavity from the posterior angle of the zygo- 
matic arch to the extreme tips of the transverely elongated mastoids, 
which they overreach. The breadth of the cranium here equals or 
exceeds the greatest zygomatic breadth. Corr elated with this unpre 
cedented breadth of the posterior part of the cranium is an even more 
extreme lateral extension of the angular processes of the mandible. 
The zygomatic arches are widely spreading anteriorly, with broadly 
expanded subtriangular outer angles. The jugals are large, broadly 
expanded anteriorly, enter largely into the outer wall of the orbital 
fossa, and, as a rule, terminate anteriorly in a straight edge, which 
articulates witli the lower third of the ascending or maxillary arm of 
the zygoma without being mortised into it as usual in the group; 
still the front of the jugal rests on a strong shelf of the maxillary 
arm, and is commonly overtopped by a sliort spicule. The exposed 
part of the upper edge of the jugal forming part of the outer wall of 
tbe orbital fossa is usually, though not always, as long as the basi- 
occipital (on median line), and as a rule the posterior half of the jugal is 
overlapped by the squamosal arm of the zygoma. Tlie fronto-maxillary 
suture is straight or slightly convex outward, while its continuation as 
the premaxillo-maxillary suture (on top of the skull) is strongly con- 
cave inward, the result being that the suture at the base of the maxil- 
lary arm of the zygoma, taken as a whole, is shaped like the letter S 
somewhat drawn out. In tylorhinus and planiceps it is broadly and 
uniformly convex inward. The nasals end posteriorly on or a little 
behind the anterior plane of the zygoma, and are strongly wedge- 
shai^ed and much narrower posteriorly than in tylorhinus. The nasal 
branches of the j)reniaxilla may or nmy not reach the plane of the 
orbits; they a])proximate slightly behind tlie nasals, « 

The occipital plane is exceedingly broken and irregular; the lamb- 
doid crest overhangs it as a sinuous ledge throughout its entire 
lengtli; the greatly enlarged paroccipital processes stand out like 
broad flanges from the exoccipitals, projecting strongly outward and 
backward, forming, in conjunction with the middle part of the lamb- 
doid crest, a remarkable basin-shaped inclosure, outside of which, and 
far anterior to the great paroccipital flanges, are the transversely- 
elongated mastoids (pi. 15, fig. 7). In striking contrast is the smoothly 
planed- off occiput of Heterof/eomys his2)i(lus (pi. lo, fig. 4). 

The shape of the lambdoid crest is peculiar; it is deeply sinuous, 
with three concavities directed forward (of which the median is deep, 
the lateral shallow), and two strong convexities directed backward; 
at each end it terminates in a club-shaped knob directed outward. 
Looking at the skull from above there is nothing to indicate the 
limits of the brain case, the broad squamosals being convex upward 
behind the zygomata, without trace of the lateral depression that 
marks off" the brain case in Cratogeomys and most other members of 
I the family. 


Measurcniciits (tiikeii.iii flesli). — Average of three males from type 
locality (Zapotlan, Mexico): Total leiigMi, o5li.G; tail vertebra', 105.3; 
bind foot, ~)3.'.'>. Average of three females from same place: Total 
length, 341; tail vertebne, 91 ; hind foot, 40.G. 

For cranial measurements see Table E, p. 211*. 

Specimens examined. — Total number, 10, from the following localities 
in Jalisco, Mexico: Zai^otlan, 7; Sierra Nevada de Colima, 3. 

General remarks. — Plati/f/eomys (jymnnnis may be regarded as the 
type (for it is the largest and most extreme in cranial peculiarities) of 
a remarkable series of Pocket Gophers inhabiting southern Mexico 
from the Sierra Nevada de Colima of Ja.lisco eastwarTl to the north 
slope of the Volcan Toluca in the State of Mexico, and Tula in 
Hidalgo. Externally these animals difler so little from the larger spe- 
cies of Gratof/eomys as to be distinguished with difficulty, but in cranial 
characters they may be told at a glance. The number of recognizable 
forms now known is four, of which one {fumosus) is very distinct from 
the others; the remaining three are closely related {(jyninurus, tylo- 
rliinns, and planiceps) and two of them {tylorhiniis and planiceps) may 
be found to intergrade when specimens are obtained from intermediate 
localities along the line of their distribution, in which event the latter 
must be reduced to subspecific rank. Still another form that might 
be deemed worthy of separation is the Patzcuaro animal mentioned 
under the head of P. tylorhinus. 

All the members of the gymnurus series have the upper parts more 
or less plentifully sprinkled with long, slender, bristle-like hairs which 
protrude far beyond the ordinary fur. In fumosus these hairs are very 
conspicuous, owing to the marked contrast of their whitish color with 
the blackish-slate of the body; the same is true of the young in {/ym- 
nurvs, but in the adult they harmonize so well with the prevailing 
reddish-brown or chestnut tints that they may be easily overlooked. 
They are most abundant in the Patzcuaro specimens of iylorliimis. 

Mr. Nelson states that the rangxi of Platygeomys {/ymnvrvs, so far as 
determined by him, is limited to the valley of Zapotlan and slopes of 
the Sierra Nevada de Colima and base of the adjacent volcano of Colima, 
and the immediate vicinity. On the north slope of the Sierra Nevada 
de Colima he found them up to an altitude of 11,000 feet, among the firs 
and alders, where a specimen was secured. Thence to the base of the 
mountain they are rather common on open grassy slopes, and range 
out over all of the adjacent valley of Zai)otlan. In this latter district 
they were usually found in fields, where they do much damage to corn 
and wheat. Zapotlan Valley has an altitude of about 4,500 feet, and 
is an open basin-like ijlain just below the pines and oaks of the moun- 
tains. On the extreme upper border of the phiin of Colima, near the 
southwest base of the volcano, at an altitude of about 3,500 feet, he 
saw numerous diggings of a gopher, which was probably this species. 




(PI. 13, fig. 1.) 
Type from TrLA, Hidalgo, Mkxico. No. 51883 <? ad. U. S. National Museum, Depart- 
ment of Agriculture collection. Collected March 13, 1893, by E. W. Nelson. 
(Original No. 4442.) 

Geographic distribution. — Tula, Hidalgo, and tbeiice southwesterly 
along the north slope of the Sierra Madre to the vicinity of Patzcuaro, 

General characters. — Size, large; tail nearly naked; a naked pad on 
end of nose; coloration dark. Similar to P. gymnnrus, hut smaller, 
with shorter and more hairy hind feet, which are distinctly white in 
contrast to dark of ankles and legs; .skull remarkably broad and flat, 
as in P. gymmirns. but lighter and differing further in important 

Color. — Upper parts chestnut or liver-brown, as in Geomyshursorius; 
under parts similar but slightly paler, the plumbeous showing through 
in places; legs and ankles ccmcolor with body; hind feet white in 

Cranial characters. — Skulls of P. tylorhinvs differ from those of 
P. (lymnurns in smaller size, narrower rostrum, and shorter nasals, 
which do not reach plane of zygomatic arches. The most conspicuous 
difference is in the shape of the nasals: instead of being wedge-shaped, 
as in fjymnnrus, they are much broader i)osteriorly and abruptly 
truncated behind, and the premaxilhe do not approximate behind 
them. The skull as a whole is much less massive and the maxillary 
arm of the zygoma less thickened than in gymnnrus. The jugal is 
enlarged throughout and expanded anteriorly into a broad plate which 
abuts against the sides of the maxillary part of the zygomatic arch, 
which latter is hardly excavated to receive it, sending out a small shelf 
below and a short spicule above, much as in gymnurus. The suture 
at the base of maxillary root of zygoma is broadly convex inward; in 
gymnurus it is shaped like a drawn-out S. As usual, the skull of the 
female is much smaller than that of the male, and the jugal is narrower. 

Measurements [t'A\L&\\ in flesh). — Type specimen, 5 ad.: Total length, 
345; tail vertebric, 100; hind foot, 45. Average of two 9 specimens 
from type locality: Total length, 298; tail vertebrae, 91.5; hind foot, 

For cranial measurements see Table E, p. 212. 

Specimens examined. — Total number 9, from the following localities 
in Mexico: Tula, in Hidalgo, 4; Patzcuaro, in Michoacan, 5. 

General remarlis. — Sjiecimens from Patzcuaro, State of Michoacan, 
are intermediate in size and form of nasals between gymnurus axid tyi)i- 
cal tylorhinns from Tula, but exceed the latter in the expansion of the 
jugal and whiteness of the hind feet. The hind feet are more hairy, 
and the ankles are dark plumbeous instead of chestnut, causing the 
white to stand out in stronger contrast. Skulls of the Patzcuaro 


.inimal differ further from those froui Tula in having smaller and shorter 
pterygoid lamelliie (as seen from the side), leaving more space between 
their posterior edge and the audital bullte. The posterior ends of the 
palatals are smaller, thicker, and have the outer edge straighter. In 
the Tula skulls the palatals are thinner and broader, with the outer 
edge irregularly sinuous. In the Patzcuaro animal the jugals are con- 
spicuously broader anteriorly than in those from Tula, but as in the 
latter they are much less expanded in the female than in the male. 

There is an average difference in external characters by which tlie 
Patzcuaro specimens may be distinguished from specimens from Tula 
and the Volcano of Toluca. They are darker and richer in color (the 
chestnut being more ferruginous), and the head is mainly slate black, 
more or less faintly washed with rusty. This color does not cover the 
head uniformly but is disposed in a tolerably regular pattern from 
which there is little variation in the series of specimens at hand. The 
slate-black covers the muzzle, reaching back along the median line as 
far as the plane of the eyes, and sends a broad arm backward on each 
side to the shoulders, inclosing the eye and ear. The chestnut of the 
back comes forward over the top of the head to about the plane of the 
eyes, and on the sides of the face below the eyes to and sometimes 
including the cheeks. Possibly there is something seasonal in this 
pelage; all of the Patzcuaro specimens were collected at the same 
time — the latter half of July. 

Mr. Nelson contributes the following information respecting the local 
distribution of P. iylorhinus: "I found this species common along the 
north slope of the mountains about Lake Patzcuaro and thence to the 
vicinity of Lake Cuitzeo, in Michoacan. All of this district lies in the 
zone immediately below the pines (from about 5,500 to 6,800 feet alti- 
tude), and is largely cultivated to wheat and corn. The gophers are 
particularly numerous in the fields, where they do considerable damage 
to crops. They range up into the lower border of the forest where 
Zygogeomys trichopns is found. Beyond Lake Cuitzeo no work was done 
to the northeast until Tula, Hidalgo, was reached. There these animals 
were found in small numbers at an altitude of about 6,000 feet, in tlie 
vicinity of the town. They were only noted about the borders of small 
basin-like sinks, where the land was under cultivation. Not being " 
numerous here their depredations in the grainfields were of little 
moment. The district from Lake Cuitzeo to Patzcuaro has a cool cli- 
mate, with abundant rains during the summer months. Tula lies in a 
much more arid and warmer zone." 


(PI. 13, fig. 3; pi. 14, fig. 9.) 
fAscomys mexicanns, Liclit., Brants Muizen, 1827, 27-31 (in part). 
Type from north slope Volcan Toluca, Mexico. No. 55906 ^ U. S. National Museum, 

Department of Agriculture, collection. Collected September 12, 1893, by E. W. 

Nelson. (Original No. 5466.) 

JAN., 1895.] 


Geographic lUstribution. — N'orthern and eastern slopes of tlie volcano 
of Toluca and adjacent part of tbe valley to the city of Toliica, from an 
altitude of 8,600 feet up to tbe vicinity of timber line. 

General characters. — Similar to I*, tiflorhinus, from wbicb it differs 
inappreciably in external appearance except in tbe greater lengtb of 
tbe tail. Ui)per incisors unisulcate; skull broad and flat; size large; 
tail nearly naked; a naked pad on end of nose; forefeet with claws 
shorter than bind. 

Color. — Upper parts chestnut, as in Ujlorhlnus from Tula; under 
parts similar but paler, the plumbeous basal fur showing through in 
places; legs and ankles concolor with body; hairs of hind feet whitish, 
but scant. Nose below eyes blackish ; a large blackish spot around each 
ear. One specimen is dark plumbeous, washed with chestnut, and has 
the head markings described under the Patzcuaro specimens of tijlor- 

Cranial characters. — Skull similar to that of tylorhinus, from which it 
differs chiefly in the form of the jugal bone, which is narrow throughout 
or very slightly expanded anteriorly — not broadly expanded as in 
tylorhinus. It differs further from tylorhinus in having the nasals less 
squarely truncate posteriorly (and ending about on plane of middle 
of maxillary root of zygoma); the ascending branches of premaxilla 
rounded posteriorly and ending near anterior plane of orbits — not 
passing nasals so far as in tylorhinus; the cranium very broad and 
flat; occipital plane more than two and a half times as broad as high. 
The rostrum is narrow, but not narrower than in some specimens of 
tylorhinus from Tula. 

Measurements (taken in flesh). — Type specimen $ : Total length, 372; 
tail vertebnie, 121 ; hind foot, 40. Average of two females from type 
locality: Total length, 336.5; tail vertebme, 100; hind foot, 43. 

For cranial measurements see Table E, p. 212. 

Specimens examined. — Three, all from the north slope of the Volcan 
de Toluca, State of Mexico. 

General remarlcs. — This animal may prove to intergrade with tylo- 
rhinus of Tula, in which case it must be reduced to subspecific rank. 
The number of specimens at hand (only three) is not sufficient to deter- 
mine the constancy of the characters that distinguish it from tylorhinus. 
The chief differences, as above stated, are the longer tail and narrower 
jugal. The jugal is always narrower in females than in males, and two 
of the three specimens are females. The raa,le (type specimen), while 
full grown, is not. old, and its jugal may be abnormally slender, though 
there is nothing about the skull to suggest this belief. In the light of 
the present material no course seems open but to recognize the animal 
as a distinct species. It may be remarked, however, that it is the 
poorest species described in the present paper. 

Respecting its local distribution Mr. Nelson states : " On the slopes 
of the Volcano of Toluca this species is not very numerous, but is found 


[no. 8. 

scattered in small uiiinbers continuously from the base of the mountain 
up to the vicinity of timber line, usually in open parts of the pine forest 
and in small grassy parks. It is more common in the valley of Toluca, 
where it inhabits fields and grassy meadows and is very destructive 
to crops," 

(PI. 11, fig. 4, and pi. 14, fig. 8.) 

Geoniys fnmosiin Merriam, Proc. Biol. Soc. Washington, vii, September 29, 1892, 
165- IfiG 

Type locality. — Colima City, Mexico. (Type in TJ. S. National 

Geographic (Ustribution. — Plain of Colima, Mexico. (Altitude 1,500 to 
2,000 feet.) ' 

General characters. — Size medium, about equalling Geomys hursarius 
(smaller than the other species of Platygeomys)', pelage rather soft, 
sparingly mixed with long Avhitish bristles, which are most abundant 
on the rump; tail and hind feet nearly naked; nasal pad not strongly 
developed; color very dark. 

Color. — Upper parts everywhere plumbeous slate or dark sooty- 
brown, faintly washed in places, particularly along the sides, with pale 
reddish-brown; color of upper j^arts fading in worn pelage to pale dull 
liver brown, usually in irregular patches; underparts scant haired, 
pale plumbeous, sometimes indistinctly wa.shed with pale brownish. A 
young specimen, about half grown (No. 341SG S ), is rich slate black 
above, conspicuously lined with whitish bristly hairs, which are most 
abundant on the rump, and more so on the sides than along the middle 
of the back. There is also a fiiint brownish tinge on the sides of tlie 
neck. The scant hairs of the belly are very i^ale plumbeous or even 
soiled whitish. 

Cranial characters. — Skulls of Platygeomys fumosus agree with those 
of the other members of the gymnurus group in the extreme breadth 
of the hinder part of the cranium, due to the expansion of the squamo- 
sals beyond the parieties of the brain case, and in the great lateral 
production of the angle of the mandible. P. fumosus departs from 
the gymnurus series markedly in the form of the zygomatic arches, 
which, when looked at from above, are rounded instead of sharply 
angular anteriorly, and have the sides nearly parallel or bowed out- 
ward, so that they are broadest across the middle instead of anteriorl}^ 
In gymnurus they are usually widely divergent anteriorly. P. fumosus 
differs further from the other members of thi^, gymnurus series m greater 
interorbital breadth of frontals; strongly wedge-shaped nasals; more 
elongated postpalatal pits (which reach the plane of front of last 
molars), and in having the anterior end of Jugal more deeply embedded 
between the terminal forks of the maxillary arm of the zygoma. 


The jugals are but slightly (sometimes not at all) expanded anteri- 
orly, in which respect the species agrees with P. planicejys, from tlie 
A^olcauo of Toluca. It differs from the latter greatly in the extent to 
which the Jngal enters into the formation of the zygomatic arch; the 
jugal being so far overlapped by the maxillary and squamosal roots of 
the arch that its free upper border is short — less than half the length of 
the basioccipital iu median line. It differs from planiceps further in 
broader rostrum, less spreading and more strongly decurved zygomata, 
and shorter and broader ascending arms of the premaxilla, which are 
bluntly rounded off opposite the middle of the maxillary root of the 

Measurements. — Average of seven males from type locality: Total 
length, 287.5; tail vertebrae, 82.2; hind foot, 42. Average of three 
females from type locality: Total length, 277; tail vertebrae, 75.3; hind 
foot, 39.C. 
I For cranial measurements see Table E, p. 213. 

Specimens examined. — Total number, eleven; all from Colima City, 
Colima, Mexico. 

General remarks. — Platygeomys fumosushelongfi, to the gymnurus series, 
3f which it is the smallest species yet described. It differs markedly 
from the other members of the series in having the zygomatic arches 
rounded and nearly parallel instead of sharj)ly angular and strongly 
diverging anteriorly; and differs further in having the sides and rum]) 
beset with whitish bristles that ])rotrude far beyond the fur. 

The original description of this species was faulty in several respects 
and is here corrected. The material collected by Mr. Nelson since the 
original description was published has thrown a flood of light not only 
on the affinities of this species but also on the whole group. It is now 
dearth at /Vwo.sns is not related in any way to hispidus, authentic skulls 
of which are now available for the first time. 

Mr. Nelson found this species limited in distribution. His notes state 
that it was rather numerous in damp saline flats overgrown with cocoa- 
nut palms, wild fig trees, mesquites, and acacias, in the valley of the 
Colima River near the city of Colima. In the vicinity of Armeria, at 
m altitude of about 200 feet, a few hills were seen but none of the 
inimals were caught. Thence up the course of the Armeria river, on 
the plain of Colima the hills became more and more numerous, especially 
between the altitudes of 800 and 2,500 feet. The animals seem to live 
m isolated and limited colonies, between which, in apparently equally 
favorable ground they occur singly and rarely. One colony of con- 
siderable size occupies an open grassy area in the limestone belt between 
Colima and the volcano ; others were seen along the sandy border of tlie 
Armeria river bottom in a growth of low bushes, and in some thick 
thoruy woods on a dry bench bordering the Colima river a few miles 
below the city. 



[no. 8, 

Genus ORTHOGEOMYS* nob. 
(PI. 19, figs. 1 and 2; text figs. 60-64; map 8\) 
Type Geomi/s scalops Thomas, from Teiiuaxtepec, Mexico. 

Dental eharactcr.s. — ITpper premolar with three or four enamel plates, 
the posterior when present restricted to inner fourth; tm' and m^ with 
two enamel plates each. Third upper molar with an elongated heel and 
deep outer sulcus; inner sulcus variable; both inner and outer enamel 
plates normally reaching posterior end of heel, the inner plate usually- 
covering the posterior half of the inner side of the tooth, leaving a broad 
cement band in front of it (fig. 34, ", «, and »). In 0. scalops the outer 
plate is often divided, presenting an anomalous condition in the family 
(fig. 62). Posterior curvature of m' and m- and anterior curvature of 
mi and m., strongly developed. Shaft of upper pm straight. 

Upper incisor unisulcate, the sulcus widely open and slightly on inner 
side, but sometimes reaching middle. 

Fifi. &0.—Orthof)eomys .icalops. Longitudiual vertioal median aoction of skull, mesetlimoid and rome 

in place. (For key see tig. 7.) 


Fig. r,i.—Oitho<ienm>is xcalops. Mesetlimoid and vomer removed, showing endoturbinals. 
(For key see fig. 10.) 

* Orthogeom)i«, from ofjfioc, straight, -\- Geomi/s, in reference to the unusual shap 
of the skull. 

tThe posterior plate is present in both upper premolars of the type and only know 
specimen of 0. latifrons, but is altogether absent, or present as a very narrow stri 
on one side only, in 0. scalops an<l O. nelsoni. 


Skull as a whole miicli elongated; froutal extraordinarily broad and 
dat, much broader than muzzle, with sides nearly i)arallel (not exca- 
vated or concave laterally between the orbits, fig. 
17^); orbital plates of frontal not meeting inferiorly 
behind cribriform, but broadly separated by orbi- 
tosphenoids, as in Pappogeomys and Thomomys. 
Zygomata narrow or only moderately spreading. 
Brain case subcylindric, as seen from above, in ¥\(i.Q2.-orthogeomys 
I'ontinuation of^ the general form of the froutal f^eaiopa. Last upper mo- 

, , 1 1 r, 1^^ ^ 1 i /'A 1 -j^ 1 lar. h, divided outer 

ind nnizzle. Angle or mandible short. Urbitosphe- ^,nau^el piate. 
loids rather large, articulating with the anterior 
:)art of the alisphenoids and sending a tongue upward, partly filling 
]he upper i)art of the sphenoidal fissure (fig. 60). Mesethmoid a half 
•rescent, as in Cratogeomys; endoturbiuals as a whole quadrangular, 
he anterior border essentially parallel to cribriform plate; first endo- 
urbinal only slightly expanded and rounded anteriorly, as in Geomys; 
hird endoturbinal larger and much broader than second — a unique 
;oudition in the family (fig. 61). The palatopterygoids are long and nar- 
ow, and of nearly equal breadth throughout; the basal third or less, is 
)alatine; the distal two-thirds or more, pterygoid. The foramen rotun- 
limi and foramen ovale are nearer together than usual, and sometimes 
nerge into a single large opening which communicates directly with 
:be alisphenoid canal. 

External characters. — Size large; pelage very coarse, hispid or setose; 
lasal pad present or absent. 

Cranial characters. — The chief cranial characters that distinguish 
h-thogeomys from the other genera having essentially the same enamel 
)attern of the molariform series (Heterogeomys and Macrogeomys)* are 
he great breadth of the frontal interorbitally, absence of interorbital 
constriction, absence of conspicuous postoibital prominences or ridges, 
arge size and extended relations of orbitosphenoids, peculiar form of 
■ndoturbiuals, and shape of the palatopterygoids. The great length 
md narrowness of the cranium as a whole is matched by Macrogeomys 
htlichocephalus^ but the nearly uniform breadth of the upper part of 
lie skull and the form of the zygomata and palatopterygoids are very 
lifl'ereut. Tlie posterior position of the lateral enamel plates of m^, 
)0th of which normally reach the end of the heel, is a distinctive 


^elage setose; muzzle short latifrons. 

^elage not setose; muzzle long: 

i Frontal inflated ou orbital margin anteriorly ; m^ normal — 

j Nasals broad posteriorly grandis. 

I Nasals narrow posteriorly nelsoni. 

I Frontal inflatioa slight or absent; m' with outer enamel plate divided.. scaZo^^s 

* It has been stated in the preceding footnote that the upper premolar of Ortho- 
'eomys normally has only three enamel plates, while in Heierofieomys and Macro- 
•eomys four are always present. Hence the enamel pattern can hardly be said to be 
he same. 


[NO. 8. 


(PI. 19, figs. 1 and 2, aucl text tigs. 60-62.) 

Geomysscalops Thomas, Auuals aucl Mag. Nat. Hist., Othsenes, XIII, May, 1894, 437-438. 

Type from Tehuantepec, Mexico. (Type in British Museum). 

Gcof/raphic distribution. — Extreme southern Mexico, in State of 
Oaxaca, and probal)]y adjacent part of Chiapas. 

Mr. Nelson states that on the pme-covered slopes of the Cerro kSan 
Felipe, a few miles north of the city of Oaxaca, he found the diggings 
of this gopher extending ui)ward from an altitude of about 7,000 feet 
to the summit (altitude about 10,500 feet), always in pine or oak timber 
or in the small openings that occur in the forest. 

General characters. — Size rather large; pelage hispid j naked nasal 
pad large (measuring 20 mm. in length in fresh specimen); tail naked; 
hind feet naked, except for a few scattered colorless hairs ; ear opening 
surrounded by a brpad, thickened rim. 

Color. — Type specimen in worn, faded i^elage: "Smoky-brown, tend- 
ing rather toward rufous (very near 'Front's brown' of Eidgway)."— 
Thomas. An adult specimen from Cerro San Felipe, Oaxaca, col- 
lected June 21, 1894, by E. W. Nelson, is in good pelage and is dark 
seal-brown (almost black in places) with an evident gloss. 

Cranial characters. — Skull of adult 9 very long and narrow; frontal 
very broad interorbitally, not constricted in front of postorbital pro- 
cesses; zygomata little spreading, flattened, elongated autero-poste- 
riorly, the outer sides ])ara]lel; occipital plane sloping forward; paroc- 
cipital flanges turned backward, but not reaching plane of occipital 
condyles; palatopterygoids narrow, of nearly uniform breadth through- 
out, the pterygoids forming distal two thirds, but not reaching base of 
notch (see pi. 19, fig. 2). Interiorly the ])remaxilla reaches far behind the 
incisive foramina. Contrasted with latifrons, which it greatly resem- 
bles, scalo2)s diflers in having the rostrum much longer, the nasals 
broader, more arched anteriorly, and longer, and the jugal broader 
anteriorly. The resemblances and difterences are such as to at once 
suggest sexual variation — the skull of 0. latifrons differing from that of 
scalops in the way that female skulls usually differ from males in the 
Geomyidw — smaller size, shorter rostrum, and narrower jugals. But, 
unfortunately for this hypothesis, the specimen of scalops is an adult 
female, as shown both by the collector's label and by the conspicuous 
teats on the dry skin. Furthermore, the grooving of the upper incisors 
is very different and the external characters are marked. 

Since the above was written I have received nine additional speci- 
mens of 0. scalo2)s from Mr. Nelson, all collected in the Cerro San Felipe, 
near the city of Oaxaca, during the last week of August and 1st of Sep- 
tember, 1894. Two of these are adult males. Their skulls differ from 
those of the female in slightly larger size; more spreading and some- 
what heavier zygomata, which divaricate anteriorly instead of being 
parallel; in a more decided tendency to inflation of the anterior part of 


the border of the frontal : the development of a long sagittal ridge, and 
of much larger jiaroccipital processes, which reach backward behind 
the plane of the condyles. 

]Male skulls of scalops from Cerro San Felipe, Oaxaca, differ from 
males of nelsoni from Totoutepec and Mount Zempoaltepec, Oaxaca 
in the following characters. Size smaller, muzzle mucii narrower, the 
narrowness especially marked in the ascending branches of the pre- 
maxilla 5 nasals decidedly broader posteriorly and less eveidy acum 
inate, spreading more abruptly in front of the middle ; zygomatic arches 
more slender and more divergent anteriorly; frontal intlation less 
pronounced; paroccij)ital processes much larger ami directed more 
strongly backward, exceeding the plane of the condyles ; occipital plane 
less Hattened, and marked by three ridges, a median ridge and two 
lateral; palatoptery golds shorter; groove of upper incisors narrower. 

Dental characters. — Molars as in the genus. Upper incisors with a 
single deep and rather broad furrow wholly on inner side: outer side 
strongly convex. In latifrons the groove is relatively shallow and 
median, or nearly so. The outer enamel plate of the last upper molar 
is usually divided, making four instead of three plates for this tooth, 
a condition not observed elsewhere in the family (tig. 62). 

Measurements. — Type specimen (measured by Thomas from dry skin): 
Head and body, 270; tail, 95; hind foot, 45.2 (without claw, 40). 

Average of two males from Cerro San Felipe, Oaxaca (measured in 
flesh): Total length, 369; tail vertebrae, 103.5; hind foot, 50.* 

Average of eight females from same place: Total length, 360; tail 
vertebrne, 109 ; hind foot, 50. 

Cranial measurements. — Type specimen (measured hj Thomas) : Basal 
length, 63; basilar length of Hensel, 56.7; greatest zygomatic breadth, 
40.8; nasals, length 20, greatest breadth, S; least breadth of muzzle 
above maxillo-premaxillary suture, 15; interorbital breadth, 14.2; 
between tips of postorbital j)rocesses, 10.2; postglenoid breadth, 26.7; 
greatest squamosal breadth, 39; basion to occipital crest, 18.4; between 
tips of paroccipital processes, 27.5; palate from gnathion, 47; diastema, 
24.5. Upper molar series on crowns, 12.6; breadth of m', 4; least 
height of muzzle on diastema, 12. 

For other cranial measurements see Table F, p. 214. 

specimens examined. — Total number 13: 10 from Cerro San Felipe, 
Oaxaca, Mexico; 3 from mountains 15 miles west of city of Oaxaca. 

General remarks. — Orthogeomys scalops seems to be more closely 
related to 0. grandis than to 0. nelsoni. 

(Text fig. (>3.) 
Geomii>s (jratuUsThomtiH, Auuals aud Magazine Nat. Hist., 6 ,ser., XII, October, 1893, 
pp. 270-271. 

Type locality. — Duexas Guatemala. (Type m British Museum). 

*A larger series of males would undoubtedly result in larger average measure- 
ments, as neither of our specimens are very old. 


Oeographic distribution. — "Cominou all over the liighlaud« [of Guate- 
mala!, and traces of their presence are to be met with almost every- 
where in the neighborhood of Dueiias." — Biologia Centrali- Americana, 
Mammalui, 1880, IGO. 

General characters. — Size very large; upper incisors deeply unisul- 
cate, the sulcus on inner side and widely open ; tail naked ; fore and hind 
feet "very thinly haired, the few scattered bristles whitish;" pelage 
coarse. The following quotation is from Mr. Thomas's description of 
the type specimen: 

Color. — "Smoky chocolate brown throughout, except on the muzzle, 
cheeks, and chin, where the hairs are white or pale whitish brown. 
A few white hairs scattered over the back." 

Cranial characters. — " Skull large and heavily built. Ascending 
processes of premaxillaries surpassing the nasals by about a quarter of 
an inch ; the space between them behind the nasals less than the breadth 
of one of them. Interorbital space broad, as broad as the muzzle, its 
edges anteriorly rounded and inflated in a manner quite unique. Zygo- 
mata not very widely expanded in proportion to the size of the skull. 

"Incisors pale yellow or whitish, in marked contrast to the deep 
orange found in the allied species. Their single groove deep and very 
widely open, so that its greatest width on the cutting edge amounts to 
2 mm.; in position the bottom of the groove is internal, the breadtb 
of the inner portion of the tooth being about 13 to 45 percent of the 
whole; owing, however, to the great breadth of the. groove itself, it 
considerably overlaps the median line, but the above percentage is 
taken strictly from the bottom of the groove. Molar teeth large."* 

Measurements of type specimen (from dry skin). — Head and body, 320; 
tail, 135; hind foot, with claw, 57 ; without claw, 50; longest foreclaw, 23. 

For cranial measureinents see Table F, (i^. 214). 

General remarks. — This animal, though long known from Guatemala, 
had been confounded with Idspiilus until recently separated by Mr. 
Thomas, who, struck by its larger size and some other external differ- 
ences, removed the skull from one of Mr. Salvin's original Duefias 
si)ecimens and discovered the remarkable cranial peculiarities above 



(Text lig. 63. ) 
Type from Mt. Zempoaltepec, Oaxaca, Mexico. (Altitude 8,000 feet.) No. 66751 
(? ad. U. S. Natioual Museum, Department of Agriculture Collection. Collected 
July 8, 1894, by E. W. Nelson and E. A. Goldman. Original No. 6376. 

Geographic distribution. — Mt. Zempoaltepec in the State of Oaxaca, 
Mexico, and the adjacent region, including Gomaltepec and Totontepec. 

General characters. — Size, largest of the known species of the family, 
slightly exceeding 0. grandis of Guatemala, which it closely resembles, 
differing chietly in the fronto-nasal region of the skull. Ears larger 
than in any other member of the family; naked nasal pad large; tail 
naked except at base. 

* Annals and Magazine Nat. Hist., XII, October, 1893, 270-271. 

JAN., 189.0 



Color. — liuiform dull dark-brown; hardly paler below. 

Cranial characters. — Skull large, 'ong, and heavy, resembling both 
scalops and gramUs, but differing from both in the shape of the nasal 
bones, wliich are very much narroa-er pos- 
teriorly. Mr, Oldfield Thomas has had 
the kindness to compare his type of 
grauflis with the type and other skulls 
of nelsoni sent him for the purpose, and 
has taken the trouble to give nie a sketch 
of the fronto-nasal region of grandis, 
with a number of detailed measurements 
which show the differences between the 
two forms. In addition to the striking 
narrowness of the nasals posteriorly, 
nelsoni differs from grandis further in 
the following points : the ascending arms 
of the premaxilla reach much further 
backward, cutting the plane of the orbit; 
the articular face of the maxillary root 
of the zygoma (on top of the skull) is 
much longer, measuring 11.5 instead of 
8.7mm. ; the frontal is both narrower and 
shorter between the nasal branches of 
the premaxilla; the muzzle is narrower, 
the frontal broader, and the frontal in- 
flations are more anterior and less ex- 
treme. The mandible differs, not only from grandis, but from all known 
members of the family in the absence of the capsular inflation over the 
root of the incisor, between the condyle and angular process. It is 
entirely wanting in the type, and only family apparent in the adult 
female from the same locality. It is larger, but still abnormally small, 
in an old male from near Totontepec (No. CG753). The skull of the latter 
specimen is the largest I have seen of the species and the jugal is 
broader anteriorly than in the specimens from Mount Zempoaltepec. 

Skulls of 0. nelsoni differ from those of O. scalops in larger size, much 
broader muzzle, heavier zygomata, longer nasals, which are much nar- 
rower posteriorly and truly cuneate in form; much broader ascending 
branches of premaxilla; broader and decidedly more inflated frontal; 
U-shaped, instead of V-shaped postglenoid notch; flatter occipital 
plane, with less backward extension of the paroccipital processes. 

Measurements. — Type specimen, an adult $ from Mount Zempoalte- 
pec: total length, 397; tail, lL'3; hind foot, 53. Another male, from 
near Totontepec, is even larger: total length, 435; tail, 140; hind foot, 
55. An adult female from INIount Zempoaltepec measures: total length, 
380; tail, 118; hind foot, 52. 

For cranial measurements see Table F, p. 214. 
7433— No. 8 12 

Fig. 63. — Orlhogeom>/s nelaoni cT type 
(natural size). From Mouut Zempoalte- 
pec, Oaxaca, Mexico. 

178 • NORTH AMERICAN FAUNA. [no. 8. 

Specimens examined. — Five, all from the State of Oaxaca, southern 
Mexico: Mount Zempoaltepec, 2; near Toton tepee, 2; Comaltepec, 1. 

General remarks. — In color the specimens of 0. nelsoni (lifter mate- 
rially from Mr. Thomas's description of grandis. They are in ^vorn 
l)elage, and are very dark-brown, but the muzzle and cheeks are not 
paler. In fresh pelage they would i)robably resemble 0. sealo2)s in 
being rich seal-brown, almost black. The feet are evidently more hairy 
than those of grandis^ and the ears are larger than in any other mcDi- 
ber of the family, measuring about 5 mm. in height in the dry skin. 

(PI. 11, figs. 5 and 6; text fig. 64.) 

T(/2)f/ro»i Guatemala. Exact locality unknown. No. . U. S. National Museum 

(No. 2 World's Fair exhibit of Gnateniala). 

General characters. — Size medium (rather small for the tropical 
American species); incisor groove median or nearly so; tail long and 
absolutely naked ; hind feet naked, except a few scattering hairs; fore- 
feet scant haired ; nasal pad small or absent ; pelage hispid, scant and 
unusually long, unlike any known species of the family. The indi- 
vidual hairs are bristles, very much coarser and longer than those of 
Geomys liispidns. There is no under fur. The belly is so sparsely 
haired that the bare skin shows through. 

Color. — Everywhere uniform dull sooty-brown. 

Cranial cliaracters — Unfortunately the skull of the type and only 
known specimen of this remarkable animal is defective, the entire 
occipital region and the audita! bulhe being absent. The anterior part 
of the skull is perfect, including all of the teeth and one of the zygo- 
matic arches. The upper surface of the cranium is remarkably smooth 
and free from lateral indentations or projections, and is of almost uni- 
form breadth. Seen from above, the muzzle, frontal, and brain case 
pass into one another without interruption or constriction, the frontal 
being a trifle wider than the muzzle and the cylindrical brain case a 
trifle broader than the frontal. There is only a faint attempt at a 
postorbital prominenc^e, and it is below the level of the top of the 
skull and is made up of ttie alisphenoid and squamosal. The muzzle 
is short. The zygomata are narrow and slender, without any enlarge- 
ment or expansion at any point; they are broader i^osteriorly than 
anteriorly, and the maxillary arm slopes strongly backward. The 
jugal is small and slender and the arch is incomi)lete without it. The 
I)alatopterygoids are broken off. The ascending branches of the pre- 
maxilla slightly surpass the plane of the orbits. Inferiorly the pre- 
maxilla slightly passes the ])osterior end of the incisive foramina. The 
nasals are small, short, and narrow, but slightly broader anteriorly 
than posteriorly, and without trace of inflation. The angles of the 
mandible are short and flat. Unfortunately the i)alatopterygoids and 
audital bulhe are broken off, along with the whole of the occipital 
region, hence additional important characters may exist that are not 
apparent in the single specimen at hand. 


Dental characters. — The single groove of the upper incisors is median, 
open, and rather shallow, and the face of the tooth slopes toward it from 
both sides. It thus differs widely from the deep and abrupt groove of 
G. scalops, which is wholly on the inner side. The face of the incisors is 
orange; in scalops it is pale yellowish or straw-color. The long axes of 
the crowns of the individual molars are not quite 
transverse, but slope slightly backward toward 
the median line. In most species they slope for- 
ward. The heel of the last upper molar is short, 
but is sharply circumscribed. In addition to the 
usual deep sulcus on the outer side, the inner ' 
side is abruptly narrowed (tigs. 34" and 64). The 

. , Fig. 64. — Orthogeomys lati- 

enamel plates are peculiar: Inner enamel plate /;oris(tyiie). downs of mo- 
covering considerably more than half of inner lariform teeth.- « upper; h 
side of tooth, its anterior end bent outward at ^'^^^' 
nearly a right angle; its posterior end curved towar<l the median line 
and reaching the hindermost part of the heel; outer enamel plate cover- 
ing about five-sixths of the outer side of the tooth, its anterior third 
bent outward at right angles, its posterior half sloping strongly back- 
ward to the end of the heel, forming nearly a right angle with the mid- 
dle part and thus making two sharp angles instead of one — a unique 
condition. The posterior interspace is very narrow and is on the 
median line of the tooth behind. The inner interspace is twice as broad 
as the i)osterior. 

Measurements (from dry skin, not overstuffed). — Total length, 320; 
head and body, 235; tail. 100; hind foot with claw, 44; hind foot with- 
out claw, 39. 

General remarTis. — Externally Orthogeomys latifrons may be distin- 
guished from all other known members of the Geonnjidw by the char- 
acter of the pelage, M'hich is setose, the individual hairs being long- 
bristles. In cranial characters it closely resembles 0. scalops, but dif- 
fers in the much shorter muzzle and nasals (which latter are not at all 
inflated anteriorly), and narrower jugal. The upper incisors are very 
uidike. In latifrons the face is orange, the -groove median, or nearly 
median, and relatively shallow, and both sides slope similarly into it. 
In scalops the face is pale j^ellowish or straw color, the groove wholly 
on the inner side and deep and abrupt, and the outer side is strongly 
(roundly) convex. 

Genus HETEROGEOMYS * uob. 

(PI. 4; pi. 14, tig. 12; pi. 15, tig. 2; pi. 17, tig. 1; pi. 18, fig. 3; pi. 19, tig. 5; text 

tigs. 6~) and 66; map 3^.) 

T'lpi (leovii/n hispidiis LeConte, from near .Talapa, Vkra Cruz, Mexico. 

Dental characters. — Upper premolar with four enamel plates, the pos- 
terior restricted to inner or lingual half. Upper aud lower premolars 

* Hetcrogeomys, from trepur, different, -f- Geomys. 


siibequai in length. First and second npper molars witli two enamel 
plates each, the posterior complete. Third npper molar a double prism ; 
crown much longer than broad; posterior loop or heel strongly devel- 
oped; outer sulcus deep; inner sulcus slight; inner enamel plate cover- 
ing half or more than half of inner side of tooth and falling short of 
hinder end of heel; outer enamel plate very long, covering the whole 
of the outer side of the tooth behind the anterior cement band, and 
curving inward posteriorly to the median line of the tooth. At the 
lateral sulcus the outer enamel band bends outward at right angles. 
Posterior curvature of m' and m- and anterior curvature of mi and m2 
slight. Shaft of upper pm straight or faintly convex forward. Upper 
incisor unisulcate, the sulcus wholly on inner side of median line and 
sometimes on inner third; deep and abrnj^t (fig. 20^). 

Cranial characters. — Skull as a whole high and narrow; frontal broad 
and fiat; its sides biconcave interorbitally; distance between orbits 
much greater than length of basioccipital on median line; temporal 
impressions anteriorly defining a marked frontal shield ( fig. 17') ; 
orbital i)late of frontal usually perforated by a foramen above apex of 
sphenoidal fissure; zygomatic arches variable, outer sides nearly 
parallel, antero-exterual angle sharp and moderately expanded; infe- 
rior surface of palatopterygoids cuneate-lingulate, long and slender, 
the palatal arms much elongated, the pterygoid part small and ter- 
minal; postpalatal pits deep; nasals nnich arched anteriorly to support 
the large nasal callosity; occipital i^lane but little more than twice as 
broad as high, very flat, sloping strongly forward from below upward, 
squamosal part very high above mastoid bullae; orbitosphenoids shield- 
shaped, rather narrow and long, not articulating with alisphenoids ; * 
upper part of optic foramen disappearing in advanced life (pi. 17, fig. 1) ; 
endoturbinals peculiar, the first greatly expanded, its anterior face 
vertical or slightly emarginate (pi. 19, fig. 5). Mesethmoid rather 
small and strongly convex anteriorly (pi. 18, fig. 3). Sijuamosal expan- 
sion slight; fronto-maxillary suture reaching orbit in front of lachry- 
mal (instead of behind, as usual). Mandible short and compact; angu- 
lar processes short. 


Zygomata broadly spreading, divergent anteriorly ; nasals short torridiis. 

Zygomata not broadly spreading and not divergent anteriorly ; nasals rather 

Ion"' hispidits. 

* In immature skulls of S^fitero(7eomi/s the orbitosphenoid seems to articulate ante- 
riorly Avith the maxilla as well as the frontal, but careful examination shovrs it to be 
separated by the narrow descending arm of the frontal. In rare cases, irregular 
absorption of the exceedingly thin plate may permit the orbitosphenoid to reach 
the maxilla, 


(PI. 4; textlig-. 65; pi. 13, lig. 20 ; i>l. U, tig. 12; pi. 15. fig. 4.' 
Geomys hispidus LeConte, Proc. Acad. Nat. Sci., Pliila.,v, S eptember. 1852, 158. 

Type locality. — N"ear Jalapa, Vera Cruz,* Mexico. (Type in Acad. Nat. 
Sciences, Pliila.) 

Geographic distribution. — The 'Tierra Templada,' or middle belt, 
along the basal slope of the table-laud, in the State of Vera Cruz, 
Mexico, between the altitudes of 4,000 and 4,500 feet. Mr. Nelson found 
the species common about Jalapa and Jico, aud in less abundance from 
near the city of Orizaba north to Huatusco. The U. S. National 
Museum contains a specimen from Necostla (near Orizaba). 

General characters. — Size large; upi)er incisors deeply unisulcate, the 
sulcus wholly on inner side; tail naked; a large naked ])ad on end of 
nose; forefeet with claws shorter than hind; pelage harsh and stift', 
unlike any other species known to occur in Mexico except torridus. 

Color. — Upper parts everywhere uniform dark seal-brown; i hardly 
paler below. 

Cranial characters. — Skull as a whole high and narrow; frontal 
very broad and flat, depressed and biconcave interorbitally, concave 
both longitudinally and transversely; distance between orbits much 
greater than length of basioccipital on median liui^; temporal im^jres- 
sions forming elevated semicircular ridges sei)arated in both sexes by a 
distinct interval, and extending from postorbital prominences to outer 
angles of interparietal, anteriorly defining a marked frontal shiehl, and 
posteriorly inclosing a broad interparietal; zygomatic arches narrow, 
the maxillary arms sloping strongly backward, outer sides nearly 
parallel (sometimes broadest across the middle instead of anteriorly), 
antero-external angle sharp and moderately expanded, but not in the 
usual way; angle not produced downward; expansion oval in shape 
and encroaching on orbital fossa, which is correspondingly narrowed 
at this point; inferior surface of i:»alatine bones greatly elongated i^os- 
teriorly, forming, on either side of the postpalatal notch, narrow Ungu- 
late extensions which are terminated by short and narrow pterygoids; 
postpalatal pits deep; ascending branches of premaxilla broad and 
bluntly rounded posteriorly; premaxilla extending far enough posteri- 
orly to inclose incisive foramina; nasals inflated anteriorly and then 
contracted at nares; anterior nares larger than in the other groups; 
occipital plane a little more than twice as broad as high, very flat (free 

" The type specimen was collected by Mr. Pease in 1847 on the road followed by 
Scott's army "between Vera Cruz and the City of Mexico," which road passes through 
Jalapa. Mr. Nelson found the species abundant about Jalapa,, which is in the 
'Tierra Templada,' about halfway down the slope from the table-land to the coastal 
plain. He ascertained further that the species does not occur on the table-land, 
which is inhabited by other genera. 

tThis color maybe otherwise described as very dark plumbeous, faintly tinged 
with purple. 



[no. 8. 

from the projections and irregularities coinnioii to other forms), sloping 
strongly forward from below upward; brain case larger, more clearly 
defined, and higher above posterior root of zygoma than in any other 
group; squamosal expansion minimum, neither extending out far later- 
ally nor iucreasing length of glenoid fossa anteriorly — the usual shelf 
like projection into the orbito-temporal fossa from the posterior root of 
the zygoma being nearly obsolete; fronto-maxillary suture reaching 
orbit in front of lachrymal (instead of behind it as usual). Tliis arrange- 
ment broadens the frontal anteriorly, shortening and apparently weak- 
ening the attachment of the maxillary root of the zygoma. ^landible 
short and compact, little spreading posteriorly; angular j)rocess short; 
prominence over root of incisor low and flattened posteriorly; condylar 
process long and only slightly sloping inward. 



Fig. 65.—Heterogeomyshispi(his. Jico, Vera Cruz, Mexico. (Nat. size.) 

Fig. 66. — Heteroacomya torridus. Motzorongo, Vera Cruz, Mexico. (Nat. size.) 

Dental characters. — Front face of incisors perfectly flat, not rounded 
off on edges as in Gcomt/s, PlatygeomyN, and Zj/(/o(jeomi/s. Upper 
incisors deeply unisulcate, the groove narrow and wholly on inner 
side. Lower incisors without bevel or groove on outer face. Molars 
larger, heavier, and less flattened antero-posteriorly than in Geomys 
or Zygogeomys; crown of last upper molar elongated posteriorly and 
abruptly narrowed behind lateral sulcus, tlie crown. of posterior prism 
longer than anterior, to which it forms a distinct heel. Isthmus con- 
necting anterior and posterior lobes of uj)per premolar decidedly on 
inner side of tooth. 

Measurements (taken in flesh). — Average of two males from near type 
locality (Jico, 7 miles south of Jalapa, Vera Oruz) : Total length, 345; 



tail vertebme, 92.5; bind foot, 53. Average of three females from same 
place: Total lengtli, 310.0; tail vertebrti', 85.3; hind foot, 47.3.* 

For cranial measurements see Table F, p. 1*15. 

Specimens eiamined. — Total number 9, from the following localities 
in the State of Vera Cruz, Mexico: Jico, 0; Huatusco, 1; Necostla, 1; 
locality unknown, 1. 

General remarks. — Through the courtesy of Mr. Witmer Stone and 
other officers of the Academy of ISTatural Sciences of Philadelphia, the 
type specimen of Geomys hispidus has been sent me for examination. 
In size, character of j)elage, and all other respects except color, it 
agrees almost exa(;tly with Mr. Nelson's specimens. The color, Avhich 
LeConte described as "reddish-brown" and Baird as "red dish- brown or 
dull chestnut," was probably the result of museum exposure, the skin 
being mounted and exposed to the light. It was collected by Mr. Pease 
in 1817, during tlie march of Scott's army from VeraCruz to the City of 
Mexico, and consequently had been in the collection five years before 
it was described by LeConte. The fading has continued, the specimen 
now being much paler than when seen by Baird in 1855. 

In view of the large number of species of Pocket G-ophers now known 
to inhabit southern Mexico, it is exceedingly gratifying to be able to 
settle the status of his2)uliis by actual comparison of the type sijecimeu 
with the series collected by Mr. Nelson at or very near the original type 
locality. The skull of the type specimen has never been removed, and 
the cranial characters of the species have remained unrecorded until 
the present time. The series of skulls obtained by Mr. Nelson there- 
fore were examined with unusual interest and the result was a complete 
surprise. They show not only that the animal is a strongly marked 
species, but that it is generically distinct from Geomys, as already 
pointed out. 

The naked nasal pad is more largely developed in this species than 
in any of the others, and its large size is clearly correlated with the 
inflated nasal bones. For this reason it shows to unusual advantage 
in the type specimen, which is mounted with the skull inside, the arched 
nasals keeping it stretched in its natural relations. In this specimen 
it measures 12.5 mm. in length by 10 in breadth. 

Mr. Nelson states that H. hispidus is confined to the district suitable to 
the cultivation of coffee and sugar cane and is said to be very injurions 
to cane i^lantations. 

(PI. 15, fig. 2; pi. 17, fig. 1; pi. 18, fig. 3; pi. 19, fig. 5; text fig., G6.) 
Type from Chichicaxtle, Vera Cruz. No. 63629 9 ad., U. S. Natioual Museum, 
Department of Agriculture collection. Collected February 15, 1894, by E. W. 
Nelson. (Original number, 5850.) 

Geographic distribution. — Lowlands of Vera Cruz, from Chichicaxtle 

*The measurements of the feet of the mounted type specimen as taken by me now, 
nearly half a century after its capture, are : T'orefoot from basal pad to tip of longest 
claw, 42.5; hind foot from heel to tip of longest claw, 45.5. 


and Motzoroiigo to Catemaco, aud tlieuce into Guatemala; penetrating 
the interior to lieyes, Oaxaca, and (xLiatemala City, Guatemala. 

Mr. Nelson tir^t observed this species on the way from Mirador to 
the coast, from an altitude of about 1,500 feet near Santa Maria, down 
to the border of the sand hills along the coast at Antigua, The next 
l)oint where it was noted was on the route from the city of Cordoba to 
the hacienda of Motzorongo. At an altitude of 800 feet at this latter 
place it was again found in abundance. The easternmost locality at 
which it was obtained, by Mr. Nelson is Catemaco, in the district of 
Tuxtlas. He afterwards secured it at Reyes, in northern Oaxaca, at an 
altitude of 6,700 feet. The range of the species is strictly tropical. 

General characters. — Similar to H. hispidus. Size large; tail naked; 
naked nasal pad large; hind feet nearly naked; fore feet scant haired. 

Color. — Everywhere dark seal-brown, only slightly paler below; in 
worn pelage chocolate brown. 

Cranial characters. — Skull large, heavy and rather broad, resembling 
that of H. hisjjidus^ from which it differs in the following particulars: 
Pituitary fossa deeper aud (usually?) perforate; zygomata much more 
squarely spreading anteriorly (the maxillary arm standing out at more 
nearly a I'ight angle instead of sloping strongly backward); temporal 
impressions uniting iwsteriorly in old of both sexes, but not rising in 
a sagittal crest; audital bullii3 smaller, narrower anteriorly, and not 
sending u}) a point or ridge toward hamular process of pterygoid; ascend- 
ing arms of premaxilla averaging broader and shorter posteriorly. The 
skull of the male differs from that of the female in larger size and greater 
angularity. The zygomata reach out much further sideways, are much 
broader anteriorly than across the middle, and the outer angle stands out 
prominently (in the female it turns downward). The jugal is consid- 
erably larger and broader anteriorly in the male. 

Measurements (taken in tiesh). — Type specimen ( 9 ad. from Chichi- 
caxtle): Total length, 323; tail vertebroe, 88; hind foot, 52. 

Average of four adult males from Motzorongo: Total length, 348; 
tail vertebrti?, 9(3.5; hind foot, 49.2. 

Average often adult females from Motzorongo: Total length, 317; 
tail vertebrfB, 81.5 ; hind foot, 45.5. The 9 from Eeyes, Oaxaca, is 
decidedly larger, measuring: total length, 332; tail, 98; hind foot, 49,5. 

The mounted specimen in the World's Fair exhibit from Guatemala, 
which is considerably overstuffed, now measures: Total length, 380; 
tail vertebrae, 85; hind foot, 46. It is a female. 

For cranial measurements see Table F, p. 215. 

/Specimens examined. — Total number 27: 2 from Guatemala; 1 from 
Reyes, Oaxaca, and 24 from the following localities in Vera Cruz, Mex- 
ico: Chichicaxtle (type locality), 1; Motzorongo, 22; Catemaco, 1. 

General remarks. — Heterogeomys torridus differs but little externally 
from true his^ndns. Even in color the type specimen, which is in worn 
pelage, except on the head, is only a shade paler than si)ecimens of his- 


pidus in worn pelage. The differences in cranial characters, however, 
are marked and constant. Still it is quite possible that mtergrades 
maybe found in the exceedingly narrow belt separating the two forms. 
It should be observed that the type specimen has a hind foot 4 mm. 
longer than the largest female from Motzorongo, and that the skull, 
also, is larger. The type is a very old individual. 

Two specimens of a Heterogeojnys from (xuatemala, belonging to the 
U. S. ^national Museum collection, are here referred to the present 
species. One of these, a young adult (No. AV~A) "^^s collected many 
years ago near Guatemala City by Dr. Van Patten; the other was 
recently presented to the Museum by the Guatemala Commissioners to 
the World's Fair. The exact locality where it was obtained is unknown. 
It is an old female, and the temporal impressions meet over the middle 
part of the sagittal suture (which is obliterated, as in all adults of the 
species). The specimen obtained by Dr. Van Patten (probably also a 
female) is younger, and the temporal impressions are still distant. The 
two Guatemala skulls differ from those from Vera Cruz in having the 
postorbital prominence obsolete or nearly so. 

Mr. Nelson states that in Vera Cruz this species is one of the most 
injurious of the genus to the agriculturist. At Catemaco he found it 
in small numbers among the dry hills and plains on the western border 
of the lake, but in the forest on the eastern shore it swarms in countless 
numbers. At one point the ground was fairly honeycombed with their 
tunnels, so that he sank to the knee at nearly every step. 

Hefergeomys torrid ks becomes sexually mature at a remarkably early 
age. Several of the young females were mothers, and one in particular, 
though hardly half grown, has long ]^endant teats that have evidently 
been nursed. This specimen (Xo. 03040) is still m the woolly pelage of 
the very youiig, and its skull, barely half the size of the adult, has not 
yet attained tlie mature form. The animal could hardly be more than 
three months old. Its measurements m the tiesli are : Total length, 259 ; 
tail vertebra^, 71; hind foot, 43. 

Genus MACROGEOMYS * uob. 

(PI 5; pi. 11, figs. 2 aud 3; pi. 13, figs. 18, 19, 22, and 23; pi. 14, figs. 3 and 10.) 
Type Geomiifs heierodus Peters, from Costa Rica. 

Dental characters. — Upper premolar with four enamel plates, the pos- 
terior restricted to inner third; m' and m^ with two enamel plates 
each. Last upper molar witli an elongated heel and deep outer sulcns; 
inner emargmation variable (slight in heierodus; deep in doUchoceph- 
alus); inner enamel plate covering half to two-thirds of inner side of 
the tooth, its posterior end nearly reaching hinder end of heel. Outer 
enamel plate variable, the posterior limb double the length of the ante- 
rior. In ili. heterodus it covers half; in dolichoceiihalus aud eostari- 

' Maciogeomys, from /uaKpw, large, great, -f Geomys, in reference to the large size 
of the animals. 


censis^ three-fourtlis of the outer side of thetootli. The posterior loop 
or heel is greatly developed, sittaiuiiig the maximuiu size known in the 
family (about half or more than half the length of the tooth and uar 
row, the constriction about half the breadth of tlie anterior prism). 

Posterior curvature of m^ and ni'' and anterior curvature of mj and in? 
strongly developed. Shaft of both upper and lower premolar strongly 
convex forward and very large and heavy. 

Upper incisor unisulcate, the sulcus wholly on iyner third of face, 
narrow and deep; face of tooth flat on both sides of sulcus (fig. 20', 
and pi. 15, tig. 8). 

Cranial characters. — Frontal broad, flat, depressed or concave along 
the median line, deeply excavated laterally between the orbits, the 
notch immediately succeeded by a strongly developed postorbital proc- 
ess (much larger than in any other member of the family, fig. 17'). 
Palatopterygoids broad, short, and truncated posteriorly, the horizontal 
part composed almost wholly of the palatal, the pterygoid simply cap- 
ping the end and abruptly upturned at right angles (fig. 11^). Nasals 
moderately convex, slightly or not inflated. Brain case rising high 
above posterior root of zygoma. Unfortunately there are no skulls of 
Macrogeomys in the Department collection: hence I have been unable 
to make sections to ex])ose the mesethmoid and turbiuals. 

The lambdoid crest is straight or slightly convex posteriorly (not 
sinuous as in riatygeomys) and the occipital jdane Is flat and slopes 
strongly forward, as in Ileterogeomys. 

External characters. — Size large; naked nasal pad well developed; 
tail naked; pelage soft, almost silky, and with a tendency to become 
wavy; color pattern unique-, bicolor : muzzle and sides of rump abruptly 
whitish ; rest of upper parts dark chocolate or sepia in marked con- 
trast. (The color pattern of the adult M. costaricensis and cherriei is 

General remarlcs. — Macrogeomys requires comparison with only two 
genera, Hcterogeomys and Orthogcomys, from both of which it may be 
distinguished at a glance, whether viewed from above or below. The 
most striking points of diflerence are the remarkably short and broad 
palatopterygoids and the strongly developed postorbital processes. 


AudUal hidla normal, outer side not flattened. 

Skull short and broad ; zy "omata divergent anteriorly heterodus. 

Skull long and narrow ; zygomata parallel dolhlioeephalus. 

AudUal huUa pccurmr, the outer side flattened and disk-shaped. 

Jugal normal, entering largely into zygoma cherriei. 

Jugal small, the zygoma complete above without it costaricensis 

(PL 11, fig. 2; pl.U, fig. 3). 
Geomiis heterodus Peters, Monatsber. K. Preuss. Akad. Wiss., Cerlm (1864), 1865, 177. 
(Tran.slation of original description appended to present article, p. 189.) 

Type locality. — Costa Rica. Exact locality unknown. 


GetK/raphic distribution. — The Ira/Ai range and perhaps other parts of 
Costa Eica. 

General eharacters. — Si/e large; face of upper incisors deeply unisul- 
cate, tlie sulcus narrow and wholly on inner side of median hue; enamel 
face of incisors orange; naked nasal pad large; tail absolutely naked; 
hind feet naked, with a few stift' hairs about the toes; fore feet nearly 
naked (shorter than hind); pelage moderately coarse, but not hispid as 
[in G. hispidus; no external ears. Coloration peculiar, the muzzle and 
^ides, including sides of rump, being conspicuously paler than rest of 
ipper parts. 

Color. — Upper parts uniform sepia or hair brown; muzzle, under 
i)arts, and sides all round abruptly much paler, the pale color (a soiled 
i-ray) reaching higher on the sides of rump than elsewhere and includ- 
ing base of tail. 

Cranial characters. — Skull large, heavy, and rather short; zygomata 
jroadly spreading, their sides divergent anteriorly, maxillary arms 
;loi)ing backward less strongly than in (lolichocephalus; antero external 
ingle well marked, moderately expanded ; jugal large and broad, its 
ipper surface not covered by squamosal and maxillary arms; frontal 
jroad and flat, concave along tlie median line between the orbits and 
leeply notched on the sides immediately in front of the large post- 
)rl)ital processes, which latter are capped by the apex of the alisphenoid 
md overlapped posteriorly by the anterior edge of the squamosal. 
S^asalsbroadly wedge-shaped and not inflated. The ascending branches 
»f the premaxilla slightly exceed the plane of the orbits. Inferiorly the 
)remaxilla reaches but does not inclose the posterior end of the incisive 
"or9jmina. The zygomatic breadth is considerably greater than the 
■greatest squamosal or mastoid breadth. The occipital plane is flat 
except a vertical median ridge) and slopes moderately forward ; the 
ambdoid crest is straight, slightly incurved near median line. The 
lalatopterygoids are broadly U-shaped and shortly truncate posteri- 
orly, the pterygoids abruptly upturned at right angles to the palatals. 
The basioccipital has the sides parallel for the anterior half and is 
broadly wedge-shaped posteriorly. Audital and mastoid bullii^. normal. 
The enamel face of the upper incisors is flat, with the sulcus deep, rather 
narrow, and wholly on inner side. Traces of the fine inner sulcus may 
ilso be seen in the only specimen at hand. The heel of the last upper 
molar is narrow, much elongated, and slopes strongly outward. 

Macrof/eomys heterodus differs from 3f. dolichoceplialus, the only known 
sjiecies Avitli which it requires comparison, in the very different form 
of the skull as a whole, it being nuich shorter and broader, and in the 
following details: Jugal broadest anteriorly and not covered by squa- 
mosal and maxillary arms of zygoma; zygomata divergent anteriorly 
(mstead of ])arallel); nasals shorter and not inflated; orbital borders 
of frontal not inflated anteriorly; muzzle and diastema much shorter; 
palatopterygoids less broad at base; occipital plane broader and lower; 


mastoid biillai iiiiiTower vertically. Mandible iiuich slioiter. Heel of 
last upper molar longer and narrower, the outer eaamel plate reach- 
ing little moie than halfway from sulcus to end of lieel; in fJolicho 
cephalus it reaches all the way. 

Measurements. — Peters recorded no measurements for his type speci- 
men, but Dr. Matschie lias kindly measured it for me and finds the total 
leugtli 325 mm. He states that the tail is defective. The specimen in 
the U. S. ^National Museum, from the Irazu Mountains, wliich is the 
subject of the foregoing description (a well made dry skin), affords the 
following measurements: Total length, 325; head and body, 280; tail, 
65; hind foot with claw, 45; hind foot without claw, 41. 

For cranial measurements see Table F, p. 215. 

General remarks. — The only species kn(>wn to me with which hetero- 
dus needs comparison is dolichocrplialits, which agrees with it in the 
abrupt paleness of the nnizzle and sides of the rump. But heterodm 
differs from dolicliocephnlus m liaving the entire under parts and lower 
sides of the same pale color as the muzzle and sides of the rump. It 
differs further (in the specimens at hand) m the tint of the upper 
parts, which is sepia or hair brown instead of chocolate brown, and in 
the cranial characters above pointed out. 

Unfortunately, Peters's description ot his G. lieterodus from Costa Rica 
is brief and unaccompanied by measurements, cranial characters, or 
exact locality (see next page). That his animal is the same as hispidm 
of LeConte (from Vera Cruz), as assumed by Coues and Alston, is 
exceedingly improbable on geographic grounds (in view of the remark- 
ably restricted ranges of all the tropical American species row known) 
and impossible in view of the wide difference in coloration. Peters 
described heterodits as bicolnr, the upper i)arts "dark brown,"' the muz- 
zle, rump, and underi^arts "brownish gray or white.'' Hispidus is eon- 
color and uniformly dark. Fortunately the type of Peters's heterodus is 
extant. It is still in the Berlin Museum, and Dr. Paul Matschie of that 
museum has had the kindness to send me additional notes, accompanied 
by full cranial measurements, which suffice to place its identity beyond 

Through the courtesy of Mr. F. W. True, Curator of Mammals in the 
United States National Museum, I have been able to examine several 
specimens of the G corny Ida- from Costa Rica and Guatemala. Among 
those from Costa Rica is one which agrees in every way with Peters's 
original description of heterodus, and also with the additional particu- 
lars concerning Peters's type specimen kindly furnished me by Dr. 
Matschie. This specimen was recently presented to the museum by 
the Costa Rica Government through its commissioners to the World's 
Columbian Fxposition at Chicago in 1893. It consists of a well-pre- 
pared skill, from which Mr. True has kindly had the skull extracted. 
It is the only specimen of heterodus I have seen, and is the subject ot 
the foregoing description. Mr. George K. Cherrie, of the Costa Rica 


National Museum, in res{)onse to a letter of iuqiiiiy, coutributes the 
f'ollowiDjj important statement respecting this specimen: "It is No. 313 
of tbe collection of the ' Museo Nacional,' an adult male; was collected 
October 15, 181)0, near Rancho Iledondo, a point on the Irazu range 
between the volcanoes Irazu and Barba, at an altitude of about 1,400 
meters. The specimen was purchased from a 'peon' and mounted by 
myself. October is the last month of the rainy season, and the month 
in which it rains hardest. I might also add that the species is abundant 
in the locality given above." 

