J
%r
.
AN INTRODUCTION
TO THE
STUDY OF MAMMALS
^
AN INTEODUCTION
TO THE STUDY OF
MAMMALS
LIVING AND EXTINCT
BY
WILLIAM HENBY FLOWEB
C.B., F.R.S., D.C.L., LL.D., P.Z.S., F.L.S., F.G.S., &c.
DIRECTOR OF THE NATURAL HISTORY DEPARTMENTS, BRITISH MUSEUM
AND
BICHABD LYDEKKEB
B.A., F.G.S., F.Z.S., &c.
THE Wi;iOLLY OPOSSUM
LOXDOX: ADAM AXD CHABLES BLACK
MDCCCXCI
32 L I
PREFACE
Onp: of the greatest difficulties experienced by all who undertake a
work of this nature, not professing to be an exhaustive treatise
on the subject with which it deals, is to determine the amount
of detail desirable to be introduced to meet the requirements of
the ordinary student, without rendering it too bulky or costly
for general use. The experience of those who endeavour to profit
by the book can alone decide how far the authors have succeeded
in this respect. It will be observed that in many instances certain
better-known or more interesting members of the class have been
described at considerable length, while it has been necessary to
treat others with much greater brevity.
With regard to the references to the literature of the various
groups treated of, it has been the endeavour of the authors to
make a selection of such memoirs and works as are likely to prove
most valuable to the student for the amount of original informa-
tion which they contain, and more especially of those giving
full bibliographical data up to the time of their publication, the
repetition of which has been considered unnecessary.
In a few instances new generic terms have been introduced to
vi PREFACE
replace some -which were already occupied ; these have been pro-
posed by Mr. Lydekker, and should be quoted as his.
The work is based largely upon the article " Mammalia," to-
gether with forty shorter articles, written by the senior of the two
authors for the ninth edition of the Encyclopaedia Britannica. The
account of the orders Rodentia, Insectivora, and Chiroptera con-
tributed to the article "Mammalia" by Dr. G. E. Dobson, F.R.S.,
as well as the articles "Mole," "Shrew," and "Yampyre," by the
same writer, the articles "Marmot," "Mouse," "Opossum," "Phal-
anger," "Rat," "Squirrel," "Stoat," "Vole," and others, by Mr.
Oldfield Thomas, and likewise the article "Ape," by Dr. St. G.
Mivart, F.R.S., have also been made use of to a greater or less
extent. The best thanks of the authors are due to these three
gentlemen for freely permitting the incorporation of their own
work in the present volume.
Mr. Lydekker undertook the task of arranging the various
articles in their proper sequence, selecting from these such portions
a- seemed suitable, filling up the gaps, and adding new matter
where necessary ; a large amount of this new matter treating of the
extinct forms, and also of the group Artiodactyla.
The subsequent revision, both before being sent to the printers,
and also when passing through the press, has been made by both
authors, who are thus jointly responsible for the whole work.
The illustrations are to a great extent those prepared for the
various articles in the Encyclopaedia, but many have been added
— some drawn expressly for the work, and some borrowed from
other publications. For most of the latter the authors take this
opportunity of expressing their thanks to the Publication Com-
PREFACE
mittee of the Zoological Society of London, as well as to the
individual writers in whose works they first appeared.
The authors have further much pleasure in acknowledging the
ready and obliging way in which Mr. Oldfield Thomas has,
throughout the progress of the work, placed his extensive know-
ledge of the group of animals of which it treats at their disposal.
London, March 1S91.
Corrigenda.
Page 280, for Chaeropsis read Chceropsis.
Page 292, for Chseropotamidae and Chaeropotanms read Chceropotamidie and
( 'in i r< >pi itunms.
Page 590, for Precdogale read Pcecilogale.
CONTENTS
CHAPTER I
PAGE
Introductory Remarks ..... 1
Use of term mammals, 1 ; Characters of mammals, 2 ; De-
velopment of young, 3 ; Size of mammals, 4 ; Uses and products
of mammals, 4.
CHAPTER II
General Anatomical Characters .... 7
I. Tegumentary Structures .... 7
Hair, 7 ; Colour, 8 ; Scales, etc., 11 : Nails, claws, and
hoofs, 12 ; Odour-secreting glands, 12.
II. Dental System. . . . . .13
Teeth, 13 ; Structure of teeth, 13 ; Development of teeth,
15 ; Forms of teeth, 17 ; Succession of teeth, 19 ; Arrangement,
homologies, and notation of teeth, 21 ; Dental formulae, 25 ;
Modifications of teeth in relation to function, 28 ; Taxonomy,
30 ; Trituberculism, 30.
III. The Skeleton ...... 33
Definition, 33 ; Axial skeleton, 34 ; Skull, 34 ; Vertebral
column, 39 ; Cervical vertebra;, 41 ; Dorsal vertebra;, 42 ;
Lumbar vertebra;, 42 ; Sacral vertebra;, 43 ; Caudal vertebra;,
43 ; Sternum, 44 ; Ribs, 44 ; Appendicular skeleton, 46 ;
Anterior limb, 46 ; Shoulder-girdle, 46 ; Brachium and Ante-
brachium, 47 ; Manus, 48 ; Carpus, 48 ; Metacarpus and Phal-
anges, 49 ; Posterior limb, 50 ; Pelvic girdle, 50 ; Thigh and
Leg, 51 ; Pes, 52.
IV. The Digestive System . . . . .53
General considerations, 53 ; Mouth, 54 ; Salivary glands.
55 ; Stomach, 57 ; Intestinal canal, 59 ; Liver, 60.
V. Circulatory, Absorbent, Respiratory, and Urinary Systems 63
Blood, 63 ; Heart, 63 ; Lymphatic vessels, 65 ; Ductless
glands, 65 ; Xostrils, 66 ; Trachea, 67 ; Larynx, 67 ; Diaphragm,
67 ; Lungs, 68 ; Air-sacs, 68 ; Urinary Organs, 69 ; Bladder, 69.
CONTENTS
PAGE
VI. Nervous System and Organs of Sense . . .69
Brain, 69; Nerves, 71; Sense of touch, 72; Taste and
smell, 72 ; Sight, 72 ; Hearing, 73.
VII. Reproductive Organs . . . • .74
Testes, 74 ; Penis, 74 ; Ovaries and oviduct, 75 ; Mammary
glands, 75 ; Secondary sexual characters, 76 ; Placenta, 76.
CHAPTEE III
Origin and Classification of the Mammalia . . 82
Origin, 82 ; Classification, 84 ; Table of orders and
families, 88.
CHAPTER IV
Geographical and Geological Distribution . 93
I. Geographical Distribution . . • .93
Zoological regions, 96 ; Palsearctic region, 97 ; Ethiopian
region, 9S; Oriental region, 100; Celebes, 102; Nearctic region,
102 ; Neotropical region, 103 ; Aquatic mammals, 104.
II. Geological Distribution . . . .107
Sequence of strata, 107 ; Mesozoic mammals, 109 ; Multi-
tuberculata, 109 ; Polyprotodont types, 113 ; Tertiary mammals,
115.
CHAPTER V
The Subclass Prototheria or Ornithodelphia . 117
General characters, 117. Family Ornithorhynchidje,
119; Ornithorhynchus, 119. Family Echidnidje, 124;
Echidna, 125 ; Frocchidna, 126 ; Fossil species, 127.
CHAPTER VI
The Subclass Metatheria or Didelphia . . .128
General characters, 128 ; Distribution, 131 ; Classification,
131.
Suborder Polyprotodontia . . . • .133
Family Didelphyid.e, 133; Chironectes, 134; Didelphys,
135. Family Dasyuriixe, 136 ; Subfamily Dasyurinre. 136 ;
Thylacinus, 136; Sarcophilus, 137; Dasyurus, 138; Phascolo-
gale, 139; Sminthopsis, 139; Antechinomys, 139; Subfamily
Myrmecobiina?, 140; Myrmccobius, 140. Family PeramelhXE,
141 : I'< nancies, 142; Fcragalc, 143; Chmropus, 143.
CONTEXTS xi
PAGE
Snhonlr DlPROTODONTIA . . . . .144
Family PHASCOLOMTIDJS, 144; Phascolomys, 145; Phascol-
onus, 146. /-W/// //// Pn ai..vn<;i: km>.k, 1 17; Subfamily Tarsipedinae,
148; Tarsipes, US; Subfamily Phalangerinse, 149 ; Phalanger,
149; Trichosurus, 150; Pseudochirus, 151; Pctau routes, 152;
Dactylqpsila, 152 ; I'etaunis, 153 ; Gymnobelideus, 154 ;
Dromicia, 154 ; 1'islaeliuriis, 155 ; Acrobatcs, 155 ; Sub/amity
Phascolarctinse, 155 ; Phascolarctus, 156. Extinct Phal-
angeroids, 157 : Thylacoleo, 157. Family Macropodid;e,
158 ; Subfamily Hypsiprymnodontinse, 162; Hypsiprymnodon,
162; 2Wcfts, 162; Subfamily Potoroinse, 162; Potorous, 163;
Bettongia, 163 ; Calqprymnus, 164 ; dSpyprymnus, 164 ; *S*«6-
family Macropodinse, 164 ; Lagostropkus, 165 ; Dendrologies,
165 ; Dorcopsis, 166 ; Lagorchestes, 166 ; Onychogale, 166 ;
Petrogale, 167 ; Macropus, 167 ; Extinct genera, 170. Extinct
Families, 171 ; Diprotodon, 171 ; Nototherium, 171.
CHAPTER VII
The Subclass Eutheria and the Order Edentata . . 173
General characters and classification of Eutheria, 173.
Order Edentata . . . . . .176
Family Bradypodid.e, 179 ; Bradypus, 181 ; Gholcepus,
182 ; Nothropus, 1S3. Family Megatheriid^e, 183 ; Mega-
therium, 185 ; Scelidotherium and Mylodon, 188 ; Promega-
therium, 189. Family Myrmecophagid^e, 190 ; Myrmecophaga,
190; Tamandua, 192 ; Gycloturus, 193. Family Dasypodid^e,
194 ; Subfamily Chlamydophorinse, 196 ; Chlamydophorus, 196 ;
Subfamily Dasypodinae, 197; Dasypus, 197; Xenurus, 198;
Priodon, 198 ; Tolypeutcs, 199 ; Subfamily Tatusiinne, 200 ;
Tatusia, 200 ; Extinct genera, 201. Family Glyptodontid^;,
202. Family Manid2E, 204; Manis, 204; Palceomanis, 208.
Family Orycteropodid.e, 208 ; Orycteropus, 208. Biblio-
graphy, 211.
CHAPTEE VIII
The Orders Sirenia and Cetacea . . .212
Order Sirenia . . . . . .212
Fa mill! Manatid.e, 215 ; Manatus, 215. Family Hali-
COKID.E, 220 ; Halicore, 220. Family Rhytinid.e, 221 ;
Rhytina, 221. Extinct Sirenian.s, 222 ; Halitherium, 222 ;
Other forms, 223. Bibliography, 224.
Order Cetacea ...... 225
Suborder Mystacoceti ...... 234
Family Bal^eniDjE, 234 ; Balcena, 236 ; Neobalcena, 241 ;
Ii'hachianectes, 241 ; Megaptera, 241 ; Balcenoptero, 242 ; Extinct
genera, 245.
CONTENTS
Suborder Arch^eoceti . . . . • .246
Family Zeuglodontid.e, 246 ; Zeuglodon, 246.
Suborder Odoxtoceti ...-•• 247
Fa, nil, i 1'hyseterid.e, 247 ; Subfamily Physeterinse, 248 ;
Physeter, 248 ; Cogia, 250 ; Extiuct physeteroids, 251 ; Sub-
family Ziphiinse, 251 ; Eyperoodon, 252 ; Ziphius, 254 ; Meso-
plodon, 254: Berardius, 256; Choneziphius, 257. Family
Squalodoxtid.e, 257; Squalodon, 257. Family Plataxistii>.e.
257; Platanisia,25S ; Inia,259; Pontoporia, 259; Fossil forms,
259. Family'DmssBXSiDM t 2&(i\ Monodon,260; DelpMnapterus,
262; Phoccena, 263 ; Cephalorhynchus, 266 ; Orcella, 267; Orca,
267 ; Pseudorca, 268 ; Globieephalus, 26S ; Grampus, 270 ;
Feresia, 270 ; Lagenorhynchus, 270 ; Delphinus, 271 ; Tursiops,
271 ; Prodelphinus, 271 ; Stewo, 271 ; Sotalia, 272. Biblio-
graphy, 272.
CHAPTER IX
The Order Ungulata . . ■ .273
Ungulata Vera . . . • .275
Suborder Artiodacttla . . . . .275
Suina, 278. Family Hippopotamidje, 278 ; Hippopotamus,
278. Family Suid.e, 281 ; Sus, 281 ; Babirusa, 2S7 ; Phaco-
chcerus, 288. Family Dicotylid.e, 289 ; Dicotyles, 289 ;
Hyotherium, etc., 291. Extinct Transitional Artiodactyles,
292 ; Choeropotamidae, 292 ; Anthracothermhe, 292 ; Meryco-
potamus, 293 ; Cotylopidse, 293 ; Anoplotheriidse, 293 ; Caeno-
theriidre, 294; Dichodontidse, 294. Tylopoda, 295. Family
Camelidjs, 295; Camelus, 296; Auehenia, 298; Extinct
Cameloids, 303. Tragttlina, 305. Family TRAGULmae, 305;
Tragulus, 305; Doreatherium, 306; Extinct Traguloids, 306.
Pecora, 307; Antlers, 308; Horns, 310; Teeth, 310; Stomach,
312. Family Cervid.£, 313 ; Subfamily Moschinse, 314 ;
Moschus, 314 ; Subfamily Cervinse, 316 ; Plesiometacarpalia,
316 ; Cervulus, 316 ; Elaphodus, 318 ; Ccrvus, 319 ; Telemeta-
carpalia, 323 ; Sangifer, 324 : Alces, 326 ; Cervalces, 327 ;
Capreolus, 327 ; Hydropotes, 328 ; Cariacus, 329 ; Pudua, 330 ;
Extinct genera, 330. Family GlRAFFlD.dE, 330 ; Giraffa, 331 ;
Allied extinct types, 332. Family Antilocapridje, 333 ;
Antilocapra, 333. Family Boyid^;, 334 ; Alcelaphus, 334 ;
Connocluctcs, 336 ; Cephalophus, 338 ; Tetraceros, 338 ; Neo-
tragus, 338 ; Nanotragus, 339 ; Pelea, 339 ; Cobus, 339 ; Cervi-
capra, 340 ; Antilope, 340 ; JEpyccros, 341 ; Saiga, 341 ;
Pantholops, 341 ; Gazella, 341 ; Hippotragus, 343 ; Oryx, 343 ;
Aiidax, 345 ; Boselaphus, 345; Tragelaphus, 346; Strepsiceros,
347 ; Orcrts, 348 ; Extinct types, 348 ; Rwpicopra, 349 ; A'-
rlfdus, 350 : Eaploceros, 351 ; Budorcas, 351 ; C«p-«, 352 ;
Ovi's, 354 ; Ovt'&os, 357 ; Bos, 360.
CONTENTS xiii
Suborder Perissodactyla ..... 368
Family Tai'h:ii>.k. 370 ; Tapirus, 370 ; Palceotapirus, 373.
Family LoPHiODONTiD.fi, 373. Family 1' \i..i:< n n i.i: iid^e, 375.
Family Equip-e, 376; Protohippus, 3S0 ; Hipparion, 380;
Equus, 381. Family Rhinocerotid^, 402; Rhinoceros, 402;
Extincl types, 411. Families Lamupotheriipje, Chalico-
THERIID.fi, and TlTANOTHERHD.fi, 412. Family Macrau-
CHBNilD.fi, 414. Family PROTEROTHERUDfi, 414.
StTBTJNGULATA ....••• 414
Suborder Hyracoidea ..... 415
Family Hyracip.e, 41") ; Ilyra.r, 117 ; Dendrohyrax, 418.
Suborder Proboscidea ...... 418
Family ELEPHANTlDfi, 423 ; Elephas, 124 ; Mastodon, 431.
Family DiNOTHERiiDiE, 435 ; Dinotherium, 435.
Suborder Amblypoda ...... 436
Uintathcrium, 436 ; Coryphodon, 437.
Suborder Condylarthra ..... 438
Suborder Toxodontia ...... 439
Nesodon, 439 ; Toxodon, 439 ; Typotherium, 440.
Group Tillodoxtia . . • • • .441
Bibliography of Ungulates . . . . .442
CHAPTER X
The Order Kodentia ...... 443
Suborder Sijiplicidentata ..... 448
Section Sciuromorpha, 448. Family Anomalurib^e, 449 ;
Aaomalurus, 449. Family Sciurip^:, 450; Sciurus, 450;
Eh ith rose inrus, 452 ; Xerus, 452 ; Tamias, 452 ; Pteromys and
Sri it ropier us, 453 ; Eupctcinrus, 454 ; Extinct genera, 454 :
Arctomys, 454; Cynomys, 455; Spermophilus, 456; Extinct
genera, 457. Family Haplodontid.e, 457 ; Haplodon, 457.
Family Castoribjs, 457 ; Castor, 457. Section Myomorpha,
459. Family aIyoxip^e, 459; Mijoxus, 459; Eliomys, 459;
Graphiurus, 459 ; Claviglis, 460; Muscardinus, 460. Family
LoPHlOMYlDfi, 460; Loxthiomys, 460. Family Murip^e, 461 ;
Hydromys, 461 ; Xcromys, 461 ; Platacanthomys, 462; Gerbillus,
162; Pachyuromys, 462 ; Mystromys, 462; Otomys&nd Dasymys,
462 ; Molar,, mys, 462 ; Phlceomys, 462 ; Dendromys, 463 ;
Cricetus, 463; Holochilus, 464; Sigmodon, 464; BMbhrodon
and Oehetodon, 464 : Neotoma, 164 ; Hypogeomys, 465 ; Xesomys,
465 ; Brachytarsomys, 465 ; Hallomys, 465 ; Fl inrus, 465 ;
Phenacomys, 466 ; Arrimlo, 466 ; Synaptomys, 467 ; Myodes,
467; Cuniculus, 470; lifter, 470; Neofiber, 472; Ellobius,
xiv CONTEXTS
PAGK
172: Siphneus, 472; Deomys, 473; .l/c*. 173; Nesocia, 475:
Golunda, 476; Uromys, 476; Chiruromys, 476; Hapalotis,
476: Afastacomys, 476; Acanthomys, 176; Echinothrix, 477:
Typhlomys, 477 ; Cricetomys and Saccostomus, 177 ; PUhechirus,
477. Family Spalacid*, 477; Spalax, 177: Phizomys, -177:
Bathyergus, 478; Oeorychus and Myoscalops, 478; Hetero-
cephalus, 47*. Family Gku.myid^:, 478; Gcomys, 478;
Thomomys, 478 : Dipodomys, 479 ; Perognathus ami //./• romys,
479. Family Dii'oDiD-E, 479; Sminthus, 479; Zo^ks, 480;
ZMptw, 4S0 ; Alactaga, 180 : Platycercomys, 480 ; Pcdrtcs, 480.
,v. ,■/;,„/ Hystbicomorpha, 180. Family Octodontid.k. 480.
Ctenodactylus, 481 ; Peetinator, 481 ; Or/,:,/,,,,, 481 ; Habrocoma,
482; Schizodan, 482; Gtenomys, 482; Spalacopus, 482;
Petromys, 482 ; Myopotamus, 482 ; Capromys, 482 ; Aulacodus,
483 ; Plagiodon, 483 ; Lonchcres and Echinomys, As:', ; Mesomys,
483 ; Dadylomys, 483 ; Ccrcomys, 483 ; Carterodon, 484 ;
Fossil forms, 484. Family Theridhmyiile. 484. Family
ETSTEiclDiE, 484 ; Erethizon, 484 ; Synetlicres, 485 ; Chcetomys,
486 ; Hystrix, 4S6 ; Atherura, 4S7 ; Trichys, 487. F<>aiilij
Chinuhillid.e, 487 ; Chinchilla, 487; Lagidiwm and Lagosto-
mus, 488 ; Extinct genera, 488. Family Castoroidid.e, 488 ;
Castoroides, 488. Family Dasyproctid.e, 488 ; Dasyprocta,
488 ; Ccelogcays, 489. Family DlNOMYnxE, 489; Dinomys, 489.
Family Cayiid.e, 489; Oc/", 489; Dolkhotis, 490; Hydro-
clui-rns, 490 ; Extinct genera. 491.
Suborder Duplicidextata . . . ■ .491
Family Lagomyid^, 491 ; Lagomys, 491. Family Lepo-
ridje, 492 ; Leims, 492. „
CHAPTER XI
The Order Carxivora . . . 496
Suborder Garni yora Vera . . . . .497
Section tEluroidea, 501. Family FELlD.fi, 502; /'//>-.
502; Cyncelurus, 523; Extinct genera, 523. Family Viver-
riDjE, 525; Cryptoprocta, 525 ; l'ir,rra, 526; .Foss", 527:
Genetta, 528 ; J J rimn„l,,,t, 530 ; Poiana, 531 ; Paradoxurus,
532 ; Arctogalc, 533; Ilrmigalr, 53:1 : Arctictis, 531 ; Nandinia,
534 ; Cynogale, 534; Herpcstes, 535; Heloaa/c, 537; Bilcagah:,
537 ; Cynictis, 537 ; Rhinogalc, 537 : ' 'rossarc/n/s, 537 : Suricata,
538; Galidictis, Gal idea, ami Hemigalidea, 538.; Eupleres,
538 ; Extinct genera, 539. Family PROTELEEDiB, 539 ; /W< ■ 5,
539. Family Hymsxdm, 540 ; ffycena, 5^0. Section Cynoidea,
5 11. Family < 'anid.e, 544 ; Canis, 546 ; Lycaon, 553 ; Iclicyon,
553; Otocyon, 554 ; Extinct genera, 555. tfec&on Arctoidea, 556.
Family I'ksiii.k, 557 ; Crsus, 557 ; Melursus, 560 ; AElurqpus,
560; Extinct genera, 561. Family PROCYONlDfi, 562;
.Elm-ns, 562 : Procyon, 564 : Bassaris, 566 ; Bassaricyon, 566 ;
Nasua, 566; Cercoleptes, 567. Fa, nil,/ M i'stelid.e, 567:
COX/KXTS
Lutra, 567 ; Extinct Otters, 570 ; Latax, 570 ; Mephitis, 572 ;
patus, 574 ; Arctonyx, 571 : Mydaus, 575 ; Meles, 575 ;
Taxidea, 576 ; Mcllivora, 576; Helictls, 578; Ictonyx, 579;
Oalictis, 570 ; Mustela, 579 ; Extinct Mustelines, 590 ; Pcecilo-
gale, 590 ; Lyncodon, 590 ; (thZo, 591.
Suborder PlNNIPBDIA ...... 592
Family OTAXIID2E, 593; Otaria, 593. Family TwCHE-
chid.e, 596; Trkhcchus, 597. Family PHOCiDiE, 600:
ffalichcerus, 601 ; Phoca, 601 ; Monachus, 604 ; Ogmorhinus,
605 ; Lobodon, 605 ; Poxilophoca, 605 ; Ommatophoca, 605 ;
OystopJbora, 605 ; Maerorhinas, 606 ; Extinct seals, 606
Suborder Oreodoxta ..... 606
Hya?nodontidre, 608 ; Proviverridse, 608 ; Arctocyonidre and
Mesonychida?, 609.
CHAPTEE XII
The Order Ixsectivora . . . . .610
Suborder Dermoptera . . . . . .614
Family Galeopithecid^:, 614 ; Galeopithecus, 614.
Suborder Insectivora Vera . . . . .616
Family Tupaiim, 617 ; Tupaia, 617 ; Ptilocercus, 618 ; Ex-
tinct genera, 618. Family Macroscelidid.e, 618 ; Macroscel-
ides, 618 ; Ehyncliocyon, 618. Family Erinaceid.e, 619 ;
Gymnura, 619 ; Erinaceus, 620 ; Extinct genera, 621 ; Family
Soricid^:, 621 ; Sorex, 622 ; Soriculus, 624 ; Xotiosorex, 624 :
Blarina, 624 ; Crossopus, 625 ; Myosorex, 625 ; Crocidura, 626 ;
Diplomesodon, 626; Anurosorex, 626; Chimarrogale, 626; Necto-
gale, 627 ; Fossil Soricidae, 627. Family Talpim:, 628 :
Myogale, 628; Urotrichus, 629; Uropsilus, 629 ; Scalops, 630:
Scapanus, 630 ; Condylura, 630 ; Scajptonyx, 630 ; Talpa, 630 :
Extinct genera, 634. Family Adapisoricid^:, 634. Family
TdTAMOGALiDiE, 634; Polamogale, 635; Geogale, 635. Family
SoLEXODONTiDiE, 635 ; Solcnodon, 636 ; Centctes, 637 ; iZemi-
centetes, 637 ; Ericalus, 638 ; Microgale, 638 ; Oryzorictes, 638 :
Chrysochloris, 639. Extinct types, 640. Bibliography, 640.
CHAPTER XIII
The Order Chiroptera . . . . .641
Suborder Megachiroptera ..... 650
Family Pteropodid^e, 650 ; Epomoplborus, 650 ; Ptcropus,
651 ; Xantharpyia, 652 ; Boneia, 653 ; Cijnoptcrus, 653 :
Harpyia, 653 ; (Jephalotes, 653 ; Pteralopex, 654 ; Notopieris,
654 ; Eonycteris, 654 ; Carponycteris and Melonycteris, 654 :
Xesoaycteris, 655 ; Callinyderis, 655 ; Trygenyetcris, 655.
CONTENTS
Suborder Microchiroi>tera . . 655
Section Vespertilionina, 655. Family Rhinolophuxe,
656; Rhinolophus, 656; Hipposiderus, 657; Anihops, 657;
Uhirumycteris and Tricenops, 658; Ccelops, 658 ; Megaderma,
658. Family Vespertilioniixe, 660 ; Pleeotus, 660 ; Synotus,
661; Otonyeteris, 661: Nyctophilus, 661; Antrozous, 661;
Vesperugo, 661 ; CJialinolobus, 662; Scotqphilus, 662; Nyctice-
jus. 663; Atalapha, 663; Harpyioeephalus, 663; Vespertilio,
663 ; Ci //<■,,,//,/, 66 I : Natalus, 664 ; Miniopterus, 664 ; Thyrop-
tera, 665 ; Myxopoda, 665 ; Fossil Vespertilionidse, 665.
Jom Emballonurina, 666. Family Emballonurid^i, 666 ;
Furipterus and ^morpAocAi7«s,666; Emballonura, 667; Coleura,
667 : Kkyiic/ttiin/ctiTis, 667 ; Siico.ijitrrip; 667 ; Tophozou.% 667 ;
Ijirlitlnrus, 668 ; Xudilio, 668 ; Rhinopoma, 669 ; Chiromeles,
ijtiii : MiJnssus, 670 : Xydinomus, 670 ; Mystacops, 671. Family
PHYLLOSTOMATID.E, 672; Chilonycteris, 672; Mormops, 672;
Lonehorhina, Otopterus, and Dolichophyllum, 673 ; Vampyrus,
etc., 673; Dcsmodus, 677 ; Diphylla, 678.
CHAPTEE XIV
The Order Primates ...... 680
Suborder Lemuroide a . . . . . .682
Family Lemurid^e, 683 ; Indris, 684 ; Propithecus, 684 ;
Avakis, 686; Lemur, 687; Hapalemur, 689; Lepidolemur,
• ;v.i ; I'/iinnjiifrns, 6S9 ; Galago, 690; Nyeticcbus, 691; Loris,
692; Perodicticus, 693. Family Tarsiim:, 694; Tarsias.
694. Family <Jhiromyid,e, 694 ; Chiromys, 6i>[>. Extinct
Lemuroids, 696.
Suborder Axthropoidea . . . . . 699
Fa,, lily Hai'AI.idje, 709: Hapale, 710; Midas, 710. Family
Cebid^:, 711; Mycetes, 711; Pithccia, 712; Uacaria, 712;
Callithrix, 713; Chrysothrix, 714 ; Nyetipifhecus, 714; Ateles,
715; Eriodes, 715; Lagothrix, 716; C'c&ks, 717. Family
Cercopithecid^!, 718 ; Cynocephalus, 719 ; Theropithecus, 722 ;
CynopUhecus, 722; Macacus, 722; Cercoeebus, 723; Cerco-
pithecus, 724 ; Nasalis, 725 ; Semnopithecus, 726 ; Colobus,
727 ; Extinct genera, 727. Family Si.miid.e, 728; Hyldbates,
728 : Simia, 731 ; Gorilla, 734; Anthropopithecus, 736. Family
HoMlNiD.fi, 739 : y/«//fo, 740. Classification of the varieties of
Man, 743.
AN INTRODUCTION"
TO
THE STUDY OF MAMMALS
LIVING AND EXTINCT
CHAPTEE I
INTRODUCTORY REMARKS
Mammalia (French, Mammifkres ; German, Sdugethiere) is the name
invented by Linnaeus (from the Latin mamma), and now commonly
used by zoologists, for one of the five great classes of vertebrated
animals, which, though the best known and undoubtedly the most
important group of the animal kingdom, has never received any
generally accepted vernacular designation in our language. The
unity of structure of the animals composing this class, and their
definite demarcation from other vertebrates, were not recognised
until comparatively modern times, and hence no word was thought
of to designate what zoologists now term a mammal. The nearest
equivalents in common use are "beast" and "quadruped," both of
which, however, cover a different ground, since they are often used
to include the larger four-footed reptiles, and to exclude certain un-
doubted mammals, as Man, Bats, and AVhales.
The limits of the class as now understood by zoologists are
perfectly well defined, and, although certain forms still existing on
the earth (but not those mentioned above as excluded by the popular
idea) are of exceedingly aberrant structure, and exhibit several well-
marked characters connecting them with the lower vertebi'ated
groups, common consent retains them in the class with which the
great proportion of their characters ally them, and hitherto no
traces of any species showing still more divergent or transitional
characters have been discovered. There is thus an interval, not
bridged over by any known forms, between mammals and other
1
INTRODUCTORY
vertebrates ; although recent discoveries have shown evidence of a
more or less marked affinity between the most generalised mammals
and a peculiar group of extinct reptiles known as the Anomodontia
(or Theromora), which are themselves nearly related to the equally
extinct Labyrinthodont amphibians of the Paheozoic and Mesozoic
epochs.
In the gradual order of evolution of living beings, mammals,
taken altogether, are certainly the highest in organisation, as, with
the possible exception of birds, they were the last to appear on
the earth's surface. But, as in speaking of all other large and
greatly differentiated groups, this expression must not be understood
in too limited a sense. The tendency to gradual perfection for
their particular station in life, which all groups manifest, leads
to various lines of specialisation, or divergence from the common
or general type, which may or may not take the direction of
elevation. A too complex and sensitive condition of organisation
may in some circumstances of life be disadvantageous, and modifi-
cation may then take place in a retrograde direction. Thus in
mammals, as in other classes, there are low as well as high forms,
but by any tests that can be applied — especially those based on
the state of development of the central nervous system — it will
be seen that the average exceeds that of any other class ; that
the class contains many species far excelling those of any other
in perfection of structure, and especially one form which is un-
questionably the culminating point yet arrived at amongst organised
beings.
With regard to the time of the first appearance of mammals
upon the earth, the geological record is provokingly imperfect. At
the commencement of the Tertiary period they were abundant, and
already modified into most of the leading types at present existing.
It was at one time thought that they first came into being at this
date, but the discovery of more or less fragmentary remains of
numerous and generally small species has revealed the existence of
some forms of the class at various periods throughout almost the
whole of the age of the deposition of the Secondary or Mesozoic
rocks. This subject will be reverted to later on.
It hardly need be said that mammals are vertebrated animals,
and possess all the characteristics common to the members of that
division of the animal kingdom. They are separated from the
TcMhyopsida (fishes and amphibians), and agree with the Sawopsida
(reptiles and birds) in the possession during their development of
an amnion and allantois, and in never having external branchite or
gills. They differ from reptiles and resemble birds in being warm-
blooded, and having a heart with four cavities and a complete
double circulation. They differ from both birds and reptiles in the
red corpuscles of the blood being non-nucleated and, with very few
INTRODUCTORY
exceptions, circular in outline ; in the lungs being freely suspended
in a thoracic cavity, separated from the abdomen by a complete
muscular partition — the diaphragm — which is the principal agent
in inflating the lungs in respiration ; in having but one aortic arch,
which curves over the left bronchus ; in the skin being more or less
clothed with hair ; in the greater perfection of the commissural
system of the cerebral hemispheres, which has either a complete
corpus callosum, or an incomplete one associated with a very
large anterior commissure ; in having no syrinx or inferior vocal
organ, but a complete larynx at the upper end of the trachea ;
in having a mandible of which each ramus (except in very early
developmental conditions) consists of a single bone on each side,
articulating to the squamosal without the intervention of a quad-
rate bone ; in having a pair of laterally placed occipital condyles
instead of one median one ; and in the very obvious character of
the female being provided with mammary glands, by the secretion
of which the young (usually produced alive, although in the lowest
forms by means of externally hatched eggs) are nourished for some
time after birth.
In common with all vertebrated animals, mammals never have
more than two pairs of limbs ; as the larger number live ordinarily
on the surface of the earth, in the great majority of the class
both pairs are well-developed and functional, and adapted for terres-
trial progression. Mammals are, however, by no means limited to
this situation. Thus some species spend the greater part of their
lives beneath the surface, their fore limbs being specially modified
for burrowing ; others, again, are habitually arboreal, their limbs
being fitted for climbing or hanging to boughs of trees ; some are
as aerial as birds, the fore limbs being developed into wings of a
special character ; while in others which are as aquatic as fishes,
the limbs assume the form of fins or paddles. In many of the
latter the hinder extremities are either completely suppressed, or
present only in a rudimentary state. In no known mammal are
the fore limbs absent.
The hinder extremity of the axis of the body is usually prolonged
into a tail, which may be a mere pendent appendage, or may be
modified to perform various functions, as grasping boughs in
climbing, or even gathering food, in the case of the prehensile-
tailed Monkeys and Opossums, swimming in the Cetacea, and acting
as a flap to drive away troublesome insects from the skin in the
Ungulata.
The state of development of the young at the time of birth
varies greatly in the different groups. Thus among the Marsupials
where there is no connection during infra-uterine life between the
circulatory systems of the parent and the fcetus, the young are
born in an exceedingly imperfectly developed condition. For their
INTRODUCTORY
protection the mother, in a large number of cases, has a special
pouch enclosing the mammae, into which the young are transferred
at birth, and in which they remain till they are well developed.
Among the higher, or Placental types, however, where a connection
exists between the maternal and foetal circulations previous to birth,
the young are always born in a much more highly developed state
than among the Marsupials, although we meet with great variations
in this respect. In those forms which habitually live in holes, like
many Rodents, the young are always very helpless at birth ; and
the same is also true of many of the Carnivora, which are well able
to defend their young from attack. In the great order of
Ungulate, or Hoofed Mammals, where in the majority of cases
defence from foes depends upon fleetness of foot, or upon huge
corporeal bulk, the young are born in a very highly developed
condition, and are able almost at once to run by the side of the
parent. This state of relative maturity at birth reaches its highest
development in the Cetacea, where it is evidently, associated with
the peculiar conditions under which these animals pass their
existence. In the Primates, however, we again find the young
produced in a more or less helpless condition, and requiring a long-
period before they attain their full development, this being more
especially the case with those higher forms which approximate in
structure to man.
In point of size mammals vary to a greater extent than the
existing members of any one class of animals, and include the
largest living inhabitants of the earth. The extremes of size are
marked on the one hand by the whale known as Sibbald's Rorqual,
which attains a length of eighty feet and a weight of nearly as many
tons, and on the other by the Pigmy-Shrew and the minute Harvest-
mouse, which can climb a stem of wheat.
Of all the living creatures inhabiting our globe, mammals are by
far the most important in their economic uses, since, in addition to
being the only animals capable of labour for human benefit, the}'
furnish the greater portion of the animal food of many races of man,
and likewise a large amount of their clothing. In these respects
the Ungulates hold the first place.
As regards employment for labour, with the exception of the
Dogs used for sleighing by the Esquimaux, and those which among
some European nations draw light carts, all the mammals in general
use are Ungulates. Of the first importance are the Horses and
Asses, which are employed as beasts of draught or burden over
nearly the whole globe. Among many nations, however, cattle, as
represented by the true Oxen, the Buftalos, and the Yaks of Tibet,
occupy a still more important position, while in the highlands of
Tibet Sheep are largely used for carrying burdens. In other regions,
again, the place of the Horse and the Ass is taken by the Camels,
INTRODUCTORY 5
which are peculiarly fitted for traversing parched and arid deserts,
while in the Andes Ave find the Llamas serving the same office.