Peters's original description of hcterodus is as follows: "Our museum 
has received through Dr. Hoffmann and Dr. v. Frantzius the skin with 
the perfect skull of a new species of Geomi/s from Costa Rica, whereby 
the geographical distribution of this genus in Central America is estab- 
lished. This species agrees best with G. mexicanus Licht. in size, pro- 
portion of tlie limbs, nakedness of the tail, and the nature of its hairy 
covering, which latter, however, appears to be somewhat shorter and 
stifter. The color is dark brown except on the belly, rump, and muzzle, 
which are brownish gray or white. It is, however, readdy distinguished 
by the position of the deep longitudinal groove of the upper incisors, 
which does not run along the middle but between the inner and middle 
thirds of the teeth, for which reason I propose to name the species Geoniys 
heterodusy (Monatsber. K. Preuss. Akad. Wiss., Berlin, 1864, 177.) 

Dr. Paul Matschie has kindly sent me the following cranial meas- 
urements of Peters's type specimen of heterodiis, which is in the Berlin 
Museum (No. 2864) : 

Greatest basal length (condyle to front of premaxilla), 61; basal 
length (basion to gnathion), 58 ; basilar length of Hensel (basion to alveo- 
lous of incisor), 51.2; greatest breadth across squamosals, 38; least 
breadth between postglenoid notches, 27.5; least interorbital breadth, 
11; breadth across postorbital processes, 15.25; height of cranium above 
palate, 24; height above basion, 17; length of upper molar series on 
alveoli, 14; length of diastema, 22.5; length of single mandible (condyle 
to front of jaw between incisors), 44; breadth across angular processes, 
40; distance from condyle to end of angular process, 13; breadth of 
muzzle just in front of zygoma, 15. 


(PI. 5; pi. 10, fig. 7; pi. 13, fig. 19.) 

Type from. San Jose, Costa Rica. No. jH^tAV J ad. Collected Janiiary, 1866, by 
Jo86 C. Zeledon. 

Geographic distributum. — Vicinity of San Jose, Costa Rica. Range 

General characters. — Size large. Animal similar to .1/. hcterodus; face 
of upper incisors deeply unisulcate, the sulcus narrow and wholly on 
inner side of median line (pi. 15, fig. 8) ; enamel face of incisors orange; 


naked nasal pad large;* tail absolutely naked; bind feet naked, with a 
few stiff hairs about the toes; fore feet nearly naked (shorter than hind); 
pelage moderately coarse, but not hispid ;is in Jleterof/comys hi.spuhis; 
no external ears. Coloration ])eculiar, the muzzle and sides of rump 
conspicuously paler than rest of ui)per parts, as in heterodus. 

Color. — Upper parts dull chocolate browu, except muzzle and lower 
part of rump, which are buffy iu couspicuous contrast, but without liue 
of demarkation. (The buffy of the rump surrounds the base of the tail 
and reaches further anteriorly on the sides than along the middle of the 
back.) Under parts simihir to back but paler, without line of demar- 
kation ; wrists and ankles pale. No dark patch around ears. 

Cranial characters. — The skull of Macrof/eomys dolichocephalus, in 
addition to the generic characters which associate it with. M. heterodm, 
is remarkable for its length and narrowness, the zygomatic breadth in 
an old male (the type specimen) beiug only 58 percent of the total 
length (from condyle to point of premaxilla), and tlie greatest squamo- 
sal or mastoid breadth only 57 percent. The opposite extreme is found 
in the genus Platygeomys, in wh4ch the corresponding ratios in P. gym- 
mtrus are 71 and 75. 

The zygomata are not ouly very narrow, but present the appearance 
of having been drawn out while in a plastic condition. The maxillary 
arms slope strongly backward and are broadly rounded off' without 
tra(.'e of angle or of angular expansion at the usual place, though 
there is a shght expansion about the middle of the outer side of the 
ai-ih, encroaching on the orbitotemporal fossa, which it constricts in 
the middle opposite the large postorbital processes — a step toward the 
differentiafion ot these two fossie from one another. The jugal is 
broad, short anteriorly, narrower at both ends than iu the middle, 
and is overlapped by the maxillary and squamosal arms of the 
zygoma, which nearly or quite meet above it. The frontal is grooved 
medially between the orbits and is somewhat inflated along the 
margin of the orbits behind the lachrymal bones, in this respect 
resembling grandis of Thomas, though the inflation is much less 
extreme. The sides of the frontal are deeply notched immediately in 
front ot the large postorbital processes. The nasals are wedge-shaped 
as iu heterodus, but longer and slightly inflated anteriorly; they are 
broadest near junction of middle and anterior thirds (in the S only). 
The ascending branches of the preuiaxilla barely reach the plane of 
the orbits. Inferiorly the premaxilla reaches the posterior end of, but 
does not inclose, the incisive foramina, as in hcterodus. The zygomatic 
breadth is only a trifle greatei than the mastoid breadth. The 0(;<'i])ital 
plane is flat, high, and slopes strongly forward; the lambdoid crest is 
slightly convex posteriorly. The palatopterygoids are very broad and 

''In an alcoholic specimeu (No 1466 U. S. Nationul Museum) the nasal pad or cal- 
losity 18 broad and rather short, not reaching posteriorly behind plane of upper 



short. (Ill the male skull the pterygoids are broken off; m the female 
they are abruptly upturned, as in heterodns.] The basioccipital lias the 
sides parallel in the anterior half and is broadly wedge-shaped poste- 
riorly. The height of the cranium above the palate is unusually great, 
and the zygomata do not descend below a plane drawn midway of the 
height of the skull. The audital bulhe are normal and rather short, 
l)lump, and well rounded anteriorly. The brain case seen from above 
is subcylindric in shape, in which respect it resembles Ortliogeomys. 
The nasals end in front of the plane of the zygomatic arches, while the 
premaxillai reach the plane of the orbits, causing an unusual elongation 
of the median part of the frontal in order to articulate with the nasals. 
The mandible is long and narrow. The enamel face of the upper incisors 
is flat, the sulcus deep, narrow, and wholly on inner side (fig. 20'). 

A young female of M. doUcliocephalus (Xo. 30820) differs from the old 
male above described (36295) in the following particulars: The skull as 
a whole is very much smaller (see table of cranial measurements) ; nasals 
very much shorter, flatter, and broadest anteriorly (instead of at junc- 
tion of middle and anterior thirds) ; temporal impressions distant (inter- 
space 3 to 4 mm broad); brain case less cylindrical (owing in part to 
gTeater depth of constriction running obliquely upward from posterior 
root of zygoma to occiput, and in part to a slight bulging upward of the 
middle of the brain case) ; basiocciiiital narrower. The top of the skull 
in profile is not a straight line, tlie brain case presenting a slight con- 
vexity behind the orbits, while the interparietal and occipital crest fall 
below the plane of the upper surface as a whole. In both sexes the 
ciuterior part of the nasals is strongly decurved. 

M. (lolichocepha(u.s differs markedly from J/, heterodns, the only species 
rtitii which it requires comparison, in the general form of the cranium, 
.vhich is narrow and greatly elongated; in the narrow, drawn out 
'Tgomata, without trace of angular projection or expansion ; in the nar- 
•ower jugal, which is covered above by the anterior and posterior arms 
'f the, arch, Avhich meet ot nearly meet above it; in having the zygo- 
nata parallel (instead of divergent anteriorly); the nasals longer and 
iomewhat inflated anteriorly; the muzzle and diastema much longer; 
he palatopterygoids broader at base; the occipital plane higher and 
ess broad; the mastoid bull* much higher vertically; and the mandible 
'inch longer. 

Measurements (of type specimen, $ ad., from dry skin): Total length, 
ibout 380 (approximate, as the tail was not wired and is shrunken); 
lead and body, 310; tail, about 75 (approximate only); hind foot, 48; 
\ ithout claw, 45. 

Measurement of a young female from Costa Rica, preserved in alcohol 
^^' HiU ? yg. ad., U. S. National Museum, collected bv Jose C. Zeledon 
ind received in October,1884): Total length,310; tail, 74; hind foot, with 
law, 49; without claw, 43; forefoot, with claw, 45; without claw, 33. 

For cianial measurements see Table F, p. 215. 


General rpmarl-s. — Extern;illy Macrogeomys ilolirhocephalns resembles 
31. lirierodus in the peculiar paleness of the muzzle and sides of the 
rump (in strong' contrast to the color of the rest of the upper parts), but 
differs from heterodus in not havin.i;- the lower pait of the sides and belly, 
of the same pale tint. On the other hand, the pale color of the rump 
reaches a little further forward on the dorsal surface. There is a slight 
difference also iu the tint of the upper parts, the color being dull choco- 
late brown iu (loHchocephaJus, while it is sepia or hair brown in heterodus. 
The important cranial differences have been ]>ointed out. 

The alcoholic specimen already mentioned (No. 14GC6) is a female, and 
although not fully adult, has borne young, as shown by the large pen- 
dent ni])ples. The teats are: pectoral. y, inguinal | = |, as usual in the 
group. The pectoral pair are situated on the sides immediately behind 
the fore legs. The inguinal pairs are not on the belly at all, but on the 
mner side of the fA<V///s just below and outside of the belly. 

The great callosity at the hinder edge of the wrist is made up of two 
large tubercles resembling kernels of corn placed side by side and cov- 
ered by common integument. 


(PI. 11, fig. 3; pi. 13, fig. 23; pi. 14, fig. 10.) 

Type from Pacuare, Costa Rica. No. iMH j"'^'- U. S. National Museum. Collected 
in 1876 by Juan Cooper. (Original No. 96.) 

General characters. — Ui^per incisors with a single dee]) sulcus wholly 
on inner side; pelage in type specimen (immature) short aud silky, 
suggesting the fine crinkled pelage of Didelphi.s miirina; tail and hind 
feet naked; a conspicuous naked pad on end of nose. 

Color, — Upper parts uniform dark-brown, not paler on nose and 
rump; underparts abruptly whitish. The type and only known speci- 
men has a large symmetrical white spot on top of the head, occupying 
about three-fourths of the area bounded by the eyes and ears.* 

Cranial characters (of immature skull, pi. 11, fig. 3). — Similar iu a 
general way to an immature 9 skull of M. dolichocephalus (Xo. 36820), 
from which it differs in the foUowiug particulars: Nasals very much 
broader throughout, particularly posteriorly; space between posterior 
ends of ascending arms of premaxilla about twice as broad; zygomata 
standing out more squarely, nearly at right angles to axis of skull, 
with anterior angle abruptly rounded; jugal narrower; palatoptery- 
goids shorter and broader; basioccipital very much broader and wedge- 
shaped, its inferior surface not excavated by audital bullae ; audital 

*The white crown patch of costaricensis was at first believed to be abnormal, 
ailing in the same category with the irregular white blotches frequently fouud ou 
the throat and sometimes at the base of the tail, iu various species of pot ket 
gophers. But the fact that the spot is bilaterally symmetrical, and is repeated in 
the only specimen known of a closely allied species, cherriei, points to its perma- 
nence, at least as a mark of the young 


bulla peculiar, compressed, the outer side strongly flattened' more 
smoothly rounded, somewhat disk-shaped, and separated from the 
mastoid bulla interiorly by a distinct groove. The only other known 
species of the family having a similar audital bulla is Macrogeomys 
cherriei of Allen. Both are known from single specimens only, and 
both are too young to show all of the characters of the adult. Their 
specific distinctness will be apparent at a glance at the accompanying 
cut (fig. 67) showing the differences in the jugals. The palatoptery- 
golds also are different. The palatopterygoids of 71/. costaricensis are 
shown on pi. 14, fig. 10, but the figure is inaccurate; in the specimen 
they are sliorter and broader, more nearly as in fig. 3 of the same 
plate. The pterygoids of cherriei are broken, but the remaining base 
shows that they are considerably more slender. 

In M. costaricensis the jugal is much shorter than the basioccipital 
(measured from condyle) and is wholly inferior, the maxillary and 
squamosal roots of the zygoma meeting above it and on its inner side, 
so that when ^•iewed from the inner side it appears only as a narrow 
edge with the apex upward (fig. 67, *). In position and relations, 
therefore, it resembles Zygogeomys trichopus, though considerably 
broader than in that species. 

Fig. 67.— Zygomatic arches of Jilacrogcomyg costaricensis (3 and 4), and If. cherriei (1 and 2). 1 and 3 

outer side ; 2 and 4 inner side. 

Measurements. — Type specimen (probably not more than two-thirds 
grown) from dry skin: Total length, 330; tail (apparently stretched), 
100 from point assumed to be over first caudal vertebra, 80 from 
apparent base; hind foot, 37 (without claw, 33). 

For cranial measurements see Table F, i>. 215. 

General remarlcs. — This singular species, for the privilege of describ- 
ing which I am indebted to the courtesy of Mr. F. W. True, Curator 
of Mammals in the U. S. National Museum, is represented in the 
collection by an immature specimen only. At first it was supposed to 
be the young of M. (lolic/iocephahis, but comparison of its skull with 
that of dolichocephalus shows numerous points of specific difference, as 
above mentioned. While the peculiar texture of its pelage may be 
due in part to immaturity, this explanation fails when applied to the 
cranial characters which, as described above, are numerous and strik- 
ing and of such a nature that most of them would be accentuated by 
age. In external appearance the animal bears a striking resemblance 
to the young type of Macrogeomys cherriei. 
7433— No. 8 13 



(PI. 15, fig. 1.) 
Geomys cherriei Allen, Bull. Am. Mus. Nat. Hist., V, 337-338, Dec. 16, 1893. 

Type from Santa Clara, Costa Rica. No. G64 S im. Museo Nacional 
de Costa Rica. Collected in October, 1892, by George K. Clierrie. 

General characters. — Naked nasal pad large; tail and hind feet naked. 
Similar to Macrogeomys costaricciisis in size and coloration, including 
the white head patch, but differing in important cranial characters. 

Color (of type, jnv.). — Upper parts very dark plumbeous or sooty 
brown.; under parts abruptly paler, with distinct line of demarkation; 
top of head between eyes and ears pure white. 

Cranial characters [i^rom skull of type, but little more than half grown, 
pi. 15, fig. 1).— The skull of ili. cherriei agrees with Heterogeomys 
hispidus in general form, in the widely-seiiarated temporal imjiressious; 
the broad and fiat frontal, depressed between the orbits; the flat 
forward-sloping occipital plane; the form of the zygomata; the inflated 
nasals, and the short and compact under jaw, with short angular pro- 
cesses. But it is so young that one must be cautious in placing much 
stress on characters that vary with age. It differs from H. hispidus 
and agrees with 71/. costaricensis in the convexity of the anterior part 
of the roof of the brain case;* m the peculiarly flattened and smoothly 
rounded audital bulla?, which are separated from the mastoid bullae by 
a distinct inferior transverse groove; and in the h>ng heel of the last 
upper molar. It differs from costaricensis in the size, form, and rela- 
tions of the jugal (as shown in fig. 07), in narrower palatopterygoid 
lingular, and in a narrower gap behind the nasals (between posterior 
ends of ascending branches of prcmaxilla). -The jugal is large and 
long, and nearly half of its upper edge enters into the orbital fossa; it 
is not covered anteriorly by the maxillary arm of the zygoma, and its 
total length is greater than that of the basioccipital (measured from 
condyle). In M. costaricensis the jugal is much shorter than the basi- 
occipital (measured from condyle), and is completely covered by the 
maxillary and squamosal arms of the zygoma, which meet above it (fig. 
07). It differs further from costaricensis in the shape of the horizontal 
part of the zygomatic arch, which is not strongly convex upward, and 
lacks the constriction tending toward the separation of the orbital 
from the temporal fossa. The large orbitotemporal fosstii are broadest 
across the middle — ^just Avhere they are narrowest in costaricensis. 

Measurements. — Hind foot, with claws, 39 mm. (in dry skin). No 
measurements were recorded from the flesh, and the specimen is far 
from full grown. 

For cranial measurements see Table F, p. 215. 

General re»mr7c,s.— Through the courtesy of Dr. J. A. Allen, Curator 
of Mammals in the American Museum of Natural History of New 

* It 18 probable that the saddle-shaped frontal ot costaricensis and cherriei is the 
resxalt of immaturity, since a .young skull of G. trichopus (No. 50104) shows the same 
peculiarity, though m less degree. 


. 1 k, I have been able to examine the only specimen known of this 
sjKcies. It belongs to the Museo Nacional de Oosta-Kica, and was 
loiiiicd Dr. Allen by Mr. George K. Cherrie, who collected it at Santa 
Chira, Costa Eica, in October, 1892. It is a male, and, like the type of 
cosfaricensis, is immature. It resembles the latter in having a large 
pure-white patch on top of the head,* in the large size of the naked 
nasal pad or callosity, and in the nakedness of the tail and feet. The 
hind feet are absolutely naked; the forefeet are naked except for the 
presence of a few long hairs about the toes. The color of the upper 
parts is somewhat darker than in co.staricensis. The specimen is so 
young that some hesitancy is felt in its generic assignment. It may 
hen Ecterof/eomys instead of a 3Iacrogeomys, though this is exceedingly 

Genus ZYGOGEOMYS t nob. 
(PI. 6; pi. 13, fig. 24; pi. 14, fig. 1; pi. 15, fig. 10; pi. 17, fig. 2; pi. 18, fig. 2; pi. 19, fig. 4.) 

Type Zy(/ogeomys tncJiopus sp. no v., from Xahuatzin, Michoacan, 

Generic characters. — Upper premolar with four enamel plates, the pos- 
terior restricted to lingual third ; upper and lower premolars subequal in 
length; shaft of upper premolar slightly convex forward. 

First and second upper molars with two enamel plates each, the 
posterior failing on outer side. Third upper molar an incomplete dou- 
ble prism; crown nuich longer than broad; heel well developed, broad, 
narrowed on outer side only; sulcus on middle of outer side; absent 
ou inner side. Inner enamel plate covering two-thirds to three-fourths 
of inner side of tooth, straight, reaching end of heel posteriorly; outer 
enamel 2)lttte covering about half or a little less than half of outer side of 
tooth, its anterior half bent strongly outward. Interspaces broadly 
open, the posterior broadest, directed backward, and often forming a 
sort of everted lip (fig. 27^). 

Upper inclHors bisulcate; principal sulcus on inner side of median 
line; minor sulcus on inner convexity (see fig. 22^ and pi. 15, tig. 10). 

Cranial characters.^ — Cranium as a whole long and narrow, the zygo- 
mata not widely spreading, slender, antero external angle rounded and 
not expanded; zygomatic arch normally complete without jugal, the 

* The white crown patch of cherriei and costaricensis was at first believed to ba 
almoraial. lint the fact that the .spot is bilaterally symmetrical, and is repeated in 
the only specimen known o{ Macrogeomys cosfariceiisis, which is likewise young, sug- 
gests its possible permanence, at least as a mark of immaturity. 

'\ Zy(io(ieomiis, with reference to the unique cliaracter of the zygomata. 

! Owing to the extreme difficulty of discriminating generic from specific charac- 
ters 111 animals presenting such extraordinary cranial variations as the Mexican 
GeoDujida, it is thought best in descriptions of genera, of which only a single species 
IS known, fo record all of the characters that seem entitled to more than specific 
woiglit, The generic diagnosis here given, therefore, errs on the side of fullness. 
The fill lire discovery of additional species will promptly reduce the number of 


maxillary and squamosal arms comiug in contact above it; jugal rudi- 
meutary, inferior and chiefly external; rostrum long and narrow; tem- 
poral impressions meeting in a short but well-developed sagittal crest; 
palatine bones contracted at base of pterygoids; pterygoids vertical 
lamellae as in Thoinomys, meeting or nearly meeting in median line 
behind palate. Premaxilla not inclosing incisive foramina, which is 
bordered posteriorly by the maxilla. 

Mandible rather long and slender, much as in Geomys hursar'ms; 
orbitosphenoids relatively larger than in any other genus of the fam- 
ily, closing the upper part of the sphenoidal fissure (except a foramen 
at apex) and ankylosed broadly with the alisphenoid (pi. 17, fig. 2), as in 
some species of Thomomys; sphenoid fosste corresi^ondingly shortened, 
reaching only halfway from horizontal part of alisphenoid to base of 
cribriform plate; mesethmoid quadrangular, much longer than high 
Cpl. IS, fig. 2) ; endoturbiuals collectively subquadrate, but with antero- 
superior corner rather sharply elongated, projecting into posterior 
emargination of nasoturbinal; the os planum spreading forward in 
front of fourth endoturbiual about as far as length of latter {\A. 10, fig. 4). 

General remarks. — Zygogeomys presents the unique combination of 
distinctly bisulcate incisors with remarkably short sphenoid fossai and a 
type of zygomatic arch heretofore unknown in the whole order Eodentia. 
It presents further an exceptional degree of coossification of the 
component elements of the skull. The occipitals, parietals, frontal, 
ethmoid, squamosals, alisphenoids, maxilla, palatines, and pterygoids are 
ankylosed together ; and the basisphenoid, presphenoid, and orbitosphe- 
noids are ankylosed together. Furthermore, the two resulting complex 
masses are firmly united by ankylosis of the orbitosphenoids with the 
alisphenoids. The coossification is sometimes carried even further by 
the fusion of the anterior and posterior arms of the zygoma, and the 
union of the premaxilla with the maxilla and nasals. The sutures that 
remain open are between the basioccipital and basisphenoid; between 
the frontal on the one hand and the nasals, premaxillaries, and maxil- 
lary root of the zygoma on the other; between the maxilla and 
frontal anteriorly, and maxilla and alisphenoid posteriorly. The 
result of these extensive ankyloses is that in old age all of the 
bones of the cranium except the mandible are inseparably bound 
together — if not directly in every case, then in a roundabout manner. 
Zygogeomys thus occupies an anomalous position in the family. 


(PI. 6; pi. 13, fig. 24; pi. 14, fig. 1; pi. 15, fig. 10.) 

Tj/pefrom Nahuatzix, Michoacan, Mexico. No. 50107 i ad. , U. S. National Museum, 
Department of Agriculture collection. Collected October 11, 1892, by E. W. 
Nelson (original No. 3571). 
Geographic distrihution. — The Sierra Madre of Michoacan, from Patz- 
cuaro to Nahuatzin ; strictly limited to the pine zone, between the alti- 
tudes of 6,800 and 9,500 feet (map 3 =). 


General characters. — Size large; tail rather long, entirely naked from 
base; a conspicuous naked pad at end of nose; fore feet and claws 
shorter than liiud; upper surfaces of both fore and hind feet densely 
covered with hair, completely hiding the skin; color very dark. Cra- 
nial characters marked ; maxillary and squamosal arms of zygoma meet- 
ing above the jugal, which is greatly reduced. 

Color. — Upper parts varying from dark slate to rich seal-brown, 
glossy, and finely mixed with a very thin wash of ferruginous, espe- 
cially on the sides; underparts dark plumbeous washed with fulvous; 
upper surfaces of hind feet slate-gray, sometimes varying to white; an 
irregular patch of white on throat. Some specimens lack the ferrugi- 
nous wash and are glossy slate-black. Some have an almost metallic 

Cranial characters.* — Skull, as a whole, long and narrow; zygomatic 
arches contracted, slender, not expanded at antero-exterual angle; com- 
plete without jugal, which is much reduced in size, the maxillary and 
squamosal arms meeting above itt ; rostrum and nasals long and narrow; 
temporal impressions meeting in a short but well-develoj)ed sagittal 
crest; palatine bones contracted at base of pterygoids; pterygoids ver- 
tical lamellne as in Thomomys; occipital jjlane nearly vertical, about 
twice as broad as high; mastoid bullne fuller and more rounded poste- 
riorly than in Geomys; audital bullae of moderate size, similar to those 
of Geomys hursarius; premaxilla ending below at middle of incisive for- 
amina (instead of surrounding them, as usual in the family) ; postpalatal 
pits rather narrow, elongated and shallow, reaching anterior plane of 
last molar; mandible rather long and slender, much as in Geomys 
hursarius; angular processes moderate; condylar process rather short; 
coronoid process long, its tip overhanging front of condyle. 

Measurements (taken in flesh). — Type specimen, $ ad. : Total length, 
346 ; tail vertebrae, 115 ; hind foot, 40. Average of three adult males from 
type locality : Total length, 342.6; tail vertebrae. 111; hind foot, 45.8. 
Average of seven females from tyi^e locality: Total length, 322.7; tail 
vertebrae, 105.8; hind foot, 42.8. 

For cranial measurements see Table C, p. 209. 

Specimens examined. — Total number 12, from the following localities 
in Michoacan, Mexico: Nahuatzin, 10; Patzcuaro, 2. 

General remarks. — Mr. Nelson found these remarkable animals pretty 
generally distributed over the wooded mountain slopes except where 
the timber is dense. They are most numerous about the borders of 
small grassy parks and in the more open parts of the forest. In places 
where the land has been cleared in these mountains they infest the culti- 

* Owing to tlie circumstance that only a single species of this remarkable genua 
18 known, it is unsafe to attempt to discriminate sharply between generic and spe- 
cific characters. For this reason many of the characters given in the generic descrip- 
tion are here repeated. 
I tin some specimens the union is not quite complete. 




vated fields and do considerable damage to the corn, wheat, and pota- 
toes of the Indian farmers. 

Geuus THOMOMYS Max Wied, 1839. 

(Text fit^s. 31% 32b, aud 68-71.) 

Type TJwmomys riifescens Max Wied. Type locality iiiiknown. 
Thomomya Max Wied, Nova Acta Acad. Caes. Leop. -Carol. Vol. XIX, pt. i., 1839, 

Upper and lower molars, including m^, with two enamel plates each, 
one anterior aud one posterior (figs, 31^ aud 32''). Upper incisor with 
sulcus normally very small and close to inner edge of tooth (fig. 23, p. 
72), or absent. In a few species it is relatively hirge and deep, as in 
T. monticola of Allen. 

Orbital plates of frontal not meeting inferiorly behind cribriform plate 
of ethmoid, but broadly separated by orbitosphenoids (fig. 71, /ro). 

Figs. 68-71.— T7tomom?/s hxdbivorus. ? Salem, Oregon. 

68. Vertical longitudinal section of front of skull, showing turbinated bones. For key see fig. 10. 

69. Vertical longitudinal median section of skull, mesethmoid and vomer in place. For key see fig- 7. 

The accompanying cuts (figs. 68-71) show the relations of the several 
bones forming the floor of the brain case, and also those of the nasal 
chamber, in Thomomys bulbivorns of Richardson. In this s])ecies the 
incisors project much further forward than usual. The various species 
differ considerably iu important cranial characters, as will be shown in 
a special paper on the species of Thomomys. The geographic distribu- 
tion of the group as a whole is shown on n)ap 1, A. 


JAN., 1895.] 



Externally Thomomys differs from all tlie otlier genera of the Geo- 
myida' in tlie relatively small size of the fore feet. In this respect, and 
in the faint sulcation of the incisors, the presence of two enamel plates 
oil each of the molars, above and below, and in numerous cranial char- 
acters it is much less highly specialized than most members of the 

70. Thomomys bulbivonis, from Salem, Oregon. Skull from above ; vault of cranium sawed ofFto show 
floor of brain ease. For key see fig. 9. 

71. Anterior part of floor of brain case, much enlarged. (Same specimen as flg. 70.) 
ale Anterior opening of alisphenoid canal. 

as Alisplienoid l>oue. 

bs Basisi)beiioi<l. 

cr (/ribriform plate of ethmoid, 

/(• Frontal. 

fro Orbital or descending plate of frontal. It should be observed that this plate does not meet 
its fi^llow inferiorly behind the cribriform plate as in most of the other genera. 

of Optic fdriunrn. 

OS Orl)itiis]ili(n<iid. 
ptf Pterygoid fossa. 

sf Upper iiart of sphenoidal fissure. 


(A ) Status of Geomys mexicanus Auct. 

The earliest description that I have seen of any member of tlie 
family GeomyUliv was ])ublislied by Fernandez in 1051, and relates to 
a Mexican aninial called by him the Tucan or Indian mole.* Nearly a 
century and a half later Kerr bestowed the name Borex mexicanus upon 
Fernandez's Tucan without having seen a specimen (Kerr, Animal 
Kingdom, 1792, 207-208). It is not surprising that Kerr followed 
Fernandez and Button in placing the animal among the moles,t misled 
by its projecting incisors and habit of throwing up little mounds of 
earth along the course of its subterranean galleries. 

The animal seems to have been first referred to the genus Geotmjs by 
LeConte in 1852 (Proc. Phila. Acad. Kat. Sciences, 1852, p. IGO). 

In 1827 Lichtenstein described, under the name Ascomys mexicanus^ 
three specimens of pocket gophers collected by Deppe on the table- 
land of Mexico, but the exact locality whence they came is unknown 
(Brants Muizen, 1827, 27-31). The specimens differed greatly among 
themselves in color, as originally described by Lichtenstein, and their 
cranial measurements, kindly famished me by Dr. Matschie, show that 
they belong to at least two different genera. The case as it stands, 
therefore, seems to be as follows : Lichtenstien's mexicanus is composite | 

*Following is a trauslation of the original description: "On the Tucan, or a 
certain kiml of Indian mole. Chap. xxiv. [The Tncan] is apparently a species of 
mole 9 inches in length, and e(iualing the humerus of man in size; it is fleshy, fat, 
and furnished with such short legs that it almost touches the ground with its helly ; 
hair, fulvous; tail, short; claws and nails, long; snout, murine; ears, small and 
round; front [teeth], two above and same in number below, considerably exserted 
and curved inward; [the other teeth], though much smaller, are very strong. When 
fat the flesh is edilde, of pleasant taste, but causes stupor. ' ■ *."— (Francisco 
Fernandez, Historiic Auimalium et Miiicralium Nova' Hispania;, Liber i, 1651, pp. 7-8.) 

tAU the American moles were at that time placed with the shrews in the genus 
■S'ojTJT, the genera Scalops, Scapanits, and Condijlura not having been proposed until 
souietimc later. 

t From the cranial measurements kindly furnished me by Dr. Matschie, and now 
for the tirst time published, it is evident that one of Lichteustein's specimens was a 
Platygeomys closelj related to, if not identical with, the animal here described as 
■P. planiceps. 




[NO. 8. 

and is preoccupied by mexicanus of Kerr (1792). The latter is unident- 
ifiable, the vague description applying equally well to several species. 
It being- clearly impossible to use the name mexicanus, it should be 
dropped from the group. 

Cranial measurements of hco of Lichten stein's ti/pe specimens of Ascomys mexicanus. 
[Measured by Dr. Paul M.itschie.] 



Greatest basal length (condyle to front of premaxilla) . 

Basal length (basion to gnathion) 

Basilar length ot Hensel (basion to alveolus of incisor). 

Greatest zygomatic breadth 

Gre;; breadth posteriorly across squamosals 

Least breadth between postglenoid notches 

Least interorbital breadth 

Height of cranium aliove palate 

Height of cranium above basion 

Length of upper molar series on alveoli 

Length of diastema 

Length of single mandible without teeth 

Breadth across angular processes 

Distance trora condyle to end of angular process 

Breadth across muzzle just in front of zygoma 







9 5 

(B.) Tables of Average Measurements of the Various 


Average measurements of the species of Geomys. 
[All measurements are in millimeters .and from fresh .specimens.] 

Name of species. 

G. bursarius . 

O. hitescens . . 
G. breviceps . . 

G. sagittalis . . 

6. attwateri. . 

G. texensis . . . 
6. arenarmt . 
G. personatus 
G. fallaz 

G. tuza 

G. mobilensis 


Southeastern North Dakota. . . 

Elk River, Minnesota 

Hunter and Williamsville, Mis- 

Western Nebraska* 

Childress, Texas 

Mer Eouce, Louisiana * 

Benton, Arkansas 

Fort Gibson, Indian Territory. 

Miueola, Texas .*. . 

Molano, Texas 

Galveston Bay, Texas ' 

Houston, Texas 

Kockport, Aransas County, 
Texas * ." . . 

Mason, Texas * 

El Paso, Texas * 

Padre Island, Texas* 

South side Nueces Bay, Corpus 
Christi, Texas *. .. ' 

Augusta, Georgia * 

Butler, Georgia^ 

Mobile Bay, Alabama * 

San Mateo, Florida 

Number of 

! <^ 



Hind foot. 



20 : 



8 ■ 


























































220.5, 193. 
216.2 206 
220 I 196 
226 208 








74 63 

84 72 

81. 5 08 

70 I 61 

74 I 66. 3 

68. 2i 61.7 

67. 8, 57. 2 

63. 8: 60. 3 

64 I 54 

64 57 


























34 ' 


' 31 


'Type locality. 

(Average of 28 specimens of both sexes: total length, 210; hind foot, 28. 

ISome of the .specimens of arenarius recorded as females are very large and were probably m.'ileB; 
hence the averages here given for females ari' probably too gieat. 
§The specnuens from Butler. Ga., are clearly intermediate between tuza and mobileiuis. 

JAN., 1895.] 



Average measurements of the species of Craiogeomys. 

LAll measurements are in millimeters and from fresh specimens.] 


Number of 



Hind foot. 

Name of species. 












C. merriami 

Valley of Mexico, Mexico 


















43 5 

42 6 

C. perotensis 

Cofre de Perote, Mexico 


C. oreoeetes 

C. peregrinug 

C. castanops 

Mount Popocatapetl, Mexico . . 
Mount Iztaccihuatl, Mexico... 


Albuquerque, New Mexico 


C. castanops gold 


C. fulveicens 

Cauitas, Zaeatecas, Mexico.... 
Chalchicomula, Puebla, Mexico. 







ios ' 




Average measurements of the species of Platygeomys, Orthogeomys, Heterogeomys, Pappo 

geomys, and Zygogeomys. 

[All measurements are in millimeters and from fresh specimens.] 


Number of 




Name of species. 






d ? 



Platygeomys gymnu- 

P. tylorhinus 

P. planiceps 

Zapotlan, Jalisco, Mexico . . . 

Sierra Nevada de Colima, 
Jalisco, Mexico. 

Tula, Hidalgo, Mexico 

Patzcuaro, Michoacan, Mex- 

N. slope Vole. Toluca, Mex- 
ico, Mexico. 

Colima City, Mexico 

Cerro San Felipe, Oaxaca, 

Mount Zempoaltepec, Oax- 
aea, Mexico. 

Jico, Vera Cruz, Mexico 

Motzorongo, Vera Cruz, 

Chichicaxtle, Vera Cruz 

(type), Mexico. 
Sierra Nevada de Colima, 

Jalisco, Mexico. 
Guadalajara, Jalisco 

Nahuatzin, Michoacan 














































105 9: 


100 91.5 
101.5 91.5 

121 100 

82 7.1 














39 5 

Orthogeomys sealops . . 

Orthogeomys nelsoni. . 

Heterogeomys hispi- 



96. 5 









Pappogeomys bulleri . 

Pappogeomys albi- 

Zygogeomys trichopus 




[no. 8. 

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[Kames of genera and species are in heavy type.] 

Adaptation to subterranean life. 15. 
Alispbenoid bone, 43-45. 
canal, 36,43. 
Ascomys (synonym of (.eoiiiys), 109. 
canadensis, 120, 
niexirauus 2ul . 
Basioccipital, 40. 
Basisphenoid, 43. 
Brain case, floor, 35. 
Callosity, nasal, 16. 
Canal, alispbenoid, 43. 

infraorbital, 39, 55. 
Cheek pouches, 18. 

muscles. 101. 
Color phases, 19. 
Cranial variations, 63-68. 
Cranium. (-SVe Skull.) 
I'ratogeonijs : 

Genus, defined, 150-151. 
Key to species, 151. 
Cratogeoniy i'astanoi)s, 159, 160. 

cranial m e a s u r e - 
meiits, 211. 
castanops goldmani, 160,161. 

cranial iiieas- 
uremeuts, 211. 
estor, 155, 156. 

cranial measurements, 210. 
fulTeseens, 101,162. 

cranial measure- 
ments, 211. 
merrlanii, 151-153. 

cranial measure- 
ments, 210. 
creocetes, 156, 157. 

cranial measurements, 
peregrinus, 158, 159. 

cranial measurements, 
perotensis, 154, 155. 

cranial measurements, 
Cribriform plate, 50. 
Dental armature, 69. 
Digastric muscle, 100. 
Diplostoma (synonym of (ieonijs), 109. 
fusca, 120. 

Dynamics of cutting machine as a whole, 88-97. 
incisors, 89, 90. 
molars, 90-93. . 
Ectoturbinal, 52. 
Enamel in incisors, 70. 
in molars, 78-83. 
in premolars, 78. 
Enamel cap in young teeth, 84-87. 
Enamel organ, 87. 
Eudoturbinal, 52. 
Ethmoid, 50-52. 
Exoccipital, 41. 
Feet, 15. 

Fissui-e, sphenoidal, 36. 
Floor of brain case, 35. 
Food, 19. 

treatment of, 98. 
Foramen ovale, 39, 45. 

rotundum, 39,45. 
Fossa, olfactory, 35. 
pterygoid, 36. 
sphenoid, 35. 
spheno-pterygoid, 36. 
Frontal, 49, 65. 

descending plates, 35, 49. 
Geographic distribution, 26. 

Genus defined, 109-112. 
Key to species, 113. 
Oeoniys arenarius, 139-141. 

cranial measurements, 207. 
breviceps, 129-133. 

craiiial measurements. 205. 
breviceps attwateri, 135-137. 

cranial measure- 
ments, 205. 
breviceps sagittalis, 134. 

cranial measure- 
ments, 205. 
bullori, 147. 

cranial measurements, 214. 
bursarius, 120-127. 

cranial measurements, 204. 
canadensis, 120. 
castanops, 159. 

cranial measurements, 211. 
clierriei, 194. 

cranial measurements, 215. 




(■eoinys cinerea, 120. 
clarkii, 159. 
f^niosu8, 170. 

cranial measurements, 2i;t. 
grandis, 175. 

cr.anial measurements, 214. 
gymnurus, 164. 

cranial measurements, 212. 
heterortus, 186. 

cranial measurements, 215. 
hispidus, 181. 

cranial measurements, 215. 
lutescens, 127-129. 

cranial measurements, 204. 
nierriaiiii, 152. 

cranial measurements, 210. 
mexicanus, 201-202. 

• ci'anial measurements, 202. 
nelsoiii, 147. 
oregoneiisis, 120. 
per!«onatu8, 141-144. measurements, 206. 
fallax, 144-145. 

cranial ineasurements, 206. 
pinetis, 113. 
scalops, 174. 

cranial measurements, 214. 
texensis, 137-139. 

cranial mea-surements, 206. 
tuza, 113-115. 

cranial measuremeuts, 208. 
tuza floridanus, 115-119. 

cranial measurements, 208. 
tuzaiiiobilensis, 119-120. 

cranial measurements, 208. 


Genus defined, 179-180. 
Key to species, 180. 
Heterogeoniysi liispidus, 180-183. 

cranial measureuu^nts. 215 
torridus, 183-185. 

cranial measurements, 215. 
Incisor teeth, 70-72. 

in young, 83. 
Infraorbital canal, 39. 
Interparietal, 41-43. 
Jaw, 60. 

movements, 102-103. 
muscles, 98-101. 
stroke, 97. 
Jugal, 57. 
Key to genera, 23. 

Key to species of Cratogeoniys, 151. 
fteomys, 113 
Heterogeomys, 180. 
Macrogeomys, 186. 
Orthogeomys, 173. 
Pappogeomys, 147. 
Platygeomys, 164. 
Lachrymal, 57. 
Lambdoid crest, 39. 
Macrogeomys : 

Genus defined, 185-186. 
Key to species, 186. 

Macrogeomys clierriei, 193-195. 

cranial measurements, 215. 
costaricensis, 192-193. 

cranial me asu re- 
ments, 215. 
dolichocephalus, 189-192. 

cranial measure- 
ments, 215. 
tieterodns, 186-189. 

cranial measurements, 
Mandible, 60. 

Masseter muscle, 99-100. 

influence on skull, 105-107. 
influence on teeth, 107-108. 
Mastoid bulla, 33, 46-60. 

process, 60. 
Maxilla, 54-56. 
Maxillo-turbinal, 34. 
Meatus auditorius, 33-59. 
Mesethmoid, 50. 
Molar teeth, 74-83. 

in young, 85. 
Morphology of skull, 33-63. 
Month, division into two chambers, 17. 
Mns biirsarins, 120. 
ludoricianus, 120. 
saccatus, 120. 
tuza, 113. 
Muscles, cleido-mastoid, 102. 
digastric, 100. 
external pterygoid, 100. 
internal pterygoid, 100. 
latissimus dorsi, 102. 
masseter, 99-100. 

influence on skull and teeth, 
rhomboideus, 102. 
sterno-niastoid, 102. 
temporal, 99. 

transverse mandibular, 100-101. 
trapezius, 102. 
Muscles of cheek pouches, 101. 
head and neck, 102. 
jaw, 98-101. 
Xarial passage, 39. 
Kasal Itones, 57-58. 
callosity, 16. 
Nasoturbiual, 34. 
Occiput, 05. 
Orbitosphenoid, 48-49. 
Orthogeomys : 

Genus defined, 172-173. 
Key to species, 173. 
Orthogeomys grandis, 175-176. 

cranial measurements, 214. 
latifroiis, 178-179. 
nelsoni, 176-178. 

cranial measurements, 214. 
scalops, 173-^75. 

cranial measurements, 214. 
Os planum, 50. 
Osteodentine, 87. 
Palate, 34. 
Palatine bones, 53. 



Palato-pterygoid jdate, 34. 


fc. Genus defined, 145-147. 

Key to species, 147. 
Pappou:eoiiiys albiiinsus, 147. 

cranial measurements, 
biiUeri, 147-149. 

cranial mea.surements. 214. 
Parietal, 46. 

Paroccipital process, 3.5. 
Periotic capsule, 58-60. 
Phylogenetic tree, 24. 

Genus defined, 102-164. 
Key to species, 161. 
Platygeoinys fumosus, 170-171. 

cranial measurements. 213. 
gyniniiruis, 164-160. 

cranial measurements, 
plaiiioeps, 108-170. 

cranial measurements, 
tylorliinus, 167-168. 

cranial raeasnreraents, 
Postorbital process, 35. 
Pouches, cheek, 18. 

method of filling, 18. 
muscles, 101. 
Premaxilla, 56. 
Premolars, 72-74. 

deciduous, 83. 
permanent, in yoiing, 84. 
Presphenoid, 37, 47. 
Process, angular, 67. 
mastoid, 60. 
paroccipital, 35. 
postorbital, 35. 
Progression backward, 16. 
Psendostoma (synonym of Oeoniys), 109. 
bursarius, 120. 
rastaiiops, 159. 
floridana, 115. 
Pterygoid bones, 52-53. 
muscles, 100. 
plate, external, 36, 54. 
Saccophorns (synonym of Geoiiiys), 109. 

bnrsarius, 120. 
Sagittal area, 39. 
crest, 39. 
Skull, alisphenoid bone, 43-45. 
alisphenoid canal, 36, 43. 
basioccipital l)one, 40. 
basisphenoid bone, 43. 
bony palate, 34. 
changes with age, 61-63. 
coossification of paired bones, 63. 
cribriform plate, 50. 
ectoturbinal bones, 52. 
endoturbinal bones, 52. 
ethmoid bone, 50-52. 
exoccipital bone, 41. 
external pterygoid plate, 54. 
floor of brain case, 35. 

Skull, foramen ovale, 39, 45. 

foramen rotundum, 39, 45. 

frontal bone, 49. 

infraorbital canal. 39 55. 

interparietal bone, 41-43. 

jugal bone, 57. 

laclirymal bone, 57. 

lambdoid crest, 39. 

list of bones, 40. 

mandible, 60. 

mastoid bulla, 31. 

maxilla, 54-56. 

mesethmoid, 50. 

morphology, 33-63. 

narial passage, 39. 

nasal bones, 57-58. 

orbitosphenoid bone, 48-49. 

OS planum, 50. 

palatine bones, 53. 

palatopterygoid plate, 34. 

parietal bones, 46. 

paroccipital process, 35. 

periotic capsule, 58-60. 

postorbital process, 35. 

premaxilla, 56. 

presphenoid bone, 47. 

pterygoid bone, 52-53. 

pterygoid fossa, 36. 

sagittal crest, 39. 

.sphenoid fossa, 36. 

sphenoidal fissure, 36. 

spheno-pterygoid fossa, 36. 

squamosal bone, 45. 

supraoccipital bone, 41 . 

tentorium (absent), 39. 

turbinals, 34, 57. 

turbinated bones, 34, .57. 

tympanic bulla, 33. 

tynipano-periotic capsule, 58-60. 

vomer, 52. 

vomerine sheath, 56. 

zygomatic arch, 34. 
Sorex mexicanus, 201. 
Species, number and distribution, 27. 
in Mexico, 30. 

United States, 28. 
Sphenoid bones : 

Alisphenoid, 34, 43-45. 
Basisphenoid, 33, 43. 
Orbitosphenoid, 34, 48-49. 
Presphenoid, 33, 47. 
Sphenoul fossa, 35. 
Sphenoidal fissure, 36. 
Spheno-pterygoid fossa, 36. 
Squamosal, 45. 
Supraoccipital, 41. 
Tail, an organ of touch, 16. 
Teeth, 69-88. 

changes from wear, 86-87. 

dental formula, 69. 

dynamics, 88-97. 

of cutting machine as a whole, 
incisors, 89, 
molariform teeth, 90-97. 

enamel, 78-83. 



Teeth, enaDiel, dynamics, 93-97. 
incisors, 70-72. 

dynamics, 89. 
young, 83. 
manner of attachment, 88-90. 
molars, 74. 

dynamics, 90-93. 
enamel plates, 78-80. 
young, 85- 87. 
last upper molar, 76-77. 
enamel, 78-83. 
premolars, 72-74. 

deciduou.s, 83. 
enamel plates, 78. 
permanent young, 84. 
Temporal impression-s, 39, 42. 

muscle, 99. 
Tentorium (absent), 39. 

Thoiiioniys, 198-199. 

Tongue, 18. 

Turbinals, 57. 

Tympanic bulla, 33, 58-59. 

Tympano-periotic capsule, 58-60. 

Typo localities, 25. 

Variation : 

Cranial, 03-68. 

Individual, 21. 

Seasonal, 20. 

Sexual, 20. 
Vomer, 52. 

Vomerine sheath, 56. 
Zygogeomys, genus defined, 195-196. 
Zygogeomys trichopus, 196-197. 

cranial measurements, 209. 
Zygomatic arch, 34. 



platj: 1. 

(All natural size.) 

Geoviyshur sari IIS (Shaw). Knoxville, Iowa. 
(No. 2772 (? ad. Merriam collection.) 

North American Fauna, No. 8. 

Plate I 

Senj. Mortimer, del 

Geomys bursarius (Shaw) 
Knoxville, Iowa. 

No.2772. tfad. 

B Meisel, pf^tc kch 



(All natural size.) 

Cratogeomijs merriami (Thomas). Lerma, Mexico. 
(No. 50110 S ad. U. S. Nat. Mus.) 

North American Fauna, No. 8. 

Plate 2. 

¥at .size. 

Geomys merriami Thomas 
Lerma, Mexico. 

No. 50110. o- ad. 

B Metsel. pAete. HA. 



(All natural size.) 

Platiifjeoinys fiymnurus Merriam. Zapotlaii, Jalisco, Mexico, 
(,No. 45611 ^ ad. U. S. Nat. Mus.} 

North American Fauna, No. 8. 

Plate 3 

B Mflzssl. photo liin 

Geomys gymnurus Merriam 

Zapotlan, Mexico. 

No.^SSII.a" ad. 



(All natural size.) 

Heterogeomys hispidus (LeCoute). Jico, Vera Cruz, Mexico. 
(No. 55343 U. S. Nat. Mus.) 

North American Fauna, No. 8. 

Plate 4 


B-M'ftset, photo litk 

Geomys hispidus. LeConte 
Jico.Vera Cruz. Mexico. 

No, 55343. <? ad. 


(All natural size.) 

Macrogeomys dolichocephahis sp. nov. San Jose, Costa Rica. 
(No. 36295 (? ad,, U. S. Nat. Mus.) 

North American Fauna, No. 8. 

Plate 5 


San Jose', Costa Rica. 

No 36295. 



(All natural size.) 

Zygof/eomys irlcliopus sp. nov. Nalmatziu, Micboacaii, Mexico. 
(No. 50107 i ad., U. S. Nat. Mus.) 

North American Fauna, No. 8. 

Plate 6 

Geomys trichopus Merriam 
Nahuazin.Michoacan, Mexico. 

B Affzsei. pho^o Hch 


(All iKitnral size.) 

1. (ieomjia tma (Ord) ^ ad. Augusta, Ga. (Type locality). 

(No. 58639 U. S. Nat. Mus.) 

2, 5.6. (i. Iiiza mohihnsis ^ ad. Mobile Bay, Alabama. (Tyjte locality 

(No. 46024 U. S. Nat. Mus.) 
3 and 4. G. tuza fioridaintu ^ ad. 8an Mateo, Fla. 

(No. 6512 c? ad. aud 6514 ^ old, Merriam collection.) 

North American Fauna, No. 8. 

Plate 7 



platp: 8. 

(All iiaturul size) 

1 &■ 2. Cralogeomys oreocefes sp. nov. 9 iul. Mount I^opocatapetl, Mexico. Ti/jje. 

(No. 57963 U. S. Nat. Mus.) 
3. C. pcretjrinu.s HI), iiov. 9 ad. Mount Iztaccilmatl, Mexico. Tii2)e. 

(No. 57964 U. S. Nat. Mus.) 
4 & 5. C. estor sp. uov. Las Yigas, YGVix i'vnz, Mexico. 

(4 = No. 54306 9 ad. and 5 =54308 <? ad. U. S. Nat. Mus.) 
6. C. perotens'is sp. uov. 9 ad. Cofre de Perotc, Vera Cruz, Mexico. 

(No. 54299 II. S. Nat. Mus.) 

North American Fauna, No. 8. 

Plate 8 

B Meisel. phtih Uch 

4S&5c'G. ESTOR 

3 ? ad. G. PEREGRINUS 
6 ? ad. G. PER0TEN5I5 


(All uiitiiral size.) 

1. Geoniys arenariiis ^ ad. El Paso, Texas. 

(No. 58339 U. S. Nat. Mus.) 

2. G. texensis $ Mason, Texas. 

(No. 4161 Merriam collection.) 

3. G. atttvateri ^ ad. Rockport, Aransas County, Texas. 

(No. 51382 U. S. Nat. Mus.) 

4. Gr. sagittalis ^ ad. Galveston Bay, Texas. 

(No. 44957 U. S. Nat. Mus.) 
5 & 7. G. lutescens ^ ad. Cherry County, Nebraska. 

(5 = 25640 <? yg. ad.; 7=25471 <? old, U. S. Nat. Mns.) 
6. G . breviceps $ ad. Mcr Rouge. Louisiana. 

(No. 46673 U. S. Nat. Mus. ) 

8. G. biirsarhis 9 3,d. Knoxville, Iowa. 

(No. 2024 Merriam collection.) 

9. <T, bitrsarius $ ad. Knoxville, Iowa. 

(No. 2625 Merriam collection.) 

North American Fauna, No. 8. 

Plate 9 

BMfZsei. phatc lith 

5&7.G. LUTESCENSo-ad 6,G. BREVICEPSo'ad. 8 5 ad.9o-ad. G. BURSARIU5 


PLATE 10. 
Under side of mandible. 

(All natural size.) 

1. Geomys iuza flnridauus (Baelnnaii). San Mateo, Florida. 

(No. 6511 (? Merriam collection.) 

2. G. tuzamobilcnsis HT[>. nov. Mobile Bay, Alabama. 

(No. 46023 (? U. S. Nat. Mns.) 

3. Cralof/eomys oreocetes sp, nov. Mount Popocata]ietl, Mexico. 

(No. 57963 5 U. S. I\at. Mus.) 

4. C. peregrinits sp. nov. Mount Iztaccilmatl, Mexico. 

(No. 57964 $ U. S. Nat. Mus.) 

5. C. merriami (Thomas). Amecameca, Mexico. 

(No. 57970 <? U. S. Nat. Mus.)- 

6. Geomys btirsariiis (Shaw). Knoxville, Iowa. 

(No. 2772 (J Merriam collection.) 

7. Macroyeomys dolichoccphalus sp. nov. Sau .lose, Costa Rica. 

(No. 36295 ^ U. S. Nat. Mus.) 

8. Platyyeomys yymnuriis Merriava. Zapotlan, .Jalisco, Mexico. 

(No. 45611 J U. S. Nat. Mus.) 

North American Fauna, No 

Plate 10 


242 NOltTU AMERICAN FAUNA. [no.8. 

PLATE 11. 

(All inilnral size.) 

1. VappoaeonuiH hnUeri (Thomas), ^^ierra Nevada de Coliiiia, .Jalisco, Mexico. 

(No. 4.5(>22 i U. S. Nat. Mus.) 

2. MacrofjeomijHheterodus (VateTH). Costa Kica, Mexico. 

(No. c? U. S. Nat. Mus.) 

3. HeterogeoiiiijH costaricenHis sp. nov. Pacuare, Costa Rica. 

(No. 225.51, sex ?, U. S. Nat. Mus.) Tyj)'!. 

4. Plaiyf/eomnHfumosus Merriam. Coliuia City, Mexico. 

(No. 4.5211 <? U. S. Nat. Mus.) 

5. Ortliof/eomijs latifrons fill. nov. Guatemala. 

(No. , sex ?, U. S. Nat. Mus.) Tt/pe. 

6. O. latifrons (uuder side of maiulil>le of sauie skull as 5.) 

North American Fauna, No. 8. 

Plate 11 


B.ifeiseU ph^to Int^ 

1.GE0MY5 BULLERI - 2. G. HETER0DU5 '/ 3. G . C05TARICEN 51 5 


PLATE 12. 

(All natural size.) 

Cratogeomys castanops (Baird). Las Auiiuas, Colorado. (Type locality.) 

(No. 47368 ^ U. S. Nat. Mus.) 

1". Basioccipital of same specimen. 
Cratogeomys fulvescens sp. nov. Chalcliicomula, Mexico. (Type locality.) 

(No. 53498 <? U. S. Nat. Mus.) 

2". Basioccipital of same specimen. 
Geomys persovai us fallax suhs]). nov. Corpus Christi, Texas. Ty2}e. 

(No. 43845 ^ ad. U. S. Nat. Mus.) 

3". Left audital bulla of same skull. 
Geomys personatus Tvne. Padre Island, Texas. (Type locality.) 

(No. 43294 ^ U. S. Nat. Mus.) 

4*. Left audital bulla of same skull. 

North American Fauna, No. 8. 

Plate 12 




PLATE 13. 
Left zygoma, showing variations in jugal bone. 

(All natural size.) 

1. riatygeomys tylorhinm sp. nov. Patzcuaro, Mexico. 

(No. 47183 S U. S.Nat. Mus.) 

2. r. gymnnrus Merriam. Zapotlan, Mexico. 

(No. 45611 (? U.S. Nat. Mus.) 

3. P. plan iceps s]^. nov. Tula, Hidalgo, Mexico. 

(N0.559U6 <? U.S.Nat. Mus.) 

4. Cratogeomys merriami (Thomas). Lerma, Mexico. 

(No. 50110 <? U.S.Nat. Mus.) 

5. C. perotensis sp. nov. Cofre de Perote, Mexico. 

(No. 54295 9 U.S. Nat. Mus.) 

6. C. estor sp. nov. Las Vigas, Mexico. 

(No. 54308 <? U.S. Nat. Mus.) 

7. C. estor sp. nov. Las Vigas, Mexico. 

(No. 54306 9 U. S. Nat. Mus. ) 

8. C. oreoceteH sp. nov. Mount Popocatapetl, Mexico. 

(No. 57963 9 U. S. Nat. Mus.) 

9. Geomys fnza (Ord). Augusta, Georgia. 

(No. 63842 S U. S.Nat. Mus.) 

10. G. tuza floridanus (Aud. and Bach.). San Mateo, Florida. 

(No. 6514 ^ Merriam collection.) 

11. G. buraarius (Shaw). Knoxville, Iowa. 

(No. 2624 (? Merriam collection.) 

12. G. texensis sp. nov. Mason, Texas. 

(No. 4161 ^ Merriam collection.) 

13. G. arcnarhi8 sp. nov. El Paso, Texas. 

(No. 25015 J U. S. Nat. Mus.) 

14. G. personatusTrwd. Padre Island., Texas. 

(No. 43294 ^ U. S. Nat. Mus.) 

15. Papjmgeomys hulleri (Thomas). Sierra Nevada de Colima, Mexico. 

(No. 45618 9 U. S. Nat. Mus.) 

16. Orthogeomys latlfrons sp. nov. Guatemala. Type. 

(No. U. S. Nat. Mus ) 

17. Cratogeomyscastanops {Y^a^x^). Las Animas, Colorado. 

(No. 47368 <? U. S. Nat. Mus.) 

18. Macrogeomysheterodtis (Peters). Costa Rica. 

(No. U. S. Nat. Mus.) 

19. Macrogeomys dolichocephalus sp. nov. San Jose, Costa Rica. 

(No. 36295 <? U. S. Nat. Mus.) 

20. Heterogeomys Mspidua (LeConte). Jico, Vera Cruz, Mexico. 

(No. 55343 $ U. S. Nat. Mus.) 

21. Heterogeomys torridus sp. nov. Guatemala. 

(No.. — S U. S. Nat. Mus.) 

22. Macrogeomys eherriei (Allen). Santa Clara, Costa Rica. 

(No. 664 im. Costa Rica Nat. Museum.) 

23. Macrogeomys costaricensis sp. nov. Pacuare, Costa Rica. 

(No. 22551 im. U. S.Nat. Mus.) 

24. Zygogeomys Irichopua sp. nov. Nahuatzin, Michoacan, Mexico. 

(No. 50107 c? U. S. Nat. Mus.) 

North American Fauna, No. 8. 

Plate 13 




Nat size 

B Meisel phah bh 



TUZA d" 


CA5TAN0P5 .^• 
























HISPIDUS .(form) 


E5T0R >/ 


















PLATE 14. 
Posterior molars and palatopterygoids. 

(All double natural size.) 

1. Zi/f/of/eomys trichopus sp. nov. Nahuatziu, Michoacan. Mexico. 

(No. 50107 c? U. S. Nat. Mus. ) 

2. Geouii/s hi(rsariiis (Shaw). Knoxville, Iowa. 

(No. 2624 cJ Merriain collection. ) 

3. Macrof/eojnys helerodas (Peters). Costa Rica. 

(No. U. S. Nat. Mus. ) 

4. Gcomys pemonatns True. Padre Island, Texas. 

(No. 43294 (? U. S. Nat. Mus. ) 

5. Geinnijii peraonatun fallar subsp. uov. Corpus Cliristi, Texas. 

(No. 43292 9 U. S. Nat. Mus. ) 

6. Cratogeomiis castdiiopn (I5aird). Las Animas, Colorado, 

(No. 47368 c? U. S. Nat. Mus. j 

7. Cralogeomijs mvrriami (Thomas). Lerma, Mexico. 

(No. 50110c? U. S. Nat. Mus. ) 

8. Flatyfjeomiis fumosus Merriam. Colima, Mexico. 

(No. 45213 c? U. S. Nat. Mus. ) 

9. Plat\igcomy>i planicepn sp. nov. Volcan Toluca, Mexico, 

(No. 55906 i U. S. Nat. Mus. ) 

10. Macrogeomi/8 cosfaricciD^iii sp. nov. Costa Rica. Type. 

(No. 22551 U. S. Nat. Mus.) 

11. rappogeoniys httlleri (Thoiuas). Sierra Nevada de Colima, Jalisco, Mexico, 

(No. 45618 5 U. S. Nat. Mus. ) 

12. Ileteroyeomyn hispidus (LeConte). .lico. Vera Cruz, Mexico, 

(No. 55017 9 U. S. Nat. Mus. ) 

13. Geomys texeiisis sp. nov. Mason, Texas. 

(No. 4168 9 Merriam Collection. ) 

14. Geomys liitmccns Merriam. Woodward, Oklahoma. 

(No. 48566 (? U. S. Nat. Mus. ) 

15. Geomys tn~a inobilensis sp. nov. Mobile Bay, Alabama. 

(No. 46025 J U. S. Nat. Mus. ) 

16. Geomys tuza jloridanus (And. and Bach.). San Mateo, Florida. 

(No. 6511 1? Merriam Collection. ) 

North American Fauna, No. 8. 

Plate 14 

i ^^ 


BUHSARius (Shaw) 
HETER0DU5 Peters 

PER50NATU5 Tfue 
CA5TAN0P5 Bait'd 

MERRiAMi Thomas 
FUM05US Merriam 

B Afeisel. pho to U(h 

9. G. PLANICEP5 nob. 

10. C05TARICEN5I5 nOb. 

11. BULLERi Thomas 

12. HI5P1DU5 LeConte 

13. TEXEN5I5 nob. 

14. LUTESCENS MeiTiam 

15. M0B1LEN5I5 nOb. 

16. TUZA FLORlDANUS(BaCl"llTian) 

2r)0 NORTH AMERICAN FAUNA. [no. 8. i 


PLATE 15. 
(All n.itnral size.) 

1. Macrof/eonujs cherriei (Allen). Santa Clara, Costa Rica. 

(No. 664 iiii Museo Nacional de Costa Rica). Type. 

2. netcrogeomys torridus sp. iiov. Cliichicaxtle, Vera Cruz. Mexico, 

(No. 63629 9 ad. U. S. Nat. Mus.). Type. 

3. Occiput of Macrogeomys dolichocephalus sp. nov. San Jose, Costa Rica, 

(No. 36295 (? ad. U. S. Nat. Mus.). Type. 

4. Occiput of Heierogeomys liispidus (LeCoute). .Tico, Vera Cruz, Mexico. 

(No. 55343 <? ad. U. S. Nat. Mus.) 

5. Occiputof Pappogcomys hidleri (Thomas). Sierra Nevada- de Col inia. .Jalisco, Mex- 

ico. (No. 45618 9 yg. ad. U. S. Nat. Mus.) 

6. Occiput of CVrt/or/eowu/s werrirtmi (Thomas). Lcrma, Mexico. 

(No. 50110 c? ad. U. S. Nat. Mus.) 

7. Occiput of I'latygeomys gymnuriis Merriam. Zapotlau, Jalisco, Mexico. 

(No. 4.5611 S ad. U. Nat. Mus.) 

8. Upper incisors of Macrogeomys dolichocephalus. 

9. Upper incisors of Crafogeomys merriaml. 

10. Ujiper incisors of Zygogeomys frichopus. 

11. Upper incisors of Geomys hursarius. 

12. Upper incisors of Geomys tuza. 

North American Fauna, No. 8. 

Plate 15 

Mezsel, pho(c iith 

10. G. TRICH0PU5 II G. BUR5ARIU5 12, G. TUZA. 


PLATE 16. 
1 and 2. Hetcrogeomys iorrUhis jiiv. Motzorongo, Mexico (No. 636-43 IT. S. National 
Molariforin teeth, showiiij;' deciduous premolars in situ; also unworn m 3, and 
immature pattern of crowns in m 1 and 2. 

1. Left upper series. 

2. Left lower series. 

Ix. Permanent upper jjremolar, uncovered to show unworn enamel 

a, Permanent premolar not yet in place; h, deciduous premolar; c, 
third u])per molar; d, third lower molar. 
3, 4, and 9. Geomi/i^ hiirsdriiis ]nv. Elk River, Minn. (No. 4909 Merriam coll.) 

Molariform teeth, showing- deciduous premolars in situ; also unworn m 3, and 
immature pattern of crowns in m 1 and 2. 

3. Left upper series. 

4. Left lower series. 

4x. Transverse section of m; about three-fourths down, showing that 
the tooth is a single prism below, and that the enamel is confined 
to its posterior border. 

9. Left lower series from outer side, showing relations of permanent and 

deciduous premolar, bilophiodont crown of mj, and forms of mi 
and lUo (which show the manner in which the change occurs from 
the double prism above to the single prism below). 
a, Permanent premolar not yet in place; b, deciduous premolar; c, 
third upper molar; d, third lower molar. 
5, 6, and 7. Heierocjeomys torridus juv, (same specimen as in fig. 1). 

Right upper premolar, showing unworn enamel cap and relations of enamel 
and cement. The cement bands are shaded. 

5. Outer side of tooth. 

6. Inner side. 

7. Posterior face. 

a, Outer cement band of anterior prism; h, postero-external cement 
band of posterior prism; c, inner cement band of posterior prism; 
d, inner cement band of anterior prism ; e, lower end of enamel, 
showing position of enamel organ. 
8. Mncrof/eomi/s lieterodus ad. 

Right upper premolar, s^^owini;' relation of cement bauds (unshaded) to enamel 

(shaded) ir atur" tooth after the enamel cap [shown in figs. 5, 

6, and 7] has w" . ,ft'. 

10 and 11. Zygogeomijs trichopns ^vw . Nahuatzin, Mexico (No. 50104 U. S.Nat. Mus.). 

Crowns of molariform series showing permanent enamel pattern and 'osteo- 

dentine' islands. 

10. Left ui)per series. 

11. Left lower series. 

12 and 13. Jhterogeoiinjs liisjjidus ad. Motzorongo, Mexico. 

Right upper premolar, after the enamel cap of the young tooth has worn off, 
showing permanent enamel pattern. 

12. Outer side of the tooth (should be compared with 5, whichshows same 
side of same tooth before the wearing down of the enamel cap begiiib). 

13. Crown of same tooth. 

a. Outer cement band of anterior prism. 
h. Postero-external cement band of posterior prism. 
Shaded bauds show the enamel. 
14-17. Vruiogeomys cantanops i\w. Las Animas, Colorado. 