In Lapland and other parts of the northern regions the Reindeer is
the main agent employed in draught. Lastly, we must not omit
to mention the Indian Elephant, •which, from its vast strength, is so
useful in transport through the wilder parts of its native country.
As regards food, we again find the Ungulates, and more
especially the Artiodactyle division, taking the foremost place ; and
in this connection Ave haA r e only to mention, among animals .kept
in a domestic condition, SAvine, Cattle, Sheep, and Goats — the three
latter affording not only their flesh, but also milk and its resulting
cheese and butter. To many races, however, Mares and Camels are
the chief milk producers, Avhile the Laps make use of the milk of
the Reindeer. The Rodents, as represented by Hares and Rabbits,
occupy a minor position as furnishers of food.
In relation to clothing, the Ungulates are likeAvise of paramount
importance, as exemplified by the avooI of the Sheep, Avhich is so
valuable on account of its peculiar property of felting. Furs,
hoAvever, are mostly yielded by mammals of other orders, among
Avhich the Fur-seals are perhaps the most important at the present
day. Many other Carnivores yield valuable furs, among Avhich may
be mentioned Bears, Foxes, Racoons, Skunks, Minks, Otters, and
Ermines. Of less importance are certain Rodents, such as the
Squirrels, Rabbits, Hares, etc., Avhile the hair of the Beaver Avas
formerly much sought after for the manufacture of hats. Returning
to the Ungulates, Ave may notice the importance of horse-hair, the
employment of camel's hair for brushes, and the many uses of the
bristles of the pig. Some of the Monkeys yield fur Avhich has
been extensively used. Leather, again, is almost exclusively
supplied by mammals, and mainly by the Ungulates.
Three other important products, namely horn, buck's -horn, and
ivory, are likeAvise obtained solely from the same great order.
Horn, as we shall notice in the sequel, is the sheath covering the
bony horn-cores of the Oxen, A\-hile buck's-horn is the commercial
term applied to the antlers of the Deer, which are largely used for
knife-handles and other purposes. True ivory is the product of
the tAvo species of Elephant ; but other kinds of ivory are obtained
from the teeth of the Sperm Whale and the tusks of the Walrus and
Hippopotamus, the latter kind having been extensiA^ely employed
some years ago for artificial teeth. For many purposes the place of
ivory is taken by bone, this being mostly obtained from Ungulates.
The bones of Camels are of an especially firm texture and good
colour, and are largely employed in India for inlaying. Other
important uses of bones are in the form of bone-dust as manure,
and also as a source of phosphoric acid. The horns of the African
Rhinoceros and the hide of the Hippopotamus are occasionally
INTRODUCTORY
manufactured into small canes or whips. Horns and hoofs are also
largely employed in the manufacture of glue.
Formerly the so-called whalebone, or more properly baleen,
was much used, especially to form the ribs of umbrellas and in
stiffening ladies' apparel, but the gradual destruction of the Eight
Whales, its only source of supply, has largely restricted its use of
late years.
The Cetacea are also of great economical importance from the
abundance of oil yielded by the thick layer of blubber underlying
the skin. Large quantities of valuable oil are also furnished by
the Walrus and the Seals. Spermaceti, which was at one time
extensively used in the manufacture of candles, is obtained from ;i
large cavity in the head of the Sperm Whale or Cachalot, and also
from the Hyperoodon or Bottle-nosed Whale.
The nature of ambergris, a peculiar substance found floating on
the surface of the sea and employed in perfumery, was long a
matter of controversy ; but it appears to be an intestinal concretion
of the Sperm Whale. Other substances of more importance to the
perfumer are musk, the product of the Musk-Deer of the Himalaya,
and civet, which is obtained from the so-called Civet Cat and other
allied Carnivores. A secretion of the Beaver has also been used in
perfumery and in medicine.
CHAPTER II
GENERAL ANATOMICAL CHARACTERS
I. TEGUMENTARY STRUCTURES
Hair. — The external surface of the greater number of members of
the class is thickly clothed with a peculiarly modified form of
epidermis, commonly called hair. This consists of hard, elongated,
slender, cylindrical or tapering, filiform, unbranched masses of
epidermic material, growing from a short papilla sunk at the
bottom of a follicle in the derm or true skin. Such hairs upon
different parts of the same animal, or upon different animals, assume
various forms, and are of various sizes and degrees of rigidity, — as
seen in the delicate soft velvety fur of the Mole, the stiff* bristles
of the Pig, and the spines of the Hedgehog and Porcupine,
all modifications of the same structures. Each hair is composed
usually of a cellular pithy internal portion, containing much air,
and a denser or more horny cortical part. In some animals, as
Deer, the substance of the hair is almost entirely composed of the
medullary or cellular substance, and it is consequently very easily
broken ; in others the horny part prevails almost exclusively, as in
the bristles of the Wild Boar. In the Three-toed Sloth (Bradypus)
the hairs have a central horny axis and a pithy exterior. Though
generally nearly smooth, or but slightly scaly, the surface of some
hairs is strongly imbricated, notably so in some Bats ; while in the
Two-toed Sloth (Cholcepus) the hairs are longitudinally grooved or
fluted. Though usually more or less cylindrical or circular in
section, hairs are often elliptical or flattened, as in the curly-haired
races of men, the terminal portion of the hair of Moles and Shrews,
and conspicuously in the spines of the Rodents Xerus and Platacantho-
mys. Hair having a property of mutual cohesion or "felting,"
which depends upon a roughened scaly surface and a tendency to
curl, as in domestic Sheep (in which animal this property has been
especially cultivated by selective breeding), is called " wool."
8 GENERAL ANATOMICAL CHARACTERS
In a large number of mammals hairs of one kind only are
scattered pretty evenly over the surface ; but in many there are two
kinds, one longer, stiffer, and alone appearing on the surface, and
the other shorter, finer, and softer, constituting the under fur,
analogous to the down of birds. This under fur, or pashm as it is
called by the natives of Kashmir, is especially abundant in the
mammals inhabiting the cold plateau of Tibet and the adjacent
regions. In many cases hairs of a different character from those of
the general surface grow in special regions, forming ridges or tufts
on the median dorsal or ventral surface or elsewhere. The tail is
very often completed in this way by variously disposed elongated
hairs. The margins of the eyelids are almost always furnished with
a special row of stifhsh hairs, called cilia or eyelashes ; and in most
mammals specially modified hairs, constituting the vibrissa' or
whiskers, and endowed, through the abundant nerve supply of their
basal papillae, with special tactile powers, grow from the lips and
cheeks. In some mammals the hairy covering is partial and limited
to particular regions ; in others, as the Hippopotamus and the Sirenia,
though scattered over the whole surface, it is extremely short and
scanty ; but in none is it reduced to so great an extent as in the
Cetacea, in which it is limited to a few small bristles confined to the
neighbourhood of the lips and nostrils, and often only present in
the young or even foetal condition.
Some kinds of hairs, as those of the mane and tail of the Horse,
appear to persist throughout the life-time of the animal ; but more
generally, as in the case of the body hair of the same animal, they
are shed and renewed periodically, generally annually. Many
mammals have a longer hairy coat in winter, which is shed as
summer comes on ; and some few, which inhabit countries covered
in winter with snow, as the Arctic Fox, Variable Hare, and Ermine,
undergo a complete change of colour in the two seasons, being-
white in winter, and gray or brown in summer. The several species
of Cape Mole (Chrysochloris), the Desmans or Water Moles (Myogale),
and Potarnogale velox, are remarkable as being the only mammals
whose hair reflects those iridescent tints so common in the feathers
of tropical birds.
The principal and most obvious purpose of the hairy covering is
to protect the skin against external influences, especially cold and
damp. Its function in the hairless Cetacea is supplied by the
specially modified and thickened layer of adipose tissue beneath the
skin, called "blubber."
Colour. — From the consideration of hair we are easily led to
that of colour. As a general rule, bright and primary colours are
absent in the class ; but among the Baboons we find brilliant patches
of scarlet or blue on some of the bare portions of the body, and one
of the South American Monkeys (Brachyums) has its whole face of
TEGUMEA'TARY STRUCTURES
a bright crimson. The most general colours are various shades of
gray, brown, and tawny, with a frequent tendency to whiteness of
the ventral surface of the body; but among the Squirrels, and more
especially those provided with a parachute for flying, we find brilliant
russets, passing into orange and red. Dark brown or black is also
not very uncommon, as in the Bears and the Sable Antelope of
South Africa. Entirely white mammals are rare, and mostly
characteristic of the polar regions, or of countries having a long
and snowy winter. An entirely white Bat (Diclidurus alius) occurs,
however, in South America. In the large majority of mammals
that exhibit a varied coloration, the upper and most exposed parts
of the surface present the richest and darkest colours, the under
parts being pale or often quite white. The Katels, Gluttons, jElurus,
Hamsters, and some others are exceptions to this rule. A large
number of mammals having a ground colour of gray, tawny, or dun
are marked by stripes or spots, which are generally of a darker hue
than the ground colour, as in many Carnivora, but more rarely are
lighter, as in the Fallow and Axis Deer and several species of Ante-
lope. These stripes very generally run transversely to the axis of the
body, as in the Tasmanian Thylacine, the Tiger, and the Zebra ; but
they may be longitudinal, as in several of the Civet family. There has
been considerable discussion as to whether the striped or the spotted
is the more primitive type of coloration ; but no very conclusive
arguments have been brought forward in favour of either view. It
is, however, manifest that in several groups of mammals there is a
tendency to lose the spots, and more rarely the stripes, and to
assume a uniform colour. Thus the young of nearly all the species
of Deer are spotted, whereas the adults of only the Fallow and
Axis Deer are so marked. The same is true of most of the Pigs ;
and the young of the Malayan and American Tapirs are marked
by light- coloured stripes and spots on a dark ground. In like
manner the young of the Lion and the Puma exhibit distinct spots
which disappear with advancing age. In most of our domestic
horses of various shades of bay and brown we may detect " dappling "
on the under hair when the outer coat has been removed, which
is not apparent on the surface of the latter. Many varieties of
the Ass and the Horse also exhibit a tendency to the presence of
stripes on the legs, which would seem to indicate a descent from a
striped Zebra-like type.
A peculiar feature, which is, however, common to many other
groups of animals, is the tendency to what is known as melanism,
or the production of black or dark individuals or races of particular
species, due to an excess of pigment in the skin and hair. Thus Ave
may have black Leopards and Jaguars, black Wolves, and black
Rabbits.
The opposite to melanism, and of more frequent occurrence, is
io GENERAL ANATOMICAL CHARACTERS
albinism — a condition in which the pigment or colouring matter
usually present in the tissues constituting the external coverings of
the body, and which gives them their characteristic hue, is absent.
When it occurs the hair is of an opaque white, the claws, hoofs, etc., of
a pale horn-colour, and the skin and eyes pink, in consequence of the
colour of the blood which circulates through them being no longer
concealed by the stronger hues of the pigments. An animal in this
condition is called an albino. In complete albinism there is a total
absence of pigment throughout the system. This condition occurs
occasionally as an individual peculiarity among wild animals of
many kinds ; but it has never been perpetuated among them in dis-
tinct races or species. The disadvantage of absence of pigment
in the eye, causing a certain amount of intolerance of light, is
probably sufficient to account for this. Several races of true
albinos, as White Ferrets, Rabbits, Rats, and Mice, have, however,
been established under the protection of man, and in them this ab-
normal condition is propagated from generation to generation.
Partial albinism — a condition in which the absence of pigment
is limited to portions of the surface, or, at all events, does not extend
to the eyes — is much more common as an individual variation both
in domestic and in wild animals. It is possible that the artificial
conditions incident to domestication increase the tendency to its
occurrence ; but, whether this be so or not, it certainly becomes
perpetuated more frequently among domesticated than among wild
animals. This may be accounted for partly by its proving of no
disadvantage to them, and partly by the frequent selection by man
of animals of such colour in preference to others. The result is that
there is no completely domestic animal of which white races do not
exist. On the other hand, to most wild animals even partial
albinism seems to be a disadvantage in the struggle for existence,
since, except in the case of species inhabiting lands continually
covered with snow, it renders them more conspicuous objects both
to their enemies and their prey, and hence it is rarely perpetuated.
In northern regions, however, a large proportion of species are
regularly and normally of a white colour, either, as the Polar Bear,
all the year through, or, as the Ermine or Stoat, Arctic Fox, and
Alpine Hare, during the winter season. The coloration in these
cases is obviously protective, as it is also to a great extent in many
other instances throughout the class.
Among conspicuously coloured mammals, it has been observed
that the vertical black and tawny stripes of the Tiger harmonise so
well with the brown and green grasses of its native jungle as to
render the animal almost invisible when lying among them ; while
the dappled hide of the Giraffe is said to agree equally well
with the chequered splashes of light and shade in the clumps of tall
mimosas among which it feeds. The uniformly tawny hue of the
TEGUMENTARY STRUCTURES n
Lion accords well with the prevailing tint of its native desert ; and
any one who has seen an Elephant or Buffalo in the dee}) shades of
an Indian forest will realise how perfectly adapted is their dull,
slaty colour to concealment in such a spot. The dun colour of the
Wild Ass of India is equally well suited to the sandy deserts of
Kutch ; it is also stated that the brilliant stripes of the Zebras of
Africa are arranged in such proportion as exactly to match the pale
tint which arid ground possesses when seen by moonlight. 1 The
most remarkable instance of protective coloration is, however, to be
found in the Sloths of South America, in which the coarse gray
hairs so closely resemble a mass of lichenous growth that it is
almost impossible to distinguish these animals when at rest from
the gnarled and lichen-clad boughs from which they suspend them-
selves. This resemblance is increased by the fact that the hairs
actually develop a growth of lichens upon themselves. That the
sombre coloration of these animals has been produced to harmonise
with their present surroundings seems to be evident by the circum-
stance that when the long hair is plucked off the under fur is seen
to present a bold alternation of black and yellow stripes, which
may probably be regarded as the original primitive coloration of
this group.
Scales, etc. — True scales, or flat imbricated plates of horny
material, covering the greater part of the body, so frequently
occurring in reptiles, are found only in one family of mammals, the
Manidxe or Pangolins ; but these are also associated with hairs
growing from the intervals between the scales, or on the parts of
the skin not covered by them. Similarly, imbricated epidermic
productions form the covering of the under surface of the tail of
the flying Eodents of the genus Anomalurus ; and flat scutes, with
the edges in apposition, and not overlaid, clothe both surfaces of
the tail of the Beaver, Rats, and others of the same order, and also
of some Insectivores and Marsupials. The Armadillos alone have
an ossified exoskeleton, composed of plates of true bony tissue,
developed in the derm or corium, and covered with scutes of horny
epidermis. Other epidermic appendages are the horns of Ruminants
and Rhinoceroses, — the former being elongated, tapering, hollow
caps of hardened epidermis of fibrillated structure, fitting on and
growing from conical projections of the frontal bone, and always
arranged in pairs, while the latter are of similar structure, but
solid and without any internal bony support, and (in all existing
species) situated in the median line. Callosities, or bare patches
covered with hardened and thickened epidermis, are found covering
the pads under the soles of the feet and undersurfaces of the
toes of nearly all mammals, upon the ischial tuberosities of many
Apes, the sternum of Camels, on the inner side of the limbs of the
1 Galton's South Africa, p. 187.
12 GENERAL ANATOMICAL CHARACTERS
Equidce, the grasping under surface of the tail of the prehensile-tailed
Monkeys, etc. The greater part of the skin of both species of
one-horned Asiatic Ehinoceros is immensely thickened and stiffened
by increase of the tissue both of the derm and epiderm, con-
stituting the well-known jointed "armour-plated" hide of those
animals.
Nails, Claws, and Hoofs. — With very few exceptions, the terminal
extremities of the digits of both limbs are more or less protected or
armed by epidermic plates or sheaths, constituting the various forms
of nails, claws, or hoofs. These are wanting in the Cetacea alone.
A perforated spur, with a special secreting gland in connection with
it, is found attached to the hind leg of the males of the three genera
of Monotremata, Ornithorhynehus, Proechidna, and Echidna.
Odour - secreting Glands. — Besides the universally distributed
sebaceous glands connected Avith the pilose system, most mammals
have special glands situated in modified portions of the integument,
often involuted to form a shallow recess or a deep sac with a narrow
opening, situated in various parts of the surface of the body, and
secreting odorous substances, by the aid of which individuals
appear to recognise one another, and probably affording the princi-
pal means by which wild animals are able to become aware of
the presence of other members of the species, even at great dis-
tances. Although the commencement of the modifications of
portions of the external covering for the formation of special
secretions may be at present difficult to understand, the principle
of natural selection will readily explain how such organs become
fixed and gradually increase in development in any species, especi-
ally as there would probably be a corresponding modification and
increased sensibility of the olfactory organs. Such individuals as
by the intensity and peculiarity of their scent had greater power of
attracting the opposite sex would certainly be those most likely to
leave descendants to inherit and in their turn propagate the modi-
fication.
To this group of structures belong the suborbital gland or
" crumen " of Antelopes and Deer, the frontal gland of the Muntjak
and of Bats of the genus Hipposiderus, the submental gland of the
Chevrotains and of Taphozous and some other Bats, the post-auditory
follicle of the Chamois, the temporal gland of the Elephant, the
lateral glands of the Musk-Shrew, the dorsal gland of the Peccary,
the inguinal glands of Antelopes, the preputial glands of the Musk-
Deer and Beaver (already alluded to in connection with the use
made of their powerfully odorous secretion in medicine and per-
fumery) and also of the Swine and Hare, the anal glands of Carni-
vora, the perineal gland of the Civet (also of commercial value), the
caudal glands of the Fox and Goat, the gland on the humeral
membrane of Bats of the genus Saccopteryx, the post-digital gland of
DENTAL SYSTEM 13
the Rhinoceros, the inter-digital glands of the Sheep and many
Ruminants, and numerous others. In some of these cases the
glands are peculiar to, or more largely developed in, the male ; in
others they are found equally developed in both sexes.
II. DENTAL SYSTEM
The dental system of mammals may be considered rather
more in detail than space permits for some other portions of their
structure, not only on account of the important part it plays in the
economy of the animals of this class, out also for its interest to
zoologists as an aid in the classification and identification of species.
Owing to the imperishable nature of their tissues, teeth are
preserved for an indefinite time, and in the case of extinct
species frequently offer the only indications available from which
to derive an idea of the characters, affinities, and habits of the
animals to which they once belonged. Hence even their smallest
modifications have received great attention from comparative
anatomists, and they have formed the subject of many special
monographs. 1
Teeth are present in nearly all mammals, and are applied
to various purposes. They are, however, mainly subservient
to the function of alimentation, being used either in procuring
food, by seizing and killing living prey or gathering and biting
off portions of vegetable material, and more indirectly in tearing
or cutting through the hard protective coverings of food sub-
stances, as the husks and shells of nuts, or in pounding, crushing,
or otherwise mechanically dividing the solid materials before
swallowing, so as to prepare them for digestion in the stomach.
Certain teeth are also in many animals most efficient weapons of
offence and defence, and for this purpose alone, quite irrespective
of subserviency to the digestive process, are they developed in the
male sex of many herbivorous animals, in the females of which
they are absent or rudimentary.
Teeth belong essentially to the tegumentary or dermal system
of organs, and, as is well seen in the lower vertebrates, pass by
almost insensible gradations into the hardened spines and scutes
formed upon the integument covering the outer surface of the
body ; but in mammals they are more specialised in structure and
limited in locality. In this class they are developed only in the
1 L. F. E. Rousseau, Anatomic comjiaree du Systeme dentaire chez V Homme el
chez les principaux Animaux, 2d ed., 1839 ; F. Cuvier, Des Dents des Mammiferes
considere'es comme caracteres zoologiques, 1822-25 ; R. Owen, Odontograimy,
1840-45 ; C. G. Giebel, OdontograpMe, 1855 ; C. S. Tomes, Manual of Dental
Anatomy, Human and Comparative, 3d ed., 1889.
i 4 GENERAL ANATOMICAL CHARACTERS
giims or fibro-mucous membrane covering the alveolar borders of
the upper and lower jaws, or, in other words, the premaxillary
and maxillary bones and the mandible. In the process of develop-
ment, for the purpose of giving them that support which is needful
for the performance of their functions, they almost always become
implanted in the bone, — the osseous tissue growing up and mould-
ing itself around the lengthening root of the tooth, so that
ultimately they become apparently parts of the skeleton. In no
mammal, however, does ankylosis or bony union between the
tooth and jaw normally take place, as in many fishes and reptiles,
— a vascular layer of connective tissue, the alveolo-dental mem-
brane, always intervening. 1 The presence of two or more roots,
frequently met with in the cheek-teeth of mammals, implanted in
corresponding distinct sockets of the jaw, is now peculiar to animals
of this class. 2
Structure. — The greater number of mammalian teeth when fully
formed are not simple and homogeneous in structure, but are com-
posed of several distinct tissues, which are enumerated below.
The pulp, a soft substance, consisting of a very delicate
gelatinous connective tissue, in which numerous cells are imbedded,
and abundantly supplied with blood-vessels and nerves, constitutes
the central axis of all the basal part- of the tooth, and affords the
means by which the vitality of the whole is preserved. The
nerves which pass into the pulp and endow the tooth with
sensibility are branches of the fifth pair of cranial nerves. The
pulp occupies a larger relative space, and performs a more important
purpose, in the young growing tooth than afterwards, as by the
calcification and conversion of its outer layers the principal hard
constituent of the tooth, the dentine, is formed. In teeth which
have ceased to grow the pulp occupies a comparatively small space,
which in the dried tooth is called the pulp-cavity. This communi-
cates with the external surface of the tooth by a small aperture at
the apex of the root, through which the branches of the blood-
vessels and nerves, by which the tooth receives its nutrition and
sensitiveness, pass in to be distributed in the pulp. In growing
teeth the pulp-cavity is widely open, while in advanced age it often
becomes obliterated, and the pulp itself entirely converted into
bone-like material.
The dentine or ivory forms the principal constituent of the
greater number of teeth. When developed in its most character-
istic form, it is a very hard but elastic substance, white, with a
yellowish tinge, and slightly translucent. It consists of an organic
1 The lower incisors of some species of Shrews are, however, said to become
aukyloaed to the jaw in adult age.
- The teeth of the extinct Dinosaurian reptile Triceratqps have two distinct
roots, placed transversely to the axis of the jaws.
DENTAL SYSTEM 15
matrix, something like, but not identical with, that of bone, richly
impregnated with calcareous salts (chiefly calcium phosphate), these
constituting in a fresh human tooth 72 per cent of its weight.
When subjected to microscopical examination it is seen to be every-
where permeated by nearly parallel branching tubes which run,
in a slightly curving or wavy manner, in a general direction from
the centre towards the free surface of the tooth. These tubes com-
municate by open mouths with the pulp-cavity, and usually ter-
minate near the periphery of the dentine by closed ends or loops,
though in Marsupials and certain other mammals they penetrate
into the enamel. They are occupied in the living tooth by soft
gelatinous fibrils connected with the cells of the pulp. A variety
of dentine, permeated by canals containing blood-vessels, met with
commonly in fishes and in some few mammals, as the Megatherium, is
called vaso-dentine. Other modifications of this tissue occasionally
met with are called osteo-dentine and secondary dentine, — the
latter being a dentine of irregular structure which often fills up the
pulp-cavity of old animals.
The enamel constitutes a thin investing layer, complete or
partial, of the outer or exposed and working surface of the dentine
of the crown of the teeth of most mammals. This is the hardest
tissue met with in the animal body, containing from 95 to 97 per
cent of mineral substances (chiefly calcium phosphate and some
carbonate, with traces of fluoride). Its ultimate structure consists
of prismatic fibres, placed generally with their long axes at right
angles to the free surface of the tooth. Enamel is easily distin-
guished from dentine with the naked eye by its clear, bluish-white,
translucent appearance.
The cement or crusta petrosa is always the most externally placed
of the hard tissues of which teeth are composed, as will be under-
stood when the mode of development of these organs is considered.
It is often only found as a thin layer upon the surface of the root ;
but sometimes, as in the complex-crowned molar teeth of the Horse
and Elephant, it is a structure which plays a very important part,
covering and filling in the interstices between the folds of the
enamel. In appearance, histological structure, and chemical com-
position it is closely allied to osseous tissue, containing lacuna? and
canaliculi, though only when it is of considerable thickness are
Haversian canals present in it.
Development. — The two principal constituents of the teeth, the
dentine and the enamel, are developed from the two layers of the
mucous membrane of the jaw — the dentine from the deeper or vas-
cular, the enamel from the superficial or epithelial layer. The latter
dips down into the substance of the gum, and forms the enamel-organ
or germ, the first rudiment of the future tooth, which is constantly
present even in those animals in which the enamel is not found as a
16 GENERAL ANATOMICAL CHARACTERS
constituent of the perfectly-formed tooth. Below the mass of epi-
thelial cells thus embedded in the substance of the gum, and remaining
connected by a narrow neck of similar structure with the epithelium
of the surface, a portion of the vascular areolar tissue becomes
gradually separated and defined from that which surrounds it, and
assumes a distinct form, which is that of the crown of the future
tooth, — a single cone in the case of simple teeth, or with two or
more eminences in the complex forms. This is called the dental
papilla or dentine germ, and by the gradual conversion of its tissue
into dentine the bidk of the future tooth is formed, the uncalcified
central portion remaining as the pulp. The conversion of the
papilla into hard tissue commences at the outer surface of the apex,
and gradually proceeds downwards and inwards, so that the form of
the papilla exactly determines the form of the future dentine, and
no alteration either in shape or size of this portion of the tooth,
when once calcified, can take place by addition to its outer surface.
In the meanwhile, calcification of a portion of the cells of the enamel-
organ, which adapts itself like a cap round the top of the dentinal
papilla, and has assumed a somewhat complex structure, results in
the formation of the enamel -coating of the crown of the tooth.
While these changes are taking place the tissues immediately sur-
rounding the tooth-germ become condensed and differentiated into
a capsule, which appears to grow up from the base of the dental
papilla, and encloses both this and the enamel-germ, constituting
the follicle or tooth-sac. By the ossification of the inner layer of
this follicle the cement is formed. This substance, therefore, unlike
the dentine, increases from within outwards, and its growth may
accordingly be the cause of considerable modification of form and
enlargement, especially of the roots, of certain teeth, as those of
Seals and some Cetacea. The delicate homogeneous layer coating the
enamel surface of newly-formed teeth, in which cement is not found
in the adult state, and known as Xasmyth's membrane, is considered
by Tomes as probably a film of this substance, too thin to exhibit
its characteristic structure, though by others it is believed to be
derived from the external layer of the enamel-organ. The homology
of the teeth Avith the dermal appendages, hairs, scales, and claws,
has already been alluded to, and it will now be seen that in both cases
two of the primary embryonic layers are concerned in their develop-
ment — the mesoblast and epiblast — although in very different pro-
portions respectively. Thus in the hair or nail the part derived from
the epiblast forms the principal bulk of the organ, the mesoblast
only constituting the papilla or matrix. But in the tooth the epi-
blastic portion is limited to the enamel, and is always of relatively
small bulk and often absent, while the dentine (the principal con-
stituent of the tooth) and the cement are formed from the mesoblast.
"When more than one set of teeth occur in mammals, those of
DENTAL SYSTEM 17
the second set are developed in a precisely similar manner to the
first, bnt the enamel-germ, instead of being derived directly from an
independent part of the oral epithelium, is formed from a budding
out of the neck of the germ of the tooth succeeded. In the case of
the true molars, which have no predecessors, the germ of the first
has an independent origin, but that of the others is derived from the
neck of the germ of the tooth preceding it in the series. The
foundations of the permanent teeth are thus laid as it were almost
simultaneously with those of their predecessors, although they
remain in many cases for years before they are developed into
functional activity.
Although the commencement of their formation takes place
at an early period of embryonic life, teeth are in nearly all mam-
mals still concealed beneath the gum at the time of birth. The
period of eruption, or " cutting " of the teeth as it is called, that is,
their piercing through and rising above the surface of the mucous
membrane, varies much in different species. In some, as Seals, the
whole series of teeth appears almost simultaneously; but more often
there are considerable intervals between the appearance of the
individual teeth, the front ones usually coming into place first, and
those at the back of the mouth at a later period.
Farms <>f Teeth. — The simplest form of tooth may be exemplified
on a large scale by the tusk of the Elephant (Fig. 1, I.) It is a
hard mass almost entirely composed of dentine, of a conical shape
at first, but during growth becoming more and more cylindrical or
uniform in width. The enamel -covering, present on the apex in
its earliest condition, soon disappears, but a thin layer of cement
covers the circumference of the tooth throughout life. In section
it will be seen that the basal portion is hollow, and contains a large
conical pulp, as broad at the base as the tooth itself, and deeply
imbedded in the bottom of a recess, or socket, in the maxillary
bone. This pulp continues to grow during the lifetime of the
animal, and at the same time is converted at its surface into dentine.
The tooth therefore continually elongates, but the use to which the
animal subjects it in its natural state causes the apex to wear away,
at a rate generally proportionate to the growth at the base, other-
wise it would become of inconvenient length and weight. Such
teeth of indefinite growth are said to be "rootless," or to have
"persistent pulps."
One of the corresponding front teeth of man (Fig. 2, II. and III.)
may be taken as an example of a very different condition. After its
crown is fully formed by calcification of the germ, the pulp, though
continuing to elongate, begins to contract in diameter ; a neck or
slight constriction is formed ; and the remainder of the pulp is con-
verted into the root (often, but incorrectly, called "fang"), a taper-
ing conical process imbedded in the alveolar cavity of the bone, and
2
i8
GENERAL ANATOMICAL CHARACTERS
having at its extremity a minute perforation, through which the
vessels and nerves required to maintain the vitality of the tooth enter
the pulp -cavity, which is
very different from the
widely open cavity at
the base of the growing
tooth. When the crown
of the tooth is broad and
complex in character, in-
stead of having a single root,
it may be supported by
two or more roots, each of
which is implanted in a
distinct alveolar recess or
socket, and to the apex of
which a branch of the com-
mon pulp-cavity is continued
(Fig. 1, IV.) Such teeth are
called "rooted teeth." When
they have once attained their
position in the jaw, with the
neck a little way above the
level of the free margin of
the alveolus, and embraced
by the gum or tough fibro-
vascular membrane covering
the alveolar border, and hav-
ing the root fully formed,
they can never increase in
length or alter their posi-
tion ; if they appear to do
so in old age, it being only
in consequence of absorption
and retrocession of the sur-
alveolar
rounding
margins.
Fio. 1. — Diagrammatic Sections of various forma of
Teeth. I. Incisor or tusk of Elephant, with pulp-
cavity persistently open at base. II. Human incisor
during development, with root imperfectly formed,
andpulp-cavitywidelyopenatba.se. III. Completely
formed human incisor, with pulp-cavity contracted to Jf ? as often happens, their
a small aperture at the end of the root. IV. Human c „____, -C^ ™r.o
.;, , , , . t ,. ,, , r surface wears away in mas-
molar, with broad crown and two roots. \. Molar of D »" ■"*»'« " _ J
the Ox, with the enamel covering the crown deeply tication, it is never renewed.
folded, and the depressions tilled up with cement. The TJjo ODen CavitV at the base
surface is worn by use ; otherwise the enamel coating r , . . r j.i j l J
would be continuous at the top of the ridges, in all of the imperfectly developed
the figures the enamel is black, the pulp white, the tooth (Fig. 1, II.) Causes it
dentine represented by horizontal lines, and the cement j._ resemble the Dersistent
by dots. r i i
condition of the rootless
tooth. The latter is therefore a more primitive condition, the
formation of the root being a completion of the process of tooth
development. Functionally it is, however, difficult to say that the
DENTAL SYSTEM 19
one is a higher form than the other, since they both serve important
and different purposes in the animal economy.
As is almost always the case in nature, intermediate conditions
between these two forms of teeth are met with. Thus some teeth,
as the molars of the Horse, and of many Rodents, are for a time
rootless, and have growing pulps producing very long crowns with
parallel sides, the summits of which may be in use and beginning
to wear away while the bases are still growing ; but ultimately the
pulp contracts, forms a neck and distinct roots, and ceases to grow.
The canine tusks of the Musk Deer and of the Walrus have
persistent pulps, and are open at their base until the animal is of
advanced age, when they close, and the pulp ceases to be renewed.
The same sometimes happens in the tusks of very old Boars.
The simplest form of the crown of a tooth is that of a cone ;
but this may be variously modified. Thus it may be flattened, with its
edges sharp and cutting, and pointed at the apex, as in the laterally
compressed premolars of most Carnivora ; or it may be chisel- or
awl-shaped, with a straight truncated edge, as in the human incisors ;
or it may be broad, Avith a flat or rounded upper surface. Very
often there is a more or less prominent ridge encircling the whole or
part of the base of the crown just above the neck, called the cingu-
lum, which serves as a protection to the edge of the gum in masti-
cating, and is most developed in flesh -eating and insectivorous
animals, in which the gums are liable to be injured by splinters of
bone or other hard fragments of their food. The form of the
crown is frequently rendered complex by the development upon its
surface of elevations or tubercules called cusps or cones, or by
ridges usually transverse, but sometimes variously curved or folded.
When the crown is broad and the ridges are greatly developed, as
in the molars of the Elephant, Horse, and Ox (Fig. 1, V.), the inter-
spaces between them are filled with cement, which supports them
and makes a solid compact mass of the whole tooth. When such a
tooth wears away at the surface by friction against the opposed
tooth of the other jaw, the different density of the layers of
the substances of which it is composed — enamel, dentine, and
cement — arranged in characteristic patterns, causes them to wear
unequally, the hard enamel ridges projecting beyond the others,
and thus giving rise to a grinding surface of great mechanical
advantage.
Succession. — The dentition of all mammals consists of a definite
set of teeth, almost always of constant and determinate number,
form, and situation, and, with few exceptions, persisting in a
functional condition throughout the natural term of the animal's
life. In many species these are the only teeth which the animal
ever possesses, — the set which is first formed being permanent, or, if
accidentally lost, or decaying in extreme old age, not being replaced
2o GENERAL ANATOMICAL CHARACTERS
by others. These animals are called Monophyodont. But in the
larger number of mammals, certain of the teeth are preceded by
others, which may be only of a very transient, rudimentary, and
functionless character (being in the Seals, for example, shed either
before or within a few days after birth), or may be considerably
developed, and functionally occupy the place of the permanent teeth
for a somewhat lengthened period, during the growth and develop-
ment of the latter and of the jaws. In all cases these teeth
disappear (by the absorption of their roots and shedding of the
crowns) before the frame of the animal has acquired complete
maturity, as evidenced by the coalescence of the epiphyses of the
osseous system. As these teeth are, as a general rule, present
during the period in which the animal is nourished by the milk of
the mother, the name of "milk-teeth" (French dents cle lait,
German milchztihne) has been commonly accorded to them, although
it must be understood that the epoch of their presence is by no
means necessarily synchronous with that of lactation. Animals
possessing such teeth are called Diphyodont. No mammal is known
to have more than two sets of teeth ; and the definite and orderly
replacement of certain members of the series is a process of quite a
different nature from the indefinite succession which takes place in
all the teeth continuously throughout the lifetime of the lower
vertebrates.
AVhen the milk-teeth are well developed, and continue in place
during the greater part of the animal's growth, as is especially the
case with the Ungulata, and, though to a less degree, with the
Primates and Carnivora, their use is obvious, since taken all together
they form structurally a complete epitome on a small scale of the
more numerous and larger permanent set (see Fig. 3), and, con-
sequently, are able to perform the same functions, while time is
allowed for the gradual maturation of the latter, and especially
while the jaws of the growing animal are acquiring the size and
strength sufficient to support the permanent teeth. Those animals,
therefore, that have a well-developed and tolerably persistent set of
milk-teeth may be considered to be in a higher state of development,
as regards their dentition, than those that have the milk-teeth
absent or rudimentary.
It is a very general rule that individual teeth of the milk and
permanent set have a close relationship to one another, being
originally formed, as mentioned above, in exceedingly near proximity,
and with, at all events so far as the enamel-germ is concerned, a
direct connection. Moreover, since the latter ultimately come to
occupy the position in the alveolar border temporarily held by the
former, they are spoken of respectively as the predecessors or suc-
cessors of each other. But it must be understood that milk-teeth
may be present which have no successors in the permanent series,
DENTAL SYSTEM 21
and, what is far more general, permanent teeth may have no pre-
decessors in the milk series.
The complete series of permanent teeth of most mammals forms
a complex machine, with its several parts adapted for different
functions, — the most obvious structural modification for this purpose
being an increased complexity of the individual components of the
series from the anterior towards the posterior extremity of such
series. Since, as has just been said, the complete series of the milk
teeth often presents structurally and functionally a similar machine,
but composed of fewer individual members, and the anterior of which
are as simple, and the posterior as complex as those occupying
corresponding positions in the permanent series, — and since the
milk-teeth are only developed in relation to the anterior or lateral,
never to the most posterior of the permanent series, — it follows
that the hinder milk-teeth are usually more complex than the teeth
of which they are the predecessors in the permanent series, and
represent functionally, not their immediate successors, but those
more posterior permanent teeth which have no direct predecessors.
This character is clearly seen in those animals in which the various
members of the molar series are well differentiated from each other
in form, as the Carnivora, and also in Man.
In animals which have two sets of teeth the number of those
of the permanent series which are preceded by milk-teeth varies
greatly, being sometimes, as in Marsupials and some Rodents, as
few as one on each side of each jaw, and sometimes including the
larger portion of the series.
Although there are difficulties in some cases in arriving at a
satisfactory solution of the question, it is, on the whole, safest to
assume that when only one set of teeth is present, this corresponds
to the permanent teeth of the Diphyodonts. When this one set
is completely developed, and remains in use throughout the
animal's life, there can be no question on this subject. When, on
the other hand, the teeth are rudimentary and transient, as in the
Whalebone Whales, it is possible to consider them as representing
the milk series ; but there are weighty reasons in favour of the
opposite conclusion. 1
Arrangement, Homologies, and Notation of Teeth.— The teeth of
the two sides of the jaws are always alike in number and character,
1 This and other questions concerning the homologies, notation, and suc-
cession of the teeth of mammals are more fully developed in two memoirs hy one
of the present writers : — " Remarks on the Homologies and Notation of the Teeth
of the Mammalia," in the Journal of Anatomy and Physiology, vol. iii. p. 262,
1869; and "Notes on the First or Milk Dentition of the Mammalia," in the
Tnnis. Odontological Society of Great Britain, 1871. See also an important
memoir by Oldfield Thomas on the "Homologies and Succession of the teeth
in the Dasyuridse," Phil. Trans. 1887, pp. 443-462.
22
GENERAL ANATOMICAL CHARACTERS
except in cases of accidental or abnormal variation, and in the one
remarkable instance of constant deviation from bilateral symmetry
among mammals, the tusks of the Narwhal (Monodon), in which
the left is of immense size, and the right rudimentary. In cer-
tain mammals, such as the Dolphins and some Armadillos, which
have a very large series of similar teeth, not always constant in
number in different individuals, there may be differences in the two
sides ; but, apart from these, in describing the dentition of any
mammal, it is quite sufficient to give the number and characters
of the teeth of one side only. Since the teeth of the upper and the
lower jaws work against each other in masticating, there is a general
correspondence or harmony between them, the projections of one
series, when the mouth is closed, fitting into correspondingdepressions
of the other. There is also a general resemblance in the number,
characters, and mode of succession of both series, so that, although
individual teeth of the upper and lower jaws may not be in any
strict sense of the term homologous parts, there is a great con-
venience in applying the same descriptive terms to the one as are
used for the other.
The simplest dentition as a whole is that of many species of
Dolphin (Fig. 2), in which the crowns are single-pointed, slightly
Fio. 2.— Upper and Lower Teeth of one side of the Mouth of a Dolphin (Lagenorhynchus) as an
example of the homodont type of dentition. The bone covering the outer side of the roots of
the teeth has been removed to show their simple character.
curved cones, and the roots also single and tapering, and all alike in
form from the anterior to the posterior end of the series, though it
may be with some slight difference in size, those at the two extremities
of the series being rather smaller than the others. Such a dentition
is called Homodont, and in the case cited, as the teeth are never
changed, it is also Monophyodont. Such teeth are adapted only
for catching slippery living prey, as fish.
In a very large number of mammals the teeth of different
parts of the series are more or less differentiated in character,
and have different functions to perform. The front teeth are
simple and one-rooted, and are adapted for cutting and seizing.
They are called " incisors." The back- or cheek-teeth have broader
and more complex crowns, tuberculated or ridged, and are sup-
PF.XTAL SYSTEM
23
ported on two or more roots. They crush or grind the food, and
are hence called "molars." Many animals have, between these
two sets, a tooth at each corner of the mouth, longer and more
pointed than the others, adapted for tearing or stabbing, or for
fixing struggling prey. From the conspicuous development of
such teeth in the Carnivora, especially the Dogs, they have received
the name of "canines." A dentition with its component parts so
differently formed that these distinctive terms are applicable to
them is called Heterodont. In most cases, though by no means
invariably, animals with Heterodont dentition are also Diphyodont.
This general arrangement is extremely obvious in a considerable
number of mammals; and closer examination shows that, under
very great modification in detail, there is a remarkable uniformity
of essential characters in the dentition of a large number of
members of the class belonging to different orders and not otherwise
closety allied ; so much so indeed that it has been possible (chiefly
through the researches of Sir Richard Owen) to formulate a common
plan of dentition from which the others have been derived by the
alteration of some and suppression of other members of the series,
and occasionally, but very rarely, by addition. The records of
palaeontology fully confirm this view, as by tracing back many
groups now widely separated in dental characters we find a
gradual approximation to a common type. In this generalised form
of mammalian dentition (which is best exemplified in the genera
Anoplotherium and Homalodontotherium) the entire number of teeth
present is 44, or 11 above and 11 below on each side. Those of
each jaw are placed in continuous series without intervals between
them ; and, although the anterior teeth are simple and single-
rooted, and the posterior teeth complex and with several roots,
the transition between the two kinds is gradual.
In dividing and grouping such teeth for the purpose of descrip-
tion and comparison, more definite characters are required than
those derived merely from form or function. The first step towards
a classification has been made by the observation that the upper
jaw is composed of two bones, the j)remaxilla and the maxilla,
and that the suture between these bones separates the three
anterior teeth from the others. These three teeth, then, which are
implanted by their roots in the premaxilla, form a distinct group,
to which the name of ".incisor " is applied. This distinction is,
however, not so important as it aj)pears at first sight, for, as
mentioned when speaking of the development of the teeth, their
connection with the bone is only of a secondary nature, and, although
it happens conveniently for our purpose that in the great majority
of cases the segmentation of the bone coincides with the interspace
between the third and fourth tooth of the series, still, when it does
not happen to do so, as in the case of the Mole, we must not give
24 GENERAL ANATOMICAL CHARACTERS
too much weight to this fact, if it contravenes other reasons for
determining the homologies of the teeth. The eight remaining
teeth of the upper jaw offer a natural division, inasmuch as the
posterior three never have milk-predecessors ; and, although some
of the anterior teeth may be in the same case, the particular one
preceding these three always has such a predecessor. These three
then are grouped apart as the " molars," or, since some of the teeth
in front of them often have a molariform character, " true molars."
Of the five teeth between the incisors and molars the most anterior,
or that which is usually situated close behind the premaxillary
suture, almost always, as soon as any departure takes place from
the simplest and most homogeneous type, assumes a lengthened
and pointed form, and is the tooth so developed as to constitute
the " canine " or " laniary " tooth of the Carnivora, the tusk of the
Boar, etc. It is customary therefore to call this tooth, whatever
its size or form, the " canine." The remaining four are the " pre-
molars " or "false molars." This system of nomenclature has been
objected to as being artificial, and in many cases not descriptive,
the distinction between premolars and canine especially being
sometimes not obvious ; but the terms are now in such general use,
and are so practically convenient — especially if, as it is best to do
in all such cases, we forget their original signification and treat
them as arbitrary signs — that it is not likely they will be super-
seded by any that have been proposed as substitutes for them.
AVith regard to the lower teeth the difficulties are greater,
owing to the absence of any suture corresponding to that which
defines the incisors above ; but since the number of the teeth is
the same, the corresponding teeth are preceded by milk-teeth, and
in the large majority of cases it is the fourth tooth of the series
which is modified in the same way as the canine (or fourth tooth)
of the upper jaw, it is quite reasonable to adopt the same divisions
as with the upper series, and to call the first three, which are
implanted in the part of the mandible opposite to the premaxilla,
the incisors, the next the canine, the next four the premolars, and
the last three the molars. It may be observed that when the
mouth is closed, especially when the opposed surfaces of the teeth
present an irregular outline, the corresponding upper and lower
teeth are not exactly opposite, otherwise the two series could not
fit into one another ; but as a rule the points of the lower teeth
shut into the interspaces in front of the corresponding teeth of the
upper jaw. This is seen very distinctly in the canine teeth of the
Carnivora, and is a useful guide in determining the homologies of
the teeth of the two jaws. Objections have certainly been made
to this view, because, in certain rare cases, the tooth which, accord-
ing to it, would be called the lower canine has the form and
function of an incisor (as in Ruminants and Lemurs), and on the
DENTAL SYSTEM 25
other hand (as in Cotylops,axi extinct Ungulate from North America)
the tooth that would thus he determined as the first premolar has
the form of a canine ; hut it should not he forgotten that, as in all
such cases, definitions derived from form and function alone are
quite as open to objection as those derived from position and
relation to surrounding parts, or still more so.
lh iit<tl formula'. — For the sake of brevity the complete dentition,
arranged according to these principles, is often described by the
following formula, the numbers above the line representing the
teeth of the upper, those below the line those of the lower jaw : —
. . 3-3 • 1-1 , 4-4 , 3-3 11-11
incisors — , canines - — -, premolars - — 7 . molars r — - = — — — :
3-3 1 - 1 L 4-4 3-3 11-11
total 44. Since, however, initial letters may be substituted for
the names of each group, and it is quite unnecessary to give more
than the numbers of the teeth on one side of the mouth, the
formula may be conveniently abbreviated into —
* f » c h P b m f = tt J total 44 -
The individual teeth of each group are always enumerated from
before backwards, and by such a formula as the following —
i 1, i 2, i 3, c, p 1, p 2, p 3, p 4, m 1, m 2, m 3
i 1, i 2, i 3, c, p 1, p 2, p 3, p 4, m 1, m 2, in 3
or more briefly —
. 1, 2, 3 1_ 1, 2, 3, 4 1, 2, 3
1 1, 2, 3' C 1' P 1, 2, 3, 4' m 1, 2, 3'
A special numerical designation is thus given by which each one
can be indicated. In mentioning any single tooth, such a sign as Hi
will mean the first upper molar, ^n the first lower molar, and so on.
The use of such signs saves much time and space in description. 1
It was part of the view of the founder of this system of dental
notation that, at least throughout the group of mammals whose
dentition is derived from this general type, each tooth has its
strict homologue in all species, and that in those cases in which
fewer than the typical number are present (as in all existing
mammals except the genera Sus, Gymnura, Talpa, and Myogale), the
teeth that are missing can be accurately defined. According to
this view, when the number of incisors falls short of three it is
assumed that the absent ones are missing from the outer and
posterior end of the series. Thus, when there is but one incisor
present, it is i 1 ; when two, they are i 1 and i 2. Further-
more, when the premolars and the molars are below their typical
number, the absent teeth are missing from the fore part of the
premolar series, and from the back part of the molar series. If
this were invariably so, the labours of those who describe teeth
1 By many writers the letters indicating the different kinds of teeth are
printed in capitals, as /, C, P, and M ; while very frequently the symbol Pin is
employed in place of p.
26
GENERAL ANATOMICAL CHARACTERS
Avould be greatly simplified ; but there are so many exceptions that
a close scrutiny into the situation, relations, and development of a
tooth is required before its nature can be determined, and in some
cases the evidence at our disposal is scarcely sufficient for the
purpose. In other instances, however, as among the Polyprotodont
Marsupials, we have decisive evidence to show that the missing
premolar teeth are not those at the extremity of the series.
The milk -dentition is expressed by a similar formula, d
for deciduous or m for milk being commonly prefixed to the
-p.A-
17L.\ jji.z
(Zzf'i.a.3
JT
dm.\ dms. clm.z
m 2 m.z
Fio. 3. — Milk and Permanent Dentition of Upper (I.) and Lower (II.) Jaw of the Dog (Canis
familiaris), with the symbols by which the different teeth are commonly designated. The third
upper molar (m.3) is the only tooth wanting in this animal to complete the typical heterodont
mammalian dentition.
letter expressive of the nature of the tooth. Since the three
molars, and almost invariably the first premolar of the permanent
series, have no predecessors, the typical milk-dentition would be
expressed as follows — di §, dc \, dm 3, = -f, total 28. In a few
Ungulates, however, such as the Hyrax and Tapir, and in some
instances the Rhinoceros and the extinct Palceotherkun, the whole of
the four premolars are preceded by milk-teeth ; when we have the
fullest development of cheek-teeth in the whole of the Eutheria. The
teeth which precede the premolars of the permanent series are all
called molars in the milk-dentition, although as a general rule, in
DENTAL SYSTEM 17
form and function they represent in a condensed form the whole
premolar and molar series of the adult. When there is a marked
difference between the premolars and molars of the permanent
dentition, the first milk-molar resembles a premolar, while the last
has the characters of the posterior true molar.
The dentition of all the members of the orders Primates,
Carnivora, Insectivora, Chiroptera, and Ungulata can clearly be
derived from the above -described generalised type. The same
may be said of the Rodents, and even the Proboscidea, though
at least in the existing members of the order with greater modi-
fication. It is also apparent in certain extinct Cetacea, as
Z< uglodon and Squalodon, but it is difficult to find any traces of
it in existing Cetacea, Sirenia, or any of the so-called Edentata.
All the Marsupials, different as they are in their general structure
and mode of life, and variously modified as is their dentition,
present in this system of organs some deep-lying common characters
which show their unity of origin. The generalised type to which
their dentition can be reduced presents considerable resemblance
to that of the placental mammals, yet differing in details. It is
markedly heterodont, and susceptible of division into incisors,
canines, premolars, and molars upon the same principles. The
whole number is, however, not limited to forty-four. The incisors
may be as numerous as five on each side above, and they are
almost always different in number in the upper and the lower jaw.
The premolars and molars are commonly seven, as in the placental
mammals, but their arrangement is reversed, as there are four
true molars and three premolars.
The larger number of incisive and molar teeth among the
Marsupials suggests that their additional teeth have disappeared
in the Eutheria, 1 and Mr. 0. Thomas has endeavoured to construct
a generalised dental formula from which both the Marsupial and
Eutherian modifications may have been derived by the suppression
of particular teeth. Thus the hypothetical formula i ' 2 ' ' — — 5 >
C 1' & 1 *>' 3' 4 ' m 1 i 3' *~5» ky the loss of the fifth lower incisor,
and of the second premolars (which we know to be those which
disappear in the Marsupials) and the fifth molars, will give
* i; I i, X o > 4 ^mHH' ?n BHH' or the formula of the
Opossum (Didelphys), usually written i |, c \, p § , m £ . Again,
in the same formula the loss of the fourth and fifth incisors in
.12 3 1
both jaws, and also of the fourth molars, gives us i ' ' ' ' n , c ->
12 3 4 12 3 ^'
p ' ,7 ' , m ' ' ' or the formula of a typical Eutherian, like the
1, -, o, 4 1, Z,
1 According to Mr. G. E. Dobson there are four upper incisors in some of
the Soricidce.
28 GENERAL ANATOMICAL CHARACTERS
Pig, which we generally write as i %, c \, p f, m|. Such a
generalised formula will admit of modification into that of all
existing, and a large number of fossil Marsupials, but it is possible
that some of the Mesozoic types may have had more than four
premolars, although there is no absolutely decisive evidence that
such was the case. The presence of seven or eight true molars in
some Mesozoic forms merely entails the addition of two or three
additional figures to the ideal generalised formula.
The milk-dentition of all known Marsupials, existing or extinct,
is (if not entirely absent) limited to a single tooth on either side of
each jaw, this being the predecessor of the last permanent premolar.
And if the view that the milk -dentition is an additional series
grafted upon the original permanent series be correct, it is evident
that we have in this single replacement the first stage of this
additional development.
In very few mammals are teeth entirely absent. Even in the
Whalebone Whales their germs are formed in the same manner
and at the same period of life as in other mammals, and even
become partially calcified, but they never rise above the gums,
and completely disappear before the birth of the animal. In some
species of the order Edentata, the true Anteaters and the Pangolins,
no traces of teeth have been found at any age. The adult
Monotremata are likewise devoid of teeth of the same structure
as those of ordinary mammals ; but well-developed molars occur in
the young Ornithorhynchus, although no traces of teeth have hitherto
been detected in Echidna.
Modifications of the Teeth in Relation to their Functions. — The
principal functional modifications noticed in the dentition of
mammalia may be roughly grouped as piscivorous, carnivorous,
insectivorous, omnivorous, and herbivorous, each having, of course,
numerous variations and transitional conditions.
The essential characters of a piscivorous dentition are best
exemplified in the Dolphins, and also (as modifications of the
carnivorous type) in the Seals. This type consists of an elongated,
rather narrow mouth, wide gape, with numerous subequal, conical,
sharp-pointed, recurved teeth, adapted simply to rapidly seize, but
not to divide or masticate, active, slippery, but not powerful prey.
All animals which feed on fish as a rule swallow and digest them
entire, a process which the structure of prey of this nature, especially
the intimate interblending of delicate, sharp-pointed bones with the
muscles, renders very advantageous, and for which the above-
described type of dentition is best adapted.
The carnivorous type of dentition is shown in its most specialised
development among existing mammals in the Felidce. The function
being here to seize and kill struggling animals, often of large size
and great muscular power, the canines are immensely developed,
DENTAL SYSTEM 29
trenchant, and piercing, and are situated wide apart, so as to give
the firmest hold when fixed in the victim's body. The jaws are as
short as is consistent with the free action of the canines, so that no
power may be lost. The incisors are very small, so as not to
interfere with the penetrating action of the canines, and the
crowns of the molar series are reduced to scissor-like blades, with
which to pare oft' the soft tissues from the large bones, or to divide
into small pieces the less dense portions of the bones for the sake of
nutriment afforded by the blood and marrow they contain. The
gradual modification between this and the two following types will
be noticed in their appropriate places.
In the most typical insectivorous animals, as the Hedgehogs
and Shrews, the central incisors are elongated, pointed, and project
forwards, those of the upper and lower jaw meeting like the blades
of a pair of forceps, so as readily to secure small active prey, quick
to elude capture, but powerless to resist when once seized. The
crowns of the molars are covered with numerous sharp edges and
points, which, working against each other, rapidly cut up the hard-
cased insects into little pieces fit for swallowing and digestion.
The omnivorous type, especially that adapted for the con-
sumption of soft vegetable substances, such as fruits of various
kinds, may be exemplified in the dentition of Man, of most
Monkeys, and of the less modified Pigs. The incisors are moderate,
subequal, and cutting. If the canines are enlarged, it is usually
for other purposes than those connected with food, and only in the
male sex. The molars have their crowns broad, flattened, and
elevated into rounded tubercles. The name Bunodont, or hillock-
toothed, has been proposed for molars of this type, and will
frequently be found convenient.
In the most typically herbivorous forms of dentition, as seen in the
Horse and Kangaroo, the incisors are well developed, trenchant, and
adapted for cutting off the herbage on which the animals feed ; the
canines are rudimentary or suppressed ; the molars are large, with
broad crowns, which in the simplest forms have strong transverse
ridges, but may become variously complicated in the higher degrees
of modification which this type of tooth assumes.
Various forms of teeth of this type will be noticed among the
Ungulates and Rodents.
The natural groups of mammals, or those which in our present
state of knowledge we have reason to believe are truly related to
each other, may each contain examples of more than one of these
modifications. Thus the Primates have both omnivorous and
insectivorous forms. The Carnivora show piscivorous, carnivorous,
insectivorous, and omnivorous modifications of their common type
of dentition. The Ungulata and the Rodentia have among them
the omnivorous and various modifications, both simple and complex,
30 GENERAL ANATOMICAL CHARACTERS
of the herbivorous type. The Marsupialia exhibit examples of
all forms, except the purely piscivorous. Other orders, more
restricted in number or in habits, as the Proboscidea and Cetacea,
naturally do not show so great a variety in the dental structure of
their members.
Taxonomy. — In considering the taxonomic value to be assigned to
the modifications of teeth of mammals, two principles, often
opposed to each other, which have been at work in producing these
modifications, must be held in view: — (1) the type, or ancestral
form, as we generally now call it, characteristic of each group,
which in most mammals is itself derived from the still more
generalised type described above ; and (2) variations which have
taken place from this type, generally in accordance with special
functions which the teeth are called upon to fulfil in particular
cases. These variations are sometimes so great as completely to
mask the primitive type, and in this way the dentition of many
animals of widely different origin has come to present a remarkable
superficial resemblance, as in the case of the Wombat (a Marsupial),
the Aye- Aye (a Lemur), and the Eodents, or as in the case of the
Thylacine and the Dog. In all these examples indications may
generally be found of the true nature of the case by examining the
earlier conditions of dentition ; for the characters of the milk-
teeth or the presence of rudimentary or deciduous members of the
permanent set will generally indicate the route by which the
specialised dentition of the adult has been derived. It is perhaps
owing to the importance of the dental armature to the well-being
of the animal in procuring its sustenance, and preserving its life
from the attacks of enemies, that great changes appear to have
taken place so readily, and with such comparative rapidity, in the
forms of these organs — changes often accompanied with but little
modification in the general structure of the animal. Of this
proposition the Aye-Aye (Chiromyx) among Lemurs, the Walrus
among Seals, and the Narwhal among Dolphins form striking-
examples ; since in all these forms the superficial characters of their
dentition would entirely separate them from the animals with which
all other evidence (even including the mode of development of their
teeth) proves their close affinity.
Trituberculism. — Recent researches, and more especially those of
Professors Cope and Osborn, tend to show that almost all of the
extremely different forms of tooth-structure found among Mammals
may be traced to one common type, in Avhich the crown of each
tooth carried three cusps, and hence termed the tritubercular type ;
these three cusps being arranged in a triangle, with the apex
directed inwardly in the upper teeth (Fig. 4, e), and outwardly in
the lower ones (Fig. 4, 7). It is further probable that this
tritubercular type was itself derived from a type of dentition in
DENTAL SYSTEM
3i
which the teeth were in the form of almost a quite simple cone ;
such a presumably primitive type of dentition being apparently
retained among some existing Edentates, like the Armadillos, while
it is possible that we should regard the dentition of the existing
Cetacea (Fig. 2) as a reversion to the same primitive type. None of
the Mesozoic mammals at present known exhibit this simple
conical type of teeth, although we have an approximation to it in
the extremely generalised genus Dromatheriiou. Starting then
\
7a
hy-
/2
/J
Fig. 4. — Molar teeth of Mesozoic Mammals (enlarged). Triconodont type — 1, Dromatherium ;
2, M icrocoiiodon ; 3, Amphilestes ; 4, Phascolotherium ; 5, Triconodon. Tritubercular type — 0, 7,
Spalacotherium ; 10, Asthenodon. Tubercular sectorial type — S, Amphitherium ; 9, Peramus ; 11-
13, Amblotherium ; 14 (?) Amblotherium. pr, Protocone ; hy, hypocone ; pa, paracone ; me,
metacone, in the upper teeth ; and protoconid, hypoconid, paraconid, and metaconid in the
lower. 6 and 15 are upper molars, and the rest lower molars. (After Osborn.)
from this presumed simple cone it appears that the teeth of Droma-
therium (Fig. 4, i) present the first stage towards trituberculism, the
crown of each tooth having one main cone, with minute lateral
cusps, and the root being grooved. In the next or true Tricon-
odont stage (Fig. 4, 3-5) the crown has become elongated antero-
posteriorly, and consists of one central and two lateral cones or
cusps, while the root is divided. From this the transition is easy to
the tritubercular type, in which the three cusps, instead of being-
placed in a line, are arranged in a triangle ; the upper teeth (Fig.
32
GENERAL ANATOMICAL CHARACTERS
4, 6) having one inner and two outer cusps, while the reverse
condition obtains in those of the lower jaw (Fig. 4, 7). These
three cusps of the simple tritubercular tooth are collectively desig-
nated as the primitive triangle ; in the upper tooth the inner cusp
is termed the protocone, the antero-external one the paracone, and
the postero-external the metacone ; the corresponding cusps of the
lower tooth being named protoconid, paraconid, and metaconid —
the protoconid being here on the outer side of the crown.
It is thus apparent that in the first, or haplodont type, as well
as in the triconodont type, the upper and lower molars are alike ;
while in the simple tritubercular type they have a similar pattern,
but with the arrangement of the cusps reversed. This simple
tritubercular type occurs in the Mesozoic genus Spalacotherium
(Fig. 4, 6 and 7), and apparently in the existing Chrysochhris ; but
in the majority of tritubercular forms, while this primitive triangle
forms the main portion of the crown, other secondary cusps are
added, the homologies of which in the upper and lower teeth are
somewhat doubtful. At the same time that we have the addition
of these secondary cusps we also find trituberculism differentiating
into a secodont and a bunodont series, according as to whether the
dentition becomes of a cutting or a crushing type.
Thus in the lower molars (Fig. 4, s and 9) we very frequently
find the three cusps of the primitive triangle elevated and connected
by cross crests, while there is an additional low posterior heel or
talon, which may be termed the hypoconid. This tubercular-
sectorial sub-type, as it is termed, is found in the lower molars of
many Polyprotodont Marsupials and Insectivores, and it also occurs
in the lower carnassial teeth of the true Carnivora. The presence
of two cusps (inner and
outer) to the talon con-
verts this modification
into a quinquetubercular
form ; while, by the sup-
pression of one of the
three primitive cusps, it
develops into the quadri-
tubercular type of the
bunodont series.
In the upper molars
the primitive triangle in
the secodont series may
remain purely tricuspid ;
but the addition of in-
termediate cusps, both in the secodont and bunodont series, may give
rise to a quinquetubercular type ; these intermediate cusps being
respectively designated as the protoconule and metaconule (Fig. 5,
Fig. 5. — Diagram of two upper and two lower left
quadritubercular molars in mutual apposition. The cusps
and ridges of the upper molars in double lines, and those
of the lower in black lines. The lower molars are looked
at from below, as if transparent, pr, Protocone ; hy, hypo-
cone ; pa, paracone ; me, metacone ; ml, protoconule ; pi,
metaconule ; prd, protoconid ; hyd, hypoconid ; pad, para-
conid ; med, metaconid ; end, entoconid. (After Osborn.)
THE SKELETON 33
ml, pi). Finally, in the bunodont scries, the addition of a postero-
internal cusp (Fig. 5, h>i), termed the hypocone, forms the sextuber-
cular molar.
The following table exhibits, in a collective form, the names
and relations of all the above-mentioned cusps, and the letters by
which they are indicated in the figures : —
Upper Molars.
Antero-intemal cusp =protocone =pr.
Postero „ or 6th cusp = hypocone = hy.
Antero-external cusp =paracone = pa.
Postero ,, „ = metacone = me.
Anterior intermediate cusp = protoconule = ml.
Posterior „ „ =metaconule —pi.
Lower Molars.
Antero-external cusp =protoconid = 2ird.
Postero „ ,, =hypoconid =hyd.
Antero-internal or 5th cusp =paraconid =pad.
Intermediate (or in quadritubercular
molars antero-internal) cusp. = metaconid = med.
Postero-internal cusp =entaconid = end.
The common occurrence of trituberculism in the mammals of
the earlier geological epochs is, as remarked by Osborn, very
significant of the uniformity of molar origin. Thus, among the
Mesozoic mammals (with the exception of the group known as
Multituberculata, in which the molars are constructed on a different
type), trituberculism occurs in the great majority of the genera;
while out of 82 species, belonging to five different suborders from
the Lowest or Puerco Eocene of the United States, all but four
exhibit this feature ; and the same holds good for the mammals of
the corresponding European horizon. At the present day trituber-
culism persists in the Lemuroidea, Insectivora, Carnivora, and Mar-
supialia. In the Carnivora there is a tendency to lose the meta-
conid, while in the bunodont molars of the Ungulata it is the
paraconid that disappears.
III. THE SKELETON.
Definition. — The skeleton is a system of hard parts, forming a
framework which supports and protects the softer organs and
tissues of the body. It consists of dense fibrous and cartilaginous
tissues, portions of which remain through life in this state, but the
greater part is transformed during the growth of the animal into
bone or osseous tissue. This is characterised by a peculiar
3
34 GENERAL ANATOMICAL CHARACTERS
histological structure and chemical composition, being formed
mainly of a gelatinous basis, strongly impregnated with salts of
calcium, chiefly phosphate, and disposed in a definite manner, con-
taining numerous minute nucleated spaces or cavities called lacuna?,
connected together by delicate channels or canaliculi, which radiate
in all directions from the sides of the lacuna?. Parts composed of
bone are, next to the teeth, the most imperishable of all the organs
of the body, often retaining their exact form and internal structure
for ages after every trace of all other portions of the organisation
has completely disappeared, and thus, in the case of extinct animals,
affording the only means of attaining a knowledge of their characters
and affinities. 1
In the Armadillos and their extinct allies alone is there an
ossified exoskeleton, or bony covering developed in the skin. In
all other mammals the skeleton is completely internal. It may be
described as consisting of an axial portion belonging to the head
and trunk, and an appendicular portion belonging to the limbs.
There are also certain bones called splanchnic, being developed
Avithin the substance of some of the viscera. Such are the os cordis
and os penis found in some mammals.
It is characteristic of all the larger bones of the mammalia that
their ossification takes its origin from several distinct centres. One
near the middle of the bone, and spreading throughout its greater
portion, constitutes the diaphysis, or "shaft," in the case of the long
bones. Others near the extremities, or in projecting parts, form
the epiphyses, which remain distinct during growth, but ultimately
coalesce with the rest of the bone.
Axial skeleton. — The axial skeleton consists of the skull, the
vertebral column (prolonged at the posterior extremity into the
tail), the sternum, and the ribs.
Skull. — In the skull of adult mammals, all the bones, except the
lower jaw, the auditory ossicles, and the bones of the hyoid arch,
are immovably articulated together, their edges being in close con-
tact, and often interlocking by means of fine denticulations project-
ing from one bone and fitting into corresponding depressions of the
other ; they are also held together by the investing periosteum, or
fibrous membrane, which passes directly from one to the other,
and permits no motion, beyond perhaps a slight yielding to external
pressure. In old animals there is a great tendency for the different
bones to become actually united by the extension of ossification
from one to the other, with consequent obliteration of the sutures.
1 See for the principal modifications of the skeleton of the class, the large
and beautifully illustrated Ost6ographie of De Blainville, 1835-54 ; the section
devoted to the subject in Bronn's Klasscn und Ordnungen des Thicr-Rcichs, by
Giebel, 1874-79 ; and An Introduction to the Osteology of the Mammalia, by
W. II. Flower, 3d ed., 1885.
THE SKELETON
o
The cranium, thus formed of numerous originally independent
ossifications, which may retain throughout life more or less of their
individuality, or be all fused together, according to the species, the
age, or even individual peculiarity, consists of a brain-case, or bony
capsule for enclosing and protecting the brain, and a face for the
support of the organs of sight, smell, and taste, and of those concerned
in seizing and masticating the food. The brain-case articulates
directly with the anterior cervical vertebra, by means of a pair
of oval eminences, called condyles, placed on each side of the large
median foramen which transmits the spinal cord. It consists of a
basal axis, continuous serially with the axes or centra of the
Pa
IJP
jcO
Fig. 6. — Longitudinal and vertical section of the skull of a Dog (Canis famillaris), with
mandible and hyoid arch, an, Anterior narial aperture ; MT, maxillo-turbinal bone ; ET, ethmo-
turbinal ; Na, nasal ; ME, ossified portion of the mesethmoid ; CE, cribriform plate of the
ethmo-turbinal : Fr, frontal ; Pa, parietal ; IP, interparietal ; SO, supraoccipital ; ExO, ex-
occipital ; BO, basioccipital ; Per, periotic ; BS, basisphenoid ; Pt, pterygoid ; AS, ali-
sphenoid ; OS, orbitosphenoid ; PS, presphenoid ; PI, palatine ; VO, vomer ; Mx, maxilla ;
PMx, premaxilla ; sh, stylohyal ; eh, epihyal ; ch, ceratohyal ; bh, basihyal ; th, thyrohyal ;
s, symphysis of mandible ; cp, coronoid process ; cd, condyle ; a, angle ; id, inferior dental
canal. The mandible is displaced downwards, to show its entire form ; the * indicates the
part of the cranium to which the condyle is articulated. 1
vertebra?, and of an arch above, roofing over and enclosing the
cavity which contains the cephalic portion of the central nervous
system (see Fig. 6). The base with its arch is composed of three
segments placed one before the other, each of which is comparable
to a vertebra with a greatly expanded neural arch. The hinder or
1 This and many of the following figures in this chapter are taken from Flower's
Osteology of the Mammalia.
tf GENERAL ANATOMICAL CHARACTERS
j
occipital segment consists of the basioccipital, exoccipital, and
supraoccipital bones ; the middle segment of the basisphenoid, ali-
sjmenoid, and parietal bones ; and the anterior segment of the
presphenoid, orbitosphenoid, and frontal bones. The axis is
continued forwards into the mesethmoid, or septum of the nose,
around which the bones of the face are arranged in a manner
so extremely modified for their special purposes that anatomists
Avho have attempted to trace their serial homologies with the more
simple portions of the axial skeleton have arrived at very diverse
interpretations. The characteristic form and structure of the face
of mammals is mainly dependent upon the size and shape of (1) the
orbits, a pair of cup-shaped cavities for containing the eyeball and
its muscles, which may be directed forwards or laterally, placed
near together or wide apart, and may be completely or only partially
encircled by bone ; (2) the nasal fossa?, or cavities on each side of
the median nasal septum, forming the passage for the air to pass
between the external and the internal nares, and containing in their
upper part the organ of smell ; (3) the zygomatic arch, a bridge of
bone for the purpose of muscular attachment, which extends from
the side of the face to the skull, overarching the temporal fossa ;
(4) the roof of the mouth, with its alveolar margin for the implanta-
tion of the upper teeth. The face is completed by the mandible, or
lower jaw, consisting of two lateral rami, articulated by a hinge
joint with the scpiamosal (a cranial bone interposed between the
posterior and penultimate segment of the brain-case, where also the
bony capsule of the organ of hearing is placed), each being composed
of a single solid piece of bone, and the two united together in the
middle line in front, at the symphysis, — which union may be per-
manently ligamentous or become completely ossified. Into the
upper border of the mandibular rami the lower teeth are implanted.
In addition to the bones already mentioned as entering into the
formation of the cranium, there are many others, the most import-
ant of which may be briefly noticed. The anterior extremity of the
skull is formed by the premaxillse (Figs. 6, 7, PMx), which carry the
incisors ; behind them are the maxilla?, in which all the remaining
upper teeth are implanted. Both the premaxillse and maxilla? meet
in a median suture on the palate, where they form a floor to the nasal
passage ; this floor being continued backwards by the plate-like pala-
tines, at the hinder extremity of which the posterior nares are usually
situated. In a few instances, however, as in certain Edentates and
Cetaceans, the small pair of bones forming the posterior continuation
of the lateral borders of the palatines, and known as the pterygoids
(Fig. 6, Pt), likewise meet in the middle line below the nasal passage,
and thus cause the aperture of the posterior nares to be situated
near the occiput. On the upper, or frontal aspect of the cranium the
paired nasals roof over the nasal passage and fill the interval left
THE SKELETON
37
VJSls
Per
Fig. 7. — Side view of skull of Cape Jumping Hare (Pedetes
caffer). xj. PMx, Premaxilla ; Mr, maxilla; Ma, jugal or
malar ; Fr, frontal ; L, lachrymal ; Pa, parietal ; Na, nasal ;
Sq, squamosal ; Ty, tympanic ; ExO, exoccipital ; AS, alisphen-
oid ; OS, orbitosphenoid ; Per, mastoid bulla.
between the premaxilla and maxilla of either side. Behind the nasals
and maxilla 1 , the anterior part of the brain-case is formed by the
large paired frontals (Figs. 6, 7, Fr), behind which are the parietals,
which ma) T be of still
larger size, and form
the great it part of
the brain -case. A
median interparietal
ossification (Fig. 6,
IP) may divide the
parietals posteriorly,
and is itself articu-
lated with the supra-
occipital, to the lat-
eral borders of Avhich
the parietals are also
joined. The squam-
osal (Fig. 7, Sq) forms
the lateral wall of
the hinder part of
the brain -case, and
articulates superiorly with the parietal, and posteriorly with the
exoccipital. The glenoid cavity (Fig. 8), for the reception of the
articular condyle of the mandible, is formed by the inferior portion
of the squamosal, at the point where it gives off the zygomatic
process to form the hinder portion of the zygomatic arch. The
middle portion of that arch is formed by the jugal, or malar bone
(Fig. 7, Ma), which articulates posteriorly with the zygomatic process
of the squamosal, and anteriorly Avith the maxilla. The jugal (as
in Fig. 7) may also articulate with a small bone situated on the
anterior border of the orbit known as the lachrymal. It is im-
portant to observe that the zygomatic or temporal arch is a
squamoso-maxillary one, and that an arcade thus composed is found
elsewhere only among the extinct Anomodont reptiles, which have
already been mentioned as showing signs of mammalian affinity.