14 and 15. A very young individual, but older than Nos. 1 and 4. The 
deciduous premolars have been shed, but the enamel caps of the 
permanent premolars (a) and the last true molars (m^c and mjd) 
have not yet worn down far enough to show the enamel pattern of 
the adult tooth (which may be seen in figs. 16 and 17). The crown 
of the last lower molar (d) is still a double prism. 
16 and 17. Another immature individual of the same species, but enough 
older than 14 and 15 to show the permanent form and enamel pat- 
tern of the adult teeth. 
18 and 19. Geomys hiirsnrius ini. Elk River, Minnesota. 

Crowns of molariform series showing permanent enamel pattern. 

18. Left upper series. 

19. Left lower series. 

20 and 21. Macvogeomys cherriei im. Santa Clara, Costa Rica. Type. 

Crowns of molariform series showing permanent enamel pattern. 

20. Left upper series. 

21. Left lower series. 

North American Fauna, No. 8. 

Plate 16 

.. .r:-i^--ofa B Mersel. phalo Ink 

1.2.5,6,7, IE & 13 Heterogeomys hispidus 3,4.9,18 & 19. Geomys bursarius 


I4,I5.I6&I7 Cratogeomys CASTANOPS ZOSc ZI.Keterogeomys cherriei 




PLATE 17. 

(All natural size.) 

Skulls seen from above ; vault of cranium cut away, showing door o 

brain case. 

1. Hetcrogeomtia torridus. Motzorongo, Vera Cruz, Mexico 
2- Ziiyogeomijs Irichopus. Nahuatzin, Michoaeau, Mexico. 

3. Geomys hitrsarius. Portland, North Dakota. 

4. riati/geoviiis t/yinuunis. Zapotlan, .Jalisco, Mexico. 

5. Cratof/eomys merriami. Amecauieca, Valley of Mexico. 

Key to pi. 17. 

tV Hva 

Fia. 9. — Young skull of Cratogeomys merriami, vault of cranium cut to show floor of brain cage, 

ae Anterior opening of alispbenoid can 

as Alisphenoid bone. 

bo Basioccipital. 

bs Basispheuoid. 

f Condyle of exoccipital. 

cr Cribriform plate of ethmoid. 

em External auditory meatus. 

ex Exoccipital. 

// Floccnlar fossa. 

fr Frontal. 

fro Descending or orbital plate of frontal (the 
animal is so young that theplate.s of the 
two sides have not yet united below). 
■;' Jugal. 

I Lachrymal. 

ma Meatus auditorius internus, 

mb Mastoid bulla. 

n Nasal. 

of Optic foramen. 

OS Orbitosphenoid. 

pet Petrous part of periotic. 

pm,z Ascending arm of premaxilla. 

ps Presphenoid. 

ptf Spheno-pterygoid fossa. 

sf Apex of sphenoidal fissure. 

SO Snpraoccipital. 

sq Squamosal. 

^6 Superior face of tympanic or audital bull 

zmx Zygomatic root of maxilla. 


North American Fauna, No. 8. 

Plate 17 

BM^zseLpho'c 'M 


3. Geomys BUR5ARIU5 (Shaw) 4. Platygeomys gymnurus (Merriam) 
5 Cratogeomys merriam I (Thomas) 



I NO. 8. 

PLATE 18. 
(All natural size.) 

Vertical median longitiidiiial section of skull (mesethmoid and right 
half of vomer in place). 

1. Geomys hiirsariits $ . Kuoxville, Iowa. 

2. Zijiiocicomy^ trichopus 9. Naluiatzlu, Mirhoacan, Mexico. 

3. Heieroyeonn/.s torridus ^. yg. ad. Motzorongo, Vera Cruz, Mexico 

4. Cndof/eomys merriami $ . Tlalpam, Valley of Mexico. 

5. riatygeomys (jymnurus ^ . Zapotlau, Jalisco, Mexico, 

Key to pi. 18. 

Fig. 7. — Longitudiual vertical median section ot skull of Crator/eomys merriami, showing interior 
of brain case and nasal chamber. Vomer and mesethmoid in place. 

pa Parietal. 

pet Petrous part of periotic capsule 
2)1 Palatine. 
pinx Premaxilla. 
p.i Prcsphenoid. 

Tympanic bulla, (antero-superior part, 
■wliich alone appears within the brain 

Vomerine sheath of maxilla. 
First endoturbinal (Below and somewhat 
behind it the anterior ends of the sec- 
ond, tliird, and fourth cndotiu'bjnals 
may be seen.) 


Anterior palatine foramen. 


Incisive foramen. 


Meatus auditorius internus. 


Floccular fossa. 


Upper part of sphenoidal tissure. 








Condyle of e.xoccipital. 




Haraular process of pterygoid. 




Mesethmoid plate. 










Lower border of os planum. 



North American Fauna, No.8. 

Plate 18 


B Mfi^eU pfutp luh 




PLATE 19. 

(All natural size.) 

1. Orthogeomys scalops 9 ad. Oaxaca, Mexico (skull from above). 

2. Orthogeomijs scalops 9 a-d. Same specimen (l»ase of cranium). 

3-7. Median longitudinal section of nasal chamber (vomer and mesetbmoid removed) 
showing turbinated Ijones. 

3. Geomys bm'sariiis ^ . Knoxville, Iowa. 

4. Zygogeomi/s trichopus 9 • Nahuatzin, Michoacau, Mexico. 

5. Heterogeomys forridiis J . Motzorongo, Mexico. 

6. Cratogeomys mcrnami ^ . Tlalpaia, Valley of Mexico. 

7. Platygeomys gymnitrus J. Zapotlan, Jalisco, Mexico. 

Key topi. 19. 

n\ It ;i^t 

Fig. 10. — Longitudinal vertical median section of front part of skull of Oeomys bursarius. 
moid and. vomer removed to show turbinated bones. 


1 Anterior palatine-foramen. 
3 Incisive foramen. 

3 Vacuity in front of pre.spheDoid (present in Oeomys bursarius and tuza only. It is partly over- 

lapped posteriorly:by the ascending wing of the vertical plate of the palatine, ap.). 

4 Presphenoid fenestrum. Present in all species. 

5 Upper part of sphenoidal fissure. 
It First or superior endoturhiual. 

2t Second endotiirbinal. 

3t Third endoturbinal. 

it Fourth endoturbinal. 

ap Ascending wing of vertical plate of palatine. 

fr Frontal. 

mt Maxillo-turbinal. 

mic Maxilla (the upper pointer rests on the maxillary .surface of the narial passage, the lower on the 

sawed body of the bone). 
n Nasal. 
nt Naso-turbinal. 
op Os planum. 

pi Palatine (the upper pointer rests on the palatine face of the narial passage, the lower ou tlie 
sawed horizontal body of the bone). 
pmx Premaxilla. 
ps Presphenoid. 
vr Vomerine ridge of os planum (unites with the lateral wing of the vomer). 

North American Fauna, No. 8. 

Plate 19 

FtTidUr, M. B Mfisel phot:, UiK 


NoBTH Amebican Fauna, No 

Maps 1 <fe 2. 


B DISTRIBUTION OF GENUS OEOMTS (B = G. buraanua group ; B'= G. 
tuza group.) 


[All double natural size.] 

Figs. 1- 3. Sorex {Atophyrax) hendirii palmeri. Oregon City, Oregon. Type. 
(No. 56898, U. S. Nat. Mus.) 
4- 5. Sorex {Microsorcx) hoyi. Elk River, Minn. 

(No. 2520, Merriam collection.) 
()- 7. Sorex calif ornicus. Walnut Creek, Contra Costa County, Calif. 

(No. 44428, U.S. Nat. Mus.) 
8- 9. Sorex ienelbis. Lone Pine, Owens Valley, California. Type. 

(No. 32495, U. S. Nat. Mus.) 
10-11. Sorex merriami. Fort Custer, Mont. Type. 

(No. 4861, 2 , Merriam collection.) 
12-13. Sorex macrodov . Orizaba, Vera Cruz, Mexico. Type. 
(No. 58272, <?, U. S. Nat. Mus.) 


Noilh American Fauna, No 10 

Plate XII 

1-3. Sorex bendirii 2'alvier/. (1,7. 8. californicus. 10,11. S.merriami. 

4.5. S.hoyi. H.O. S.tenellus. 12,13. S.macrodon. 



Bridled Weasel, Putorius frenatus. 
Valley of Moxico 


Black-footed Ferret, Putorius nigripes 

Western Kansas. 




N^o. 11 

[Actual (late ofpublicatiou June 30, 1896] 





18 90 


U. S. Department of Agriculture, 

Washington, D. C, ilfay 9, 1896. 
Sir: I have the lioiior to traiisinit herewith for publication, as Ko. 
11 of North American Fauna, a Synopsis of the Weasels of North 

Respectfully, C. Hart IMerriam, 

Chief of Division of Ornithology and MammaUxjy. 
Dr. Chas. W. Daeney, Jr., 

Acting Secretari) of Agriculture. 



Iiitioductiou 5-7 

Siibjifeints Putoriiis (the ferrets) 7-9 

Subgenus Ictis (the weasels) 9 

List of North American weasels 10 

Descriptions of species - , 10-32 

Table of cranial measurements '63 


(All natural size.) 


Frontispiece. Heads of Black-footed Ferret and Bridled Weasel. 

1. Skulls of Putoriiis nigripes and F. putorius. 

2. Skulls of rutoriiis arciicus, alascensis, c'lvoytnmi, streatori, and rixosiis. 

3. Skulls of Putorhts frcnaius, lonnicauda, and tropiculis. 

4. Skulls of Puiorius noi'eboraveiisis, rvashingtoni, iwul jieninanhi. 

5. Skulls of Putoriiis longicauda, cicognani, iiocchoracensifi, rixosiis, j^eninsuhr, and 



1. Puiorius nigrijics, ,} old. Trego Count j^, Ivans. 

2, 3. Putorius cicognani, ^ ad. Elk liiver, Minnesota. 

4-6. Putorius vuvchoracensis, $ ad. Adirondacks, New York. 
7-9. Putorius longicauda, ^ ad. Fort Sisseton, S. Dakota. 
10, 11. Putorius longicauda sjyadix, J . Elk River, Minnesota. 
12-14. Putorius arizoncnsis, $ ad. Boulder County, Colo. 

15. Putorius freiiaf us, 9 ud. Cofre de Perote, Vera Cruz. Mexico. 

16. Putorius tropicalis, $ ad. Jico, Vera Cruz, Mexico. 





By C. Hart Merriaaf. 

The preseut sj-nopsis includes the one ferret and all of tlie weasels 
yet d iscovered in jSTorth America north of Panama. Of the true weasels 
(subgenus Ictis ) no less thau 22 species and subspecies are here recog- 
nized, 11 of which are described for the first time. 

Until very recently the group has been in a state of chaos, but now, 
thanks to Outram Bangs's excellent paper entitled ^A review of the 
weasels of eastern Nortli America," the obscurity that has so long- 
surrounded our eastern species has been cleared away and the task of 
revising the whole group is rendered comiiaratively easy. Additional 
material is needed from certain parts of the West, particularly from 
southeastern Alaska and the middle and northern parts of the Great 
Basin, and much remains to be learned respecting the extent to which 
intergradation exists between allied forms having contiguous ranges. 

Excepting the circumpolar type, represented in America by the weasel 
of the barren grounds {ruforixs arcUcus nob.), and in Eurasia by the 
closely related P. erminea, the weasels of North America fall naturally 
into two groups, characterized by important cranial differences, and 
having com])lementary geographic ranges. The first is a boreal group 
comprising five forms: richordsoni, alascensis, cicognani, streatori, and 
rixosKS, the southernmost of which {cicognani) reaches only the northern 
United States. The other is an austral group comprising tlwfrcnatiia 
and longicauda series and including P. peninsula', of Florida. Of this 
series only a single species (P. arizonen.ns) reaches the lowermost of the 
boreal zones, and this only in the mountains. 

Between these two groups are two very interesting species, novehora- 
censis and irojjicalis — the former inhabiting the eastern United States, 
the latter the tropical belt of Mexico. Mr. Bangs has already shown 
that the female of P. 7ioreboracensis resembles P. cicognani, while the 
male resembles P. longicauda. The case of P. iropicalis is exactly 
parallel, the female resembling cfcognani, while the male resembles 

' Proc. P.iol. Soc. Washington, X, pp. 1-24, Feb. 25, 1896. 


Among mammals the female is often less specialized than the male 
and consequently bears more resemblance to the ancestral stock, thus 
giving a clew to the line of descent when this can not be determined 
from the iiuile alone. In the present instance the females of novehora- 
censis and tropieaJis have small, smoothly rounded skulls without sagit 
tal crests and with narrow audital bulhe and inflated squamosals, as 
in the cicognani series, wiiile the males have large angular skulls with 
well-developed sagittal crests, relatively broad audital bulhe, and iiat 
squamosals, as in the loiif/icauda-frenatus series. The inference is that 
the austral longivmuhi-frenatus series was derived from the boreal 
cieognani stock, and that the differentiation took place in the South. 
P. norehoraeensis occupies middle ground geographically, and may have 
become differentiated from cicognani under existing conditions in the 
area it now inhabits; but P. fropicalix, which inhabits tropical Mexico, 
must either have originated from the cicognani stock when the latter 
was driven southward by the cold of the Glacial epoch, or must have; 
accomplished a very remarkable migration. 

Turning now to the weasel of the tundras {F. arcticus), the female is; 
also found to resemble the cicognani type, indicating — at least so far 
as the American species go — that the whole group (subgenus Ictis) has 
si^rung from an ancestral type related to 7*. cicognani. 

Probably cicognani itself is a strongly specialized ty])e, although the 
specialization took place a long time ago and seems to have been in 
the direction of greater simplicity. The tendency has been toward a 
narrowing of the skull as a whole and the obliteration of its promi- 
nences and angles. The zygomata have been reduced and drawn in 
close to the sides of the cranium, and the brain case has been nar- 
rowed, elongated, and smoothly rounded off, as if to enable the head to 
pass through small openings. The body as a whole has undergone 
parallel modification, presenting the extreme degree of slenderness 
known among the mammalia. This type of weasel seems to have been 
developed for tlie express purpose of preying ui)on field mice or voles, 
its narrow skull and cylindrical body enabling it to enter and follow 
their runways and subterranean galleries. The extreme development 
of the type is presented in P. rixosus and P. streatori^ whose exceed- 
ingly small size and almost serpentine form make it possible for them 
to traverse the burrows of even the smaller mice. 

It is an interesting fact that the geographic range of the cicognani 
group is almost coincident with that of the field mice of the subgenus 
Microtuft. Farther south, where these mice occur sparingly or not at 
all, the cicognani series of weasels is replaced by the larger and more 
powerful longicauda-frcnatuH series. Where the ranges of the twO' 
overlap, as on the northern plains, the large weasel (P. longicanda) 
preys chiefiy on pocket gophers [Thomomys and Geomys) and ground 
squirrels {Spcrniopliilus franlUni and S. 13-lincatufi), while the smaller 
species {cicognani and rixosus) prey chiefly on mice. 


Similarly in the far Nortli, where the frozen tundras are inhabited by- 
lemmings as well as voles, two weasels are present: the tiny, narrow- 
skulled rixosus, which feeds mainly on mice, and the large, broad-skulled 
arcticus, which feeds chiefly on lemmings and rabbits. 

It seems clear, therefore, that the different types of weasels have been 
developed by adaptation to particular kinds of food. 

It is much to be regretted that sj)ecimens of the South American 
weasels are not available for study in connection with the North Amer- 
ican species. The only one I have seen is P. offinis Gray, which ranges 
from Costa Rica to northern South America. While differing specif- 
ically from frenat lis it clearly belongs to the same group. 

Except in winter, weasels are usually so difficult to procure in any- 
thing like satisfactory series that but few are available from most of 
the localities represented in collections. As a rule, the number is too 
small to afford reliable average measurements; hence the averages here 
given are subject to correction. 

The skull drawings in PI. I and those in the text (except figs. 10, 
11, 15, and IG) were made by Benjamin Mortimer. Those in Pis. II to 
V, inclusive, were drawn by Dr. James C. McOonnell under the super- 
visi(m of the author. About half of the skulls shown in the latter 
plates were used by Mr. Bangs in his paper already referred to. 

Except where the contrary is distinctly stated, all the measurements 
ill this paper were taken in the flesh by the collector. It is hardly 
necessary to add that all measurements are in millimeters. 

Genus PUTORIUS Cuvier, 1817. 

Key to subgenera (for American forms only) : 

Size large, about equaling tlie mink (Luh-eola); facial bar black; legs and feet 
abruptly darker than upper parts subgenus Putorius. 

Size medium or small, never more than lialf as large as the mink (Liitreola); 
facial bar white or absent; legs and feet concolor with or paler than upper 
parts subgenus Ictis. 

Subgenus PUTORIUS Cuvier, 1817. 

P«7on«s Cuvier: Rt-gne Animal, I, 147-149, 1817. 
Cynonijionax Coues : Fur-Bearing Animals, 99, 147-148, 1877. 

PUTORIUS NIGRIPES Aud. & Bach. Black-footed Ferret. 

(PI. I, figs. 1, la, lb.) 

1851. Putorius nUjrlpes Aud. & Bach. : Quadrupeds N. Am., Vol. II, pp. 297-299, pl. 

93, 1851. 
1877. Coues: Fur- Bearing Animals, 149-153, 1877. 

Type locality. — Plains of the Platte River, in Nebraska. 

GeograpMc range. — Great Plains, from western North Dakota and 
northern Montana to Texas ; not known west of eastern base of Rocky 

Characters. — Size of the mink; ears rather large; color buffy, with a 




(lark area in middle* of hack; fore and liind feet, end of tail, and baud 
across fa'ce (inelnding- eyes) black. 

Color. — Ground color pale yellowisli or buli'y above and below, 
clouded on top of head (and sometiiiies on neck also) by dark-tipped 
liairs; face crossed by a broad baiid of sooty black, which includes the 
eyes; feet, lower part of legs, terminal third of tail, and preputial 
region, sooty black; back, about midway between fore and hind legs, 
marked by a large patch of dark umber-brown, which fades insensibl}' 
into the buffy of surrounding parts; muzzle, lips, chin, a small spot 
over each eye, a narrow band behind black facial bar, and sides of 
head to and including ears, soiled wliite; anterioi- margin of ear near 
base clouded with dusky. 

Cranial characters. — Skull large and massive, very broad between 
orbits, and deeply constricted behind postorbital processes,' whicb are 
strongly develo])ed; zygomata strongly bowed outward; audital bulhe 
obliquely flattened on outer side; a jn'ominent bead over lachrymal 

Compared with our American weasels, the skull of l*ittorins nigripes 

may be told at a glance 
by its great size, the 
basilar length in adult 
males averaging about 
05 mm., and in females 
about 02 mm. Com])ared 
with P. crersmanni of 
s^ southern Siberia, it may 
be distinguished by the 
greater postmolar pro- 
duction of the palate, 
and by other minor cra- 
nial characters. From 
the common polecat of Europe {Tutor i no putorins) it differs in several 
important characters, as may be seen by reference to PI. I. In P. imto- 
rivs the postorbital region is very broad, the postmolar part of the 
palate exceedingly long, and the anterior part of the audital bulLne, very 

Remarl\s. — The black-footed ferret bears no resemblance whatever to 
any other American mammal, but is very closely related to the Sibe- 
rian Pntorins crersmanni. It differs from the latter in having much 
shorter and coarser fur, larger ears, and longer postmolar extension 
of the palate. 

In some specimens of Ptitorius oiifiripcs the ]>ale buffy of the under 
parts is clouded across the breast between the fore legs, suggesting the 
dark breast of P. eversmanni. The dark facial mask encircles the eyes 

'This coustrictioD deepens -witli age, as in all the Aveasels. It is verj'^ deep iu tlie 
slinll slio^vn in the accompanying text figure (fig. 1), which is that of an old indi- 
vidual; much less deep in the younger specimen shown on PL I, fig. 1. 

'Fm.l — I'liforiiis nigripps ^ ad. Trego Connty, Kans. 


(incliuling- the wliitisli suprnorbital spot) and dips slightly forMavd 
before passing- transversely across tlie face, so that its ])osterior border 
is in front of the plane of the outer angles of the eyes. Its anterior 
border sometimes extends forward almost to the nasal pad, but this is 
unusual. The black of the feet "reaches up and covers the fore ]eg to 
the elbow, except along- the outer side, and the hind leg- to near the 
knee, excei)t ])osteriorly. 

,}[casKr('m(')ifs.^ — Average of 3 males: Total length, 570; tail A^erte- 
br;c, 133; hind foot, (JO. Average of 2 females: Total length, 500; tail 
vertebra^, 1-0; hind foot, 55. 

Craiiidl nicasnrenioifs. — Average of 4 skulls of adult males: Basal 
length, 04; basilar length of I iensel, 02.5; zygomatic breadth, 43; mas- 
toid breadth, 37; breadth across postorbital processes, 22.5; iiiteror 
bital breadth, 18; breadth of constriction, 12.5; palatal length, 33; 
postpalatal length, 31.5. Average of 2 skulls of adult females: 
Basal length, G0.5; l)asi]ar length of Heusel, 58.5; zygomatic breadth, 
39; mastoid breadth, 34.5; breadth across postorbital processes, 20; 
interorbital breadth, 1G.5; breadth of ccnstriction, 12; palatal length, 
31; postpalatal length, 20. 

Subgenus ICTIS Kaup, 1829. 

Icth Kanp: Entwickeluiigs-Ciescliiclite mul Naturliches System der EuropJiiscben 

TLierwelt, ])p. 40-41, 1829. (Contaius only a single species, Mitsiela nil.'/arin.) 

ScLulze: Faunsp Saxonica>, Jlauimalia, p. 170, 1893. 
ArctogaU Kaup : Entwickcluugs-CJescliicbte und Naturliches System der Euroi)ai- 

sclien TLierwelt, p. 30, 1829. (Contains two species, cvmlnea and hoccamela.) 
firt/e Wagner: Sujiplement Sclireber's Saugtliiere, II, p. 234, 1841. (Contains four 

species, /iV'/u(fy(s, crmiiiea. hoccamela, and luthjaris.) 

The names Icti.'; and Arefof/alc were proposed simultaneously in the 
same publication. Each is accompanied by a diagnosis and included spe- 
cies. The two names, therefore, according to Canon 18 of the A. O. U. 
Code of i^omenclature, are e(|ually pertinent. In se(iuenc(; of pagiim- 
tion Arctogalc conies 10 pages ahead of letis. let is contaius a single 
species {rulg((ri.s = niralis Linn.), while ArctogaU' has two {erminea 
and hoccaDicla). The reasons for choosing Trtis instead of .1 rctogaJe are : 

(1) The type of Ictis is fixed beforehand, since it contained only a single 
species, while in Arctogale the type must be established arbitrarily; 

(2) Arctogale is now in current use for another genus of small carniv- 
ora;2 to transfer it to a different group would lead to much confusion, 
and would be a, great and seemingly unnecessary calamity. Hence, 
since there is no rule to the contrary, the better course seems to be to 
adopt Ictis and allow Arctogale to t\ill into synonymy. 

'The number of specimens of which reliable flesh measurements are available is 
too small to afford satisfactory averages. 

'•'Jrcfojra/ta'eters, 1864, a genus of Viverrida-; (Jray, Proc. Zool. Soc. London, 18()4, 
pp. 508, r,42-543 ; Blanford, Fauna P.ritish India, .Alanimalia, p. 114, 18S8; Flower and 
Lydekker, Introduction to Study of Mammals, p. 533. 1891; Lydekker, Royal Nat. 
Hist,,!, p. 401,1893-94. 


rurtliermore, Ictis has been already revived by Schulze (Faunae 
Saxonicjie, Mammalia, 170, 1893), thou.yh used by bim iu a much more 
comprebensive sense tban tbat originally intended.' 

List of North American IVeaiiels with type localities. 



Type locality. 


Northeastern North America (north of lat. 4P) 


Fori Franklin, Great Bear Lake. 

Skajiit Valley, Wasliington. 
Osier, Saskatchewan. 
Point Barrow, Alaska. 
Kafliak Lsland, Ala.ska. 




areticus kadiaccnsls 

Trout Lake, Mount Adams, "Washington. 
Tarpon Springs, Florida. 
Carlton House, Saskatchewan. 
Fort Snelling, Minn. 




longicauda spadix 

Fla'^stalf, Arizona. 

Black Hills, South Dakota. 

Southern California. 

Rogue Eiver Vallev, Oregon. 

Valley of Mexico. 
Pinabete, Chiapas, Mexico. 

frenatus leucoparia 



Patzcuaro, Michoacan, Mexico. 
Jico, Vera Cruz, Mexico. 
Colombia, South America. 

PUTORIUS CICOGNANI Bonap. Bonaparte's Weasel. 

(PI. II, figs. 3, 3ft, 4,4a.) 

1829. Mustela (Putoritis) vulgaris Richardson: Fauna Boreali-Americana, Mammalia, 
pp. 45-46, 1829. 

1838. Mustela cirognanii Bonaparte: Iconografla Fauna Italica, I, fasc. XXII, p. 4, 

1838; Charlesworth's Mag. Nat. Hist., II, p. 37, Jan., 1838. 

1839. Fatorins cicoguanii Ricbanlson : Zoology Beecliey's Voyage, p. 10*, 1839. 
1857. Baird : Mammals North America, pp. 161-163, 1857. 

1891. Mearns: Bull. Am. Mus. Nat. Hist., N. Y., Ill, p. 235, May, 1891. 

1896. Pidorius riehardsoni cicognani Bangs : Proc, Biol. Soc.AVash., X, pp. 18-21, Feb. 25, 

1877. Putoriiis vulgaris Cones: Fur- Bearing Animals, pp. 102-109, 1877. Merriam: 

Mammals Adirondacks, pp. 54-56, 1882 (habits) ; and most recent authors. 

Type locality. — Nortbeastern Nortb America. 

Geograpliic (UsirihuUon. — Boreal forest covered parts of North Amer- 
ica from New England and Labrador to coast of sontheastern Alaska 
(Jnneau, Wrangel, and Loring), and soutli in the Rocky Mountains to 
Colorado (Silverton). It occurs in the interior of British Columbia (at 
Sicamous), but in the Puget Sound region is replaced by a smaller and 

1 Schnlze included in Ictis the two European weasels, vulgaris and erminea, and 
also the mink, lutrcola, and polecat, imtoria. 



darker form, P. fitreatori. In the United States it is common in New 
England and New York, and in the forest-eovered parts of Minnesota. 
It probably oocnrs also in northern Michigan and Wisconsin. 

Gciirral characters. — Sixe small; tail slender and rather short; color 
of under parts covering- toes and inner sides of botli fore and hind feet;: 
color of npi)er ])arts never encroaching on belly, ])nt ending- along- a. 
straight line. 

Color. — Upper T)arts in ftummer pelage : uniform dark brown, hardly 
darker on head; end of tail blackish; no dark spot behind corners of 
mouth; under i)arts, usually including ui)per lip, white, more or less 
tinged with yellow. In winter pelage: i^ure white with a strong yellow- 
ish tinge on rump, tail, and under parts; end of tail black. 

Cranial characters. — Skull sraall.^ light, narrow, and elongated witlr- 
out marked postorbital processes, and only a slight postorbital constric- 
tion; zygomata narrow, and jiot bowed outward; brain case elongate 
and subcylindric; audital bulliB small, narrow, and siibcylindric, almost 
continuous anteriorly (except in old age) 
with the greatly inflated sipuimosals; 
palate narrow; the tooth rows more 
nearly parallel than in the other spe- 
cies; skull of female similar to that 
of male, but smaller. Contrasted with 
riehanhoniy the skull of cicognani is 
smaller, the audital bullae decidedly 
smaller, and the dentition lighter. In 
nearly every series of eii-ognani there are 
one or two old males whose skulls are 
abnormally large and closely resemble 
skulls of riehardsoni, except that the 
audital bulhe are always smaller. 

Measurements. — Average of 5 males from Ossipee, N. H. : Total 
length, 278; tail vertebne, SO; hind foot, 30.5. Average of 3 females: 
Total length, 230; tail vertebra?, 69; hind foot, 30.5. 

PUTORIITS CICOGNANI RICHARDSONI (Boiiap.). RichcariLsoii's Weasel. 

1829. Mnstela (_Putoriiis) erminea Ricliardson: Fauna Boreali-Amcricana, p]). 46-47, 
1829. (lu part: specimen from Fort Franklin, Great Bear Lake. Not M. 
erminea Linn.) 

1838. Musteta richarilsoiii Bonap. : Charles worth's Mag. Nat. Hist., Vol. XI, p. 38, 

1838. (l)aseil on Richardson's specimen from Great Bear T^ake). 

1839. Piiioriiis richard.'ioni U'igIi. : Zool. Beechey's Voyage of Blossom, Mannniilia, 10*, 

1896. Bangs: Proc. Biol. Soc. Washn., X, pp. 1-24, Feb. 2;-), 1896. (In part.) 

Type locality. — Fort Franklin, Great Bear Lake. 

Geographic (listrihut'ton. — Iludsoniau timber belt from Hudson Bay 
to interior of Alaska and British Columbia. 

General characters. — Similar to P. cicognani but larger; tail of 
medium length, its terminal third black. 


i aud 3. — P. cicognani cf ad. Elk 
Eiver, Minnesota. 


Color. — TTppor parts dull clioeolate brown, tliis color reacliiiig down 
on both fore and liind feet to base of toes; underparts whitish, more 
or less suffused witli yellowish, the pale color extending out in a very 
narrow aud sometimes interrujjted strip along inner side of hind feet 
to toes; tail concolor all around except at tip, which is black for about 
one-third the total length of tail. In n-intcr pelage: white all over 
except termiual third of tail, which is black; ruraj) and belly more or 
less tinged with yellowish. 

Cranial characters. — Skull long, narrow, and .subcylindric like that of 
cieognani, from which it differs chiefly in larger size, larger audita! 
bulhe, and heavier dentition. 

Remarls. — P. richardsoni, as pointed out by Mr.Bangs, is simply a more 
northern form of eieoguani, with which it intergrades completely. It 
inhabits the Hudsonian timber zone while cieognani inhabits the Cana- 
dian. On the north, where the timber ends and the tundra begins, the 
range of richardsoni meets that of arcficns. The two species differ 
widely in both cranial and external characters. The light subcylindric 
skulls of richardsoni J with the narrow frontals and appressed zygomata, 
require no comparison with the broad massive skulls of arcticus with 
their broadly flattened frontals and widely spreading zygomata. The 
external differences are almost as marked. In richardsoni the under- 
parts are nearly white or, at most, only tinged with pale yellowish; tlie 
color of the upjier parts covers both fore and hind feet, reaching the 
base of the toes; the tail is relatively long, coucolor except at the tip, 
which is black for about one third its length. In arcticus the under 
parts are deep yellow; the color of the upi)er parts stops short of tbe 
fore feet and reaches only halfway down the hind feet; the tail is short, 
yellow below on its basal half, and has a long, black pencil covering at 
least half its entire length.^ 

Measurements. — (From dry skin of male from Fort Simpson): Total 
length, 390; tail vertebra', 05; hind foot, 43 (probably 45). 

PUTOKHTS KICHARDSONI ALASCENSIS siibsp. nov. .Tiuipaii "Weasel. . 
(PI. II, figs. 2. 2a.) 

Type from Jmiean, Alaska. Xo. 74423, ^ ad., IT. S. National Museum, Dept. Agric. 
coll. Collected August 22, 1895, by Clark P. Streator. Original number 4806. 

General characters. — Similar in size and general appearance to P. 
richardsoni, but white tips of fore and hind feet more extensive and 
interorbital region very much broader. 

Color. — Upper parts dull chocolate brown, this color reaching down 
on fore legs to wrists and on hind legs to middle of iipper side of feet; 

1 It is not strange that Mr. Bangs failed to discriminate between arellcns and 
rii;harchoui. Tiie available material is scanty and mostly of poor quality, aud most 
of the skins had the skulls inside. Through the kindness of INIr. F. W. True, cura- 
tor of mauHuals in the United States National Museum, tbe skulls have been removed 
and placed at my disposal. 


tei'iniual third of tail black; uuder i)arts, iuchiding^ upper li]), fore feet, 
and distal half of hind feet, soiled white, tinged with yellowish. Winter 
pelage probably white. 

Cranial characters. — Skull similar to that of P. richardsoni, but very 
much broader between orbits and across muzzle; postorbital processes 
more strongly developed; constriction deeper. 

EemarlxS. — Mr. Streator obtained two males of this new weasel at 
Juneau in the latter part of August. He obtained also, at the same place 
and time, three females, which in color aud markings agree with the 
males, but are hardly half as large. Their skulls are as small as those 
of true cicognani, which they closely resemble. If they are the females 
of ulascensis, as seems probable, then this weasel exhibits as great 
sexual difference in size as P. noveuoracensls, in which respect it stands 
unique as a member of the cicognani group. The only alternate possi- 
bility is that cicognani and alascensis occur together at Juneau, and that 
of the 5 specimens collected there by Streator the 2 males are alascensis 
and the 3 females cicognani. 

Measurements. — Average of two males from Juneau, Alaska: Total 
length, .335; tail vertebrse, 95; hind foot, 48, Average of three females 
from same place: Total length, 270; tail vertebra;, 77; hind foot, 34. 

PUTORIUS STREATORI sp. uov. Puget Sound Weasel. 

(PI. II, figs. 5, 5(t, 6, 6a.) 

Type from Mouut Vernou, Skagit Valley, Washington. No. 76646, ^^ a<l., U. S. Nat. 
Mils., Dept. Agric. coll. Coll. Feb. 29, 1896, by D. R. Luckey. (Original number 3 ) 

Geographic (listribution. — Puget Souud and coast region of Washing- 
ton and Oregon; south at least to Yaquina Bay (Newport), Oregon. 
Confined to a narrow strip along the coast. 

General characters. — Similar to Putorius cicognani., but smaller and 
darker, with color of upper i)arts encroaching on belly. 

Color. — Upper i^arts, including upper lip and fore and hind feet, 
uniform dark chocolate brown, darkest on head, and encroaching far 
on belly aud throat (often meeting along middle of belly); terminal 
third of tail black; under parts narrowly and irregularly white, faintly 
tinged with yellowish. In winter pelage at low altitudes the color of 
the upper parts is paler (almost drab brown) and the toes may become 
white; at higher altitudes the whole animal changes to white, ^ except 
the end of the tail, which always remains black. 

Cranial characters. — Sku,ll of male similar to that of male cicognani, 
but smaller, slightly broader in terorbi tally, and with somewhat more 

'Mr. R. E. Darrell, of Port Moody, British Columbia, writes me : " I have discovered 
that, although the weasels do not change color down near salt water, they do chang'? to 
the white winter coat in the mountains." Specimens in the Department collection 
from Mount Adams, Washington, killed in February and March, are in the white 
winter pelage. The type and a female from the same locality (Mount VernoUj, 
Skagit Valley) are in the drab-brown wuiter pelage. 


prominent postorbital processes and smaller aiidital bulla', Sknll of 
female very mucli smaller and more delicate tliau that of male, 
resembling" female o£ cicognani, but snmller. 

Rniwrks. — Futorins streatori is a dark Pacific; Coast form of cicognani^ 
with which it may be found to intergrade. It differs conspicuously 
from cicogncmi in the color of the under parts, the dark chocolate brown 
of the back and sides encroaching far on the throat and usually meet- 
ing along the median line of the belly, thus reducing the white to a 
narrow and irregular strip, which expands on the anterior part of the 
throat, on the breast behind the fore legs, and immediately in front of 
the hind legs, and stops abruptly on the under surface of the thighs. 

Five winter specimens from Sumas, British Columbia, kindly loaned 
by ]\[r. Outram Bangs, point toward intergradation with eicognani. In 
three out of the five, the toes of both fore and hind feet are white, and 
the color of the ujiper jjarts is much paler than in summer pelage. 
Two of these specimens have the bellies broadly white, as in eicognani. 
They are also much larger than streatori. Specimens from Sicamous, 
in the interior of British Columbia, are fairly typical eicognani^ having 
the nnder parts broadly white; the upper lip, a strip along the inner 
border of the hind feet, and the toes of both fore and hind feet, while. 
Specimens from southeastern Alaska (Juneau, Wrangel, and Loriug) 
must also be referred to eicognani, and not streatori. 

Measurements. — Unfortunately, no flesh measurements are available 
from the type locality. Specimens from Trout Lake, near Mount Adams, 
Washington, are slightly smaller than the Mount Vernon specimens, 
and measure as follows: Average of two adult males: Total length, 
270; tail vertebne, 83; hind foot, 33. An adult female: Total length, 
210; tail vertebra', 51; hind foot, 24. 

PUTORIUS RIXOSUS Bangs. Bang's Weasel. 

(PI. II, tigs. 7, 7a.) 

1857. rutorius pusillus Baird: Mammals N. Am., pp. 159-161, 1857. (In part: speci- 
men from Pemhina.) 
1896. rutorius rixosus Bangs: Proc. Biol. Soc. Wash., Vol. X, pp. 21-22, Feb., 1896. 

Tyjw locality. — Osier, Saskatchewan, Canada. 

Geographic distribution, — Boreal America from Hudson Bay to coast 
of Alaska (St. Michaels); south to northern Minnesota (Pembina) and 
Montana (Sun River). 

General characters. — Smallest weasel known; tail short and without 
black til) ; only American weasel lacking the black tip. 

Color. — Summer pelage: Upper parts dark reddish brown; tip of tail 
not darker ; under parts white. In ivinter pelage: Pure white all over, 
including end of tail. 

Cranial charaeters. — Skull (of type specimen, 9 ad.. No. 642 Bangs' 
Coll.') very much smaller than the smallest female of any other known 

• I am inclebted to Mr. Bangs for the privilege of examining this specimen. Unfor- 
tunately, the hasioccipital is broken otf ; hence the basilar length is estimated. 


species (total length from occiput to front of preninxillic, 28.05 ^asal 
length, liG.ii; zygomatic breadth, 14; length of palate, 11; interorbital 
breadth, 5.5; breadth across postorbital processes, 7.5; length of aiidi- 
tal bnlla^, 9.5). The skull is a miniature of P. cicognani except that tlie 
postorbital processes are more i)romiuent, the braiu case more com- 
pressed, and there is a distinct sagittal ridge. 

MeaHuremenis. — Tjq^e specimen, female, measured in flesh: Total 
length, 150; tail vertebra^, 31; hind foot in dry skins, 20-22. 

PUTORIUS ARCTICUS sp. nov. Tuuclia Weasel. 
^ (PI. II, tigs. 1, 1«; PI. V, figs. 6, 6«.) 

Tijpc from Point Barrow, Alaska. No ^liiTn <? ^^- U- S. Nat. Mus. Collected July 
16, 1883, by John Murdoch. Original number, 1672. 

GeodrapMc distrihution. — Arctic coast and tundras. Specimens ex- 
amined from Anderson Kiver, Franklin Bay, old Fort Good Hope, lower 
Mackenzie River, Point Barrow, and St. Michaels. 

General characters. — Size large; ears small; tail short but with very 
long black pencil; underi)arts yellow (including underside of basal half 
of tail). 

Color — (Type specimen, male adult.) Upper parts, including upper 
lip, dark yellowish brown ; chin white ; under parts deej> ochraceous yel- 
low, broadly including inner and posterior sides of fore legs, whole of 
fore feet, distal half and inner side of hind feet, and under side of tail 
to or nearly to black tip; black tip very long, covering at least half of 
tail (including long terminal hairs); color of upper parts not encroach- 
ing on belly. In icinter 2iela(je, white all over except long black tip of 
tail; the white tinged with yellow posteriorly. 

Cranial characters. — Skull rather large, broad, and massive; frontal 
very broad interorbitally; muzzle broad and blunt; postorbital proc- 
esses moderately develoj^ed; postorbital constriction marked; zygo- 
mata strongly bowed outward; brain case subtriangular and rather 
short; audita! bulhe subcylindric; postglenoid space smaller than in 
richardsoni and hardly iuHated except in female. Contrasted with 
P. richardsoni, the skull of P. arcticus is somewhat larger, ]nuch broader, 
and more massive; braiu case subtriangular instead of subcylindric; 
zygomata bowed far outward instead of appressed; postorbital pro- 
cesses more prominent; i)ostorbital constriction much deeper; frontal 
much broader interorbitally; palate broader posteriorly; dentition 
heavier. Adult male skulls of P. arcticus resemble certain old males 
of washingtoni, but differ in much greater breadth of frontal between 
orbits, broader muzzle, and blunter jiostorbital processes. P. arcticus 
resembles true erminea of Sweden much more closely than it does any 
American species. 

Rcmarhs. — Putorius arcticus, which has been heretofore confounded 
with erminea or richardsoni, is one of the most strongly characterized 
species of the genus. It is a large animal with deep ochraceous yellow 


under i)arts aud a rather short tail which ends in a remarkably long 
black pencil. The skull differs from all other American weasels in the 
great breadth of the frontal region and the breadth aud bluntuess of 
the muzzle, in both of which respects it resembles true erminca. The 
only American species wliose skull approaches it at all is P. washhuf- 
toni, as mentioned above. In exterjuil characters the differences are 
too great to require comparison. 

It is interesting to find in this country an Arctic circumpolar weasel 
which, though S[)ecifically distinct, is strictly the American representa- 
tive of the Old World erminea. The ])attern of coloration, as described 
above (under color), is precisely as in enninea, but the tints differ 
materially. The upper pai'ts in erminca lack the golden brown of 
((rcticHs, and the under parts are very much paler aud of a different 
tint, being 'i)ale sulphur yellow instead of ochraceous. Moreover, 
arcilcuH lacks the whitish border to the ear which is present in erminea. 
In winter pelage the two seem to be indistinguishable except by cranial 

A small form of arcticns oc(;urs ou Kadiak Island, xVlaska. It has 
smaller aud narrower audital bulhc, less spreading zygomata, less 
divergent tooth rows, and decidedly shorter postmolar production of 
l)alate. It is probably wortLy of recognition as subspecies l((diacensis. 
An adult male (No. G52!)0) collected April 25, 1804, by B. J. Bretherton, 
measured in the flesh: Total length, 318; tail vertebr;i', 80; hind foot, 
41. It is in the white winter i)elage, just beginning to change, aud the 
terminal half of the tail is black. 

MeaHnrcmentti. — From dry skin of tyi)e, male adult. Point Barrow, 
Alaska: Total leugth, 380; tail vertebrte, 75; pencil, 55; hind foot, 48 
(at least 50 in the flesh). 


(PI. IV, figs. 1, la, 2, 2a; PI. V, tigs. 3,3a. 

1810. J'lttorius iioveboracensisDe Kay: Catal. Mammalia New York, p. 18, 1810 {nomen 

nudum); Zoology of New York, Mammalia, p. 36, 1842. 
1840. Emmons: Rept. Quadrupeds Massachusetts, p. 45, 1840. 
1857. Baird : Mammals N. Am., pp. 166-169, 1857. 
1896. Bangs: Proc. Biol. Soc. Wa8li.,X, pp. 13-16, Feb. 25, 1896. 
1877. Futorlas ( Gale) erminea Cones : Fur-Bearing Animals, pp. 109-136 ( in part), 1877. 
Futo7-iHs erminca Thompson, Aud. & Bach, (part), Allen, Merriam, aud most recent 

Type locality. — New York State. 

Geographic distribution. — Eastern United States from southern Maine 
to North Carolina, and west to Illinois, 

General characters. — Male large; female small; tail long aud busby, 
much longer than in cicoynani, but shorter than in lonyicaiula; the 
black terminal part longer than in any other species except articus, 
covering oue-third to one-half the tail and measuriug 50 to 75 mm. 
Animal turns white in winter in northern part of range. Extraordinary 
sexual difference in size aud crauial characters. 



Color. — Smnmer peUuiv: Uiiper parts, including fore and liiud feet 
and anal region, and often encroaching irregularly on belly, ricli dark 
chocolate brown, sometimes suggesting sealbrown ; under]>arts (usually 
including ujtper lip) white, more or less washed with yellowish; no 
yellow on under side of tail or on hind feet, the color of under parts 
stopping short of ankle. Wintir pelage: In southern jjart of range 
similar to summer pelage, but upper parts paler, nearly drab brown. 
Northern specimens white all over except terminal third of tail, which 

is jet black; throat, belly, posterior 
half of back and tail always suilused 
Avith yellowish. 

Cranial characters. — Skull of male 
large, heavy, and elongate; sagittal 
ridge present in adults; postorbital 
l)rocesses and constriction mod- 
erately developed; zygomata not 
hoired oittirard; audital bulla' rather 
narrowly oval, usually rounded an- 
teriorly as well as posteriorly. Skull of female very small, light, and 
narrow, Avith brain case elongate and subcylindric, much as in cicognani; 
audital bulhe sjuall, narrow, and not rising abruptly anteriorly from 
intlated squamosals, which latter are elongated and strongly inflated as 
in cfcognani. Skulls of males may be distinguished from those of male 
longicauda by shorter postorbital processes, less nmrked postorbital 
constriction, less triangular brain case, lower sagittal ridge, very much 
narrower zygomata, which are not bowed outicard, narrower palate, and 
narrower audital bulhe, which are more rounded anteriorly. The resem- 
blance to F. icashingtoni is very much closer, but male skulls oi noreho- 

FlG. 4. — Putorius nuvcb'iracoisi'; cT ;id, 
daulis, New York. 


5 and li. — I'uturins tiiireboraceimis. Adirondacks, Kew York. 

racensiH may be distinguished by larger size and much larger audital 
bnllffi. The female skull, owing to the inflation of its squamosals 
inferiorly, needs no comparison with either washingtoni or longicauda, 
but is with difllculty separated from cicognanl in regions where the two 
species overlap. The postorbital processes are longer and the car- 
nassial and sectorial teeth larger in the females of norehoraceHsis than 
in cicognanl from the same localities. 

Bemarls. — Futorins uorehoraccnsis may usually be distinguished from 
P. cicognanl l)y larger size and also by the longer and more bushy tail, 
16932— No. 11 2 


aiul greater length of the l)lack terminal part. Females of nonhora-, however, sometimes resemble males of cicognanl rather closely. 
They may be distinguished not only by the greater length of the tail 
but also, if in summer pelage, by the absence of yellow from the under 
side of the tail and inner sides of the hind feet, which parts in cicognani 
usually show more or less yellow. 

Measurements. — Average of 10 males: Total length, 407; tail ver- 
tebra>, 140; hind foot, 47. Average of 10 females: Total length, 324; 
tail vertebra', 108; hind foot, 34.5. 

PUTOKIUS WASHINGTON! sp. iiov. Wushiugton Wetisel. 

(PI. IV, figs. 3, 3a, 4,4a.) 

Tyi)e from Trout Lake, base of Mouut Adams, State of Wasliingtou. No. 7(5022, J^ 
ad., U. S. Nat. Miis., Dept. Agriculture collectiou. Collected December 15, 1895, by 
D. N. Kaegi. 

General characters. — Similar to P. novehoracensis in size and general 
appearance, but with longer tail and shorter black tix). Female very 
much smaller than male, as in novehoracensis. 

Color. — Color in summer pelage unknown (probably dark chocolate 
brown). There are two winter pelages, probably dependent on alti- 
tude. In drah winter pelage: Upper parts uniform drab brown; end 
of tail black; under parts white, more or less suffused with pale yel- 
lowish. The color of the upper x)arts encroaches on the sides of the 
belly as in novehoracensis, and a brown spot is present behind the cor- 
ners of the mouth, which may or may not be confluent with the brown 
of the cheeks. In the type and two other specimens the hind legs and 
feet are the same color as the upper parts except that the toes are 
tipped with whitish and the tips of the fore feet are white. In another 
specimen, collected January 22, the white is more extensive, covering 
all of the fore feet and about half of the hind feet. In summer pelage 
the legs and feet are doubtless the same color as the upper parts, the 
white of the belly stopping high up on the thighs. In white wintev 
l^elage: White all over except black tip of tail; tail, rump, and belly 
strongly suffused with yellow. In one specimen (No. 76004, male, 
February 7, 1890) the yellow reaches forward over the back nearly to 
the shoulders; in another (No, 76588, male, February 4, 1896) the whole 
back is white. 

Cranial characters. — The skulls of the two sexes differ greatly: that 
of'the male resembles novehoracensis closely iu size and general char- 
acters, but differs in having the audital bulla- much shorter and the 
X)ostorbital processes less strongly developed. Thoi^ostorbital constric- 
tion is equally marked. The skull of the female is very much smaller 
than that of the male, averaging about 38 mm. in length, while the 
male averages 45 mm. Contrasted with the female of novehoracensis 
the brain case is broader»posteriorly and less cylindric. The audital 
bulhe are more sharply separated from the squamosal inflation and the 
latter is only slightly marked, not reaching tJie plane of the bullie. The 


resembliiiice therefore to P. cicognani is much less marked in the female 
ica.shitujtoiii than in the female novehoracensin. 

Eemarls. — This new species is represented in the collection by 14: 
skulls and 6 skins, of which the greater number are males. The female 
is darker than the males, and the top of the head is darker anteriorly 
than the rest of the upper parts, while in the males it is concolor with 
the back. These differences are probably seasonal, the female not 
having comi)leted the change from summer to winter pelage, though 
collected December 11. All are from the Mount Adams region. 

MeasnremenU. — The skins, which are well made, afford the following 
approximate measurements: Male, total length, 240; tail vertebra', 155; 
hind foot, 44. Female, total length, 300 ; tail vertebra?, 120 ; hind foot, 37. 

PUTORIUS PENINSULA Rhoads. Florida Weasel. 

(PI . IV, figs. 5, 5a; PI. V, tig. 5.) 

rutorius ptninsuhv Rhoads: Proc. Acad. Nat. Sci. Phila., June 1894, 152-155. 
Bangs: Proc. Biol. .Soc. Wash., X, pp. 10-13, Feb. 25, 1896. 

Type /oca^i^j/.—' Hudsons,' 14 miles north of Tarpon Sjmngs, Fla. 

Geographic distribution. — Peninsula of Florida; limits of range 

General characters. — Size rather large, about equaling male of Puto- 
rius noveboracensis ; skull similar to that of longicanda^ but with very 
large audital bulla*. 

Color. — Upper parts dnll chocolate brown, darkest on head; upper 
li]) and chin whitish; rest of under i)arts, including fore feet and toes 
of hind feet, yellowish; a brown spot behind corners of mouth ; a small 
tuft of white hairs under anterior root of ear. The color of the under 
parts covers the belly broadly and is not encroached ui^on by the color 
of the upper jyarts. Irregular and inconstant white markings are some- 
times present between and behind the eyes. 

Cranial characters. — Skull rather massive, resembling that of longi- 
canda, hwtvfith higher sagittal crest; less spreading zygomata; narrower, 
higher, and more swollen audital bulhe, and less prominent postorbital 
l)rocesses. Contrasted with P. norehoracensis the postorbital constric- 
tion is deeper, the l)rain case higher and moresubtriangular, the audital 
bnlla; higher and more swollen, the upper carnassial tooth decidedly 
larger, and the molar smaller. The upi)er molar is peculiar : It is short, 
hardly expanded at either end, and implanted at right angles to the 
premolar series. 

Measurements. — An adult female from Tarpon Springs, Fla. : Total 
length, 374; tail vertebrje, 127; hind foot, 44.5. 

PUTORIUS LONGICAUDA Bonaparte. Long-tailed Weasel. 
(PI. Ill, figs. 3, 3a, 4, 4a; PI. V, figs. 1, la.) 

1829. Musfehi (FiitoriHS) erminea Kichardson: Fauna Boreali-Americaua, pp. 46-47, 

1829 (in i)ait: Spocinien from Carlton House). 
1838. Miislehi lonyicauda Bonaparte: Charlesworth's Magazine Nat. Hist. N. S., 

II, p. 37-38, 1838 (based on Richardson's long-tailed variety of erminea from 

Carlton House). 



[Xo. n. 


-Puturius longiraudu. 
S. Dak. 

Fort Sissetou, 

1839. Putorius loiigicauda Rich. : Zool. Beecbey's Voyage of Blossom, p. 10," 18"0. 

1857. Baird: Mammals N. Am., pp. 169-171, 1857. 

1877. Cones: Fur- Bearing Animals, pp. 136-142, 1877. 

1896. Bangs: Proc. Biol. Soc. Wash., X, pp. 7-8, Feb. 25, 1896. 

Type locality. — Carlton Hoase, on Noitli Saskatcliewan River, 

Geognqjhic (lutribnUon. — Great Plains from Kansas nortli\vai<l. 
General cliaracters. — Size large (adult males averaging al)out 4.">() mm. 

in total length) ; tail veiy long (ver- 
tebra* 155 mm. or more in males), 
its bla(-k ti]) ratlier short; under 
l)arts always strongly yellowish or 

Color. — Upper parts pale yel- 
lowish brown, or pale raw-umber 
brown, becoming darker on head; 
terminal part of tail black; chin 
and upper lip all the way round 
white; rest of under parts varying 
from strong buff'y yellow to ochraceous orange, the color extending from 
throat jjosteriorly, including upper side of fore feet, inner side of hind 
feet, and upiier side of hind toes; under side of tail more or less suffused 
with yellowish; soles of hind feet brownish. In worn summer pelage 
the color of upper parts is decidedly paler, and in some old specimens 
the upper and lower surfaces are not sharply differentiated. The 
orange tinge of the under 
parts is strongest on the 

Cran ia I c h a r a cter ,s . — 
Skull large, broad, and 
massive, with well-devel- 
oped postorbital proc- 
esses, strongly marked 
postorbital constriction, 
and a moderate sagittal 
crest; zygomata bowed 
strongly outward; brain 
case subtriangular as seen 
from above ; audital bulla; 
rather broad and subrect- 
angular; palate broad; 
dentition heavy; audital bulla- anteriorly rising abrui)tly from s((ua- 
mosal, which is not inflated in either sex; skull of female similar to 
male, but smaller, and with only a slight sagittal ridge. Contrasted 
with male skulls of novehoracensh and tcasJiingfoni, the male of lotif/i- 
cauda is broader and relatively shorter, with more spreading zygomatic 
arches, longer postorbital processes, deeper postorbital constriction, 

Figs. 8 and 9.—/'. Inmiicaiifla rf ad. Fort Sisseton, S. Dak. 



1111(1 imicli broader and more rectangular audita! bulliv^, wbicli as a rule 
are broadly truncate iustead of narrowly rounded anteriorly. 

Mt'dsnrements. — Average of 4 males from jjlaius of Saskatcbewan aud 
Alberta : Total lengtb, 450 ; tail vertebne, 1 65 : bind foot, 51. Average 
of 3 females: Total lengtb, o87; tail vertebr*, 144: bind foot, 44. 

J'ulurius loiniiciuida ■'<pudix Ban.irs: Proc. Piol. Soc. Wash., X, pp. 8-9, Feb. 25, 1896. 

Ty]}e locaJitij. — Fort Snelling, near Minneapolis, Minn. 

Geographic di.stribntio)i. — Edge of timber belt in Minnesota, along 
boundary between Transition and Boreal zones. 

General cliaracters. — Similar to P. lonr/icauda, but mucb darker. 

Color. — Swrnner pelage : Upper parts chocolate browu, darkest on tbe 
bead, but paler tlian in nove- 
horacevsis ; cbin and upi)er lip 
whitish all round; rest of under 
parts, including upper surfaces 
of fore feet and toes of hind 
feet, butfy yellow ; terminal part 
of tail black. Winter pelage: 
Snow-white everywhere except 
bbick tip of tail and a yellow- 
ish suffusion on rest of tail, and 
sometimes also on under side of 
bind i'i^et. 

Cranial charaeters. — As in P. 

Measurements.^ — Average of G 
males from Fort Snelling, iMinn. : Total length, 460; tail vertebrae, 166.5; 
liiiid foot, 54.5. Average of 3 females: Total lengtb, 356; tail verte 
bra-, 132; hind foot, 43.5. 

PUTORIUS SATURATUS .sp. uov. Cascade Mountain Weasel. 

Tjipe from Siskiyou, near soutlieru boundary of Oregon (altitude, about 4,000 feet). 
No. 65930, cT ad., U. S. Nat. Mas., Department of Agricultnrc colli-ctiou. CoUei'ted 
.June 6, 1894, by Clark P. Streator. Orig. No. 3905. 

General charaeters. — Similar to P. arizonensis, but larger and darker, 
with belly more ocliraceous, and with distinct spots behind the (!orners 
of the mouth. 

Color. — Color of upiier jiarts in summer pelage (June) dark raw 
umber brown, becoming much darker on the top of the head and nose; 
terminal part of tail black; a brown spot at corner of mouth which 
may be confluent with brown of cheeks ; color of upper parts extending 
over outer side of forearm to wrist, and over hind foot to toes; chin 

Fjgp. lu aiul 11. 

■ Putorius I. spaiiix ? ad. Elk Kiver, 

'These measnrenieuts were taken iu the liesh by Dr. E. A. Mearns, to whom I am 
indebted for them. 


white; rest of uiuler parts ocliraceons or orange yellow, including the 
fore feet, and reaching narrowly do\A'n the under side of hind leg to 
ankle, whence it may or may not extend in a nariow line along inner 
side of foot to toes; under side of tail more or less suffused with goldeu 
chestnut; anal region chestnut brown; in «'orn pelage the colors are 
everywhere much paler. 

Cranial characters. — Skull similar to tliat of P. arizonoisi.s but with 
postorbital processes broader at base and less peg like. 

RemarTcs. — This handsome weasel rei)laees lowjicauda on the Cascade 
and Siskiyou mountains of Oregon and Washington, reaching a short 
distance into British Columbia. The only specimens examined have 
come from Siskiyou, Oregon, and Chilliwack, British Columbia (the 
latter, No. 3553, collection of E. A. and O. Bangs). 

MeasnremenU. — Average of 2 males from Siskiyou Mountains, Ore- 
gon: Total length, 423; tail vertebrae, 164; hind foot, 48. 

PUTORIUS ARIZONENSIS Mearns. Mountain Weasel. 

rutoiius arisonensis Mearns: Bull. American Miiseniu Nat. Hist., Vol. Ill, No. 2, pp. 

234-235, May, 1891. 
Fiitorius loxgicauda Merriam : Mamnjals of Idaho, N. Am. Fauna, No. 5, pp. 83-84, Aug. 

1891 (from mountains of Idaho). 

Type locality. — San Francisco forest, Arizona (a few miles south of 

Geoyraphic diHribution. — Broadly, the Sierra Kevada and Rocky 

Mountain systems, reaching British 
Columbia in the Itocky Mountain re- 
gion, but not known north of the Sis- 
kiyou Mountains in the Sierra-Cascade 

General characters. — Similar to Pnto- 
rius longicauda in color and markings, 

n.j. 12,-P. arizunensig d ad. Boulder |j„(- much Smaller in sizC. 

Color. — Upper parts from occiput to 
black tip of tail, raw umber brown; head decidedly darker; end of tail 
black; chin and upper lip all round white; rest of under parts includ- 
ing upi^er surfaces of fore feet and inner half of hind feet and ujjper 
surfaces of hind toes ochrace<ms or ochraceous yellow, varying in tint. 

Cranial characters. — Skull similar to tliat of lonyicauda but decidedly 
smaller and less triangular; narrower across mastoids and more bulg- 
ing in parietal s. 

Eemarls. — Putorins arizonensis is a mountain form of longicauda^ 
wliich it closely resembles except in size. The type specimen, collected 
by Dr. Mearns on the pine plateau of Arizona a few miles south of 
Flagstaff, is an immature female and is of unusually small size. A 
male obtained by him near the same place is of the normal size, as is 
another male in the Department collection from Springerville, Ariz., 



collected by E. W. Nelson. Specimens from the iiortbern Eocky 
Mountain region (St. Mary Lake, Montana, and Salmon River and 
Palisimeroi Mountains, Idaho) dil'fer in color from the typical animal 
from Arizona and Colorado, and agree with aUeni from the Black Hills 
in having the upper parts strongly sntiused with golden brown, the 
yellow of the under parts yellow^ rather than ochraceous, and the under 
side of the tail strongly yellow on the basal half or two-thirds. The 
skulls, however, lack the tiattened audital bulhe of alleni. Specimens 
from the Sierra Nevada in California are hardly distinguishable from 
the Kocky Mountain animal. The only apparent external differences 
are that the yellow of the under jjarts reaches uj) farther under the 
chin, the white of the upper lip is less extensive, and the under side of 
the tail is more suffused with yellowish. But none of these characters is 
constant. In one specimen from Donner, Calif. (No. 2650, female, Mer- 
riam Coll.), even the white upper lip is as marked as in Eocky Mountain 
specimens; it reaches all the 
way round, fills the space under 
the nasal pad to the nostrils, 
and broadens strongly under 
the eyes. In cranial charac- 
ters also the differences are 
slight and inconstant. The 
jjostorbital processes are longer 
and more slender, often becom- 
ing peg like in old males. The 
audital bulhe average smaller 
and more convex anteriorly, 
and in the female are decidedly 
narrower and more subcylin- 
dric. But in an adult fenmle 
from Fort Klamath, Greg., the bulhe are nearly as broad as in Rocky 
Mountain females. The three female skulls I have seen of the Sierra 
form are decidedly smaller than females from the Eocky Mountains, 

The Sierra specimens show a strong tendency to grade into, or at 
least toward xantlwgenys. In nearly half the specimens examined white 
hairs are present between the eyes, and in several they are sufidciently 
numerous to form a conspicuous white spot, though the spot is not 
large and rectangular as in true xanthogenys. The white cheek spots I 
have not seen in Sierra specimens, but the brown spots behind the cor- 
ners of the mouth are sometimes present (as in No. 30055, male, from 
Upper Cottonwood Meadows, near Mount Whitney, Calif.). 

A specimen from St. George, Utah, an old female, differs in some 
respects from typical arizonensis. The skull is small and relatively 
short, and the shortening is mainly in the palate and rostral part, which 
measures 2 mm. less than the average of adult females of arizonensiH of 

Figs. 13 and 14. — P. arizonensis cT ad. 

Boulder County, 


the same size. Moreovei', tlie ])ostorbital ]>rocesses are longer and more 
slender than in any feniahvof arizoiwusi.s 1 have examined from either 
the Rocky ]\rountain or Sierra systems. Externally the St. (leorge 
specimen diflers from typical ariz<>ne)i.sis iu the following })articulars: 
Yellow of nnderparts more strongly tinged with ochraceous; wliiteof 
npi)er lip narrow and not reaching aronnd anteriorly; brown of npi^er 
X)arts reaching down on outer side of arm to wrist; a small bi^»wu spot 
bearing two bristles just behind each corner of mouth. In this respect, 
and this only, it resembles xanthoffcnys ; there is no trace of white on 
the cheeks or between the eyes. 

Meusnrements. — Average of 5 nudes from the Rocky MountaiDs: 
Total length, 385; tail vertebne, 144; hind foot, 44.5. Average of 4 
females: Total length, 358; tail vertebra^, 130; hind foot, 40. 

PUTORIUS ALLENI sp. nov. T.lack ] fills Weasel. 

Type fi'om Custer, Black Hills, Soutli Dakota. No. ;}f3ft, <? ad., Merriain collection. 
Collecteil July 12, 1888, hj Vernon Bailey. Original No. 90. 

Geogra'phiv disfnhiition. — Black Hills, South Dakota. 

Characters. — Similar to i*. arizonensis in size and general characters, 
but upper parts nu)re suffused with yellowish and audital bulhe Hatter. 

Color. — Upper parts from occi])ut to black tip of tail golden or yel- 
lowish-brown, in some lights with an olivaceous tinge; head dark 
brown, without yellowish tinge; upper lip and chin white; rest of 
nnderparts, including inner sides of legs, whole of fore feet, toes of 
hind feet and under side of basal part of tail, intense buffy yellow. 

Cranial cJiaracters. — Skull similar to that of arizonensis, but audital 
bulla^ much flatter and somewhat smaller; brain case slightly flatter 
and bulging laterally immediately behind constriction; frontal some- 
what broader interorbitally ; skull as a whole shorter. The skull of an 
old female (No. 7441, Am. Mus. JSTat. Hist.) is much smaller than the 
male, and the audital bulla? are narrow and not flattened. In both 
sexes the postorl)ital processes are strongly develoj^ed. 

Roitarls. — Putorius aUeni is an isolated and only slightly differen- 
tiated form of F. arizoncnsis, from which it is completely cut off' geo- 
gra])hically. It is surrounded on all sides by the large weasel of the 
plains, P. Jnngicanda. In worn summer pelage the color differences 
that distinguish it from arizone».sis are not apparent. 

I take ])leasure in naming the species in honor of Dr. J. A. Allen, 
of the American IMuseum of Natural History, New York, who has 
recently published an important paper on the mammals of the Blaci< 
Hills, and to whom I am indebted for the loan of three additional 

Measurements (of type specimen, male adult). — Total length, 372; tail 
Aertebriie, 137; hind foot, 44. 


PUTOKIUS XANTHOCtENYS ((iray). California Wca.s.l. 

1843. Musiela jioiihotjoiys Gray : Annals and Magazine Nat. Hist., XI, j)]!. 118, 1813. 
1857. Putorius xanthogniys Baird: Mannnals N. Am., pp. 17(5-177, 1857. 
1877. Fuforiiis (Gale) hi'asiliensix frenatiis Cones: Fur-Bearint;' Animals, ])]>. lJi!-146, 
1877 (in part). 

Type loealify. — ►Soiitlirrn ( 'alifornin, inobably vicinity of San Diego. 

Geographic distrihiitton. — Sonoran and Tinnsition iannas of ( -alifor- 
iiia, on both sides of the Sierra ISTevada. 