The relative position occupied by the orbito- and alisphenoid is
sufficiently indicated in Fig. 7.
Wedged in between the squamosal and the bones of the occipital
and basisphenoidal region are the bones connected with the organ
of hearing, known as the periotic and tympanic. The position of
the periotic, which encloses the labyrinth or essential organ of
hearing, is shown in Fig. 6. The periotic is divided into a very
dense antero-internal moiety known as the petrosal, and a postero-
external or mastoid portion (Fig. 8), which appears on the outer Avail
of the brain-case. The tympanic is produced horizontally outwards
to form the external auditory meatus or tube of the ear, Avhile the
38
GENERAL ANATOMICAL CHARACTERS
inner and under surface is frequently dilated into a shell-like
auditory bulla (Fig. 8). The small bones of the internal ear known
as the malleus, incus, and stapes are contained in the membranous
tympanic cavity,
which is situated in
a space left among
this group of bones.
Further mention of
these bones is made
below under the
head of the sense
C2J-
organs.
In the Carni-
vora and some other
groups the foram-
ina on the base of
the skull for the
passage of blood-
vessels and nerves
are of considerable
taxonomic import-
ance. The position
of the more im-
portant of these
foramina is indi-
cated in Fig. 8 ;
but for details the
reader may refer to
the work on the
Osteology of theMam-
malia already men-
tioned. Attention
may, however, be
particularly di-
rected tO the SO-
sphenoid canal ; P, paroccipital process of exoccipital ; m, mastoid ,, , ,. , .-.
process of periotic ; am, external auditory meatus ; g, glenoid for- Called allspnenOlCl
amen, below which is the glenoid cavity for the condyle of the man- canal, the position
dible. (Flower, Proc. Zool. Soc, 1869, p. 25.) _£ -lylijf;^ jg shown
in Fig. 8, since this is a feature of some importance in the classifica-
tion of the Carnivora. This canal is a short channel running hori-
zontally forward from near the foramen ovale through the alisphenoid,
and opening anteriorly with the foramen rotundum ; it is traversed
by the external carotid artery.
Only in those species, as Man and the smaller kinds of the
Primates and some other orders, in which the brain holds a large
relative proportion to the rest of the body, does the external form
Fig. 8.— The right half of the hinder part of the base of the
cranium of the Wolf (Canis lupus), c, Condyloid foramen ; I, fora-
men lacerum posticum ; car, carotid canal ; e, eustachian canal ;
o, foramen ovale ; a, posterior, and a', anterior aperture of ali
THE SKELETON 39
of the skull receive much impress from the real shape of the cavity
containing the brain. The size and form of the mouth, and the
modifications of the jaws for the support of teeth of various shape
and number, the ridges and crests on the cranium for the attachment
of the muscles necessary to put this apparatus in motion, and out-
growths of bone for the enlargement of the external surface required
for the support of sense organs or of weapons, such as horns or
antlers (which outgrowths, to prevent undue increase of weight, are
filled with cells containing air), cause the principal variations in the
general configuration of the skull. These variations are, however,
only characteristically developed in perfectly adult animals, and are
in many cases more strongly marked in the male than the female
sex. Throughout all the later stages of growth up to maturity the
size and form of the brain-case remain comparatively stationary,
while the accessory parts of the skull rapidly increase and assume
their distinctive development characteristic of the species.
The hyoidean apparatus in mammals (Fig. 6) supports the tongue
and larynx, and consists of an inferior median portion termed the
basihyal, from which two pairs of half arches, or cornua, extend up-
wards and outwards. The anterior is the more important, being
connected with the periotic bone of the cranium. It may be almost
entirely ligamentous, but more often has several ossifications, the
largest of which is usually the stylohyal. The posterior cornu
(thyrohyal) is united at its extremity with the thyroid cartilage of
the larynx, which it suspends in position. The median portion,
or basihyal, is sometimes, as in the Howling Monkeys, enormously
enlarged and hollowed, admitting into its cavity an air-sac connected
with the organ of voice.
Vertebral Column. — The vertebral column consists of a series of
distinct bones called vertebra?, arranged in close connection with
each other along the dorsal side of the neck and trunk, and in the
median line. 1 It is generally prolonged posteriorly beyond the
trunk, to form the axial support of the appendage called the tail.
Anteriorly it is articulated with the occipital region of the skull.
The number of distinct bones composing the vertebral column
varies greatly among the Mammalia, the main variation being
due to the degree of elongation of the tail. Apart from this, in
most mammals the number is not far from thirty, though it may
fall as low as twenty-six (as in some Bats), or rise as high as
forty (Hyrax and Cholcepus). The different vertebrse, with some
exceptions, remain through life quite distinct from each other,
though closely connected by means of fibrous structures which
allow of a certain, but limited, amount of motion between them.
The exceptions are the following: — (1) near the posterior part
1 For the sake of uniformity, in all the following descriptions of the vertebral
column, the long axis of the body is supposed to be in the horizontal position.
4o
GENERAL ANATOMICAL CHARACTERS
of the trunk, in nearly all mammals which possess completely
developed hinder limbs, two or more vertebra? become ankylosed
together to form the " sacrum," or portion of the vertebral column
to which the pelvic girdle is attached ; (2) in some species of
Whales and Armadillos there are constant ossific unions of certain
vertebrae of the cervical region.
Although the vertebrae of different regions of the column of the
same animal or of different animals present great diversities of
form, yet there is a certain general resemblance among them, or a
common plan on which they are constructed, which is more or less
modified by alteration of form or proportions, or by the addition or
suppression of parts to fit them to fulfil their special purpose in the
economy. An ordinary or typical vertebra consists, in the first
place, of a solid piece of bone, termed the body or centrum (Fig.
9, c), of the form of a disk or short cylinder. The bodies of con-
az
JJZ
Fio. 9. — Anterior surface of Human
thoracic vertebra (fourth), c, Body or
centrum ; nc, neural canal ; p, pedicle,
and I, lamina of the arch ; t, transverse
process ; az, anterior zygapophysis.
Fig. 10. — Side view of the first lum-
bar vertebra of a Dog (Canis familiaris).
s, Spinous process ; az, anterior zygapo
physis ; pz, posterior zygapophysis ; m,
metapophysis ; a, anapophysis ; t, trans-
verse process.
tiguous vertebrae are connected together by a very dense, tough, and
elastic material called the " intervertebral substance," of peculiar and
complex arrangement. This substance forms the main, and in some
cases the only, union between the vertebrae. Its elasticity provides
for the vertebrae always returning to their normal relation to each
other and to the column generally, Avhen they have been disturbed
therefrom by muscular action. A process (p) arises on each side
from the dorsal surface of the body. These processes, meeting in
the middle line above, form an arch, surmounting a space or short
canal (nc). Since it contains the posterior prolongation of the
great cerebro-spinal nervous axis, or spinal cord, this space is called
the neural canal, and the arch the neural arch, in contradistinction
to another arch on the ventral surface of the body of the verte-
brae, called the haemal arch. The latter is, however, never formed
THE SKELETON 41
in mammals by any part of the vertebra itself, but by certain
distinct bones placed more or less in apposition to it, namely the
ribs in the thoracic, and the " chevron bones " in the caudal region.
In most cases the arch of one vertebra is articulated with that of
the next by distinct surfaces with synovial joints, placed one on
each side, called "zygapophyses " (az, pz), but these are often entirely
wanting when flexibility is more needed than strength, as in the
greater part of the caudal region of long-tailed animals. In addition
to the body and the arch, there are certain projecting parts called
processes, chiefly serving for the attachment of the numerous
muscles which move the vertebral column. Of these two are single
and median, viz. the spinous process, neural spine, or neurapophysis
(s), arising from the middle of the upper part of the arch, and the
hypapophysis from the under surface of the body. The latter, how-
ever, is as frequently absent as the former is constant. The other
processes are paired and lateral. They are the transverse processes
(/), of which there may be two, an upper and a lower, in which case
the former .is called, in the language of Owen (to whom we are
indebted for the terminology of the parts of vertebrae in common
use), " diapophysis," and the latter " parapophysis." Other processes
less constantly present are called respectively " metapophyses " (m)
and " anapophyses " (a).
The vertebral column is divided for convenience of description
into five regions — the cervical, thoracic or dorsal, lumbar, sacral, and
caudal. This division is useful, especially as it is not entirely
arbitrary, and in most cases is capable of ready definition ; but at
the contiguous extremities of the regions the characters of the
vertebra of one are apt to blend into
those of the next region, either normally
or as peculiarities of individual skeletons.
Cervical Vertebrae. — The cervical region
constitutes the most anterior portion of f^^^^^^p^^xaz
the column, or that which joins the
cranium. The vertebra which belong to
it are either entirely destitute of movable
ribs, or if they have any these are small,
and do not join the sternum. As a general
rule they have a considerable perforation
through the base of the transverse process
(the vertebrarterial canal, Fig. 11, v) ; or,
as it is sometimes described, they have s , spinous process ; az, anterior
two transverse processes, superior and zygapophysis ; v, vertebrarterial
Fig. 11. — Anterior surface of
sixth cervical vertebra of Dog.
canal ; t, transverse process ; t', its
inferior, which meet at their extremities inferior lamella .
to enclose a canal. This, however, rarely
applies to the last vertebra of the region, in which only the upper
transverse process is usually developed. The transverse process,
42 GENERAL ANATOMICAL CHARACTERS
moreover, very often sends down near its extremity a more or
less compressed plate (inferior lamella), which, being considered
serially homologous with the ribs of the thoracic vertebra? (though
not developed autogenously), is often called the " costal " or
" pleurapophysial " plate. This is usually largest on the sixth, and
altogether wanting on the seventh vertebra. The first and second
cervical vertebrae, called respectively "atlas" and "axis," are
specially modified for the function of supporting and permitting
the free movements of the head. They are not united together
by the intervertebral substance, but connected only by ordinary
ligaments and synovial joints.
The cervical region in mammals presents the remarkable
peculiarity that, whatever the length or flexibility of the neck, the
number of vertebrae is the same, viz. seven, with the exception of
the Manatee and Hoffman's Two-toed Sloth (Cholospus hoffmanni),
which both have but six, and the Three-toed Sloth (Bradyjms
tridactylus), which has nine, though in this case the last two usually
support movable ribs, which are not sufficiently developed to reach
the sternum.
According to Parker there may occasionally be eight cervicals
in the Pangolins (Manis).
Dorsal Vertebral. — The dorsal (or, as it would be more correctly
termed, thoracic) region consists of the vertebrae succeeding those
of the neck, which have ribs movably articulated to them. These
ribs arch round the thorax — the anterior one, and usually the
greater number of those that follow, being attached below to the
sternum.
Lumbar Vertebrce. — The lumbar region consists of those vertebrae
of the trunk in front of the sacrum which bear no movable ribs.
It may happen that, as the ribs decrease in size posteriorly (the
last being sometimes more or less rudimentary), the step from the
thoracic to the lumbar region may be gradual and rather undeter-
mined in a given species ; but most commonly this is not the
case, and the distinction is as well defined here as in any other
region. As a general rule there is a certain relation between the
number of the thoracic and lumbar vertebrae, the whole number
being tolerably constant in a given group of animals, and any
increase of the one being at the expense of the other. Thus in all
known Artiodactyle Ungulata there are 1 9 dorso-lumbar vertebrae ;
but these may consist of 1 2 dorsal and 7 lumbar vertebrae, or 1 3
dorsal and 6 lumbar, or 14 dorsal and 5 lumbar. The smallest
number of dorso-lumbar vertebrae in mammals occurs in some
Armadillos, which have but 14. The number found in Man,
the higher Apes, and most Bats, viz. 17, is exceptionally low;
19 prevails in the Artiodactyla, nearly all Marsupials, and very
many Rodents; 20 or 21 in Carnivora and most Insectivora ;
THE SKELETON
43
and 23 in Terissodactyla. The highest and quite exceptional
numbers are in the Two-toed Sloth (Choke/pus) 27, and the Hyxax
30. The prevailing number of rib-bearing vertebra? is 12 or 13,
any variation being generally in excess of these numbers.
Sacral Vertebra*. — The sacral region offers more difficulties o.
definition. Taking the human " os sacrum " as a guide for
comparison, it is generally defined as consisting of those vertebras
between the lumbar and caudal regions which are ankylosed
together to form a single bone. It happens, however, that the
number of such vertebras varies in different individuals of the
same or nearly allied species, especially as age advances, when a
certain number of the tail vertebras generally become incorporated
with the true sacrum. Other suggested tests — as those vertebras
which have a distinct additional (pleurapophysial) centre of ossifica-
tion between the body and the ilium, those to which the ilium is
directly articulated, or those in front of the insertion of the ischio-
sacral ligaments — being ecpially unsatisfactory or unpractical, the
old one of ankylosis, as it is found to prevail in the average
condition of adults in each species, is used in the enumeration of
the vertebras in the following pages. The Cetacea, having no iliac
bones, have no part of the vertebral column modified into a
sacrum.
Caudal Vertebra}. — The caudal vertebras are those placed behind
the sacrum, and terminating the vertebral column. They vary
in number greatly — being reduced to 5, 4, or even 3, in a most
rudimentary condition, in Man
and in some Apes and Bats, and
being numerous and powerfully
developed, with strong and com-
plex processes, in many mammals,
especially among the Edentata,
Cetacea, and Marsupialia. The
highest known number, 46, is
possessed by the African Long-
tailed Pangolin. Connected with
the under surface of the caudal
vertebras of many mammals which
have the tail well developed are
certain bones formed more or less
like an inverted arch, called chev-
ron bones, or by the French os en
V. These are always situated
nearly opposite to an interverte-
bral space, and are generally artic-
ulated both to the vertebra in front and the vertebra behind, but
sometimes chiefly or entirely either to one or the other.
Fig. 12. — Anterior surface of fourth
caudal vertebrae of Porpoise (Phoccena com-
munis), s, Spinous process ; m, metapophy-
sis ; t, transverse process ; h, chevron bone.
44
GENERAL ANATOMICAL CHARACTERS
ms'
In some of the Anomodont Keptiles and Labyrintkodont
Amphibians these chevrons are attached to the intercentra — or
imperfect disks alternating with the true centra — which suggests
that they are primarily intercentral elements which have been trans-
ferred to the edges of the centra by the disappearance of the inter-
centra.
Sternum. — The sternum of mammals is a bone, or generally a
series of bones, placed longitudinally in tke mesial line, on tke
inferior or ventral aspect of tke tkorax, and connected on eack side
Avitk tke vertebral column by a series
of more or less ossified bars called
" ribs." It is present in all mammals,
but varies muck in ckaracter in tke
different groups. It usually consists
of a series of distinct segments placed
one before tke otker, tke anterior
being called tke presternum or " manu-
brium sterni " of kuman anatomy, and
tke posterior tke xipkisternum, or
xipkoid or ensiform process, wkile tke
intermediate segments, Avkatever tkeir
number, constitute tke mesosternum
or " body." In tke Wkalebone Wkales
tke presternum alone is developed, and
but a single pair of ribs is attacked
to it.
Bibs. — Tke ribs form a series of
long, narrow, and more or less flattened
bones, extending laterally from tke
sides of tke vertebral column, curving
downwards towards tke median line
of tke body below, and mostly joining
tke sides of tke sternum. Tke posterior
ribs, kowever, do not directly articulate
witk tkat bone, but are eitker attacked by tkeir extremities to
tke edges of eack rib in front of tkem, and tkus only indirectly
join tke sternum, or else tkey are quite free below, meeting no part
of tke skeleton. Tkese differences kave given rise to tke division
into " true " and " false " ribs (by no means good expressions), signi-
fying tkose tkat join tke sternum directly and tkose tkat do not ;
and of tke latter, tkose tkat are free below are called " floating "
ribs. Tke portion of eack rib nearest tke vertebral column and
tkat nearest tke sternum differ in tkeir ckaracters, tke latter being
usually but imperfectly ossified, or remaining permanently cartila-
Fig. 13. -Human sternum and
sternal ribs, ps, Presternum ; ms,
mesosternum ; xs, xiphisterimm ; c,
point of attachment of clavicle ; 1 to
10, the cartilaginous sternal ribs.
Tkese are called " costal cartilages," or wken ossified
" sternal ribs."
THE SKELETON
45
In the anterior part of the thorax the vertebral extremity of
each rib is divided into two parts, " head " or " capitnlum," and
"tubercle"; the former is attached to the side of the body of the
vertebra, the latter to its
transverse process ; the
former attachment corre-
sponds to the interspace
between the vertebra?, the
head of the rib commonly
articulating partly with
the hinder edge of the
body of the vertebra ante-
cedent to that which bears
its tubercle. Hence the
body of the last cervical
vertebra usually supports
part of the head of the first
rib. In the posterior part
of the series the capitular
and tubercular attach-
ments commonly coalesce,
and the rib is attached
solely to its corresponding
vertebra. The number of pairs of ribs is of course the same as that
of the thoracic vertebrae.
The circumstance that in some of the Anomodont reptiles and
Fig. 14.— Sternum and strongly ossified sternal ribs
of Great Armadillo (Priodon gigas). j>s, Presternum;
xs, xiphisternum.
Fig. 15. — Skeleton of Lion (Felis ho), cd, Caudal vertebrae ; cp, carpus ; cr, coraeoid process
of scapula ; cv, cervical vertebrae ; d, dorsal vertebra; ; fb, fibula ; fm, femur ; h, humerus ; il,
ilium ; isch, ischium ; I, lumbar vertebras ; m, metatarsus ; mc, metacarpus ; p, patella ; pb, pubis ;
ph, phalanges ; pv, pelvis ; r, radius ; s, sacral vertebrae ; sc, scapula ; sk, skull ; tb, tibia ; ts,
tarsus ; v., ulna ; zy, zygomatic arch.
Labyrinthodonts the capitula of the ribs articulate with the inter-
central elements of the vertebral column has suggested, as in the
46 GENERAL ANATOMICAL CHARACTERS
instance of the chevron bones, that the intercentral capitular articu-
lation of the ribs of mammals is a feature directly inherited
from those extinct types by the gradual disappearance of the
intercentra.
Appendicular Skeleton. — The appendicular portion of the frame-
work consists, when completely developed, of two pairs of limbs,
anterior and posterior (Fig. 15).
Anterior Limb. — The anterior limb is present and fully developed
in all mammals, being composed of a shoulder girdle and three seg-
ments belonging to the limb proper, viz. the upper arm or brachium,
the fore-ai'm or antebrachium, and the hand or manus.
Shoulder-girdle. — The shoulder or pectoral girdle'm the large majority
of mammals is in a rudimentary or rather modified condition, com-
pared with that in which it exists in other vertebrates. In the Mono-
tremata (Ornithorhynchus and Echidna) alone is the ventral portion, or
coracoid, complete and articulated with the sternum below, as in the
Sauropsida ; and in this group alone do we find an anterior ventral
element, apparently corresponding with the precoracoid of the Anom-
odont reptiles, although generally known as the epicoracoid. In all
other mammals the coracoid, though ossified from a distinct centre,
forms only a process, sometimes a scarcely distinct tubercle, projecting
from the anterior border of the glenoid cavity of the scapula. The
last-named cavity, which in the Monotremes is formed jointly by
the scapula and coracoid, receives the head of the humerus, or
arm-bone. The scapula is always well developed, and generally
broad and flat (whence its vernacular name " blade bone "), with a
ridge called the " spine " on its outer surface, which usually ends in
a free curved process, the "acromion." As the scapula affords
attachment to many of the muscles which act upon the anterior
limb, its form and the development of its processes are greatly
modified according to the uses to which the member is put. Thus it
is most reduced and simple in character in those animals whose limbs
are mere organs of support, as the Ungulates ; and most complex
when the limbs are also used for grasping, climbing, or digging.
The development or absence of the clavicle or " collar-bone," an
accessory bar which connects the sternum with the scapula and
steadies the shoulder-joint, has a somewhat similar relation, though
its complete absence in the Bears shows that this is not an invariable
rule. A complete clavicle is found in Man and all the Primates, in
Chiroptera, all Insectivora (except Potaniogale), in many Rodents, in
most Edentates, and in all Marsupials, except Perameles. More or
less rudimentary clavicles (generally suspended freely in the muscles)
are found in the Cat, Dog, and most Carnivora, Myrmecophaga, and
some Rodents. Clavicles are altogether absent in most of the I Wsidce,
all the Pinnipedia, Manis among Edentates, the Cetacea, Sirenia,
Ungulates, and some Rodents.
THE SKELETON
47
ig
a T-shaped
the sternum,
The Monotremcs are peculiar in possessin
interclavicle like that of many reptiles, lying upon
and articulating superiorly with the clavicles.
Brachiv/m and Antebrachium. — The proximal segment of the
anterior or pectoral limb proper contains a single bone, the humerus,
and the second segment two bones, the radius and the ulna, placed
side by side, and articulating with the humerus at their proximal,
and with the carpus at their distal extremity (Fig. 15). In their
primitive and unmodified condition these bones may be considered as
placed one on each border of the limb, the radius being preaxial or
anterior, and the ulna postaxial or posterior, when the distal or free
end of the limb is directed outwards, or away from the trunk. This
is their position in the earliest embryonic condition, and is best
illustrated among adult mammals in the Cetacea, where the two
bones are fixed side by side and parallel to each other. In the
greater number of mammals the bones assume a very modified and
adaptive position, usually crossing each other in the forearm, the
radius in front of the ulna, so that the preaxial bone (radius),
though external (in the ordinary position of the limb) at the upper
end, is intei'nal at the lower end ; and the hand, being mainly fixed
to the radius, also has its preaxial border internal. In the large
majority of mammals the bones are fixed in this position, but in
some few, as in Man, a free movement of crossing and uncrossing —
or pronation and supination, as it is termed — is allowed between
them, so that they can be placed in their primitive parallel condition,
when the hand (which moves with the radius)
is said to be supine, or they may be crossed,
when the hand is said to be prone.
The humerus frequently has a foramen
piercing the inner border of the distal
extremity, known as the entepicondylar
foramen, which corresponds with a similar
one found in the Anomodont reptiles. The
hollow in the head of the ulna for the recep-
tion of the head of the humerus is known
as the greater sigmoid cavity, and that for
the head of the radius as the lesser sigmoid
cavity (Fig. 16). The term olecranon is
applied to that process of the ulna which
forms the prominence of the elbow.
In most mammals Avalking on four limbs,
in which the hand is permanently prone, the
ulna is much reduced in size, and the radius
increased, especially at the upper end ; so
that the articular surface of the latter, instead of being confined to
the external side of the trochlea of the humerus, extends all across
Fig. 16. — Outer aspect of
the proximal extremity of the
right ulna of a Bear (Ursus).
a, Anterior tubercle ; ol,
olecranon ; 6, greater sigmoid
cavity ; c, lesser do.
4 8
GENERAL ANATOMICAL CHARACTERS
its anterior surface, and the two bones, instead of being external
and internal, are anterior and posterior. In many hoofed or Ungu-
late mammals, and in Bats, the ulna is reduced to little more than
its upper articular extremity, and firmly ankylosed to the radius
— stability of these parts being more essential than mobility.
Manas. — The terminal segment of the anterior limb is the hand
or maims. Its skeleton consists of three divisions : (1) the
" carpus," a group of small, more or less rounded or angular bones
with flattened surfaces applied to one another, and, though arti-
culating by synovial joints, having scarcely any motion between
them ; (2) the " metacarpus," a series of elongated bones placed side
by side, with their proximal ends articulating by almost immovable
joints with the carpus; (3) the "phalanges" or bones of the digits,
usually three in number to each, articulating to one another by freely
movable hinge- joints, the first being connected in like manner to
the distal end of the metacarpal bone to which it corresponds.
Carpus. — To understand thoroughly the arrangement of the
bones of the carpus in mammals, it is necessary to study their
condition in some of the lower vertebrates. Fig. 17 represents
the manus in one of its fullest and at the same time most
generalised forms, as seen in one of the
Water Tortoises (Chelydra serpentina). The
carpus consists of two principal rows of
bones. The upper or proximal row con-
tains three bones, to which Gegenbaur
has applied the terms radiate (r), inter-
medium (i), and uhiare (u), the first being
on the radial or preaxial side of the limb. 1
The lower or distal row contains five
bones, called carpale 1, 2, 3, 4, and 5
respectively, commencing on the radial
side. Between these two rows, in the
middle of the carpus, is a single bone,
the centrate (c). In this very symmetrical
carpus it will be observed that the radiate
supports on its distal side two bones,
carpale 1 and 2 ; the intermedium is in a
line with the centrate and carpale 3, which
together form a median axis of the hand,
while the ulnare has also two bones articu-
lating with its distal end, viz. carpale 4
and 5. Each of the carpals of the distal
row supports a metacarpal.
1 The opinion has recently been expressed by Baur that the bone termed
radiale in Fig. 17 is really a second centrale, and that the radiale is represented
by a minute bone generally known as the radial sesamoid. The mammalian
Fio. 17.— Dorsal surface of the
right inarms of a Water Tortoise
(Chelydra serpentina). After Ge-
genbaur. U, Ulna ; R, radius ; u,
ulnare ; i, intermedium ; r, radiale ;
c, centrale ; 1-5, the five bones of
the distal row of the carpus ; mi-
ni 5 , the five metacarpals.
THE SKELETON 49
In the carpus of the Mammalia there are usually two additional
bones developed in the tendons of the flexor muscles, one on each
side of the carpus, which may be called the radial and ulnar
sesamoid bones ; the latter, which is the more constant and generally
larger, is commonly known as the pisiform bone. The fourth and
fifth carpals of the distal row are always united into a single bone,
and the centrale is very often absent. As a general rule all the
other bones are present and distinct, though it not unfrequently
happens that two may have coalesced to form a single bone, or
one or more may be altogether suppressed.
The following table shows the principal names in use for the
various carpal bones, — those in the second column being the terms
generally employed by English anatomists : —
Radiale — Scaphoid = Naviculars
Intermedium = Lunar = Semilunare, Lunatum.
Ulnare = Cuneiform = Triquetrum, Pyramidale.
Centrale = Central = Intermedium (Cuvier).
Carpale 1 = Trapezium = Multangulum majus.
Carpale 2 = Trapezoid = Multangulum minus.
Carpale 3 = Magnum = Capitatum.
Carpale 4
Carpale 5
Unciform = Hamatum, Uncinatum.
The radial and ulnar sesamoids are regarded by Bardeleben l as
the rudiments of a prepollex and a postminimus digit ; the primitive
number of digits being thus supposed to have been seven. These
bones have been observed in all orders of mammals having five
complete digits. Occasionally, as in Peclctes caffer, the so-called
prepollex consists of two bones, of which the distal one bears a
distinct nail -like horny covering. In Bathyergus maritimus the
pisiform, or postminimus, is likewise double ; the two elements
being regarded by their describer as representing the carpal and
metacarpal of the presumed seventh digit.
Similarly in the posterior limb the tibial sesamoid, and a fibular
ossification corresponding to the pisiform, are regarded as represent-
ing a prehallux and a postminimus.
Metacarpus and Phalanges. — The metacarpal bones, with the
digits which they support, are never more than five in number, and
are described numerically — first, second, etc., counting from the
radial towards the ulnar side. The digits are also sometimes named
(1) the pollex, (2) index, (3) medius, (4) annularis, (5) minimus.
scaphoid is accordingly also regarded as a second centrale. In the same com-
munication, Dr. Baur expresses his disbelief in the existence of remnants of a
prepollex and of a seventh digit in mammals and other vertebrates. (See Anat.
Anzeiger, vol. iv. pp. 49-52, 1889.)
1 On the Prsepollex and Pramallux, etc., Proc. Zool. Soc. 1889, pp. 259-262.
4
50 GENERAL ANATOMICAL CHARACTERS
One or more may be in a rudimentary condition, or altogether
suppressed. If one is absent, it is most commonly the first.
Excepting the Cetacea, no mammals have more than three phalanges
to each digit, but they may occasionally have fewer by suppression
or ankylosis. The first or radial digit is an exception to the usual
rule, one of its parts being constantly absent, since, while each of the
other digits has commonly a metacarpal and three phalanges, it has
only three bones altogether ; whether the missing one is a meta-
carpal or one of the phalanges is a subject which has occasioned
much discussion, and has not yet been satisfactorily decided. The
terminal phalanges of the digits are usually specially modified to
support the nail, claw, or hoof, and are called " ungual phalanges."
In walking, some mammals (as the Bears) apply the whole of the
lower surface of the carpus, metacarpus, and phalanges to the
ground ; to these the term " plantigrade " is applied. Many others
(as nearly all the existing Ungulata) only rest on the last one or two
phalanges of the toes, the first phalanx and the metacarpals being
vertical and in a line with the fore-arm. These are called " digiti-
grade." Intermediate conditions exist between these two forms, to
which the terms " phalangigrade " (as the Camel) and " subplanti-
grade " (as in most Carnivora), are applied. When the weight is
borne entirely on the distal surface of the ungual phalanx, and the
horny structures growing around it, as in the Horse, the mode of
progression is called " unguligiade."
In the Chiroptera the digits are enormously elongated, and
support a cutaneous expansion constituting the organ of flight. In
the Cetacea the manus is formed into a paddle, being covered by
continuous integument, which conceals all trace of division into
separate digits, and shows no sign of nails or claws. In the Sloths
the manus is long and very narrow, habitually curved, and terminat-
ing in two or three pointed curved claws in close apposition with
each other, and incapable, in fact, of being divaricated ; so that it is
reduced to the condition of a hook, by which the animal suspends
itself to the boughs of the trees among which it lives. These are
only examples of the endless modifications to which the distal
extremity of the limb is subjected in adaptation to the various
purposes to which it is applied.
Posterior Limb. — The posterior limb is constructed upon a plan
very similar to that of the anterior extremity. It consists of a
pelvic girdle and three segments belonging to the limb proper, viz.
the thigh, the leg, and the foot or pes (Fig. 15).
Pelvic Girdle. — The pelvic girdle is present in some form in all
mammals, though in the Cetacea and the Sirenia it is in an exceed-
ingly rudimentary condition. In all mammals except those be-
longing to the two orders just named, each lateral half of the pelvic
girdle consists essentially, like the corresponding part of the anterior
THE SKELETON 51
limb, of a flattened rod of bone crossing the long axis of the trunk,
having an upper or dorsal and a lower or ventral end. The upper
end diverges from that of the opposite side, but the lower end
approaches, and, in most cases, meets it, forming a symphysis,
without the intervention of any bone corresponding to the sternum.
The pelvic girdle differs from the shoulder girdle in being firmly
articulated to the vertebral column, thus giving greater power to
the hinder limb in its function of supporting and propelling the
body. Like the shoulder girdle, it bears on its outer side, near
the middle, a cup-shaped articular cavity (" acetabulum "), into
which the proximal end of the first bone of the limb proper is
received. Each lateral half of the girdle is called the "os
innominatum," or innominate bone, and consists originally of three
bones which unite at the acetabulum. The "ilium" or upper bone
is that which articulates with the sacral vertebrae. Of the two
lower bones the anterior or " pubis " unites with its fellow of
the other side at the symphysis; the posterior is the "ischium."
These lower elements form two bars of bone, united above and
below, but leaving a space between them in the middle, filled only
by membrane, and called the " thyroid " or " obturator " foramen.
The whole circle of bone formed by the two innominate bones
and the sacrum is called the pelvis. In the Monotremata
and Marsupialia, a pair of thin, flat, elongated ossifications
called epipubic or marsupial bones are attached to the fore part
of the pubis, and project forward into the muscular wall of the
abdomen.
Thigh and Leg. — The first segment of the limb proper has one
bone, the femur, corresponding with the humerus of the anterior
limb. The second segment has two bones, the tibia and fibula, corre-
sponding with the radius and ulna. These bones always lie in their
primitive unmodified position, parallel to each other, the tibia on
the preaxial and the fibula on the postaxial side, and are never
either permanently crossed or capable of any considerable amount
of rotation, as in the corresponding bones of the fore limb. In the
ordinary walking position the tibia is internal, and the fibula ex-
ternal. In many mammals the fibula is in a more or less rudi-
mentary condition, and it often ankyloses with the tibia at one or
both extremities. The patella or " knee-cap," which is found in an
ossified condition in all mammals, with the exception of some of
the Marsupialia, is a large sesamoid bone developed in the tendon
of the extensor muscles of the thigh, where the tendon passes over
the front of the knee-joint, to which it serves as a protection.
There are frequently smaller ossicles, one or two in number, situated
behind the femoral condyles, called "fabelke." The processes for
the attachment of muscles near the upper end of the femur are
termed trochanters ; and the third trochanter, found on the hinder
52 GENERAL ANATOMICAL CHARACTERS
aspect of the shaft of this bone in many forms is of considerable
taxonomic importance.
Pes. — The terminal segment of the hind limb is the foot or pes.
Its skeleton presents in many particulars a close resemblance to that
of the manus, being divisible into three parts: (1) a group of
short, more or less rounded or square bones, constituting the
tarsus ; (2) a series of long bones placed side by side, forming the
metatarsus; and (3) the phalanges of the digits or toes.
The bones of the tarsus of many of the lower Vertebrata closely
resemble both in number and arrangement those of the carpus, as
shown in Fig. 1 7. They have been described in their most general-
ised condition by Gegenbaur under the names expressed in the first
column of the following table. The names in the second column are
those by which they are generally known to English anatomists,
while in the third column some synonyms occasionally employed
are added.
Tibialei?) ) =Agt lugl =Talus
Intermedium J
Fibula/re = Calcaneum = Os calcis.
Centrale = Navicular = Scaphoideum.
Tarsale 1 = Internal cuneiform = Entocunciforme.
Tarsale 2 = Middle cuneiform = Mesocuneiforme.
Tarsale 3 = External cuneiform = Ectocuneiforme.
Tarsale 4 \ _ p i • j
Tarsale 5 J
The bones of the tarsus of mammals present fewer diversities of
number and arrangement than those of the carpus. The proximal
row (see Fig. 18) always consists of two bones, namely the astra-
galus (a), which probably represents the coalesced scaphoid and lunar
of the hand, and the calcaneum (c). The former is placed more to
the dorsal side of the foot than the latter, and almost exclusively
furnishes the tarsal part of the tibio-tarsal or ankle-joint. The cal-
caneum, placed more to the ventral or " plantar " side of the foot, is
elongated backwards to form a more or less prominent tuberosity,
the " tuber calcis," to which the tendon of the great extensor muscles
of the foot is attached. The navicular bone (?i) is interposed between
the proximal and distal row on the inner or tibial side of the foot,
but on the outer side the bones of the two rows come into contact.
The distal row, when complete, consists of four bones, which, be-
ginning on the inner side, are the three cuneiform bones, internal
(c 1 ), middle (c 2 ), and external (c 3 ), articulated to the distal surface
of the navicular, and the cuboid (cb), articulated with the calcaneum.
Of these the middle cuneiform is usually the smallest in animals
1 Cope and Baur consider that the astragalus corresponds only with the inter-
medium, and that the tihiale may exist as a distinct element.
THE DIGESTIVE SYSTEM
53
in which all five digits arc developed ; but when the hallux is
wanting the internal cuneiform may be rudimentary or altogether
absent. The three cuneiform bones sup-
port respectively the first, second, and third
metatarsals, and the cuboid supports the
fourth and fifth ; they thus exactly corre-
spond with the four bones of the distal row
of the carpus.
In addition to these constant tarsal
bones, there may be supplemental or
sesamoid bones : one situated near the
middle of the tibial side of the tarsus,
largely developed in many Carnivora and
Rodentia ; another, less frequent, on the
fibular side ; and a third, often developed
in the tendons of the plantar surface of
the tarsus, is especially large in Armadillos.
There is also usually a pair of sesamoid
bones on the plantar aspect of each meta-
tarso-phalangeal articulation. In the young
of the carnivorous genus Cryptoprocta there
may be a second centrale, which usually
coalesces with the ectocuneiform.
The metatarsal bones never exceed five
in number, and the phalanges follow the
same numerical rule as in the manus, never
exceeding three in each digit. Moreover,
the first digit, counting from the tibial side,
or hallux, resembles the pollex of the hand
in always having one segment less than
the other dibits. As the function of the
hind foot is more restricted than that of the hand the modifica-
tions of its structure are less striking. In the Cetacea and the
Sirenia it is entirely wanting, though in some existing members of
the first-named order rudiments of the bones of both the first and
second segments of the limb have been detected, and a femur is
present in the Miocene Sirenian Halitherium.
Fio. 18.— Bones of the right
Human foot. T, Tarsus ; M,
metatarsus ; Ph, phalanges ; c,
calcaneum ; a, astragalus ; cb,
cuboid ; n, navicular ; c 1 , inter-
nal cuneiform ; c-, middle cunei-
form ; c3, external cuneiform. The
digits are indicated by Roman
numerals, counting from the
tibial to the fibular side.
IV. THE DIGESTIVE SYSTEM.
General Considerations. — The search after the purpose which
every modification of structure subserves in the economy is always
full of interest, and, if conducted with due caution and sufficient
knowledge of all the attendant circumstances, may lead to important
generalisations. It must always be borne in mind, however, that
54 GENERAL ANATOMICAL CHARACTERS
adaptation to its special function is not the only cause of the
particular form or structure of an organ, but that this form, having
in all probability been arrived at by the successive and gradual
modification of some other different form from which it is now to a
greater or less degree removed, has other factors besides use to be
taken into account. In no case is this principle so well seen as in
that of the organs of digestion. These may be considered as
machines which have to operate upon alimentary substances in very
different conditions of mechanical and chemical combination, and to
reduce them in every case to the same or precisely similar
materials ; and Ave might well imagine that the apparatus required
to produce flesh and blood out of coarse fibrous vegetable substances
would be different from that which had to produce exactly the
same results out of ready-made flesh or blood ; and in a very broad
sense we find that this is so. Thus, if we take a large number of
carnivorous animals, belonging to different fundamental types, and
a large number of herbivorous animals, and strike a kind of average
of each, we shall find that there is, pervading the first group, a
general style, if we may use the expression, of the alimentary organs,
different from that of the others. That is to say, there is a specially
carnivorous and a specially herbivorous modification of these parts.
But, if function were the only element which has guided such
modification, it might be inferred that, as one form must be supposed
to be best adapted in its relation to a particular kind of diet, that
form would be found in all the animals consuming such diet. But
this is far from being the case. Thus the Horse and the Ox, for
instance — two animals whose food in the natural state is precisely
similar — are most different as regards the structure of their ali-
mentary canal, and the processes involved in the preparation of that
food. Again, the Seal and the Porpoise, both purely fish-eaters,
which seize, swallow, and digest precisely the same kind of prey, in
precisely the same manner, have a totally different arrangement of the
alimentary canal. If the Seal's stomach is adapted in the best conceiv-
able manner for the purpose it has to fulfil, why is not the Porpoise's
stomach an exact facsimile of it, and vice versa ? We can only answer
that the Seal and Porpoise belong to different natural groups of
animals, formed either on different primitive types, or descended
from differently constructed ancestors. On this principle only can
we account for the fact that, whereas, owing to the comparatively
small variety of the different alimentary substances met with in
nature, few modifications would appear necessary in the organs of
digestion, there is really endless variety in the parts devoted to
this purpose.
Mouth. — The digestive apparatus of mammals, as in other ver-
tebrates, consists mainly of a tube with an aperture placed at or
near either extremity of the body, — the oral and the anal orifice, —
THE DIGESTIVE SYSTEM 55
and furnished with muscular walls, the fibres of which are so
arranged as by their regular alternate contraction and relaxation to
(hive onwards the contents of the tube from the first to the second
of these apertures. The anterior or commencing portion of this
tube and the parts around it are greatly and variously modified in
relation to the functions assigned to them of selecting and seizing
the food, and preparing it by various mechanical and chemical
processes for the true digestion which it has afterwards to undergo
before it can be assimilated into the system. For this end the tube
is dilated into a chamber or cavity called the mouth, bordered
externally by the lips, which are usually muscular and prehensile,
and supported by a movable framework carrying the teeth ; the
structure and modifications of which have been already described.
The roof of the mouth is formed by the palate, terminating behind
by a muscular, contractile arch, having in Man and some few other
species a median projection called the uvula, beneath which the
mouth communicates with the pharynx. The anterior part of the
palate is composed of mucous membrane tightly stretched over the
flat or slightly concave bony lamina separating the mouth from
the nasal passages, and is generally raised into a series of trans-
verse ridges, which sometimes, as in Ruminants, attain a con-
siderable development. In the floor of the mouth, between the
rami of the mandible, and supported behind by the hyoidean
apparatus, lies the tongue ; an organ the free surface of which,
especially in its posterior part, is devoted to the sense of taste, but
which also, by its great mobility (being composed almost entirely
of muscular fibres), performs important mechanical functions
connected with masticating and procuring food. Its modifications
of form in different mammals are very numerous. Between the
long, extensile, vermiform tongue of the Anteaters, which is
essential to the peculiar mode of feeding of those animals, and the
short, sessile, and almost functionless tongue of the Porpoise, every
intermediate condition is found. Whatever the form, the upper
surface is always covered with numerous fine papilla?, in which
the terminal filaments of the gustatory nerve are distributed.
Salivary Glands. — The fluid known as the saliva is secreted by
an extensive and complex system of glands discharging into the
cavity of the mouth (buccal cavity), the position and relation of
some of which are exhibited in the woodcut on the next page
(Fig. 19).
This apparatus consists of small glands embedded in the mucous
membrane or submucous tissue lining the cavity of the mouth,
which are of two kinds (the follicular and the racemose), and of
others in which the secreting structure is aggregated in distinct
masses removed some distance from the cavity ; other tissues besides
the lining membrane being usually interposed, and pouring their
56
GENERAL ANATOMICAL CHARACTERS
secretion into the cavity by a distinct tube or duct, which traverses
the mucous membrane. To the latter alone the name of " salivary
glands " is ordinarily appropriated, although the distinction
between them and the smaller racemose glands is only one of
convenience for descriptive purposes, their structure being more or
less nearly identical ; and, since the fluids secreted by all become
mixed in the mouth, their functions are, at all events in great part,
Under the name of salivary glands are commonly
common.
MSP
Fig. 19. — Salivary Glands of the Genet. A, Right side of the head dissected ; p, parotid
gland ; d, Steno's duct ; sm, submaxillary gland, traversed by the jugular veins (jv) ; o, aperture
of Steno's duct. B, Part of the head with the lip drawn up to show (st.d) aperture of
Steno's duct ; z.gl, zygomatic gland ; o, aperture of do. ; z, zygomatic arch. (Mivart, Proo.
Zool. Soc. 1882, p. 504.)
included — (1) the "parotid" (p), situated very superficially on the
side of the head, below or around the cartilaginous external
auditory meatus, and the secretion of which enters the mouth by
a duct (often called Steno's or Stenson's) which crosses the masseter
muscle and opens into the upper and back part of the cheek
(Fig. 19); and (2) the "submaxillary" (sm), situated in the neck,
near or below the angle of the mandible, and sending a long duct
THE DIGESTIVE SYSTEM 57
(Wharton's) forwards to open on the fore-part of the floor of the
cavity of the month, below the apex of the tongue. These are the
most largely developed and constant of the salivary glands, being-
met with in various degrees of development in almost all animals
of the class. Next in constancy are (3) " the sublingual," closely
associated with the last-named, at all events in the locality in which
the secretion is poured out ; and (4) the " zygomatic " (z.gl), found
only in some animals in the cheek, just under cover of the anterior
part of the zygomatic arch, its duct entering the buccal cavity near
that of the parotid.
The most obvious function common to the secretion of these
various glands, and to that of the smaller ones placed in the mucous
membrane of the lips, the cheeks, the tongue, the palate, and fauces,
is the mechanical one of moistening and softening the food, to
enable it the more readily to be tasted, masticated, and swallowed,
though each kind of gland may contribute in different manner
and different degree to perform this function. The saliva is,
moreover, of the greatest importance in the first stage or introduc-
tion to the digestive process, as it dissolves or makes a watery
extract of all soluble substances in the food, and so prepares them
to be further acted on by the more potent digestive fluids met with
subsequently in their progress through the alimentary canal. In
addition to these functions it seems noAv well established by experi-
ment that saliva serves in Man and many animals to aid directly
in the digestive process, particularly by its power of inducing the
saccharine transformation of amylaceous substances. As a general
rule, in mammals the parotid saliva is more watery in its
composition, while that of the submaxillaries, and still more the
sublingual, contains more solid elements and is more viscid ; — so
much so that some anatomists consider the latter, together with the
small racemose glands of the cheeks, lips, and tongue, as mucous
glands, retaining the name of salivary only for the parotid. These
peculiar properties are sometimes illustrated in a remarkable
degree, as, for example, the great secretion of excessively viscid
saliva which lubricates the tongue of the Anteaters and Armadillos,
associated with enormously developed submaxillary glands ; while,
on the other hand, the parotids are of great size in those animals
which habitually masticate dry and fibrous food.
Stomach. — After the preparation which the aliment has under-
gone in the mouth, — the extent of which varies immensely in
different forms, being reduced almost to nothing in such animals as
the Seals and Cetaceans, which, to use the familiar expression,
" bolt " their food entire, and most fully carried out in the Rumin-
ants, Avhich " chew the cud," — it is swallowed, and carried along
the oesophagus by the action of its muscular coats into the stomach.
In the greater number of mammals this organ is a simple saccular
58
GENERAL ANATOMICAL CHARACTERS
dilatation of the alimentary canal, as in Figs. 20, 21, but in others
it undergoes remarkable modifications and complexities. The lining
of the stomach is thickly beset with tubular glands, which are
generally considered to belong to two different forms, recognisable
by their structure, and different in their function — the most
numerous and important secreting the gastric juice (the active
agent in stomachic digestion), and hence called " peptic " glands,
while the others are concerned only in the elaboration of mucus.
The relative distribution of these glands in different regions of the
Avails of the stomach varies greatly in different animals, and in
many species there are large tracts of the mucous membrane which
do not secrete a fluid having the properties of gastric juice, but
often constitute more or less distinct cavities devoted to storing
Fig. 20. — Stomach and pancreas of the Genet. Posterior or dorsal surface, a', (Esophagus ;
s, pancreas ; pd, pancreatic duct ; bd, biliary duct from the liver. (From Mivart, Proc. Zool.
Soc. 1882, p. 305.)
and perhaps softening or otherwise preparing the food for digestion.
Sometimes there is a great aggregation of glands forming distinct
thickened patches of the stomach wall, as in the Beaver and Koala,
or even collected in pyriform pouches with a common narrow
opening into the cavity, as in the Manatee and the curious African
Rodent Lophiomi/s. The action of the gastric fluid is mainly
exerted upon the nitrogenous elements of the food, which it
dissolves and modifies so as to render them capable of undergoing
absorption, effected partly by the blood-vessels of the stomach,
although the greater part passes through the pylorus, an aperture
surrounded by a circular muscular valve, into the intestinal canal.
Here it comes in contact with the secretion of a vast number of
small glands called the crypts of Lieberkuhn, somewhat similar
to those of the stomach ; and also of several special glands of a
different character, namely, the small racemose, duodenal, or
THE DIGESTIVE SYSTEM
59
Brunner's glands, the pancreas, and the liver ; the position of the
ducts of the two latter organs being indicated in Fig. 20.
Intestinal Canal. — The intestinal canal varies greatly in relative
length and capacity in different animals, and it also offers manifold
peculiarities of form, being sometimes a simple cylindrical tube of
nearly uniform calibre throughout, but more often subject to altera-
tions of form and capacity in different portions of its course, — the
most characteristic and constant being the division into an upper
and narrower, and lower and wider portion, called respectively the
small and the large intestine, the former being divided quite arbi-
trarily and artificially into duodenum, jejun-
um, and ileum, and the latter into colon and
rectum. One of the most striking peculiari-
ties of this part of the alimentary canal is
the frequent presence of a diverticulum or
blind pouch, the caput ccecurn coli, as it was
first called, a name generally abbreviated into
" caecum," situated at the junction of the
large and the small intestine, a structure pre-
senting an immense variety of development,
from the smallest bulging of a portion of the
side wall of the tube to a huge and complex
sac, greatly exceeding in capacity the whole
of the remainder of the alimentary canal. It
is only in herbivorous animals that the caecum
is developed to this great extent, and among
these there is a curious complementary re-
,,.,., ,, . x , i ■, Fig- 21. — Diagrammatic
lationship between the size and complexity plan of the gen erai arrange-
Of this Organ and that of the Stomach, ment of the alimentary canal
Where the latter is simple the caecum is * a *>'P ical / I f nmal - °-
r CEsophagus ; st, stomach ; p,
generally the largest, and vice versa. Both the py i rus ; s, s, small intestine
caecum and colon are often sacculated, a dis- (abbreviated) ; e, caecum ; i, i,
position caused by the arrangement of the Jjj^^^Sj rectum? 1011 ' "*"
longitudinal bands of muscular tissue in their
vails ; but the small intestine is always smooth and simple-walled
externally, though its lining membrane often exhibits various
contrivances for increasing the absorbing surface "without adding to
the general bulk of the organ, such as the numerous small villi by
which it is everywhere beset, and the more obvious transverse,
longitudinal, or reticulating folds projecting into the interior, met
with in many animals, of Avhich the " valvulae conniventes " of Man
form well-known examples. ,
Besides the crypts of Lieberkuhn found throughout the in-
testinal canal, and the glands of Brunner confined to the duodenum,
there are other structures in the mucous membrane, about the
nature of which there is still much uncertainty, called " solitary " and
60 GENERAL ANATOMICAL CHARACTER
" agminated " glands ; the latter being more commonly known by the
name of "Peyer's patches." These were formerly supposed to be
secretory organs, which discharged some kind of fluid into the
intestine, but are now more generally considered to belong to that
group of structures of somewhat mysterious function of which the
lymphatic and lacteal glands are members. The solitary glands are
found scattered irregularly throughout the whole intestinal tract ;
the agminated, on the other hand, are always confined to the small
intestine, and are most abundant in its lower part. They are
subject to great variation in number and in size, and even
in different individuals of the same species, and also differ in
character at different periods of life, becoming atrophied in old
age.
Liver. — The distinct glands situated outside the walls of the
intestinal canal, but which pour their secretion into it, are the
pancreas and the liver. The latter is the more important on
account of its size, if not on account of the direct action of its
secretion in the digestive process. This large gland, so complex in
structure and function, is well developed in all mammals, and its
secreting tube, the bile-duct, always opens into the duodenum, or
that portion of the canal which immediately succeeds the stomach.
It is situated on the riskt side of the abdomen in contact with the
diaphragm and the stomach, but varies greatly in relative size, and
also in form, in different groups of mammals. In most mammals a
gall-bladder, consisting of a pyriform diverticulum from the bile-
duct, is present, but in many this appendage is wanting, and it is
difficult to find the rationale of its presence or absence in relation
to use or any other circumstance in the animal economy.
The descriptions of the livers of various animals to be met
with in treatises or memoirs on comparative anatomy are very
difficult to understand for want of a uniform system of nomencla-
ture. The difficulty usually met with arises from the circumstance
that this organ is divided sometimes, as in Man, Ruminants, and
the Cetacea, into two main lobes, which have been always called
respectively right and left, and in other cases, as in the lower
Monkeys, Carnivora, Insectivora, and several other orders, into a
larger number of lobes. Among the latter the primary division usu-
ally appears at first sight tripartite, the whole organ consisting of a
middle, called " cystic " or " suspensory " lobe, and two lateral lobes,
called respectively right and left lobes. This introduces confusion
in describing livers by the same terms throughout the whole series
of mammals, since the right and left lobes of the Monkey or Dog,
for instance, do not correspond Avith parts designated by the same
names in Man and the Sheep. There are, moreover, conditions
where neither the bipartite nor the tripartite system of nomencla-
ture will answer, so that we should have considerable difficulty in
THE DIGESTIVE SYSTEM
61
describing them without some more general system. In order to
arrive at such a system it appears desirable to consider the liver in
all cases as primarily divided by the umbilical vein (see Fig. 22, u)
into two segments, right and left. This corresponds with its
development and with the condition characteristic of the organ in
the inferior classes of vertebrates. The situation of this division
can almost always be recognised in adult animals by the persistence
of some traces of the umbilical vein in the form of the round
ligament, and by the position of the suspensory ligament.
When the two main parts into Avhich the liver is thus divided
are entire, as in Man, the Ruminants, and Cetacea, they may be
spoken of as the right and left lobes ; when fissured, as the right
and left segments of the liver, reserving the term lobe for the sub-
Fig. 22. — Diagrammatic plan of the inferior surface of a multilobed liver of a Mammal.
The posterior or attached border is uppermost, u, Umbilical vein of the fcetus, represented by
the round ligament in the adult, lying in the umbilical fissure ; dv, the ductus venosus ; vc,
the inferior vena cava ; p, the vena portas entering the transverse fissure ; llf, the left lateral
fissure ; rlf, the right lateral fissure ; c/, the cystic fissure ; 11, the left lateral lobe ; Ic, the left
central lobe ; re, the right central lobe ; rl, the right lateral lobe ; s, the Spigelian lobe ; c, the
caudate lobe ; g, the gall-bladder.
divisions. This will involve no ambiguity, for the terms right and
left lobe will no longer be used for divisions of the more complex
form of liver. In the large majority of mammals each segment is
further divided by a fissure, more or less deep, extending from
the free towards the attached border, which are called right and
left lateral fissures (Fig. 22, rlf and llf). When these are more
deeply cut than the umbilical fissure (u), the organ has that
tripartite or trefoihlike form just spoken of, but it is easily seen
that it is really divided into four regions or lobes, those included
between the lateral fissures being the right and left central (re and
Ic) separated by the umbilical fissure, and those beyond the lateral
fissures on each side being the right and left lateral lobes (rl and 11).
62 GENERAL ANATOMICAL CHARACTERS
The essentially bipartite character of the organ and its uniformity
of construction throughout the class are thus not lost sight of, even
in the most complex forms. The left segment of the liver is rarely
complicated to any further extent, except in some cases by minor
or secondary fissures marking off small lobules, generally inconstant
and irregular, and never worthy of any special designation. On
the other hand, the right segment is usually more complex. The
gall-bladder, when present, is always attached to the under surface
of the right central lobe, sometimes merely applied to it, in other
cases deeply embedded in its substance. In many instances the
fossa in which it is sunk is continued to the free margin of the
liver as an indent, or even a tolerably deep fissure (cf). The
portal fissure (p), through which the portal vein and hepatic artery
enter and the bile-duct emerges from the liver, crosses the right
central lobe transversely, near the attached border of the liver.
The right lateral lobe always has the great vena cava (yc) either
grooving its surface or tunnelling through its substance near the
inner or left end of its attached border ; and a prolongation of this
lobe to the left, between the vein and the portal fissure, sometimes
forming a mere flat track of hepatic substance, but more often
a prominent tongue-shaped process, is the so-called "Spigelian lobe"
(s). From the under surface of the right lateral lobe a portion is
generally partially detached by a fissure, and called the " caudate
lobe " (c). In Man this lobe is almost obsolete, but in most
mammals it is of considerable magnitude, and has very constant
and characteristic relations. It is connected by an isthmus at the
left (narrowest or attached) end to the Spigelian lobe, behind which
isthmus the vena cava is always in relation to it, channelling
through or grooving its surface. It generally has a pointed apex,
and is deeply hollowed to receive the right kidney, to the upper
and inner side of which it is applied.
Considerations derived from the comparatively small and simple
condition of the liver of the Ungulata, compared with its large
size and complex form in the Carnivora, have led to the perhaps
too hasty generalisation that the first type is related to a herbivorous
and the latter to a carnivorous diet. The exceptions to such a
proposition are very numerous. The fact of the great difference
between the liver of the Cetacea and that of the Seals cannot
be accounted for by difference of habits of life, though it perhaps
may be by difference of origin. 1
1 For further details of these modifications, see Flower's "Lectures on the
Comparative Anatomy of the Organs of Digestion of the Mammalia," Medical
Times and Gazette, Feb. -Dec. 1872.
CIRCULATORY AND RESPIRATORY SYSTEMS 63
V. CIRCULATORY, ABSORBENT, RESPIRATORY, AND URINARY
SYSTEMS.
Blood. — The blood of mammals is always red, and during the
life of the animal hot, having a nearly uniform temperature,
varying within a few degrees on each side of 100° Fahr. The
corpuscles are, as usual in the vertebrates, of two kinds : ( 1 )
colourless, spheroidal, nucleated, and exhibiting amoeboid move-
ments ; while (2) the more numerous, on which depends the
characteristic hue of the fluid in which they are suspended, are
coloured, non -nucleated, flattened, slightly biconcave discs, Avith
circular outline in all known species except the Camels and Llamas,
where they have the elliptical form characteristic of the red
corpuscles of nearly all the other vertebrates, though adhering to
the mammalian type in the absence of nucleus and relatively small
size. As a rule they are smaller as well as more numerous than in
other classes, but vary considerably in size in different species, and
not always in relation to the magnitude of the animal ; a Mouse,
for instance, having as large corpuscles as a Horse. Within the
limits of any natural group there is, however, very often some such
relation, the largest corpuscles being found among the large species
and the smallest corpuscles among the small species of the group,
but even to this generalisation there are many exceptions. The
transverse diameter of the red corpuscles in Man averages -32V0 of
an inch, which is exceptionally large, and only exceeded by the
Elephant { z fa s ), and by some Cetacea and Edentata. They are
also generally large in Apes, Rodents, and the Monotremata, and
small in the Artiodactyles, least of all in the Chevrotains (Tragulus),
being in T. javanicus and meminna not more than x^stts- 1
Heart. — The heart of mammals consists of four distinct cavities,
two auricles and two ventricles. Usually the ventricular portion is
externally of conical form, with a simple apex, but in the Sirenia it
is broad and flattened, and a deep notch separates the apical portion
of each ventricle. A tendency to this form is seen in the Cetacea
and the Seals. It is characteristic of mammals alone among verte-
brates that the right auriculo-ventricular valve is tendinous like the
left, consisting of flaps held in their place by fibrous ends (chordce
tendinice) and arising from projections of the muscular walls of
the ventricular cavity (riiusculi papUlares). In the Monotremata a
transition between this condition and the simple muscular flap of
the Sauropsida is observed. In most of the larger Ungulates a dis-
tinct but rather irregular ossification (os cordis) is developed in the
central tendinous portion of the base of the heart.
Blood-vessels. — The orifices of the aorta and pulmonary artery are
1 G. Gulliver, Proc. Zool. Soc., 1862, p. 91.
64 GENERAL ANATOMICAL CHARACTERS
each guarded by three semilunar valves. The aorta is single, and
arches over the left bronchial tube. After supplying the tissues of
the heart itself with blood by means of the coronary arteries, it
gives off large vessels ("carotid") to the head and ("brachial") to the
anterior extremities. The mode in which these vessels arise from
the aorta varies much in different mammals, and the study of their
disposition affords some guide to classification. In nearly all cases
the right brachial and carotid have a common origin (called the
"innominate artery" in anthropotomy). The other two vessels
may come off from this, as is the rule in Ungidates, the common
trunk constituting the " anterior aorta " of veterinary anatomy ; or
they may be detached in various degrees, both arising separately
from the aorta, as in Man, or the left carotid from the innominate
and the left brachial from the aorta, a very common arrangement ;
or the last two from a common second or left innominate, as in
some Bats and Insectivores. The aorta, after giving off the inter-
costal arteries, passes through the diaphragm into the abdomen, and,
after supplying the viscera of that cavity by means of the gastric,
hepatic, splenic, mesenteric, renal, and spermatic vessels, gives off
in the lumbar region a large branch (iliac) to each of the hinder
extremities, which also supplies the pelvic viscera, and is continued
onwards in the middle line, greatly diminished in size, along the
under surface of the tail as the caudal artery. In certain mammals,
arterial plexuses, called retia mirabilia, formed by the breaking up
of the vessel into an immense number of small trunks, which may
run in a straight course parallel to one another (as in the limbs of
►Sloths and Slow Lemurs), or form a closely packed network, as in
the intracranial plexuses of Ruminants, or a sponge-like mass of
convoluted vessels, as in the intercostals of Cetaceans, are
peculiarities of the vascular system the meaning of which is
not in all cases clearly understood. In the Cetacea they are ob-
viously receptacles for containing a large quantity of oxygenated
blood available during the prolonged immersion, with consequent
absence of respiration, to which these animals are subject.
The vessels returning the blood to the heart from the head and
upper extremities usually unite, as in Man, to form the single vena
cava superior or precaval vein, but in some Insectivores, Chiroptera,
and Rodents, in the Elephant, and all Marsupials and Monotremes,
the two superior caval veins enter the right auricle without uniting,
as in birds. In Seals and some other diving mammals there is a
large venous sinus or dilatation of the inferior vena cava immediately
below the diaphragm. In the Cetacea the purpose of this is supplied
by the immense abdominal venous plexuses. As a rule the veins
of mammals are furnished with valves, but these are said to be
altogether wanting in the Cetacea, and in the superior and inferior
cava, subclavian and iliac veins, the veins of the liver (both portal
ABSORBENT SYSTEM 65
and hepatic), heart, lungs, kidneys, brain, and spinal cord of other
mammals. Many of the veins within the cranium are included in
spaces formed by the separation of the laminae of the dura mater,
and do not admit of being dilated beyond a certain size ; these are
termed sinuses. The portal circulation in mammals is limited to
the liver, the portal vein being formed by the superior and inferior
mesenteric, the splenic, the gastroepiploic, and the pancreatic veins.
The kidney is supplied solely by arterial blood, and its veins empty
their contents only into the inferior cava.
Lymphatic Fessels.—The absorbent or lymphatic system of vessels is
very fully developed in the Mammalia. Its ramifications extend
through all the soft tissues of the body, and convey a colourless
fluid called lymph, containing nucleated corpuscles, and also,
during the process of digestion, the chyle, a milky fluid taken up
by the lymphatics (here called lacteals) of the small intestine, and
pour them into the general vascular system, where they mix with
the venous blood. The lymphatic vessels of the hinder extremities,
as well as those from the intestinal canal, unite in the abdomen to
form the "thoracic duct," the hinder end or commencement of
which has a dilatation called the receptacvlum chyli. This duct,
which is of irregidar size and sometimes double, often dividing and
uniting again in its course, or even becoming plexiform, passes for-
wards close to the bodies of the thoracic vertebrae, and empties itself,
by an orifice guarded by a valve, into the great left brachio-cephalic
vein, having previously received the lymphatics from the thorax and
the left side of the head and left anterior extremity. The lymph-
atics from the right side of the head and right anterior limb usually
enter by a small distinct trunk into the corresponding part of the
right brachio-cephalic vein. The duct, and also the principal lymph-
atic vessels, are provided with valves.
Lymphatic glands, rarely met with in the Sauropsida, are usually
present in mammals, both in the general and in the lacteal system ;
the latter being called " mesenteric glands." They are round or oval
masses, situated upon the course of the vessels, which break up in
them and assume a plexiform arrangement, and then reunite
as they emerge. No structures corresponding to the pulsating
" lymphatic hearts " of the lower vertebrates have been met with in
mammals.
Ductless Glands. — Associated with the vascular and lymphatic
systems are certain bodies (the functions of which are not properly
understood), usually, on account of their general appearance,
grouped together under the name of "ductless glands." The
largest of these is the " spleen," which is single, and always
placed in mammals in relation to the fundus or left end of the
stomach, to which it is attached by a fold of peritoneum. It is dark-
coloured and spongy in substance, and has a depression or " hilus "
5
66 GENERAL ANATOMICAL CHARACTERS
on one side, into which the splenic artery, a branch of the coeliac
axis of the abdominal aorta, enters, and from which the vein joining
the portal system emerges. The spleen varies much in size and form
in different mammals, being relatively very small in the Cetacea.
It is sometimes almost spherical, but more often flattened, oval,
triangular, or elongated, and occasionally, as in Monotremes and
most Marsupials, triradiate. The "suprarenal bodies" or "adrenals"
are two in number, each situated either in contact with, or at a
short distance in front of the anterior extremity of the kidney.
They are abundantly supplied with nerves, and are much larger re-
latively in early than in adult life. The "thyroid bodies," of which
there are generally two, though in Man and some other species
they are connected by an isthmus passing across the middle line,
are constant in mammals, though only met with in a rudimentary
condition, if at all, in other vertebrates. They are situated in the
neck, in contact with the sides of the anterior extremity of the
trachea. The " thymus " lies in the anterior part of the thorax,
between the sternum and the great vessels at the base of the heart,
and differs from the thyroid in being median and single, and having
a central cavity. It attains its greatest development during the
period in which the animal is nourished by its mother's milk, and
then it diminishes, and generally disappears before full growth is
attained.
Nostrils. — Mammals breathe occasionally through the mouth,
but usually, and in many cases exclusively, through the nostrils or
tmres. These are apertures, always paired (except in the toothed
Cetacea, where they unite to form a single external opening), and
situated at the fore part of the face, generally at or beneath the
end of the muzzle, a median prominence above the mouth. This is
sometimes elongated to form a proboscis, to the extremity of which
the nostrils are carried, and which attains its maximum of develop-
ment in the Elephant. In the Cetacea the nostrils are situated at
a considerable distance behind the anterior end of the face, upon
the highest part of the head, and are called " blow-holes," from the
peculiar mode of respiration of those animals. The nostrils are
kept open by means of cartilages surrounding their aperture,
which many animals have the power of moving so as to cause
partial dilatation or contraction. In diving animals, as Seals and
Cetacea, they can be completely closed at will so as to prevent the
entrance of water when beneath the surface. The passage to which
the nostrils lead is in most mammals filled by a more or less
complex sieve -like apparatus, formed of the convoluted turbinal
bones and cartilages, over which a moist, vascular, ciliated mucous
membrane is spread, which intercepts particles of dust, and also
aids in warming the inspired air before it reaches the lungs. In
the Proboscidea, in which these functions are performed by
RESPIRATORY SYSTEM 67
the walls of the long tubular proboscis, this apparatus is entirely
wanting.
Trachea. — The narial passages have the organ of smell situated
in their upper part, and communicate posteriorly with the
pharynx, and through the glottis Math the " trachea " or windpipe,
a tube by which the air is conveyed to and from the lungs. The
permanent patency of the trachea during the varied movements of
the neck is provided for by its walls being stiffened by a series of
cartilaginous rings or hoops, which in most mammals are incomplete
behind. Having entered the thorax, the trachea bifurcates into the
two bronchi, one of which enters, and, dividing dichotomously,
ramifies through each lung. In some of the Cetacea and
Artiodactyla a third bronchus is given off from the lower
part of the trachea, above its bifurcation, and enters the right
lung.
Larynx. — The upper end of the trachea is modified into the
organ of voice or " larynx," the air passing through which to and
from the lungs is made use of to set the edges of the " vocal cords,"
or fibrous bands stretched one on each side of the tube, into vibra-
tion. The larynx is composed of several cartilages, stich as the
"thyroid," the "cricoid," and the " arytenoid " which are moved
upon one another by muscles, and suspended from the hyoidean arch.
By alteration of the relative position of these cartilages the cords
can be tightened or relaxed, approximated or divaricated, as
required to modulate the tone and volume of the voice. A median
tongue-shaped fibro-cartilage at the top of the larynx, the "epiglottis,"
protects the " glottis," or aperture by which the larynx communi-
cates with the pharynx, from the entry of particles of food during
deglutition. The form of the larynx and development of the vocal
cords present many variations in different members of the class,
the greatest modification from the ordinary type being met with in
the Cetacea, where the arytenoid cartilages and epiglottis are united
in a tubular manner, so as to project into the nasal passage, and,
being grasped by the muscular posterior margin of the palate, pro-
vide a direct channel of communication from the lungs to the
external surface. An approach to this condition is met with in the
Hippopotamus and some other Ungulates; it is indeed so general
as an abnormality, that Howes suggests that an internarial epi-
glottis may have been a primitive feature common throughout the
class. Nearly all mammals have a voice, although sometimes it is
only exercised at seasons of sexual excitement. Some Marsupials
and Edentates appear to be quite mute. In no mammal is there
an inferior larynx, or " syrinx," as in birds.
Diaphragm. — The thoracic cavity of mammals differs from that
of the Sauropsida in being completely separated from the abdomen
by a muscular partition, the " diaphragm," attached to the vertebral
68 GENERAL ANATOMICAL CHARACTERS
column, the ribs, and the sternum. This is much arched, with the
convexity towards the thorax, so that when its fibres contract and
it is flattened the cavity of the thorax is increased, and when they
are relaxed the cavity is diminished.
Lungs. — The lungs are suspended freely in the thorax, one on
each side of the heart, being attached only by the root, which
consists of the bronchus or air-tube and pulmonary arteries and
veins by which the blood is passed backwards and forwards between
the heart and the lungs. The remaining part of the surface of
each lung is covered by serous membrane, the "pleura"; and what-
ever the state of distension or contraction of the chest-wall, is
accurately in contact with it. Inspiration is effected by the con-
traction of the diaphragm and by the intercostal and other muscles
elevating or bringing forward the ribs, and thus throwing the
sternum farther away from the vertebral column. As the surface
of the lung must follow the chest-wall, the organ itself is expanded,
and air rushes in through the trachea to fill all the minute cells in
which the ultimate ramifications of the bronchi terminate. In
ordinary expiration very little muscular power is expended, the
elasticity of the lungs and surrounding parts being sufficient to
cause a state of contraction and thus drive out at least a portion of
the air contained in the cells, when the muscular stimulus is with-
drawn. The lungs are sometimes simple externally, as in the
Sirenia (where they are greatly elongated) and the Cetacea, but are
more often divided by deep fissures into one or more lobes. The
right lung is usually larger and more subdivided than the left. It
often has a small distinct lobe behind, wanting on the left side, and
hence called lobulus azygos.
Air-sacs. — Most mammals have in connection with the air passages
certain diverticuli or pouches containing air, the use of which is
not always easy to divine. The numerous air sinuses situated
between the outer and inner tables of the bones of the head,
represented in Man by the antrum of Highmore and the frontal and
sphenoidal sinuses, and attaining their maximum of development
in the Indian Elephant, are obviously for the mechanical purpose
of allowing expansion of the osseous surface without increase of
weight. They are connected with the nasal passages. The Eusta-
chian tubes pass from the back of the pharynx to the cavity of the
tympanum, into which and the mastoid cells they allow air to pass.
In the Equiclce there are large post-pharyngeal air-sacs in connection
with them. The Dolphins have an exceedingly complicated system
of air-sacs in connection with the nasal passages just within the
nostrils, and the Tapirs, Rhinoceroses, and Horses have blind sacs
in the same situation. In the males of some Seals (Cystophora and
Macrorhinus) large pouches, which the animal can inflate with air,
and which are not developed in the young animal or the female,
URIXARY SYSTEM 69
arise from the upper part of the nasal passages, and lie immediately
under the skin of the face. These appear analogous, although not
in the same situation, to the gular pouch of the male Bustard.
The larynx frequently has membranous pouches in connection
with it, into which air passes. These may be lateral and opening
just above the vocal cords, when they constitute the saccull laryngis,
found in a rudimentary state in Man, and attaining an enormous
development, so as to reach to the shoulders and axilla?, in some
of the Anthropoid Apes ; or they may be median, opening in
front either above or below the thyroid and cricoid cartilages, as in
the Howling and other Monkeys, and also in the Whalebone
Whales and Great Anteater.
Urinary Organs. — The kidneys of mammals are more compact
and definite in form than in other vertebrates, being usually more
or less oval, with an indent on the side turned towards the middle
line, from and into which the vessels and ducts pass. They are
distinctly divided into a cortical secretory portion, composed
mainly of convoluted tubes, and containing the so-called Malpighian
bodies ; and a medullary excreting portion, formed of straight tubes
converging towards a papilla, embraced by the commencement of
the ureter or duct of the organ. The kidneys of some mammals,
as most Monkeys, Carnivores, Rodents, etc., are simple, with a
single papilla into which all the renal tubuli enter. In others, as
Man, there are many pyramids of the medullary portion, each with
its papilla, opening into a division (calyx) of the upper end of the
ureter. Such kidneys, either in the embryonic condition only, or
throughout life, are lobulated on the surface. In some cases, as in
Bears, Seals, and especially the Cetacea, the lobulation is carried
further, the whole organ being composed of a mass of renules,
loosely united by connective tissue, and with separate ducts, which
soon join to form the common ureter.
Bladder. — In all mammals except the Monotremes the ureters
terminate by slit-like valvular openings in the urinary bladder.
This receptacle when filled discharges its contents through the
single median urethra, which in the male is almost invariably
included in the penis, and in the females of some species of Rodents,
Insectivores, and Lemurs has a similar relation to the clitoris. In
the Monotremes, though the bladder is present, the ureters do not
enter into it, but join the urino-genital canal some distance below
it, with the orifice of the genital duct intervening.