(ieneral characters. — Size medium; tail long'; face conspicuously 
marked with whitish, but vest of head not black; under i)arts 

Color. — Upper jiarts from back of head to terminal i)art of tail in 
summer pehigc raw-umber brown, tinged with golden: in n-i liter pelaije., 
drab brown, without yellowish suffusion : head always darker, becom- 
ing dusky over nose; a large rectangular s[)ot between ej'es, and a 
broad oblique band between eye and eir, whitish; end of tail black; 
a brown spot behind c orners of mouth ; chin white ; rest of under parts, 
iiiclnding- fore feet all round and inner side and toes of hind feet, vary- 
ing from l)uliy ochraceous to ochraceous orange. In some specimens 
the ochraceous covers the greater part of the hind feet as w^ell as the 

Cranial characters. — Skull of the longicauda type and practically 
indistinguishable in size and characters from /'. arizonensis; skull as a 
whole short and broad ; zygomata bowed outward; postorbital processes 
strongly developed; sagittal ridge distinct; andital bulhe moderate, 
usually truncate anteriorly; skull of female similar to that of male, 
but smaller. 

Remarls. — Putorias xanthogcnys inhabits the San Joaquin and Owens 
valleys and the t\ hole of southern California except the liigiier moun- 
tains. In ascending' the mountains it gradually loses the facial mark- 
ings and seems to grade into P. arizonensis^ the weasel o,f the mountain 

Measurements. — Average of 7 males from southern California: Total 
length, 402; tail vertebra', 150; hind foot, 43.5. Average of 3 fenuiles: 
Total length, 3G8; tail vertebras 135; hind foot, 40.5. 


Tijpe from Grants Pass, Rogue River Valley, Oregon. No. f|"is, 9 ad., U. S. Nat. Mns., 
Dept. Agric. Coll. Collected December 19, 1891, by Clark P. Streator. Original 
number 1404. 

(leof/raphic distribution. — liogue Iviver Valley, Oregon; limits of 
range unknown. 

(ieneral characters. — Similar to F. xanthogenys but decidedly larger, 
darker m color, and with face markings much restricted. 

Color. — LTpi)er parts m winter pelage pale chocolate brown, slightly 
darker on head; a small and ill-delined ])atch between eyes, and a imr- 


row veriical bar between eye and ear, -white; throat white; rest of 
under parts, including fore feet and inner sid(^s and distal half of hind 
leet, i)ale yellowish; terminal one-lifth oi' tail black; rest of tail above 
and below concolor with back and without the yellowish tinge which 
is characteristic of xanthogcnys. 

Cranial characters. — Skull similar to that of .rantliogriii/s but larger 
and decidedly broader. The slvull of the type, an adnlt female, com- 
pared with skulls of xantliogenys of the same sex and age I'roni south- 
ern California, differs in the following particulars: Skull everywhere 
broader; muzzle, palate, interorbital breadth and constriction very 
much broader; zygomata more si^readiug. 

3feasuremcnts. — Type specimen, female adult: Total length, 41L*; tail 
vertebra^, 155; hind foot, 44. ,■, 

PUTOEIUS FEENATUS (LicliteBsteiu). Bridled Woasel. 
(PL III, tigs. 1, la, lb, 2.) 

1813. Mustela IjraslUensiti Sevastianoff : Mem. Acad. Imp. Sci. St. Petersburg, IV, 
356-363, Table iv, 1813. (Name ou plate only; diagnosis in text.) Preoc- 
cupied by Mustela ij-asiUensis [an otter] Gmeliu, 1788. 

1832. Mustela frenaia Liclitenstein : Darstellung neuer oder wenig bekanuter Sau- 
gethiere, PI. XLII and corresjionding text (unpaged), 1832. 

18.57. rutorius frenatus Baird: Mammals N. Am., 173-176, 1857. 

Tyj)e locality. — Valley of Mexico, near City of Mexico. 

General characters. — Size large; tail long; its black tip relatively 
short; head black, with conspicuous white markings. 

Color. — Top of head blackish, interrupted between eye and ear by a 
broad, whitish band, which is nearly confluent with a x)atch of same 
color between the eyes; rest of upper parts brown; a dark spot behind 
corners of mouth; chin and throat whitish; rest of under parts ochra- 
ceous yellow; forefeet to or above wrists whitish or jjale bufly yelloAV- 
ish, continuous with and shading into ochraceous of under parts; color- 
of under parts extending down on inner side of hind legs and feet to 
toes, which are whitish or yellowish white. 

Cranial char<tcters. — Skull large and massive, with strongly devel- 
oped postorbital processes, deep postorbital constriction, marked sagit- 
tal crest, and peculiar audital bulhe, which are obliquely truncated 
anteriorily (the inner side reaching farthest forward) and abruptly 
highest on inner side, falling away suddenly on outer side so as to 
form a rounded ridge along the inner side of the longitudinal axis of 
the bulla. The skull oi frenatus resembles that of longicaucla, but is 
considerably larger, and differs in the form of the audital bulla* just 
described, and also in the extent of the postglenoid space, which is 
much larger than in longicauda. The dentition is heavy and the 
upper carnassial tooth relatively shorter than in longicauda. The 
ramus of the under jaw is much more convex interiorly. 

Jiemarl's. — Liclitenstein, in his original (lescrii)tion oY j\h(stelaj'rcnata, 
states that the tail is about one-third longer than that ol' the European 


weasel {erminea) ; that only its extreme tip is black ; that tlieliead, ears, 
aD(l crown are black, this (loloring' f^idiiiij into the reddish brown of the 
upper iKirts on (he back of the head behind the ears; that the facial 
markings, throat, and breast are white; the remainder of the under 
parts ocher yellow. The white spot between the eyes is described as 
heartshaped, and in the colored plate it is shown to be nearly, but not 
quite, continent with the white i^atc^h between the eye and ear. Tlie 
colors in the plate are not good, as the whole under parts are white 
instead of ocher yellow, and the black tip of the tail is not shown. The 
specimen seems to have been in worn pelage. Liclitenstein had two 
specimens, both collected by Depi)e near the City of Mexico. 

Fortunately, the Department collection contains two specimens col- 
lected by E. W. Xelson at Tlalpam, in the Yalley of Mexico, which may 
be considered topotyi)es of frcnatus, for they not only came from the 
same locality as Lichten stein's types, but also agree essentially in every 
detail with his excellent description. The only points in Avhicli the 
description fails to agree absolutely with the specimens is that in the 
hitter the white of the throat is less x)ure and the black tip of the tail 
perhaps a tritic more extensive than one would infer from the descrip- 
tion; but the throat is white in contrast with the strongly ochraceous 
yellow of the rest of the under parts, and a si)ecimen in the United 
States National Museum from the City of Mexico (No, lOGO, 9 ad., 
J. Potts) has both throat and breast white, as in the original description. 

The statement that only the extreme tip of the tail is black was made 
in comparison with the European weasel {erminea), in which nearly half 
of the tail is black. Hence the description agrees entirely with the 
S])ecimens in hand. One point not mentioned in the description is 
shown in the plate, namely, that the hind feet and toes are in large 
part whitish or yellowish white. The quantity of white is variable. 
In a young male from Tlalpam (No. 508U7) it is restricted to the inner 
side of the foot, hardly reaching the toes, while in an adult male from 
the same locality (No. 50826) it includes the toes. The whitish sjiot 
between the eyes is also variable, both in form and extent. Liclitenstein 
described it as lieart-sha]>ed, and his figure shows that it is narrow 
where it approaches closest to the stripe between the eye and ear, with 
which it is nearly, but not quite, contluent. This is precisely its coii- 
■ dition m the adult male from Tlalpam, which may be considered a 
duplicate type of the species. In this specimen the median white S])ot 
is almost divided by the dark color of the forehead, which pushes down 
between the eyes, so that the whitish spot might be described as a 
narrow stripe over each eye, the two becoming confluent below. In 
the young specimen the white spot is subrcctangular and not divided 
by tlie black of the forehead. 

Note on Putorivs hrasiliejisis. — In 1813 a Ilussian naturalist, Sevas- 
tiauoff, gave the name ^MuHteJa bra.silien.sis' to a weasel brought to 
St. Petersburg by Capt. A. J. Krusensteru oji his return from a voyage 


arouud the world. The aiiiuuil Avas said to liave come from Brazil, but 
110 definite locality was ijiveii. In the iininerous ])nl)licatioiis that have 
since api)eared relating to the mammals of Brazil and adjacent terri- 
tory, no weasels are mentioned as inhabiting that country, and. the 
species described from the mountains to the westward differ so widely 
from Sevastianoflf's hrasilien.sis that it is almost certain his animal did 
not come from Brazil, The original description (including measure- 
ments) agrees in every respect with P. frenaivH of Lichtenstien from 
the Valley of Mexico, indicating that tlie two animals are identical. 
On this assumption the well-known and appropriate name frenafus 
would have to fall before the earlier and inappropriate ^hrasilie)isu.^ 
Fortunately, however, Sevastianoff placed his animal in the genus 
Mustela, and the name ilf».S'^e/rt hrasiliotsis is preoccupied by Gmeliu 
for a South American otter. (Syst. ISTat., ed. 13, ]). 93, 1788.) Hence, 
unless some earlier name is found, frenatus will stand for the Mexican 
bridled weasel. 

Measurements. — An adult male from Tialpam, Valley of Mexico (type 
locality): Total length, 505; tail vertebra^ 203 ; hind foot, 53. Average 
of G males from Brownsville, Tex. : Total length, 188 ; tail vertebra', 192; 
hind foot, 51. Average of 3 females from Brownsville: Total length, 
438; tail vertebra?, 187; hind foot, 41.5. 


Tijpe from Pinahete, Cliiapas, Mexico. No. 77519, ^ ad.. V . .S. Nat. Mus., Dept. Agric. 
coll. CoHei-ted Feb. 10, 1896, by E. A. (4ol(linan. Altitude about 8,200 feet ( = 2,500 
meters). Original number 9279. 

Geof/raphh' (lisfrihution. — Mountains of southeastern Chiapas; limits 
of range unknown. 

General characterfi. — Similar to P./renaUis in size and general char- 
acters, but tail and hind feet longer; light markings more restricted; 
black of head reaching much farther back on neck; color of upper parts 
darker and more extensive, encroaching on sides of belly and covering 
fore and hind feet; black tip of tail longer. 

Color. — Upper parts, including whole of fore and hind feet, dull, dark 
chestnut brown, washed with black on the neck from shoulders forward, 
and becoming pure black on the head; face marked by a whitish i)atch 
between the eyes, and a narrow, oblique band between eye and ear; a 
blackish spot behind angle of mouth; color of under i)arts salmon 
ochraceous, reaching wrists interiorly, but not reaching heels; terminal 
third of tail black. 

Cranial characters. — Skull rather large; zygomata moderately spread- 
ing; squamosal inflation moderate, but large for a member of the/re- 
natns series; audital bulla' small, steep on inner side, and only slightly 
elevated anteriorly above squamosal inflation. The skull as a whole 
resembles that of frenatus, but differs conspicuously in the greater 
length and inflation of the postglenoid part of the squamosal, greater 
breadth of the basioccipital, and in the size and form of the audita! 

Jlne,1896,] synopsis of the WEASELS OF NORTH AMEIilCA. 2!) 

bill lie. The latter are very narrow, low anteriorly where they meet the 
iiitlated squamosal without an abrupt step, and high along the inner 

Kemarloi. — Mr. E. W. Nelson writes me that this tine weasel is found 
sparingly in the forest about Pinabete, Chiapas, at an altitude of 7,0(10 
to 8,000 feet (2,100 to 2,500 meters). The type specimen was shot in 
the afternoon while hunting on a lieavily wooded hill slope. It was 
heard making long, slow leaps over the dry, crisp leaves. Coming to a 
log, it stood up and rested its fore feet on the log, in which position it 
was shot by Mr. (ioldman. 

A specimen from Cerro San Felii)c, Oaxaca, is intcrniediiitc, both 
ill coloration and cranial characters, between typical freiKitKn and 
(johlmdni ; hence there is little room for doubt that complete inter- 
gradation exists between the two. 

Measurements. — Type specimen, male adult: Total length, 50f; tail 
vertebrie, 201 ; hind foot, 58. 


Type from Patzcuaro, JSIiohoacau, Mexico. No. 'm\i, ^ ad., U. S. Nat. Miis., Dept. 
Agric. coll. Collected July 27, 1892, l)y E. W. Nelson. Original number 2i»G0. 

General characters. — Similar to Putorius frenatus, hut slightly larger; 
black of head extending posteriorly over neck; white face markings 
much more extensive; the spot between the eyes very much larger and 
broadly confluent on both sides with whitish area between eye and ear, 
which area also is much more extensive in all directions than in 

Color. — Upper parts from shoulders to black tip of tail, dark brown; 
neck, crown of head, nose, ears, and sides of face to a little behind the 
eye, black ; black of head between eyes and ears divided by a broad 
band of bufty white which is broadly confluent with butty yellow of 
throat and chin; a narrow border of whitish on upper lip; rest of 
under parts ochraceous yellow (including whole of forefeet, inner sides 
of hind legs and feet, and terminal half or nearly half of upper surfaces 
of hind feet, where the color becomes paler, being butty ochraceous, as 
on the throat). 

Cranial characters. — Skull similar to that of fniKd us, Imt larger; 
audital bulhe much narrower; postorbital processes less strongly 

Remarlcs. — This handsome weasel presents the maximum of black 
and white markings known in the froiatus group, the black of the head 
reaching back over the neck and the white face markings covering a 
large area. In the type specimen a white stripe 50 mm. in length 
extends down the middle of the nape from a point between the ears 
more than halfway to the shoulders. This, liowever, is probably ab- 
normal, though a trace of it exists in a female from the same locality. 
This form is the poorest subspecies described in the present paper. 


Me<(siircments. — Average of 2 males from Patzcuaro (type locality): 
Total length, ~iU); tail vertebra", 201; liiiid foot, 53. An adult female 
from same place; Total length, 400; tail vertebra-, 150; bind foot, 42. 

rUTORIUS TROPIC ALIS sp. uov. Tropiuul Bridled Weasel. 

(PI. Ill, tigs., 5, rm, 6, (irt.) 

Type iVom Jico, Vera Cruz, Mexico No. oliW, <^ ad., U. S. Nat. Mu.s., Dept. Agric. 
coll. Collected July 9, 1893, by E. W. Nelson. Altitude 6,000 feet ( = 1,800 meters). 
Original number 5195. 

Geographic <lisfribution. — Tlie tropical coast belt of southern Mexico 
and Guatemala from Vera Cruz southward. 

General characters. — Similar to FutoriuH frenaiasj but much smaller 
and darker, with the white face markings less extensive, the belly pale 
orange instead of ochraceous, and under side of tail very much darker. 

Color. — Upper parts deep umber brown with a fulvous tone; head, 
ears, and neck, black, passing gradually into brown of back just iu 
front of the shoulders; terminal one-fourth (or a little more) of tail, 
black; face markings as in froiatus, but less extensive and whiter; 
under parts ochraceous buff on throat and fore feet, becoming rich 
orange buff on belly and inner side of thighs, whence (becoming paler) 
the color reaches out in a narrow interrupted stripe along the inner 
side of the hind feet to the toes, which are irregularly bufiy. 

Cranial characters. — Skull of male similar in general to that of frc- 
natiis, but smaller, relatively longer, with less spreading zygomata, less 
strongly developed postorbital processes, and probably broader postor- 
bital constriction (the type skull was infested with parasites) ; audital 
bullae smaller and very much narrower; carnassial teeth and upper 
molar smaller. The skull of the female is very much smaller than that 
of the male, and has the smoothly rounded brain case of the cicognani 
group, without trace of a sagittal ridge. The squamosals are strongly 
inflated, resembling thosG of cicognani and the female of novehoracensis. 
It differs from the female frenatus in much smaller size, very much 
smaller audital bulhe, more inflated squamosals, smoothly rounded 
brain case without trace of sagittal crest, and broader interorbital 
constriction, which is immediately behind x)ostorbital processes instead 
of one-fifth the distance from the processes to the occipital crest (fig. 15). 

Remarls. — On first examining the skins of this weasel sent home by 
Mr. Nelson, I supposed it to be merely a tropical subspecies of frenatm; 
but on comparing the skulls I am forced to accord it full specific rank. 
The difference is greatest in the females, and is really very remarkable, 
as may be seen from the accompanying figures (figs. 15 and 16). The 
female of frenatus (fig. 1(>) resembles the male of the same species (pi. Ill, 
fig. 1), while the fennile of trojricalis (fig. 15) resembles the cicognani 
group — representing another section of the genus. The case is parallel 
to that of r. noveljoracensis already described. The female of trojncalis, 
like that of novehoracensis, shows arrested development or absence of 



Fig. 15 — P. frenatus 

Fin. 10. — 1'. Iriqncalis ? . 

the specialization that characterizes the male, while the females of 
icashin(/toni and frenaUis have advanced further and are moie like 
the male. In the case of the female skulls of frenatus and tropicalis 
here figured, it is interesting to know that they were taken within 
a few miles of one another — frenatus on Cofre de Perote. at an 
altitude of about 12,500 feet; 
tropicalis at Jico on the plain 
below, at an altitude of 5,000 or 
G,000 feet.' 

The Department collecti<ui 
contains four specimens of this 
weasel, all collected by Mr, Nel- 
son in A'era Cruz. Three of 
t-liem, two adult males and one 
old female, are from Jico; the 
fourth, an immature female, is 
from Catemaco, and presents the 
extreme of differentiation in in- 
tensity of color. The hind feet 
are dark tliroughout and the color of the upper parts is peculiarly dark 
and rich, as in P. affinis. 

Measurements. — Average of two adult males from Jico, Vera Cruz 
(type locality): Total length, 442; tail vertebrie, 175; hind foot, 50. 
An old female from same place: Total length, 333; tail vertebrt^, 121; 
hind foot, 37. 


Musfehi affinis Gray: Aimals & Mag. Nat. Hist., -ith ser., XIV, p. 375, Nov. 

Type locality. — "New Granada" [= Colombia]. 

General characters. — Size large; tail long; color very dark 
black anteriorly; facial markings obsolete or nearly so. 

Color. — Upper jiarts nearly pure black on head and neck, fading 
imi)erceptibly to rich blackish brown on back, rump, and tail; black 
tip of tail long, but not strongly contrasted with dark color of rest of 
tail; under parts narrowly ochraceous orange, narrowest behind angle 
of mouth, where it is encroached on by the blackish of the cheeks. Face 
usually unmarked, but a whitish streak sometimes present in front 
ot ear. 

Cranial characters. — The only skull of this weasel I ha\e seen is from 
a skin (No. 13770, U. S. Nat. Mus.) collected by Dr. Van Patten, at San 
Jose, Costa Rica. It is immature, but differs strikingly from frenatus 
in the greater breadth of the frontal region and the flatness of the 
audital bulla'. The constriction is little marked, which may be due to 



'The ditiereuce in size of the two species is well shown by the measurements 
of these two specimens. Femaile frenaf us, Cofre cle Perote: Total length, 418; tail 
vcrtebrre, 100; hind foot, 45. Female trojncalis, Jico: Total length, 333; tad verte- 
bra-, 121 ; hind foot, 37, 


parasites in the frontal sinuses. The young skull af!'ords the, following 
measurenieuts: Basal length, 50: zygomatic breadth, 29', postjjalatal 
length, 20; i>alatal length, 24 ; iuterorbital breadth, 12; breadth across 
postorbital i)rocesses, 15; breadth of constriction, 14. 

General ronarls. — There are several specimens from Oosta Kica iu 
the National Museum collection which ajiparently belong to this 
species. In these specimens the color of the upper parts is exceed- 
ingly dark from the color of the tips of the hairs; but the color imme- 
diately underlying the black tips is deep fulvous brown, giving a very 
rich tone to the pelage. The orange of the under parts is narrow and 
does not reach the feet; on the hind legs it stops on the thighs, and on 
the forelegs it stoi)s short of the wrists. 

McdsxrciiK'itts (from dry skins in U. S. Nat. Mus.). — Total length, 
about 510; tail vertebra\ about 180; hind foot, about 52. 


Tahh of averarje cranial meanHrementu of North American WcaseU. 

F. cicognani 


P. richardsoni. 
P. alascensis . . . 
P. ttreatori 

P. rixosux 



P. novehoracetuis 

P.xvashiiiijtoni .. .. 


P. longicaxida 

P. spadix 

P. saturattis 

P. arizonensis 

P. alleni 



/'. tropicaUs 

Ossipee, N. H 

Elkliiver, Minn 


Mount Forest, Ontario. . 

Great Slave Lake 

Juneau, Alaska — 

Skagit Talley, "SVash . . . 


Trout Lake, Wash 


Osier, Saskatchewan . . . 
Point B:!rrow, Alaska . . 
Franklin Bay, Arctic 

St. Michaels, Alaska . . 


Kailiak Island, Alaska. 
Adirondacks, X. T , 


Trout Lake, "Wash 


Tarpon Springs, Fla... 
Carlton House, Sas- 


ElkEiver, Minn 


Siskiyou Mountains, 

Springei-ville, Ariz 

Boulder County, Colo.. 
Sierra Kevada, Cal 


Black Hills, S. Dak.... 


Southern California 


Tlalpam, Mexico 

Cofre de Perote, Mexico 
.Tico, Tera Cruz, Mexico 





38. 5^ 37. 5 
40. 2 39 
33.5, 32.5 
32.5^ 31.5 


33.5 32.5 

28. sj 28 

44.5 43 

43.5' 42 




38.5 37.5 
44.2 43 
38. 3 37. 5 
45.5 44 
48 47 






















18.5 10.5 
19.5 n 
16 ' 10 
16 i 9 
20.5 11.5 
21 I 14 

f^ -< 

13 i 

'' I 
IG. 5 



23 I 

22. 5 j 

22. 5 




18. 5I 

23 I 



8.7 25.5 

7.8 22 

7 j 21.5 
9.7 27 

11 i 28.5 

8.5j 23 

7.5 20 

8 22 
6.5 19 
5.5, 17.5 



14.5' 12.5' 





19. 5 











13. 5| 









11 28.5 

12 28 
10 24. 5 
10. 5 > 27 
11.3 30 






42.5 26 23 12 10.5 26.5 




29.5 26 ! 14.5 11.5 

26 I 23.5 13 
29 25 14 


44. 5' 43. 5, 
39.5 38 
42 I 40.8 
38.5 37.5 














































12.5 16.5 
11 '15 
20.5 24 

19.5 24 
19. 5I 24 
16. 5' 21 
17. 5' '24 
21.5 25.5 
16 ' 22.5' 
21 23 ! 
17.8 20.5 
21 [ 24.5 
23 25 

20.5 22.5 
23.5 24 
20.5' 23.5 
21 24 

20 22 
20.5 23.5' 


26.2 20 

24.5' 18- 







23 I 

21 ! 

22 I 

20.5 23.2 
19.5' 22 j 
24.5 27.5 






' Estimated. 

10932— No. 11- 


[Synonyms iu italics.] 

Arctogale, 9. 

('yuoinyonax (synonym of Piitoriias), 7. 

Gale (synonym of Ictis), 9. 

Ictis, subgenus, 9. 

list of species, 10. 
iluatela hrasiliensis, 20. 
tieognani, 10. 
erniinea, 9. 
enninea, 11. 
frenata, 26. 
longicauda, 19. 
ricliardsoni, 11. 
vulgaris, 9. 
rulgaris, 10. 
xanthogenys, 25. 
Putorius, genus, 7. 

key to subgenera, 7. 
list of species with type localities, 10. 
subgenu.s, 7. 

table of cranial measurements, 33. 
T'utdiius atlinis, 31-32. 

alascensis, 12-13. 
alleni, 24. 1.5-16. 
ari/.onensis, 22-24. 

Putorius boccamela, 9. 

cicognani, 10-11. 
erminea, 15, 16. 
erminea, 16. 
eversmanni, 8. 
frenatus, 26-28. 
goldmanui, 28-29. 
kadiacensis, 16. 
leucoparia, 29. 
longicauda, 19-21. 
nigripes, 7-9. 
noveboracensis, 16-18. 
oregonensis, 25-26. 
peninsula^, 19. 
piigilhts, 14. 
putorius, 8. 
richardsoni, 11-12. 
rixosns, 14-15. 
saturatus, 21-22. 
spadix, 21. 
streatori, 13-14. 
tropicalis, 30-31. 
vulgaris, 10. 
washingtoui, 18-19. 
xanthogenys, 25. 



Fig. 1. Putorius nigripts, $ ad., Trego County, Kaus. 
(Xo. 4143, Merriam coll.) 

1. Upper side of skull, 
la. Under side of skull. 
1?). Side view of skull. 

2. Putorius 2)utorius, $ ad., Brunswick, Germany, 
(No. 4661, Merriam coll.) 

2. Upper side of skull. 
2a. Under side of skull 


North American Fauna, No. 11. 

Plate I. 

1. Putorius nigripes cf ad. Trego County, Kansas. 

2. Putorius 2)utoi-ius (f ad. Brunswick. Germany. 


Fig. 1. I'liforius arcticus. Poiut Barrow, Altvska (type). 
S ad., No, 23010, U. S. Nat. Mus. 
2. Piiiorius alascensis. Juueaii, Alaska (type). 

^ ad., No. 74423, U. S. Nat. Mus., Dept. Agric. coll. 
3 aud 4. Puiorius cicotinani. 

3. ^ ad., Biicksport, Me., No. 4247, Bangs coll. 

4. 5 ad., Mount Forest, Ontario, No. 789, Bangs coll. 
5 aud 6. Puiorius strcatori. Mount Vernon, Skagit Valley, Wash. 

5. ^ ad., No. 76646, U. S. Nat. Mus., Dept. Agric. coll. (type). 

6. 5 ad., No. 76623, U. S. Nat. Mus., Dept. Agric. coll. 
7. Puiorius rixosus. Osier, Saskatchewan. 

5 ad., No. 642, Bangs coll. (type). 

North American Fauna, No. 11. 

Plate II. 

1. Putorius arcticus. 

2. P. alascensis. 

7. P. rixosus. 

3, 4. P. cicognaui. 
5, 6. P. streatori. 


Figs. 1 and 2. Putorius frenatus. 

1. (? ad., Tlalpam, Mexico, No. 50826, U. S. Nat. Mus., Dept. 

Agric. coll. 

2. 9 ad., Cofre dc Perote, Vera Cruz, Mexico, No. 54278, U. S. 

Nat. Mus., Dept. Agric. coll. 
3 and 4. Putorius longicauda. Carlton House, Saskatchewan (type locality), 

3. <? ad., No. 73183, U. S. Nat. Mus., Dept. Agric. coll. 

4. 9 ad.. No. 75483, U. S. Nat. Mus., Dept. Agric. coll. 
5 and 6. Putorius tropicalis. Jico, Vera Cruz, Mexico. 

5. S ad., No. 54994, U. S. Nat. Mus., Dept. Agric. coll. (type). 

6. 9 ad., No. 54993, U. S. Nat. Mus., Dept. Agric. coll. 

North American Fauna, No. 1 1 

Plate III 

1, 2. Futorius J'renati 

3, 4. P, loiKjicauda. 

G. P. tropicaUs 


Figs. 1 and 2. ritiorius noveboracensis. Adiroudacks, New York. 

1. S ad., No. 3843, Merriam coll. 

2. 9 ad., No. 5598, Merriam coll. 

3 and 4. Putoriu8 tvashingtoni. Trout Lake, Washington. 

3. <? ad., No. 76322, U. S. Nat. Mus.. Dept. Agric. coll. (type), 

4. 5 ad. No. 67321, U. S. Nat. Mus., Dept. Agric. coU. 
5. Puforiiis peninsula'. Tarpon Springs, Fla. 

9 ad.. No. 2.379., Ehoads coll. 

North American Fauna, No. 1 1 . 

Plate IV. 

1, 2. Jr'uturius )Lovcbonict')isis. y, 4. f, wushiiKjtoni. 5. F, peninsula:. 


Fig. 1. Putorius longicaiida (Bonap.)- 

1. S 'iil-j Cai'ltou House, SaskatclieTvan, No. 73183, U. S. Nat. Mus., 

Dept. Agric. coll. 
la. Q ad., Carltou House, Saskatchewan, No. 75483, U. S. Nat. Mus., 
Dept. Agric. coll. 

2. Putorius cicofjuani (Rouap.). 

2. J, Bucksport, Me. No, 4247, Bangs coll. 

2a. 9, Mount Forest, Ontario No. 789, Bangs coll. 

3. Putorius noveboracensis De Kay. 

3. S ad., Adirondacks, New York No. 3843, Merriam coll. 
3a. 9 ad., Adirondacks, New York No. 5598, Merriam coll. 

4. Putorius rixosHs nob. 

9 ad. (type), Osier, Saskatchewan, No. 642, Bangs coll. 

5. Putorius 2>eniH8nlw l»hoads. 

9 old, Tarpon Springs, Fla. No. 2379, Khoads coll. 

6. Putorius aicficus sp. nov, 

6. <? , St, Michaels, Alaska No, 313213, U. S, Nat. Mus. 
6rt, 9, St. Michaels, Alaska No. 36246, U, S. Nat. Mus. 


North Ameiican Fauna, No. 11. 

Plate V. 



INTo. 1 


[Actiuil tUite of publication, July 23, 18116.] 




Prepared under the directiuu of 





United States Depart3Ient of Agriculture, 

Division of Ornithology and Mammalogy, 

Washington, D. C, ^laij 12, 189G. 
Sir : I have the bouor to trausmit herewith, and recommend for pub- 
lication, the manuscript of l!^o. 12 of North American Fauna, treating 
of the Genera and Subgenera of Voles and Lemmings, and comprising 
results of investigations carried on in the Division of Ornithology and 
Mammalogy by Gerrit S. Miller, jr. 


C. Hart Merriam, 

Clilef of Division. 
Dr. Chas. W. Dabney, Jr., 

Acting Secretary of Agriculture. 




Introduction.... 7 

The subfamily Microtincr and its main divisions 8 

List of genera and subgenera of Microthup 9 

Geographic distribution 9 

Habits 10 

Nomenclature 11 

History of former classifications 19 

Characters on •svhicli the jiresent classification of the sul)geuera oi Mi trot us is 

based 24 

Keys 28 

Descriptions of living genera and snl)geuera 32 

Descrijitions of extinct genera and suijgenera 73 

Note on 'Arvicohi ' iniermedius Newton 75 



1. Skulls of Microtus macropiiH, 3/. pinetorum, M. arvalis, M. curtatiis, M. oregoni, M. 

tvrresiris, M. albicauda, 21. fertilis, Evotoinys (lapperi, Pheuacomys oramonds, 
Lemmus nigrijjes, Sijnaptonujs u'ranrjeli, S. helaletcs, Dicrostonyx torquatus. 

2. Hony palates of Phenacomys. Mlcrotns, Laguru-s, Pitymys, Arvicola, Alticola, 

Anteliomys, Eothenomys, Evotomys, Xeofiiei; Dicrostonyx, Lemmus, Fiber. 

3. Mandil)les of Sy'naptomy.<<. Phenacomys, Microtus. Evotomys. 


1. First upper molar of six specimens of Microtus pennsylvanicus. 

2. Second upper molar of six specimens of Microtus pennsylvanicus. 

3. Third upper molar of eighteen specimens of Microtus pennsylvanicus. 

4. First lower molar of eighteen specimens of Mierotus pennsylvanicus. 

5. Second lower molar of four specimens of Microtiis i)ennsylvanicus. 

6. Third lower molar of four specimens of Microtus pennsylvanicus. 

7. Palatal view of skull of Microtus arvalis and Evotomys gapperi. 

8. Enamel pattern of molar teeth of Synaptomys cooperi. 

9. Palatal view of skulls of Synajjtomys aud Mictomys. 

10. Enamel pattern of molar teeth of Synaptomys innuitus. 

11. Enamel pattern of molar teeth of Lemmus lemmus. 

12. Left front foot of Lemmus lemmus. 


13. Enamel pattern of Dicrostonyx from Ungava. 

14. Ear of Dkrostonjix and Lemmus. 

15. Left front foot of three sjjecimens of iJicrostonyx from Alatska, showing seasonal 

change in form of middle claws. 

16. Side view of molars of adult and young Phenacomya. \ 

17. Enamel pattern of molar teeth of Fhevacomys celatua. 

18. Side view of molars of adult and youug Evoiomys. 

19. Enamel pattern of molar teeth oi Evotomys gapperi. 

20. Side view of molars of adult Microtus. 

21. Left front foot of Microtus terrestris. 

22. Enamel pattern of molar teeth of Microtus {Eothenomys) melanofjaster. 

23. Enamel pattern of molar teeth of Microtus (Anteliomys) chiiiensis. 

24. Audital bulla' of Microtus (Microtus) arralis and M. (Layurus) 2}allidus. 

25. Enamel iiattern of molar teeth of Microtus (Layurus) luteus, M.{L.) lagurus, and 

M. (L.) palUdus. 

26. Enamel pattern of molar teeth oi Microtus (Jliicola) alhicanda. 

27. Audital bullfe of Microtus (Alticola) albicauda and M. {Hyperacrius) fertilis. 

28. Enamel pattern of molar teeth of Microtus {Hyperacrius) fertilis. 

29. Enamel pattern of molar teeth of Microtus (Pedomys) austerus, 

30. Enamel pattern of molar teeth of Microtus (Phaiomys) strauchi. 

31. Enamel iiatteru of molar teeth of Microtus {Pitymys) pinetorum and M. (P.) savii. 

32. Enamel pattern of molar teeth of Microtus (Chilotus) oregoni. 

33. Enamel pattern of molar teeth of Microtus (Microtus) arvalis, M. (M.) nivalis, M. 

(M.) penufsylvanicus, and J/. (M.) ratticeps. 

34. Enamel pattern of molar teeth of Microtus (Arvicola) terrestris and M. (A.) 


35. Enamel pattern of front lower molar of type of Microtus arvicoloides. 

36. Enamel pattern of molar teeth of Microtus (Xeofiber) alleni. 

37. Dorsal view of skull of Fiber. 

38. Side view of molars of adult Fiber. 

39. Enamel pattern of molar teeth of Fiber zibethicus. 

40. Enamel pattern of molar teeth of '^/'luco/a' interrnedius. 

No. 12. NORTH AMERICAN FAUNA. July, 1896. 


By Gekrit S. Miller, Jr. 

The followiug revision of the genera and subgenera of voles and lem- 
luiugs is chiefly the result of a study made in the Division of Ornithol- 
ogy and Mammalogy of the collections belonging to the United States 
Department of Agriculture. This material has been supplemented by 
specimens from my own i^rivate collection and those of Mr. Outram 
Baugs, Mr. S. N. lihoads, and Dr. C. Hart Merriam. I have also had 
access to the voles and lemmings in the American Museum of Natural 
History, the United States iSlational Museum, and the British Museum. 
Thanks are due to all who have placed material at my disposal, and 
especially to Mr. Oldlield Thomas, curator of mammals in the British 

Hitherto no attempt has been made to com])are in detail the voles 
and lemmings of the Old and New Worlds. This is the necessary result 
of the poor quality and small number of specimens from the opposite 
side of the Atlantic to be found in museums and private collections in 
both Europe and America. In consequence of this lack of material, 
writers who have been thoroughly acquainted with indigenous voles 
and lemmings have either made no comparison of these with exotic 
forms, or have reached faulty or at least incomplete conclusions with 
regard to groups occupying widely separated geographic regions. 

For determining the relationships of the different voles and lemmings 
the collection in the British Museum offers exceptional facilities. It 
contains representatives of all the recent genera and subgenera found 
in the Old World, and lacks only one of those peculiar to America. 
The collection is, moreover, especially rich in specimens identified by 
the more prominent writers on the subject — a circumstance of the 
utmost importance. 

The drawings for the illustrations in this paper, except fig. 9 and 
Pis. I and II, were made under my constant supervision by Mr. F. 
Miiller. Pis. I and II were prepared by Dr. James 0. McOonnell. 
Figs. 4, 5, 8, and 10 of PI. II were drawn in ink by Dr. McConnell from 
pencil drawings made at the British Museum by Mr. Hollick. Fig. 7 
of the same plate is by Dr. ]McConnell from a pencil drawing by Mr. A. 



Westergreii. The tracings of the enamel pattern of Microtus htteiis 
and ]\L lagnrns are enlarged from flgs. 10, 11, 15, and 16 of PI. XIII of 
Biicbuer's 'Wissensclmftliclie Eesnltate der von N. M. Przewalski nacb 
Central-Asien nnternommenen Eeisen.' In fig. 22 the enamel patterns 
of the front lower molar and middle and back upper molars are enlarged 
from Mr. Hollick's pencil drawing of a specimen from Fokien, China 
(British Mnsenm Register 92. 10. 12. 52), the other teeth from fig. 1, PI. 
XLYI of Milne-Edwards's '■ Recherches jiour servir a 1' Histoire Natnrelle 
des Mammiferes.' Fig. 23 is compounded in the same way from Mr. 
Hollick's drawing and the original figure published by Thomas. 


The subfamily Microtince^ is a group of murine rodents closely related 
to the Keotomincc, Cricefince, and MyotaJpincv.'^ It is distinguished from 
the first and second by cranial and dental characters; from the last 
chiefly by peculiarities in external form.^ While it is not the purpose 
of the present paper to discuss the relationships of the Microtina' to 
any of these, it is important to consider in some detail the larger divisions 
of the subfamily itself before taking up the genera and subgenera. 

The members of the subfamily Microtina' fall naturally into two 
supergeneric groups, the Lemmi and Microti, or lemmings and voles. 
The former includes the genera Synaptomys, Lemmus, and Dicrostonyx, 
the latter the genei'a Phenacomys, JEvotomys, Microtus, and Fiber. 

Lemmi. — Skull generally broad and massive; lower incisors short, 
with roots ending on inner side of molars (PI. Ill, fig. 1); crowns of 
maxillary teeth scarcely, if at all, narrower posteriorly than anteriorly 
(figs. 10, 11, and 12); tail usually shorter than hind foot (in Synaptomys 
slightly longer); palms and soles usually without distinct tubercles. 

Microti. — Skull comparatively slender and lightly built: lower 
incisors long, with roots ending on outer side of molars (PI. Ill, figs. 2 
and 3); crowns of maxillary teeth distinctly narrower posteriorly than 
anteriorly (figs. 17, 19, 21-35); tail usuallj' much longer than hind foot 
(in the Asiatic species of Lngurus distinctly shorter) ; palms and soles 
always with distinct tubercles. 

In external appearance the lemmings and voles differ considerably. 
The former are mostly thick-set animals, with powerful fossorial feet, 
long, dense fur and very short tails, while the latter are more slender, 
with longer tails and with the fur and feet not so highly modified. 

^ =^ ArrieoUna' Auct. This name, however, must be abaudoned, together with the 
generic name Arvicola (see p. 14). 

'^ = Sij)hneinct3 Auct. As SipJineus (Brants, 1827) must give place to Myotalpa (Kerr, 
1792) (see Allen, Bull. Am. Mus. Nat. Hist., New York, VII, p. 183, 1895) it is neces- 
sary to make a corresponding change in the name of the subfamily. 

•The characters separating the Miiotalpinw from the Microtiniv are of much less im- 
portance than those separating the latter from auy of its other allies. So close, indeed, 
is the resemblance between the two that it may eventually prove necessary to unite 
them under one name. Lack of material jjrevents auy final conclusion at present. 

Jl-LY, 1896.1 



Altbougb the voles and leuimiiigs may usually be distinguished at a 
glauce, there are certain genera and subgenera the exact position of 
which is not at first apparent. Thus the species of Lagnrns, although 
volCvS, so closely resemble lemmings in exteriml appearauce that their 
true relationships have been only very recently detected. On the 
other hand, Synaptomys, a true lemming, has much the superficial 
appearance of certain forms of Microtus. 






















Synaptomys cooperi. 
Synaptomys inuuitus. 
Lemmus lemmus. 
Dicrostonyx torquatus. 
Pbenacomys intermedins. 
Evotomys rutilus. 
Microtus arvalis. 
Microtus melanogaster. 
Microtus cbinensis. 
Microtus lagurus. 
Microtus stoliczkanus. 
Microtus fertilis. 
Microtiis blythii. 
Microtus austerus. 
Microtus pinetorum. 
Microtus oregoni. 
Microtus arvalis. 
Microtus terrestris. 
Microtus alleni. 
Fiber zibetbicus. 

The following groups are known to occur in both hemispheres: 

Lemmus. Microtus (gouns and subgenus). 

Dicrostonyx. Lagurus. 

Phenacomys? Pitymys. 

Evotomys. Arvicola. 

The following groups have been found in the Old \Torld only: 
Eothenomys. Alticola. 

Anteliomys. Hyperacrius. 


The following groups have been found in America only: 
Synaptomys. Cbilotus. 

Mictomys. Neofiber. 

Pedomys. Fiber. 


The subfamily Microfinw is distributed throughout the extratropical 
region of the Northern Hemisphere. In the north some members of 
the group approach the extreme limit of mammalian life, while in the 
south a few si)ecies enter the northernmost edge of the tropics. The 
subfamily, which is clearly boreal in origin, reaches its highest develop- 


ment in temperate Europe, Asia, and North America. Altliougli it is 
probable that no species are common to both continents, five f?enera 
and four subgenera of the genus MlcrotKs have a circumpohxr distribu- 
tion. On the other hand, no genera are peculiar to the Old World, and 
only two are confined to America. Asia has five subgenera of Microtm 
not found in America, and America has three not known to occur in the 
Old World. 


The voles and lemmings occur in great abundance throughout the 
region which they occupy. They live in an endless variety of situa- 
tions, from sea beaches to marshes and Alpine mountain tops, and from 
open ijlains to the densest forests. They are, perhaps, most numerous 
in Avell-watered grass lands. In localities where they are abundant 
most of the species make their presence Icnown by trails or runways 
traced through the vegetation near their barrows. Occasionally, how- 
ever, they occupy hollows in decaying logs or among loose rocks, and 
use natural crevices instead of beaten paths. While the great majority 
of species spend much of their time on the surface, protected by the 
overhanging vegetation, a few live almost exclusively underground, 
and in consequence of this habit have ac(iuired numerous modifications 
which fit them for the needs of a subterranean life. Others are 
amphibious and never occur at any great distance from water. At 
least one member of the subfamily^ is said to live among the branches 
of trees. The food is chiefly vegetable, though most species occasion- 
ally eat animal food. The vegetable food consists principally of grass 
stems, though roots, bark, leaves, seeds, and fruit are at times eaten in 
varying (quantities. xVs voles are readily caught in traps baited with 
meat, it is probable that flesh forms part of their normal food. Mollusks 
are eaten freely when they can be obtained. 

The voles and lemmiugs breed very rapidly during the warmer part of 
the year. The number of young in a litter varies from one or two to ten. 
Five is, perhaps, the average number in the majority of species, though 
it is probably less in those in which the females have only four mamma?. 

' Phenacomys longicauda True, from Oregon. In the original description of the 
species (Proc. U. S. Nat. Mu.s., XIII, pp. 303-304, Nov. 15, 1890) Mr. True quotes as 
follows from a letter from Mr. Anrelius Todd, who collected the type specimen: "It 
lives exclusively, as far as I have been able to ascertain, among the boughs and 
branches of the Oregon pine trees (Abies douglasi), making a nest of a size smaller 
than a robin's It is usually situated on the ui:)per side of a medium-sized 
branch, perhaps 6 inches in diameter, and is composed of the leaves of the tree 
deftly split in two from one end to the other and dried. The nest is neatly and 
rather ingeniously made, and the sameness of the material is a novelty. * * * 
The mouse is almost exclusively arboreal in its habits, but I think that I have reason 
to believe that they sometimes come to the ground for food, as I have seen tracks iu 
the snow around the trees which I think were made by these little animals. They 
could be tracked up and down the tree, but to no great distance from it, and were 
most likelv in search of food." 

July, 1896.] NOMENCLATURE. 11 

The 5'oung- are boru in nests made of soft vegetable libers. The nests 
are usually placed iu a burrow or beneath shelter of some kind and 
vary witli the size of the animals, but are usually about 200 mm. in 
diameter. The species of Fiber make nests containing several bushels 
of material. These are conspicuous objects in the marshes where the 
animals live. Under conditions the nature of which is not understood 
the rate of increase in certain species is occasionally so enormously 
accelerated that an area becomes overcrowded and the animals wander 
into the surrounding country in search of food. So far as known, such 
'lemming mig'ratious' and 'vole plagues' are phenomena peculiar to the 
Old World.' 


Before considering the characters of the genera and subgenera of 
Microtintc it is necessary to examine a considerable jDart of the mass of 
technical literature to which, during the past hundred and forty years, 
the animals in question have given rise. Since Linmieus published the 
tenth edition of the Systema ]Satura) more than fifty names have been 
used for the less than two dozen namable superspecific groups recog- 
nizable in the subfamily. In considering their claims to recognition 
the names may be best taken up chronologically. 

Mns Linnajus, 1758 (Syst. Xat., Ed. 10, p. 59), contained the following 
species: Porcellus, leporinus, lemmus, marmota, monax^ crieetiis, terres- 
tris, ampMMus^ rattus, musculus, aveUanarius, sylvaticus, striatusj lon- 
gi2)€s,jaculus, volans. Since two'^ of these {lemmus and terrestris) are 

■An account of the migrations of Lemmus hmmus in Norway is given by Prof. R. 
C'ollett in Christiania Videnskabs-Selskabs Forbandlinger, 1895, No. 3. 

For description of a vole plague in Scotland, see Report of the Departmental 
( omiiiittce appointed by the Board of Agriculture to inquire into a Plague of Field 
Voles iu Scotland. London, 1893. 

-Appareutly three, but terrestris and ampliihius are, as Lataste has already shown, 
the same animal. The Mus amphiiius of Linnams is nothing more than a hgment of 
the imagination based on Ray's misconception that there is a large aquatic vole with 
webbed feet. 

Since the matter is of importance as determining the validity of the current name 
of one of the most common European mammals, I ([uote Linn;eus's descriptions in full : 

"[Mus] terrestris, 7. M. cauda mediocri subpilosa, palmis subtetradactylis, 
idautis pentadactylis, auriculis vellere brevioribus. 

"Mus cauda longissima pilosa, auribus subrotundis vellere brevioribus. Fn. svec. 
29. Syst, Nat., 10, n. 5. 

"Mus agrestis, capite graudi, brachiuros. Raj. quadr. 218. 

"Habitat iu Earop;i' terra et aqua. 

"Corpus fuscum subtus pallidum, at non albicans. Caput crassius, ore gibbo. 
Cauda magis pilosa, quam iu Ratto, sed corpore dimido brevior, a pedibiis fere longior. 

"Hortos Talpje instar misere effodit palmis licet jiarvis; natat in fossis et urinatur 
plantis licet fissis ; Radices arborum decorticat, ])lantaruui consumit s. aufert ; Pullos 
anatum in pisciuis occidit. 

" [Mus] amphibius, 8. M. cauda elongata pilosa, plantis palmatis. 

"Mus major aquaticus s. Rattus aquaticus. Raj. quadr. 217. 

"Mus aquaticus. Beil. aquat. 3.5. t. 36. 


Microtiiies, it is necessary to see whether the name can be applied to 
any genus of the subfamily. Linnaeus of course designated no type, 
but subsequent usage has fixed the n;mie on the congeners of 31}is mns- 
cuIks. As no sound principle of nomenclature is thus violated, the 
name Mus should be kept in its present signification. 

Castor Linn.Teus, 1758 (Syst. ^N^at., Ed. 10, p. 58), was originally pro- 
posed for the species fiber and moschatus, but in the twelfth edition 
of the Systema others were included, among them the muskrat. The 
name, however, could by no process of subsequent elimination be applied 
to the latter. 

GJis Brisson, 17G2 (Regn. Anim., pp. 13, 113), is clearly l)ased on 
the dormice,' although the genus includes 'la Marmotte de Bahama,' 
'laMarmotte d'Amerique,' 'la Marmotte de Pologne,' 'la Marmotte des 
Alpes,' and 'la Marmotte de Strassbourg,' in addition to 'le Loir,' 'le 
Lerot,' and 'le Croquenoix.' The name must, therefore, take the place 
of Myoxns Schreber, 1781, commonly used for the dormice.^ As none of 
the species of Brisson's Glis are Microtines, the name would not be men- 
tioned here were it not for its bearing on Glis Erxleben, 1777.^ (See p. 13.) 

CunicuJns Brisson, 1762 (Eegn. Anim., p. 13), must also be consid- 
ered, because it invalidates the use of Cuniculus Wagler as the generic 
name of a lemming (see page 16).* The genus contained an assemblage 
of forms which are now put in six genera distributed among five fami- 
lies. Dr. C. Hart Merriam has recently shown (Science, n. s., I, p. 

[Continuation of note from page 11.] 

"Habitat in Europ.-p, Africne fossis, ripis, piscinis, hortis. 

" Species mihi iion rite cognita. 

"Fodit ad fossas et radicis arborum, natat, urinatiir, consumit radices, Hortis et 
satis infestus, capitur Nassis e virgulis confectis sub aqua demersis." 

The description of Mus terrestris is extended and applies to the water rat in every 
particular, while the diagnosis of M. ampldh'ms is very brief and contains a glaring 
error in the assertion that the animal has webbed feet. That the common water rat 
was the animal which Linnivus had in mind when he described Mus ierresiris is 
shown by the length and accuracy of the description and by his choice of the sjiecific 
name {Mus terrestris is the Latin e([uivalent of the Swedish jordratta). That he 
never saw 'Mus amphibius' is clearly indicated by the statement: "Species mihinou 
rite cognita." It is thus evident that there is no excuse for retaining the specific 
name amphibius, even though the error through which it is now generally ;ised has 
passed current for nearly a century. 

'In the Tabula Synoptica Quadrupedum secundum Ordines Sectiones et Genera, 
on pages 12 and 13, the name is introduced as follows: 

Cauda longa, vestita pilis ita dispositis at caudum iilanum efflciant Sciurus 

Cauda longa, vestita pilis ita dispositis at caudum rotundam efificiaut GU$ 

-See Merriam, Science, n. s., I, p. 376, April 5, 1895. 

'^Glis Brisson also antedates Glis Storr (Prodr. Meth. Mamm. 1780, p. 39), proposed 
for Mus tamaricinus, M. longipes, M. cafer, M. sagitta, M. jaculus, M. nitidula, M. 
avellayrarius, and M. gJis. 

•"In the synoptic table (pp. 12, 13) the name is introduced as follows: 
Cauda brevissima vel nulla: 

Auriculis longis Lepus 

Auriculis brevibus vel nullis Cutiicuhts 

July, 1806] NOMENCLATUKE. 13 

376, 1895) that by elimination Gimiculus cauda longissima Brissou 
[ = I)i})us (tiactaga Olivier; becomes the type. The name is thus unten- 
able for any of the 2Iurlda\ although Lemmm lemmus is one of the spe- 
cies included by Brisson in the genus. 

GUs Erxleben, 1777 (Syst. Eegn. Anim., p. 358), contained marmota, 
monaXj canadensis, tscherkessicus, zemnii, lemmus, migratorius, barahensis, 
arenarius, lagurus, and ceconomicus [—Mus songarus Pall.]. Although 
this genus contains two lemmings, the name need not be considered, 
since it is preoccuijied by GUs Brisson, 1702. 

Arctomys^ Schreber, 1780 (Plates to Schreber's Siiugth., CCVII- 
CCIX, 1780), contained the following species: marmota, moiiax, hohac, 
empetra, and citiUus. Of these the first four belong to the genus A rc/oMiys 
as now understood, and the last to Spermoijliilus. The latter genus was 
defined in 1823 by F. Cuvier (Dents des Mammiferes, 1823, 1G0-1G2, 
255), who restricted the nauie Aretomys to the group to which it is now 
applied. Aretomys Schreber is mentioned here only on account of: 

Lagomys Storr, 1780 (Prodromus Methodi Mammalium, p. 39). 
Although Storr and Schreber bear the same apparent date, it appears 
safe to take Schreber as the earlier, since Storr alludes to the genus 
Aretomys, aud refers directly to the ^^[us glareolus Schreberi,' a species 
published at the same time.^ Storr evidently proposed Lagomys merely 
as a substitute for Aretomys, a name which he considered inappropri- 
ate, because the animals to which it was applied resemble hares rather 
than bears.^ It is thus a synonym of Aretomys and requires no further 

Myoeastor Kerr, 1792 (Animal Kingdom, 1, Mamm., Syst. Cat. Nos. 
458-521), included the coypu and muskrat. Xo type was designated, 
but subsequent elimination fixed the name on the coypu. (See i>. 14.) 

Ondatra, Link, 1795, (Zool. Beytrage, Vol. I, Pt. II, p. 76), contained 
the same species as Myoeastor Kerr, of which the name is thus a 

Lemmus Link, 1795 (Zool. Beytrage, Vol. I, Pt. II, p. 75), has escaped 
the notice of recent writers. Vague references to it occur in works 

'This name is apparently antedated by Marmota Blumenbach ("Haudb. d. Natur- 
gesch., 1779," fide Agassiz). I have been unable to verify the reference, and do not 
know what species were included by Blumenbach iu the genus. 

-On the dates of the parts of Schreber's S.'iugthiere, see Sherborn, Proc. Zool. Soc, 
London, 1891, 587. 

■"Sequuntur in eundeni finem nomina specierum, laudato Pallas pariter ad mures 
tractaruni, quae luihi genus constituerunt, Lagomys, nee Aretomys dictum, nam 
Lepori aptius quam Urso, comparari jiosse videantur. Dicendie species nomini- 
bus 111. Pallas ieque adhibitis, ha>c suut; J/, arenarius, M. songarus, AT. furaii- 
culus, J/, cricitus, M. accedula, M. phwiis, 21. lagurus, 21. gregaVis, 21. socialis, 21. 
oeconomus, 2f. rutilus, 21. glareolus Schreberi, J/, monax, 21. marmofa, 21. empetra, 21. 
arctovvjs, J/, citillus, 21. lemmus, 21. torquatvs, 2T. hudsonius, 21. taljnnus, 2f. capensis, 
21. aspalax, 21. typclus" (sic). 

^Lagomys Storr of course antedates Lagomys Cuvier, 1800, the current name for the 


of the early part of the preseut century, but of late all traces have dis- 
appeared, Lataste (Le Naturaliste, Tome II, p. 47.'3, 1882). after a long 
and fruitless search, concluded tliat the name had probably never been 
published, and that the references of the older authors were merely to 
Link's manuscript. Mr, Oldfield Thomas has discovered Link's book 
and linds that the genus Lemmus contained the species socialis, hif/urus, 
Jemmus, torqi<ati(s, f/lareolxs, and hndso^iiKS,^ representing the modern 
genera Lemrnvs, Dk-rosiony.i\ Microfns, and Evotnmys. As the name 
Lemmus has been restricted by subsequent authors to the species 
lemmus and its near allies, a group to -which no other generic name has 
been specially applied, it must be retained in this sense,- 

Microtus Schrank, 1798 (Fauna Boica, p. 72), included M. terrcstris, 
M. amphihius [=M. terrestris Linn.), and ilf. '(/regarius.'' The Microtus 
terrestris of Schrank is not the Mus terrestris of Linnanis, but the com- 
mon field mouse of Central Europe, Microtus arralis (Pallas). J/, gre- 
gurius Schrank, apparently based en one specimen from Bettbrnnn, is 
probably a young 21. arralis. The third species, M. amphihius, is the 
water rat, Microtus terrestris (Linnaeus). Thus the genus Microtus 
originally contained two species, arralis and terrcstris. As the latter 
was made the type of Arvicola by Lacepede in 1801. arralis nmst be 
taken as the type of Microtus. 

Fiber Cuvier, described in 1 798 but not named until 1800 (Tabl. f^lem. 
de I'Hist. ^i\t. d. Anim, 111, 1798; Lecons d'Anat. Comp. I, Tabl. I, 
1800), is the first and only generic name based exclusively on the musk- 
rat, Cuvier, in establishing this genus, eliminated Fiber zibethicus from 
Myocastor, and thus fixed the latter name on ^1/. coypu. (See page l-").) 

Arvicola Lacepede, 1801 (Mem. de I'lnst., III., Paris, 1801, 489-^), was 
based on Arvicola amphihius { = 2[us terrestris Linn.) alone, and not on 
the European voles in general, as often supposed.^ Although the name 
Arvicola can not be used in a generic sense, it is available fur the sub- 
genus of which Microtus terrestris is the type. 

Hypurhcus Illiger, 1811 (Prodr. Syst. Mamm. et Avium, ]i. 87), con- 
tained the species lemmus. ampliibius {=terrestris), and arr((lis, or the 
modern genera Lemmus and Microtus. As no type was designated, and 

' Mr. Thomas has kiudly seut me a co^jy of the original diagnosis. It is as follows: 
"Gen. 8 Lemmus, Lemming. Die Thiere dieses Gesr-hlechts kommen mit den vorigen 
[Mils'] sehr ueberein, aber die Ohren sind viel kleiner nnd abgerundet, der Korper* 
gedrungener, die Beiue verhiiltnissmiissig kiirzer, der Schwanz sehr kurz. AucBj- 
weichen sie in der Lebensart von den vorigen ab. Sie niiheru sich Arctomys. Hieher 
gehitren: Mus socialis, Ingurus, lemmus, torqudfus, (jlareoJus, liudsoiiius." 

-See note on the names llraclnjurus, Mi/odes, Hijpudaus, and Lemmus, in Actes de la 
Societc Scientitiqne du Chili, Tome V, iip. XX. XXI, 1895. 

3 This is sometimes quoted: "Tableau des divisions, etc., de la class des mamnii- 
feres, 1799." The paper was "lu le 21 prairial an. 7,'' though not published untill801. 

■•Lacepi'de's description is as follows: "44 Cnmpagnol. Deux iucisives superieurs 
non comprimees; deux incisives inferieurs tranchantes; molaires sillonn<^es; jjoint 
d'abajoues; queue velue. Camjiagnol aciuatiqae — Arvicola amiihibius." 


as both Lemmus and Microtus were included in the then undivided 
geuus Ijcmmn.s Liuk, the uame Hypmhvus juust lapse into sjniouymy. 

Myodcs Pallas, 1811 (Zoog. Eosso -As., I, p, 172), embraced ten spe- 
cies, now placed in four geiiera. The species are: Lemmus, forquatvs, 
lagums, a^conomns, arvaJis, saxatUi.s, gra/aUs, sociali.s, alliarivs, and 
rntiJus: the genera : Lemmus {lemmus), Dicrosfonyx {torquatus), Microtus 
{a'cono7nus, arralis, saxatiUs, grecjaUs, sociaUs, alUarius, Jagurus), and 
Evotomys ( rut this). Since Myodes contained species of exactly the same 
modern genera as Lemmus Link and no groups not included in the lat- 
ter, the name is a synonym of Lemmus. 

Braehyiirus Fischer, ISlo (Zoognosia, I, 3d ed , pp. 14, iil; JU^ 1814, p. 
5.5), contained the species: arralis, rutilus, am2)hihius, lemmus, torquatus, 
alUarius, hJumenbachii, fulvus Geoffroy, niloticus Geoffroy: also the 
' species dubia- ' : zemni, gregar'ms, sociaUs, lagurus, wcouomus. The uame 
is a pure synonym of Lemmus Link, uidess it may be applied to some of 
the exotic or dubious species.' 

Ahnceola Blainville, 1817 (Xouv. Bict, d'Hist. Xat., IX, p. 287), i:)ro- 
posed for ' le Genre Campaguol ' is probably an erratic misprint for 
Arvicola. Xo type is mentioned. 

Mynomes Rafinesque, 1817 (American Monthly ^Magazine, II, p. 15) 
was based on Wilson's figure of the common meadow mouse of the east- 
ern United States. The name is thus a synonym of Microtus Schrank 
as Microtus arralis and M. 2)cnnsylranicus can not be separated sub- 

Psammomys LeConte, 1830 (Ann. Lye. Xat. Hist., :N". Y., Ill, p. 132) 
is tlie first name proposed for the subgenus containing Microtus pine- 
tor nm. It is, however, preoccupied by Psammomys Cretzschmar, 1828 
(Atlas zu der Eeise im Xordl. Afrika. Iste Abtli., Zool. (182G), Heft XI 
1828, p. 50. Type Psammomys ohesus Cretzschmar) and so can not be 
used here. The date of Psammomys LeConte is usually quoted as 1829, 
but the paper on this genus, although read on December 21, 1829, was 
probably not published until after the end of January, 1830, since papers 
read January 11-25, 1830, are included with it in one signature. 

Pitymys McMurtrie and Ammomys Bonaparte both appeared in 1831. 

McMurtrie (American ed. Cuvier's Eegne Animal, I, p, 434) pointed 
out that Psamiuomys LeConte is preoccupied, and for this name substi- 
• tuted Pitymys. Bonaparte (Saggio Distrib. Metod. degli Anim. Vert., 
p. 20, footnote) after showing that LeConte's name Psammomys is not 
tenable, proposed to change it to Ammomys, thus preserving the original 
meaning of the word.^ It is impossible to tell which name is the earlier, 

j 'This name has been supposed to be preoccupied bv ISrachi/unis Spix (Lataste 
i Ann.Mus.CiY.St.Nat. diGenova, XX, p. 264; Biiclmer, Wissenscb. Result, der von 
j N. M. Przewalski unternomm. Reisen, I, p. 127). Spix's uame, however, dates from 

1823 and woukl in no way invalidate Jirachiptrus Fischer, were the latter on other 

grounds tenable. 

Preudiamo la liberta d' iutrodurre una piccola mutazioue ortografica uel noma 
dato al nuovo genere dal 8ig. LeConte, la quale nou ne canibia per., il siguificato." 


but in the imcertainty Pitymys slioiikl be retaiued as tlie one adopted 
by all subsequent writers. 

Cuniculus Wagier, 1830 (Nat. Syst. d. Anipliibien, p. 31), included 
three species {G. lemnius, C. torquatus, aud ('. <(.sp((Iax) now referred to 
three genera and two subfamilies. The name has been commonly 
applied to torquatus and its congeners, but its use is invalidated by 
Cuniculus Brisson, published fifty-eight years before. 

Hemiotomys DeSelys-Longchamiis, 1830 (Essai monograph, sur les 
Campagnols des environs de Liege, p. 7), was i)roposed as a section of 
Arvicola (=Microtus) to include the species fulvus {=arvalis) and 
ainpMhius { = terrestris). As each of these had already received a ten- 
able subgeneric name, Hemiotomys lapses into synonymy. 

Pinemys Lesson, 1830 (Hist. i!^at. d. Mamm. et Ois. decouv. depuis 
1788, Compl. ffiuvres de Buffon, V, p. 130), based on Psammomys pine- 
torum LeConte, is a synonym of Pitymys McMurtrie. 

Lagurus Gloger, 1811 (Gemeinniit/. Hand- u. Hilfsbuch d. Natuige- 
schichte, 1, pp. XXXI, 97), is the earliest available name for the sub- 
genus of which Mus lagurus Pallas is the type.^ (See footnote, p. 1!>.) 

Dicrostonyx Gloger, 1811 (1. c, pp. XXXI, 97), is the tenable name 
for the genus usually known as Cuniculus Wagler.^ This name has 
escaped notice until very recently.^ 

Neodon Hodgson, 1819 (Ann. & Mag. Xat. Hist., 2d ser., Ill, p. 203), 
is a synonym of Micnrtus, as its type, N. .siTclci^nensis Hodgson, can not 
be separated subgenerically from Microtus arvalis. 

'■'■ Myolemmus Pomel, 1851 (Ann. Sci. Soc. Auv'ergne),-' is a synonym 
of Dicrostonyx Gloger. This statement is made on the authority of 
Trouessart (Cat. Mamm. viv. et foss., Rodentia, Ft. II, p. 150, 1881), as 
I have had no opportunity to verify the reference. 

Misothermus Hensel, 1855 (Zeitschr. der Deutsch. geolog. Gesellsch., 
VII, p. 492), is stated by the author to be based on Myodcs torquatus 
Pall. It is thus antedated by Myolemmus Pomel and Dicrostonyx 

Pedomys, CMlotus, and Synaptomys are three names proposed by 
Baird in 1857 (Mamm. X. Am., pp. 510, 517, 558). All are tenable for 
the groups to which they were applied. Pedomys and Chilotus are sub- 
genera of Microtus. Their types are Microtus austcrus and 2[. orcgonus, 
respectively. ^Synaptomys is a genus, with aS'. cooper! as the type. 

'Gloger'e description is as follows: " Theils aaf dem Ural und anderen Gebirgen, 
tlieils audi in tieferen Gegeudeu Sibiriens, giebt es, drei oder vier andere Artcn niit 
kleiueu, rundlicbeu oder spitzigen Daumniigelu uud von einfacherer F.'irbnng 
(Laf/urus), die ziim Tbeile nicbt weuiger zum Wauderu geneigt scheinen. Z. B. L. 

•Gloger says: "Von den uordamerikaniscben Lemiuiugeu zeicbuen sicb niauclie 
durch eiu Paar hocbst sonderbare (gleicbsam doppelte) Vorderkralleu aiis, die 2 od»T 
gar 3 Spitzeu iiber einander zu habeu sebeinen, weil sie uuter den Nageln grosse, 
barte Ballenbervorragungen besitzen. Sie kuunen daber Gabelkraller (Dicrostonyx) 

^For a paper on Gloger's generic names for maunuals, see Tbomas, Ann. A. Mag- 
Nat. Hist., 6tb ser., XV, Feb. 1, 1895. 

July, 1890.] NOMENCLATURE. 17 

Falu(Ucola Bhisius, 1857 (Fauna der Wirbelth. Deutscbl., Bd. I, 
Siiugetbiere, p. 333), a subgenus o£ Arricola { = 2Ucrotus), contained tbe 
species: amphibii(s { — terrestr is), nivalis, and ratticeps. As tbe first is 
a member of tbe subgenus ArincoJa and tbe otbers eacb a true Micro- 
tiis, tbe name can not be used. Moreover, it is preoccupied by PalKdi- 
co/« Wagler, 1830 (Xat. Syst. d. Ampbibien, p. 200, type Bufo alhifrons 

Agricola Bbisius, 1857 (L c, p. 331), was proposed as a subgeneric 
name for 2[icrotus (ig rest is. Tbe differences between tbis sjiecies and 
the albes of M. arvaJis are too sligbt to entitle the groups to rank as 
distinct subgenera; but assuming that it Mere desirable to separate 
them tbe name Agricola would be antedated by Mynomes Kafinesque, 
1817, based on 2Fivrotns pcnnsylninicus, a ibrm whose supersi)ecific 
characters are exactly similar to those of M. agrestis. 

Phaiomys Blyth, 1803 (Journ. Asiat. Soc. Bengal, XXXII, p. 89), is 
the first and only tenable name proposed for tbe subgenus having 
Microtiis hJythi as the type. 

Ochetomys Fitzinger, 1807 (Sitzungsb. K. Akad. Wiss. Wien, LVI, 
June, 1807, p. 47), included the water rats of Euro[)e. It is thus 
equivalent to ArvicoJa Lacepede. 

Fraticola Fatio, 1807 (Les Campagnols du Bassin du Leman, p. 30), 
is a subgenus of Arvicola {=jMicrofus) containing: amphihius { = terres- 
tris), nivalis, arvalis, ratticeps, and campestris {=arvalisF). As all of 
these are species either of AHcrottis Schrank, or Arvicola Lacepede, 
the name Fraticola can not stand. Fraticola is, moreover, preoccupied 
in ornithology. 

Sylvicola Yiitio, 1807 (1. c, p. 03), based on Microtus agrestis is exactly 
equivalent to Agricola Blasius, 1857. The name is preoccupied in ornith- 
ology, entomology, and conchology. 

Terricola Fatio, 1807 (1. c, p. 73), contained Microtus suhterraneus and 
M. savli. The name is, however, preoccupied in conchology by Terricola 
Fleming, 1828. 

Isodelta and Anaptogonia Cope, 1873 (Proc. Am. Philos. Soc, XII, p. 
87), are the tenable names for two extinct subgenera found iu the Post- 
pliocene cave deposits of Pennsylvania. Their types are Microtus 
. speothen and M. hiatidens, respectively. 

Evotomys Coues, 1874 (Proc. Acad. Xat. Sci. Phila., p. 180), is the 
tenable name for the genus of which Mus rutilas is the type. 

Micrurns Forsyth Major, 1870 (Atti della Societa Toscana di Sci. 
Natural!, Ill, fasc. I, p. 120), founded on Mina Palumbo's description of 
Arvicola nehrodensis (a Fityniys), is preoccupied by Micrnra Ehrenberg, 
1831, a genus of Vermes. 

Alticola Blanford, 1881 (Journ. Asiat. Soc. Bengal, L, pt. 2, jj. 93), is 
the only name proposed for the Asiatic subgenus with Microtus stolicz- 
' kanus as type. 

! Eremiomys and Borioilon Polyakoff, 1881 (Mem. Acad. Imp. Sci. St. 
10933— Xo. 12 2 


Peterribourg, XXXIX su})pl., p. 34), based, respectively, on Mns lagurus 
Pallas and Mus torquatns Pallas, are synonyms of Lai/urus Gloger and 
Dicrostonyx Gloger. 

Keofiher True, 1884 (Science, IV, p. 34), was described as a genus 
with iV". alloii, the only known species, as type. Recently it has been 
shown that the characters of the animal are not enough to separate it 
generically from Microtu.s, of which, however, Neofihcr forms a well- 
marked subgenus.^ 

LasioiJodomys Lataste, 1887 (Annali del Mus. Civ. di Storia iSTatuvale 
di Genova, ser. 2a, Vol. IV, p. 208), is a synonym of Phaiomys Blyth, 
1803, the species on which the two names were based, Microtus hrandtl 
Radde and Microtus hJythl Blanford ( = .!/. leucnrus Blyth nee Arvicola 
leucuriis Gerbe), respectively, being in no way separable subgenerically.^ 

Phenacomys Merriam, 1889 (Xorth Am. Fauna, No. 2, p. 28), is the 
tenable name for the genus of which Phenacomys intermedius is the type. 

CampicoJa Schulze, 1890 (Schriften Xaturwiss. Vereins d. llarzes in 
Wernigerode, V, p. 24), is a subgenus formed for the reception of the 
species Microtus arralis, M. suhterrancus, and 31. camjycstris. It is 
thus a compound of two subgenera, Microtus {ari-aUs and campestris) 
and Pitymys {suhtcrraneus), each of which has previously received a 
teuable name. Campicola is, moreover, preoccupied in ornithology 
(Swainson, 1827). 

Bramns Pomel, 1892 (Comptes Eeudus, Paris, CXIV, p. 1159), is 
based on a mandible and the teeth of both jaws of a rodent from the 
Quaternary phosphorites of Trara de Xedroma near Ain-Mefta, Tunis. 
Although the author compares this fossil with the bones and teeth of 
the water rat, he points out such striking differences between the two 
that it is very doubtful whether Bramus can be considered a member 
of the subfamily Microtincc. (See p. 73.) 

Aulacomys Eboads, 1894 (American Naturalist, XXVIII, p. 182), 
although based on an abnormal specimen, is the tenable name for a 
group of American water rats, should tbe latter be considered sub- 
generically distinct from Arvicola. The peculiarities of the original 
si>ecimen of Microtus arvicoloides, the type of Atilacomys, are such that 
the group was originally given full generic rank. 

Mictomys True, 1894 (Proc. U. S. Xat. Museum, XVII, Xo. 999, 
p. 242, Advance Sheet, April 20), was proposed as a full genus with 
Mictomys innuitus True for tlie tyi)e and only known species. The name 
is tenable, but the group is only a subgenus of 8yna})tomys.'^ 

Tetramerodon Rhoads, 1894 (Proc. Acad. Xat. Sci. Phila., p. 282), is 
the most recent synonym of Microtus. The author, as Blasius had 

iTrue, Report of the Smithsoniaa Institution for 1884, Part II, pp. 325-330. PI. II. 
Merriam, North American Fauua, No. 5, p. 60, 1890. Chapman, Bull. Am. Mns. Nat. 
Hist., New York, VI, p. 334, 1894. 

2 See Actes de la Societe Scientifique du Chili, IV, p. CLXXXYIII, 1894. 

3 See Merriam, Proc. Biol. Soc. Washington, X, p. .57, 1896. 

July, 1896.] 



aheatly done nearly forty years before, divides the subgenus Arvicola 
( = Mierotus) into two groups, based on tlie structure of the middle 
upper molar. To the species with this tooth formed of five prisms he 
restricts the name Mynomes, while to those with the same tooth made 
up of only four prisms he applies the new name Tetramerodon. The 
character in question is far too trivial to serve alone as the basis for a 
subgenus. If, however, the advisability of subdividing the genus along 
such narrow lines be admitted, the name Tetramerodon still becomes a 
synonym of Microtus, since ^[. arvalis, the type of the latter, is itself 
a species with the middle upper molar four parted. 


The most important studies of the various groups of Microtina', but 
more especially of the subgenera of Microtis, are those of De Selj^s 
Lougchamps (183G to 1862), Blasius (1857), Baird (1857), Fatio (1867), 
Coues (1874), Blanford (1881), and Lataste (1887). The names used by 
these authors for the subdivisions of Microius adopted iu the present 
classification are shown in the accompanying table: 

Table of Xames used hij ^Infhors for the Suhijenera of Microtus. 

Names used I De Selys | jjlasius, 
111 the i)res- i Longchamps, ,0='- 
ent paper. I 1836 to 1862. | ^''^'• 



Arvicola Memiotomys Palitdicola 

I A rvicola Arvicola 

Micrntus '\ i (part). 

My names .. Agricola .. 


Microtus .. .. Arvicola 
I (part). 

Pedo)iiys. . 

Fatio, Coues, 

1867. ! 1874. 


j Praticola 

Hemioto- \ Sylvicola.. 


Myonovies Xeodon, 

Pitymys .. Terricola.A Pityviys 


Cliilutiis I ' Chilotus 

Lagnrvs ' 

A Iticola 

Ilyiieracrius ' ' 


y>'0 fiber 








Allicola . .. 
A Iticola 

part .-. 
X e don 


De Selys Longchamps imblished two extended papers on the Euro- 
pean Microtinw, and later a note supplementary to the first of these. 
The first paper appeared in 1836 under the title 'Essai Monographique 
sur les Campagnols des environs de Liege.' In this the author showed 
that hitherto the voles had been divided into two groups, according 
to their habits, the aquatic species being separated from those that are 


strictly terrestial. This proved nusatisfactory because tlie two were 
found to intergrade imperceptibly. Heuce he proposed to rearrauge 
tlie si)ecies according to the length of the ears. The first division, or 
that in which the ears are extremely short or apparently absent, he 
named Hemiotomijs, This the author subdivided into two sections, 
neither of wliich he named. The first contained one species, Arvicola 
fulvus {^=Microtns arvalis), distinguished by its short tail and by the 
supposed absence of external ears. The second contained the water 
rat. To Arvicola {=Microtus) proper were referred the three species, 
arvalisj suhferraneus, and rufescens { = Ei'otomys glareolns). Six years 
later, in liis Etudes de Micromammalogie, De Selys Longchamps fol- 
lowed the same system of classification, but considerably extended it 
and included species from Asia and iSTortli America. This later scheme 
is as follows: 

The genus is first divided into two sections, one of which consists of 
species with ears shorter than the fur and with very small eyes, the 
other of species with the ears as long as tlie fur and with tlie eyes well 
developed. The first section contains two groups, (1) Hcmioiomys with 
the European water rats and the American Arvicola riparius {=Microtus 
pemisylvanicus), and (2) Microtus with the species/wZyws, savU, ceconomus, 
and certain American forms not mentioned by name. The second sec- 
tion is divided into three groups: (1) Arvicola with the species suhter- 
ranens, arvalis, gregalis, alliarius, duodecimcostatus, and socialis; (2) 
2[yodes with the two species ruhidus { = Evoiomys (/lareolus) and rntilits 
[z=Evotomys rutilus) ; (3) Mynomes with the species 2}ratrnsis {=:Microti(s 
pennsylimnicus). These groups and sections the author considers in no 
way entitled to rank as genera or subgenera. He names them merely 
for convenience. ^ In a postscript published at the time of distribution 
of the last copies of the Essai Monographique, twenty-six years after 
its appearance, the author makes a few corrections in the classification 
previously adopted. He points out that his Arvicola fulvus is merely 
a young specimen of ^rl. arvalis that by accident had lost its external 
ears, and, furthermore, that the species suhterraucus should be trans- 
ferred to the section Microtus. 

The classification as finally perfected is as follows: 

Genus Arvicola: 

Group Hemiotoimjs (water rats). 
Group Microtus {suhierranens and savii). 
Group Arvicola (typical voles). 
Group Mrjodes (glareolus). 
Group Mynomes (2)eiiusijlca)ticiis). 

' Je dois pr6venir que je m'opposerais entierement a relcvation d'aueune de ces 
sections au raug de genre ou de sous-genre. Toutes passent de I'une a I'autre par 
des nuances inseusibles dans la longueur de la queue et des oreilles; et, quant au 
caractere tiro de la racine des dents, il est probable qu'il existe a uu degrd plus ou 
moins fort chez d'autres espoces. Si je me suis perniis d'imposer a ces gioupes des 
nonis latins pris parmi les synonvmes du genre, ce n'est nullement pour qu'ils puissent 
etre iutroduits dans la nomenclature binaire, mais pour donner anx strangers I'id^e 
des divers noms que j'ai employes en franvais. (Micromammalogie, p. 87.) 


The groups Hemiotomys, 3licroti(S, aiul Arvicola of De Si'lys Loug- 
cliainps are exactly ecjuivalent respectively to tiie subgenera Arvicohi, 
ritymi/s, aud Microtus of the present j)aper, while Myodes is the same 
as the genus Evofomys. The grouj) Mynomes based on Eafiugsque's 
description of Mijiiovics 2}>'f<t('>'''^is { = Microfiis peuHsylvcmicus) sliould be 
united with Arricola (Microtus, as now understood), a course whicli the 
author no doubt would have followed had he been acquainted with the 
type species, 

Blasius published in 1857, in his 'Fauna der AVirbelthiere Deutsche 
lands,' a classitication of the voles based primarily on the pattern of 
enamel folding in the first and second molars of the lower jaw and the 
second molar of the upper jaw. This system differs in many ways from 
that of De Selys Lougchamps, and is as follows: 

Genus Arvicola: 

Subgeims Hypudcvus {{/larcoJiis). 

Subgenus raludicola {amphihius l—terreNfris'\, iiivali'^, ratliceps) 

Subgenus Agricohi {agrestis). 

Subgenus Arvicola : 

A. Arvicola (campestris, arvalis). 

B. Microtus De Selys j)art (subterraneiis, savii). 

The subgenus Arvicola Blasius subdivides into two sections, A. 
Arvicola and B. Microtus De Selys (part). The former includes the 
species campestris and arvalis, the latter suhterraneus and savii. The 
subgenus Hypudwus and the section Microtus are equivalent, resj^ec- 
tively, to the genus Evotomys and the subgenus Titymys of the present 
paper. Of the other groups, the restricted Arvicola contains the tyi)ical 
species of the subgenus Microtus, Agricolay a slightly aberrant form of 
the same, and Paludicola, the subgenus Arvicola and two aberrant 
members of the subgenus Microtus. Blasius's subgenera Faludicola and 
Arvicola are excellent illustrations of the unnatural results of a system 
of classification based on one set of characters. While there is a general 
similarity between the enamel pattern of the three species associated in 
the former, Microtus tcrrestris differs from M, rattice^JS and j\[. nivalis 
in the form of the skull, the number of plantar tubercles, the quality of 
the fur, and in the presence of large musk glands on the sides. In the 
subgenus Arricola Blasius associates two of the most distinct subgenera 
of the genus Microtus {Microtus and Fitymys), and treats the differences 
in the number of mamma' and footpads, form of skull, and size of eyes 
as matters of trifiing importance in comparison with the general simi- 
larity of the enamel pattern. On the other hand, the author recognizes 
Agricola as a full subgenus, when the chief character on which the group 
is based is the presence of a minute supplemental postero-internal prism 
on the middle upper molar. 

The classification adopted by Baird (Mamm, K. Am., 1857) is based 
OH a combination of characters, and is thus much more satisfactory 
than the artificial arrangement published almost simultaneously by 


Blasius. His classification of tlie subdivisious of Microtus is as 

GenusylrricoZrt ; 

Subgenus Hiipnilcvus (t/appcri). 
Subgeiins Arricola (typical voles). 

Section Memiotomys {most of the American species and the Euroj)can 

Section Chilotus (oregoni). 
Section Pedomijs (aimterus). 
Section Pifymys (piuetonim). 

Baird's subgenera Hyjjudwus and Arricola are equivalent to the 
genera Eroiomys and Microtus of tlie present paper, while his sections 
Chilotus, Pedomys, and Pityniys are equal to the subgenera of the same 
names. The section Ilemiotomys of Baird is the Arvicola of De Selys 
Lougcliamps, and the subgenus Microtus of the present paper. 

In 1867 ratio published a classification of the European voles in a 
paper entitled 'Los Cam])agiiols du ]>assin du Leman.' This arrange- 
ment is essentially the same as that of Blasius. Fatio, however, recog- 
nizes Hyimdcvus {■=Erotomys) as a full genus, and raises the second of 
Blasius's two sections of the subgenus Arricola to the rank of a sub- 
genus, while the first he unites with Microtus terrestris, M. nivalis, 
and M. ratticeps to form the subgenus J*raticola. He also arbitrarily 
changes the names of certain groups. His classification is as follows: 

Genus Hypudtvus (ylareolus). 
Genus Arvicohi. 

Subgenus rraticoJa (' nmjiltihins,' nivalis, arralis, ratticeps, campesiris). 

Subgenus Sylricola {ayrestiis). 

Subgenus Tcrricola {siihterrantus, savii). 

The subgenus Tcrricola and the genus Hypudcvus are equal, respec- 
tively, to the subgenus Vitymys and the genus Evotomys of the present 
paper. The subgenus Sylricola is equivalent to the subgenus yl^r/co/fl 
of Blasius, like it containing the x)entamerodont species of the subgenus 
Microtus. The subgenus I'raticola includes the type species of both 
Arvicola and ^licrotns, together with three other tetramerodont species 
of the latter. 

In 1874 Dr. Coues published, in the Proceedings of the Academy of 
Natural Sciences of Philadelphia, an abstract of his monograph of 
the North American Murida^, which appeared in full in Volume XI 
of the Eeport of the United States Geological Survey of the Terri- 
tories (Monographs of North American Eodentia). Here he presented 
a classification of the xVmerioan Microtinw based primarily on Baird's 
review of the group. The differences between the arrangements adopted 
by Baird and Coues are so slight that a few words only are necessary 
in regard to the latter. Dr. Coues recognizes the red-backed mice as a 
distinct genus, which he calls Erotomys, after showing that the name 
Hypuda'us generally used for the group is untenable. The subgenera 
of Jlicrotns adopted by Dr. Coues are exactly equivalent to Baird's 


sections of liis typical subgeuus Arvicola. Dr. Cones points out 
Baird's eri-or in the application of tbe name Eeiniotomys De Sclys 
Longcliamps, and substitutes for tbe latter tbe equally untenable 
Mynomes Eafinesque. 

In 1881 Bbmford proposed, in tbe Journal of tbe Asiatic Society of 
Ben,£;al (Vol. L, Pt. II, pp. 88-117), a classification of tbe voles of tbe 
Hiiiiidayas, Tibet, and Afghanistan. Tbe species occurring- in tbis 
region be arranges in three sections, thus:^ 

Genus Arvicola: 

Section I'ah((HcoIa, {hhjilii, mandrianus). 

Section AUicola (sloliczkaniis, strachci/i, roylei, hlanfordi, ici/nnei}. 

Section Xeodou {.nkkimensis, mdanoyaster). 

Blanford's 'sections' P<//Hf?/cr)/« and Xeodou are excellent instances 
of unnatural classifications based on single characters. Microtus hlythi 
and ^r. mandrianus are species of Fhaiomys, a subgenus which difters 
from the water rats or from Microtus (Microtns) nivalis and 31. (M.) rat- 
ticeps (all of which were included b3' Blasius in Paludicola) in many 
important characters. Because there is a general likeness in the pat- 
tern of enamel folding they are united under one superspecific name. 
Again, Blanford places in the section Neodon the species Microtus siJxl-i- 
>«e»i/.s', which is a slightly abnormal member of tbe subgenus J/ /cro/»s, 
and Microtus mchinogastcr, a species with the bony j^alate formed exactly 
as in the red-backed mice {Evotomys). These members of widely dif- 
ferent groups are brought together on account of a very superficial 
likeness in enamel pattern. Blanford's section Alticola is probably 
equal to the subgenera Alticola and Ryperacrius of the present paper, 
thongh it is still a matter of doubt whether it actually included any 
members of the latter. 

The most recent classification of the subgenera of Microtus is that 
proposed by Lataste. Tbis author has published two important papers 
on the subject, the first in Le Xaturaliste (Tome II, pp. 323, 324, 332- 
334, 342, 343, 347-349, 1883), and the second in the Annali del Museo 
Civico di Storia Xaturale di Genova fSerie 2a, Vol. IV, pp. 259-274, 
1887). While recognizing the unsatisfactory nature of the artificial 
classification adoi)ted by Blasius, Lataste subdivides the voles in 
accordance with a system fully as arbitrary as that followed by any of 
his predecessors. According to Lataste the characters derived from 
tbe teeth of the voles are of no value except in distinguishing between 
genera.2 Tbe subgenera he arranges according to tbe number of maiu- 

' Ijlanford adopted Biasing's classification of the voles at large (pp. 91, 92). Except 
in the case of Paludicola, however, he supposed that none of the European sec- 
tions of the genus Microtus are represented in the region with which he deals. 

""Chez les Eongeurs du uioins, sinon chez tons les Mammiferes, les characteres do 
la denture me serablent d'ordre gcnerique quand ils sont sxiffisamnient nets ct 
tranches, mais sans aucune importance taxouoini(£ue quand ils sont aussi mininies 
que ceux que I'on invoque d'ordinaire, a la suite de Blasius, chez les Campagnols, et 


rnip and plantar tiibeicles. Altbougli tliis system leads to a tolerably 
satisfactory arrangement of tlie European voles, it can not be applied 
to the genns at large, since it would unite sucli distinct groups as 
Arvieohi and Chilotus, or JS/'eoJiher and Piiymys. Lataste's classification 
is as follows : 

Genus Alicrotus: ' 

Siibgeuus Myodes {rtitilus, glareohis). 

Subgenus Microtus (grefjalis, arvaJis, afffesiis, ratiiceps, pennsiilvanicus, nhalia)- 

Subgenus Arvieohi (ierrestris, mnsigiiani). 

Subgenus Pityniys (p'nietorum suliterrmieiis, socialis, middcndorffi). 

Subgenus Lasiopodomys (hrnndti). 

The subgenera Myodes and Lasiopodomys are equal, respectively, to 
tlie genus Evotomys and the subgenus Fhaiomys of the present paper. 
The subgenera Microtus and Arvieohi coincide with groups here recog- 
nized under the same names, while the subgenus Pifymys is essentially 
the same as that defined on page 58. Lataste, however, includes in 
ritymys the species middeiidorffii, which is probably not a member of 
that group as now understood. 


In the discussion of the systems of classification hitherto adopted, 
the impracticability of subdividing the genus Microtus according to 
the variations in any one set of characters has been shown. The 
highly artificial systems of Blasius and Lataste give the best examples 
of the unnatural results to which any such course must inevitably lead. 
In the present paper the classification used is based on an assemblage 
of characters. The more important of these, or the ones least adapted 
to the special needs of the different animals, and hence least likely to 
vary, are: Form of skull, structure of bony palate, pattern of enamel 
folding, number of mamma*, number of plantar tubercles, and presence 
or absence of musk glands on the sides. Characters of less importance, 
because more readily modified to fit a species to the special requirements 
of its environment, and hence more unstable, are: Quality of fur, hair- 
iness of soles, length of tail, form of front feet, size of eyes, and form 
of external ear. It is only through careful consideration of all these 
that a satisfactory arrangement of the species can be obtained. 

Nearly all of the characters now used have been recognized in classi- 
fications already proposed. In every case, however, they have been 
assigned degrees of importance different from those which they now 
receive. To take the three most consi^icuous examples: De Selys 
Loiigchamps arranged the voles with regard to their external form; 

qui portent sur les extr^mit^s mal definies et 6mineniment variables, soit j^osterieur 
d(i la derniore molaire snperieure, eoit anterieur de la prcmii-re molaire inforieure." 
(Ann. del Mus. Civ. di Genova, Ser. 2a, Vol. IV, p. 260 footnote.) 
Compare with this the oiiinion expressed by Biichner. (See footnote, p. 25.) 
' To Lataste is due the credit of recognizing tlie true status of the name MkroUia. 


Blasins based liis classification on the pattern of enamel folding ^itli- 
ont regard to external characters, and Lataste snbdivided the group 
according to the numbers of mammte and plantar tubercles, disregard- 
ing everj^thing else. The impossibility of reaching satisfactory results 
by any of these methods has been pointed out by Biichuer, who, how- 
ever, takes an equally extreme position in his reluctance in any way to 
subdivide the genus Microtus. 

Biichuer was first to recognize the important fact that tlie enamel 
pattern, while variable within certain limits and hence of little value 
taken by itself, is nevertheless of considerable systematic importance 
when considered in connection with other characters.' 

In about 75 per cent of the specimens of a given species the enamel 
pattern conforms to a type which maybe considered normal.^ Among 
the abnormal specimens constituting the remainder, the variation, how- 
ever, is very considerable. In the accompanying illustrations (figs. 1, 
2, 3, 4, o, and 6) are shown some of the conspicuous aberrations in the 
form of the teeth of Microtus pennsylvanicus.^ In the descriptions which 
follow the normal enamel pattern is alone considered. 

1 After meutiouing Lataste's view (see footnote, p. 23), Biichner says: "Meiner 
Ausiclit uach liefert im Gegentheil der Ban der Backenziihue, obwolil derselbe 
zn weileu aucli im Bereiche einer Art leicbt variirt, eiu vorziiglielies Merkmal,. welches 
allein geuommen fiir die Charalvteristik eiuer Art nicht geniigt, iu Yerljiudung aber 
niit (leu iibrigen Merkiualen sebr grosse Dieuste leistet und von bedentendem sys- 
tciuatiscben Wertbe ist." (Wissenschaftlicbe Resultate der von N. M. Przewalski 
nach Ceutral-Asien nuternommenen Reisen. Zool. Theil, Bd. I, Siiugethiere, Lief. 3, 
1889, p. 97.) 

-Among 285 specimens of Microtus pennsylvanicus 71, or 21.9 per cent have tbe 
enamel pattern in some way abnormal. Of these, 26, or 9.1 per cent, have the first 
outer triangle in ia^3 communicating more or less freely with the inner triangle 
(fig. 3); one has the second outer triangle opening into the posterior loop (fig. 3); 
two have the posterior loop of very unusual shape (iig. 3) ; one has a second inner 
closed triangle iu in3 (fig. 3), and 14, or 4.9 per cent, show a distinct fourth salient 
angle on the outer side of the same tooth. In the first lower molar 24, or 8.3 per 
cent, liave 6 closed triangles (fig. 4), one has only 3, still another has 7 (fig.4), 
while in 5, or 1.7per cent, there are 4 (fig.4). Of these 28.5 specimens m 3 is abnormal 
in 44 cases, or 15.4 per cent, iiTl in 31 cases, or 10.8 per cent. C4rouping the abnor- 
mnlities according to their frequency, they may be arranged as follows: 

m_3 has first outer triangle open in 26 cases, or 9.1 per cent. 

m 1 has one additional triangle in 24 cases, or 8.3 per cent. 

in 3 has an additional salient angle on the outer side in 14 cases, or 4 per cent. 

Ill 1 has one less triangle than usual in 5 cases, or 1.7 per cent. 

Ill 3 has the posterior loop of very unusual shape in 2 cases, or 0.7 per cent. 

m 3 has the second outer triangle abnormal in 1 case, or 0.35 per cent. 

Ill 3 has an additional inner triangle in 1 case, or 0.35 2)er cent. 

iiU has two additional closed triangles in 1 case, or 0.35 per cent. 

Ill 1 lias two less closed triangles than usual in 1 case, or 0.35 per cent. 

■* The drawings here reproduced are all from specimens taken iu the eastern and 
central parts of the United States and adjoining British Provinces. They are 
selected from the series of about 170 l)elonging to the United States Department of 



[No. 12. 

Tlie value of the structure of the bony palate as a taxonomic charac- 
ter was first pointed out by Cones,' who, however, considered it of rather 
more importance than it really is. It was at first supposed that the 
bony palate of all the members of the genus Microtus differed in a con- 
stant way from those of Evotomys. Mr. Oldfield Thomas has, however, 
recently described a Microtus {M. chinoisis) 
in which the palate structure of JEvotomys is 
almost exactly reproduced ; and on further 


Fig. 1. — First upper molar 
iu six specimens of J/t- 
crotiis pennsiilvaiiiens. 

Fig. 2.— Second up- 
per molar in .six 
specimens otMicro- 


Fig. 3. — Third ujiper molar iw 
eighteen specimens of Microtus 


study it appears that several well-marked types may be recognized 
among the species of the genus. These forms of jialate furnish char- 
acters of considerable worth iu defining many subgenera. In all, 
several structures remain sufficiently constant to serve as convenient 
landmarks. The anterior portion of the bony palate, or that formed 

exclusively by thepremaxillaries and 
maxillaries, has no special interest, as 
it shows very trifling variations. All 
the characters of importance are de- 
rived from the part lying behind the 
maxillo-palatine suture. This suture 
in the typi' al palate, or that occurring 

Fig. 4. — First lower molar iu 
eighteen specimens of Microtus 

Fig. 5. — Second lower 
molar in foiir speci- 
mens of Microtus penn- 

Pig. 6.— Third lower 
molar in four specimens 
oi Microtus pcimmjlran- 

in true Microius and iu the great majority of species and subgenera 
(lig. 7 A) forms a broad, U -shaped loop, the convexity of which is directed 
forward and whose apex lies about opposite the middle of the second 
molar. From this point the suture on each side sweeps rapidly back- 
ward and outward until, at the level of the anterior edge of the posterior 
molar, practically the whole width of the palate is occupied by the pala- 
tine, and the maxillaries are reduced to a narroAV rim around the edges 
of the alveoli. 

Monogr. N. Am. Rodeiitia, p. 133, 1877. 

July, 180G.] 



I'ntil just before acquiring- its greatest width, the surface of the pal- 
atine is on the same level with the rest of the bony palate, but imme- 
diately on reaching this point it changes abruptly at the sides, more 
gradually iu the median line, to the level of the anterior border of the 
nteri^terygoid fossa, which lies about 0.5 mm. dorsad of the maiu part 
of the bony palate. In the median line the palatiue slopes gently dor- 
socauda<l to the edge of the interpterygoid fossa, a distance usually of 
about 1 mm., but at the sides it l)realis away suddenly, and tlie spaces 
between the median sloping ridge and maxillaries are occuijied by con- 
spicuous pits (fig. 7 A, Lp). The floor of each pit is continuous with 
the backward projection of the palatine, which runs out to join the 

Fig. 7. — Palatal view of skull of MicroHis {Microtis) aivalis (A) and Evotomyg gappeii (B). (x 3). 
i./a., interpterygoid fossa (reference line crosses pterygoid fossa); i.fn., incisive foramen;, 
lateral bridge; Z. r/r., lateral groove ; L^J-, lateral pit; in. r., median ridge; wz., maxillary ; ^jL, ^/Z'., 
palatine; pmx., premaxillary ; lit., pterygoid (reference line crosses jiterygoid fossa); s. in. »•., slop- 
ing portion of median ridge. 

pterygoid of its side (fig. 7 X^pt.). The ventral outline of the inter- 
pterygoid fossa (fig. 7 A, i.fa.) forms three sides of a figure, which is 
nearly a parallelogram, open at one end, the longer axis parallel with 
the main axis of the skull, and the length more than double the width. 
In front and for a short distance at the sides the fossa is limited by the 
palatines (fig. 7 A, j>/',), l)ut the greater i)art of its boundary is formed 
by the pterygoids (fig. 7 X^pt.). The open end lies between the haniu 
lar processes of the pterygoids. Extending back from the incisive for- 
au)iua are two distinct lateral grooves (fig. 7 A, /. </r.), which traverse 
the bony palate longitudinally, leaving between them a ridge which pos- 
teriorly is continuous with the sloping median ridge already described. 
In these grooves open numerous foramina, larger and more crowded 
just in front of the region from which the bony palate slopes away to 


the level of the pterygoids. Tlie median ridge just here widens 
abruptly and sends out on each side a short process, which is met l)y a 
similar one arising from the jjalatine on the op])osite side of the groove 
(fig. 7 A, /. hr.). These processes usually meet and fuse, thus com- 
pletely obliterating the groove, though they are frequently separated 
by a narrow space. In Uvotomys (fig. 7 B) tlie sloi>ing part of the 
median ridge has disappeared, together with the lateral pits, but 
traces of the median ridge (fig. 7 B, m. r.), tlie lateral grooves (fig. 
7 B, /. gr.), and the bridges (fig. 7 B, /. br.) may still be recognized. 

At different times subgeneric weight has been given to the form of 
the external ear, and to the proportional length of the tail to the head 
and body. Neither one, however, is of any value, except in special, 
isolated cases. The form of the ear is essentially the same in all the 
subgenera, though there are slight modifications in length and in the 
development of the valvular fold by which the meatus is closed. 

The relative length of the tail is far too variable to serve as a useful 
diagnostic character. 


The following keys to the genera and subgenera of Mkrothuv are 
wholly artificial and do not bring the groups together according to 
natural affinities. Since analytical keys are of no value except as aids 
in identifying specimens, it is necessary that they should be based on 
characters that may be studied without difficulty in ordinary museum 
material. Such material, however, is usually so imperfect that a single 
key made with reference to one set of characters (as, for instance, the 
form of the bony palate or the number of mammse) might be of little 
use. Hence several keys are here introduced, each based primarily ou 
a special set of structures. Of the tliree keys to the genera, No. 1 is 
made, so far as possible, with reference to the skull alone; No. 2, with 
reference to the teeth, and No. 3, with reference to external characters. 
Of the keys to the subgenera of Microtus^ No. 5 is based primarily on 
characters derived from the structure of the bony i)alate, and is thus 
useless for the identification of specimens the skulls of which are not 
available for stud}'. Key No. G is based on the pattern of enamel fold- 
ing and may be used with specimens having broken skulls. The lines 
in italics inserted in parentheses in this key are for the identification of 
individuals with abnormal enamel patterns. These usually occur in the 
proportion of about one to four (see p. 25). Hence, one fourth of any 
given lot of specimens will agree with the characters given in paren- 
theses-, the great majority, however, with those in heavy type. Key 
No. 7, based primarily on the mammie and footpads, is made almost 
exclusively with reference to external characters. It is necessarily 
incomplete, since the number of mamnuTB and footpads is in several 
instances unknown. It is, of course, impossible to use this key except 
with alcoholic si)ecimens or freshly killed animals. Key No. 8 — if it 


may be called a key — is a rough grouping' of the subgenera of Micrgtus 
according to the essential characters used iu the chissilicatiou here 
adopted. The keys are in all cases based on the characters of adults 


[Based primarily on tlie sliull.l 

Skull of adult more thau 50 mm. loug Fiher 

Skull of adult less than 45 mm. loug. 

Molars rooted; skull always less than 30 mm. long. 

Posterioi' border of j)alate a thin-edged shelf, contiuuous between 

alveoli of posterior molars Evotomys 

Posterior border of palate not forming a shelf Phenacomys 

Molars rootless; skiiU often more than 30 uuii. long. 

Middle part of zygoma expanded so as to form an oblique 

plate about 4 mm. broad Leminus 

Middle part of zygoma only slightly expanded. 

Rostrum about \ total length of skull Synajitomys 

Eostrum more thau ^ total length of skull. 

Postorbital process of squamosal peg-like Dicrostonyx 

Postorbital process of squamosal shelf-like Microlua 


[Based priniarily on tlu- teeth.] 

Length of maxillary tooth row in adult more than 14 mm Fiher 

Length of maxillary tooth row iu adult less than 13 mm. 

Roots of lower incisors or inner (liugual) side of molar roots. 

Upper iueisors grooved Synaptomys 

Upper incisors not grooped. 

m 1 with 3 closed triangles Lemmus 

m 1 with 7 closed triangles Dicrostonyx 

Roots of lower incisors on outer side of molar roots, 
^lolars rooted. 

Teeth weak; triangles tending to remaiu open; salient angles 

rounded Evotomys 

Teeth strong; triangles (dosed; salient angles sharp Phenacomys 

Molars rootless Microtus 


[Based primarily ou external characters.] 
Tail tlattened laterally Fiber 

Tail terete. 

Tail shorter than hind foot. 

Thumb with strap-shaped nail Lemmus 

Thumb without strap-shaped uail. 

External ear rudimentary Dicrostonyx 

External ear well developed Microtus (Asiatic species 

of subgenus Laynrits) 
Tail longer thau hind foot. 

Upper incisors grooved Synaptomys 

Ujiper incisors not grooved. 

Color usually reddish; molars weak, with triangles tending 

to remain opeu and with salient angles rounded Erotomys 

Color brownish, grayish, or yellowish; very seldom reddish; 
molars strong, with closed triangles and sharp salient angles. 

Molars rooted Phenacomys 

Molars rootless Microtiia 



Miuulibnlar molars with closed triangles on outer side Synaptomys 

Mandibular molars without closed triangles on outer side Mictomys 


[Based primarily on the bony palate.] 

Palate normal or nearly so (see p. 27). 

Third lower molar with all triangles closed.. La(jnrns 

Third lower molar normally without closed triangles. 
Claws small, those on front feet always .'ihortest. 

Plantar tubercles 6 - Micrntus 

Plantar tubercles 5. 

Tail more than 30 per cent of total length it-rirola 

Tail less than 30 per cent of total length. 

nTl with 5 closed triangles Cliilotus 

inl with 3 closed triangles Pedomys 

Claws large, those on front feet usually longest. 

Fur long and soft Fhaiomys 

Fur dense and nude-like ntymys 

Palate highly abnormal. 

Palate ending in a broad median plate cut off from maxillaries at the sides. 

Third lower molar with all triangles clo.sed Neofiher 

Third lower molar without closed triangles. 

Skull flat ; andital bulhe small Hyperacriits 

Skull high ; audital bulla} large Jlticola 

Posterior border of palate continuous between maxillaries. 

Posterior border of palate straight Fothenomys 

Posterior border of palate with median projection JvicUomys 


[Based iirimarily on tlie t(*th.] 
{m 1 with 6 or 7 closed irianglcn.) 
{Plantar tiihcreles 5.) 

(Small ; not aquatic ; fur short Cirilotns) 

{Large ; aquatic ; fur long -^ rricola) 

{Plantar tnbercles 6 Jlicrotus) 

m i with 5 closed triangles. 

m 3 with 3 closed triangles. 

m 3 with triangles always closeu Neofiber 

m 3 with triangles normally open. 
Plantar tubercles 6. 

Fur not specially modified, claws moderate. 

Posterior loop of m 3 short cr strongly curved; palate normal. Microtus 
{Posterior loop of m 3 long and straight : palate ahnormal.) 

{Skull hroad and flat ; plantar tubercles -T Eyperacrins) 

{Skull not broad and flat ; plantar tubercles 6 Jlticola) 

{Fur rcry long and soft, aspect lemming-like, claws rery long. Phaiomys) 
{Plantar tnbercles 5.) 

{Small ; not aquatic : fur short -. Chilotns) 

{Large ; aquatic ; fur long Jrricola) 

' Characters in heavy-faced type are those of specimens with normal enamel pat 
tern; characters in italics (inserted in parentheses) are those of specimens with 
abnormal enamel pattern. 

July, 189b-.] KEYS TO SUBGENERA. 31 

m 3 with 2 closed triangles. 

Triangles in m 3 alternate and closed. 

Aquatic ; soles naked ; tail long Neofiber 

Not aquatic ; soles hairy ; tail short Lagurus 

Triangles in m 3 normally opposite and open. 

Claws small, those on hind feet always longest. 
Mammffi 8 ; foot pads 5. 

Small ; not aquatic ; fur short Chilotus . 

{Large; aquatic; fur Ion;/ Jrvivola) 

{Mamma 4; foot pads 5; sk>iU liir/h Pedomys) 

{Claws large, those on front feet of lev longest.) 

{ Fur short and dense J'itjjmys) 

( Fur long and soft I'haiomys) 

m 1 with 4 closed triangles. 

m 3 with posterior loop elongated in axis of jaw. 

Skull broad and fiat ; plantar tubercles 5 Hyperacrius 

Skull not broad and flat ; plantar tubercles 6 Alticola 

(m 3 with posterior loop rounded or crescentiv. } 

{m 3 with 3 closed triangles ^ficrotus) 

(m 3 irith 2 closed triangles Jrricola) 

m 1 with 3 closed triangles. 

(m 3 with 3 closed triangles.) 
{Plantar tubercles 6.) 

{Posterior loop of m 3 .^hort or stronghj citrred: palate normal . . . Microtus) 

{Posterior loop of m 3 long and straight: palate ahnormal Alticola) 

{Plantar tubercles 5.) 

{Mamnue S; palate normal Arvicola) 

{Mam mce 4; p)alate abnormal Hyperacrius) 

m 3 with 2 closed triangles. 

Sole almost naked Arvicola 

Sole hairy. 

(Palate abnormal Hyperacrius) 

Palate normal. 

Claws long, all about equal in length Phaiomys 

Claws short, those on front feet shortest Pedomys 

(m S with 1 closed triangle Hyperacrius) 

m 1 with closed triangles. 

m 2 and m 3 of approximately the same form Eothenomys 

m 2 and m 3 very different in form Anteliomys 

[Based prim.irily on inamiiiie ami foot pads.] 

^lanmia' 10 Phaiomys 

Mamma' 8. 

Plantar tubercles 6. 

Palate normal Microtus 

Palate abnormal A Iticola 

Plantar tubercles 5. 

Conspicuous musk glands on sides Arricola 

No musk glands on sides. 

Color dark brown Chilotus 

Color light grayish or yellowish Lagurus 


Maiuiu;e 4. 

Size very large - - - Xiojiber 

Size medium or smal'. 

Plantar tubercles 6 AnteUomija 

Plantar tubercles 5. 

Skull not flattened I'edonuis 

Skull flattened. 

Palai e normal I'Hymija 

Palate abnormal Hijjicracrins 


Palate normal. — Microtus, Pedomys, Pltymys, ChUotus, Phaiomys, Ai-vicola, Lagunts. 

Palate abnormal. — Xeojiher, JUirola, Hyperacrius, Eoihenomys, Anteliomys. 

Third lower molar always with closed triangles. — Neofiher, Lagurus. 

Third lower molar normally without closed triangles. — Microtus, Pedomys, Pitymys, 
ChUotus, Phaiomys, Arvicola, Eothenomys, Anteliomys, Alticola, Hyperacrius. 

First lower molar normally with 5 closed triangles and 9salieut augles. — Microtus, 
ChUotus, Xeojiher, Lagurus. 

First lower molar normally with 3 or 4 closed triangles and 9 salient iingles — 
Pedomys, Pitymys, Phaiomys, Alticola, Hyperacrius. 

First lower molar normally with 3 closed triangles and 7 salient angles. — Arvicola. 

First lower molar without closed triangles. — Anteliomys, Eothenomys. 

Third upper molar normally with 3 closed triangles and 7 to 8 salient angles. — 

Third upper molar normally with 2 closed triangles and 6 salient angles. — Xeojiher, 
Arvicola, Pitymys, Pedomys, Phaiomys, ChUotus. 

Third upper molar without closed triangles. — Anteliomys, Eothenomys. 

Mammic 10. — Phaiomys. 

Mammse 8. — Arvicola, Microtus, Alticola, ChUotus, Lagurus. 

Mamm;e 4. — Xeojiher, Pitymys, Pedomys, Anteliomys, Hyperacrius. 

Plantar tubercles 6. — Microtus, Phaiomys, Anteliomys, Alticola. 

Plantar tubercles 5. — Xeojiher, Arvicola, Pitymys, Pedomys, ChUotus, Lagurus, Hyper- 


Genus SYNAPTOMYS Baird. 
Synaptomys Baird, Mamm. N. Am., p. 558, 1857. Type Synapiomys cooperi Baird. 

Geographic (listrihiition ofty^ye species. — Boreal, Transition, and north- 
ern edge of Upper Anstral Zone in eastern Kortli America from the 
Atlantic coast to Minnesota. 

Geographic (listribution of genus. — jSTortli America from northern edge 
of Lower Austral Zone northward. 

Essential characters : 

Upper incisors with distinct longitudinal grooves. 

Lower incisors with roots on inner (lingualj side of molars. 

Molars rootless. 

Enamel pattern characterized by great depth of reentrant angles en outer side 
of maxillary teeth and on inner side of mandibular teeth. 

m 1 with three closed triangles and two transverse loops, or with four trans- 
verse loops and no closed triangles. 

m 3 with four transverse loops and no closed triangles. 

Feet not specially modified. 

Soles and palms with well-developed tubercles. 

Thumb with large flattened ligulate nail. 

Tail very slightly longer than hind foot, terete. 

External ear well developed. 

July, 1896.] GENUS SYNAPTOMYS. 33 

Skull. — The skull of Si/najjtomy.s (fig. 9 and PL I, figs. 12, 13) is moder- 
ately broad, flat, aud massive, much less so than iu the other Lemmi. 
Eostrum short (nasal bones about one-fourth occipito-nasal length) and 
strougly deflexed; zygomatic arches not broadly flaring as iu Lemmus 
and Dicrostonyx,^ though more so than in the voles; middle portion of 
zygoma very slightly expanded, the outer surface nearly vertical; brain 
case not greatly broadened or flattened, and seldom if ever conspicu- 
ously ridged or furrowed; interparietal with rounded corners, the 
antero-posterior diameter more than half the transverse diameter; 
pterygoids short; interpterygoid fossa about one-sixth basilar length 
of skull; posterior border of bony palate ending nearly as in typical 
Microtus. (See p. 2G, PI. II, fig. 5, and fig. 7, p. 27.) Front edge of 
squamosal forming a narrow, shelf-like postorbital process. 

Teeth. — Anterior faces of upper incisors with distinct longitudinal 
grooves. Lower incisor terminating posteriorly a little in front of the 
hinder edge of the back molar. Throughout its length each mandibu- 
lar incisor lies wholly on the inner (lingual) side of the molar series. 
(PI. Ill, fig. 1.) 

The molars are all rootless. The upper molar series is about one-third 
the basilar length of skull, the lower series slightly less. The enamel 
pattern (figs. S and 10) is characterized by the great depth of the outer 
reentrant angles in the maxillary teeth and of the inner reentrant 
angles in the mandibular teeth. Of the maxillary teeth m 1 and m 2 
show no important peculiarities of form except that the outer reentrant 
angles cut across to the enamel of the extreme inner side, a feature 
shared by Lemmus alone. The posterior upi)er molar, however, like 
that of Lemmus, differs widely from the corresponding tooth in all other 
Microtina'. It is formed of four transverse loops. The first and second 
of these loops are isolated by two deep reentrant angles on the outer 
side of the tooth, while the third is formed by an equally deep dein-es- 
sion on the inner side. The reentrant angles and closed triangles on 
the inner side of the mandibular molars are greatly developed at the 
expense of those on the outer side. In the subgenus Mictomijs the lat- 
ter wholly disappear except in the last tooth. This has a reentrant 
angle near the middle, but no closed triangle. 

External form. — In general appearance Synaptomys resembles the 
Microti much more closely than it does the Lemmi, a fact which has 
given rise to the rather inappropriate names 'lemming- vole' and 'false 
lemming.' The species of Synaptomys are thick-set microtines with 
large heads, ears that just appear above the moderately long fur, short 
tails, aud small feet. In color they are all dull brownish, darker on the 
back, paler on the belly. The palms and soles are tuberculate, as in 
the voles. 

General reniarks.— Synaptomys differs from all the other genera of 

'Tlip ratio of zygomatic breadth to basilar l<'njj;th is approximately 70 in SynaptomySy 
75 iu Lemmus aud Dicrostonijx, and 65 iu Microtus. 
16933— No. 12 3 


Microthuc in its grooved incisors. From tlie other leniniiiig'S it may be 
known by its numodified external form, and from the A'oles by the 
characters of its molars. 

Subgeuns SYNAPTOMYS Baird. 
Sijna2)tomi/s Baird, Mamm. X. Am., p. 558, 1857. Type Si/napiomiis cooperi ]5aird. 

Geo(/rapMc distribution of type species. — Boreal, Transition, and north- 
ernmost edge of Austral zone in eastern United States and adjoining 
British Provinces; west to Minnesota, south to Iowa, Indiana, Ohio, 
and Maryland. 

Geograpliic distribution of subgeuns. — Boreal zone to northern edge of 
Lower Austral zone in eastern Canada and eastern United States; 
west to Minnesota, south to Kansas and Virginia. 

Essential cliaractcrs : 

Eostrum very heavy. 

Palate nearly as in trne Microtus. 

Mandibular molars Avith closed triangles on outer side 

Mamm* 6. 

Sl-uU. — The skull of true ^Synaptomys (flg. 9 and PI. I, flg. 13) differs 
from that of Mictomys in the remarkably heav^^ rostrum and in certain 
slight details in the form of the bony palate. The latter is almost 
exactly as in typical Microtus, the slight peculiarities in form being 
well within the limits of variation in the latter. 

Teeth. — The incisors in true Synaptomys are, like the rostrum, exces- 
sively strongly built. The grooves are usu- 
ally sharply defined and placed near the 
outer edges of the teeth. 

The maxillarj^ teeth differ in no way from 
those of the species of Mictomys. In the 
Fig. 8.-Enamei pattern of molar molars of the lowcr jaw, howevcr, the outer 

teeth of Synaptomys cooperi. (s 5.) ^ „ ■,,,■,'• , i 1 

edge of each tooth is cut by a deep reen- 
trant angle which isolates a large outer triangle (fig. 8). 

Mammw. — The nitmber of mamm;e in Synaptomys has been variously 
recorded as four and six. Dr. Cones, in his monograi)h of the American 
Microtinw, states that he finds six, four pectoral and two inguinal, in a 
female from Brookville, Ind.' Quick and Butler,^ however, noted only 
four, two pectoral and two inguinal, in specimens from the same local- 
ity. Mr. Vernon Bailey records six mammae in a female collected for 
the United States Department of Agriculture at Ann Arbor, Mich., 
and I find the same number in an alcoholic specimen taken at Eogerfe- 
ville, Tenn. It is probable that six is the normal number, and that 
Quick and Butler overlooked the ]»osterior pair on the breast, as these 
are smaller than the others, at least in the alcoholic specimen from 

1 Monogr. N. Am. Rodentia. p. 236. 

2 American Naturalist, XIX, p. 114. 

July, 1896.] 



General remarlxS. — The characters distiugiiishing- the subgenera Syn- 
aiitomys and Mictomys are discussed under the latter. 

Three species of true Synapiomys are now known: *S'. cooperi Baird, 
S.fatuHs Bangs, and *S'. hdaletes Merriam.^ 

Subgenus MICTOMYS True. 

1894. Alictomtjs True, Proc. U. S. Nat. Mus., XVII, No. 999, p. 242. Advance sheet, 
April 26, 1894 (full genus). Type Mictomj/s inriuitus True. 

1896. Mictomys Merriam, Proc. Biol. Soc. Washington, X, p. 57, March 19, 1896 

Geographic distribution of type species. — Synaptomys inmiitus is known 
from the type locality only, Fort Chimo, Ungava, Labrador. 

Geographic distribution of subgenus. — Hudsonian zone from Labrador 
to Alaska, south to northern California. 

Essential characters : 

Eostrum slender. 

Palate not as in true Miciotus. 

Mandibular molars without closed triangles ou outer side. 

Mammte 8. 

Slcull. — The skull of Mictomys is in general much like that of Synap- 
tomys proper, but the whole rostral part (including incisors) is dispro- 
portionally slender and weak 
(fig. 9, and PI. I, fig. 12). The 
bony palate is formed on the same 
plan as that of true Synaptomys 
or of Microtus i^roper, but differs 
from both of these in the prolon- 
gation of the median ridge as a 
spine projecting into the inter- 
pterygoid fossa. 

The i^terygoids are usually 
longer and more slender than in 
Synaptomys, and the hamular i^ro- 
cesses less strongly bent outward. 

Teeth. — The incisors in Mictomys are much smaller in proportion to 
the size of the skull than in the subgenus Synaptomys. The grooves 
in the upper incisors are usually nearer the middle of the tooth, and 
less well defined than in true Syna2)tomys. 

The maxillary teeth (fig. 10) are exactly as in the subgenus Synap- 
tomys. The lower molars, however, difter from those of true Synaptomys 
in the absence of reentrant angles on the outer borders of all but the 
hindermost. Even in this the reentrant angle is never deep enough to 
isolate an outer triangle. 

Mamma\ — In the type of Synaptomys innuitus there are eight mammse, 
two more than have been recorded in Synaptomys i^roper. ^Yhether 

Fig. 9. — a. Hitnaptoiiiys helaleteg; b. Si/Haptomys 

See Merriam, Proc. Biol. Soc. Washington, X, p. 57, 1896. 


tliis difference is constant or otherwise, it is, liowever, impossible to 


General remarlxS. — Mictomys was lirst described as a full genus, but 
tbe characters ou which it rests are of no more 
than subgeueric importance. The group is 
distinguished from true Syna;ptomys by the 
slender rostrum and incisors, slightly different 
form of bony palate, creuulate outer border of 

Fig. 10— Enamel pattern of lower molars, and probably by the number of 

molar ic.ih Synaptomys in- ^^.^^^^^^^ ^^^^^ 
nmtus. (x5.) 

Four species of Mictomys have thus far been 
described, Synaptomys innnitns (True), ^S. wravgeli Merriam, /S'. dalli 
Merriam, and S. truei Merriam.^ 

Genus LEMMCS Link. 

1795. Lemmus Link, Zool. Beytriige, I, Pt. II, ]). 75, 1795. Type by elimination Mas 

lenunus Liuu. 
1811. Ml/odes Pallas, Zoogr. Rosso- Asiat., I, p. 172, 1811 (part). 
1877. Ml/odes Cones, Mouogr. N. Am. Rodentia, p. 237, 1877, anil most subseijuent 


Geographic distribution of type species. — Arctic region in Asia and 
eastern Europe. 

Geographic distribution of genus. — Arctic region in both hemis- 

Essential characters : 

Upper incisors without grooves. 

Lower incisors with roots on inner (lingual) side of molars. 

Molars rootless. 

Enamel pattern as in tSijnajytomys. 

Feet highly modified. 

Palms and soles without well-developed tubercles. 

Thumb witli large flattened ' strap-shaped ' nail. 

Tail shorter than hind foot, terete. 

External ear small but well developed. 

SI-hU. — The skull of Lemmus (PI, I, tig. G) is perhaps the most highly 
modified in the family Microtina\ The rostrum, like that of Synapto- 
mys^ is short in proportion to the length of the skull (nasal bones con- 
tained about three and one-half times in occipito-nasal length), the 
dorsal profile bent abruptly downward. Zygomatic arches very ab- 
ruptly and broadly tlaring, each expanded near the middle into a wide, 
strongly oblique plate.^ Brain case broad, flat, and subquadrate iu 
outline, but dwarfed in appearance by contrast with the large zygomata. 
Pterygoids short (about as iu Synaptomys). 13ony i)alate terminating 
essentially as in Synaptomys, but lateral pits very deep and anterior 

' See Merriam, Proc. Biol. Soc. Washington, X, p. 61, 1896. 
^ These plates may be nearly 5 mm. across iu the widest part. 

Jl-LY, 1896.] 



Fig. 11.— Enamel pattern of molar 
teeth, Lemmus leinmus. (x5.) 

edgeof interpterygoicl fossa carried forward over (dorsad to) overliang- 
iiig edge of palate (PI. 11, fig. 14). The anterior edge of the squamosal 
forms a narrow but distinct shelf-like postorbital process, much as in 
Synaptomys^ but more strongly developed. 

Teeth. — The dentition of Lemmus is essentially the same as that of 
Synaptomys. The upper incisors are, however, much more slender in 
proportion to the size of the skull, and are without the peculiar grooves 
always present in Synapiomys. In the pattern of enamel folding, the 
only difference between the two genera is that the third transverse loop 
in the hindermost maxillary tooth is iso- 
lated by a single reentrant angle in l>iynap- 
iomys, and by the contact of two reentrant 
angles in Lemmus (fig. 11). 

External form. — In external form the 
species of Ljemmus diflter very widely from 
all other microtiues except Dicrostonyx. 
The head is disproportionately large for 

the short thick body,^ while the tail is reduced to a mere rudiment only 
about two-thirds as long as the hind foot. The feet are highly modified 
to fit the animals to their fossorial habits. While the hind feet are 
unusually large and strong, the front feet are even more specialized. 
The thumb is provided with a large ligulate nail and the fingers are 
armed with long, sharp claws (fig. 12). The claws are, however, sim- 
ple in form and are not subject to the periodic changes that occur in 
those of Dicrostonyx. 
In the alcoholic specimens that I have examined the palms show no 
trace of tubercles, but the soles bear indications of sev- 
eral very small and exceedingly rudimentary pads close 
to the base of the toes. The fur is remarkably long and 
dense, the palms and soles densely furred, and the tail 
provided with a pencil of stiff bristle-like hairs longer 
than the tail vertebrie. 

General remarls. — The species of Lemmus are true 
lemmings with highly modified skull and external form. 
With these characters they combine the dentition of 
Synaptomys without, however, the peculiar incisors of 
the latter. Ljemmus difiers from Synaptomys in its highly 
modified skull and external form as well as in the dental character just 
mentioned. From Dk-rostonyx it is distinguished by cranial and dental 
characters and by the well-developed external ears (fig. 15), as well as 
by the simple claws and large thumb nail. 

The species of Lemmus at present recognized are L. lemmus (Lin- 
iiieus), Tj. ohensis (Brants), L. sehistieolor (Lilljeborg), and L. niqripes 

Fig. 12.— Left front 
foot, Lemmus 
li'mmux (hair re- 

This peculiarity is carried even further iu Lemmus than in Synaptomys. 


Genus DICROSTONYX Gloger. 

1830. Cuniculus Wagler, Nat. Syst. d. Amphibien, p. 31, 1830 (part). 
1877. Cuniculus Cones, Moiiogr. X. Am. Rodeutia, p. 243, 1877. 

1841. Dicroxioniix Gloger, Gemeinn. Hand- u. Hilfsbucli d. Naturgesch., pp. XXXI, 97, 
1841. Type, an American species, probably Mus hudsonius Pall. 

1854. " MyoJemmus Pomel, Ann. Sci. Soc. Auvergne, 1854 " (fide Trouessart). 

1855. Misothermus Hensel, Zeitscbr. der Deutsch. geolog. Gesellscb., VII, p. 492, 1855. 

Type Myodes forquatus Pall. 
1881. Borioikon Polyakoff, Mem. Acad. Imp. Sci. St. Petersbourg, XXXIX, snppl. p. 34, 
1881. Type Jlyodex torquatus Pall. 

Geographic distribution of type species. — Arctic America. 
Geographic distribution, of genus. — Arctic region in both liemisplieres. 
Essential characters: 

Upxier incisors without grooves. 

Lower incisors with roots on inner (lingual) side of molars. 

Molars rootless. 

Enamel pattern characterized by approximate equality of reentrant angles. 

m 1 with 7 closed triangles and 2 transverse loops. 

m 3 with 3 or 4 closed triangles and 2 transverse loops. 

Feet highly modified. 

Palms smooth; soles with rudimentary tubercles. 

Thumb with a rudimentary nail. 

Tail shorter than hind foot, terete. 

External ear rudimentary. 

STciill. — The skull of Dicrostonyx (PI. I, fig. 14) in a general way 
resembles that of Lemmus, but is smaller and more lightly built. The 
zygomata are less broadly flaring and the expansion uear the middle is 
comparatively slight. The outer face of the expanded portion, as in 
Lemmus, is strongly oblique. The rostrum is also lighter and more 
slender. While the pterygoids are proportionally longer than in Lem- 
mus, the posterior edge of the bony palate is formed exactly as in the 
latter (PI. II, figs. 12 and 14), The anterior edge of the squamosal 
gives off a conspicuous peg-shaped postorbital 
process very different from the postorbital ])r()C- 
ess in Lemmus or any of the other Microtinc:. 
These pegs are especially conspicuous when the 
skull is viewed from the ventral aspect. 
Fig. i3.-Enamei pattern of Tccth. — lucisors csseutially as in Lemmus. 
molar teeth, Dicrostoni/x from ]\iolars Tootlcss. Pattern of cuamel folding ( lig. 

Uugava, Labrador. (x5.) ^ ^, -, . m, , r. .-• . ^ • -, <• i i j-i 

13) very different from that of either of the other 
genera of Lemmi and in some respects resembling that of the Jlicroti. 
The reentrant angles on the opposite sides of the teeth are approxi- 
mately equal in depth,«thus producing closed triangles of nearly the 
same size on the two sides. The first lower molar contains seven closed 
triangles in addition to a transverse loop at each end. The second 
lower molar contains a posterior loop followed by four alternating 
closed triangles and an anterior transverse loop, which is much flattened 

JCLY, 1896.] 





Fig. 14. — Ear, (a) Dicrostonyx, (b) Lemmus 
(double natural size' 

aud so small that the tips of the salient angles do not reach to the level 
of the tips of tlie other salient angles of the tooth. Occasionally the 
anterior outer triangle opens into the transverse loop. The posterior 
lower molar has a posterior transverse loop followed by three large 
closed or nearly closed triangles (two on the inner side), and a fourth 
smaller triangle on the outer side.' The maxillary teeth have each a 
large anterior loop. This is followed in the first hy five alternating 
closed triangles and a small postero- 
external loop, in the second by four ^,^;Sxt>. a. 
closed triangles and a small postero- 
external loop, and in the third by fonr 
closed triangles and a small ronnded 
terminal loop. 

External form. — In external form the 
species of Dicrostonyx are even more 
specialized than the members of the 
genus Lemmus. As in the latter, the 
head is very large, the tail is reduced to 
a stub, shorter than the hind foot, and 
the feet are highly modified for digging. 
The external ears are, however, mere naked folds of integument lying 
just behind the meatus (fig. 14 a). The fur is long and dense, much as in 
Lemmus. The palms and soles are densely furred, and the tail is pro- 
vided with a stiff pencil of bristle-like hairs, longer than the tail vertebrae. 
The hind feet are very broad, the breadth at base of toes being about 
one-half length of foot.- On the hind foot there are several minute, 
faintly developed tubercles near the base of the toes. The palms are^ 

however, perfectly smooth. The claws on 
the hind feet are large and well formed, 
though in no way different from those of 
Lem rims. Those on the front feet are very 
highly modified, and present seasonal 
changes in size and form unknown else- 
where among the 2licrotiniv. The thumb 
(fig. 15) is greatly reduced in size. The 
thumb nail is so small as readily to escape 
notice, but the ball of the thumb projects 
as a distinct tubercle, the surface of which 
is covered with a thick layer of corneous tissue. The claws on the 
second and fifth fingers are large, though not peculiar in form. The 
two middle claws, on the contrary, while in summer not different 
from those of Lemmus, are in winter very greatly enlarged (fig. 15), and 

'lu IJicrostoiiyj- torquatus there is a niiiuite supplemental anterior internal loop 
wbich is absent in the species that occurs in Labrador. 
-In Lemmus this breadth is only about one-third length of foot. 

Fig. 15. — Left front foot of three speci- 
mens of Z)icro*<o)ii/a; from Alaska, show- 
ing successive stages in the develop- 
ment of the claws (hair removed). 


wliollj' unlike those of any other microtiue. Dr. Coues's description 
of tlie claws of Bicrostonyx is so interesting that it may be quoted 
almost entire. He says (Monogr. IsT. Am. Eodentia, pp. 248, 240) : 

The two middle fore claws attain their maximum of development iu winter. In 
spring and early summer these claws do not appear very different from those of 
Mijodi's [= Lemmus'], though averaging larger, more bulbous at base underneath, with 
the terminal portion slenderer, straighter, and sharper. This bulbous portion under- 
neath grows out simultaneously with increase in length and amount of curvature of 
the main jiortion of the claw, until it equals or even exceeds the length of the latter, 
and is quite as stout, or even stouter, being somewhat broad and pad-like. At this 
period it runs the whole length of the claw, from which it is separated by a groove 
along the sides, and by a notch at the end, both of varying depth. The claw then 
looks nearly like two claws, one underneath the other. The pad woubl then seem to 
gradually sever its connection with the main claw by progressive increase iu depth 
of the constriction marked by the lateral groove and terminal notch, as well as by 
loosening from the base, when it appears like an excrescence ; it is finally lost. Thus 
the process appears to be a jieriodical one, like the shedding of the horns of rumi- 
nants, and not continually progressive with age; and would seem to be connected 
with the particularly fossorial habits of the quasi-hibernating animal that digs gal- 
l,eries under ground in which to reside during the cold season, as compared with its 
freer and more active mode of life in summer. At the period of the maximum 
development of the claws these equal or surpass half an inch in length. » * # 

General remarls. — Divrostonyx is so readily distinguished by its 
peculiar dentition, highly modiiied feet, and rudimentary external ears, 
that it requires no detailed comparison with any other genus. 

While Dicrostonyx torquatus (Pallas) is the only species now recog- 
nized, there are doubtless several others. 

Genus PHENACOMYS Merriam. 
1889. Phenacomi/s Merriam, North Ameijican Fauna No. 2, p. 28, October 30, 1889. 

GeograijliiG distribution of type species. — Phenacomys intermedins is 
known only from the type locality, Kamloops, British Columbia. 

Geographic distribution of genus. — Boreal North America; also 
recorded from the bone breccia of Ber.emend, southern Hungary, and 
the Forest Beds of Norfolk and Suffolk, England (Nehring, Naturwis- 
senschaftliche Wochenschrift, Xr. 28, ]). 346, July 15, 1894.)^ 

Essentia I cha ra cters : 

Upper incisors without grooves. 

Lower incisors with roots on outer side of molars. 

Molars rooted. 

Enamel pattern characterized by approximate equality of reentrant angles in 
maxillary teeth and great depth of reentrant angles on inner side of mandibular 

m 1 "with five closed triangles. 

m3 with two or three closed triangles, 

' I have not seen the original description of the remains from Beremend (described 
by Nehring in Naturwissenschaftliche Wochenschrift, 1883). The teeth from the For- 
est Beds represent an animal which is certainly not Phenacomys. (Seenoteou JrricoZa 
iniermcdiKS Newton ou page T.o.) 

Jtn-r, 1896.] 



Fig. 16. — Side view of molars, 
Phenacomijs. (a) young, (6) 
adult. (x3.) 

Bony i)alate not terminating in a tliin-edged sbelf continuous between alveoli 
of posterior incisors. 
Feet not specially modified. 
Thumb with a small pointed nail. 
Tail longer than hind foot, terete. 
Fur not specially modified. 