VI. NERVOUS SVSTEM AND ORGANS OF SENSE.
Brain. — The brain of mammals shows a higher condition of
organisation than that of other vertebrates. The cerebral hemi-
70 GENERAL ANATOMICAL CHARACTERS
spheres have a greater preponderance compared with other parts,
especially to the so-called optic lobes, or corpora quadrigemina,
which are completely concealed by them. The commissural system
of the hemispheres is much more complex, both fornix and corpus
callosum being present in some form ; and when the latter is
rudimentary, as in Marsupials and Monotremes, its deficiency is
made up for by the great size of the anterior commissure. The
lateral lobes of the cerebellum, wanting in loAver vertebrates, are
well developed and connected by a transverse commissure, the pons
Varolii. The whole brain, owing especially to the size of the
cerebral hemispheres, is considerably larger relatively to the bulk
of the animal than in other classes, but it must be recollected that
the size of its brain depends upon many circumstances besides the
degree of intelligence which an animal possesses, although this is
certainly one. Man's brain is many times larger than that of all
other known mammals of equal bulk, and even three times as large
as that of the most nearly allied Ape. Equal bulk of body is here
mentioned, because, in drawing any conclusions from the size of
the brain compared with that of the entire animal, it is always
necessary to take into consideration the fact that in every natural
group of closely allied animals the larger species have much smaller
brains relatively to their general size than the smaller species, so
that, in making any effective comparison among animals belonging
to different groups, species of the same size must be selected. It
may be true that the brain of a Mouse is, as compared with the
size of its body, larger than that of a Man, but, if it were possible
to reduce an animal having the general organisation of a Man to the
size of a Mouse, its brain would doubtless be very many times larger ;
and conversely, as shown by the rapid diminution of the relative
size of the brain in all the large members of the Kodent order, a
Mouse magnified to the size of a Man would, if the general rule
were observed, have a brain exceedingly inferior in volume. Al-
though the brain of the large species of Whales is, as commonly
stated, the smallest in proportion to the bulk of the animal of any
mammal, this does not invalidate the general proposition that the
Cetacea have very large brains compared with terrestrial mammals,
like the Ungulata, or even the aquatic Sirenia, as may be proved
by placing the brain of a Dolphin by the side of that of a Sheep, a
Pig, or a Manatee of equal general weight. It is only because the
universally observed difference between the slower ratio of increase
of the brain compared with that of the body becomes so enormous
in these immense creatures that they are accredited with small
brains.
The presence or absence of " sulci " or fissures on the surface
of the hemisphere, dividing it into " convolutions " or " gyri," and
thus increasing the superficies of the cortical gray matter, as well
AEE VO US S 1 r J> TEM
7i
as allowing the pia mater with its nutrient blood-vessels to pene-
trate into the cerebral substance, follow somewhat similar rules.
The sulci are related partly to the high or low condition of organis-
a great degree to the size of
tlie
ation of the species, but also in
cerebral hemispheres. In
very small species of all
groups, even the Primates,
they are absent, and in the
largest species of groups so
low in the scale as the Mar-
supials and Edentates they
are found. They reach their
maximum of development in
the Cetacea.
The accompanying wood-
cut (Fig. 23) shows the prin-
cipal parts of a mammalian
brain, as seen from the
superior, lateral, and inner
surfaces. The sylvian fissure
(>;/) is one of the most con-
stant of the sulci found in
the hemispheres.
The researches of Palae-
ontologists, founded upon
studies of casts of the in-
terior of the cranial cavity
of extinct forms, have shown
that, in many natural groups
of mammals, if not in all,
the brain has increased in
size, and also in complexity
of surface foldings, with the
advance of time, — indicating
in this, as in so many other
respects, a gradual progress
from a lower to a higher type
of development.
Nerves. — The twelve pairs of cranial nerves generally recognised
in vertebrates are usually all found in mammals, though the
olfactory nerves are excessively rudimentary, if not altogether
absent, in the Toothed Whales. The spinal cord, or continuation
of the central nervous axis, lies in the canal formed by the neural
arches of the vertebra?, and gives off the compound double-rooted
nerves of the trunk and the extremities, corresponding in number
to the vertebrae, through the interspaces between which they pass
Fig. 23. — Brain of the Genet (Genetta tigrlna). A,
From above ; B, from the right side ; C, inner sur-
face of right hemisphere ; cc, corpus callosum ;
c.m.s, calloso-marginal sulcus ; c, notch represent-
ing crucial sulcus of other forms ; d, depression on
superior lateral gyrus of hemisphere ; hg, hippo-
cam pal gyrus ; i, inferior lateral gyrus of hemi-
sphere ; m, middle lateral gyrus of do. ; s, superior
lateral gyrus of do. ; os, supraorbital sulcus of do. ;
sf, sylvian fissure of do. ; 61, olfactory lobes. The
deeply convoluted part behind the cerebral hemi-
sphere is the cerebellum, below which lies the
medulla oblongata, or commencement of the spinal
cord. (Mivart, Proc. Zool. Soc. 1882, p. 516.)
72 GENERAL ANATOMICAL CHARACTERS
out to their destination. The cord is somewhat enlarged at the two
points where it gives off the great nerves to the anterior and the
posterior extremities, which, from their interlacements soon after
their origin, are called respectively the brachial and lumbar plexuses.
The ganglionic or sympathetic portion of the nervous system is well
developed, and presents few modifications.
Sense of Touch. — The sense of touch is situated in the skin
generally, but is most acute in certain regions more or less
specialised for the purpose by the presence of tactile papilla?, such
as portions of the face, especially the lips and end of the snout, and
the extremities of the limbs when these are used for other purposes
than mere progression, and the under surface of the end of the tail
in some Monkeys. The " vibrissa? " or long stiff bristles situated
on the face of many mammals are rendered extremely sensitive to
touch by the abundant supply of branches from the fifth nerve to
their basal papilla?. In Bats the extended wing membranes, and
probably also the large ears and the folds and prominences of skin
about the face of some species, are so sensitive as to receive
impressions even from the different degrees of resistance of the air,
and so enable the animals to avoid coming in contact with obstacles
to their nocturnal flight.
Taste and Smell. — The organs of the other special senses are
confined to the head. Taste is situated in the papilla? scattered on
the dorsal surface of the tongue. The organ of smell is present in
all mammals except the Toothed "Whales. It consists of a ramifica-
tion of the olfactory nerves over a plicated, moist, mucous
membrane, supported by folded plates of bone, placed on each side
of the septum nasi in the roof, or often in a partially distinct upper
chamber, of the nasal passage, so arranged that, of the air passing
into the lungs in inspiration, some comes in contact with it, causing
the perception of any odorous particles with which it may be
charged. Many mammals possess intense powers of smelling
certain odours which others are quite unable to appreciate, and the
influence which this sense exercises over the well-being of many
species is very great, especially in indicating the proximity of others
of the same kind, and giving warning of the approach of enemies.
The development and modification of the sense of smell is probably
associated with that of the odorous secretion of the cutaneous
glands.
Sight. — The organ of sight is quite rudimentary, and even
concealed beneath the integument, in some burrowing Rodents and
Insectivores, and is most imperfectly developed in the Platanista, or
Freshwater Dolphin of the rivers of India. In all other mammals
the eyeball has the structure characteristic of the organ in the
higher Vertebrata, consisting of parts through which the rays of
light are admitted, regulated, and concentrated upon the sensitive
ORGANS OF SENSE 73
expansion of the optic nerve lining the posterior part of the ball.
A portion of the fibro-vascular and highly pigmented layer, the
choroid, which is interposed between the retina and the outer
sclerotic coat, is in many mammals modified into a brilliantly-
coloured light-reflecting surface, the tapetum lucidum. There is
never a pecten or marsupium like that of the Sauropsida, nor is
the sclerotic ever supported by a ring of flattened ossicles, as is so
frequently the case in the lower vertebrated classes. The eyeball
is moved in various directions by a series of muscles — the four
straight, two oblique, and, except in the higher Primates, a pos-
terior retractor muscle called choanoid. The superior oblique muscle
passes through a tendinous pulley fastened to the roof of the orbit,
which is a feature not found beyond the limits of the mammalian
class. The eye is protected by the lids, generally distinctly separated
into an upper and a lower movable flap, which, when closed, meet
over the front of the eye in a more or less nearly horizontal line ;
but sometimes, as in the Sirenia, the lids are not distinct, and the
aperture is circular, closing to a point. In almost all mammals
below the Primates, except the Cetacea, a " nictitating membrane "
or third eyelid is placed at the inner corner of the eyeball, and
works horizontally across the front of the ball within the true lids.
Its action is instantaneous, being apparently for the purpose of
cleaning the front of the transparent cornea ; — a function unneces-
sary in animals whose eyes are habitually bathed in water, and which
in Man and his nearest allies is perforaied by winking the true
eyelids. Except in Cetacea the surface of the eye is kept moist by
the secretion of the lachrymal gland, placed under the upper lid at
its outer side, and the lids are lubricated by the Harderian and
Meibomian glands, the former being situated at the inner side of
the orbit, and especially related to the nictitating membrane, the
latter in the lining membrane of the lids.
Hearing. — The organ of hearing is inclosed in a bony capsule
(periotic) situated in the side of the head, intercalated between the
posterior (occipital) and the penultimate (parietal) segment of the
skull. It has, in common with other vertebrates, three semicircular
canals and a vestibule, but the cochlea is more fully developed than
in the Sauropsida, and, except in the Monotremes, spirally con-
voluted. The tympanic cavity is often dilated below, forming a
smooth rounded prominence on the base of the skull, the auditory
bulla (Fig. 8). The three principal ossicles, the "malleus," " incus,"
and " stapes," are always present, but variable in characters. In
the Sirenia, Cetacea, and Seals they are massive in form, being in
the first-named order of larger size than in any other mammals. In
the Cetacea the malleus is ankylosed to the tympanic ; but in other
mammals it is connected only with the membrana tympani. The
stapes in the lower orders — Edentates, Marsupials, and Monotremes
74 GENERAL ANATOMICAL CHARACTERS
— has a great tendency to assume the columnar form of the
corresponding bone in Sauropsida, its two rami entirely or partially
coalescing. 1 The tympanic membrane (drum of the ear) forms the
outer wall of the cavity. In the foetal state it is level with the
external surface of the skull, and remains so permanently in a few
mammals, as the American Monkeys ; but commonly, by the growth
of the squamosal bone, it becomes deeply buried at the bottom of a
bony tube {meatus auditorus externus), which is continued to the sur-
face of the skin in a fibrous or fibrocartilaginous form. In Whales,
owing to the thickness of the subcutaneous adipose tissue, this
meatus is of great length, and is also extremely narrow. In most
aquatic and burrowing animals it opens upon the surface by a simple
aperture, but in the large majority of the class there is a projecting
fold of skin, strengthened by fibro- cartilages, called the pinna,
auricle, or " external ear," of very variable size and shape, generally
movably articulated on the skull, and provided with muscles to
vary its position ; this pinna helping to collect and direct the vibra-
tions of sound into the meatus.
VII. REPRODUCTIVE ORGANS.
Testes. — In the male the testes retain nearly their primitive or
internal position throughout life in the Monotremata, Sirenia,
Cetacea, most Edentata, Hyracoidea, Proboscidea, and Seals,
but in other groups they either periodically (as in Rodentia,
Insectivora, and Chiroptera) or permanently pass out of the
abdominal cavity through the inguinal canal, forming a projection
beneath the skin of the perineum, or becoming suspended in a
distinct pouch of integument called the scrotum. All the Marsupials
have a pedunculated scrotum, the position of which differs from
that of other mammals, being in front of, instead of behind, the
preputial orifice. As regards the presence, absence, or comparative
size and number of the accessory generative glands — prostate, vesi-
cular, and Cowper's glands, as they are called — there is much
variation in different groups of mammals.
Penis. — The penis is almost always completely developed,
consisting of two corpora cavernosa attached to the ischial bones,
and of a median corpus spongiosum enclosing the urethra, and
forming the glans at the distal portion of the organ. In Marsupials,
Monotremes, and the Sloths and Anteaters, the corpora cavernosa
are not attached directly to the ischia, and in the last-named the
penis is otherwise of a very rudimentary character, the corpus
1 The modifications of these bones are fully described by A. Doran, "Morpho-
logy of the Mammalian Ossicula auditus," Trans. Linn. Soc. ser. 2, vol. i. pp.
371-497, pi. lviii.-lxiv. (1878).
REPRODUCTIVE ORGANS 75
spongiosum not being present. In many Marsupials the glans penis
is bifurcated. In most Primates, Carnivora, Kodentia, Insectivora,
and Chiroptera, but in no other orders, an os penis is present.
Ovaries and Oviduct. — In the female, the ovaries permanently retain
their original abdominal position, or only descend a short distance
into the pelvis. They are of comparatively smaller size than in
other vertebrates, have a definite flattened oval form, and are
enclosed in a more or less firm " tunica albigenia." The oviduct
has a trumpet-like, and usually fimbriated abdominal aperture, and
is more or less differentiated into three portions : — (1) a contracted
upper part, called in Man and the higher mammals the " Fallopian
tube "; (2) an expanded part Avith muscular walls, in which the
ovum undergoes the changes by which it is developed into the
fcetus, called the " uterus "; (3) a canal, the " vagina," separated
from the last by a valvular aperture, and terminating in the urino-
genital canal, or common urinal and genital passage, which in
higher mammals is so short as scarcely to be distinct from the vagina.
The complete distinction of the oviducts of the two sides through-
out their whole length, found in all lower vertebrates, only occurs
in this class in Monotremes ; a prevailing mammalian characteristic
being their more or less perfect coalescence in the middle line to form
a single median canal. In the Marsupials this union only includes
the lower part of the vagina ; but in most Placentals it extends to the
whole vagina and a certain portion of the uterus, which cavity is
then described as "bicornuate." In the higher mammals, as in
Man, and also in some of the Edentates, the whole of the uterus is
single, the contracted upper portion of the oviducts or Fallopian
tubes, as they are then called, entering its upper lateral angles by
small apertures. In certain lower forms the urino- genital canal
opens with the termination of the rectum into a common cloaca,
as in other vertebrates ; but it is characteristic of the majority
of the class that the two orifices are more or less distinct exter-
nally.
Mammary Glands. — Mammary glands secreting the milk by
which the young are nourished during the first portion of their
existence after birth, are present in both sexes in all mammals,
though usually only functional in the female. In the Monotremes
alone their orifices are mere scattered pores in the skin, but in all
other forms they are situated upon the end of conical elevations,
called mammillae or teats, which, taken into the mouth of the
young animal, facilitate the process of sucking. These are always
placed in pairs upon some part of the ventral surface of the body,
but vary greatly in number and position in different groups. In
the Cetacea, where the prolonged action of sucking would be incom-
patible with their subaqueous life, the ducts of the glands are
dilated into large reservoirs from which the contents are injected
76 GENERAL ANATOMICAL CHARACTERS
into the mouth of the young animal by the action of a compressor
muscle.
Secondary Sexual Characters. — Secondary sexual characters, or
modifications of structure peculiar to one sex, but not directly
related to the reproductive function, are very general in mammals.
They almost always consist of the acquisition or perfection of some
character by the male as it attains maturity, which is not found in
the female or the young in either sex. In a large number of cases
these clearly relate to the combats in which the males of many
species engage for the possession of the females during the breeding-
season ; others are apparently ornamental, and of many it is still
difficult to apprehend the meaning. Many suggestions on this
subject will, however, be found in the chapters devoted to it in
Darwin's work on The Descent of Man and Selection in Relation to Sex,
where most of the best-known instances are collected. Superiority
of size and strength in the male of many species is a well-
marked secondary sexual character related to the purpose indicated
above, being probably perpetuated by the survivors or victors in
combats transmitting to their descendants those qualities which
gave them advantages over others of their kind. To the same
category belong the great development of the canine teeth of the
males of many species which do not use these organs in procuring
their food, as the Apes, Swine, Musk and some other Deer, the tusk
of the male Narwhal, the antlers of Deer, which are present in most
cases only in the males, and the usual superiority in size and
strength of the horns of the Bovidw. Other secondary sexual
characters, the use of which is not so obvious, or which may only
relate to ornament, are the presence of masses or tufts of long hair
on different parts of the body, as the mane of the male Lion and
Bison, the beards of some Ruminants and Bats (as Taphozous melano-
fogoii), Monkeys, and of Man, and all the variations of coloration
in the sexes, in which, as a general rule, the adult male is darker
and more vividly coloured than the female. Here may also be
mentioned the presence or the greater development of odoriferous
glands in the male, as in the Musk Deer, and the remarkable
perforated spur with its glands and duct, so like the poison-tooth
of the venomous serpents, found in the males of both Ornithorhynchns
and Echidna, the use of which is at present unknown.
Placenta. — The development of the mammalian ovum, and the
changes which the various tissues and organs of the body undergo
in the process of groAvth, are too intricate subjects to be explained
without entering into details incompatible with the limits of this
work, especially as they scarcely differ, excepting in their later
stages, from those of other vertebrates, upon which, owing to the
greater facilities these present for examination and study, the
subject has been more fully worked out. There are, however,
REPRODUCTIVE ORGANS 77
some points -which require notice, as peculiar to the mammalian
class, and as affording at least some hints upon the difficult subject
of the affinities and classification of the members of the group.
The nourishment of the foetus during intra-uterine life takes
place through the medium of certain structures, partly belonging
to the foetus itself and partly belonging to the inner parietes of the
uterus of the parent. These in their complete form constitute the
complex organ called the "placenta," serving as the medium of
communication between the mother and foetus, and in which the
physiological processes that are concerned in the nutrition of the
latter take place ; but, as "we shall see, though a placenta, in the
usual acceptation of the term, is peculiar to the mammalian class, it is
not in all of its members that one is developed. The structures to
which we shall have especially to refer are the outer tunic of the
ovuni, to which, however formed, the term " chorion " is commonly
applied, and two sac-like organs connected with the body-cavity of
the embryo, both formed from the splanchnic mesoblast, lined by a
layer of the hypoblast. These are the " umbilical vesicle " or " yolk-
sac" and the "allantois."
The umbilical vesicle is a thin membrane enclosing the yolk,
which by the doubling in of the ventral walls of the embryo becomes
gradually formed into a distinct sac external to the body, with a
pedicle (the omphalo-enteric duct) by which for a time a communica-
tion is maintained between its cavity and the intestinal canal. In
the walls of this sac blood-vessels (omphalo-meseraic or vitelline)
are developed in connection with the vascular system of the embryo,
through which, either by their contact with the outer surface of the
walls of the ovum, or by the absorption through them of the
contents of the yolk-sac, the nutrition of the embryo in the lower
vertebrates chiefly takes place. In mammals the umbilical ves-
icle plays a comparatively subordinate part in the nourishment
of the foetus, its function being generally superseded by the
allantois.
The last-named sac commences at a very early period as a
diverticulum from the hinder end of the alimentary tract of the
embryo. Its proximal portion afterwards becomes the urinary
bladder, the contracted part between this and the cavity of the
allantois proper constituting the urachus, which passes out of the
body of the foetus at the umbilicus together with the vitelline duct.
The mesoblastic tissue of the walls of the allantois soon becomes
vascular ; its arteries are supplied with foetal blood by the two
hypogastric branches of the iliacs, or main divisions of the abdominal
aorta, and the blood is returned by venous trunks uniting to
form the sinerle umbilical vein which runs to the under surface of
the liver, where, part of it joining the portal vein and part entering
the vena cava directly, it is brought to the heart. These are
73 GENERAL ANATOMICAL CHARACTERS
the vessels which, with their surrounding membranes, consti-
tute the umbilical cord — the medium of communication between
the foetus and the placenta, when that organ is fully de-
veloped.
The egg membranes of the Monotremes present many points of
agreement with those of the ovum of the Marsupials, 1 and differ
from those of the Placental types. Thus Monotremes and Marsu-
pials agree in having a vitelline membrane, which appears between
the young ovum and the follicular epithelium, persisting in the
one ^ case until the time of hatching, and in the other till a late
uterine stage. There are also several other common features fully
described in Mr. Caldwell's memoir, but which cannot be detailed
in this work.
In the Marsupialia the observations made many years ago by
Sir R. Owen upon the development of the Kangaroo have been
confirmed by those of Dr. H. C. Chapman, 2 while Dr. Selenka, 3 and
Professor H. F. Osborn 4 have contributed important evidence as to the
structure and relations of the foetal membranes of the Opossums
and others. It thus appears that up to the period of the very
premature birth of these animals the outer covering of the ovum,
or false chorion, is free from persistent villi, and .not adherent
to the epithelium of the uterine walls ; for, although fitting into
the folds of the latter, it is perfectly and readily separable in its
entire extent from them. The umbilical vesicle or yolk-sac is large,
vascular, and adherent to a considerable portion of the false chorion
or subzonal membrane, while the allantois is relatively small, and
although the usual blood-vessels can be traced into it, it does not
appear to contract any connection with the false chorion, and, there-
fore, much less with the Avails of the uterus, of such a nature as to
constitute a placenta. In some forms, however, such as the
Opossums, the umbilical vesicle or yolk-sac develops temporary
villi, Avhich unite with the subzonal membrane, or false chorion, to
form a disc -like area closely attached to the cells covering the
utricular glands of the uterine epithelium, and thus forming a
so-called yolk-sac placenta. The function of this organ is considered
to be the transmission of the secretions of the utricular glands to
the embryo by means of the umbilical vesicle ; the function of the
allantois being either respiratory or the absorption of the fluid
secreted in the uterine cavity by the utricular glands.
While in the uterus the nourishment of the foetus seems, there-
fore, to be derived from the umbilical vesicle, as in reptiles and
1 See B. H. Caldwell— "The Embryology of Monotremata and Marsupialia,"
Phil. Trans, for 1887, p. 463.
2 Proc. Acad. Nat. Sci. Philadelphia, 1881, p. 468.
3 " Studienueber Entivickelungeschichtc dcr Thierc," pt. 4, Wiesbaden, 1886.
4 Journal of Morphology, vol. i. p. 373 (1887).
REPRODUCTIVE ORGANS 79
birds, rather than from the uterine Avails by means of the allantoic
vessels, as in the higher mammals. The latter vessels, in fact, play
oven a much less important part in the development of these
animals, not only than in the placental mammals, but even than in
the Sauropsida, for they can scarcely have the respiratory function
assigned to them in that group: pulmonary respiration and the
lacteal secretion of the mother very early superseding all other
methods of providing the due supply both of oxygen and of food
required for the development and growth of the young animal.
in this sense the Marsupials may be looked upon as the most
typically " mammalian " of the whole class. In no other group do
the milk -secreting glands play such an important part in pro-
viding for the continuity of the race.
In the third primary division of the Mammalia, the so-called
Placentalia, the umbilical vesicle generally does not quite unite
with the chorion, and disappears as development proceeds, so that
no trace of it can be seen in the membranes of an advanced
embryo ; but it may persist until the end of the intra-uterine life
as a distinct sac in the umbilical cord, or lying between the
allantois and amnion. The disappearance or persistence of the
umbilical vesicle does not, according to our present knowledge,
appear to be correlated with a higher or lower general grade of de-
velopment, as might be presupposed. It is stated to have been
found in Man even up to the end of intra-uterine life, and also in
the Carnivora, while in the Ungulata and Cetacea it disappears at
an earlier age. In many, if not all, of the Rodentia, Insectivora,
and Chiroptera, it plays a more important part, becoming adherent
to a considerable part of the inner surface of the chorion, to which
it conveys blood-vessels, although villi do not appear to be developed
from the surface of this part, as they are on the portion of the
chorion supplied by the allantoic vessels. These orders thus
present to a certain extent a transitional condition from the Mar-
supials, although essentially different, in possessing the structures
next to be described.
The special characteristic of the whole of the placental mammals
constituting the majority of the class, is that the allantois and its
vessels become intimately blended with a smaller or greater part of
the parietes of the ovum, forming a structure on the outer surface of
which villi are developed, and which, penetrating into corresponding
cavities of the " decidua," or soft, vascular, hypertrophied lining
membrane of the uterus, constitutes the placenta. This organ may
be regarded, as Sir William Turner says, both in its function and in
the relative arrangement of its constituent textures, as a specially
modified secreting gland, the ducts of which are represented by the
extremities of the blood-vessels of the foetal system. The passage
of material from the maternal to the foetal system of vessels is not
So GENERAL ANATOMICAL CHARACTERS
a simple percolation or diffusion through their walls, but is oc-
casioned by the action of a layer of cells derived from the maternal
or uterine structures, and interposed between the blood-vessels of
the maternal part of the placenta and those of the villi covering
the chorion, in which the embryonic vessels ramify.
The numerous modifications in the details of the structure of
this organ relate to augmenting the absorbing capacity of the vessels
of the chorion, and are brought about either by increasing the com-
plexity of the foetal villi and maternal crypts over a limited area,
or by increasing the area of the part of the chorion covered by the
placental villi, or by various combinations of the two methods.
The first class of variations has given rise to a distinction into
two principal kinds of placenta: (1) simple or non-deciduate, and
(2) deciduate. In the former the foetal villi are received into corre-
sponding depressions of the maternal surface, from which at the
period of parturition thej r are simply withdrawn. In the second,
or more complex form, the relation is more intimate, a layer of
greater or less thickness of the lining membrane of the uterus,
called " decidua," becoming so intimately blended with the chorion
as to form part of the placenta proper, or that structure which is
cast off as a solid body at parturition. In other words, in the one
case the line of separation between the placenta and uterus at birth
takes place at the junction of the foetal and maternal structures, in
the other through the latter, so that a portion of them, often of con-
siderable thickness, and containing highly organised structures, is
cast off with the former. It was once thought that the distinction
between these two forms of placentation is so important as to con-
stitute a sufficiently valid basis for a primary division of the pla-
cental mammals into two groups. It has, however, been shown
that the distinction is one rather of degree than of kind, as inter-
mediate conditions may exist, and it is probable that in different
primary groups the simpler, non-deciduate form may have become
developed independently into one or other of the more complex
kinds.
Apart from its intimate structure, the placenta may be met with
of very varied general form. It may consist of villi scattered more
or less regularly over the greater part of the surface of the chorion,
the two extremities or poles being usually more or less bare. This
form is called the " diffused placenta." It is probably a primitive
condition, from which most of the others are derived, although its
existence must presuppose the absence of the umbilical vesicle as a
constituent of the chorionic wall. It is found at present in the
Manis among Edentates, the Cetacea, the Perissodactyle Ungulates,
and the Camels, Pigs, and Chevrotains among the Artiodactyles.
Such placentae are always non-deciduate. Kecent observations by
Sir W. Turner on the placentation of the Dugong show that the
REPRODUCTIVE ORGANS Si
Sironia present the peculiarity of having a zonary placenta, which is
either entirely or in great part non-deciduate, and is, therefore,
transitional between the diffused and the true zonary type.
In the true Ruminants or Pecora, among the Artiodactyle
Ungulates, the villi are aggregated in masses called cotyledons,
with bare spaces between. Such a placentation is called "poly-
cotyledonary." In another modification the villi are collected in a
more or less broad band encircling the chorion, leaving a very large
portion of the two poles bare, constituting the "zonary placenta,"
characteristic of the Carnivora, and also occurring in the Elephant,
Hyrax, and Orycteropus. The fact of the form of the placenta of
these three last-named animals agreeing together, and with that of
the Carnivora, does not, however, necessitate the ascription of
zoological affinities, as the same ultimate form may have been
attained by different processes of development.
In another form one pole only of the chorion is non-vascular,
the placenta assuming a dome or bell shape, as in the Lemurs and
the Sloths. The transition from this, by the gradual restriction of
the vascular area, is easy to the oval or discoidal form of placenta
of the Anteaters, Armadillos, and higher Primates. The discoidal
placenta of the Rodents, Insectivores, and Chiroptera, though show-
ing so much superficial resemblance to that of the last-named order
as to have led to the inclusion of all these forms in one primary
group, is now known to be developed in another manner, not by the
concentration of villi from a diffused to a limited area, but by
retaining the area to which it was originally restricted in con-
sequence of the large surface of the chorion occupied, as before
mentioned, by the umbilical vesicle. To compensate for the small-
ness of area, the complex or deciduate structure has been developed.
Among some Rodents there is evidence to show that the discoidal
placenta has been derived from a zonary one, of which distinct
vestiges have been detected in the Mouse. We may conclude
that, although the characters and arrangement of the foetal structures
may not have that extreme importance which has been attributed
to them by some zoologists, they will form, especially when more
completely understood, valuable aids in the study of the natural
affinities and evolution of the Mammalia. 1
1 For a full exposition of the present state of knowledge on this subject, see
the various memoirs of Sir "William Turner, also F. M. Balfour's Treatise on
Comparative Embryology, vol. ii. (1881), and J. A. Ryder in American Naturalist,
vol. xxi. p. 780 (1887).
CHAPTEE III
ORIGIN AND CLASSIFICATION OF THE MAMMALIA
Origin. — Although, as stated in the first chapter, the mammalian
class, as at present known either by existing or extinct forms, is
completely isolated from all other groups of the animal kingdom,
yet it is impossible to refrain from speculating as to its origin and
nearest affinities. In arranging the classes of vertebrates in a linear
series it is customary to place them in the following order — Pisces,
Amphibia, Reptilia, Aves, Mammalia, — an order which probably
indicates the relative degree of elevation to which the mos
highly developed members of each class has attained. Such
an arrangement appears to express the true relationship of the first
four classes to one another, but it is quite clear that the Mammalia
have no sort of affinity with the Aves. Writing in 1879, Professor
Huxley l came to the conclusion that, in looking among vertebrates
for the progenitors of the Mammalia, we must pass over all known
forms of birds and reptiles, and go straight clown to the Amphibia.
In addition to the characters derived from the conformation of the
pelvis upon which the argument was primarily based, the following
reasons were given for this conclusion : " The Amphibia are the
only air-breathing Vertebrata which, like mammals, have a dicon-
dylian skull. It is only in them that the articular element of the
mandibular arch remains cartilaginous, while the quadrate ossifica-
tion is small, and the squamosal extends down over it to the osseous
elements of the mandible, thus affording an easy transition to the
mammalian condition of those parts. The pectoral arch [girdle] of
the Monotremes is as much amphibian as it is sauropsidian ; the
carpus and the tarsus of all Sauropsida, except the Chelonia, are
modified away from the Urodele type, while those of the mammal
are directly reducible to it. Finally, the fact that in all Sauropsida
it is a right aortic arch which is the main conduit of arterial blood
leaving the heart, while in mammals it is a left aortic arch which
1 Proceedings of the Royal Society of London, vol. xxviii. p. 395 (1879).
ORIGIN 83
performs this office, is a great stumbling-block in the way of the
derivation of the Mammalia from any of the Sauropsida. But, if
we suppose the earliest forms of both the Mammalia and the Saur-
opsida to have had a common Amphibian origin, there is no difficulty
in the supposition that, from the first, it was a left aortic arch in
the one series, and the corresponding right aortic arch in the other,
which became the predominant feeder of the arterial system."
Subsequently Professor E. D. Cope l in a suggestive paper called
attention to the remarkable resemblances to the Monotremes pre-
sented by the skeleton of that group of early secondary reptiles
which he then designated the Theromorpha, but which may be
included in the Anomodontia of Sir R. Owen, and came to the
conclusion that in that group we have the true ancestors of the
Mammalia. This conclusion was, however, disputed by Dr. Baur, 2
who considered that the Anomodontia were too specialised to have
been the actual progenitors of the Mammalia, and that they should
rather be regarded as a divergent branch of the stem which had given
origin to the Mammalia. Since that date observations made on
the structure of the South African Anomodonts have shown such
an intimate connection between that group and the Labyrinthodont
Amphibians, that there can be no hesitation in regarding the one
as the direct descendant of the other ; and we may probably regard
the Mammalia as having originated from the same ancestral stock
at the time the Amphibian type was passing into the Reptilian.
From this point of view, some of the mammalian features found in
the more specialised Anomodonts may probably be regarded as
having been acquired during a parallel line of development.
Both the Anomodontia and the Mammalia differ from the
Amphibians in the loss of the splint- like parasphenoid which
underlies the basisphenoid axis of the skull, and by the ossification
of that axis ; but while the former have become monocondylic by
the participation of the basioccipital in the support of the cranium,
the latter retain the Amphibian dicondylic plan. The skull of the
Anomodonts presents mammalian resemblances not found in any
other Reptiles, this being especially noticeable in the region of the
squamosal ; and it is only in this group and mammals that the
temporal or zygomatic arch is a squamoso-maxillary one (see p.
37). The resemblance between the pectoral and pelvic girdles
of the Anomodonts and those of the Monotreme Mammals is
noticed under the head of the latter, where reference is also made
to the similarity in the structure of the humerus in the two groups.
1 " The Relations between the Theromorphous Reptiles and the Monotreme
Mammalia," Proceedings of the American Association for the Advancement of
Science, vol. xxxiii. p. 471 (1885).
- "On the Phylogenetic Arrangement of the Sauropsida," Journal of
Morphology, vol. i. pp. 93-104 (1887).
84 ORIGIN AND CLASSIFICATION
The pes of the Amphibia and Anomodontia agree in having a
distinct intermedium, tibiale, fibulare, and centrale, whereas in
other Reptiles these bones are not generally distinct ; in Mammals
the intermedium, fibulare, and centrale are distinct, and according
to Cope's interpretation there may be a distinct tibiale.
Classification. — In the present condition of the world, mammals
have become so broken up into distinct groups by the extinction of
intermediate forms, that a systematic classification is perfectly
practicable. Most of the associations of species, which Ave call
" orders," and even the " suborders " and " families," are natural
groups. In isolating, defining, and naming them, we are really
dealing with facts of nature of a totally different order from the
artificial and fanciful divisions formed in the infancy of zoological
science.
When, however, we pass to the extinct world, all is changed.
In many cases the boundaries of our groups become enlarged until
they touch those of others. New forms are discovered which
cannot be placed within any of the existing divisions. As the
horizon of our vision is thus expanded, the principles upon which a
scheme of classification is constructed must be altogether changed.
Our present divisions and terminology are no longer sufficient for
the purpose ; and some other method will have to be invented to
show the complex relationships existing between different animal
forms when viewed as a whole. The present time, pre-eminently
distinguished by the rapidly changing and advancing knowledge of
extinct forms, is scarcely one in which this can be done with any
satisfactory result ; so that all attempts to form a classification
embracing even the already known extinct species must be only
of a provisional and temporary nature.
In systematic descriptions in books, in lists, and catalogues, and
in arranging collections, the objects dealt with must be placed in a
single linear series. But by no means whatever can such a series
be made to coincide "with natural affinities. The artificial character
of such an arrangement, the constant violation of all true relation-
ships, are the more painfully evident the greater the knowledge of
the real structure and affinities. But the necessity is obvious ; and
all that can be done is to make such an arrangement as little as
possible discordant with facts.
The following table contains a list of the orders, suborders, and
families of existing mammals as recognised by the authors, and placed
in the order in which they will be treated of in this work. The
more important of the groups containing only extinct forms are
added in a different type, being interpolated, as near as may be,
among those that appear to be their existing relatives.
A few explanatory remarks upon the mutual relations of some
of the principal groups mentioned in the table may be useful here,
CLA SSIFICA TION 8 5
but the subject will be more fully developed in treating separately
of each division.
One of the most certain and fundamental points in the classifica-
tion of the Mammalia is, that all the animals now composing the
class can be grouped primarily into three natural divisions, which,
presenting very marked differential characters, and having no exist-
ing, or yet certainly demonstrated extinct, intermediate, or trans-
itional forms, may be considered as subclasses of equal value, tax-
onomically speaking, though very different in the numbers and
importance of the animals at present composing them. These three
groups are often called by the names originally proposed for them
by Blainville — (1) Ornithodelphia, (2) Didelphia, (3) Monodelphia —
the first being equivalent to the order Monotremata, the second
to the Marsupiidia, and the third including all the remaining
members of the class. Although actual pala?ontological proof is
wanting, there is much reason to believe that each of these, as now
existing, are survivors of distinct branches to which the earliest
forms of mammals have successively given rise, and for which
hypothetical branches Professor Huxley has proposed the names of
Prntotheria, Metatheria, and Eutheria, names which, being far less
open to objection than those of Blainville, are here used as equiva-
lents of the latter.
The only known existing Prototheria, although agreeing in
many important characters, evidently represent two very divergent
stocks, perhaps as far removed as are the members of some of the
accepted orders of the Eutheria. It would, however, be merely
encumbering zoological science with new names to give them any
other than the ordinarily known family designations of Ornitho-
rhynchidce and Echidnidce.
Similarly with regard to the Metatheria, although the great
diversity in external form, in anatomical characters, and in mode of
life of the various animals of this section might lead to their
division into groups equivalent to the orders of the Eutheria, we do
not think it advisable to depart from the usual custom of treating
them all as forming one order, called Marsupialia, the limits of
which are equivalent to those of the subclass. The characters of the
six families which compose the group are extremely well ma/rked
and easily defined ; and since they form a regular gradation between
two extreme types, they can be satisfactorily arranged in a serial
order. A marked distinction in the dentition enables us to divide
them into primary groups or suborders.