Sl-nJl. — The skull of rhenaeomys (PI. I, fig-. 5) dififer.s very slightly in 
general form from tlmt of typical Microtus. The brain case is, how- 
ever, flatter and more quadrate (but no more 
so than in the subgenera X^(;r/?(r».s' iindl'iti/iuys), 
and the zygomata bend down somewhat more 
abruptly in front. The expansion of the zygo- 
ma at the region of contact between the malar 
and the zygomatic process of the maxillary is 
rather more abrupt than is usual in MicroUis, 
but the difference is very trifling. The postor- 
bital processes of the squamosals are slightly 
more prominent and angular than in il//c>-o/*^s 
arvalis or M.])ennsylvaniciis,hut scarcely more 
developed than in 71/. agrestis, and consider- 
ably less so than in M. alien i. The audital 
bullne are proportionally about the same size 
as or slightly smaller than in Microtus arvalis. 
They are more globular and less ' subfusiform ' 
than in the typical species of true Microtus, but closely resemble those 
of M. agrestis. The palate (PI. II, fig. 1) is formed essentially as in the 
members of the subgenus Lagurus (PI. II, figs. 3 and 4). 

Teeth. — The teeth of Phenaconiys differ in many ways from those of 
the other voles. In young individuals the molars (fig. 10) are rootless, 
but by the time the animals are full grown each molar has developed 
two distinct roots, which, however, remain open until an advanced age, 
though not so long as in the genus Evotomys. 
The pattern of enamel folding (fig. 17) is essen- 
tially the same as that of the voles of the sub- 
genera Fedomys and Fhaiomys. (See pp. 50 and 
57.) The differences are to be found in the lower 
molars where the reentrant angles on the inner 
side are proportionally deeper and those on the 
outer side proportionally shallower than in Ted- 
omys. There is a corresponding difference in the size of the closed 
triangles on the opjiosite sides of the teeth. The anterior outer loop 
in the second lower molar is especially reduced. 

In PItenacomys the root of the lower incisor runs back between the 
roots of the second and third molars, and terminates on the outer side 
of the tooth row in the ascending ramus of the jaw, at about the level of 
the middle of the posterior molar, and distinctly below the dental fora- 
men, (PI. Ill, fig. 2.) While exactly this condition is not found else- 
where except in Evotomys, it is somewhat closely approached in Fiber. 

Tig. 17.— Enamel pattern of 
molar teeth, Phenacomys 
cclatvs. (x5.) 



[Xo. 12. 

External form. — In external form the species of Fhenacomys show no 
peculiarities to distinguish them from the other voles. The body, tail, 
feet, ears, and eyes are usually jiroportioned about as in Microtns arra- 
lis or ]\[. ansierus. In F. longicauda, however, the tail is proportionally 
longer than in any of the other known species. 

General remarTcs. — Phenacomys is readily distinguished from Microtns 
by the rooted molars. From Uvotomys, rhenacomys is separated by 
certain characters in the form of the skull, and more especially of the 
bony palate, as well as by peculiarities in the teeth. The differences 
between the three genera may be comjiared in detail as follows: 




Koot of lower incisor above den- 

Eoot of lower incisor below den- 

Root of lower incisor bolow den- 

tal foramen. 

tal foramen. 

tal foramen. 

Molars rootless throughout life.. 

Molars rooted in the adult, the 

Molars rooted in the adult, the 

roots closed in extreme old 

roots closed in extreme old age. 

Molars large and strong, the 

Molars small and weak, the sal- 

Molars large and strong, the sal- 

salient angles sharp. 

ient angle rounded. 

ient angles sharp. 

Reentrant angles on oviter and 

Reentrant angles on outer and 

Reentrant angles on inner side of 

inner sides of lower molars ap- 

inner sides of lower molars 

lower molars verj' much deeper 

proximately equal in depth. 

approximately equal in depth. 

than those on outer side. 

Skull strong and angular 

Skull weak and rounded 

Skull strong and angular. 

Posterior border of bony palate 

Posterior border of bony palate 

Posterior border of palate never 

extremely variable. 

a thin-edged shelf continuous 
between alveoli of posterior 

a thin-edged shelf. 

Middle portion of zygoma dis- 

Middle portion of zygoma 

Middle portion of zygoma dis- 

tinctly expanded. 

scarcely expanded. 

tinctly expanded. 

Since the discovery of the genus Phenacomys the following species 
have been described: P. intermedins Merriam, P. celatus Merriam, P. 
ungara Merriam, P. latimanus Merriam, P. orophilus 3Ierriam, P. longi- 
caiida True, P. trnei Allen, and P. oramontis Ehoads. The status of 
these forms is wholly a matter of conjecture. 

C4enus EVOTOMYS C'oues. 

1839. Myodes DeS61y8 Lougcbamp.s, fitudes de Micromammalogie, p. 87, 1839 '(sec- 

1883. Ifyodcs Lataste, Le Natnraliste, Tome II, p. 349, 1883 (subgenus). 

1840. H'jpuda'us Keyserling and Blasius, Die Wirbelthiere. Europa.s, p. 34, 1810 (sub- 

genus). Type Miis glareolns Scbreber. (Not Hypnduus Illiger, 1811.) 
1857. Hypudaus Baird, Mamm. N. Am., p. 513, 18.57 (subgenus). 
1874. Evotomys Coues, Proc. Acad. Nat. Sci. Pbila., p. 186, 1874 (genusj. Type J/h« 

rutilus Pall 

Geographic distribution of type species. — xVrctic region in Europe and 
Asia, possibly in America also. 

Geographic distrihntion of genus. — Boreal Xorth America, Asia, and 

JCLY, 1896.] 



Essential characters: 

Upper incisors ■without grooves. 

Lower incisors with roots on ourer side of molars. 

Molars rooted. 

Enamel pattern characterized by approximate eiiuality of reentrant angles. 

m 1 with five closed or nearly closed triangles. 

m 3 with three closed triangles. 

Feet not specially" modified. 

Thumb Avith a small, pointed claw. 

Fur not specially modified. 

Tail longer than hind foot, terete. 

Sicull. — The skttll of Urotomi/s (PI. I, tig. -t), as compared with that 

of the other voles, is characterized by a general weakness and lack of 

angularity. All the outlines are full and 

rounded, and the ridges and furrows are slightly 

developed, even in extreme old age. The in- 

terorbital region is broader and the audital 

bulliie are larger and more inflated than usual in 

Microtus and Phenacomys. On the other hand, 

the zygomata are very slender and scarcely 

widened in the region of contact between the 

jugal and the zygomatic process of the maxillary. 

The mandible also is slender and weak. The 

bony palate terminates in a thin-edged shelf, 

continuous between the alveoli of the posterior 

incisors (fig. 7 and PI. II, fig. 10). The structure 

is very different from that found in Flienacomys 

and in typical Microtus} 

Teeth. — The incisors are exactly as in Phenacomys. The lower incisor 

runs back along the lingual side of the first and second molars, but 

crosvses the line of the molar tooth row between the second and third 

molars, terminating in the ascending ramus of the mandible at about 

the level of the middle of the posterior molar and distinctly below the 

dental foramen. The molars are rootless in the young (fig. 18), but in 
the adult each is provided with two distinct roots 
which eventually becomefull}- closed.^ In one very 
old individual the crowns of the lower molars are 
completely worn away, so that each root, with the 
exception of the anterior root of m 3 (which lias 
been shed) stands alone like a simple, round-topped 
tooth (PI. Ill, fig. 1). The molars are all very 

narrow and weak, in this character strongly contrasted with the strong, 

broad teeth of Microtus and Phenacomys. 

' For detailed comparison of the palates of Evoioniys and Microtus see pages 26-28. 

^lu the original description of the genus Phenacomys (North Am. Fauna No. 2, 
p. 30) it is stated that " Phenacomijs has genuine rooted molars, not half-rooted 
molars like those of Ecofomys, which grow from persistent pulps." Erotomys, how- 
ever, has as perfectly rooted molars as Phenacomys, though the roots do not close sa 
early in life. 

Fig. 18.— Side view of molars, 
Evotomys. (a) youny:, ^&) 
adult. (x3.) 

FiQ. 19.— Enamel pattern 
of molar toetli, Evotumyg 
gapperi. (x5.) 


In the number and arranoement of triangles the enamel pattern 
{fig. 19) is the same as that of the tetramerodont species of Microtus 
(see p. Co). The salient angles are, however, for the most part rounded, 
and so placed that the triangles are seldom fully closed. 

External form. — In external form Evotomys does not differ essentially 
from Microtus, although the ears are usually larger. The red or rufous 
color of most of the species gives them a very different appearance 
from the other voles. 

General remarks. — The characters which separate Evotomys from Mi- 
crotus and Phenacomys have been presented in such detail under the lat- 
ter that it is unnecessary to consider them further. The peculiar bony 
palate of Evotomys has been considered one of the best generic charac. 
ters. Since the discovery that it is perfectly reproduced in two subgenera 
of Microtus [Anteliomys and Eothenomys) it loses much of its importance. 

The genus Evotomys is represented in Europe, Asia, and North 
America by numerous species and subspecies whose interrelationships 
are at present little understood. Among the American species may be 
mentioned E. (japperi (Vigors), E. fuscodorsaUs Allen, E. galei Merriam, 
E. idahoensis Merriam, E. californicus Merriam, and E. occidentalis Mer- 
riam ; among those found in the Old World are E. rutilus (Pallas), E. 
glareolns (Schreber), and E. rufocanns (Sundevall). 

Geiinw MICROTUS Schrank. 

1798. Microtus Schrank, Fauna Boica, I, Iste Abtb., p. 72, 1798. Typt- by elimination 

Microtus terrestris Schrank = J/h8 arvalis Pall. 
1883. Microtus Lataste, Le Naturaliste, Tome II, p. 348, 1883. 
1801. Arvicola Lacdpede, Mem. de ITustitut, III, p. 489, 1801. Type ' Arvicola amplii- 

hiu8'^=Miis terrestris Linn. 

Geographic distribution of type species. — Central Europe and parts of 

Geographic distribution of genus. — In both hemispheres the genus 
Microtus ranges from near the northern limit of mammalian life to the 
edge of the tropics. 

Essential characters : 

Upper incisors without grooves. 

Lower incisors with roots on outer side of molar series. 

Molars rootless. 

Enamel pattern characterized by approximate equality of reentrant angles. 

m 1 usually with five closed or nearly closed triangles. 

m 3 with one, two, or three closed triangles. 

Tail nearly always longer than hind foot, terete. 

Feet, fur, eyes, and ears very variable. 

Thumb never with a well-developed ligulate nail. 

Skull. — The skull of Microtus varies greatly in shape among the dif- 
ferent subgenera. Eull descriptions will be given under each of these. 
Considering the genus at large it is difficult to frame any diagnosis by 
which the skull may be in every case distinguished from that of the 
other voles. Most of the characters which at various times have been 




adult Microtus alleni. (x 2.) 

brouyht forward for this purpose prove to be either wholly iueoustant 
or coustant only when particular subgenera are held in view. 

Tecih. — Although the skull of Microtus presents no tangible diag- 
nostic characters, the teeth are readily distinguishable from those of 
all other members of the subfamily. The upper incisors are never 
grooved except in oc<;asional abnormal specimens. The root of the 
lower incisor crosses the line of the molar 
series between the second and third molars, 
causing a greater displacement of the roots 
of the latter (PI. Ill, fig. 3) than occurs in 
anj'" other genus. It terminates in the ascend- 
ing ramus of the mandible at a point slightly 
above and behind the dental foramen (PI. Ill, 
fig. 3). The molars, even in extreme old age, 
are never rooted (fig. 20). This character 
alone distinguishes them from the molars of 
the other voles. The pattern of enamel folding- 
varies considerably in the different subgenera, and forms one of the 
numerous charactets by which the latter may be separated. Detailed 
descriptions of the enamel i)atterus are given in the accounts of the 

External form. — In external form the members of the genus jl/icro^Hs 
vary excessively. Some resemble lemmings so closely that they have 
been associated with these by certain writers. Others are modified for 
an aquatic life and in consequence have more the appearance of musk- 
rats {Fiber). Still others pass most of their time under 
ground. In these the ears, eyes, and tail are reduced, 
the front feet enlarged, and the fur so modified as to 
suggest that of the moles. The great majority of spe- 
cies, however, show none of these special adaptations, 
but resemble in a general way the members of the genera 
Phenacomys and Evotomys. Whatever may be the modi- 
fications in form, the tail is almost invariably longer 
than the hind foot and the thumb is armed with a small 
or rudimentary i)ointed nail (fig, 21). 
General remarks. — The characters of Microtus, as contrasted with 
Evotomys and Phenacomys^ have already been given (p. 42) and need not 
be repeated here. 

-Subgenus EOTHENOMYS ^ Miller. 
New subgeuus. Type Arvicola mc1a»o<jaster Milue-Edwards. 

Geographic (UstriMition of type species. — Moupin, western Sechuen, 
and western Fokien, China. (Blanford.) 

Geographic distribution of subgenus. — Microtus melanogaster is the only 
known species of Eothenomys, hence the geographic distribution of the 
subgeuus is the same as that of the type species. 

FlCJ.21.— Left front 
foot, Microtxta 

^'H(b?, the morniug (eastern); Qev, from; yui??, mouse. 


Essential characters : 

Palate abuormal. 

m 3 without closed triangles. 

m 1 witli triangles frequently open and 8 or 9 salient angles. 

m 3 -with triangles usually open and G salient angles. 

Mamma', (number not known). 

Plantar tubercles, 5. 

Sole hairy. 

Claws on hind feet longest. 

Fur apparently somewhat modified. 

SJiidl. — In tlie spechneus of Eothenomys that I have examined the 
skull is not in sufficiently good, condition to permit of auj^ detailed 
description. The peculiar structure of the bony palate taken in con- 
nection with. the teeth is, however, of itself enough to characterize the 

Bony palate. — Unfortunately in the two specimens of Microtus melano- 
(jaster that I have seen ( and, British Museum 
Register) the basal part of the skull is so injured that the form of the 
interpterygoid fossa can not be determined. 
The bony palate, however, is sufficiently pre- 
served to show the essential details of its 
structure (PI. II, fig. 11). That part of the pal- 
ate which lies in the level of the roof of the 
riQ. 22— Enamel pattern of moutli cuds abruptly oppositc the front end of 

molar teeth Microtu. (Eo. ^ ^ ^ j .^^ Straight-cdged Shclf 

the7iomys)inclanogaster. (yi 5.) ii o e> 

which extends without notch or projection from 
alveolus to alveolus. Although the form is thus strikingly different 
from that of the typical microtine palate, the vestiges of the structure 
there i^resent may still be recognized. The lateral grooves and median 
ridge are present, though slightly developed. The former terminate in 
two depressions lying just in front of the Avide, flat, lateral bridges 
which comjdetely obliterate the iDOsterior ends of the grooves, and 
together with the terminal part of the median ridge form the edge of 
the palatal shelf. The palate in all its essential characters is thus 
exactly like that of Evotomys. 

Enamel jyattern in general. — The enamel pattern in Eothenomys (ftg. 
22) is in many ways remarkable. The triangles in all the teeth tend to 
remain open, the points of the salient angles are blunt and rounded as 
in Evotomys, the triangles on the outer and inner sides of the teeth are 
subequal in size, and the maxillary teeth are especially noticeable for 
their likeness to each other. The figures published by Blanford^ fail 
to do justice to the teeth of this species. These are better represented 
in Milne-Edwards's original iilate,^ in which there is also a hint at the 
palate structure. 

ijourn. Asiatic See. Bengal, L, pt. II, PI. II, fig. A. 

2Recherches p. servir a I'histoire nat. d. Mammiferes, Vol. I, PL XLVI, figs. Ic 
and Id. 


Front loicer molar. — The lirst lower molar Las the usual trausverse 
posterior loop autl a moderately loug rounded anterior loop, with a 
strong salient angle at each side of the base. It has five lateral tii- 
angles, three on the inner side, two on the outer side. These may be 
perfectly isolated, or more often Avidely open. Except for the greater 
tendency to equality in the triangles, the teeth in the lower jaw do not 
differ very greatly from the mandibular teeth of true Microtus. 

Baclx upper molar. — The posterior maxillary tooth most nearly resem- 
bles that of Fedomys. The anterior loop is followed by two lateral 
triangles, subequal in size and more or less completely isolated from 
each other and from the anterior loop. The third lateral triangle is 
reduced to a strongly developed salient angle on the inner side of the 
posterior trausverse looj). A second salient angle is formed on the 
outer side of this loop, which thus appears as a crescent joined near 
the middle of its coucavitj' to the rest of the tooth. 

Other teeth. — The middle upper molar has a posterointernal loop 
nearly as large as the postero- external loop, the two placed opposite 
each other. The result is a tooth of practically the same shape as the 
one behind it. The anterior upper molar is likewise provided with a 
very large postero- internal loop opposite the loop on the outer side, 
normally terminating the tooth. Tiius it very closely resembles the 
two other maxillary teeth, differing only in its one more closed triangle 
at the front end. 

Mamma\ — The number of mammae in Eothenomys is unknown. 

Feet. — The feet are moderately hairy, in this respect not differ- 
ing from true Microtus. Blanford states that there are five well- 
developed pads on the sole and a rudimentary sixth. The claws are 
not greatly developed on any of the feet; those on the hind feet are the 

Fur. — A skin in the British Museum has the fur of a iieculiar, dense, 
mole-like quality suggestive of Pitymys. The specimen appears to be 
in worn coat, however, and this character may not be normal. 

General remarls. — Eotheaomya is such a Avell-jnarked subgenus that 
it is surprising to find that it has hitherto received no name. In tooth 
pattern it agrees iu a general way with Microtus siMimensiSj a circum- 
stance which induced Blanford to place it in the subgenus '■Xeodon ;^ 
but the palate structure is widely different from that of the subgenus 
Microtus, to which ^[. sil'lcijnensis I'eally belongs, while the similarity 
in the enamel pattern of the two species is very superficial. 

Snbgeuns ANTELIOMYS i Miller. 
New subgenus. Type Microtus dtinensis Tlioiuas. 

Geographic distribution of type species. — Microtus chinensis is known 
from one specimen collected at Kiating-fu, west Sze-chuen, China. 

' 'yJrr?)/\/o?, eastern; /iv?, mouse. 


Geographic distribufion of subgenus. — Microtus chinensis is the ouly 
known si^ecies of the subgenus. 
Essential characters : 

Palate abnormal. 

m 3 without closed, triangles. 

HI 1 with triangles mostly open, and with 9 salient angles. 

Ill 3 with triangles mostly open, and with 9 salient angles. 

Mamma', 4. 

Plantar tubercles, 6. 

Sole moderately hairy. 

Claws on hind feet longest. 

Fur not specially modiiied. 

Skull. — As remarked by Mr. Tliomas in the original description of 
Microtus chinensiSy the skull of Anteliomys resembles in a general way 
that of Evotomys. Unfortunately, I am nnable to add any more deiiuite 
information concerning its characters. 

Bony palate. — The palate of Anteliomys (PI. II, tig. 8) is similar to that 
of Eothenomys, except that the median ridge is produced backward as a 
distinct spike lying perfectly in the plain of the roof of the mouth. 

Just in front of the strongly developed lateral 
bridges, the posterior edges of which form the 
back rim of the bony palate, lie two pits, iu 
which terminate the lateral grooves. These 
pits communicate freely over (dorsad to) the 
riG.23.— Enamel pattern of mo- lateral bridgcs with the anterior end of the 

lar teeth, Microtus (Aiiteli- i i , • i x- 

' . ' . , , , broad mesopterygoid lossa. 

owyx) chmensis. (x 5.) ^ ••' ^ 

Enamel pattern in (/encral. — The enamel pat- 
tern in Anteliomys (fig. 23) is characterized by rounded angles, imper- 
fectly closed triangles, and great complexity in the prisms of the back 
upper molar. 

Front lower molar. — The anterior lower molar is made up of four 
transverse, perfectly isolated loops. The anterior loop is much the 
largest and contains three salient angles (two on the inner side). Each 
of the succeeding looi)S has two salient angles. The tooth thus con- 
tains exactly the same elements as the corresi)onding one in Microtus, 
the difference in form being due to the fact that in Anteliomys the 
prisms are placed ojiposito each other instead of alternately. The 
Ijrisras on the opposite sides of the tooth are nearly equal in size, 
thus producing the bilaterally symmetrical appearance found to a less 
degree developed in Alticola and Eothenomys. The figures iu the 
original description of Microtus chinensis^ give a very poor idea of the 

Back npper molar. — The posterior maxillary tooth is like that of true 
Microtus except that the posterior loop is greatly lengthened and on 
the lingual side cut by two reentrant angles, of which the anterior is 

' Ann. & Mag. Nat. Hist., Ser. 6, Vol. VIII, p.- 118, August, 1891. 

July, 180G.] SUBGENUS LAGURUS. 49 

the deeper. TJiere is a salient augie at the outer base of the posterior 
loop and the outer border is faintly crenulate. A tooth with nine well- 
developed salient angles is the result. 

Other teeth. — The front maxillary teeth are exactly as in tetranierodont 
Microtus. The back molars of the lower jaw are likewise in no way 
peculiar. Tliey both, however, have the prisms on the two sides oppo- 
site, tlius lacking all ch)sed triangles. 

There is nothing worthy of note in the form of the incisors. 

Mamma'. — In the unique type specimen of Microtus chinensi-s, which is 
a female, there are four teats, all inguinal. 

Feet. — The sole is well haired from heel to tubercles. There are six 
pads on tlie sole, all well develoi)ed. 

Fur. — The fur is not specially modified. 

General remarls. — In its i>alate structure AnteUomys is related to 
Fothenomys, and more remotely to Alticola, together with Avhich it 
bridges the gap (so far as the palate alone is concerned) between Micro- 
tits and Erotomijs. Tliese facts were in part noticed by Mr. Thomas, 
who says in the original account of il/. chinensis : 

Iji some respects it seems to be .■uiuecteiit between Evotomijs and the rest of the 
voles, the structure of its palate and some of its dental characters [opposite prisms 
and rounded anj^les] showing striking affinities to the former, far as itsrootless teeth, 
fewer mamma-, and difterent external form separate it from any of the known mem- 
bers of that group. 

The enamel r)attern is, however, very difterent from that of Frotomys, 
while the resemblance to that of its nearest relative, FotJtenomys, is 
almost equally remote. 

Mirrotn.s chinensis is the only species of Anteliomys thus far known, 
i\u](iSii 2Iicroti(s m?V/r7e«fZor/f/^" (Polyakofty from Siberia- proves to be 
a member of the same group. The figure of the teeth in the original 
description of M. mid (lend or ff it is suggestive of Microtus chinensis, 
though the triangles are very strongly isolated. Neither the palate 
structure nor the number of mammte is given by Polyakoff, so it is 
impossible to come to any conclusion on the subject of the animal's 
true status. 

Subgenus LAGURUS Gloger. 

1841. Lagurus Gloger, Gemeinu. Hand-u. Hilfsbuch d. Naturgesch., p. 97, 1841 

(genus). Type, Lagurus viigratorius Gloger^ If hs lagurus Pallas f^ 
1895. Lagurus Merriam, Am, Naturalist, XXIX, p. 758, Aug., 1895 (subgenus). 

' Mem. Acad. Imp. Sci., St. Petersbourg, XXXIX suppl., p. 70, 1881. 

-Polyakoff gives the following localities: Taimur, Vilui River, Ayan, and Kara 

^In restoring the generic name Lagurus (Aim. & Mag. Nat. Hist., 6th ser., XV, 
Feb. 1, 1895) Mr. Thomas gives the species lagurus as the type. It appears highly 
probal)le, however, that Gloger's Lagurus migraiorius is the Llypudaus migratorius 
of Lichtenstein (Eversmann's Reise nach Buchara, p. 123, 1^2^)^=^ Microtus {Lagurus) 
luteus (Eversmaun). 

16933— Xo, 12 4 



[No. 12. 

1881. Eremiomiis Polvakoft', Mem. Acad. Imp. Sci., St. Petersbourg, XXXIX ^uppl.,p. 
34, 1881 (genus). Type J/(ts latjnrns Pall. 

Geographic distnhution of type species. — Plateaus of western and 
central Asia. 

GcoyrapMc distribution of suhgenua. — The range of the subgenus 
Lagurus is very imperfectly known, but probably extends over a large 
liart of the Boreal region in Asia and in western Xortli America. 
Essential characters: 

Palate slightly abnormal. 

m 3 normallj' witli 2 or 3 tightly closed triaugles. 

m 1 normally with 5 closed triangles and 8 or 9 salient angles. 

m 3 normally with '2 or 3 closed triaugles and 5 or 6 salient angles. 

Mamma', 8. 

Plantar tubercles, 5. 

Sole very hairy. 

Claws on hind ieet longest. 

Fur not specially modihed. 

Slaill. — The skull of Lagurus (PI. I, fig. 7') may be at once recognized 
by the form of the audital bulla? (fig. 24). These are larger than in any 
other subgenus of Microtus, and are especially remarkable on account 
of the way in which they project backward behind the x)lane of the 

occiput. Aside from the audital bullae, 
the skull does not differ very notice- 
ably from that of I'iti/niys or Chilotus. 
As compared with that of Pitymys, 
however, tlie rostrnm is considerably 
more slender. The dorsal outline is 
flat, as in Chilotus. 

Bony palate. — The bony palate (PI. 
II, fig. 1') is normal in structure but 
there is less diiference than usual between the levels of the portions 
lying in front of and behind the lateral bridges. A peculiar flat palate 
with shallow lateral pits and broad, ill-defined median sloping ridge 
is the result. This form of j)alate is much like that of Fhenacomys 
(PI. II, fig. 1). 

Efiamel pattern in 
general. — The enamel 
pattern of Lagurus 
(fig. 25) is character- 
ized by the tight clos- 
ure of all triangles, 
notably in the back 
lower molar, and the 
great width of the reentrant angles 

Fig. 24.— Audital buUsB, (a) Microtus {Mi 
crotui) arvalis ; (6) M. (Lagurus) pallidus 
(X 2.) 

Fig. 25.— Enamel pattern of molar teeth : (a) Microtug (Lagurus) 
pallidus; (b) 21. (L.) lagurus; (c) M. (L.) luteus. (x5.) 

The latter peculiarity gives the 

'See also Naturwissenschaftliche Resiiltate der von N. M. Przewalski unternom- 
meneu Reiseu, PI. XIII, figs. 1, 2, 3, 12, 13, and 14. 

July, 1896.] SUBGENUS LAGURUS. 51 

teetb a drawn-out appearance, wliicli is liighly cliaracteristic. Wide 
reeutraut angles occur in the teeth of the young- of all Microti; in 
Laf/urus this embryonic character is retained by the adults. 

Front lower molar. — The number of loops and triangles in the first 
mandibular tooth is the same as in true Microtus. In Microtus prze- 
icalslcii and Microtus Inteiis the anterior loop is simple and much 
reduced, while in Microtus lagiirus and M. pallid us the loop is exactly 
as in Microtus arvalis. 

Bad- tipper molar.— The posterior maxillary tooth differs considerably 
in form among the various species. In certain American species the 
loops and angles are arranged exactly as in M. (Arvicola) terrestris, 
while in M. przeicalslvH and M. lutens the tooth, although retaining the 
same number of elements, is remarkably like that of some of the spe- 
cies of Alticola. (See PI. XIII, Wissensch. Eesnltate der von K. 
M, Przewalski nach Cent.-Asien nntern. Keisen. Zool. Theil, Ed. I, 
Lief. 3.) This resemblance to Alticola results from the unusual elonga 
tion of the i)osterior loop. In Microtus lagurus there are three tightly 
closed triangles, and the terminal loop has a well developed salient 
angle on each side at the base. 

Other teeth. — In the Old World species (fig. 25) the back lower molar 
contains four tightly closed triangles. The American species, however 
(fig. 25), so far as known, have only three closed triangles in this tooth. 
The other molars are always formed as in tetramerodont Microtus. 
There is nothing peculiar about the incisors. 

Mam)tia\ — In 2[icrotus pallidus, or a closely related form, there are 
eight mamnipe, four pectoral and four inguinal. I have been able to 
find no statement of the number of mamm;^ in the Asiatic species. 

Feet. — Soles densely hairy as in Phaioinys and the lemmings; plantar 
tubercles, five; claws moderately developed, those on hind feet longest. 

Fur.-^ThQ fur is full and soft, but not highly modified. In color 
most of the species are dull yellowish or grayish. The marking of 
Microtus lagurus is unique in the genus Microtus on account of the 
strongly developed and sharply defined dark dorsal streak. 

(General remarhs. — The subgenus Lagurus is a strongly characterized 
group, but, as Dr. Merriam has remarked,' the species show no pecul- 
iarities to separate them generically from Microtus arvalis. In Microtus 
lagurus, M. luteus, and M. przeicalslii, the tail is usually shorter than 
the hind foot, thus adding to the superficial resemblance to the lem- 
mings. No other voles have the tail so short. 

The subgenus Lagurus is represented in the Old World by Microtus 
lagurus (Pallas), 21. luteus (Eversmann), and M. przeicalsldi (Biichner). 
In America there are probably numerous species and subspecies. 
Among- these may be mentioned Microtus pauperrimus (Cooper), il7. 
curtatus (Cope), and M. pallidus (Merriam). 

'American Naturalist, XXIX, p. 758, August, 1895. 


Subgenus ALTICOLA Blanford. 

1884. AUicoIa Blanford, Jouru. Asiat. Soc. Bengal, L, Pt. II, p. 89, 1884. Type 
Arvicola stolicskaiius Blanford. 

Geographic distribuiion of type species. — " High plateaus of Northern 
Ladali (Western Tibet)" (Blanford). 

Oeographic disirihuiion of subgenus. — Boreal Zone in the Himalayas. 
Essential characters : 

Palate abnormal. 

m 3 without dosed triangles. 

m 1 with 4 or .5 closed triangles and 7 salient angles. 

m 3 normally with 2 closed triangles and 5 or 6 salient angles; posterior loop 
produced backward iu line of jaw. 

Mamnut, §. 

Plantar tubercles, 6. 

Sole, hairy. 

Claws on hind feet longest. 

Fur long and soft but not highly modified. 

Skull. — The skull in this subgenus (PI. I, fig. 10) shows no striking 
peculiarities to distinguish it from that of trne Microtus. The general 
shape is usually much as in Microtus arvalis, 
but the zygomatic arches are more flaring and 
the brain case is somewhat broader and flatter. 
The rostrum is proportionally longer than iu 
rio.26.-Enan,eipatternofmo- Microtus propcr, and the audital bnllaj (fig. 27) 
lar teeth, Microtus {.AUicoia) are more inflated aud papery. 
aibicauda {type), (x 5.) i5oH7/ ^;o /a ^6.— The median palatal ridge (PI. 

II, fig. 4) widens at a point opposite the space between the second and 
third molars and is approached, as in the typical microtine palate, by 
outgrowths from the opposite sides of the lateral grooves. These out- 
growths, however, do not meet the median ridge, but leave the lateral 
grooves open. Just at its widest point the median ridge is squarely 
truncated. The sloping terminal ridge is entirely lacking and the si)ace 
that it usually occupies forms the anterior end of the very long rectang- 
ular interpterygoid fossa. A structure of nuich the same appearance 
could be produced by widening tlie anterior end of such a hastate 
interpterygoid fossa as that often present in 'Aulacomys'' (PI. II, fig. 7) 
until the whole space acquired an equal breadth. The floors and median 
w^alls of the lateral pits would then be so encroached upon as to oblit- 
erate the pits, while a few slight further modifications would give a 
l^alate indistinguishable from that of AUicoia. The palate of Alticola 
resembles that of JS^eofiber more closely than it does that of any other 
subgenera excei)t Hyperacrius. 

Enamel pattern in general. — The enamel pattern in Alticola (fig. 26) 
differs in many ways from that of any subgenus of Microtus. In gen- 
eral it is characterized bj^ {a) a tendency to reduction in the number of 
prisms in the variable teeth; (&) by a peculiar irregularity and iiulefl- 
niteness in outline j (c) by a strong tendency toward bilatei'al symmetry 

July, 1896.] SUBGENUS ALTICOLA. 53 

caused by tlie approximately equal size of tlie triangles on the opposite 
sides of the teetli, and (d) by the form of the posterior upper molar. 

While the figures published by Blanford ' in his paper on the voles of 
the Himalayas, Tibet, and Afghanistan are in many ways inaccurate, 
they give an excellent idea of the general appearance of the teeth in 
the voles of this group. 

Front lower molar. — The tirst mandibular molar has normally four 
closed triangles and seven or eight salient angles. Earely a fifth closed 
triangle is isolated at the inner basal angle of the anterior loop. The 
form, relative position, and degree of isolation of the triangles and 
transverse loops vary greatly witli the different species. Any one of 
the reentrant enamel folds may fail to reach the enamel of the opposite 
side, and consequently any of tlie triangles may be open at one or both 

BacTi upper molar. — The posterior maxillary tooth varies in form in the 
dift'erent species. It is, however, always recognizable by the backward 
prolongation of the posterior loop in the line of the jaw, a character 
which is found elsewhere in HyperacrhiSj OhilotuSy and Laguru.s only, 
and in all but the first of these developed to a much less degree. This 
attenuate posterior loop is followed by three or four more or less incom- 
pletely isolated lateral triangles, these by an anterior loop of the usual 
form. The tooth is most complex in M. roylei and i¥. hhmfordi, in each 
of which it has six salient angles and two or three closed triangles. 

Other teeth. — Except for the stronger tendency to bilateral symmetry 
combined with slight irregularity of outline the other molars do not 
differ from those of ordinary tetramerodont Microtiis. 

Mamma\ — The number of mamnnt^ in the species of Alfivola has 
apparently not been recorded. Blanford does not mention it in his 
descriptions of any of the species, and Mr. G. E. H. Barrett-Hamilton, 
who has made at my re<xuest a special examination of the material in 
the British ^Museum, is able to add nothing on the subject. In an 
adult nursing female of a sjiecies of Alt icola closely allied to Microtus 
albicauda (Xo. 62162, U. S. Nat. ]Mus. Ladak side of Kara Korum 
Pass, Kashmir) there are eight well-developed mamma?. Hence there 
is little doubt that eight is the normal number in the subgenus. 

Feet. — The feet are very hairy, the long hairs on the dorsal surface 
often nearly concealing the claws. Plantar tubercles six. The claws 
on all the feet are long and slender, those on the hind feet longer than 
those in front. 

Fur. — As in most high boreal micro tines the fur is long and full. 
Otherwise it is not peculiar. 

General remarls. — The subgenus Alt icola is one of the best character- 
ized groups in the genus Microtus. The pattern of enamel folding is 
uulike that of any of the other subgenera, except Hyperacrius, while 
the palate structure is approached by that of Hyperacrius and the 

' Jouru. Asiatic Soc, Bengal, L, Pt. II, PI. I, tigs. B, C, D, and E. 


otherwise widely difterent Xeojiher ouly. The tendency to bilateral 

symmetry in the molars is sliared by three other Asiatic subgenera, 

Hi/peracriufi, Uothcnomi/s, and AnteJloiny.s. 

Alticola, like Ei/jieracriu.s, is apparently a strictly boreal subgenus. 

The following species are known : Mkrotus stoliczlcanus Blanford, M. 

roylii (Gray), .If. stracheyi (Thomas), Tlf. hlanfordi (Scully), and M. 

albieauda (True). 

Subgenus HYPERACRIUSi Miller. 

New subgenus. Type Jrvicola fertHis True. 

Geographic distrihuiUm of type species. — "Central Kashmir, the Pir 
Panjal Range and the Kaj Nag Mountains." (True.) 

Geoyraplilc distrlhiition of suhgenns. — Mountains of central and south- 
western Kashmir at elevations ranging mostly from 7,000 to 12,000 feet. 

JEssential characters : 

Palate abnormal. 

m 3 without closed triaugies. 

Ml 1 noruially witli 4 or 5 closed triaugies aud 7 salient angles. 

m 3 normally with 1 or 2 closed triangles and 4 salieut angles. 

Mammji' 4. 

Plantar tubercles 5. 

Sole hairy. 

Claws on hind feet longest. 

Fur short and dense. 

Skull. — The skull in the subgenus Byperacrlus (PL I, fig. 11) differs 
from that of Alticola in its longer rostrum, strongly cuneate nasals, 
narrower interorbital constriction, more abrui^tly flaring zygomata, and 

flatter brain case. The whole dorsal 
outline of the skull is depressed so 
that the zygomata are more nearly on 
the level with the top of the skull 
than in any other subgenus oi Micro- 
tus. The audital bullne (fig. 27) are 

Fig. 27.— Audita] bullae, (a) Microhis {Alti- proportionally Smaller than in Alti- 
cola) albieauda; (h) M. {Hinjeracnus} fer- 7 , ^r- , -jf, rri , 

tiiis (x2) cola, true lUicrotus, or rdymys. ihe 

brain case is much more depressed 
than in Microtus i)roper (flatter even than in Fitymys), and viewed from 
above it has a peculiar subcircular outline not known elsewhere in the 
genus. Parietals proi^ortionally smaller than in Microtus proper; 
squamosals and interparietal proportionally larger. The latter in old 
individuals has much the same shape as in fully adidt Arvicola, 
Keojiher, aud Fiber. 

Bony palate. — The bony palate is exactly as in Alticola. 

Enamel pattern in general. — The enamel pattern (fig. 28) has the gen- 
eral appearance of that of Alticola. 

Front loicer molar. — The first mandibular tooth is indistinguishable 
from the corresponding tooth iu Alticola. 

* Oi vnepdnpioi, inhabitants of the heights. 

July, 1800] SUBGENUS PEDOMYS. 55 

Bad' upper molar. — The last maxillary tooth has the same general 
form as that of Alt i col a, but is simpler iu structure, thus recalling 
the corresponding tooth in Lcuiurus (flg. 25). There are usually only 
two lateral triangles and four salient angles. The posterior loop is 
lengthened in the axis of the jaw as in AliicoJa. 

Ma mm (('.—There are four maramte, all inguinal. 

Feet. — The feet are well haired, but rather less densely than in ^1/^/- 
cola. Plantar tubercles five — the faintest possible trace of a sixth 
sometimes present. Claws on all four feet well developed, those on 
hind feet longest. 

Fur. — The fur is much shorter and more dense than in Alticola. 

MisceUaiicous characters. — The ears, and a])parently the eyes, also, 
are smaller than in Alticola. The whiskers are very short, reaching 
scarcely to the ears, while in Alticola they are probably longer than iu 
any other subgenus of Microtus. 

General remarls. — Hyperacrius is most closely related to Alticola, from 
which it differs chiefly in its highly modified skull and reduced number 
of footpads and mammjc. Minor differences are to be found in the rela- 
tive size of the ears and in the character of the feet. Hyperacrius 
appears to be modified for a more strictly underground life than Alticola. 
It requires no close comparison with any other 
subgenus, though it bears a superficial likeness 
both in external form and in cranial characters to 
Pitymys. The structure of the bony palate and 
the pattern of enamel folding readily distinguish fig. 28.-Enamei pattern of 
it from the latter, however. '""i-'^"' ^'^^'^i'' ^ierotus (Hy- 

v\ hether Microtus irynnei may be associated 
with Microtus fertil is in the subgenus Hyperacrius is a matter of doubt. 
Atmy request Mr. G. E. 11. Barrett-Hamilton has examined the speci- 
mens of AW/coZa in the British Museum with special reference to the 
relationships of M. a-ynnei. He finds that this species, as already 
noticed by Blanford, has only five plantar tubercles, but that in other 
characters it does not agree with the brief diagnosis of Hyperacrius, that 
I sent him. The fur is long, as iu the species of Alticola, and the skull 
apparently lacks the peculiar form seen in Hyperacrius. The number of 
mamm^cannot be determined in M. wynnei nor in any of the species 
of Alticola in the British Museum. For the present it is not safe to 
attempt to refer ilitcrofws ^cynnei definitely to one subgenus or the other. 

Subgeuns PEDOMYS Baiid. 
1857. Pedomys Baird, Mamm. N. A., p. 517, 1857. Type Jrvicola aiis1e7-us LeCoute. 

Geographic distribution of type species. — Transition and Upper Austral 
zones in the central United States and adjoining British Provinces. 

Geographic (listribution of subgenus. — The range of this subgenus is 
the same as that of Microtus austerus, the only known species. 
Essential characters: 
. Palate normal, 
m 3 without closed triautfles. 


ui 1 normally witli 3 closed truiuglcs and 8 or 9 salient angles. 

ni 3 normally with 2 closed triangles and 6 salient angles. 

Mamma- 4. 

Plantar tubercles 5. 

Sole thickly haired between heel and tubercles. 

Claws moderate in length, those on hind foot longest. 

Fur not specially modified. 

Sl'uIL — The skull of Microins austerus, the ouly kuown si^ecies of 
Pedomys, is remarkable for the subcyliiidric brain case, and great depth 
of all that part back of the rostrnm. While the skull of Pedomy.s is not 
strikingly different from that of true Microtus,^ it is very unlike the 
flattened skulls of Phaiomys, Pitymys, and CJiilohis, the other groups of 
small voles resembliug* Pedomys in tooth cliaracters and in number of 
mamma? and' footpads. 

Bony palate. — The bony palate is typical, though the interpterygoid 
fossa is seldom squarely truncate anteriorly. 

Enamel pattern in general. — The enamel i)attern (fig. 29) is charac- 
terized by simplification in the structure of the variable teeth. 

Front loircr molar. — The first mandibular molar has a posterior trans- 
verse loop followed by three closed triangles and an anterior loop. 

The anterior loop is deeply indented by two 
reentrant angles, one on each side. These 
sometimes cut deep enough to isolate a fourth 
or even a fifth closed triangle, but this rarely 
takes i)lace. There is often a very faintly de- 
FiG. 29.— Enamel pattern of mo- vclopcd reentrant angle close to each side of 
lar teeth, Microtus (redomys) ^^^ ^{^-^ ^^^ ^^^^ autcrior loop. lu cascs wlicre 

these are strongly marked a front tooth pre- 
cisely resembling that of Microtns is the result. 

Bacli upper molar. — The posterior maxillary tooth is exactly like that 
of Neojiher^ Pitymys, Phalomys, Chilotus, and typical Arrlcola, havhig 
an anterior transverse loop, two closed triangles and a short posterior 
loop, from the outer base of which a third closed triangle may some- 
times be cut. 

Other teeth. — With the exception of the two teeth just described, the 
dentition of Pedomys is like that of the tetranierodont species of the 
subgenus Microtus. 

Mam))ia'. — There are four mamm.e, all inguinal. 

Feet. — Soles densely hairy between heel and tubercles; pads five, 
with no indication of a rudimentary sixth. 

General remarls. — Pedomys agrees in tooth pattern with Pitymys, 
Chilotns, and Phalomys, but dilfers from all three in the shape of the 
skull, and from the last in the short claws and unmodified fur also. 

Subgenus PHAIOMYS P.lytli. 

1863. Phaiomi/s Blyth, Jouru. Asiat. Soc. Bengal, XXXII, p. 89, 1863. Type I'liaiomys 
leucttriis Plyth^l/^/cro^Ms blythl Blaudibrd. 

'A skull of Microtns ratticeps from Norway exactly resembles skulls of M. austerus 
except that the rostrum is more slender. 

July, 1896.] SUBGENUS PHAIOxMYS. 57 

1887. Lasiopodomys Lataste, Annali dtl Mvis. Civ. di Storia Naturale di Geuova, ser. 
2a, Vol. IV, i>. 268, 1887. Type Arricola In-anti Radde. 

Ge(i(ircq)hic distribution of type sjjecies. — -'Banks of Tslio Morari and 
Pankoug lakes, Western Tibet, also between Seh and the PankongLake 
at elevations above 13,0C0 feet." (Blanford.) 

GeiKirapltic distyihutioii of sulxjcnus. — High i)lateau region of central 
and southern Asia. Probably does not occur below the Boreal zone. 

Esse ntial cha racters : 

Palate normal. 

m 3 Avitliout closed triangles. 

m 1 normally with 3 to 5 closed triangles and 8 or 9 salient angles. 

m 3 normally with 2 to 3 closed triangles and 6 salient angles. 

Mamma' j^robably 10. 

Plantar tubercles, 6. 

Sole very hairy. 

Claws very long and of abont 0(jual length on all four feet. 

Fur remarkal)ly long and soft. 

*S'A-»7/.— Tlie skull of Phaiomys as compared with tliat of Pedomys is 
readily distinguished by its very different form. The brain case in 
Pedowys is higb, long, and almost cylindrical, while that of Phaiomys 
is short, broad, and flat. The zygomatic arches are more broadly flar- 
ing in Phaiomys than in Pedomys, while the 
upper incisors are usually more promiuent. 
The latter character is, however, inconstant. 

Bony palate. — The bony palate is perfectly 
normal and requires no detailed description. 

Enamel pattern in yeneral. — The enamel ]iat- i^k;. 30.— Enamel pattern of 
tern (fig. 30) is exactly like that of Pedomys, moi^r teeth, Microtus (Phai- 

J. XI i. . 1 . " . . 1 • — .> omi/s) strauchi. (x 5.) 

except that the outer reentrant angles m m 3 

are somewhatlessdeveloped, while the anterior outer reentrant angle in 
m 2 usually divides tlie anterior loop into two closed triangles. These 
dijferences, however, are trivial and inconstant. 

Other teetli. — In some of tbe members of the subgenus the incisors 
are directed more forward than usual. The character is, as already 
stated, wholly inconstant. 

Mamma'. — There is still doubt as to the normal number of mamma? 
in the subgenus Phaiomys. Milne-Edwards found only four in a skin 
of .1/. mandrianus ; Biichner found six in a skin of M. straxchi, and ten 
in a skin of M./uscus. I am inclined to think that ten will prove to be 
the correct number.^ In the specimen of M. fuscns just referred to 
there were six pectoral mamma*, the rest inguinal. 

Feti. — The feet are large and densely haired. The number of tuber- 
cles on the sole is still a matter of doubt. Biichner records six in both 

* That Phaiomys probably has a large number of mammae — at least more than four — 
■was suspected by Lataste, who in 1887 (Annali del Museo Civico di Storia Xatnrale 
di Genova, Serie 2a, Vol. IV, p. 270) called attention to the fact that Blyth found 
ten embryos in a female Microtiis blyihi. 


31. hramlti and M. strauchi, but I am able to find only five iu a skin of 
the latter, even after tliorouglily relaxing the foot. It is probable that 
six is tlie real number, as Bilchner's determinations were made from 
alcoholic vspecimens. The claws on all four feet are large and about 
e(]ual in length. That on the thumb is well develoj)ed — in this resi)ect 
perhaps surpassing all other subgenera of Microtiis. 

Fur. — The fur is long and soft, suggesting that of a lemming rather 
than that of a vole. 

General remarls. — In many respects Fhaiomys resembles Fedomys so 
closely that I should hesitate to sei)arate the two groups were they not 
already named. There are, however, such differences between them 
that it is impossible to call them the same, while in all probability more 
satisfactory material than that now available would show additional 
characters. In external ai)pearance the two subgenera differ consider- 
ably. While Fedomys is a typical vole, Fhaiomys bears a general resem- 
blance to the lemmings. The peculiar aspect of the species of Fhaiomys 
is caused by their short tails, large feet, and long, soft fur. The like- 
ness between the species of Fhaiomys and the yellowish species of the 
subgenus Lagurus is even more striking. From the latter, however, 
they are readily separable by dental characters. 

Mlcrotus hlythi (Blanford), M. mandarinus (Milne-Edwards), M. strauchi 
Biichner, Jlf. /?/,s'c?/s (Biichner), and M. hrandti (Iladde), are perhaps the 
best-known species of the subgenus Fhaiomys. 

Subgeuns PITYMY8 Mclvlurtrie. 

1830. J'sammomys LeCoute, Ann. Lye. Nat. Hist., New York, HI, p. 132, 1830 (genus). 

Type rsammomijs pinetorum Le Conte (uoc rsammomys Cretzsclimar 1828). 

1831. Pltymijs McMurtrio, American edition, Cuvier Ri-gne Animal, I, p. 434, 1831 

(genus). Type rsammomys pinetorum LeCoute. 
1857. rUymys Bainl, jMamm. N. Km., p. 517, 1857 (section; 
1887. Tilymys Latasto, Aunali del Mus. Civ. di Storia Naturale di Cenova, serie2rt, IV, 

p. 266, 1887 (subgenus). 

1831. Ammomys Bonaparte, Saggio Distrib. Metod. degli Auim. "\'ert., p. 20, footnote, 

1831 (genus). Tj'pe Psammomys 2>i»etornm Le Conte. 
1836. Finemys Lesson, Hist. Nat. d. Mamm. et Ois d(^coiiv. depuis 1788, Compl. 

Oouvres de Bufl'ou, Y, p. 436, 1836 (genus). Type rsammomys piuetorum 

1867. TerricoJa Fatio, Les Canipaguols du liassin du Leman, ji. 36, 1867 (subgenus) 

{sul)terranens and savii). 
1876. Micrunis Forsyth Major, Atti dclla Societa Toscana di Sci. Nat., Ill, fasc. I, 

p. 126, 1876 (subgenus). Type Arricola nehrodensrs Mina Palumbo. 

Geoyraphic distribution of type s2)eeies. — Austral Zone in the eastern 
United States. 

Geographic distribution of subgenus. — Central and southern Europe, 
eastern United States, i)arts of Mexico. 
Essential characters : 
Palate, normal, 
m 3 without closed triangles, 
m 1 uormallv with 5 closed triangles and 9 salient angles. 

July, 189(3.] SUBGENUS PITYMYS. 59 

111 3 normally with 2 or B closed triangles and 6 salient angles. 

Maninne, 4. 

Plantar tubercles, 5. 

Sole moderately liairy. 

Claws on front feet longest. 

Fur short, dense, and mole like. 

Sk-ulL — The skulls of the species of Pitj/mys differ considerably among 
themselves. In Microtus i)metorum (PI. I, fig. 2), the most highly modi- 
fied, the brain case is very broad and flat and the interorbital region is 
remarkably wide. The brain case is like that of Lagurus, but the broad 
anterior x^art of the skull is very different from the latter. The dorsal 
outline is strongly arched, esj)ecially anteriorly from the region between 
the orbits to the tips of the nasals. The arching is, however, no more 
strongly marked than in Microtus arvaUs. In Microtua suhUrraneus 
the skull is like that of 2[. pinetorum^ but the i^eculiarities are less 
accentuated. In the Mexican species of Fiiymys the brain case is 
narrower and higher than in J/, pinctorum, and the anterior part of 
the skull is less heavily built. The zygomatic 
processes of the inaxilhe stand out more 
nearly at right angles with the side of the 
skull, thus ])ringiug the broadest part of the 
zygomatic arch farther forward than in 21. 

Bony pahde, — The palate is normal, though 
the region between the posterior molars is in 
M. pinetorum rather flatter than. usual in true -pm. si.— Enamel pattern of 
Microtus, and the anterior outline of the inter- ^"^^^ teeth, (a) Jiicrotus 
pterygoid tossa is otten somewhat hastate. j^ {P)savii (x5 ) 

Enamel pattern in general. — With the excep- 
tion of the front lower molar and back upi:)er molar, the enamel ])attern 
(fig. 31) is that of tetramerodont Microtus. 

Front lower molar. — The anterior mandibular tooth contains the same 
number of looj)s and angles as the corresponding tooth in Microtus 
arralls. As a rule, however, the first and second triangles are not 
comx)letely isolated from each other or from the anterior loov). The 
tooth is therefore exactly as in Fedomys. 

Back upper molar. — The i)osterior maxillary tooth is simplest in the 
American species of the subgenus. In these it is like the back upper 
tooth in Fedomys and Arvlcola, which contain two closed triangles 
and an anterior and posterior loop. In M. subterranetis, however, the 
tooth is formed exactly as in M. arralis, while in M. saril it is some- 
what intermediate. In the last-named species the terminal loop is 
slightly larger than in M. pinetorum^ and a third closed triangle is 
usually cut oft' from the outer base. 

Other teeth. — There is nothing peculiar about the incisors or remain- 
ing molars. 

Mamma'. — In Fitymys there are only four nuimmte — all inguinal. 


Feet. — The soles are moderately hairy. They have five well-devel- 
oped tubercles, l)ut no trace of a sixth. The claws are well developed 
on all the feet, those on the front feet either equaling or exceeding 
those on the hind feet. 

In M. pinetorum the front feet are much larger and the front legs 
shorter than in true Microfus. These peculiarities are less developed 
in M. suhtemmeus and M. savii. Of the other species 1 have not seen 
alcoholic specimens, and so am unable to say which of those mentioned 
they most closely resemble. 

Fur. — The fur in all the Icnown species is remarkably short and dense. 
This character is most noticeable in M. pinetorion, which has an almost 
mole-like coat. 

Miscellaneous eharacters. — The tail, eyes, and external ears are much 
reduced in all the species of nti/mys. These characters, as well as the 
peculiarities of the fur and front feet, are distinctly adaptive and fit 
the animals for their underground life. 

General remarks. — While Pitijinys agrees with P<;^Z(:>^>?_(/s in the number 
of mammie and footpads, it is readily distinguished by its highly mod- 
ified fur, small eyes and ears, and flattened skull. The type and most 
extremely developed species is further characterized by its greatly 
shortened front legs. 

Pitymys is represented in Anierica by Microtus ijinetoruin (Le Conte) 
and several forms related to 21. qiiaxlater (Ooues). In Europe a num- 
ber of species and subspecies occur. Among these the best known 
are M. suhterr<iHeus (De Selys Longchamps) and J/, savii (De Selys 

Subgenus CHILOTIIS Bairtl. 

1857. Chilotu-s Baird, Mamni. X. Am., j). 510, 1857. Type, Arvicola oregoni Baclimau. 

Geographic distribution of type species. — Oregon, Washington, aud 
British Columbia. 

Geographic distrihution of suhf/enus. — The range of the subgenus 
Chilotus is coincident with that of the tyjie aud only known species. 

Fssential characters : 

Palate noimal. 

m 3 normally without closed triangles. 

m 1 with 5 closed triangles and 9 or 10 salient angles. 

m 3 with 2 or 3 closed triangles and 6 salient angles. 

Mamm;e 8. 

Plantar tubercles 5. 

Sole moderately hairy. 

Claws on hind feet longest. 

Fur short and dense. 

Slnlh— The skull of Chilotus (PI. I, fig. 8) is low and flat, the dorsal 
outline nearly straight, and the brain case not widened, as in Fedomys. 
As compared with Fedomys, the rostrum is remarkably long and slender 
in proportion to the rest of the skull. 


Bony pen ate. — The palate is normal and calls for no further remark. 

Enamel pattern in general. — The enamel folding (flg. 32) is like that 
of the tetramerodont species of Microtns, except that the back upper 
tooth is a little simplified. 

Front lower molar. — The first mandibular molar is exactly like that 
of typical Microtus. 

BacJc upper molar. — The back maxillary tooth contains a transverse 
anterior loop, two lateral closed triangles, and a somewhat lengthened 
terminal loop. The latter has at each side of its base a conspicuous 
augle, the outer one of which is often isolated as a third closed triangle. 
The tooth has six salient angles, two to each of the transverse looi)S 
and one to each of the closed triangles. 

Other teeth. — As already stated, the remaining teeth are formed 
exactly as in tetramerodont Microtus. One specimen from British 
Columbia has the lateral triangles closed in the back lower molar. 

2ramma\ — There are eight mamune, four pectoral and four inguinal. 

Feet. — Soles moderateh^ hairy from heel to tubercles; plantar tuber- 
cles five, all "well developed; claws on hind feet 
longest ; front feet not modified like those of typical 

Fur. — The fur is shorter and more dense than 
iu true Mi c rot us, hwt the modification is not car- na. 32.— Enamel pattern of 
ried so far as in Microtns {Pitymys) pinetornm. mov.ivte^th. Microtis icu- 

General remarls. — Chilotus combines the mam- " us) 01 egom. (x .) 
mic and foot pads of Arricola with the nearly typical enamel iiattern of 
Mierotus and has a form of skull peculiarly its own. In general it is 
modified in the same direction as Fitymys, but to a much less degree. 

Great stress has been laid on the form of the ear as a character of 
this subgenus. In the original description^ Baird says: 

A speciiiK'U in alcohol, from Steilacoom, received since the preceding descriiitiou 
■was prepared, is, in size, niucli as described, The ears are low, orbicular, the mem- 
brane thickened, the margins or conchal portion much inflected or incurved, like a 
half-open apple blossom, the concha being inflected all round. The antitragus is 
well developed, but rather low. The surfaces of the ear appear perfectly naked, 
with, however, a ciliatiou of long hairs toward the roots of the concha, on the dorsal 
surface. A close examination of the auricle in the dried specimen shows a i'ew scat- 
tered, very short, white hairs. 

• The structure of the ear, though in many respects similar to that of A. innetorum, 
is yet essentially different. Thus the upper and lower roots of tht; margin of the ear 

' meet auteriorlj' so as to form even a low rim to the meatus anteriorly, completely 
Inclosing the aperture ; the edge of the concha is inflected ; the region inside the 
auricle, around the meatus, naked, and the antitragus so much develoijed as to be 
capable of completely closing the meatus. In A. pinetorum the roots of the upper 
and lower margins of the ear are widely separated, by a space of a quarter of an 
inch, the space between these roots and anterior to the meatus perfectly plane ; the 
edges of the concha, or of the auricle, not inflected at all ; the inner space around 
the meatus partly hairy ; the antitragus A-ery slightly developed, not valvular, nor 
capable of closing the meatus at all. 

' Mamm. X. Am., p. 538, 1857. 


Through Mr. True's kinduess I have been able to examine one of the 
alcoholic specimens on which Baird based this description. This speci- 
men (No. 2533, from Tomales Bay, Cal.') is in good condition and shows 
most of the peculiarities to which attention was called. The thicken- 
ing of the edge of the auricle is, however, due to disease or to the 
action of the parasites which often attack the rims of the ears in the 
voles and other small rodents. The anterior base of the ear is not essen- 
tially different from the same region iu Plfymys, though the valvular 
fold is slightly more developed. It is ])robable that by means of this 
fold the meatus in Fitynn/s, as well as in most if not all of the voles, 
can be tightly clnsed. 

Subgeuus MICROTUS Schraiik. 

1798. ^icroms'Sclirauk, Fanua Boica, I, Iste Abtli., p. 72, 1798. Type l>y i-liminatiou 

Microtus terresfris Schrauk ^ Mhs arralis Pall. 
1817. Mynomes Rafinesque, Am. Monthly Magazine, II, p. 4.5, 1817. Type Mynomes 

praiensis Raf. ^^ Arvicola pcnns)jlvaiiicus Ord. 
1836. Hemiofomifs DeSolys Loiigchamps, Essai Monographique sur les Caiupagnols 

(les environs de Liege, p. 7, 1836, part (included arralis and ierrestris). 
1857. Remiotomi/s Baird, Mamra. N. Am., p. 515, 1857. 
1819. Keodon Hodgson. Ann. and Mag. Nat. Hist., 2d ser., Ill, p. 203, 1849. Type 

Neodon sikkimensis Hodgson. 
1857. Paludicola Blasius, Fauna der Wirbelthiere Deutschlauds, I, p. 3.33, 1857, part 

(included ierrestris, niralis, and rafficej)s). 
1857. AgrieoJa Blasius, Fauna der AVirbeltliiere Deutsclilands, I. ]). 334, 18.57. Type 

Arricola agrestis. 
1867. Praticola Fatio, Les Campaguols du Bassin du L^mau, p. 36, 1867, part (included 

ierrestris, nivalis, arvalis, raiiiceps, and eampestris). 
1867. Sylvicola Fatio, Les Campaguols du Bassin du L^man, p. 63, 1867. Tyjje Jrfi- 

cola agrestis. 
1890. Camjncola Schulze, Schriften Naturwiss. Vereins d. Harzes in Wernigerode, V, 

p. 24, 1890, part (included arvalis, snhterraneiis, and eampestris). 
1894. Tetramerodon Rboads, Proc. Acad. Nat. Sci. Pliila., p. 282, 1894. Type Arricola 

tetramerus Rlioads. 

Geographic distrihution of type species. — Central Europe. 
Geoiirapliic distribution of suhyenus. — Boreal region of both hemi- 
spheres, south to Mexico, northern India, and southern Europe. 
Essential characters : 

Palate normal. 

m 3 without closed triangles. 

m 1 normally with 5 closed triangles and 9 salient angles. 

m 3 normally with 3 closed triangles and 7 or 8 salient angles. 

Mamnuc, 8. 

Plantar tubercles, 6. 

Sole moderately hairy. 

Claws of hind feet longest. 

Fur not specially modified. 

Sladl. — In true Microtus (PI. I, fig. 3) the skull lacks the peculiar 
modifications found in such subgenera as Layiirus, Fitymys, Chilotus, 

' No. 2529 from Steilacoom, Wash., also mentioned by Baird, is lost. 

July, 1806.] 



and others. Withiu certain limits, liowever, tlie skull varies consider- 
ably in size and form, so that it is difficult to frame any accurate diag- 
nosis. The skull of Microtus arralis figured on Plate I represents the 
form characteristic of the great majoritj of species. One of the most 
notable departures from this type is seen in the skull of Microtus nitvdis, 
which has an unusually low, broad brain case, and flat dorsal outline. 

Bony palate. — The bony palate in the subgenus Microtus (fig. 7 A, and 
PI. II, fig. '■>) shows in its most perfect development the form which may 
be considered the normal one in the genus, since it is characteristic of 
most of the subgenera and of the vast majority of species. As this 
palate has already been described (pp. 2G-27) it is necessary here to notice 
a few departures from the type form only. In young individuals the 
sloping ridge is broader than in the adults, while in very old individuals 
it often becomes very abrupt and at the same time greatly narrowed. 
Tliese two extremes, Avhich are usually characteristic of immaturity and 
old age, occur as the normal condition in the adults of certain species. 
In Microtus nivalis the ridge is broad and fiat, while in M. agrestis, M. 
ratticeps, and most of 
the American species 
it is narrow and ab- 
rupt. Occasionally (es- 
pecially in M. ayrestis 
and M. ratticeps) the 
anterior edge of the 
interpterygoid fossa is 
encroached upon bj" 
the projecting median 
ridge. The latter, on 
the other hand, may be slightly cleft in the median line, thus fore- 
shadowing the first step in the series of changes which lead to the very 
different palate of Evotomys. 

Enamel pattern in f/eneral. — The enamel pattern in the subgenus 
Microtus (fig. 3.j) is characterized by the large number of loops and 
angles in the first lower molar and last upper molar. 

Front hncer molar. — The first lower molar normally contains a pos- 
terior transv^erse loop, five closed triangles, two of which are on the outer 
side and three on the inner side, and finally an anterior loop which is 
usually more or less deeply cut by two reentrant angles, one on each 
side of the loop, the outer of which is always the more posterior of the 
two. With these loops and triangles are usually associated nine well- 
developed salient angles, two formed by the posterior transverse loop, 
one by each of the five closed triangles, and one by each side of the 
base of the anterior loop. That part of the anterior loop which lies in 
front of the reentrant angles may develop a salient angle on its inner 
side, less frequently one on the outer side. Very rarely the Ioojd may 
be cut by a third reentrant angle. This condition occurs in adult spec- 

FlG. 33. — Enamel pattern of molar teeth, (a) Microtus {Microtus) 
arvalis ; {b) 3r. {M.) nivalis : (c) M. {M.) pennsijlvanictis ; (d) M. 
(2[.) ratticeps. (xS.) 


imens of Microtus agrestis, M. pennsylvanicus, also in the type of M. 
(Ariucola) arvieoloidcs {f\g. 35), and probably in any other species with 
the tootli formed after tLe pattern of Microtus arvalis. The other varia- 
tions in the form of the front lower molar are the result of the greater 
or less development of the reentrant angles normally present at the 
anterior end. Sometimes the fourth reentrant angle (counting from 
behind) on the lingual side of the tooth fails to meet the third on the 
opposite side. Very rarely the anterior outer triangle opens in a like 
manner into the anterior inner triangle, and the latter at the same time 
communicates with the anterior loop, thus producing a tooth like that 
normally present in Pedomys and I'itymys. liather frequently a sixth 
closed triangle is cut off from the outer basal corner of the anterior loop, 
and occasionally a seventh triangle is isolated at the inner side of the 
greatly reduced loop. 

The variations just described are purely individual and occur in the 
species having the tooth of the typical form. Two notable variations 
from this form are normally found in Microtus ratticcps and M. nivalis. 
In the former (fig. 33f?) the fifth triangle opens into the short, unindeuted 
anterior loop. There is here an actual reduction in the elements of the 
ooth, which has only eight salient angles, thus resembling the corre- 
sponding tooth in Fedomys. In M. nivalis (fig. 33t), while there are five 
closed triangles and nine salient angles, the anterior loop is small and 
crescentic, much resembling the posterior loop in the maxillary teeth 
of Eothenomys. 

Bad' upper molar. — The last upper molar is noiinally made up as 
follows : An anterior transverse loop, succeeded by three closed trian- 
gles, two smaller ones on the outer side and a larger one on the inner 
side, these in turn by a posterior loop of variable shape. The tooth 
usually contains seven salient angles, two to each of the transverse 
loops and one to each of the three closed triangles. 

Variations in the form of this tooth are numerous. Beginning at the 
anterior end where the structure is most definite, it is found that the 
first outer triangle very frequently opens into the large inner trian- 
gle, less often into the anterior loop. The second outer triangle very 
rarely opens into the inner triangle, but is rather frequently in commu- 
nication with the posterior loop. The i>osterior loop varies in form and 
size, the variations being partly individual and partly characteristic of 
species. For the present it is unnecessary to discriminate in all cases 
between the two categories. The most usual form and that found in 
the type species, Microtus arralis (fig. 33a) is an irregular crescent with 
the concavity directed inward and backward and the j)osterior tip thick- 
ened, the whole joined to the rest of the tooth nt a point on the con- 
vexity midway between the middle and the anterior extremity. This 
nearly crescentic form is usually distorted by the elongation and straight- 
ening of the anterior limb, so that the resulting shape is more like that 
of the letter J. The thickened posterior extremity of the loop is often 


extended and cut by a reentrant angle on the lingual side, so that the 
crescent is modified into the form of a rude E. Occasionally the ante- 
rior extremity of the crescent is isolated as a second inner triangle. 
The convex side of the crescent may develop a more or less prominent 
salient angle. This condition is normal in Microtus ratiiceiys and Micro- 
txs dtrotorrhiniis, but occurs also in other species. In the aberrant 
Microtus nivalis the structure of this tooth is simplified so that it is 
essentially as in Arvicola, Pedomys^ and Fitymi/s. 

Other teeth. — The first and second upper molars contain each an ante- 
rior transverse loop and, respectively, three and t^YO closed triangles. 
In Microtus agrestis, M. sihlimcnsls, M. pennsylrcmicus, M. tcrra'novce, 
and .1/. aztecus the inner edge of m2 is i)roduced into a conspicuous 
loop, which frequently becomes isolated, so as to form a closed triangle 
about half the size of the others. The European species with m2 
formed in this way have been placed in a subgenus called Agricola or 
SylricoJa, while the American species have been referred to Mynomcs 
in a restricted sense. The American species with m 2 exactly as in 
2Iicrotus arvalis have received the name Tetrameroclon. While the 
name Tctramerodon can not be used in a subgeneric sense, it is fre- 
quently convenient to speak of the voles with the enamel pattern of 
M. (irvaJis as the tetramerodont species to distinguish them from their 
pentamerodont allies. In Microtus sillimensis a supplemental triangle 
is developed in m 1 as well as in m 2. On account of this peculiarity the 
animal has been made the type of the genus or subgenus '■Xeodon.^ 
Neither Xeodon nor Agricola are worthy of recognition as subgenera 
distinct from Microtus. Their characters are of trifling importance, 
while in other species of Microtus (as, for instance, M. nivalis, M. guen- 
theri, and occasionally .1/. pennsylvanicus) intermediate conditions can 
be found. 

Mamma'. — In the subgenus Microtus the mammaj are always eight, 
four pectoral and four inguinal. Xo exceptions to this number are 

Feet. — There are six turbercles on the sole. Five of these are always 
well developed, but the sixth is variable in size, being especially large 
in M. ratticeps. The sole is always moderately hairy from heel to 
tubercles. It is never densely furred as in Vhaiomys or naked as in 
Xeojioer. The claws on all four feet are moderately developed, those 
on the hind feet always slightly larger than those on the front feet, 
the latter never specially developed for digging (cf. Pitymys). 

Fur. — The fur is moderately full and soft, neither long and silky as 
in Fhaiomys nor dense and mole-like as in Pitymys. 

General remarks. — The subgenus Microtus needs comparison with the 
groups having normal or very slightly abnormal palates: Arvicola, 
Pedomys, Pitymys, Chilotus, Fhaiomys, and Lagurus. From all the 
others it differs too widely to give rise to confusion. Lagurus is dis- 
tinguished from Microtus by the tightly closed triangles in the posterior 
16933— Xo. 12 5 


mandibular tooth, Arvicola by tlie presence of large musk glands on 
tLe sides, Fedomys and IHtymys by reduction in the numbers of both 
mamma' and jdantar tubercles, Chilotiis by reduction in the latter only, 
and I'haloniys by an increase in the number of mammte and by the 
very large claws. More extended comparisons will be found under 
each of these subgenera. 

This subgenus is the most widely and generally distributed, as well 
as the one containing the largest number of si^ecies. Although the 
si)ecies of MicrotifKe are still very imperfectly known, there is little 
doubt that the members of the subgenus Mierotus greatly outnumber 
the species of all the other genera and subgenera together. Conspicu- 
ous representatives of the subgenus Mierotus are (in the Old World) : 
Microtvs arvalis (Pall.), M. a[/restis (Pall.), 71/. raUlceps (Keys. & Bias.), 
M. nivalu (Martins), 71/. {/uentheri (Dansford & Alston), 71i. silJcimensis 
(Hodgson) 5 (in America) : Ilicrotus pennsylvanicus (Ord), 71/. terrwnovce 
(Bangs), 71/. .rantliOf/natJnt.s (Leach), 7li. ehrotorrhinus (Miller), 71/ Jongi- 
cauda (Merriam), 71/. mor/oUo^iensis (Mearns), 71/ townsendi (Bachmau). 

Subgenus ARVICOLA Laceiii-de. 

1801. ArritoJa Lact_^pecle, Mem. de I'Institut, Paris, III, p. 489, 1801 (genus). Type, 

'Arvicola anqjhibius^ = Mus terrestris Linn. 
1883. Arvicola Lataste, Le Natnraliste, Tome, II, p. 349, 1883 (subgenus). 
1836. Hemiotomys De S^lys Longchamps, Essai Mouograpbique sur les Campagnols 

des environs de Liege, p. 7, 1836, part (included arvalis and ierresiris). 
1857. Paludicola Blasius, Fauna der Wirbeltbiere Deutscblands, I, p. 333, 1857, part 

(included terrestris, niralis, and ra if icejis). 
1867. Oclietomys Fitzinger, Sitzungsber. K. Akad. Wiss. Wien, LVI, p. 47, 1867. (No 

type mentioned, but genus intended to include all the water rats of Europe.) 
1867. PraticoJa Fatio, Les Campagnols du Bassin du Leman, p. 36, 1867, part (included 

terrestris, nivalis, arrnlis, ratiiceps, and caynpestris). 
1894. Aulaconuis Rhoads, American Naturalist, XXVIII, p. 182, 1894. Type, Aitlacomys 

arvicoloides Rhoads. 

GcograpMc distribution of type species. — Northern Euroi^e. 
Geographic distribution of subgenus. — Noi'thern x^ai't of Xorthern 
Hemisphere, exclusive of America east of the Eocky Mountains. 
Essential cliaracters : 

Palate slightly abnormal. 

m 3 occasionally with closed triangles. 

m 1 normally with 3 to 5 closed triangles and 7 to 9 salient angles. 

m 3 normally with 2 or 3 closed triangles and 6 to 8 salient angles. 

Mamma^ 8. 

Plantar tubercles 5. 

Sole almost naked. 

Claws on hind feet longest. 

Fur slightly modified. 

Musk glands iiresent on sides of body. 

STculI. — The skull of the larger Old World species of Arvicola (PI. I, 
fig. 9) is nearly as large as that of Neofiber. In the American species 

July, 1896. 



(PI. I, tig'. 1) it is smaller, though considerably larger than in most 
species of jl7/cro/ Mi' proper. Aside from its large size and prominent 
ridges, the skull of Arvicola differs from that of Microtus in its broader, 
shorter brain case, more widely flaring zygomatic arches, and propor- 
tionally slender rostrum. The peculiar appearance of the rostrum is 
heightened by the fact that the incisors project more than usual. Some 
of these characters are more noticeable in the American species, though 
the latter show no cranial peculiarities of sufficient importance to sep- 
arate them subgenerically from those of the Old World. In the Amer- 
ican species the skull is usually more lightly built and less strongly 
angular than in the typical members of the genus (compare figs. 1 and 
Oofri. I). 

Bonii palate. — The bony palate is usually normal, but ocasionally 
the median sloping ridge is divided in the median line, so that the 
iuterpterygoid fossa is hastate anteriorly (PI. Ill, fig. 7). This condi- 
tion occurs most frequently in the Ameri- 
can species, but even among these it is 

Enamel pattern in (jeneral. — The enamel 
pattern in iy\)ic,2i\ Arvicola (tig. 34Z>) is char- 
acterized by the great reduction in the 
number of closed triangles and salient 
angles in the front lower molar and 
back upper molar. In these peculiarities, 
though closely approached by Pitymys, 
Pedomys, and Phaiomys, it presents the 
extreme conditions found in the genus. 
The third lower molar shows the tendency 
to closure of the lateral triangles charac- 
teristic of all the larger members of the genus. The pattern of enamel 
folding in the molar teeth of the American species of Arvicola (fig.olrt) 
is, on the other hand, exactly like that of the tetramerodont species of 
the subgenus Microtus (e. g., Microtus arvalis and most of the western 
American species). 

Front lower molar. — In the typical species the simplification in the 
structure of the teeth is carried furthest in the first lower molar. This 
tooth normally contains a i)osterior transverse loop followed by three 
closed triangles (one on the outer side, two on the inner side) and a 
terminal transverse loop which is deeply constricted in the middle. 
Each transverse loop forms two salient angles and each lateral triangle 
one, making seven in all. Deviations from this form are very rare. In 
one or two specimens I have seen a fourth triangle isolated on the outer 
side, thus producing a tooth much like the corresponding one in Micro- 
tus {2Ilcrotus) ratticeps, a species which has the last upper molar very 
complicated in structure. The front lower molar in typical Arvicola 
differs from that of the other groups in which it has only three closed 
triangles in the reduced number of salient angles — seven instead of 

Fig. 34.— Enamel patteru of molar teeth, 
(a) Microtun (Arvicola) macropus ; 
(h) M. (A.) terrestris. (x5.) 


uiue. Since this tootli in the Americau species lias the same structure 
as in Microtus arralis, no special description is necessary. 

Bade upper molar. — In the typical species the last upper molar has 
an anterior transverse loop, a closed triangle on each side, and a very 
short, simple terminal loop. With these loops are associated six salient 
angles, two on each of the terminal loops and one on each closed triangle. 
Rarely the posterior terminal loop is reduced by the isolation of the 
outer basal angle as a third closed triangle, but this seldom happens, 
while the resulting form of tooth is quite difierent from that found in 
any member of the subgenus Microtus except the aberrant Jf. nivalis. In 
the American species this tooth is formed exactly as in Microtus arralis. 

Mammw. — There are eight niammie in Arvicola, as in Microtus. 

Feet. — In Arvicola the soles are very sparsely haired or almost naked 
between the tubercles and the heel. 

The tubercles are only five in number, as the small one which in 
Microtus lies midway between the large proximal tubercle and the base 
of the fifth toe is absent. Claws moderately developed, those on hind 
feet slightly the larger. 

Fur. — The fur is close, dense, and long, the under fur especially thick 
and woolly. It thus resembles the fur of Neofiher^ though the modifica- 
tion is not carried so far as in the latter. 

Miscellaneous characters. — The species of Arvicola are provided with 
a large musk gland on each side of the abdomen. These glands lie 
immediately in front of the hind legs and are very conspicuous in alco- 
holic specimens. In a half-grown male Microtus terrestris from St. 
Petersburg, Russia, each gland is 13 mm. long by 6 mm. wide. They 
are regularly oval in outline, the long axis parallel with the long axis 
of the body. The surface, which is slightly raised above that of the 
surrounding skin, is closely and irregularly wrinkled, and has much 
the appearance of very finely honeycombed tripe. Each gland bears a 
sprinkling of fine hairs much shorter than the fur, but at first sight 
appears to be naked. In dried skins the positions of the glands are 
indicated by tufts of grease-soaked fur. 

General remarks. — The subgenus Arvicola is distinguished from all 
other groui)S with similar enamel pattern or with like numbers of 
mammte and foot pads by the presence of the large glandular masses 
on the sides of the body. The species are all water rats, and, with the 
exception of Microtus [Neojiber) allem., they considerably exceed the 
other members of the genus in size. 

Although this subgenus is now for the first time recorded from 
America, at least three species of Arvicola inhabiting the western 
United States have been described within the past five years. These 
are 3[ierotns macropus (Merriam), M, arvicoloides (Rhoads), and M. 
principalis Rhoads. Microtus macropus was supposed to be "one of 
the western members of the subgenus or section Mynomes,^' that is, a 
tetramerodont Microtus.^ Microtus arvicoloides was made by its descri- 

' North American Fauna No. 5. p. 60, July, 1891. 

July. 1896] SUBGENUS NEOFIBER. 69 

ber the type of a new genns, Aulacomys,^ while M. principalis, closely- 
allied to botli M. maeropns and M. arvicoloides, was referred by the same 
author to true J/icro/M.v.'- This coufusion arose from the fact that the 
subgeiieric aud generic determinations were based chiefly on dental 
characters. Hence Mierotus maeropns and M. principalis were naturally 
considered members of the subgenus Mierotus, since both have the 
enamel pattern characteristic of the tetramerodont species of that group. 
The teeth of the type and only kuown specimen of Mierotus arvico- 
loides, on the other hand, show certain characters which, although clearly 
abnormal, led to an entire misunderstanding of the animal's true rela- 
tionships. The first of these abnormal characters, and the one which 
suggested the name Aulaeoniys, is seen in the upper incisors. Each of 
these has a narrow longitudinal median groove. They can not, however, 
be considered as entitling the species to generic rank, since similar 
though fainter grooves are occasionally found in almost any species of 
Mierotus, while they are absent in the vast majority of specimens of 
'■Aulaeomys.'' The second abnormality in the type of Mierotus arvico- 
loides is in the form of the front lower molar. This tooth (fig. 35) has 
two reentrant angles on the outer side of the anterior 
loop instead of one as usual in Mierotus. The supi)le- 
mental reentrant angle, like the grooves in the incisors, 
is purely an individual character, which may crop out ^^^"' ^^--^^J^iormai 

'■ "^ ' ^ L front lower molar 

in any species of Mierotus, with the front lower molar of type specimen of 
formed as in M. arvalis, and which is absent in all the 'Mdacomys- arvico- 

• > I 7 ITT loides. (x4.) 

other thirty or more specimens ot ^ Aulaeomys^ that 1 
have seen. The subgenus Aulaeomys if retained as distinct from Arvi- 
eoJa must rest on characters of enamel pattern alone, since in all other 
peculiarities it agrees perfectly with the latter. The difterences in 
enamel folds are rather considerable, since ^Aulacomys^ has the highly 
complicated pattern of true Mierotus, while the species of typical Arvi- 
cola have the simplest pattern of any known. While it seems highly 
inadvisable to base subgeneric divisions on such characters, the deci- 
sion rests on purely individual judgment. 

In the Old World numerous species and subspecies are probably 
confused under the name ^Arvieola amphibius.'' Mierotus musignani (De 
Sclys Longchamps) and M. monticola (De Selys Longchamps) appear to 
be especially distinct from ^1/. terrestris (Linn.). 

Snbgeuus NEOFIBER True. 

1884. Xeqfiber True, Science, IV, p. 34, July 11, 1884 (full genus). Type Neofiher alleni 

1891. Neofiher Merriam, North American Fauna, No. a, p. 59, July, 1891 (snl)geuus). 

Geoyraphical distribution of type species. — Florida. "Doubtless a com- 
mon animal in favorable localities throughout the State." (Chapman.) 

'American Naturalist, XXVIII, p. 182, February. 1894. 
^American Naturalist, XXIX, p. 940, October, 1895. 


Geographical distrihutioyi of suhgenvs. — The range of the subgenus 
Neofiher is the same as that of the tyi)e and only known species. 
EssentUd characters : 

Palate abnorm:il. 

m 3 with all triangles closed. 

m 1 with 5 closed triangles and 9 salient angles. 

m 3 with 2 closed triangles and (3 salient angles. 

MamniiTB 4. 

Plantar tubercles ;">. 

Sole naked. 

Claws on hind feet longest. 

Fur highly modified. 

SJx-idl. — The skull of Xeo fiber is characterized by its large size, great 
dei^th through the frontal region, and conspicuous development of 
postorbital processes. The ratio of fronto-palatal depth to basilar 
length is about 41 in Xeojiher, while in true Microtus it is onlj^ about 
35. As the occiput in Xeojiher is not correspondingly high the dorsal 
outline of the skull curves gently and regularly from front to back, 
with the higliest point Just behind the orbits. When viewed from 

above the skull of Neofiber differs from that 
of Microins chiefly in the larger scpiamosals, 
smaller parietals and interparietal, and in 
the sharp-pointed postorbital processes. 
The latter project over the orbital cavity 
as square-cornered shelves, which are espe- 

FiQ. S6.— Enamel pattern of molar cially UOticeablC whcil vicWcd from bclOW. 

teeth, Microtus (Xeofiber) aiieni. Palate.— T\\& bouy pahitc iu Xcofiber (PI. 

II, fig. 9) differs widely from that of MicrotuSy 
and exactly resembles that of Fiber (p. 72). 

Enamel liattem in general. — In general the enamel pattern of Xeo- 
fiber (fig. 36) is characterized by a tendency to reduction in the number 
of angles in the variable teeth and to the tight closure of all triangles. 
The latter peculiarity gives the teeth the greatest possible strength. 

Front lower molar. — The first molar in the lower jaw exactly resem- 
bles the corresponding tooth in Microtus except that the anterior loop 
is rather shorter than in the typical members of that subgenus. In 
one specimen (jS"o. 23153, U. S. Nat. Mus.) the anterior loop has two 
indentations on the outer side, thus suggesting Anaptogonia. 

Back upper molar. — The third maxillary tooth is like that in the 
subgenera Fitymijs, Fedomys, Fhaiomys, Chilotus, and typical Arvicolafi 
as it has only two closed triangles and six salient angles. 

Other teeth. — The back lower molar has all the triangles tightly closed, 
in this respect differing from all other subgenera except Lagnriis. 
Closed triangles are sometimes formed in the third lower molar of 
almost any of the larger voles, but Xeofiber awd Lagurns are the only 
groups in which they are always present. (Outside the subgenus 
Lagurns, most of the known species of which are small, the tendency to 

July, 1896.] GENUS FIBER. 71 

closure of tlie triangles in this tooth increases with the size of the 
animals until in such large species as Microtus alleni and the niembers^ 
of the genus Fiber they are always tightly closed. Microtus terrestrisj. 
the only species approaching ^1/. alleni in size, has closed triangles in 
m o very often, while in one specimen the tooth is formed exactly as in 
Xeofiber. M. 'princiimlis Rhoads, another large species, also rather 
frequently shows closed triangles in this tooth. The incisors, like those 
of Fiber, are short, broad, and very strong, in this respect reaching the 
opposite extreme from that attained by ^Anlacomy.s.^ 

2famm(c. — Ajiparently the number of mamm.Te in Neojiber has never 
been stated in print. Mr. Outram Bangs writes me, however, that he 
found four inguinal teats in an adult female Microtus alleni which he 
took in Brevard County, Fla., during February, 1895. 

Feet. — Soles wholly naked, foot pads five, as in Arvicola; claws on 
hind feet longest. 

Fur. — The fur is modified to meet the requirements of an aquatic life 
in the same way and to almost the same extent as in the genus Fiber. 
The under fur is exceedingly thick, woolly, and dense, while the longer 
hairs are very glossy and lustrous. This condition is suggested in 
Arvicola, where, however, the moditication is not carried so far. 

Miscellaneous characters. — Whether Xeofiber is i^rovided with musk 
glands like those of the other water rats is at present uncertain. Col- 
lectors have failed to notice them, but they might easily escape detec- 
tion in the thick fur unless specially searched for. The only alcoholic 
specimen that I have examined is not iwW grown. This shows no trace 
of the glands even when the skin of the sides is raised and examined 
from beneath. 

General remarks. — In Xeofiber are combined the mandibular enamel 
pattern of Lagurns with the maxillary enamel pattern and external 
characters of typical Arvicola, complicated by a reduction in the num- 
ber of mammae as in Pedomys and Pitymys. 

Genus FIBER Cuvicr. 

Fiber Cnvier [Tabl. Ele'm. de I'Hist. Xat. des Auiin.. p. 141, 171»8], Lemons d'Auat. 
Comp., I, tabl. I, 1800. Type Castor zihethicus Liuii. 

Geographic distribution of type species. — Xorth America iu)rtli of the 
southern border of the United States. 

Geographic distribution of genus. — The range of the genus Fiber is 
essentially the same as that given for the type species. 

Essential characters : 

Upper incisors witli antorior faces smooth. 
Lower incisors with roots on outer side of molars. 
Molars rooted. 

Enani(d pattern characterized by approximatf e(iuality of reentrant angles on 
outrr and inner sides of molars. 
Feet modified for swimming-. 
Tail flattened laterally. 



[No. 12. 

Fig. 37.— Skull of Fiber zibethicus 
(natural size). 

Sl-ull. — The skull (fig. 37) differs very slightly from that of Microtus 

except that it is cousiderably larger than in any known species of the 

latter, and has a proportionally longer ros- 
trum. The bony palate (PI. II, fig. 12) re- 
sembles that of the species of Altk-oUi and 
J^eofiher in the extension forward of the in- 
terpterygoid fossa and suiipression of the 
sloping part of the median ridge. The pos- 
terior border is thus squarely cut off imme- 
diately behind the lateral bridges. A vestige 
of the sloping ridge usually persists in the 
form of a median spine projecting into the 
ill terpterygoid space. The skull of Fiber is 
peculiar in the expansion of the squamosals 
on the dorsal surface of the skull at the ex- 
pense of the x)arietals. The postorbital proc- 
esses of the squamosals form prominent 
triangular projections closely resembling 
those of Keofiher. The interparietal is 
squarish in outline and usually somewhat 

longer transversely than antero-posteriorly. 

Teeth. — The molars are all rooted in the adults (fig. 38), though the 

roots on the back lower tooth are usually 

less w^ell developed than those on the 

others. Otherwise the teeth are exactly 

as in MicrottLS. The enamel pattern 

(fig. 30), most closely resembles that of 

Microtus [Xeofiber) aUeni, but differs in 

the larger anterior loop of the first lower 

molar. This loop is cut by two deep 

reentrant angles, which often isolate 

two additional closed triangles, making 

seven in all. 
Feet. — The feet are large and so formed 

that they can be turned edgewise when carried forward, thus producing 

the least possible resistance to the water Avhile the animal is swimming. 

This character is, however, to a certain ex- 
tent, reproduced in the more aquatic species 
of Microtus and can not be considered diag- 
nostic of Fiber. 

Miscellaneous characters. — Thetail is strong- 
ly compressed laterally, making an effective 
rudder. The peculiar form of the tail is 
scarcely noticeable in the young even when 
large enough to leave the nest, but develops 

rapidly as the animals increase in size. 

The fur of the species of Fiber is highly modified to produce a 

Fig. 38.— Sick' view of molars, Fiber zibeth- 
icus. (X li.) 

Fig. 39.— Enamel pattern of molar 
teeth, Fiber zibethicus. (x 2^.) 

JvLY, 1896.] GENUS BRAMUS. 73 

tliorougiily waterproof covering. The long Lairs are remarkably close 
and glossy, wliile the under fur is very dense. In the character of the 
fur Fiber is approached by some of the aijuatic species of Microtus, 
esi>ecially M. (Arricola) terrestris and M. (Xeojiher) alleni. 

General remarls. — Fiber is very closely related to Microtu.s, from 
which it is distinguished by its tlattened, rudder-like tail, and rooted 

In addition to the well-known musk rat, Fiber sibethicus, three forms, 
whose interrelationships are not yet understood, are uow recognized. 
These are: Fiber zibethicns paUidns Mearns, F. obsciirus Bangs, aud 
F. riralicins Bangs. 


Three extinct rodents referred by authors to the family Microtinec 
have been made the types of superspecific groups. Two of these, from 
the Postpliocene of Pennsylvania, are subgenera of TIf /cro/».sf; the third, 
from the Quaternary i)hosphorites of Trara de Nedroma, near Ain- 
Mefta, Tunis, is a genus of doubtful affinities. As these groups are 
necessarily based almost wholly on dental characters, it is impossible 
to describe them in tlie same manner as the living genera and sub- 
genera. It is furthermore impossible to form a clear judgment of the 
validity of the groups in question without examination of the actual 
specimens. Such examination I have not been able to make. Hence 
the few conclusions here reached are necessarily incomi»lete and 

The genus Bramus Pomel (Comptes Rendus, Paris, CXIY, p. 1159, 
1892), from the Quaternary Phospliorites of Tunis is represented by 
one species, Bramus barbarus Pomel. Of this animal the mandible and 
the teeth of both jaws are known. ^ These show characters which sug- 
gest the Casioridce. 

'Les molaires montrent sur leur couroiine la structure de celles flu r<ifc d'eau, dont 
dies out ii peu pres les diuiensious. Ou y voit une double serie d'eucoches et d'angles 
alteruatifs qui oorrespoudeut lateralemeut a des aretes saillautes, 5 eu dedans et 4 eu 
dehors a la premiere dent iuferieure, 3 de ehaque cote aux deux suivantes iuferieures 
et aux deux premieres sup^rieures et 2 seulement avec arete post^rieure a la troisieme 
d'en-liaut. Chez Arvkola cette derniere est beaucoup plus conipliqu^e, ayant trois 
paires d'aretes et un fort contrefort posterieur. Dans la fossile les sillons sout moins 
profonds, a angles moins A-ifs, ainsi qne les aretes, et les lignes d'email ne se soudeut 
pas d'un cote a I'autre de la couronne, ainsi qu'elles le font chez Arvicola ; il eu rosulte 
nue lign. ni^diane continue de dcntiue sur la couronne, au lieu d'une s^rie alternative 
de petits triangles hordes d'email; de sorte que la dent (V Arvicola est, en realite, 
formee de deux rangces de prismes distiucts, tandis que celle du fossile est nn prisme 
unique fortemcnt sillonne sur les cotes. II y a plus de ressemblance avec certains 
Gerbilles, qui out cepeudant les molaires bien moins prismaticjues et antrenient 

Les molaires des Arvicola ne sent jamais radiculees sauf peut-ctre chez les tres 
vieux sujets. Dans notre fossile, je les ai trouvees toujours radiculees des qu'elles 
percent ralvoole dentaire; leur fut, quoique franchement prismatique, est bieu moins 
allonge. Ses deux racines, a la vdrite, sout tres longtemps ouvertes a leur extremite, 


The iiiolar.s, which are rooted, do not differ essentially in enamel pat- 
tern from those of living species of 2ficrotus, except that the back 
npper tooth is remarkably simple in structnre, and the reentrant angles 
in all the teeth are so shallow that the triangles are open. While the 
front lower molar has nine salient angles, as in tyi^ical Mkrotus, the pos- 
terior maxillary tooth has only four and a very small terminal looj). 
The author remarks that the open triangles give the teeth of Bramns a 
resemblance to those of some of the Gerhiilida', but this likeness must 
be very superficial. The most remarkable character of Bramus is the 
form of the mandible, Avhich is like that of Castor and very unlike that 
of any of the ]\[uri(la'. It is probable that Bramus is the tyi3e of a group 
differing too widely from any of the recent Mlcrotimv to be united with 
them in one subfamily. 

The subgenera. Imdelta and Anaptogonia were described by Prof. 
E. D. Cope in 1873 (Proc. Amer. Philos. Soc, XII, p. 87). Both are 
based on teeth from the Postpliocene deposit in Port Kennedy Cave, 
Pennsylvania. Anaptogonia is very different from any of the living 
subgenera of Microtus — so different that, as Professor Cope suggests, 
it may be eventually recoguized as a distinct genus. Isodelia, on the 
other hand, is hardly separable from Fitymys, since the characters 
pointed out as diagnostic of the two groups are not beyond the range 
of variation among the species of one subgenus. 

The original description of Microtus hiatidens, the type of the sub- 
genus A«fl^^O(/oj(«V/, is as follows: 

Represented by several molar teeth. These are several times as large as the teeth 
occupying the same position in any of the species alreadj^ mentioned in this essay, 
and suggest the genus Fiber. The distinctive features of the latter are the com- 
pressed, oar-lilve tail, with rooted molars, and it is evident that the relationship of 
this species is not to it. Perhaps it is neither an J r/coZa (sic.) l^Microtits'] nor a 
Fiber, since it diifers in the structure of the teeth from the known species of both. 
None of the triangles are isolated, but are connected by a narrow striii of dentine, 
which is narrow posteriorly, but widens anteriorly until it opens out into the ter- 
minal loop. Thus the sectional nsmie Anaplof/onia maybe found ultimately appli- 
cable to a separate genus. The separation of the enamel folds merely carries to the 
highest degree that which is seen in the anterior part of the tooth of ^. sigmodus. 

In the inferior m 1 the triangles, which do not open on one side to the anterior 
loop, are IJ, then one on each side, and the short, wide, terminal loop, which is 
bilobed or emarginate in the middle of the end. The ridges, Avhich are very promi- 
nent and acute, are, therefore, i ; at the extremity there are two short ones, between 

mais elles sont de bonne heure parfaitement distinctes I'uue de I'autre. La troisifeme 
molaire iuferieure, un peii plus arqu^e que dans ArvicoJa, ne descend pas a la face 
interne de Tincisive, nuiis reste tout h fait au-dessus, et ses racines seules s'insiuueut 
un peu lat^rulement sur cette face. 

L'os maudibulaire presente des diltereuoes beaucoup plus importantes. Son 
apophyse angulaire, restaut presque dans le plan general de l'os, ne fait en ai'riere 
qu'uue l(5gere saillie bordaut la branche montante, (ju'elle suit tres haut sous le 
condyle pour se terminer en simple petit cran. II y a une grande analogie de forme 
avec ce que I'on voit chez les Castors. Dans Arvicola, au contraire, I'apophyse 
angulaire est basse et se rejette oblitiuement en arriere en forme de cuilleron forte- 
ment crocliu et tordu, rappelant du reste, sauf cette torsion la disposition de cette 
partie chez les autres Murides. 


■which a third and more promiuent oue rises a little below the grinding snrfaec. A 
little more attrition would give the distal loop a trilobate outline, and a little more, 
an acuminate one, from the loss of the lateral angles; finally the median ridge 
disappears also. 

Tbe subgenus Isodelta is cousidered by Professor Cope to show au 
exaggeration of the characters of Pitymy.s. Tbe type and only known 
species, Microtus .sjyeothen, is described as follows: 

This species is represented by the entire dentition of the left ramus mandibuli, 
with a few fragments of the adjacent bone. As already pointed out, its characters 
entitle "it to rank as a listinct section of the genus. Thus, the triangles of the inner 
side of the anterior inferior molar are one less than in any species of the section 
Anicola l = Mic7-otus']. The anterior loop presents two well-mai-ked angular basal 
areas, while its terminal portion is regularly rounded. « * * That this is not one 
of the species of Plti/miis, in which the basal lobe of the anterior trefoil has been cut 
off by unusual inflexion of the enamel angle, is demonstrated by the structure of the 
second molar, Avbich is precisely that of typical Arvicola [== J/)c/o/hs], all the tri- 
angles from the posterior being isolated and alternating, producing the formula 
1 1 0. The third molar has the usual formula, 1-1-1, the posterior two lobes being 
crescentic, the anterior trapezoid. 


In a paper entitled ' Tbe Vertebrata of tbe Forest Bed Series of 
Norfolk and Suftblk' ^ Mr. E. T. Newton describes nanierous remains 
of a niicrotiue rodent with well-developed fangs on tbe molar teeth and 
intermediate in size between Arvicola amphibius [ = Microtus ferres- 
tris] and tbe smaller voles. This animal, which Mr. Newton named 
Arvicola intermcdius, has been recently referred to the genus Phena- 
comi/s.- While the species is certainly not an Arvicola [=Microtus], it 
appears to be equally far removed from Phenacomys and ])robably from 
Evotomys and Fiber also. The teeth are described as follows: 

I have now before me about 40 vole jaws from the " Forest Bed '' which, altliough 
dithering somewhat in size, agree precisely in the patterns of their teeth. Only 14 
of these allow the bases of their teeth to be seen, but nine of these have more or 
less distinct fangs; the other five have no fangs, but are most probably immature, 
as in other particulars they agree precisely. I have likewise some hundreds of iso- 
lated molar teeth, and a very large proportion of these are fanged. * * * The 
great variation in the size of these fanged teeth would lead one to suspect that they 
represent more than one species, but there are no sufficient grounds for their separa- 
tion. * * * The patterns of the grinding teeth are so nearlj^ like those of J. 
(unphihins as scarcely to need description, and it is on the presence of fangs in the 
adult that the chief distinction between the two species I'ests; nevertheless, there 
are a few points deserving of notice. In one of the largest and most perfect man- 
dibular rami (figs. 3, 3a) the entire molar series, measured along the alveolar margin, 
180.33 inch (8.5 mm.). Mr. Reeves's specimen, from the Bramertuu Crag (tig. 12), is a 
little larger. The first molar has the five inner and four outer angles alternating, 
but the anterior two are not so prominent as is usually the case in A. ampliihins, and 
the front of the tooth is somewhat more rounded (fig. 3/^). In the Bramerton jaw 
this is especially the case (fig. 12a). All the anterior lower teeth from the "Forest 
Bed" series which I have seen have the infoldiugs of the enamel behind the ante- 
rior prism less deep than in those examples of A. anipMhius which I have been able 

'Memoirs of the Geological Survey, England and Wales. London, 1882. 
= Nehring, Naturwissenschaftliche Wochenschrift, Xr. 28, July 15, 1894. 


to examine; aud hence tlie dentinal portion of tlie anterior prism is more widely 
continent with the second inner and outer prisms; it is, in fact, an exaggeration of 
the form indicated hy Blasins, tig. 186 (Slingethiere Deutschlands, p. 345). The second 
molar has three inner and three outer angles alternating. The third molar has like- 
wise three inner and three outer angles, hut the alternation of the prisms is so slight 
that the opposing inner and outer prisms are confluent. ^ * '^ I am not acquainted 
with any specimen which shows the three upper molars in place, hut Mr. Savin has 
two specimens which retain the first and second upjier grinders (fig. 1), and Mr. 
Reid hag obtained several isolated specimens of last upper molars. The anterior 
upper molar (tig. la) has three inner and three outer angles alternating; the second 
tooth has three outer and two inner angles alternating. The third upper molars 
vary somewhat; in some only three inner and three outer angles can he counted 
(fig. 2a), while others have three inner and four outer angles. The widely confluent 
character of the front prisms of the lower anterior molar is repeated in these hinder 
upper ones. It will he noticed that in all Blasius's figures of the last upjier teeth 
(I.e., p. 345) the anterior inner fold (cement space) and the two anterior outer 
folds extend across the teeth and meet the enamel of the opposite side, while in 
one case (fig. 190) the two inner folds pass across. Now, in most of the teeth under 
consideration it is only the one anterior inner and one anterior outer fold which pass 
across; in some instances the second outer fold passes farther inward, hut I do not 
think that in any instance it touches the opposite side. 

The teetli of '■Arvicola'' intermedius dift'er in nuuierous characters 
from tbose of Fiber, Uvotomys, aud Phenacomys, the only known living 

microtines witb rooted molars. The small 
size of the remains and the simple struc- 
ture of the first lower molar are sufficient 
to indicate that the animal is not closely 
related to Fiber, although the chara(;terof 
the roots of the molars, as shown in tigs. 

TlG.40.-Enamelpatternofmolarteeth, 5 g ^^,j(^| 7 ^^f p|^ XIII, is StrOIlgly SUggeSt- 

Arvicola intennedius. From Newton. ^ ^ <=< 

ive of this genus. The figure of the inner 
side of the lower jaw (PI, XIII, fig. 3ff) suggests that the posterior molar 
is strongly displaced by the shaft of the incisor, as in Microtus. This 
character alone would show that the species is neither an Evotomys nor 
a PhenacomyH ; but the peculiarities of the enamel pattern furnisli addi- 
tional reasons for its exclusion from these genera. The enamel pattern 
(fig. 40) is, as Mr. Newton remarks, almost exactly like that of Mierotns 
terresiris (see fig. 34). It thus lacks the deep reentrant angles on the 
inner side of the lower molars characteristic of Phenacomy.s, and the 
rounded salient angles aud opposite triangles characteristic of Fvo- 
tomys. The last lower molar in particular is noticeably different from 
that of either Evoiomys or PJienacomy.s. '■Arricolu ' intcnuediu.s is appar- 
ently still further removed from Erotomys by the large size of the teetli 
as compared with the jaw. There can be little doubt that the animal 
represents a genus distinct from any now living.^ In the absence of 
si)ecimens. however, nothing would be gained by an attempt to name 
aud define the group. 

' Whether the rooted microtine teeth mentioned hy Nehring (Naturuissenschaftliche 
Wochenschrift, Nr. 28, .Tuly 1894) and hy Forsyth Major (Atti 80c. Ital. Bci. Nat., 
XV, p. 389) belong to animals congeneric with Jri-icola intermedius is purely a matter 
of conjecture. 


[Synonyms in italics.] 

i Aijricola. 11,10,21,62. 
i Alticola, 9, 17. 19, 23, 5l'-54. 
I Alviccola, 15. 
' Arnmomys, 15, 58. 
( Anaptogonia, 17, 74-75. 
1 Antelioniys, 9. 
Arctomys, 13. 
Arvicola, 9, 14. 
Arvicola, 14. 

atiiphibuis, 14. 
intermedins, 75-7t) 
Arvicoiince, 8. 
Avlacomys, 18, (59. 

Bainl, classification adopted, by, 21-22. 
Blanlord, classification adopted by, 23. 
Blasius, classification adopted by, 21. 
Bony palate, 26-28. 
BorioUcon, 17, 38. 
Brachyurus, 15. 
Bramus, 18, 73-74. 

barbarus, 73-74. 
Biiclmer, opinion on taxononiic value of enamel 

pattern, 25. 
Camjiicola, 18, 62. 
Castor, 12. 

Chilotus, 9, 16, 19, 22, 60-62. 
Coues, classification adopted by, 22-23. 
Cuniculns, 12. 
Cuniculus, 16, 38. 
De Selys-Longcliaiiips, classification adopted Tiy, 

Dicrostonyx, 8, 9. 10, 38-40. 

ton^uatus, 9, 40 
Enamel pattern, 25. 
Eothenomys, 9. 45-47. 
Eremiomyg, 17, 50. 
Evotomys, 8, 9, 17, 22, 28, 42-44. 
californicus, 44. 
fuscodorsalis, 44. 
galei, 44. 
gapperi, 44. 
glareoliis, 44. 
idahoensis, 44. 
occidentalis, 44. 
rufocauu.s, 44. 
rntilus, 9, 44. 
Fatio, classification adopted by, 22. 
Fiber, 8, 9, 14, 71-73. 
obscurus, 73. 
rivalicius, 73. 
zibethicus, 9,71-73. 
Glis, 12. 
Glis, 12, 13. 

Hemiotomys, 16, 19, 20, 22, 62. 
History of classifications, 19-24. 

Hyperacrius, 9. 

Hypudceus, 14, 21, 22. 

Interpterygoid fossa, 27. 

Isodelta, 17, 74-75. 

Keys, 28-32. 

Lagomys, 13. 

Lagurus, 9, 16. 49-51. 

Laiiox>odumys, 18, 24, 57. 

Lataste, classification adopted by, 23-24. 

Lateral bridges, 27. 

Lateral grooves, 27. 

Lemuii, 8. 

Lemmings, 8. 

Lenimus, 8, 9, 13, 36-37. 

lenimus, 9. 37. 

nigripes, 37. 

obensis, 37. 

.scliisticolo7-, 37. 
5VIarinota, 13. 

Maxillo-palatine siituri'. 26. 
Microti, 8. 

Microtina?, geographic distribution, 9-10. 
habits, 10-11. 

lists of genera and subgenera, 9. 
subfamily and divisions, 8-9. 
Microtus, 8, 9, 14, 19, 20, 21, 24, 44-71. 

agrestis, 66. 

albicauda, 54. 

alleni,9, 69-71. 

arvalis, 9, 62, 66. 

arvicoloides. 08-69. 

austerus, 9, 55-.56. 

blanfordi. 54. 

blythii, 9,57.58. 

braudti, 58. 

characters on which present classifica- 
tion of subgenera is based, 24-28. 

chinensis, 9, 47-49. 

chrotorrhinus, 66. 

curtains, 51. 

fertilis, 9, 54-55. 

fuscus, 58. 

(genus), 44-15. 

guentheri, 06. 

hiatidens, 74-75. 

iagurus, 9, 49, 51. 

longicauda, 66. 

Inteus, 49, 51. 

macropus, 69. 

mandarinus, 58. 

melanogaster, 9, 45-47. 

middendortfi, 24, 49. 

mogollonensis, 66. 

monticola, 69. 




Microtiis musiguaui, 09. 

nivalis, GO. 

oregoni, 9, 60-C'J. 

pallidas, 51. 

liaunerriruus, 51. 

peunsylvfinicns, 66. 

(peutamerodont t>i)ecie.s), 65. 

piueturuni, 9,58,59. 

principalis, C9. 

przewal-sliii, 51. 

quasiater, 60. 

ratticeps, 66. 

roylii, 54. 

.savii, 60. 

sikkiiuensis, 65, 66. 

speotlien, 75. 

stolifzkanii.s, 9,52,5-1. 

stradiej-i, 54. 

.straucbi, 58. 

(subgenus), 62-66. 

subterraneus, 60. 

terrsenova?, 66. 

terre.stris, 9, 66, 69. 

(tetramerodont species), 65. 

townsendi, 66. 

wyunei, 55. 

xantliognatlius, 66. 
Micruriis, 17, 58. 
Mictomys, 9, 18, 35-36. 
Misothermus, 16, 38. 
Mu8, 11. 

amphibins, 11. 
terrestris, 11. 
Mijnomes, 15, 19, 20, 21, 23, 62. 
Myocastor, 13. 
Myodes, 15, 20, 24. 
Myolemmus, 16, 38. 
Myotalpa, 8. 
Myotalpiuae, 8. 

iVeodow, 16, 19,23,62,65. 

Neofiber, 9, 17, 19, 69-71. 

Nomenclature, 11-19. 

Ochetomys, 17, 66. 

Ondatra, 13. 

Palatine bone, 27. 

Paludicola, 17, 19, 21, 23, 62. 

Pedouiys, 9, 16, 19, 22, 55-56. 

Pentamerodout species of Mierotus, 65. 

Pbaiomys, 9, 17, 56-58. 

Pbenacomys, 8, 9, 18, 40-42. 

celatus, 42. 

intermedius, 9,42. 

latimanus, 42. 

longicauda, 10, 42. 

oramontis, 42. 

orojihilus, 42. 

truei, 42. 

ungava, 42. 
I'incmys, 16, 58. 
Pitymys, 9, 15, 19, 22, 24, 58-60. 
Praticola, 17, 22, 62. 
I'aaminomys, 15, 58. 
Siphneince, 8. 
Sijfhneus, 8. 
Sylvicola, 17, 22, 62. 
.Synaptomys, 8, 9, 16, 32-36. 

cooperi, 9, 35. 

dalli, 36. 

fatuus, 35. 

helaletes, 35. 

innuitus, 9. 

(subgenus), 34-36. 

truei, 36. 

wrangeli, 36. 
Terricola, 17, 58, 62. 
Tetramenidon, 18,62. 
Tetramerodont species of JUiCrotus, 65. 
Voles, 8. 


[Enlarged cmo aiul om-half times.! 

Fig. 1. Microius {Arricola) macropny. AVood Rivt-r, Idaho. 
(No. 31630, U. S. Nat. Mus.) 

2. Microtus (Pilymys) jjinetoriiiu. Wasliiugton, D. C. 

(No. 30332, U. S. Nat. Mns.) 

3. Microtus (Microtus) arralis. Cepiu, m^a.. Esszek, Slavouia. 

(No. 3035, collectiou of Gerrit 8. Miller, jr.) 

4. Evotomys. Portland, N. L)ak. 

(No. 35835, U. S. Nat. Mus.) 

5. Phenacoviys oramontls Rlioads. Mount Baker Range, British Columbia. 

(No. 3562, collection of Gerrit S. Miller, jr.) 

6. Lemmus nigripes. St. George Island, Alaska. 

(No. 42680, U. S. Nat. Mus.) 

7. Microtus (Lagurus) curtatus. Reese River, Nevada. 

(No. 32498, U. S. Nat. Mus.) 

8. Microtus (Chilotus) oregoni. Sinnas, British Columbia. 

(No. 4160, collection of Gerrit S. Miller, jr.) 

9. Microtus (Arricola) terrestris. Braunschweig, Germany. 

(No. 1934, collection of C. Hart Merriam.) 

10. Microtus (AUicola) alhicauda. Type. Braldu Valley, Ballistan. 

(No. 36916, U. S. Nat. Mus.) 

11. Microtus (Hyperacrius) fertilis. Pir Panjal Range, Kashmir. 

(No. 35511, U. S. Nat. Mus.) 

12. Synaptomys (Miciomys) wrangeli. Wrangel, Alaska. 

(No. 74720, U. S. Nat. Mus.) 

13. Synaptomys (Synaptomys) hclaleies. Dismal Swamp, Virginia. 

(No. 75172, U. S. Nat. Mus.) 

14. Dicrostonyx torquatus. Petschora, Russia. 

(No. 3621, collection of Gerrit S. Miller, jr.) 

North American Fauna, No. 12. 

Plate I. 

^ 5 

5 5 

C " ij 


Q fc^is^-l 

16933—^0. 12 6 


[Enlarged two aud oue-half times.] 

Fig. 1. Bony palate of Phenacoinys. Salmon River Mouuiains, Idaho. 
(No. 31249, U. S. Nat.Mus.) 

2. Bony palate of Microius {Lmjurus) pallidiin. Reese River, Nevada. 

(No. 32498, U. S. Nat. Mus.) 

3. Bony palate of ^('cro/MS (/'(7//7H^8) j>j«e<or((r«. Washington, D. C. 

(No. 30.332, U. »S. Nat. Mus.) 
t. l>ony palate of Microius (Alticula) hlanfurdi. Nultar Valley, Kashmir. 
(British Museum Register, 81. 3. 1. 23.) 

5. Bony palate of MicnAiis (Microtus) arvalis. Geneva, Switzerland. 

(British Museum Register, 79. 9. 25. 52.) 

6. Bony palate of Microtus {Lag urns) lagurus. Gurjeff, Russia. 

(No. 3619, collection of Gerrit S. Miller, jr.) 

7. Bony palate of Microtus (Arvicola) arvicoloides. Type. Lake Kichelos, 

(No. 1358, collection of S. N. Rhoads. ) 

8. \ionj -pal&te of Microtus {Anteliomys) chlnensis. Type. Western Sze-chuen, 


(British Museum Register.) 

9. Bony palate of Microtus {Xeojiher) alleiii. Florida. 

(No. 23452, U. S. Nat. Mus.) 

10. Bonj iihIaIg of Erotomi/s glarcoJ us. Ghristiania, Norway. 

(British Museum Register, 84. 10. 31. 11.) 

10. View perpendicular to plain of palate. 

10ft. View from below and behind at strong angle with jilain of 

11. Bony jialate of Microtus {Eothenomijs) met anog aster. Western Fokien, China. 

(British Museum Register, 92. 10. 12. 52.) 

12. Bony palate of Dicrostonyx torquatus. Petschora, Russia. 

(No. 3621, collection of Gerrit S. Miller, jr.) 

13. Bony palate of Fiber. Lake George, New York. 

(No. 67689, U. S. Nat. Mus.) 

14. Bony palate of Lemmus lemnius. Vola. (From St. Petersburg Museum. ^ 

(No. 3620, collection of Gerrit S. Miller, jr.) 

14. View perpendicular to i)laiu of palate. 

14a. View from below and behind at strong angle with plain of 

North American Fauna, No 12. 

Plate II, 

^ p 

P 2 
•S ? 

Oh -J 


[Enlarged two and two-thirds times.] 

Fig. 1. Synaptomys cooperi. Roan Mountain, North Carolina. 
(No. 50865, U. S. Nat. Mas.) 

1. Left mandible from beneath ; bone cut away to expose roots of 

la. Left mandible from inner side; bone cut away to expose roots of 

2. Pheiiacomys oramontis Rhoads. Mount Baker, British Columbia. 

(No. 3562, collection of Gerrit S. Miller, jr.) 

2. Left mandible from beneath ; bone cut away to expose roots of 

2a. Left mandible from inner side; bone cut away to expose roots of 

3. Microiii8 pennsylvanicus. West Tisbury, Mass. 

(No. 1885, collection of Gerrit S. Miller, jr.) 

3. Left mandible from beneath; bone cut away to expose roots of 

3a. Left mandible from inner side; bone cut away to exi)ose roots of 

4. Evotomys yapperi. Seekonk, Mass. 

(No. 193, collection of Gerrit S. Miller, jr.) 

Left mandible showing effect of excessive wear on teeth. 

North American Fauna, No. 12. 

Plate III. 


1. Synajjtomys. 

2. Phenacamys. 

3. Micrdtiis. 

4. Evotomys. 



IN"©. 13 

[Actual tlate of jjublicatioii, October 16, 1897.] 






Prepared under the direction of 




189 7 


U. IS. Department of Agriculture, 

Division of Biological Survey, 

Washinf/ton, D. C, July 1, 1897. 
Sir: I have the honor to transmit herewith, and recommend for pub- 
lication, the manuscript of No. 13 of North American Fauna, comprising 
a monographic revision of the bats of the family Vespertilionidfv inhab- 
itiug North America north of Panama, by Gerrit S. Miller, jr. It is 
based mainly on material belonging to the Biological Survey, Avhere 
tlie work has been done. 

The Department is constantly in receipt of bats sent for identifica- 
iou and of letters of inquiry concerning these animals; but heretofore, 
owiDg to the chaotic state of the literature relating to this group and 
the uncertainty respecting the status of the various species, it has been 
impossible to answer such inquiries with any degree of certainty. The 
present paper is intended to remove these difficulties. 
Eespect fully, 

C. Hart Merriam, 

Chief, Biological Survey. 
Hon, James Wilson, 

Secretary of Agriculture. 



Material 7 

Changes iu color of s])ecimens preserved in alcohol 8 

8exnal variation 8 

Agt? variation 8 

fieograpliic variation 9 

(Geographic distribution 10 

Migration 10 

Measurements 11 

Illustrations 12 

Nonieuclature of North American Vespertiliouidie 12 

1. Generic and subgeneric names 12 

2. Specific and subspecilic names 20 

Lists of North American Vespertilionidic 38 

Descriptions 41 



1. Ears of Myotis velifer, il. californicus, M. ynmanensis, M. Ilijisanodes, M. evotis, 

Xycticeius humeralis, Ehogeessa gracilis, B, tumida, Corynorhinus viacrotis town- 
seiidii, Euderma maculatum, Jntrozous pallidiis. 
Uropatagia of Ehogeessa fjvacilis, I\. tumida, Xycticeius hnvieralis. 

2. Uropatagia of Ahjotis californicus. M. yumanensis, 21. evotis, M. thysauodes, M. relifer. 

3. Wiugs of Plecotus, Corynorhinus, Euderma, aud Lasiurus. 


1. "Wings of Vespertilio serotinus. 

2. Anterior part of rostrum of species of Phyllostomatidw aud Vespertilionida;. 

3. ^IvLzzie of Antrozous. 

4. Abnormal front teeth of Antrozous. 

5. ^\i\\\\B of Antrozous. 

6. Teeth of Antrozous. 

7. Muzzles of riecot us and Corynorhinus. 

8. Skulls of two subspecies of Corynorhinus. 

9. Teeth of two subspecies of Corynorhinus. 

10. Upper incisors of three specimens of Corynorhinus. 

11. Skulls of My Otis myotis, M. thysanodes, aud M. nigricans (top). 

12. Skulls of Myotis myotis, M. thysanodes, and M. nigricans (side)., 

13. Ear of Myotis snhulatus, M. Jccenii, M. lucifugus, and M. alascensis. 

14. Teeth of Myotis yumanensis, M. lucifugus, M. lucifugus longicrus, M. relifer, 

15. Teeth of Myotis californicus, M. subulatus, M. evotis, M. thysanodes. 

16. Maxillary teetli of four specimens of Myotis thysanodes. 

17. Abnormal premolar of Myotis thysanodes. 

18. iiknW of Lasionycteris noctivagans. 

19. Teeth of Lasionycteris noctiragans. 

20. Ear of Pipistrellus suhfavus aud P. hesperus. 

21. Skull of Pipistrellus hesperus and P. subflacus (top). 

22. Skull of Pi2ns1r ell us hesperus and P. siihflarus (side). 

23. Tee1h of Pipistrellus hes2)erus and P. suhfiarus. 

24. Skull of Vespertilio hahamensis, V. fuscus, aud V. serotinus (top). 

25. Skull of Vespertilio hahamensis, V. fuscus, and V. serotinus (side). 

26. Teeth of Vespertilio serotinus, aud four subspecies of V. fuscus. 

27. Ear of Lasiurus horealis aud L. teliotis. 

28. Skull of Lasiurus horealis and L. teliotis (top). 

29. Skull of Lasiurus teliotis and L. horealis (side). 

30. Teeth of Lasiurus teliotis and L. borealls. 

31. Skull of L^aslurus cinereus. 

32. Teeth of Lasiurus cinereus. 

33. Skull of Dasypterus intermedins. 

34. Teeth of Dasypterus intermedlus. 

35. Skull of Xycticeius humeralis. 

36. Teeth of Xycticeius humeralis. 

37. Incisors of Ehogeessa aud Xycticeius (front"). 

38. Incisors of Ehogeessa aud Xycticeius (crowns). 

39. Skull of ii'/(o_^e('8s« tumida. 

40. Teeth of Ehogeessa tumida and E. gracilis. 


No. 13. NOETH AMERICAN FAUNA. October, 1897. 



By Gerrit S. Miller, Jr. 

Writers on American bats have published a large mass of facts con- 
ceruiug the distribution and comparative anatomy of members of the 
family Vesperfilionida'. Unfortunately, however, no work has yet 
appeared in which the numerous species by which this group is now 
known to be represented in North America^ are treated from the stand- 
point of the systematic zoologist. In other words it has hitherto been 
impossible for anyone not thoroughly acquainted with the extensive 
and scattered literature of North American bats to identify specimens 
correctly. The present paper has been prepared with special reference 
to the loug-felt want of a ready means to accomplish this object. 


The greater part of the material on which this revision is based is 
contained in the collection of the Biological Survey of the IT. S. Depart- 
ment of Agriculture. This collection of bats, which consists of more 
than 0,000 specimens, chiefly in alcohol, has been brought together dur- 
ing the past few years by the held naturalists of the Survey. In addition, 
the writer has examined the bats in the United States National Museum, 
the American Museum of Natural History, and several private collec- 
tions, making a total of about 2,700 specimens of North American 
Vesp(rtilio)tlda'. It is to be regretted that so few South American bats 
are contained in the museums of the United States that no definite con- 
clusions can be reached concerning the relationships of several Mexican 
Species to the forms occurring farther south. For this reason certain 
questions of nomenclature must for the present remain in a condition 
of uncertainty. It is also to be regretted that comparatively fi^w well- 
prepared skins are available for comparison. Without good series of 
dry specimens it is impossible to determine the limits of individual 
variation in color, as conclusions of the most general kind only can be 
based on specimens that have been subjected to the action of alcohol. 
Series of bat skins as extensive as those by which most groups of small 
North American mammals are now represented will doubtless i)rove 

'In the present paper the term North America is used to indicate the whole of the 
North American continent and the West Indies. 


the existence of several well-marked geograpliic races in addition to 
those now recognizable. 

In tlie lists of specimens examined it lias not been thought necessary 
to distinguish between those contained in the IS^ational Museum proper 
and those in the collection of the Biological Survey. Specimens from 
other collections, however, are always specially designated. 


Bats which have been kept in alcohol for a i)eriod of more than a 
few mouths become so altered in color that they furnish reliable char- 
acters of size and form only. The rate and amount of change appear 
to vary with different species as well as with the strength of the jire- 
servative fluid and the amount of exposure to light. 1 have seen two 
lots of specimens of one species collected at the same place and on 
practically the same date and su[)posedly treated in the same way, yet 
after six years' immersion in alcohol those in one bottle still retained 
essentially their normal color, as proved by comparison with skins col- 
lected at the sanie time, while those in another bottle were so bleached 
as to show scarcely a semblance of their original appearance. 

While the details of the changes produced by alcohol are not known, 
it may be said that a gradual bleaching and ultimate entire loss of 
color is the general rule, though as a preliminary step browns are often 
very noticeably reddened. The subject is one that merits exj^erimental 


The range of sexual variation in North American Vesjiertilionida' is 
always slight and in many cases scarcely api)reciable. For tlie most 
part it consists in the slightly greater a\'erage size of the females. 
Even this is often trifling or absent, as in the case ot Myotis hicifiifjus 
longicnts from Nicasio, Cal., six males of which average: Total length, 
Ito.l; tail vertebrie, 45.8 ; forearm, 37.8; ear, 11.8; tragus, 7.3; while six 
females from the same locality average: Total length, 9G.3; tail ver- 
tebra:', 44.1 ; forearm, 37.3; ear, 12.1; tragus, 7.2. In general, however, 
it is necessary to take this factor into consideration when comparing 
specimens from widely se])arated localities, I know of no instances 
of constant sexual differences in color among North American Vesper- 
tiIionid(v, and only one of differences in cutaneous structures, that of 
L'hofjeissa gracilis^ in which the only known male has in each ear a 
distinct glandular swelling, absent in the two females that I have 
examined (see PI. I, fig. 7). 


Young bats when nearly full grown often present characters different 
enough from those of the adults to cause confusion in identification. 
The fur of such immature specimens is usually shorter and more woolly 


than that of the adults and the color darker and duller. The immature 
skull ditters in size and form from that of the adult, but as the sutures 
disappear at an early age, it is often somewhat ditticult to recognize. 

I have found that the best guide to the age of those bats that I have 
studied is the condition of the linger joints. In specimens young 
enough to furnish unreliable characters these are always large and 
looselj' formed, with epiphyses sei^arate from the ends of the j)halanges 
and metacarpals, both of which are distinctly enlarged for some dis- 
tance from the joint (tig. I a). In adults the tinger joints are small and 
compact, the epiphy- 
ses no longer visible, 
and the ])halanges of 
essentially the same 
diameter throughout 
(tig. 1 h). These dif- 
ferences are equally 
a))parent in alcoholic 
specimens and in 
dried skins. 


As comi)ared with 
other small mammals, 
bats show remarka- 
bly little geogra])hic 
variation in size, pro- 
portion s, or color. 
Thus bleeding indi- 
viduals of Xycticeius 
humeral is from Car- 
lisle, Pa., Dismal 
Swamp, Virginia, and 
the extreme southern 
point of Texas are 
alike in color,' while 
in size they agree almost as closely as any three lots of specimens 
from one locality.'- The onl}- difference that can be found is a slight 
northward increase in size of the ears. Specimens of Myotis Uici- 
fufiihs from Washington, D. C, are not distinguishable from a series 
taken on Kadiak Island, Alaska, and skins of Lasiurus clnereus from 
Minnesota are exactly like others from southern California. While 
such constancy of characters in wide ranging species is unparalleled 
among American mammals, the only ones of which it is yet possible to 

1 So far as cau be ascertained from comparison of specimens in alcohol. 
^See table of measurements on page 120. 

Fig. 1. — W)u<rs of Vespertilio serotinus: a, adult ; h. immature (natural 


speak with certaiuty, the explanation of the fact is probably very sim- 
ple. Living throughout the warmer part of the day in cool, dark, ami 
for the most part damp situations, bats, even in widely separated locali- 
ties, are exposed to comparatively little variation in temperature. 
Feeding at a distance above the surface of the ground and during the 
hours between sunset and sunrise, when colors are scarcely distin- 
guishable, they are jiractically freed from that necessity for protective 
coloratioii which binds the color of most mammals so closely to that of 
their surroundings. From this reduction in the force of two of the 
most powerful factors in the production of geographic variation — dif- 
ferences in temperature and need for protective coloration — the com- 
parative constancy in the characters of bats naturally results. 


From the peculiar habits of bats it results that the ranges of these 
animals are less closely limited by life areas than in the case of most 
mammals. To be more accurate, the frequent dampness and usual low, 
even temperature of the retreats occupied by bats during the hot 
part of the day expose the animals to essentially similar conditions 
wherever they may be, so that a given region of like environment is 
much more extended geographically for a bat than for most other 

Therefore, although many species seemingly disregard the laws of 
geographic distribution, their independence is more apparent than real. 


A factor which introduces much uncertainty into the study of the 
distribution of bats is the little understood migrations which some 
species are known to make. That many bats migrate is a well-estab- 
lished fact, but the extent to which migration aff'ects the apparent dis- 
tribution of species is not known. 

Although there are probably earlier references to the subject, the 
first mention of bat migration that I have seen is by Dobson, in bis 
Catalogue of the Chiroptera in the British Museum, published in 1878. 
In his remarks on the geographic distribution of Pipistrellus abramuSj 
Dobson says: "Found during the summer months in the Pahearctic 
region throughout middle Europe; * * * evidently migrates north- 
ward, * * * asithasnever been taken in Europe in winter" (p. 227). 
In 1888 Dr. C. Hart Merriam published evidence in the Transactions of 
Idae Eoyal Society of Canada (V, Section V, p. 85), which showed con- 
clusively that two American bats, Lasiom/ctcri.s noctivagans and Lasi- 
urus cinereus^ perform regular periodical migrations. Xo details of the 

'Analogous condiMons are found in sphagnum bogs and heavy, damp woodlands, 
in which animals of northern affinities, such as shrews, lemmings, and red-backed 
mice, extend far south of the normal limit of their kind. 


extent or exact dates of tbe northward aud southward movements 
could then be giveu further than that the known southern records of the 
hoary bat (Soutli Carolina, Georgia, Bermuda Islands) were all during 
autumn and winter, and that the silver-haired bat occurred in spring 
aud fall about the lighthouse on Mount Desert Eock, 30 miles oft' the 
coast of Maine, a treeless islet where bats were at other times unknown. 
In August and September, 1890 and 1891, I liad an opportunity to 
watch the appearance and disappearance of three species of bats, Lasi- 
onycteris noctivagans, Lasiurus hoi-ealis, and LaHiurus cinereus^at High- 
land Light, Cape Cod, Massachusetts. The animals, which were not to 
be found during tlie early summer, suddenly became numerous shortly 
after the middle of August aud remained abundant for about a month, 
when they as suddenly disappeared. The regularity with which this 
phenomenon occurred on the two successive years over which my obser- 
vations extended shows that the migration of bats is probably as defi- 
nite as to dates aud paths as that of birds. ^ 


For general purposes of identification, ten measurements are useful. 
Theseare : Total length, tail vertebni^, tibia, foot, forearm, thumb, longest 
finger, height of ear from meatus, width of ear, and height of tragus. 
The lengths of the separate phalanges of the fingers are important in 
special cases only. 

The tables which accompany the descriptions of the different forms 
contain average measurements of specimens selected from as wide a 
range of localities as possible. Whenever the full complement of meas- 
urements is given, it is to be understood that all have been taken from 
alcoholic specimens by the writer. When the total length, lengtli of 
tail, and the three measurements of the ear are omitted, the measure- 
ments have been taken from the dried skin. In a few cases the skin 
measurements are supplemented by the collector's measurement of total 
length and tail veitebra\ The use of specimens preserved in alcohol 
introduces a source of error in two measurements — total length and 
length of tail. According to the strength of the preservative fluid, both 
body and tail are to a varying degree shrunk or relaxed, so that consid- 
erable discrepancies in the averages of specimens taken at different 
localities by different collectors may result. In general, it is probable 
that these two measurements as given in the tables are a trifle shorter 
than they would have been if taken from fresh material. 

It is unfortunate that detailed measurements of individuals can not 
be published, since averages are of use for comparison with averages 
only, and it often happens that a single specimen must be identified. 
Averages, moreover, give no indication of the normal range of indi- 
vidual variation at a particular locality. 

'A detailed accouut of the migration of bats on Cape Cod was iiublislied in Science, 
N, S., V, No. 118, pp. 541-543, April 2, 1897. 



Tlie illustrations in this paper are reproductions of pen-and-ink 
drawings made under iny constant supervision bj'' Mr. Frank Miiller. 
Special difficulty lias been encountered in obtaining satisfactory repre- 
sentations of the external ear and of the crowns of the teeth. 

The ears of alcoholic specimens are generally sufficiently altered in 
form, by pressure and by the action of the preservative tluid, to 
retain only approximately the appearance which they had in the living 
animal. This is especially the case with such large-eared species as 
AnirozouH imlUdns, Corynorhinus viacrotis, Myotis erotis, and others. 
In the impossibility of reproducing their original appearance, it has 
been thought best to represent the ears in a uniform but somewhat 
unnatural i)osition, with the conch flattened and the external basal 
lobe tui-ued outward. This will account for the apparently undue 
width of certain drawings. 

The crown views of the teeth were first sketched with the aid of a 
camera lucida and afterwards corrected and finished by the use of hand 
lenses. The great difficulty in obtaining accurate and uniform results 
arose from the impossibility of kee])ing specimens in exactly com- 
parable positions and from the considerable changes in outline result- 
ing from every slight variation in the angle of vision. Therefore the 
drawings are not wholly satisfactory. They are published, however, 
in the belief that, such as they are, they nmy help to an understanding 
of the characters of the species. 


To arrive at final conclusions in regard to the nomenclature of the 
VesjiertUionuJw of North America, it will be necessary to consider in 
detail all names that have been based on those members of the groui) 
that inhabit the region in question, and also a few based on allied Old 
World species. The names may best be taken up alphabetically. 

1. Generic aud Subgeneric Names. 

Adelonycteris H. Allen, 1892 ( Proc. Acad. Js^at. Sci., Phila., 1891, p. 4G6, 
Jan. 19, 1892), was proposed as a substitute for Vesjferus Keys. & Bias., 
preoccupied in Entomology by Vesperus Latreille, 1829. The name is, 
however, a synonym of YespertiUo Linmeus, 1758, Eptesicus Eatinesque, 
1829, and also of Cneph(vus Kaup, 1829. 