The remaining mammals are included in the Eutheria, Placen-
talia, or Monodelphta. Their affinities with one another are so
complex that it is impossible to arrange them serially with any
regard to natural affinities. Indeed each order is now so isolated
that it is almost impossible to say what its affinities are ; and none
86 ORIGIN AND CLASSIFICATION
of the hitherto proposed associations of the orders into larger groups
stand the test of critical investigation. All serial arrangements of
the orders are therefore perfectly arbitrary ; and although it would
be of very great convenience for reference in books and museums
if some general sequence, such as that here proposed, were generally
adopted, such a result can scarcely be expected, since equally good
reasons might be given for almost any other combination of the
various elements of which the series is composed. In fact, we have
already seen reason to depart in some respects from that used in the
" Encyclopedia."
The Edentata, Sirenia, and Cetacea stand apart from all the
rest in the fact that their dentition does not conform to the general
heterodont, diphyodont type to which that of all other Eutheria
can be reduced, and which is such a close bond of union between
them. In all three orders, however, some indications may be traced
of relationship, however distant, with the general type.
With regard to the Edentata, reasons will be given for believing
that both the Sloths and Anteaters are nearly related, and that the
Armadillos, though much modified, belong to the same stock, but
that the Pangolins and the Aard-varks represent very isolated
forms.
There is no difficulty about the limits of the order Sirenia, com-
prising aquatic, vegetable-eating animals, with complete absence of
hind limbs, and low cerebral organisation, represented in our present
state of knowledge only by two existing genera, Halicore and Mana-
tus, and a few extinct forms, which, though approaching a more
generalised mammalian type, show no special characters allying
them to any of the other orders. The few facts as yet collected
relating to the former history of the Sirenia leave us as much in
the dark as to the origin and affinities of this peculiar group of
animals as we were when Ave only knew the living members.
They lend no countenance to their association with the Cetacea ;
and, on the other hand, their supposed affinity with the Ungulata
receives no very material support from them.
Another equally well-marked and equally isolated, though far
more numerously represented and diversified order, is that of the
Cetacea, placed simply for convenience next to the Sirenia ; with
Avhich, except in their fish-like adaptation to aquatic life, they have
little in common. The old association of these orders in one group
can only be maintained either in ignorance of their structure or
in an avowedly artificial system. Among the existing members of
the order, there are two very distinct types, the toothed Whales or
Odontoceti, and the Baleen Whales or Mystacoceti, which present
as many marked distinguishing structural characters as are found
between many other divisions of the Mammalia usually reckoned
as orders. Since the extinct Zeuglodonts, so far as their characters
CLASSIFICATION 87
are known, do not fall into either of these groups, but are in some
respects annectant forms, we have placed them provisionally, at
least, in a third group by themselves, named Arclneoceti. There
is nothing known at present to connect the Cetacea with any
other order of Mammals ; but it is quite as likely that they are
offsets of a primitive Ungulate as of a Carnivorous type, or perhaps
of a still more generalised mammalian stock.
The remaining Eutherian mammals are clearly united by the
characters of their teeth, being all heterodont and diphyodont, with
their dental system reducible to a common formula.
Although older views of, the relationship of Ungulate mammals
expressed by the terms Pachydermaia, Ruminantia, and so forth, still
linger in some corners of zoological literature, no single point in
zoological classification can be considered so firmly established as the
distinction between the Perissodactyle and Artiodactyle Ungulates ;
both being in the existing fauna of the world perfectly natural
and distinctly circumscribed groups. The breaking-up of the latter
into four equivalent sections, the Pecora, Tylopoda, Tragulina, and
Suina, is equally in accordance with all known facts. Less certain,
however, is the association of the Proboscidea and the Hyracoidea
with the true Ungulates. By many zoologists they are each,
although containing so very few existing species, made into distinct
orders ; and much is to be said in favour of this view. The
discovery, however, of a vast number of extinct species of Ungu-
lates which cannot be brought under the definition of either Perisso-
dactyla or Artiodactyla, and yet are evidently allied to both, and
to a certain extent bridge over the interval between them and the
isolated groups just mentioned, make it necessary either to intro-
duce a number of new and ill-defined ordinal divisions, or so to
widen the scope of the original order as to embrace them all,
considering the Elephants and the Hyraces as representing sub-
orders equivalent to the great Perissodactyle and Artiodactyle groups.
It is the latter alternative that we have adopted.
The Rodentia, although generally presenting a low grade of
development, are a very specialised and distinct group. The
position here assigned to them would accord with apparent relation-
ships with the Ungulates, through the Elephant on the one hand
and the extinct Tijpotherium on the other.
In the present state of the fauna of the earth, the Carnivora
form a very distinct order, though naturally subdivided into two
groups, the members of the one being more typical, while those of
the other (the Pinnvpedia) are aberrant, having the whole of their
organisation specially modified for living habitually in the water.
The Insectivora comprise various lowly organised and generalised
forms, exhibiting considerable divergence of character, and ap-
parently connected through transitional extinct species with the
88 ORIGIN AND CLASSIFICATION
Carnivora. As no other order can claim the family Galeopithecidce,
it is placed here, but rather for convenience than for any other
consideration, since it has but little if any relationship with any of
the other members. Its isolated position is indicated by assigning
it a distinct subordinal rank.
The Chiroptera have always been placed near the Insectivora ;
but they are really a highly specialised group, as much isolated
from all other mammals by the modification of their anterior limbs
in adaptation to aerial locomotion, as the Cetacea and the Sirenia,
by the absence of hind limbs, are specially adapted for an aquatic
life.
Lastly, the Primates, which in any natural system must be
placed at the head of the series, are divisible into two very distinct
groups — one containing the various forms of Lemurs (Lemuroidea),
and the other the Monkeys and Man (Anthropoidea). Whether
the Lemuroidea should form part of the Primates (according to the
traditional view), or a distinct order altogether removed from it,
is as yet an undetermined question, for both sides of which there
is much to be said. There can, however, be no doubt that the
Anthropoidea form a perfectly natural group, presenting a series
of tolerably regular gradations from the Marmosets {Hapxdc) to
Man. Certain breaks in the series, however, enable us to divide
it into five distinct families : — Hapalida' or Marmosets ; Cebiclce or
American Monkeys, with three premolar teeth on each side of each
jaw ; Cercopithecidce, containing the majority of Old-world Monkeys ;
Simiidce, consisting of the genera Hylobates, Simia, Gorilla, and
Anthropopithecus, the true Man -like Apes; and, lastly, LTominida;
containing the genus Homo alone.
Subclass I. Prototheria.
Order i. Monotremata — Monotremes.
Fam. 1. OrnithorhynchidcB — Duck-bill.
2. Echidnidce — Spiny Anteater.
Group. MULTITUBERCULATA. 1
Fam. 1. Plagiaulacidse — Plagiaulax.
2. Polymastodontidae — Polymastodon.
3. Tritylodontidse — Tritylodon.
Subclass II. Metatheria.
Order ii. Marsupialia — Marsupials.
Suborder 1. Polyprotodontia — Polyprotodonts.
1 The names of the groups containing only extinct forms are printed in heavier
type than those which contain species still existing.
CLASSIFICATION 89
Fain. 1. Dromatheriidae — Dromatherium.
■1. Amphitheriidae — AmpMtherium, etc
3. Spalacotheriidae — Spnlacotherium.
4. Tritylodontidae — Tritylodon.
5. Dideljihyidiv — Opossums.
I!. Dasyuridce — Thylacine and Dasyures.
7. l'cramelidcc — Bandicoots.
Suborder 2. Diprotodontia — Diprotodonts.
Fam. 8. Phascolomyidce — Wombats.
9. PhalangeridoB — Phalangers.
1 0. Diprotodontidse— Diprotodon.
11. Nototheriidae — Notothere.
1 2. Macropodidce — Kangaroos.
Subclass III. EUTHEKIA.
Order iii. Edentata — Edentates.
Fam. 1. Bradypodidce — Sloths.
2. Megatheriidae — Ground Sloths.
3. Myrmecophagidce — Anteaters.
4. Dasypodidce — Armadillos.
5. Glyptodontidae — Glyptodonts.
G. Manidce — Pangolins.
7. Oryeteropodidoe — Aard-varks.
Order iv. SlRENlA — Sirenians.
Fam. 1. Manatidce — Manatees.
2. Rhytinidae — Rhytina.
3. Halicoridce — Dugongs.
4. Halitheriidae — Halithere.
Order v. Cetacea — Cetaceans.
Suborder 1. Mystacoceti — Baleen Whales.
Fam. 1. Balcenidce — Greenland Whale, etc.
Suborder 2. ARCILEOCETI.
Fam. 2. Zeuglodontidae — Zeuglodonts.
Suborder 3. Odontoceti — Toothed Whales.
Fam. 3. Physeteridce — Sperm Whale.
4. Platanistidce — Freshwater Dolphins.
5. Delphinidce — Dolphins, Porpoises, etc.
Order vi. Ungulata — Hoofed Mammals.
Suborder 1. Artiodactyla — Artiodactyles.
Section A. Suina — Pig-like Artiodactyles.
Fam. 1. Hippopotamidce — Hippopotamus.
2. Suidce — Pigs and Peccaries.
9o ORIGIN AND CLASSIFICATION
1 h\
3. Choeropotamidae — Chceropotamus.
4. Anthracotheriidae — Anthracothere.
5. Merycopotamidae — Merycopotainus.
6. Cotylopidse — Oreodonts.
7. Anoplotheriidae — Anoplothere.
8. Dichodontidae — Dichodon.
Tragulina — Chevrotains.
TragulidoB — Clievrotains.
Tylopoda — Camels.
Camelidce — Camels and Llamas.
Poebrotheriidae — Poebrotherium.
Pecora — True Ruminants.
Cervidce — Deer.
Giraffidce — Giraffe.
Antilocapridce — Prong-buck.
Bovidce — Sbeep, Cattle, etc.
Perissodactyla — Perissodactyles.
Tapiridee — Tapirs.
Lophiodontidae — Loplnodonts.
Palaeotheriidae — Palieotheres.
Eqwidce — Horses.
Rhinocerotidce — Rhinoceroses.
Lambdotheriidae — Palaeosyops.
Chalicotheriidae — Chalicothere.
Titanotheriidae — Titanotbere.
Macraucheniidae — Macrauchenia.
TOXODONTIA— Toxodonts.
Toxodontidae — Toxodon.
Typotheriidas — Typothere.
Suborder 4. CONDYLARTHRA
Fam. 27. Periptychidae — Periptychus.
28. Phenacodontidae — Phenacodus.
29. Meniscotheriidae — Meniscothere.
Suborder 5. Hyracoidea — Hyraces.
Fam. 30. Hyracidce — Hyrax.
Suborder 6. AMBLYPODA.
Fam. 31. Pantolambdidae — Pantolambda.
32. Coryphodontidas — Coryphodon.
33. Uintatheriidae — Uintathere.
Suborder 7. Proboscidea — Proboscideans.
Fam. 34. Dinotheriidae — Dinotbere.
35. Elephantidce — Elephants.
Section B.
9.
Section C.
10.
11.
Section D.
12.
13.
14.
15.
Suborder 2.
Fam. 16.
17.
18.
19.
20.
21.
22.
23.
24.
Suborder 3.
Fam. 25.
26.
CLA SSIFICA TION 9 1
Group. TILLODONTIA— Tillodonts.
Fam. Anchippodontidae — Anchippodus.
Calamodontidae — Calamodon.
Order vii. Eodentia — Kodents.
Suborder 1. Simplicidentata.
Fam. 1. Anomaluridcc — Auomalurus.
2. Sciurida? — Squirrels and Marmots.
3. Haplodontidcc — Haplodon.
4. Ischyroniyidae — Ischyromys.
6. Myoxidce — Dormice.
7. Lophiomyidre — Lophiomys.
8. Muridce — Rats, Mice, and Voles.
9. Spalacidcc— Mole-rats.
TO. Geomyida; — Pouched Rats.
1 1 . Dipodidce — Jerboas.
1 2. Theridomyidae — Theridomys.
13. Octodontidce — Spiny Mice.
1 4. Oastoroididae — Castoroides.
1 5. Hystricidic — Porcupines.
1 6. Chinchillidce — Chinchillas.
17. Dinomyidce — Dinomys.
1 8. Caviidce — Cavies.
1 9. Dasyproctidre — Agouties.
Suborder 2. Duplicidentata.
Fam. 20. Lagomyidce — Picas.
21. Leporidce — Hares and Rabbits.
Order viii. Carnivora — Carnivores.
Suborder 1. Carnivora Vera — Fissipedes.
Fam. 1. Felidce — Cats.
2. Hycewidce — Hyaenas.
3. Proteleidce — Earth-wolf.
4. Viverridce — Civets and Ichneumons.
5. Canidce — "Wolves and Foxes.
6. Vr&idM — Bears.
7. Mustelidce — -Weasels and Otters.
8. P?-ocyonidce — Racoons and Cat-bear.
Suborder 2. Pinnipedia — Pinnipedes.
Fam. 9. Otariidce — Eared Seals.
1 0. Trichechidce — Walrus.
1 1 . Phocidos — Seals.
Suborder 3. CREODONTA — Creodonts.
Fam. 12. Hyaenodontidae — Hycenodon.
1 3. Proviverridae — Proviverra.
14. Arctocyonidae — Arctocyon.
1 5. Mesonychidae — Mesonyx.
92 ORIGIN AND CLASSIFICATION
Order ix. Insectivora — Insectivores.
Suborder 1. Insectivora Vera.
Fam. 1. Tupaiidce — Tupaias.
2. Macroscelididce — Elephant-Shrews.
3. Erinaceidce — Hedgehogs.
4. Soricidce — Shrews.
5. TalpidoB — Moles.
6. Potamogalidce — Potamogale.
7. Solenodontidce — Solenodon.
8. Centetidce — Centetes.
9. Chrysochloridce — Golden Moles.
Suborder 2. Dermoptera.
Fam. 10. GaleopithecidcB — Galeopithecus.
Order x. Chiroptera — Bats.
Suborder 1. Megachiroptera — Frugivorous Bats.
Fain. 1. Pteropodidce — Flying Foxes.
Suborder 2. Microchiroptera — Insectivorous Bats.
Fam. 2. Vespertilionidce — Common Bats.
3. Nycteridce — Nycteris.
4. Rhinolophidce — Leaf-nosed Bats.
5. Emhallommdce — Emballonura.
6. Phyllostomatidce — Vampy res.
Order xi. Primates.
Suborder 1. Lemuroidea — Lemuroids.
Fam. 1. Hyopsodontidae — Hyopsodus.
2. Chiromyidce — Aye-Aye.
3. Tarsiidce — Tarsier.
4. Lemuridce — Lemurs.
Suborder 2. Anthropoidea — Anthropoids.
Fam. 5. Hapalidce — Marmosets.
6. Cebidce — American Monkeys.
7. Cercopithecidce — Old World Monkeys.
8. Simiidce — Gibbons and Man-like Apes.
9. Hominidce. — Man.
The distinctive character of these subclasses and orders, with an
account of their subdivisions and the principal forms contained in
each, will be given in subsequent chapters.
CHAPTER IV
GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION
I. GEOGRAPHICAL DISTRIBUTION. 1
In considering the present distribution of mammals over the
globe, Ave may, in the first place, direct our attention to terrestrial
or land types, reserving the consideration of aerial types, like the
Bats, and aquatic forms, as exemplified by the Cetaceans, Sirenians,
and Seals, to separate sections.
Among terrestrial forms each species has a certain definite area
of distribution in space, which may be of very wide extent, or may
be confined to a restricted region. This distributional area is,
however, always connected, or continuous ; that is to say, that
although we may have a single species inhabiting two continents,
like the Lion in Asia and Africa, or dwelling both on a continent
and adjacent continental islands, like the Javan Rhinoceros of India,
Java, and Borneo, yet we shall always find that such areas, if not
still connected, show evident signs of having been so connected
in comparatively late geological epochs ; and we never find
instances of the same species inhabiting totally disconnected areas,
such as India and South America. As examples of mammals
with a wide distribution we may mention the Lion and the
Leopard, Avhich are now found throughout Africa, and also occur
in India, as well as in the intervening areas of Arabia and Persia.
In the case of the former species, palaeontology further teaches us
that its distribution in the last geological epoch was even more
extensive, since we have good evidence to show that it formerly
ranged over the greater part of Europe, including the British Isles.
The Jackal affords another well-known instance of a species common
1 On this subject see A. Murray, Geographical Distribution of Mammals, 1866 ;
and especially A. R. Wallace, The Geographical Distribution of Animals, 2 vols.,
1876, and Island Life, 1881 ; also A. Heilprin, The Geographical and Geological
Distribution of Animals, 1887.
94 GEOGRAPHICAL DISTRIBUTION
to India and Africa. The American Puma, again, may be cited as
an example of a mammal having a very wide range in latitude,
since it is found from Patagonia in the south to Canada in the
north. As instances of wide range in the opposite direction we
have only to mention the Reindeer and the Elk or Moose, found
in the northern regions of both the Old and New Worlds, which
are only separated from one another by the narrow channel of
Behring Strait.
Of mammals with extremely restricted distributional areas, we
may mention many of the Insectivora, such as the Desman of the
Pyrenees, and some of the Madagascar types of this order, the
Lemurs from the same island, some of the species of Marmots, the
remarkable bear dike Mbir&pus of Eastern Tibet, one species of Zebra,
and other Ungulates from Africa.
The distribution of a genus (except of course when the genus is
represented only by a single form) is very generally more exten-
sive than that of a species ; and this may be markedly the case
when there are only some two or three species in a genus. In
genera, moreover, we meet with what is known as discontinuous
distribution, that is, where the distributional area of one or
more species is totally separated from that of others. The best
instance of this occurs in the case of the Tapirs, where we find
one species inhabiting the Malayan Peninsula, and no others
anywhere in the world, with the exception of South America. The
explanation of such an apparently anomalous feature in distribution
is to be found in the past history of the globe, which shows us that
Tapirs once existed in China, Europe, and North America, and,
therefore, indicates that the existing isolated species are the sole
survivors of a group once spread over a large portion of the earth's
surface. In regard to generic distribution it must, however, be
mentioned that this depends to a great extent on the limits which
we are disposed to assign to genera themselves.
As the distributional area of a genus generally exceeds that of
a species, so that of a family, or group of genera, is larger than that
of a single genus ; and similarly the distribution of an order, or
assemblage of families, usually occupies a larger area than that of
a single family. Thus, for instance, the genus Thi/lacimis, re-
presented only by the so-called Tasmanian Wolf or Thylacine, is
now entirely restricted to Tasmania ; but the family Dasyuridte, to
which that genus belongs, ranges all over Australia, while the order
Marsupialia, which includes the Dasynridce, is found both in Aus-
tralia and America, and in past epochs was probably spread over
the entire globe.
A remarkable feature in connection with the distribution of the
terrestrial Mammalia is the circumstance that, with the exception of
certain species introduced by human agency, and small forms which
TERRESTRIAL DISTRIBUTION 95
can easily have been transported on floating timber or other similar
means, they are totally absent from what are known as oceanic
islands — that is islands arising from great depths in the ocean,
mainly composed of coral or volcanic rocks, and showing no signs
of having ever been connected with the existing continents, or the
larger and so-called continental islands. The obvious explanation
of this feature is, that from their total isolation these islands
have never been able to receive a mammalian fauna from the
great continental areas on which mammalian life was probably
first developed.
As an intermediate step between these islands which are
practically void of mammalian life and the continents which teem
with such a variety of forms, are certain larger islands and portions
of continents containing a mammalian fauna more or less markedlj'
distinct from that of the whole of the other regions of the globe.
The best instance of this is Australia, which, with the exception of
one dog — the Dingo — and certain Muridce and Bats, has no mammals
except Monotremes and Marsupials. The latter are, moreover, per-
fectly distinct from those of America, which, if we exclude the islands
in the neighbourhood of Australia, is the only other region which now
possesses any Marsupials at all. Here also we have a ready and full
explanation which accords with all the facts ; since it is evident
that Australia has been isolated from the Asiatic continent from
some very remote geological epoch, at which period it is probable
that Monotremes and Marsupials were the dominant if not the sole
representatives of the Mammalia then existing. Consequently
Australia has never been able to receive an influx of the Eutherian
orders, which have probably swept away all the Marsupials except
the small American Opossums from the rest of the globe. Again,
the large island of Madagascar, which has a fauna of an African type,
but still very markedly different from that of the mainland, may
be considered to have been connected with the latter at a time
when the Eutheria had become the dominant forms, but has been
separated for a sufficiently long period to have enabled a large
number of its species and genera to have become distinct from those
of the adjacent continent. Similarly, there is evidence to show
that South America was probably cut off for a considerable period
from the northern half of the American continent, in consequence
of which its lowly organised fauna of Edentates were enabled to
attain such a remarkable development in the later geological
periods.
In contrast to the mammalian fauna of islands of the preceding-
type is, or rather was, that of the British Islands, Avhich in the
early historic and prehistoric periods was identical with that of
the Continent. This leads to the inference that at a comparatively
late epoch there was a direct land communication between Britain
96 GEOGRAPHICAL DISTRIBUTION
and the Continent, which is shown by geological evidence to have
actually been the case.
The above instances are sufficient to show what an important
influence the date of separation of islands from the adjacent
continents has had upon their existing mammalian fauna, and how
largely the present distribution of mammalian life is bound up with
the past history of our globe. We must, however, not omit to
mention another very important agency of past times which has
likewise had great influence on the present distribution of the
various faunas of the northern hemisphere. This is the so-called
glacial epoch, Avhich took place immediately before the establish-
ment of the present condition of things, and appears to have been
the cause of the extinction of many of the larger mammalian types
which formerly inhabited Europe, and whose retreat to the warmer
regions of the south was apparently cut oft' by the Mediterranean.
Zoological Regions. — Zoologists are now generally agreed in dividing
the land surfaces of the globe into a number of zoological regions or
provinces, characterised by a more or less distinctly marked general
fades of their fauna as a whole. Some of these regions are much more
distinctly defined than the others ; and in the majority of cases
there is a kind of neutral ground or No-man's land at the junction
between any two of these regions. It must also be remembered
that in the Old World proper as we go back in time we find a
gradual assimilation in the mammalian faunas of the different
regions, indicating that originally there was one large fauna of
a generally similar type occupying the greater portion of this
area. Thus we find that Hippopotami, Giraffes, Kudus, Elands,
and other types of Antelopes now restricted to Africa, formerly
extended to Europe and India, while there is also evidence to show
that the group of large anthropoid Apes, now found only in Africa
and the Bornean region, were likewise spread over a large part of
the south-western half of the Old World. Moreover, while at the
present day there is a marked connection between. the mammals of
the northern regions of both the Old and New Worlds, in the
Tertiary period it appears that the fauna of the whole of North
America was much more nearly allied to that of the central regions
of the Old World than is now the case. Thus in the Tertiary
rocks of America we meet with remains of what we are accustomed
to regard as such essentially Old AVorld genera as Horses and
Khinoceroses. On the other hand there are no traces in America
of the existence at any period of Apes, Giraffes, Hippopotami, or
Hyaenas, while that continent has yielded evidence of groups of
Ungulates totally unrepresented in the eastern hemisphere.
The chief zoological regions of the globe, proposed by Mr. Sclater
in 1857, and now recognised by the majority of authorities, are
six in number, and are named as follows. Firstly, the Palaearctic
ZOOLOGICAL REGIONS— PALAZARCTIC 97
region, embracing the whole of Europe, Persia, Northern Arabia,
and all of Asia northward of the line of the Himalaya proper,
Japan, that part of Africa lying northward of the Sahara Desert,
and the oceanic islands of the North Atlantic. Secondly, the
Ethiopian region, which comprises all Africa lying to the south
of the Sahara, the southern part of Arabia, Madagascar, and the
Mascarene Islands. Thirdly, the Oriental or Indian region, which
is taken to include India south of the Himalaya, and to the
north-west as far as Beluchistan, the Malay peninsula, southern
China, Sumatra, Java, Borneo, and the Philippines. Fourthly,
the Australasian region, Avhich is usually defined as being bounded
to the north-west by the deep sea channel lying between Borneo and
Celebes known as Wallace's line, and is taken to include Celebes,
Lumbok, New Guinea, Australia, Tasmania, New Zealand, and the
host of oceanic islands in the South Pacific. Several writers, how-
ever, prefer to regard Celebes and some of the adjacent islands as
representing a transitional Austro- Malayan region. Fifthly, the
Nearctic region, comprising Greenland and North America as far
south as the north of Mexico. And, sixthly, the Neotropical
region, which embraces the remaining portion of the American
continent and the West Indies.
Various minor modifications of this scheme have been proposed.
Thus some writers are disposed to raise India to the rank of a
distinct primary region, while others propose the same for New
Zealand. The Palaearctic and Nearctic regions have a large number
of common types, more especially among the mammals, and Dr. A.
Heilprin l has expressed his opinion that they should be regarded
as a single primary region under the name of the Holarctic. The
same writer would also separate the South Pacific Islands as con-
stituting a Polynesian region.
Minor divisions or sub-regions have also been marked out, but it
will be unnecessary to indicate their limits in the present work.
We may, however, mention the Mediterranean sub-region of the
Palaearctic, which includes the peninsular portion of southern
Europe, North Africa, Asia Minor, Persia, Afghanistan, Beluchistan,
and Northern Arabia, as a good instance of the transition from one
region to another, since its fauna has a mingling of Palaearctic,
Ethiopian, and Oriental types, the former being, however, the
predominant ones.
• Of the chief mammalian types characteristic of these various
regions only a brief sketch can be given in this work.
Pahrardic Region. — The Palaearctic region is of enormous extent,
and includes countries varying greatly in their flora, climate, and
elevation. Thus it embraces the Arctic plains of Siberia, the warm
regions of Italy, Southern France, and Northern Africa, the forest-
1 Distribution of Animals.
7
9 8 GEOGRAPHICAL DISTRIBUTION
clad slopes of the outer Himalaya, and the lofty arid plains of Turk-
estan and Tibet, scorched by a burning sun in summer and chilled by
a still more terrible cold in winter. Its extreme limits in the west
are marked by the Canaries and Azores, and in the east by distant
Japan ; and yet throughout this vast expanse we find a great uni-
formity of life, as exemplified by the large number of British genera
which occur also in Japan. The mammals which are on the whole
the most characteristic of this region are the Sheep and Goats, forming
a section of the great family of Bovidce, nearly all the species of which
are Palsearctic, although we meet with one Goat (Capra) in the
Nilgherries of Southern India, and a Sheep (Ovis) in the Nearctic
region. The Musk Ox (Ovibos) is characteristic of the Palsearctic
and Nearctic regions. At least one species of Camel is characteristic
of this region, and it is not improbable that the second may also
have originated in it. There are a few characteristic types of
Antelopes, such as the Alpine Chamois (Bupicapra), the Saiga of
Tartary, and the Chiru (Panthokps) of Tibet, each of which is
represented by only a single species ; and we miss the host of
Antelopes so characteristic of the Ethiopian region. Deer (Cervus)
are abundant, although by no means confined to this region ; and
the Musk Deer (Moschus), the sole representative of the subfamily
Moschince, is exclusively Palsearctic. Monkeys, as a rule, are absent,
although we meet with one species of Macacus in Northern
Africa and at Gibraltar, and some other types on the southern
border of Tibet. The Moles (Talpa) are mainly Palsearctic,
although one species enters Northern India, while the Desmans
(Myogale) of the Pyrenees and Southern Russia are unknown
beyond the limits of this region. The Water-shrew (Nectogale) is
likewise a peculiar eastern Palsearctic type. Among the Rodents,
the Picas or Tailless Hares (Lagomys) and the Dormice (Mi/oxus)
are essentially Palsearctic forms, only one species of each being found
beyond the limits of the region, and the one extra-Palsearctic species
of Lagomys occurring in the cognate Nearctic region. The Mice and
Rats are represented by the typical genus Mus and other types,
and Hares (Lepus) and one species of Squirrel (Sciarus) are common.
The Carnivora include two species of Bears (Ursus), Wolves and
Foxes (Canis), a Lynx and a few species of Cats (Felis), as well as
numerous weasels (Mustela), and some other types.
Ethiopian Region. — The Ethiopian region is of great interest to
the student of mammals, since it is inhabited by a number of forms
remarkable for their large size. A considerable portion of the area
consists of desert, especially in the north ; but there is also a Avide
extent of grassy plains (veltd), as well as vast tracts of equatorial
forests of great density. Perhaps the most striking feature in the
Ethiopian fauna is the number of Ungulates, both of the Artio-
dactyle and Perissodactyle sections. In the former section we have
ETHIOPIAN REGION 99
the Giraffes (Jjiraffa) represented by one species, which is the type
of a family, and is unknown elsewhere. Equally characteristic are
the Hippopotami, which likewise form the type of a family, while
the Pigs are represented by the Wart-hogs (Phticochozrus) and the
River-hogs, forming an aberrant group of the genus Sus. The Oxen
(Bos) are represented by Buffaloes, but there are no species of true
Oxen or Bison. The Antelopes attain an extraordinary develop-
ment, the number of species being estimated at from eighty to ninety,
which are referred to a large number of genera, although several of
these are more or less ill defined. Most of these genera are peculiar
to this region, but the Gazelles (Gazdla) are also found in the desert
regions of other parts of the Old World, and Oryx ranges into Arabia
and Persia. In contrast to this abundance of Antelopes is the total
absence of the Deer family, or Cerridiv, which are so characteristic
of the Palaearctic and Oriental regions. The Chevrotains or
TragvlidcB are, however, represented by Dorcatherium. 1 In the
Perissodactyle section we may notice the presence of two species
of Rhinoceros, both furnished with two horns, and distinguished from
those of the Oriental region by the absence of incisor and canine
teeth. The Horse family (Equidce) is also represented by several
species, and includes the peculiar group of Zebras, characterised
by their beautifully striped skins. Of other Ungulates the Ele-
phants, which, like the Ehinoceroses, are now peculiar to the
Ethiopian and Oriental regions, have one species, which is widely
different from its Indian congener. The Hyraces are mainly
characteristic of this region, although one species occurs in Syria
and Palestine. The Carnivora include some forms like the Lion,
Leopard, and Jackal, common to the Oriental region, but likewise
include certain peculiar types like the Earth-wolf (Proteles), which
may be regarded as the type of a distinct family, and two species
of Hyaenas, which are referred by some authorities to a distinct genus
(Crocuta). There is also the Hunting-dog (Lycaon), and the peculiar
group of Foxes known as the Fennecs, together with Otocyon. Bears,
Wolves, and true Foxes are absent ; but Civets, etc., are abundant,
although not characteristic of the region. The Primates yield several
very characteristic types, such as the Gorilla and the Chimpanzee
(Anthropopithecus) among the Simiidcr, which, Avith the exception of
the Orangs of Borneo, are the only existing large man-like Apes,
and the group of Dog-faced Baboons (Cijnoceplialus) in the Cereopithe-
cidce. The genus Colobus is also a group of the latter family,
absolutely characteristic of the region. Lemurs, again, occur on
the continent of Africa, but the great development of this group
is in the adjacent island of Madagascar, where several peculiar
genera occur, and where the larger Carnivora and Ungulata are
1 Generally known as Hyomoschus, but first described as an extinct form
under the above name.
ioo GEOGRAPHICAL DISTRIBUTION
absent. These peculiarities of the fauna of Madagascar apparently
point, as previously mentioned, to its separation from the mainland
before the latter was overrun by the larger types, and at a time
when its chief mammals were Lemurs and Insectivores. There
are two genera of Edentates, the Pangolins (Manis), and the Aard-
vark (Orycterqpus), the latter being peculiar.
Although the foregoing groups of mammals are now so
characteristic of the Ethiopian region, it cannot be too strongly
insisted that their restriction to this region is, so to speak, merely
a feature of the present day, and that at a late geological epoch
nearly all the peculiar genera Avere represented in India, and many
of them also in Europe.
Oriental Region. — The third or Oriental region is likewise of very
considerable extent, and is the only one, in addition to the Ethiopian,
which is the home of huge Ungulates, like Elephants and
Rhinoceroses, and the large man-like Apes. A large proportion of
this extensive area is occupied by tropical and subtropical forests
and swamps ; these being especially abundant in Burma, Southern
China, Siam, and the southern ridges of the Himalaya, collectively
constituting the Indo-Chinese sub-region, and also in the Indo-
Malayan sub-region of the Malay peninsula and adjacent islands.
In the third or Indian sub-region, comprising peninsular India, with
the exception of the Carnatic, there are large tracts of open country,
including some of the hottest regions in the world, parts of which
form plains more or less covered with vegetation during the cooler
and rainy seasons, while others are barren rocky table-lands, as in
the Deccan, or arid deserts like those of parts of the Punjab and
Sind. Finally, in the fourth or Cingalese sub-region, represented
by the Carnatic and the island of Ceylon, we find vast areas of
luxuriant forest and jungle. In the north-western desert area of
the Indian sub-region the fauna includes a mixture of Palasarctic and
Ethiopian forms, Avith those characteristic of the Oriental region.
Among the chief features of the mammalian fauna "of this
region we may notice the absence of Hippopotami and Giraffes, the
greatly diminished number of Antelopes, as compared with those
of Africa, and the abundance of Deer and true Pigs. The Antelopes
comprise the two peculiar genera Boselaphus (Nilghai) and the
typical Antilo'pe (Black-buck), each of which is represented by only
a single species, while the Deer belong to the so-called Rusine
group, which is markedly different from that to which the
Palsearctic Red Deer belongs. True Chevrotains (Tragidus) are
peculiar to this region. The Oxen include the true Buffalo,
differing in many respects from the African species of the same
group, and also certain species of true Oxen, such as the Gaour and
Banting, belonging to the Bibovine group, which is confined to this
region. In the Perissodactyla Horses (Equus) are represented
ORIENTAL REGION 101
only by a single species in the desert area of the Indian sub-region,
while the two species of Rhinoceros diner from those of Africa
in being furnished with canines and incisors. The Malayan
Tapir is the only Old World species of its genus. The Indian
Elephant differs, moreover, so markedly from its African ally that
some writers regard the two as types of distinct genera. The
Carnivora include the Lion, Leopard, Jackal, and Hunting-Leopard,
which are common to Africa ; but the Tiger is very characteristic
of this region, although extending northwards into the Palsearctic.
Civets are abundant, comprising some peculiar genera, of which it
will suffice to mention the well known Paradoxurus. Wolves closely
allied to the Palaearctic species occur in Northern India, and there
are also Foxes related to the typical species. The Dog-like animals
which hunt in packs, and are separated by some writers from Canis
under the name of Cyon, occur in the present and the Palsearctic
region. The striped Hyaena is the Indian representative of its genus.
Ratels are common to this and the Ethiopian region, and constitute
the genus Mellivora. The most striking feature in the Carnivorous
fauna of this region, as distinguished from the Ethiopian, is, however,
the presence of Bears, some of which belong to the typical genus
Ursus, while one species is usually generically separated under the
name of Melursus. Among the Rodents we may especially notice
the abundance of the Muridce and Sciuridce. In the former family
Ave have numbers of true Mice (Mus), and also the peculiar genus
Xesocia (Bandicoot-Rat), while in the latter both the true Squirrels
(Sciu rus) and the Flying-Squirrels (Pteromys) attain great develop-
ment. The genus {Pteromys) is, indeed, mainly characteristic of this
region, although in Kashmir and Japan it enters the Palsearctic.
The Bats ai*e very numerous, being represented by all the families,
with the exception of the Phyllostomatidce, or Vampyres, of South
America. Among the Insectivora the genera Tujxiia and Galeo-
pithecus (Flying Lemur) are peculiar to this region, although not
found in India. Finally, in the Primates we have the genera
Macacus and Semnopithems very abundantly represented, although
both also enter the Palsearctic region ; but the Anthropoid types
are confined to the south-eastern half of the region, and include the
Orangs (Simla) of Borneo, and the smaller long-armed Gibbons
(Hylobates), which are abundant in the Malay peninsula, both
genera not being found beyond this region. The Lemurs are much
less abundant than in the Ethiopian region, but they include the
peculiar Tarsier of Sumatra, Borneo, and Celebes (Austro-Malayan
region), which differs so markedly in dentition and structure of
the feet from all other forms that it has been made the type of
a separate family. The Edentates, so poorly represented in the
Old World, include only Pangolins (Manis), which, as we have
already seen, also occur in the Ethiopian region.
102 GEOGRAPHICAL DISTRIBUTION
Australasian Region. — With the fourth or Australasian region we
come to a mammalian fauna so peculiar that we have no difficulty
whatever in defining it from all the other regions of the globe,
although it should be observed that in the Austro-Malayan islands
Ave have a partial mingling of the Australasian and Malayan faunas.
If we exclude Celebes from this region we find that, with the
exception of a Pig in New Guinea, of the Dingo in Australia, of
numerous Mice and Rats (Mv/ridce), and Bats, there are no Eutherian
mammals throughout the area. The mammals of this region are
restricted to the Australian mainland, the island of Tasmania, New
Guinea, and the Aru islands, the whole area of New Zealand
having been totally devoid of mammalian life until introduced by
man. The whole of the Monotremata, constituting the subclass
Prototheria, and all the Marsupials, exclusive of the few outlying
forms ranging into the transitional Austro-Malayan area, and with
the exception of the American family of the OjDossums (Did elphy idee),
are absolutely confined to this region.