Aeorestes Fitzinger, 1870 (Sitzungsber. Math.-Xat. CI. K. Akad.Wiss., 
Wien, LXII, Abth., I, i)p. 427-430), is a synonym of Myotis Kaup, 1829. 
The group included three South American species, Myotis viUosissimus, 
M. nif/ricans, and M. albescens. 

Antrozous H.Allen, 1862 (Proc. Acad. Xat. Sci. Phila., p. 248), is the 
only generic name based on Vespertilio paUidus Le Conte. 


Atalapha Eafinesque, 1814 (Precis des Decouv. et Travaux Somio- 
lofticiues, p. 12), is clearly based ou a Sicilian bat.' The use of the 
name for a geuus coufiiied to America is therefore impossible. 

Brachyotus Kolenati, 1856 (Allgem. Deutsch. Naturhist. Zeitg., Dres- 
den, Xene Folge, II, pp. l.'U, 174-177), is a subgeiieric name based on 
three European species of ' Vespertilio'' {my.stacinus, dauhentonii, and 
dasycneme) with ears shorter than head. 

Cateorus Kolenati, 1856 (Allgem. Dentsch. jSTaturhist. Zeitg., Dresden, 
Xeue Folge, II, pp. 131, 102-103), a subgeneric name based ou '■Yefiperus' 
serotinus, is a synonym of Vespertilio Linufeus. 

Cnephaeus Kaup, 1829 (Skizzirte Entw.-Gesch. u. Natiirl. Syst. d. 
Europ. Thierw.. Ister Theil, p. 103), is a generic name based on Yesper- 
tilio serotinus Schreber, a species congeneric with Ves2)ertilio fuscus of 
America. The name is a synonym of Vespertilio. 

Cnephaiophilus Fitzinger, 1870 (Sitzungsber. K. Akad. Wiss., Wien, 
LXII, Abth. I, p. 81), is a genus composed of very heterogeneous ele- 
ments among which no type is mentioned. The species referred to it 
are macellus ('Borneo'), peUucidus ('S. E. Asia, Philippines'), ferriigi- 
?^e^^s•('Mittel Amerika, Surinam'), and the North American noctivaf/ans. 
Whether or not the name may be available for some of the other spe- 
cies, it certainly is not for the one which comes within the limits of the 
present paper, since this was already provided with the generic name 

Comastes Fitzinger, 1870 (Sitzungsber. Math.-Xat. CI. K. Akad. 
Wiss., Wien, LXII, Abth. I, p. 5Go), is a synonym of Myotis Kaup, 
unless it may eventually be shown that the sijecies on which it was 
based, capaccinii, megapodius, dasycneme and limnopMlus, are subgeu- 
erically distinct from Myotis myotis. 

Corynorhinus II. Allen, 1865 (Proc. Acad. Xat. Sci. Phila., p. 173), 
proposed as a generic name for Flecotus maerotis Le Coute and F. 
toirnsendi Cooper, is the only available name for the group of which 
CorynorJiinus maerotis is the only known species. 

Dasypterus Peters, 1871 (Monatsber. K. Akad. Wiss., Berlin, 1870, p. 
912, published 187J ), was established as a subgenus of Atalapha { = Lasi- 
tirns) to contain the species intermedia, eyregia, ega, and caudata. It 
has recently been raised to full generic rank by Dr. Harrison Allen. 

Eptesicus Eafinesque, 1820 (Annals of Nature, p. 2), originally cou- 

'II. G. ATALAPHA (Chanve-sonris). Incisivesnullesaux deux nii'ichoires, canines 
et uiachelieres aigues: aucuue crete sur le nez. queue lU'esqu'entierement unie aux 

2. Atalaplia sicitla. — Oreilles de la longueur de la tete, et auriculoes, une verrne 
sous la ir-vre inferieure; corps roux brnnutre en dessus, roux cendro en dessous, ailes 
et museau noiratre, queue saillaute par une pointe obtuse. — Obs. J'ai observo cette 
espece en Sicile, elle ditt'cre de V Atalapha ameruona (Vexprrtilio tiorehoracenxis Lin.), 
autre espece du menie genre, par ees deux premiers et son dernier caractere. 


taiued two species, E. melanopn aud E. mydas.^ Eptesimis melanops is 
without doubt the Yespertilio fuscus of Beauvois. E. mydas, however, 
cau not be identified (seep. 32). The first species must therefore be 
taken as the tyi)e. Since this species is congeneric with Vespertilio 
murinus Linna'us {=Vesperiigo discolor batterer), the type of the genus 
Vespertilio, the name Eptesicns is a synonym of Vespertilio. 

Euderma IT. Allen, 1892 (Proc. Acad. Nat. Sci. Phila., 1891, p. 467, 
published Jan. 10, 1892), is the tenable name for the genus of which 
Eistiotns maculatus J. A. Allen is the type and only known species. 

Histiotus Gervais, 1855 (Exped. Comte de Castelnau Am.du Sud, Zool., 
Mamniif., p. 77, PI. XII), was based on the South American Plecotus 
velatus of Geofifroy. Euderma maculatnm was originally described as a 
member of this genus, the name of which has not otherwise appeared 
in the literature of North American Vespertilionida\ 

Hypexodon Eatiuesque, 1819 (Journal de Physique, de Chlmie, d'His- 
toire naturelle et des Arts, LXXXVIII, p. 417), can not be identified 
with any known group of bats. The characters which Rafinesque 
assigns to the type species^ may be those of a mutilated aud distorted 
specimen of someof the small species of Xycticeius, Pipistrellvs, ovMyotis. 

Hypsugo Kolenati, 1856 (Allgem. Deutsch. Xaturhist. Zeitg., Dres- 
den, Xeue Folge, II, pp. 131, 167-l(i9), is a synonym of Pipistrellus 
Kaup. It was based on ' Vesperugo'' maurvs Blasius aud ' V. ' Tcrascheni- 
nil'oivii Eversmann. 

Isotus Kolenati, 1856 (Allgem. Deutsch. Naturhist. Zeitg., Dresden, 
Xeue Folge, II, pp. 131, 177-179), is a subgeneric name based on two 
European species of ' Vespertilio ' {nattercri and eiliatus) which have the 
ear about equal in length to the head. It is of course a synonym of 
Myotis Kauj), 1829, and of Selysius Bonaparte, 1841. 

Lasionycteris Peters, 1865 (Monatsber. K. Preuss. Akad.Wiss., Berlin, 
1865, p. 648), is the first name proposed for the genus of which Vesper- 
tilio noctivagnns Le Conte is the only known species. 

Lasiurus Gray, 1831 (Zoological Miscellany, Xo. 1, p. 38), is the first 

'The original diagnosis of the genus Eptesicns is as follows: 

" I. N. G. EPTESICUS. Four acute foie-teeth to the upper jaw, in two equal ])air8, 
separated by a great interval and a large flat wart, each pair has two unequal 
teeth, the outside tooth is much larger and unequally bifid, the outside one much 
larger, inside tooth small and entire. Six fore-teeth to the lower jaw, equal very 
small, close and truncate. Canine teeth very sharp, curved and long. Grinders 
unequally trifid. Snout plain, nose without appendages. Ears sei>arated, auricu- 
lated. Tail mncronate. — This genus apjiears to differ from all those of Geoffroy and 
Cuvier, among the extensive tribe of Bats. The name means house-flyer." 

-1. Nouveau genre. HYPEXODON. (Chauvc-sourits.) Museau nu ; narines rondes, 
saillantes; incisives snporienres nulles, 6 inferieures omarginoes, uue verrue ala base 
extdrieure des canines inferieures. Queue eugagee dans la membrane. Le reste 
comme le genre VesperlU'io. — I espece H. iiu/stax, entiJ'rement fauve, dessus de la tcte 
brun, ailes et membranes nolres, queue mucrouee, des moustaches, oreilles brunes 
auriculecs, nervures inferieures et transversales; longueur totale, 3 pouces, dont la 
queue 2 pouces. En Kentucky. 


name based on the bats of the American genus commonly but wrongly 
called Atalapha. It was introduced as follows : " The bats, the Vesper- 
tilionc.s of Geoffroy, might for convenience be divided into three genera, 
the true bats, VesperUUo * * *, the Facliyotus * * *, and the 
hairy tailed species of America (Za-s'/ ;n- its)." As the only hairy-tailed 
American bats known in 1838 were members of the modern genus 
Lasiurus, this brief statement may be taken as a definite indication of 
the author's meaning. In 1838 Gray referred the species pruinosus 
{=cinen'U.s), lashiriis (= borealis), and hlos-sevillei (= horealis,Jif1e'Dobsou) 
to the group, which he then regarded as a subgenus or section of 
ScotophiluH (Mag. Zool. & Bot., II, p. 4!)8, Edinburgh, 1838). 

Marsipolaemus Peters, 1872 (Monatsber. k. Preuss. Akad. Wiss., Berlin, 
p. 200), was proposed in a subgeneric sense for a Mexican bat, Vesperns 
aJhigularis Peters, about the size of Ve,s2)ertilio fuscus, with the denti- 
tion of that species, but with the outer border of the ear continuous 
with a fold of skin which extends back from the corner of the mouth, 
under and behind which a distinct pocket is formed. I have never 
seen this bat, and am unable to say what value is to be placed on the 
characters described. (See \^. 101.) 

Meteorus Kolenati, 1856 (Allgeni. Deutsch. Katurhist. Zeitg., Dresden, 
Neue Folge, II, pp. 131, 107-101>), is a synonym of Yespertilio Linn;eus. 
It was proposed as a subgenus of '•Yesperus'' to include the species 
nilssimi, (lificojor, .s((vii, Ieucip2)e, and arisiippe. 

Myotis Kanp, 1829 (Skizzirte Entw. Gesch. u. Natiirl. Syst. der Euroj). 
Thierw., Ister Theil, p. 106), is the first name based on the large, long- 
eared, thirty- eight toothed bat wrongly called YespertUio miirinus by 
Schreber.^ It is therefore the tenable name for the genus of which this 
animal is the type. As the Yespertilio murinus of Schreber is not the 
Yespertilio murinns of Linna'us, another specific name must be applied 
to the former. The name w^/oif/s Bechstein- is available for this i>ur- 
pose. Hence the Yespertilio murinus of Schreber and of European 
writers in general nmst stand as Myotis myotis (Bechstein). 

Nannugo Kolenati, 1856 ( Allgem, Deutsch. Naturhist. Zeitg., Dresden, 
Neue Folge, II, pp. 131, 169-172), is a synonym of Pijnstrell us Kanp, 
1829. It was proposed as a subgenus of ^Yesperugo'' to include the 
European species jnpistrellus, IcuhlH, and nattereri. 

Noctula Bonaparte, 1837 (Iconografia Fauna Italica, I, fasc. XXI, 
under Yespertilio alcythoe), based on Yespertilio serotinus Schreber is a 
synonym of Yespertilio Linnteus. 

Nycticeius Rafinesque, 1819 (Journal de Physique, de Chimie, d^His- 
toire Xaturelle et des Arts, LXXXVIII, p. 417), contained two species, 

'Kaup says: " Fledermihise von riesenmiissiger Grosse, mit nacktem Gesiclit, 
getreuiiteu, kopfslangeii Ohreii, langeu lanzettformigen Ohrendeckelu, iind 38 

-resperiilio mi/otis Beclisteiu, Gemeiniiiitz. Naturgesch. Deutschlauds, Bd. I, p. 
1145, 1791 (fide Blasius). 


N. humeralis Eaf. aud N. tesselatus Bat JSTotliiug in the description' 
indicates which of these the author considered as the type. Nycticeiiis 
tesselatus Raf. is Lasiurns horealis (Miiller), and ^. humeralis may with 
some degree of probability be identified with the small brown bat more 
generally known as Nycticejus crepuscularis Le Conte,- There is cer 
tainly nothing in the diagnosis of the genus or in the description of 
yespertlUo humeralis previously published in the American Monthly 
Magazine that precludes this possibility, while the size, the number of 
incisors, and the naked uropatagium point directly toward it. As 
horealis was removed to tlie genus Lasiurus by Gray in 1838, humeralis 
becomes the type of Nycticeius. The orthography of this name has had 
several emendations, as Xycticcus, Kycticejus, Xyeticea, and Nycticeyx. 

Nyctilestes Marsh, 1872 (Amer. Journ. Sci. & Arts, 3d ser., IV, p. 
215), is a fossil genus based on part of a lower jaw and molars from 
Eocene or Lower Miocene strata near Henrys Fork, Wyoming. The 
remains present no characters to distinguish them generically from 
Vespertilio. Only one species, Nyctilestes serotinus, has been described. 

Nyctitherinm Marsh, 1872 (Amer. Journ. Sci. & Arts, 3d ser., IV. p. 
127), is a genus based on the fragments of two lower jaws found with 
teeth in place, from Tertiary strata at Grizzly Bnttes, Wyoming. The 
original description indicates no characters by which these teeth may be 
distinguished from those of small species of Fipistrellus or Vespertilio. 

Nystactes Kaup, 1829 (Skizzirte Entw.-Gesch. u. Natiirl. Syst. der 
Europ. Thierw., Ister Theil, p. 108), based on Vespertilio bechsteinii 
Leisler is strictly synonymous with the same author's Myotis? 

Pachyotus Gray, 1831 (Zool. Misc., ISo. 1, p. 38), was first used as the 
name for a genus made by the combination of Xycticeius aud !Scotophi- 
lus. Later (Mag. Zool. & Bot., II, p. 498, 1838) Gray transferred it to 
Vespertilio villosissimus Geoffroy in a subgeueric sense. The name is 
of course untenable.* 

Fipistrellus Kaup, 1829 (Skizzirte Entw.-Gesch. n, Xatiirl. Syst. der 
Europ. Thierw., Ister Theil, p. 98). This name was based on Vespertilio 
pipistrellus Schreber, a species strictly congeneric with the ' Vesper ugo 

12. NYCTICEIUS. (Chaiive-souris.) Diftere du genre pr^cMent iHypexodon'] par 
2 iucisives superieures separees par un graucl iutervalle, accoldes aiix cauiues et h 
creuelures aigui-s, 6 incisives iuf6rieures trouqu(?es. point de verrues aux cauiues.— 
Ce genre coutient an moius 2 espi'ces, X. humeralis et N. tesselatus, que j'ai dojii 
d^crits dans VAmeriva)) Monthly Mafjaziue, sous la denomination geuerique Vespertilio, 
avec plusieurs autres uouvelles espt'ces de ces contrces. 

•See Tliouias, Anu. & Mag. Nat. Hist., 1891, 528. 

• Kaup says : " Fledermiiuse luit sehr laugen getrennteu Ohren, langem zugespitzem 
Ohreudeckel, 38 Ziihncn uud spitzmausiilinlicliem Kiissel." 

■■The original reference is as follows: ''The bats, the VespertiJiones of Geott'roy, 
might for convenience be divided into three genera, the true bats, Vespertilio, with 
thin ears and membranes aud a hairy face, the Pachyotus, with thick ears and mem- 
branes and bald swollen cheeks, including the genera Nycticejus and Scotophilus, aud 
the hairy-tailed species of America {Lasiurus)." 


georgianus'' of tlie United States, It autedates the name Vesx)erugo by 
exactlj' ten years, 

Plecotus Geoflfroy, 1818 ' (Description de I'lOgypte, Mamniiferes, p. 112), 
included tbree species, TOreillaid de Daubeuton,' 'la barbastelle,'and 
a new species from Timor.^ 

As no American bats are congeneric with the species originally 
included in this genus, the name can not be used for any of the genera 
now under consideration. It has been applied to the species of Cory- 

Rhogeessa H. Allen, 1866 (Proc. Acad. Nat. Sci. Phila., p. 285), was 
proposed as a genus to contain the species B. parvnla II. Allen and R. 
tumida H. Allen. The group, whose validity has not been questioned, 
has received varying treatment at the hands of difl'ereiit writers. 
Dobson placed it as a subgenus under ' Vesper ugo,^ but Thomas has 
recently pointed out its close relationship to Xyeticeius. The latter 
disposition appears to be the more natural. 

The name has been amended to Bhogoessa by Marschall (Nomenclator 
Zoologicus, Mamm., p. 11, 1873). 

Scotophilns Leach, 1821 (Trans. Linn. Soc. London, XIII, pt. l,p. 00), 
type iS. Jxuhlii Leach, is a genus peculiar to the Old World, where it 
apparently replaces the Lasiiirus of America. Jt is mentioned here 
merely because the mime has been used for the North American species 
of Laslurus, Vespertilio, Lasionyeteris, and npisfrellns at times when 
these bats were supposed to be congeneric with Old World species. 

Selysius P.onaparte, 1841 (Iconografia Fauna Italica, I, Introduzione 
[p. .'>] ), is a synonym of Myotis Kaup, 1829. It was based on the 
common European YesperUlio mystacmus of Leisler. 

Synotus Keyserling and Blasius, 1839 (Wiegmann's Archiv f. Natur. 
geschichte, r)ter Jahrgang, Bd. I, pp. .'>0.">, 30(>), was based on the bar- 
bastelle, a European bat representing a genus not known to occur in 
America. The mime, however, has been applied to the American genus 
afterwards called Gorynofhiniis. It is antedated by Barbastel la Grtky, 
1821 (London Medical Kepository, XV, \}. 309. Type Vesper tilio barbas- 
tellus Schreber). 

Taphozous (leoli'roy, 1818' (Description de l'l5gypte, Mammiferes, p. 
113), based on ' Le lerot-volant' and 'le V. lepturus,^ which are without 
representatives in America. The red bat {LasiKvui'i borenUs) was, how- 
ever, included in this genus by ( Jodnuin under the name Taphozous ru/us.-^ 

' See Sherborn, Proc. Zool. Soc. Londou, 1897, p. 288. 

4 2 5-5 

-Dents incisives g; canines ., ; niolaires ,,_,.. 'Nez simple et saillauf ; clianfrein 

large el mciplat. Oreilles plus (jrandcs que la tote, et rdunies; oieilloii iut<_^rieur. 
Membrane inteifcmorale ctendue et a angle saillaut. Queue longue et toute entiero 

Obs. Les trois espices do ce genre sont, Foreillard do Danbenton, la barbastello 
et uue noiivelle osptcc de Timor. 
^Fauua Americana, p. 23, 1825. 
2772 No. 13 2 


Fitzinger ' refers to a ' Taphozous hracJimanus Ciodmau ' amoug the syn- 
oiiyins of Last urns ^vk/ks^ (= horealis). This name, however, I have been 
unable to And in any of Godnian's writings. 

Vesperides Coues, 1875 (in Coues and Yarrow, Zool. of Wheeler's 
Exped., p. 83), was proposed as a subgenus of YesperUUo based on Yes- 
IwriUio noetivagans Le Conte. The name is antedated by Lasionycteris 
refers, 18G5. 

Vespertilio LinucTUS, 1758 (Syst. Nat., 10th ed., I, p. 31), eontaiued 
seven species: vampiirus, spectrum, persiyiciUatus, spasma, leporinus, 
auritus, and murinus. These have all been removed to other genera, as 
follows: vampyrus to Ptcropus in 1702 (Brissou, llegn. Anim., ed. II, 
pp. 13, 153), leporinus to NoctiUo in 1700 (Linna'us, Syst. Nat., 12th ed., 
p. 88), spasma to Mcgaderma in 1810 (Geoffroy, Ann. Mus. d'Hist. Nat., 
XV, p. 197), anritus to Plecotus in 1818 (Geoffroy, Descript. de I'Egyjjte, 
Mammiferes, p. 112), murinus'^ to Eptesicns in 1820 (Eafines(iue, Annals 
of Nature, 1820, p. 2), perspicillatus to Artihens in 1821 (Leach, Trans. 
Linn. Soc. London, XIII, p. 75), and spectrum to Vumpyrus in 1821 
(Leach, Trans. Linn. Soc. London, XIII, p. 79). 

The only European species are anritus and murinus, one of which 
nuist therefore become the ty])e of the genus. The species anritus was 
removed to the genus Plecotus by Geottroy in 18! 8, leaving murinus as 
tyi)e of the genus YcspertiUo. The YespcrtHio mnriuns of Linnanis is, 
however, a totally different animal from the bat afterwards described 
under the same name by Schreber. To understand the case fully it is 
necessary to go back to the first and second editions of Linuicus's 
Fauna Suecica. In the first ho records only one bat, the 'Laderlapp,' 
'Fliidermus' or 'Nattblacka,' Yespertilio caudatus, naso oreque simplici 
(No. 18, p. 7, 174G). In the second edition he mentions two, Y. caudatus, 
naso oreque simplici, anriculis duplicatis, capite majoribus, and Y. cau- 
datus, naso oreque simplici, anriculis capite minoribus (No. 2, pp. 1, 2, 
1701). In the tenth edition of the Systema Naturae these had been 
given binomial names, Yespertilio auritns and T'.w?/ri/y?(,s, respectively. 
The account of the teeth of the latter in the second edition of Fauna 
Suecica is as follows : ^ 

Deutes priiiiores superiores 6, aciiti tlistantes. 
iiiferiores 4, acuti coiitigiii. 
Laniarii superiores 2, anteriore innjore. 

inferiores 3, antico iiiaximo. 
Molares utriuque 3, tricuspidati. 

' Sitziingsber. K. Akad. Wiss. Wien, LXII, Iste Abtli., p. 402, 1870. 

"Altliougli Rafiuesque did not actually place the species murinus iu the genus 
JEptesicus he based the latter ou a strictly cougouerio forui. 

»In tbcfirst edition the dental formula is the same, except that the lower iucisors 
are said to be five in number, an error corrected iu the second editiou. 


It therefore appears that the Vespertilio murimis of Linnaeus is a bat 
with ears shorter than the liead, and with the deutal formula: 
. 2-21 i_i i_i ;3_3 

*' 3^ '^'1-1 '^'"'2-2 ''"'313 = ^^- 

The only common Scandinavian bats which combine these characters 
are the two usually known as Vespernyo nilssoni and Vesperuyo discolor. 
To these strictly congeneric European species and their exotic repre- 
sentatives the generic name Vespei't'dio must be applied, regardless of 
its long misuse for a different genus. 

The current misidentification of Linuaeus's Vespertilio murinus has 
been recognized by at least three writers on European bats, Nilsson, 
Blasius, and Lilljeborg. Nilsson^ discusses the matter at considerable 
length and arrives at the conclusion that the name murinus nuist be 
substituted for discolor^ while the bat commonly known as murinus 
must take the si^ecific name myotis Bechstein. As this author unites 
the genera ' Vesperugo ' and ' Vespertilio^^ he has nothing to say in regard 
to tlie validity of the generic names used by Keyserling and Blasius. 

Blasius' regarded Nilssou's identitication of Vespertilio uinrinus a^s 
doubtful, though he admitted that the animal described by Linnaeus 
under that name could not have been the one generally called Vesper- 
tilio muriuKs by European authors at large, lie therefore reasoned 
that Linua?us's name might be disregarded as undeterminable and in 
no way invalidating Schrcber's later application. 

Lilljeborg alone questioned the tenability of the generic name Vesper- 
tilio for the thirty-eight toothed bats of Europe.^ He says: 

* * ■ As regards modifying the Linuii'iiu _i;cueric name Vespertilio, it may be 
viri!;ed that Liuna-us did not include in it any of the species referred to it by Keyser- 
liiij; and Blasius. Furtber, it would have been more correct to apply the name 
respcrtilio to the preceding genus [' f'cspcn<(jo'], since one of the si)ecies included in 
the genus )»y Liuun-us ( i'espertilio murinus) agrees, in all important characters at 
least, with the genus mentioned, as shown above. As, however, the niodihcatiou of 
the name introduced by Keyserling and Blasius has become time-sanctioned, it will 
be retained, although we consider the objections against it reasonable.' 

Vesperugo Keyserling and Blasius, 1839 ( Wiegmann's Archiv f. Natur- 
gesch., 5ter Jahrgaug, Bd, I, p. 312), was proposed as a genus to contain 
the following species up to that time commonly associated with Vesper- 

' In Linna'us's statement the figures 4 and 6 are evidently transposed. 

'Skandinavisk Fauna, I, Diiggdjuren, 2ded., 1847, pp. 17-20. 

'Naturgesch. d. Siiugetbiere Deutschlands, pp, 74, 84, 1857. 

SSveriges och Norges Ryggradsdjur, I, Diiggdjuren, p. 144, footnote, 1874. 

■'■'* * * I afsecnde pa tilliimpningen hlir af det Linneanska genus-namnet 
Vespertilio, kan deremot inviludas, att Liun6 icke uti detta genus upptagit en enda af 
de arter, som Keyserling & Blasius derunder beskrifvit, och att det hade varit 
riittare, att auviinda detta namn ffir furegaende sliigte [' fesper;;*;©'], emedau en 
af de af Linne uti si. Vespertilio npptagna arterna — Vespertilio murinits Lin. — 
atmin^,toue till hufvudsaklig del, euligt hvad ofvan blifvit antVirdt tillhur niimde 
sliigte. Da cmellertid den af Keyserling &- Blasius infiirda tilliimpningen af 
naoinet vuuuit hiifd, vilja vi bibehalla den, ehuruviause inviiudningen vara befogad. 


tilio: serotinus, dhc(>l(>t\ iiils.soni, sdnii, leHcippc, (iri.stippe, noctula, leishri^ 
lultliij alboUmhatus, nathmii, iiiid pipistrellus. The first six were [)lace(l 
iu tlie new subgenus Ves2)erus, the others in the subgenus Vesperiujo. 
Hence the ty[)e must be a member of the second group. This group, 
however, ccmtaiiis two modern genera, the first represented by the spe 
cies itoctuht and leisleri, the second by JctiJilii, '■ albolimbatus'' {^^Jcuhlii, 
fide Dobsou), '• natluisW [^=abramus, fide Dobson), and pipistreJliis. 
These had ah^eady been named Ptrrygi.stes and PipistrelluH, respectively, 
by Ivaup iu ISl*!). Hence Vespenujo is untenable in any connectiou. 

Vesperus Keyserling and Blasius, 1839 (Wiegraann's Archiv f. Natur- 
gesch., oter Jahrgang, Bd. I, p. 31.")), pr()[)Osed as a subgenus of M'c.s- 
pcn((jo^ to incUide the species svrotiiiK.s, discolor, nilssoni, savii, leueippc, 
and aristippe, is antedated by Cnephwus Kaup, 1829, Eplesieus Eafines- 
(pie, 1820, and Vcspertilio Linnu'us, 1 TaS. It is moreover preoccupied iu 
Entomology by Vesperus Latreille, 1829. 

2. Specific and Subspecific Names. 

Affinis (Vespertilio). H. Allen, Mouogr. Bats N. Am,, p. 53, 1864. 
The type of Dr. Harri.son Allen's Vespertilio affinis, now in the United 
States National JNIuseuin, proves to be a tyi)ical example of Myotis 
luci/iKjus. It is therefore in no way related to the VespertUio nitidm 
or V, (ilbrsceibs of Dr. Allen's second monograph. 

Albescens (Vespertilio). E. (rcoftVoy, Ann. Mus. d'llist. Nat., Paris, 
VIII, p. 204, 1806. This is a South American species of Vli//o<u, i)roba- 
bly closely related to M.velifer (J. A. Allen). The measurements given 
by Azara and <|uoted in the original descrii)tion are: Total length, 80 
mm.; tail, 33; extent of wings, 235; ear, 14. The name albescens has 
been used by Dr. Harrison Allen for Myotis yumanensis, M. evotis, M. 
cali/oruicus {^Vespertilio albescens vielanorh inns''), M. reli/er, M. titysa- 
nodes (under M..velifer),imd M. hicifnyus (' Vespertilio albescens affinis''), 
which he unites as subspecies. 

Albigularis (Vesperus). Peters, Monatsber. K. Preuss. Akad. Wiss., 
Berlin, p. 2(30, 1872, Vesperlilio aibigularis (Peters) is the ty[)e of the 
subgenus MarsipoUvmus. The characters given in the original descrii)- 
tion indicate a well marked species, with which, however, I am wholly 
unacqmxinted. The type was collected in ftlexico. 

Alleni (Rhogeessa). Thomas, Ann. & Mag. Nat, Hist., (Uh ser,, X, 
p. 477, 1892. This is the only name for this species. 

Americana (Atalapha). Kafinesque, Precis des Decouv. Somiologiques, 
p. 12, 1814, This is a synonym of Lasinrus borealis (Miiller), though 
proi)erly speakiug the name is a nomen nudum (see p. 10(5). 

Arquatus (Vespertilio). Say, Long's Expedition to the Kocky Moun- 
tains, I, p, 107, footnote, 1823. Tlie description clearly indicates Ves- 
pertilio fuscus Beauvois. 

Auduboni (Vespertilio). Harlan, Featherstonehaugh's Monthly Ameri- 
can Journal of Geology and Natural History, I, p. 220, PI. II, November, 
1831, Both description and plate indicate the silver-haired bat. 


Austroriparius (Vespertilio lucifugus). lihoads, Proc. Acad. Nat. Soi. 
Pbila., 1). 227, May, 1897. Vc.sjX'rtUio Jucifngus austroripariuH Rlioads 
is a synonym of Myolis lud/w/ns (Le Coiite). The type, a two-thirds 
grown young from Tarpon Si)ri'ngs, Florida, shows nuinerons characters 
by which it may be distinguished from northern adults, but the full 
grown topotypes are, as originally determined by Dr. Harrison Allen 
(see IMioads, I.e.), indistinguishable from northern si)ecimensof /*<c//«- 
(jKs that have been immersed in alcohol for a similar period. Even if it 
Avere assumed that the Tarpon Springs bat difilerod in some way not 
now discoverable from the ' IncifiKjus of North Carolina and northward,' 
there could be little doubt that the southern form was the one originally 
described by Le Conte. (See page G3). 

Belli! (ScotopMlus). (iray. List Si)ec. IVlamm. Brit. Mus., p. 30, 1843. 
Scotophilus hellii (Iray is anoinen nudum probably based on one of the 
West Indian forms of Vespertilio fiiscus. Gray's account is as follows: 
"Bell's Bat. Scotophilus Bellii. ^/Inspirits. West Indies. — Pre 
sented by Thomas Bell, Esq., F. R. S." 

Borealis (Vespertilio). Midler, Natursyst. Suppl., p. 21, 1776. Midler's 
Vespertilio borealis is the first name based on the red bat, Lasiurus 

Brevirostris (Vespertilio). IVIaximilian, Wiegmann's Archiv. f. Natur- 
geschichte, 1801, Bd. I, p. 19.5. VespertUio brevirostris of Maximilian is 
probably Myotis lucifu(/ns (Le (\)nte). The original measurements 
are: Total length, 3"; extent, 9" 4'"; ear from crown, 5J'"; tragus, Lj'". 

Calcaratus (Vespertilio). Rafinesque, American Monthly Magazine, 
III, ]). 445, 1818. No known bat agrees with the description of Rati- 
nesque's Vespertilio calearatus^ which is as follows: "Tail one-third, 
body dark brown above, dark fallow beneath, wings black, shafts rose- 
coloured, a spur at the inner side of the elbow, hind feet black. Length 
4 inches, breadth 12." 

Californicus (Vespertilio). And. & Bachm., Journ. Acad. Nat. Sci. 
Phila., VIII, Pt. II, p. 285, 1842. This is the earliest name based on 
the small western bat commonly known as Vespertilio nitidiis H. Allen. 
The original description is as follows : ' 

r. ralifoi-niciis (C' bat). — V. fnsco Iiitosceiis, vellere loiijioet iiiolli; trago 
lnii<j;itu(lino diniidiuni anris cxccdcntc. 

('aliforiiian hat. — Witb long silky bair.s; tragus more tban balf tbo Icugtb of the 
ear; cobjr light yellowish brown. 

Descripfiou. — Anterior upper fore teeth bilol)ate. Head small; nose sharp; ears 
of moderate .lize, erect, rather narrow, and pointed. Trat/iis Ihuar, atleuiiatcd. \\'ings 
of moderate length, which together with the ears are naked, [nterfemoral mcmhranc 
Willi a. few scattered liairs; feet small; nails slightly hooked. Tail projecting a little 
beyond the intei'fomoral membrane. 

Color. — The peliige, which is uniisualhj lonf/ for the size of thehody, and very soft and 
glossy, is, on the upper surface, dark pluml>eous from the base, and hroadly tipt with 

' I have italicized statements specially applicable to ' f. nitidus.' 


lif/hf }iellowisli hrown; on the under siirfiico the color is a little darker, owing to the 

outer extremities of the hairs being more narrowly edged with the prevailing color 

on the back, exhibiting the darker shades beneath. The enrs and tragus are Idack- 

ish — the nose, chin, wings, and interfemoral membrane dark brown. 

Hah. — We have obtained but a single specimen, which was captured at California. 

2-2 1-1 

DenCition. — Incisors^. Canines :. |. 

DimenHons. — Length of head and body, 1 inch 7 lines [40 mm.] ; length of tail, 1 
inch 5 lines [35.8] ; length of spread, 7 inches C> lines [190] ; height of ear ]>nHteriorly, 
3 lines [6.35] ; height of tragus, 2 lines [3.8]. 

The only other small bats known to occur in California are Pipistrellus 
hesperus, Myotis thysaiiodes, M. ynmanensis, M. evotiSj and M. lucifiu/ns 
lonyicrus. That YespertUio californicus can not be Pipistretliis hesperus 
is shown by the description of the tragus. From Myotis tliysanodes it is 
separated by its small size and nnfriiiged interfemoral membrane; from 
M. yumanensis by its small feet; from M. evofis by its short ears, and 
from M. lucifugus longicrus by its light color and small size. Myotis 
thysanodes and 71/, lt(cifiigns lonr/icrtis are moreover comparatively rare 
bats in California, while ' YespertUio nitidns'' is one of the most common 
and universally distributed species. 

Carolii (Vespertilio). Temminck, Monographies de Mammal., II, p. 
237 (13me Monogr.), 1835-41. The YespertUio enrol H of Temminck is 
without doubt Myotis lucifugus (Le Conte). That it is a Myotis is shown 
by the number of teeth, six molars in each jaw, while that it is not M. 
svhulatus, the only other s[)ecies known to occur in the vicinity of Phil- 
adelphia or New York, is shown by the short ear, 11.5 mm. in length.' 

Carolinensis (Vespertilio). Geoffroy, Ann. du Mus. d'llist. Nat., Paris, 
VIII, p. 193, 1806.- 

This species is YespertUio fuscus Beauvois. Dr. Harrison Allen in 

'The essential part of the original description is as follows: 

"Taille et formes de notro pipistrellc, mais les oreiiles plus longues. * * » 
oreilles uK^diocres, ovoides, un pen docoupoes a Icnr herd exterleur, sans lobe on 
prolongement en avant; tragus en feiiille de saule * * *. Dents iucisives 4 par 
paire en haut et 6 en bas; molaires 6 partout; les deux premiferes fausses molaires 
de la machoire suporieure tri's petites, courtes et pointues. 

"Pelage bicnlore partout. Jones, cotes du cou et toutes los parties snpdrieures 
d'un brun-roussfitre a base des polls noirs ; en dcssous d'un blanc jannatre h la jtoiutc 
et brun-fonco a la base * " *. 

"Longueur totale 3 ponces 5 lignes, dont la queue prend 1 ponce 4 lignes; enver- 
gure 8 ponces lignes; autibrachinm 1 ponce 4 lignes; hauteur de I'oreille depnis le 
crane jusqu'an bout 5 lignes; * * *. 

"Pairie, L'Am(5rique sci)tentri()nale, dans les environs de Philadelpbie et de New- 

'^The original description is as ft)llow8: 

"2. Vesp[ertiUo1 carolinensis. Le vespertilion de la Caroline est nioius grand (|ne 
Iepr6c6deut [' r. mnrinns' ], mais d'ailieurs il Ini ressemble beaucoup. II a ses oreilles 
et oreillons de meme forme et de mcmc dimension relative; son jioil est anssi dedeux 
couleurs, cendre-noirati-e d'abord et brnn-marron h la pointe. L'extrcmitt? des poils 
est en dessous d'un jaun(^ tirant sur le ventre; enlin les oreilles sont garnies de poils 
dans presquo L'l moitie de leui- longnenr. <t l-i qurue a nue petite portion (|ni u'est 
)ias euveloppee par la membrane iuterfemorale. Ces considerations reunies a cellea 


liis recent monograph lias applied the uaiue carolinensis to the Georgian 
bat {Fipistrellns subjfavus), but there is no reason to doubt that Geof- 
froy's animal was the large brown bat. The head and skull are both 
figured, the former on PI. I, the latter on PI. II. These are only a trifle 
smaller than the head and skull of Ves2)ertilio serotinus figured on the 
same plates, and very much larger than the figures of the head and 
skull of Pipistrellus iripisireUus^ a species of about the same size as F. 
suhjiavus. The teeth are very indistinctly shown in the figure, but in 
the two copies which I have examined^ I can find no indication of the 
second upper premolar of J'ipistrelhis. 

Chrysonotus (Vespertilio). J, A. Allen, Bull. Am. Mus, Nat. Hist., 
N. Y., VIII, p. 240, November 21, 1896. VesperHUo chrysonotus J. A. 
Allen, from Kinney Ranch, Wyoming, is a pale example of Myotis 
evotis (H. Allen), with mutilated tail. (See p. 80.) 

Ciliolabrum (Vespertilio). Merriam, Proc. Biol. Soc. Washington, IV, 
p. I, 1886. Vespertilio ciliolabrum, Merriam, is the oidy name based on 
the pallid race of Myotis californicus inhabiting the plains of South 
Dakota, Kansas, and Texas. The type was taken at Banner, Kansas. 

Cinereus (Vespertilio). Beauvois, Catalogue Baisonne du Museum de 
Mr. C. W. Peale. Philadelphie, p. 18, 1796. VespcrtU'to cinereus 
Beauvois (originally misspelled lincreus) is the first name based on the 
hoary bat, Lasiurus cinereus. The description is so detailed and accu- 
rate as to leave no doubt as to the animal that Beauvois had in mind.^ 
The type came from Pennsylvania, somewhere near Philadelphia, where 
the species undoubtedly occurs during migrations. 

Crassus (Vespertilio). F. Cuvier, Nouv. Ann. Mus. d' Hist, Nat., Paris, 
I, p. 18, 1832. I can not identify F. Cuvier's Vespertilio crassus. The 

tiroes de la teinte differonte dii pel.age, m'ont paru dtablir avec assez de certitude la 
non-ideiitito d'fspf'cc de cc vespertilion avec le 7n>triniis ; c'est ce qii'indiqnent en 
outre les pioiioitioiisdii crane. Le chanfrein est ])liis court et plus largo dans Ic ves- 
pertilion de la Caroline. Eu voici les dimensions: longueur du corps, (jl millimetres; 
lie la (juene, 28; de I'envcrgure, 259. 

"Cette espece n'a point encore 6t6 ddcrite: elle m'a etc remise par M. Bosc, (|ui se 
Test procurt^e lors de son scjour i\ la Caroline. Ce savant naturaliste a bieu vonlu 
ui'informer qu'elle y est excessivement coumiune. On la reconnoitra anx caracteres 
suivans: Orcilles ohh>n[/iics, de hi loufjiienr de la trie, reliics en part'ie; oreiUon tn dcml 
cu'itr. Pelade d'un bniu niarron en drssiis, jaiindtre oi dcsnoiis." 

'In the Harvard College library, Cambridge, Mass., and in the Smithsonian library, 
Washington, D. C. 

•17. Cliauve-souris grise. Deux premieres <leuts superienres fort petites A: pen 
apparentes. Tete blanehatre; oreilles roudes, plates, blanches, le pouitour noir, une 
appendice a la base. Polls du corps gris, vers la base ; noirs vers la pointe &, hlaucs 
a I'cxtremitt?; de sorte que ranimal a Fair d'etre mouchete, de blanc. Cos polls 
s'etendentjusqne sur la membrane qui enveloppe la queue. La membrane ailifonno 
est »?galement velue en dessous a la partie anterieure, aiusi qu'au dessus a la base de 
I'ongle saillant. Cettc membrane est environ une fois plus graude que dans I'espece 
precedente [I'espertillo fiisrus'}. FA\e a de donze a quatorze ])ouces d'envergeure. 
Le.s nariues scut emargiuees. 

(irey Bat. FespertUio linereus [sic]. 

Elle ne .se trouve point dccrite diins les auteure. Cette chauve-Souris se trouve 
dans la Pensilvanie. 


animal maybe Ni/cHceius humrrali.s^ but tbere is iiotbing in tbe original 
description' to indic;ate tliis witb certainty. Fortunately tbe name is 
not needed as all tbe species now known to inbabit tbe eastern United 
States were already named at tbe time wben it was publisbed. 

Creeks (Vespertilio). F. Cuvier, Nouv. Ann. Mus. d'Hist. Nat., Pari-, 
I, p. 18, 1832. Vcsjjertilio creels F. Cuvier is anotber unidentifiable 
species. Le Conte, bowever, wbo sent tbe type specimen to Cuvier, 
states tbat tbe animal is tbe same as Ni/eticea crrpusculari-s Le Conte 
{^=^N. Jill mend is llatinesque). IS^otbing in tbe original description- con- 
tradicts tbis assertion. 

Crepuscularis (Nycticea). Le Conte, MoMurtrie's Cuvier, Animal 
Kingdom, I, p. 131, 1831. Tbis bat is tlie Xycticeins humeraUs of liatiu- 

Cubanus (Vesperus). Gundlacb, Monatsber. K. Preuss. Akad. Wiss., 
Berlin, p. 150, 186L The descrii)tion of tbis species indicates a 
Nycticeius closely related to N. humeralis. As I bave seen no Cuban 
specimens, I am unable to say wbetber tbe animal is specifically distinct 
from tbe mainland form (see p. 121). 

Cubensis (Scotophilus). Gray, Ann. Nat. Hist., IV, p. 7, 1839. >>coio- 
'pliihtH cuhcnsl,s Gray is evidently tbe Cuban VtHpertUio. Tbe original 
description is as follows: 

Fur blackish brown (in spirits); win>j:8 dark, blackisli; nnrtor.side of the inter- 
fenioral membrane whitish, with scattered hairs; feet hirge; heel bono short, taper- 
ing; ears moderate, entire; tragus ovate-lauceolate. Body and head 2|; tail V\; fore 
arm If. Hab. Cuba. 

Tbis is the first name based on tbe animal to wbicb it refers. 

Cyanopterus (Vespertilio). Kafines(jue, American Montbly Mag., Ill, 
J). 415, 1818. lvafines(iue's Vespertilio eijanopierns can not be identified 
witb any known bat. Tbe original description is as follows: 

Tail one-third, 2 iucisores above, fi beneath, body dark gray above, bluish gray 
beneath, wings of a dark bluish gray, shafts black, ears auriculated, longer than 
the head. Length 3 inches, breadth 10. 

'Ala tcte des Murinoides, deux fausses molaires auomales de chaque cote des deux 
machoires; I'oreille obtuse el Toreillon en couteau. 

Tontes les jtarties supi'^rieures du corps sont d'nn brun-marron grisatro, et les ]iar- 
ties inforieures blondes ; les polls, a leur origine, sont plus fonces qu'a h-ur extr(5mit.\ 

Des moTistaches garnissent les cotes de la Itivre supdrieure et rextr(5mit6 de la 
machoire infcricure. 

Longueur du corps, du bout du a Torigino de la queue, 2 pouces; de la 
queue, 1 ponce 8 lignes; euvergure, S pouces S lignes. 

Cette espece est due a M. Lesueur, qui I'a envoyce de New-York, sous le uom (pie 
je lui ai conserve. 

'5» Le V. Creeks, V. Creels. 

A la tete du Serotinoides, point de fausses molaires auomales a la machoire supe- 
rienre, et une seule arinferieure; I'orielle est echancree, et I'oreillon en couteau; les 
parties supdrieures sont d'un bruu Jauuatre, les parties inferieures d'un gris sale, les 
polls de toutes ces parties sout noirs a leur base. Des moustaches garnissent les cotds 
du museau et le dessous de I'extremite di; la mAchorio inferieure. 

Longuer du corps, du bout du museau a I'origiue de la queue, 2 pouces; de la 
queue, 1 pouce 6 lignes; euvergure, 9 pouces. 

De G^orgie. Dfi aiix recherches de M. li' major Ijcconte. 


Cynocephalus (Nycticea). Le Coute, McMnrtrie's Cuvier, Animal 
Kingdom, I, p. 432, 1831. Tliis is a free-tailed bat, the common Nyc- 
tinomus of the southeastern United States. 

Domesticus (Vespertilio). Green, Donghty's Cabinet of Natural His- 
tory, II, p. 290, 1832. The description refers without much doubt to 
Myotis lucifugus Le Conte, named only one year previously. Type 
locality a village in western Pennsylvania near a stream which enters 
the Ohio a few miles from Pittsburg. 

Dutertreus (Vespertilio). Gervais, in Eamon de la Sagra's Tlist. de Tile 
de Cuba, Mamm., p. G; Atlas, Tome II, 1840. This is VeapertUio fus- 
cus cuhcnsis (Gray), as shown by the number of teeth, 32, and by the 
size, forearm 47 mm, 

Erythrodactylus (Vespertilio). Temrainck, Monographies de Mamm., 
IT, p. 238 (13me Monogr.), 1835-41. Temminck describes his Vefsper- 
tilio erythrodactylus as a bat with short, roundish ears, long tail, inter- 
femoral membrane hairy on basal half above, four upper incisors, and 
general reddish-brown color.' 

This is a combination of characters normally possessed by no known 
North American bat. The type is said to have come from the neighbor- 
hood of Philadelphia. It is probably Pipistrellus suhfJarus reddened 
by alcohol (see p. 8). 

Evotis (Vespertilio). H. Allen, Monogr. North Am. Bats, p. 48, 1864. 
This is the first name for the large eared Mi/otis of the western United 

Exilis (Vespertilio). 11. Allen, Proc. Acad. Nat. Sci. Phila., p. 283, 
1866. Vespertilio exilis is a synonym of Myotis californicus. The type 
came from Cape St. Lucas. 

Frantzii (Atalapha). Peters, Monatsber. K. Preuss. Akad. Wiss., 
Berlin (1870), p. 008, 1871, Peters's Atalapha frantzii from Costa 
Rica is the small, scantily furred southern race of Lasiurus horealis. 
It had previously been described as Atalapha mexicana by Saussure. 

'Taille nioiiulre que la pipisireXle. Tout rantibracliiuiii, la base des doigts ot la 
inciiibrane iutcrtligitale da premier doigt ron<;eatre; les autros membranes noires. 
Oieilles poiliies depiiis la base jns(iu'a plus de moitie de la loujiueur, petites ovoides ; 
tragus cu I'euille do saule; queue tres lougue a graud bout libre; membrane iuter- 
ff'inorale en dessus moitio poilue; par dcssous, rayoe de ^eines en losange, d'ou nais- 
sent des soies tr.-s oonrtes disposoos a claire-voie. Dents ineisives 4 par paire en 
liaut et 6 en bas; uiolaires 5 partout, vsenleuRut line fausse molaire a la macLoire 

I't'lage ]f)ng, fin et soyeux; en dessus tricolorc, an dessous bicolore. Toutes les 
parties Buporieures d'une teinte brune-rougeatre; mais un pen jaunatre a la tote et 
an ecu ; les poils dtaut noirs a la base, puis JauuAtre et le bout brnn-rougeatre ; moitie 
do I'iuterfonuirale tr^s poilue; en dessous bruu foucc a la base et brun-roussatre an 
bout; membranes des tlancs et iuterfemorale couvertes de poils rares. 

liOngueiir totale 2 ponces 10 lignes ou 3 ponces pour maximum, dout la queque 
piend 1 ponce 4 lignes; antibrachinni 1 ponce 2 ligues : euvergurc 7 ponces G lignes 
on 8 ponces an maximum. * * ■ 

I'atrie. L'Amerique septentriouale dans les environs de Philadelphie. 


Funebris (Lasiurus), ritziiiger, Sitzmigsber. K. Akad. Wiss., Wien, 
Iste Abth., LXII, p. 40, 1870. Lasiurus funebris Fitziiiger, based on 
the XycticeJKs norehoracensis of Temuiinck,' from Tennessee and ]\Iis- 
souri, is a synonym of Lasiurus horealis (Miiller), as shown by the 
reference to the reddish-brown color and wliite shoulder spot. 

Fuscata (Atalapha). Eafinesqne, Annals of Nature, p. 2, 1820. IJafi- 
nesque's Atalapha fuscata can not be identilied. The original descri[)- 
tion is as follows: 

Ears loiigers than the head, anriculated and blackish; tail three-sevenths of total 
length, jutting only hy an obtuse point; body bro^Ynish above, grayish beneath 
shoulders and cheeks dark brown ; hind feet blackish, hairy above; "wings blackish 
brown. — Found in the northern j^arts of the state of New York and in Vermont. 
Total length three and an half inches. My genus Atalapha (Prec. dec.) contain all 
the Bats without fore teeth ; there are 3 or 4 species of them in tiie United States all 
blended under the name of VespcrtiJio (or KnctiUo) novehoracensis by the writers. 

Fuscus (Vespertilio). Beauvois, Catalogue Eaisonne du Museum de 
Mr. C W. Peale. Philadelphie, p. 18, 1796. Vespertilio fuscus 13eanvois 
is the first name based on the common brown bat of the eastern United 
States.2 The original description is faulty, as it contains a glaring 
error with respect to the number of upper incisors, which are said to ho 
only two. Nevertheless there can be no doubt as to the animal that 
Beauvois intended to describe, since only one brown bat of the size of 
Mijotis myotis ('la chauve-souris ordinaire de France') inhabits the 
region about Philadelphia. 

Georgianus (Vespertilio). F. Cuvier, Nouv. Ann. Mus. d'Hist. Nat., 
Paris, I, p. 1(5, 1832. The specific name //eor///rf^r?;.v long- passed current 
for the small ripistrellus inhabiting the^astern United States. In 1893 
H. Allen substituted for it the older name carolinensis Geoft'roy. As 
already shown, however, there can be no doubt that Geoft'roy's animal 
was Vespertilio fuscus. It is equally certain that Cuvier's name can 
not be applied to the Georgian bat, since his description probably 
refers to a Myotis, while in the same paper Cuvier accurately describes 
the Georgian bat as Vrspcrtilio suhfarus. Le Conte, wlio collected the 
specimens on which several of Cuvier's siiecies were based, describes 
the Georgian bat under the name georgianus," find expressly states that 

'Monographles de Manimalogie, II (13me Monogr.), p. 1.58. 

-16. Chauve-souris brune. Deux preiuiires dents snperieures, distantos Tunc de 
I'autre, & voisines des canines, une fois plus courtes que ces dernii'res: orcilles nues, 
noiratres, ov.ales, avec un appondice a leur base; queue prcs(|u'aussi longuequole 
corps (la tt'te excepte) memltrune ailiforme noiratre: polls du corps bruns en dessus, 
grisatres en dessotis. 

Brown bat. Vesprrillio fuscus. 

Cette Chauve-souris est la plus commune que Ton tronvcdans les enviroAS deriiil- 
adelphie. Ella ressemblc bcaucoup a la chauve-souri.s ordinaire de France, niaiti cu 
difftro cssentiellement par )c nombre des dents de la. m.achoire supc^rieure. 

^Proc.Acad. Nat. Sci. Thila.. VII (1851-5.-)), p. 131, 185(1. 


this was tlie animal that tlic riciich autlior had in hand. The evi- 
dence is so strongly against this view that Le Conte's statement may be 
safely disregarded.' 

Greenii (ScotopMlus). Gray, List Spec. Mamm. Brit. Mus., p. 30, 1843. 
Gray's ScotopMlus greenii is a nomen nudum which refers without much 
doubt, however, to Vespertilio fuscus. The name is introduced as fol- 
lows: "Green's Bat. Scotophilus Greenii. a In spirits. — N^ortli 
America. Presented by Jacob Green, M.D." 

Gryphus (Vespertilio). F. Cnvier, Nouv. Ann. Mus. d'Hist. Nat., T, p. 
15, 1832. Dr. Harrison Allen has recently used the name '■yesperiiUo'' 
(jryplius for the ' T.' lucifuyus and 'F.' ftuhuJatus of his first monograph 
which he unites as subspecies.'^ The combination of characters; two 
premolars in each jaw, light yellow color, aiul hairy lips,^ is not known 
in any bat inhabiting the eastern United States. Hence the description 
is wholly undetenninable. Le Conte refers the name to Vespertilio fus- 
cus,^ but this determination is very doubtfnl. 

Henshawii (Vespertilio nitidus). U. Allen, INFonogr. Bats N. Am., p. 103, 
1893. VcHpertiJio nitidus hcnshan-ii 11. Allen is a synonym of Myofis 
eaUfornicus, based on pale examples of the latter from near Wingate, 
N. Mex. 

Hesperus (ScotopMlus). H. Allen, INIonogr. N. Am. Bats, ]>. 43, 1864. 
This is the first name based on the common Pipistrelliis of the south, 
western United States. 

Humeralis (Vespertilio). Bafinesque, Americau Monthly Mag., Ill, 
p 44."), 1818. While there is nothing absolutely diagnostic in the original 

'The ()ri.i:; description of Vespertilio georgianus is as follows: 

"Ala t(*te (lea MuriiioTdes; I'oreille est dchancrt^e et Foreillon en ali'iio. Toiitcs 
les parties siiporieures du corps sont colorccs par nn melange do iioir et de blond 
jauni'itre. Le noir i)aroit, parccqiie la pointe despoils qui est blonde ne recouvre 
pas, a cause de sa brevitc, lo reste do la longueur dc ces polls qui est noir. Les par- 
ties iuferieures sont grises, niais molauge'es de noir, par la nu'ino cause qui fait 
paro'itre cette couleur aux parties supi'rieures. Des moustaches garuissent les cAtrs 
des li'vres superieures, ot le dessous de rextremitc do la iiiachoire inferieure. 

"Longueur du cori»s, du bout du uiuseau a I'origiue de la queue, 1 pouce G lignes; 
dc la queue, 1 pouce 2 lignes; envergure, 7 ponces. 

"De Goorgie. Du aux rccherches de M. le major Leconte." 

"Monogr. Bats N. Am., j). 75, 1893. 

"•The description is as follows: 

"A latete des Muriuoidoset deux fansses niolaires anomales fort petites de chaque 
cot*^. des deux machoires; I'oreille est dchancrce et roreillou en couteau. Toutes les 
parties snp(5rieures du corps sout d'un blond jaunatrc, les parties infcrieures sont 
grises, mais les polls des nns et des autres sont noirs a lour extr(^nute inferieure. Les 
parties uues sont viohUres. Des moustaches garuissent les cotes de la levre supe- 
rieuro et le dessous de rextromitc de la machoiro inferieure. Longueur du corps, de 
rextremite du museau a rorigino de la (lueue, 1 pouce 9 lignes; do la queue, 1 jjouce 
2 lignes; envergure, 7 ponces 10 lignes. 

"Des environs de New York. Du aux vecherches de M. Millifrl-." 

M'roc. Acad. Nat. 8ci. Phila. Vll (1854-55), p. 134, 1856. 


description' of this species, its subsequent treatment is such as to leave 
no reasonable doubt that Raflnesque liad in mind the bat afterward 
named Ni/ctieea crcpuscularlH by Le Conte. In 1819 Raflnesque based 
the genus Nycticeius on two of liis species of Vespertilio which differed 
from all others known to him in the possession of only two incisors 
in the upper jaw. One of these, V. tesselatns, was the red bat, Lasiurus 
borealis. The other, V. humeralis, must have been the twilight bat, as 
there is nothing" in tlie description that precludes it, and no other small 
si)ecies with two ui)per incisors is known in the eastern United States. 

Incautus (Vespertilio). J. A.Allen, Bull. Am. Mus. Nat. Hist., VIII, 
]). 239, November 21, 1896. Vesperiilio iiieautus J. A. Allen, is a syno- 
nym of Myotis velifer (J. A. Allen), based on specimens of the latter 
from San Antonio, Tex. (See p. 59.) 

Intermedius (Lasiurus). H. Allen, Proc. Acad. Nat. Sci. Phila. (18G2), 
p. 14:(), 1863. This is the only specific name based on the bat now 
known ns JJasyptcrus intermedius. 

Keenii (Vespertilio suhulatus). Merriam, American Naturalist, XXIX, 
p. 800, September 1, 1894. W'sjK-rtilio .siibidafiis keenii is the only name 
based on the dark form of Myotis snhnlatus occurring on the Queen 
Charlotte Islands, Uritish Columbia. 

Lanceolatus (Vespertilio). ^^aximilian, Reise in das Innere Nord- 
America, I, p. 364, footnote, 1839. The specific name lanceolatus was 
proposed Dy Maximilian as a substitute \'ov sn hn lain s, shon\d the animal 
which he designated by the latter name i)iove to be different from 
Say's.'^ Maximilian's siilmlatus is described at considerable length and 
is probably the VespertiUo Ineifnr/ns of Le Conte. The following meas- 
urements are given: Total length. 3" V"; extent, 8" 9'"; tail, 1" 3'"; 
ear, 0'"; tragus, 2.^". 

Lasiurus (Vespertilio). Schreber, Siiugthiere, Abth. I, PI. LXII B, 
published with Abth. IV, I left 34, 1781.'' The figure of Vespertilio 
lasiurus is a good representation of the red bat (Lasiurus horenlis Mid- 
ler, 1776). Dobson^ cites this name as dating from 1775, in which case 
it would be the earliest for the species. This is, however, a mistake. PI. 
LXII appeared with Abth. I in 1774, but PI. LXII B, was not pub- 
lished until 1781 with Abth. IV, Heft 34. The species is mentioned in 
Abth. I (p. 170) as 'Die nordamerikanische Fledermaus.' 

Lasurus (Vespertilio). Boddaert, Elenchus Animalium I, p. 71, 1785. 

'Tail tluee-seM!ntli8, upper incisores 2, remote, lower 6, body dark brown above, 
slioulders black, ,i;ray beiieatb, wiugs, tail, ears, and snout blackisb, eyes under tlio 
bair, ears longer tban tbe bead, elliptical, anriculatod. Lengtb 3 1-2 inches, 
breadth 11. 

-Diese Fledermaus bescbrieb icb in nieinem Tagebucbe nnter der Benennnng leap. 
Janceolaina, sie bat abcr viel Aebnlicbkeit mit Say's V. fiiihiihitns. Zu Betblelieni in 
Peuusylvanien erbielt icb zwei Excniplare * * * _ 

^For date of publication see Sberborn, Proc. Zool. 8oc. London, 1891, p. 589. 

■•Catal. Chiroptera Brit. Mus., p. 269, 1878. 


Vcsju'iiilio hisnrus Boddaertis probably a misprint for V. hi,sinri(.s, siuco 
reference is made to tSclireber's plate. ^ 

Lecontii (Plecotus). Cooper, Ann. Jjyceiim Xat. Hist. New York, IV, 
}), 72, 1848. Concerning" Plecotus lecontii, Cooper says: 

The uauie inacroiis 1 have venturetl to supersede, as being in nowise distinctive of 
the species, but in reality derived from a generic cliaracter, which in some species 
is more developed than iu tlie present. Tiie ears Ijeing therefore rather miudl for the 
genus, this name becomes contradictory ; and no American naturalist will regret the 
op])ortunity thus afforded of paying a well merited tribute to the discoverer of so 
many rare and remarkable animals of this country. 

The name is of course a synonym of macrotis Le Conte. 

Leibii (Vespertilio). And. .S: Bach.. Jonrn. Acad. Nat. Sci. Pliila., 
VIII, rt. II, p. 281, 1842. Vespertilio leibii And. & Bach., from Erie 
County, Mich, [now Ohio] is probably Myotis lucifuffus Le Conte. The 
measurements are as follows: " Length of head and body 1 inch 7 lines; 
tail 1 inch 4 lines; spread 7 inches; height of ear posteriorly 2.] lines; 
tragus I line." 

Longicrus (Vespertilio). True, Science, VIII, oSTo. 20.3, p. ."iS8, Dec. 24, 
1886. Vespertilio loiujicrus True, is the only name based on the com- 
mon western subspecies of Myotis sithulatKs. 

Lucifugus (Vespertilio). Le Conte, MclMurtrie's Cuvier, Animal King- 
dom, I, !>. 431, 1831. The original description of Vespertilio lueifwjus 
Le Conte is as follows: 

Anterior upper fore-teeth bilobate; body above dark brown, beneath cinereous; 
nose sub-bilobate; face with a nakedish prominence on each side; ears oblong, 
naked, tragus sub-linear, half as long as llie ears; tail projecting a little beyond the 
membrane; length to the insertion of the tail two inches and a quarter; tail one 
inch and a quarter. 

From this alone it would be impossible to identify the animal that 
the writer had in mind. Fortunately, Le Conte treated the species in 
more detail in a paper published in the Proceedings of the Academy 
of Natural Sciences of Philadelphia for 1855 (pp. 431-138). Here he 
recognizes three species of ' VespertiHo'' with thirty eight teeth as occur- 
irng in the eastern United States. These are V.subulatus, V.lncifuijus, 
and Y. (/corf/ianiis. V. (jcorgianHs is clearly Pipisirellns suhflarKs, which 
Le Conte placed with the thirty-eiglit-toothed species through an error 
in counting the teeth. P. lucifugus and V. snbulatHS of Le Conte are 
evidently based on individual variations in the shorter-eared of the two 
eastern species of 4///o/ /.v. The only differences in Le Confers descrip- 
tions of the two forms are the following: P. subulatns: Ear slightly 
emarginate; length 2.0; tail 1.1; extent 9.4; head .9; ears .4; oriUon 
.3. V. IncifiKjus: Ears so much emarginated as to appear hooked; 
length 3.8; tail l.C; extent 11.7; head .75; ears .45; orillou .2. 

' Boddaert's account is as follows: 

" Lasurus. 16. V. cauda longissima, rostro oblicjuo truncato, hi Joufjne (Jiieite. 
Schreb., tab. 52. B lomjtaUed Bat." 

Habitat: "Quare Doct. Krxlebeu, Zimmermauu, Pennant hune notabilem vesper- 
tilionem omiserunt, mihi latet." 


Macleayii (Scotophilus). (iray, List Spec. Maiiim. Brit. Mus., p. 80, 
1843. i^c'otopliilii.s iii<iclc(ii/ii Gray is a iioineii iiuduiu, probably based 
on YesperiUio i'uHvns cubeusis. Gray says merely: "MacLeay's Bat. 
SooTorHiLUS MacLeayii a In spirits. Male. Cuba. — Presented by 
W. S. MacLeay, Es(i.'' 

Macropus (Vespertilio). H. Allen, Proc. Acad. Nat. Sci. Pliila,, p. 288. 
1866. Vespertilio macropiis H. Allen is a synonym of Myotis yumaneum 
(H. Allen). Tbe name is, moreover, preoccupied by Vespertilio macropus 
Gould, 1854.' 

Macrotis (Plecotus). Le Coute, McMurtrie's Cuvier, Animal King- 
dom, 1, !>. 431, 1831. Plecotus macrotis Le Oonte is the first name cer- 
tainly applied to tlie bat now known as Corynorhinus macrotis. 
llafinesque's Vesiurtilio megalotis may have been the same animal, but 
his description is so poor that it is impossible to determine what he 
refers to. 

Maculatus (Histiotus). .1. A. Allen, Bull. Am. Mus. TsTat. Hist., New 
York, 111, }). 1 '.»."), 1891. Histiotus maculatus is the name under which 
the bat now known as Eiulerma m<{culatiim Mas first described. 

Megalotis (Vespertilio). Patines(|ue, American ^Monthly INIag,"., Ill, p. 
•446, 1818. There is nothing- in the original description-' of Bafines(iue's 
Vespertilio megalotis by which the si)ecies can be identified. It is pos- 
sibly tlie animal afterwards named Plecotus macrotis by Le Conte. 

Melanops (Eptesicus). Kafinesque, Annals of Nature, p. 3, 1820. 
When Kafinesque transferred his Vespertilio phaiops to the geiuis 
Eptesicus^ he clianged the specific name to melanops, thus adding 
another to the synonyms of Vespertilio fuscus. 

Melanorhinus (Vespertilio). Merriam, North American Fauna, No. 3, 
p. 40, September 11, 1890. Vespertilio melanorhinus Merriam is a syn- 
onym of Myotis calij'ornicus, based ou a specimen of the latter from San 
Francisco Mountain, Arizoiui. 

Melanotus (Vespertilio). liafiuesque, American Monthly Mag., Ill, p. 
445, 1818. Ivafines(iue's Vespertilio melanotus is hopelessly indetermi- 
nable. The original description is: 

Tail oue-tliird, brown iibove, gray Ijeueath, body aljove, whitish beueath, 
wing.s dark gray, shafts black, ears aiiriculated, rouuded. Length 4 1-2 inches, 
breadth 12 1-2. 

Melas (Eptesicus). Le Conte, Proc. Acad. Nat. Sci. Phila.,yil (1854-55), 
p. 438, 1856. In a paper on the bats of the United States published in 
185(5, Le Conte refers to Eptesic^is melas Rafinesque as an unidentified 
species. I have been able to tind no such name in any of llafinesque's 
writings and therefore suppose that Eptesicus melas is a misprint for 
E. my das, especially as the latter is not mentioned by Le Conte. 

'Mammals of Australia, III (fide Dobson). 

-Tail three-eighths of total length, body dark gray above, pale gray beneath, ears 
very large, duplicated, auricules nearly as long. Length 4 inches, breadth 12 inches. 


Merriami (Vesperugo). Dobson, Ann. & Mag. Nat. ITist., XVIII, p. 
124, 1886. Vcspvruyo merriami Dobson, Avas based on a speciiueu of 
ripiNtrelhi.s hesperus from I{ed IJhiff, Teham