Celebes. — The mammals of Celebes — the typical representative
of the Austro-Malayan transitional region or sub-region — include the
peculiar Ape known as Cynopithecus, Tarsius (also Oriental), the
Anoa, and the single species of Babirusa. Several other types of
placental mammals are found in this transitional area, while the
Marsupials are represented by Phalanger and Petaurus.
Neardie Region. — The two remaining regions we have to consider
are comprised in the New World. The first of these is the
Nearctic, which, as already mentioned, has a fauna showing such a
strongly marked relationship to that of the Palasarctic region, that
it has been proposed to unite the two regions. Among types
common to these two regions we may mention closely allied species
of true Deer (Cervus) as exemplified by the Red Deer and the
Wapiti ; the allied Bisons of the two regions ; the Reindeer and Elk
common to both ; as well as nearly related, and in some cases
identical, species of Cats, Lynxes, Bears, Wolves, Foxes, Beavers,
Squirrels, Marmots, and Hares. The Glutton or Wolverene, and the
Musk Ox is also common to the Arctic portions of the two regions.
The Ungulates are very poorly represented, but Ave have, in addition
to the forms already mentioned, one species of the Palaearctic genus
Ovis, namely the Big-horn, and the Prong-buck (Antilocapra), Avhich
is quite peculiar. There are, hoAvever, no Perissodactyla. The
Racoons and Coatis (Procyonidce) constitute a family represented out
of the NeAV World only by the aberrant Cat-Bear (jEIutus) of Nipal.
The characteristic American feline knoAAm as the Puma extends over
this region ; but there are no Edentates, and the Marsupials are
represented only by a single species of Opossum. Rodents are ex-
tremely numerous, and comprise several characteristic types, Avhich
alone would tell us what part of the globe Ave Avere visiting. The
NEOTROPICAL REGION 103
most distinctive are the Pouched Rats {Geomyidce), and the Beaver-like
rodents known as the Hajolodontidce. True Rats and Mice (Mus),
which are represented throughout the Old World, are totally wanting
in the New, where they are replaced by the Vesper-mice, which may
be included in the European genus Oricettis, although often separated
as Hesperomys. This feature alone would seem to justify the dis-
tinction of the Nearctic from the Palsearctic region. The Musquash
(Fiber) is a genus of Nearctic rodents unknown in the Old World.
Among other characteristic genera we may mention, in the Carnivora,
the Skunk (Mephitis) and the American Badger (Tazidea). Primates
are absent from the entire region.
Neotropical Region. — The last of the six main regions is the
Neotropical, including Mexico, South America, and the West Indies.
A very large extent of this area is occupied by forests, which are
described as being denser and more luxuriant than those of any
other part of the globe. Alternating with these forest areas are
the vast grassy plains known in different regions as llanos, savannas,
and pampas. The back-bone of the region is formed by the great
chain of the Andes. Next to the Australasian, this region is
perhaps better characterised by its mammalian fauna than any of
the others. Commencing with the Ungulates, we find a total
absence of Antelopes, Sheep, and Oxen, and also of all Perissodac-
tyles except Tapirs. Deer are, however, represented, although by
peculiar forms (Cariacus) unknown beyond the New World. The
Peccaries (Dicotyles), Avhich are often made the type of a distinct
family, take the place of the Old World Pigs, while the Llamas and
Alpacas (Auchenia) are the substitutes for the Palsearctic Camels.
The Carnivora include several Cats (Felis), among which the Puma
and the Jaguar are the most noticeable ; and there are also Racoons,
Coatis, Foxes, and one species of Bear. Insectivora are totally
wanting ; but the Bats are characterised by the presence of the
Vampyres (Phyllostomatidce), which are almost restricted to this
region. The Rodents likewise include three families unknown
elsewhere, namely the Chinchillas and Viscacha (Chinchillidce), the
Agouties (Dasyproctidce), and the Cavies (Caviidce) ; while a large
number of the Octodontidce are Neotropical, all the other forms
being Ethiopian. In the Primates, again, we have all the forms
quite peculiar to this region, and constituting two families, viz. the
Cebidce or Prehensile -tailed Monkeys, and the Hapalidce, or Mar-
mosets, both of which differ decidedly in their dentition, as well
as in other features, from the Old World Monkeys. Lemuroids
are unknown. Perhaps, however, the mammals which may be
considered as most characteristic of the Nearctic region are the
numerous Edentates, which form three families, mostly confined to
it. These comprise the Bradypodidce or Sloths, which solely
inhabit the forest region ; the Myrmecopliagidce or Anteaters ; and
104 GEOGRAPHICAL DISTRIBUTION
the Dasj/podidce or Armadillos, of which one species has crept
northward as far as Texas. Almost equally characteristic are the
numerous Opossums, the majority of which belong to the genus
Didelplujs. Finally, it should be observed that the West Indies are
distinguished from the rest of the region by the absence of Primates,
Carnivora, and Edentates.
Aquatic Mammals. — Many mammals grouped for the present
purpose as terrestrial pass a great portion of their lives in brooks,
lakes, or rivers, and, being dependent upon such waters for ob-
taining their subsistence, are necessarily confined to their vicinity ;
but the truly aquatic mammals, or those living constantly in the
water, and unable to move their quarters from place to place by
land, are the orders Cetacea and Sirenia, with which may also be
grouped the Seals, forming the Pinniped division of the order
Carnivora.
For the marine Cetacea, animals mostly of large size and
endowed with powers of rapid locomotion, there are obviously no
barriers to universal distribution over the surface of the earth
covered by sea, except such as are interposed by uncongenial
temperature or absence of suitable food. Nevertheless it was
thought some years ago that the fact of a Whale or a Dolphin
occurring in a sea distant from that in which it had usually been
found was sufficient justification for considering it as a distinct
species and imposing a new name upon it. There are now,
however, so many cases known in which Cetaceans from the
northern and southern seas, from the Atlantic and Pacific Oceans,
present absolutely no distinguishing external or anatomical charac-
ters upon which specific determination can be based that the
opposite view is gaining ground ; and, since some species are un-
doubtedly very widely distributed, being in fact almost cosmopolitan,
there seems little reason why many others should not be included in
the same category. The evidence is satisfactory enough in those
instances in which the intermediate regions are inhabited by the same
forms ; — the cases of " continuous areas " of distribution. In those in
which the areas of distribution are apparently discontinuous, there
may be more room for doubt ; but it must not be forgotten that the
negative evidence is here of much less value than in the case of
land animals, since the existence of Cetaceans in any particular part
of the ocean may be easily overlooked. The great Sperm Whale
(Physet&r macrocephalus) is known to be almost cosmopolitan, in-
habiting or passing through all the tropical and temperate seas,
although not found near either pole. At least three of the well-
known species of Korqual (Bahenoptera) of the British coasts are
represented in the North Pacific, on the South American shores,
and near New Zealand, by species so closely allied that it is difficult
to point out any valid distinctive characters, though it may perhaps
AQUATIC MAMMALS 105
be desirable to wait for a more exhaustive examination of a large
series of individuals before absolutely pronouncing them to be
specifically identical There is nothing yet known by which we can
separate the "Humpback Whales" (Megaptera) of Greenland, the
Cape of Good Hope, and Japan. The same may be said of the
common Dolphin of the European seas (Delphinus ddphis) and the
so-called D. bairdi of the North Pacific and D. forsteri of the
Australian seas. The Pilot Whale (Globicephalus melas) and the
Psmdorca of the North Atlantic and of New Zealand are also,
so far as present knowledge enables us to judge, respectively alike.
Many other similar cases might be given. Captain Maury collected
much valuable evidence about the distribution of the larger Cetacea,
and, finding Right Whales (Bidcena) common in both northern and
southern temperate seas, and absent in the intermediate region, laid
down the axiom that " the torrid zone is to the Right Whale as a sea
of fire, through which he cannot pass." Hence all cetologists have
assumed that the Right Whale of the North Atlantic (B. biscayensis),
that of the South Seas (B. australis), and that of the North Pacific (B.
japonka), are necessarily distinct species. The anatomical structure
and external appearance of all are, however, so far as yet known,
marvellously alike, and, unless some distinguishing characters can
be pointed out, it seems scarcely justifiable to separate them from
geographical position alone ; as, though the tropical seas may be
usually avoided by them, it does not seem impossible, or even
improbable, that some individuals of animals of such size and rapid
powers of swimming may have at some time traversed so small a
space of ocean as that which divides the present habitual localities
of these supposed distinct species. If identity or diversity of
structural characters is not to be allowed as a test of species in
these cases, as it is usually admitted to be in others, the study of
their geographical distribution becomes an impossibility.
Although many species are thus apparently of such wide dis-
tribution, others are certainly restricted ; thus the Arctic Right
Whale (Bakrna mysticetus) has been conclusively shown to be limited
in its range to the region of the northern circumpolar ice, and no
corresponding species has been met with in the southern hemisphere.
In this case, not only temperature, but also the peculiarity of its
mode of feeding, may be the cause. The Narwhal and the Beluga
have a very similar distribution, though the latter occasionally
ranges farther south. The common Hyperoodon is restricted to
the North Atlantic, never entering, so far as is yet known, the
tropical seas. Other species are exclusively tropical or austral in
their range. One of the true Whalebone Whales (Neobalcem
in ■trginata) has only been met with hitherto in the seas round
Australia and New Zealand ; and a large Ziphioid (Berardius
arneuxi) only near the last-named islands.
io6 GEOGRAPHICAL DISTRIBUTION
The Cetacea are not limited to the ocean, or even to salt water,
some entering large rivers for considerable distances, and others
being exclusively fluviatile. One species of Platanista is extensively
distributed throughout nearly the whole of the river systems of the
Ganges, Brahmaputra, and Indus, ascending as high as there is
water enough to swim in, but apparently never passing out to sea.
The individuals inhabiting the Indus and the Ganges must therefore
have been for long ages isolated without developing any definite
distinguishing anatomical characters ; for those by which the sup-
posed P. indi was formerly separated from P. gangetica have been
shown by Anderson to be of no constant value. Orcella fluminalis
appears to be limited to the Irawaddy river, and at least two distinct
species of Dolphin belonging to different genera are found in the
waters of the upper Amazon. A Neomeris has been found in the
great Chinese river, the Yang-tsi-Kiang, nearly a thousand miles
from the sea. It is remarkable, however, that none of the great
lakes or inland seas of the world are, according to our present
knowledge, inhabited by Cetaceans. A regular seasonal migration
has been observed in many of the oceanic Cetacea, especially those
inhabiting the North Atlantic, but further observations upon this
subject are still much needed.
The great difference in the manner of life of the Sirenia, as
compared with that of the Cetacea, causes a corresponding difference
in their geographical distribution. Slow in their movements, and
feeding exclusively upon vegetable substances, water-grasses, or fuci,
the Sirenia are confined to rivers, estuaries, or coasts where these
grow, and are not denizens of the open sea, although of course there
is a possibility of accidental transport by the assistance of oceanic
currents across considerable distances. Of the three genera exist-
ing within historic times, one (Manatus) is exclusively confined to
the shores of the tropical Atlantic and the rivers entering into it,
individuals scarcely specifically distinguishable being found both on
the American and the African side of the ocean. The Dusons
(Halicore) is distributed in different colonies, at present isolated,
throughout the Indian Ocean from Arabia to North Australia.
The Bhytina or Northern Sea-Cow was, for some time before its
extinction, limited to a single island in the extreme north of the
Pacific Ocean.
The Pinnipeds, although capable of traversing long reaches of
ocean, are less truly aquatic than the last two groups, always
resorting to the land or to extensive ice-floes for the purpose of
breeding. The geographical range of the various species is generally
more or less restricted, usually according to climate, as they are
mostly inhabitants either of the Arctic or Antarctic seas and adjacent
temperate regions, very few being found within the tropics. For this
reason the northern and the southern species are for the most part
GEOLOGICAL DISTRIBUTION 107
quite distinct In fact, the only known exception is the case of a
colony of the Sea-Elephant (Macrorhinus leoninvs), the general range
of which is in the southern hemisphere, inhabiting the coast of
California. Even in this case a different specific name has been
given to the northern form ; but the characters by which it is
distinguished are not of great importance, and probably, except for
the abnormal geographical distribution, would never have been
noticed. The most remarkable circumstance connected with the
distribution of the Pinnipeds is the presence of members of the
suborder in the three isolated great lakes or inland seas of Central
Asia — the Caspian, Aral, and Baikal ; these forms, notwithstanding
their long isolation, having varied but slightly from species now
inhabiting the Polar Seas.
II. GEOLOGICAL DISTRIBUTION.
Geological Sequence. — In order to understand the geological
distribution, or in other words the distribution in time of mammals,
it is necessary to be acquainted with the chief divisions, or time-
periods, of the strata constituting the crust of the globe. These are
shown in the following table, which commences with the uppermost
or most recent beds and ends with the lowest and oldest.
I. Cainozoic or Tertiary —
1. Pleistocene — River alluvia, etc.
2. Pliocene — Suffolk Crag.
3. Miocene — Hempstead Beds of Hampshire.
4. Eocene — Paris Gypsum and London Clay.
II. Mesozoic or Secondary —
1. Cretaceous — Chalk, Greensands, etc.
2. Jurassic — Oolites and Lias.
3. Triassic — Red Marls, Dolomites, etc.
III. Palaeozoic or Primary —
1. Permian — Beds overlying the Coal.
2. Carboniferous — Coal-measures, etc.
3. Devonian — Old Red Sandstone.
4. Silurian — Wenlock Limestone, etc.
5. Cambrian — Llanberis Slate, etc.
6. Archaean — Gneiss and other schists.
The names in the first column indicate the primary divisions or
life-periods, while those in the second column are the great systems,
each of which is again divided into minor groups, the popular
names of a few of these minor groups being given in the third
column. There are at present no means of arriving at any satis-
factory conclusion as to the absolute length of time indicated by
108 GEOLOGICAL DISTRIBUTION
either the primary or secondary divisions ; but there is little doubt
that the whole of the Tertiary period is only equal to a fraction of
the Mesozoic as regards its duration, while it is probable that
the duration of the Mesozoic epoch was largely exceeded by that
of the Palaeozoic.
Mesozoic Mammals. — The earliest date at which mammals are at
present known is in the upper part of the Triassic period, which
forms the base of the great Mesozoic epoch ; and from this date they
are represented more or less abundantly in various horizons of the
Jurassic and Cretaceous.
The very rapid advances in our knowledge of these forms which
have been made in the last few years, especially in consequence of
the explorations of rich fossiliferous beds in North America, have
not only completely changed the present aspect of the science, but
give such promise for the future, that any sketch which we may
now attempt of this branch of the subject can only be regarded
as representing a transient phase of knowledge. It will be well,
however, to gather together in this place the leading facts now
ascertained with regard to the most ancient forms, as, owing to the
uncertainty of their relationship with any of the existing orders,
they will be most conveniently treated of separately, while the
ascertained facts relating to the geological history of the forms
more nearly allied to those now living will be more appropriately
described under the account of the different groups into which the
class may now be divided.
The remains of mammals which existed anterior to the Tertiary
period hitherto discovered nearly all belong to creatures of very
small size, many of the largest scarcely exceeding the common Pole-
cat or Squirrel. Some are known only by a few isolated teeth,
others by nearly complete sets of these organs, and the majority by
more or less nearly perfect specimens of the rami of the lower jaw.
It is a very curious circumstance that this part of the skeleton
alone has been preserved in such a large number of instances.
Only very rarely has a nearly complete cranium been found ; and
there is no satisfactory evidence of the structure of the vertebral
column of any single individual, and only one known case of a com-
plete limb. 1 The species already described from European strata
are numerous, although the number of genera and species has lately
been reduced. Of these by far the greater number have been found
at a single spot near Swanage in Dorsetshire, in a bed of calcareous
mud only forty feet long, ten feet wide, and averaging five inches in
depth. The marvellous results obtained by the exploration by Mr.
S. H. Beckles of this small fragment of the earth's surface show by
what accidents, as it were, our knowledge of the past history of life
1 The fore limb from S. Africa described as Theriodcsmus, which appears to
be mammalian, and may belong to Tritylodon.
MESOZOIC MAMMALS
109
has been gained, and what may still remain in store where little
thought of at present. A bed, apparently equally rich, has been
discovered in the Jurassic of Wyoming, North America, the contents
of which have been made known by Professor Marsh, while another
fertile source of these remains occurs in the Laramie beds of the
Upper Cretaceous of the United States. 1
jNl The whole of the Mesozoic mammals at present known may be
divided into two great groups, the one characterised by a type of
dentition more or less clearly resembling that found among the
existing Polyprotodont Marsupials, while the other presents an
altogether peculiar modification, recalling in some respects that of
the Diprotodont Marsupials, although differing so decidedly as to
Fig. 24. —Frontal and oral aspects of tlie cranium of Tritylodon longcevus ; from tlie Karoo
system of Basuto-land, South Africa. § natural size. (After Owen.)
show that the owners of this form of dentition cannot be included
in that group.
MuUituberculata. — The name Multituberculata has been proposed
for the group exhibiting the type of dentition last mentioned, and
is generally adopted, although the term Allotheria has been also
suggested. The essential characteristic of the dentition of this group
is the presence of a single scalpriform incisor on each side of the
1 The subjects referred to under this heading are mostly described and figured
in detail in Owen's "Monograph of the Fossil Mammalia of the Mesozoic Forma-
tions," Palxontographical Society's Publications, 1871 ; and in various papers by
Marsh, in the American Journal of Science and Arts, 1878-89. Important con-
tributions to our knowledge of these forms have also been made by Professors Cope
and Osborn, and the reader should especially consult the memoir by the latter
writer on the "Structure and Affinities of the Mesozoic Mammals," published in
the Journal of the Philadelphia Academy (1888), vol. ix.
no
GEOLOGICAL DISTRIBUTION
c
■■■\
lower jaw (Fig. 25) and of one larger incisor, and in some instances
of one or two smaller ones in each premaxilla (Fig. 24). These
incisors are separated by an interval or diastema from the first of
the premolars. The true molars, and in some instances the pre-
molars (Fig. 24), are
characterised by having
longitudinal rows of
tubercles separated by
one or more grooves ;
there being either two
or three of these rows
in the upper molars of
those forms in Avhich
these teeth are known,
Avhile there are, at least
usually, only two in
those of the lower jaw. In other cases the premolars are of a
secant type, with a highly convex cutting-edge, and usually either
serrated or obliquely grooved (Figs. 25, 26). From a certain
resemblance between these secant premolars and those of some of
the smaller Macropoclidce it was at one time considered that we had
in these mammals representatives of Diprotodont Marsupials. The
great difference in the structure of the molar teeth of these forms,
Fig. 25. — The right ramus of the mandible of Plagiaulax
beklesi; from the Purbeek of Swanage. Twice natural size.
i, Incisor ; m, molar ; b, coronoid process ; c, condyle. (After
Owen.)
Fio. 26. — The imperfect right ramus of the
mandible of Plagiaulax minor ; from Swanage.
Four times natural size, p, Premolars ; m,
molars. (After Lyall.)
Fig. 27. — Stereognathus oblithicus. Frag-
ment of jaw with three teeth (a, b, c), in
matrix ; from the Stonesfleld Slate. Natu-
ral size. (After Owen.)
coupled with the circumstance that when the number of upper
incisors is reduced below three it is the second in place of the first
which becomes enlarged and opposed to the incisor of the lower
jaw, seems to prevent the acceptation of this view. Moreover, in
their peculiar structure the molars seem, on the whole, to make a
nearer approximation to the teeth of Ornithorhynchus than to any
other known mammal ; and it has accordingly been suggested that
the Multitubercnlata may really represent an order of Prototheria.
Some support is afforded to this suggestion by certain fragmentary
bones from the Cretaceous of the United States, which are regarded
MESOZOIC MAMMALS in
by Marsh as parts of a coracoid and interclavicle. The peculiar
character of the whole dentition of these forms indicates that if
they are really Prototherians they cannot be regarded as primitive
and ancestral types.
It would be beyond the scope of the present work to describe
in detail, or even to mention the names of all the members of
this group, and it will therefore suffice to refer to a few of the
principal types. Of the forms with tubercular premolars the best
known is the genus Tritylodon (Fig. 24), which occurs typically
in beds of Lower Mesozoic in South Africa, but is also known from
the Trias of Stuttgart. In the Stonesfield Slate, near Oxford,
which belongs to the lower part of the Jurassic system, and is
separated from the Trias by the intervening Lias, a fragmentary jaw
with three teeth (Fig. 27) appears to indicate an allied type, the
teeth having three longitudinal ridges separated by grooves. In
the Purbeck beds of Dorsetshire, forming the top of the Jurassic
system, we find another member of this group, which has been
described as Buhxlon, closely allied to which is Allodun of the
Upper Jurassic of the United States.
The first discovery of the remains of Mesozoic mammals was
made in the Keuper or Upper Trias of the Rhastian Alps in
Bavaria. In 1847 Professor Pleininger of Stuttgart, while sifting
some sand from the Keuper of Diegerloch and Steinenbronn,
found, among an immense mass of teeth, scales, and unrecog-
nisable fragments of skeletons of fish and saurians, two minute
teeth, each with well- defined, enamelled, tuberculated crowns
and distinct roots, plainly showing their mammalian character.
These were considered by their discoverer to indicate a predaceous
and carnivorous animal of very small size, to which he gave the name
of Microlestes antiquus. Subsecpiently Mr. C. Moore discovered in a
bone bed of Rhaatic (topmost Trias) age, filling a fissure in the
Mountain Limestone at Holwell, near Frome in Somersetshire,
various isolated teeth with their crowns much worn, but apparently
including both upper and lower molars and a canine, which are
assigned by Sir R. Owen to Pleininger's genus Microlestes, and
described specifically as M. moorei. Under the name of Hypsi-
prymnopsis rhceticus, Professor Boyd Dawkins described a single tooth
with two roots discovered in the Rhaatic Marlstone at "Watchet in
Somersetshire. Sir R. Owen referred the latter tooth to Microlestes,
and if its describer is right in regarding it as a much worn premolar
of the type of those of Plagiaulax (Fig. 25) there would be evidence
that Microlestes was closely allied to the latter, from the molars
of which those of Microlestes are scarcely distinguishable.
Plagiaulax, of the Dorsetshire Purbeck (Figs. 24, 25), is at once
distinguished from Tritylodon by its secant premolars, which, as already
mentioned, recall those of some of the Macropodidce, although readily
U2 GEOLOGICAL DISTRIBUTION
distinguished by the convexity of the cutting edge and their oblique
grooving. This remarkable and highly specialised type has been the
occasion of one of the most interesting discussions on the inferences
which may be drawn as to the affinities and habits of an otherwise
unknown animal from the structure of a small portion of its organisa-
tion which occurs in the annals of natural history — a discussion
carried on with great ability, ingenuity, and wealth of illustration
on both sides. Dr. Falconer maintained that it was more nearly
allied to the Rat-Kangaroo (Potorous or Hypsiprymnus) than to any
other existing form, and that, as it is known that these animals
feed upon grass and roots, " it may be inferred of Plagiaulax that
the species were herbivorous or frugivorous. I can see nothing in
the character of their teeth," he adds, " to indicate that they were
either insectivorous or omnivorous." Sir R. Owen, on the other
hand, from the same materials came to the conclusion that "the
physiological deductions from the above-described characteristics of
the lower jaw and teeth of Plagiaulax are that it was a carnivorous
Marsupial. It probably found its prey in the contemporary small
insectivorous mammals and Lizards, supposing no herbivorous form
like Stereognathus to have co- existed during the Upper Oolitic
period."
It is impossible here to give at any length the arguments by
which these opposing views are respectively supported, but it may
be indicated that the first-mentioned is strongly countenanced by
the consideration of the following facts : (1) all existing Marsupials
may be divided, so far as their dentition is concerned, into two
groups — (a) those which have a pair of large more or less procumbent
incisors close to the symphysis of the lower jaw, and rudimentary
or no canines (diprotodont dentition), and (b) those which have
numerous small incisors and large pointed canines (polyprotodont
dentition) ; (2) the vast majority of the former group are purely
vegetable feeders, and almost all of the latter are carnivorous or
insectivorous ; and (3) Plagiaulax, so far as its structure is known,
shows an analogy with the former group ; and, as we have no sure
basis for inferences as to the habits of an unknown animal, but the
knowledge of the habits of such as are known, we have no grounds
for supposing that its habits differed from those forms having an
analogous type of dental structure. 1
Allied types, such as Ctenacodon, are also met with in the Upper
1 The whole discussion is contained in the following memoirs : (1) H.
Falconer, " Description of Two Species of the Fossil Mammalian genus
Plagiaulax, from Purbeck," Quart. Journ. Geol. Soc. vol. xiv. 1857 ; (2) R. Owen,
art. " Paleontology," Encyclopaedia Britannica, 8th ed., 1859 ; (3) H. Falconer,
"On the Disputed affinity of the Mammalian genus Plagiaulax," Quart. Journ.
Gcol. Soc. vol. xviii. 1862; (4) R. Owen, "Monograph of the Fossil Mammalia
of the Mesozoic Formation," Palxontographical Society, 1S71.
MESOZOIC MAMMALS u
Jurassic of North America ; and the Plagiavlacidm also persisted
into the lower part of the Eocene division of the Tertiary period ;
Neoplagiavlax being a Tertiary form common to Europe and the
United States, while Liotomus and Ptilodvs are at present known
only from the latter country.
The present group is also represented in the upper Cretaceous
of the United States by Sdemcodon (Mcnisco'essiis in part), Cimoliomys,
etc. Polymastodon, of the Lowest or Puerco Eocene of New Mexico
is the largest known form, and is characterised by the presence
of only one premolar and the elongated molars. The angle of
the mandible is inflected after the Marsupial fashion.
Polyprotodmt Types. — The second type of mammalian dentition
found in the Mesozoic period resembles that occurring among
recent Polyprotodont Marsupials — that is to say there are at
least three lower incisors, the canines are well developed, and the
premolars and molars are cuspidate, the number of the latter reach-
ing in some cases to seven or eight. There has been much dis-
cussion as to the taxonomic position of these forms, and while the
majority of writers admit the Marsupial affinities of at least a
moiety, it has been contended that others indicate distinct ordinal
groups more or less closely allied to the Insectivora. At present,
however, there is no decisive evidence to support such a view.
Important proof of the Marsupial affinity of one of these forms is
afforded by the replacement of the teeth, which appears to be of the
same nature as in the existing Marsupials, that is to say, the last
premolar alone is preceded by a milk-tooth.
The most generalised forms appear to be Dromatherium and
Microconodon, from Lower Mesozoic beds in the United States, of
which enlarged views of the teeth are given in Fig. 4 (1, 2), p.
3 1 . Professor Osborn points out the extremely simple character of
these teeth, and it is quite possible that these forms may prove
to be Prototheria. There are three premolars and seven molars in
the lower jaw of Dromatherium.
A common form in the Purbeck of Dorsetshire is Triconodon
(TriacantJwdoit), in which the formula of the lower teeth is i 3, c 1,
p 4, m 3-4. A lower jaw is shown in
Fig. 28, and an enlarged view of a molar
tooth in Fig. 4 (5). The molar teeth con-
sist of three flattened cones placed in the
same antero- posterior line, those of the
_ li i • Ti t> ■ Fig. 28. — Reversed view of the
upper and lower jaw being alike. Pria- left ramus of the mandible of
COdan, of the Jurassic Of the United States, Triconodon mordax ; from the
is probably inseparable from Triconodon. Pmbeck of Swanage. Natural
T ,, m i n ■ mil nr\\ r size - (After Owen.)
In the genus Phascolotlienurii (rig. 29) of
the Lower Jurassic Stonesfield Slate, the lower teeth may be
classified as i 4, c 1, p 3, in 4, the premolars and molars being
8
ii4
GEOLOGICAL DISTRIBUTION
much alike. The molars approximate to the type of those of
Triconodon, but the anterior and posterior cones are relatively
smaller. Like that of the last-named genus, the mandible of
1
-
Fig. 29. — Inner view of the right ramus of the mandible of Phascolotherium bucklandi ;
from the Stonesfiekl Slate. The outline shows the natural size, i, Incisors (one missing) ; c,
canine ; p, premolars ; m, molars. The mylohyoid groove is seen near the lower border. (After
Owen.)
Phascolotherium is remarkable for the extremely low position of
its articular condyle. In Amphilestes (Fig. 30) of the Stonesfiekl
Slate the molars appear to be of the same general type as those
of Phascolotherium, but are more numerous, although their exact
number cannot be determined. A somewhat different type
of lower molar is displayed by the genus Amblotherium, of the
Dorsetshire Purbeck, to which Amphitherium of the Stonesfield Slate
was probably allied. This type of tooth is shown in Fig. 4 (8, 9,
12) p. 31, and, as there stated, represents that modification of the
tritubercular type known as the tubercular sectorial. The three
primitive tritubercular cusps form what is known as the blade of
the tooth, behind which
there is the talon or
hypocone. A similar
form of molar occurs
in the existing Opos-
sums and Bandicoots.
The number of lower
teeth in Amfohtherium
is i 4, c 1, p 4, m
7-8. Numerous allied
types, such as Achyro-
don and Dryolestes occur in the Upper Jurassic of Europe or the
United States, while from only one side of the jaw being exposed
in each case so-called genera like Stylodon and Sly! a radon have been
formed upon specimens showing the opposite side to that which
is exposed in the types of Amblothenuin and Amphitherium. The
Fig. 30.— Reversed inner view of the left ramus of the
mandible of Amphilestes broderipi ; from the Stoneslield
Slate. Twice natural size. The restoration of the anterior
teeth is conjectural, and the condyle is placed too high.
(After Owen.)
TERTIARY MAMMALS 115
only parallel among existing forms to the excessive number of
molar teeth found in these Mesozoic genera occurs in the Mar-
supial genus Myrmecobius, of which a description is given in a
succeeding chapter. Jaws more or less closely resembling those
described under the names mentioned above are also found in
the uppermost Cretaceous of the United States. A feature com-
mon to these Mesozoic mammals and Myrmecobius and some other
existing forms is the presence of a narrow channel on the inner
side of the mandibular ramus known as the mylohyoid groove
(Fig. 29).
The last type of molar dentition occurring among the Mesozoic
Mammalia is that found in the
lower jaws (Fig. 31), upon which
the genus Spctiacotherium was
established, the upper jaws,
described as Peralestes, being;
, f ,, i ° Fig. 31.— Part of the left ramus of the man
apparently referable to the Same clible, viewed from the outer side, of Spcda-
ailimal. Upper and lower teeth cotherium tricuspidens ; from the Purbeek of
of this form are represented in Swanage " Twice natural size - (After Owen.)
Fig. 4 (6, 7), p. 31, where they are described as typical examples
of the tritubercular type of molars, the upper teeth having one
inner and two outer cusps, and the reverse condition obtaining in
the lower ones. This type of molar presents a marked resemblance
to that found in the existing Insectivorous genus Chrysochloris ; the
number of lower teeth in Spalacotherium is, however, i 3, c 1,
p + m 1 0, by which it is widely distinguished from all the Insect-
ivora. Menacodon, of the Upper Jurassic of the United States,
appears to be allied to Spalacotherium.
Tertiary Mammals. — The more important types of Tertiary
mammals will, as already mentioned, be noticed under the heads
of the groups to which they are severally allied ; but a few general
remarks on this subject may be advantageously recorded in this chap-
ter. In the first place, it may be observed that the comparatively
scanty evidence of mammalian life hitherto yielded by the Cretaceous,
coupled with the number and variety of forms approximating to
the existing groups found even in the lowest Tertiary, indicates a
great imperfection of the geological record. At present, indeed,
we have no decisive evidence of the existence of any members of
the Eutherian subclass previously to the Tertiary; but it can hardly
be doubted that in some part of the world they had made their
appearance before that epoch. The Eutherian mammals of the
lowest Eocene, both in Europe and the United States, are of an
extremely generalised type ; and although many of them approximate
to existing groups, they show such a combination of characters, now
restricted to individual groups, as to indicate that several of the
various orders into which the subclass is now divided were at that
n6 GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION
period very intimately connected. A marked feature of these
early Eutherians is the prevalency of trituberculism in the dentition,
not less noteworthy being the frequent occurrence of pentaclactylism
in the feet, while many of the individual bones were devoid of the
grooves and ridges found in those of later types. By the time
that we reach the upper division of the Eocene period, such as the
horizon of the well-known gypsum of the Paris basin, nearly all the
chief groups of mammals had become clearly differentiated from
one another, although their representatives were usually more
o-eneralised than their existing allies. From this date to the later
geological periods there is a gradual approximation to the types of
mammalian life existing at the present day.
In addition to the features of trituberculism and pentadactyl-
ism so characteristic of the oldest known Eutherians, we may notice
some other points in connection with the earlier types. Thus the
older Tertiary mammals, as we have already stated, had relatively
smaller and simpler brains than the later types, so that a gradual
evolution in this respect may be traced from the Eocene to the
Pleistocene. Again, there is a great tendency among the Eocene
forms to a retention of the typical Eutherian dental formula noticed
on page 25, and also to the absence of an interval, or diastema, in
the dental series. Concomitantly with this feature we may notice
the short crowns and simpler structure of the molar teeth of the
earlier Ungulates as compared with those of to-day, of which details
will be given in a later chapter. Another instance of the more
generalised characters of the earlier mammals is afforded by the
absence or slight development of horns, antlers, and tusks among
the Ungulata. Thus the earlier Khinoceroses were hornless, and
the Deer either without antlers or with antlers of a very simple
kind, while the male Swine were not furnished with the formidable
tusks of the existing Wild Boars. Finally, all, or nearly all of the
mammals, from the lowest Eocene of Rheims present the pecu-
liarity of having a vertical perforation in the astragalus.
The intimate connection existing during the Middle Tertiary
between many families of mammals now widely distinguished from
one another may be more conveniently noted when we come to the
consideration of the families in question.
CHAPTEE V
THE SUBCLASS PROTOTHERIA OR ORNITHODELPHIA
General Characters. — The characters of the Prototheria can at
present only be deduced from the two existing families, since
hitherto no extinct animals which can he referred with certainty
to other divisions of this remarkable and well-characterised group
have been discovered. These two isolated forms, in many respects
widely dissimilar, yet having numerous common characters which
unite them together and distinguish them from the rest of the
Mammalia, are the Ornithorhynchidce and the Echidnidce, both re-
stricted in their geographical range to the Australian region of the
globe. Taken altogether they represent the lowest type of evolution
of the mammalian class, and most of the characters in which they
differ from the other two subclasses tend to connect them with the
inferior, vertebrates, the Sauropsida and Amphibia ; for, though
the name Ornithodelphia owes its origin to the resemblance of the
structure of the female reproductive organs to those of birds, there
is nothing especially bird-like about them.
Their principal distinctive characters are these. The brain has
a very large anterior commissure, and a very small corpus callosum,
agreeing exactly in this respect with the Marsupials. The cerebral
hemispheres, in Echidna at least, are well developed and convoluted
on the surface. The auditory ossicles present a low grade of de-
velopment, the malleus being very large, the incus small, and the
stapes columelliform. The coracoid bone is complete, and articu-
lates with the sternum, and there is a precoracoid (epicoracoid) in
advance of the coracoid, while there is also a large " interclavicle "
or episternum in front of the sternum, and connecting it with the
clavicles. There are also " epipubic " bones. The oviducts (not
differentiated into uterine and Fallopian portions) are completely
distinct, and open, as in oviparous vertebrates, separately into a
cloacal chamber, and there is no distinct vagina. The testes of
the male are abdominal in position throughout life, and the vasa
1 1 8 MONO TREMA TA
deferentia open into the cloaca, not into a distinct urethral passage.
The penis, attached to the ventral Avail of the cloaca, is perforated
by a canal in the greater part of its length, and not merely grooved,
as in reptiles and those birds which have such an organ. The
canal is open at the base and brought only temporarily in contact
with the termination of the vasa deferentia, so as to form a seminal
urethra when required ; but it never transmits the urinary secretion.
This condition is a distinct advance on that of the Sauropsida in
the direction of the more complex development of these parts in
most of the other Mammalia. The ureters do not open into the
bladder, but behind it into the dorsal wall of the genito-urinary
passage. The mammary glands have no distinct nipple, but pour
out their secretion through numerous apertures situated in a cup-
shaped depression of the abdominal skin, forming a mammary
marsupium, especially developed in the females during lactation.
It should be mentioned that, according to the observations of Pro-
fessor Gegenbaur, the mammary glands of the Monotremes are the
simplest found in the entire class. The region of the glands is,
indeed, distinguished from the rest of the abdomen merely by its
thicker layers of muscles. The glands themselves are closely con-
nected with the hair-follicles, and belong to the sudoriparous type,
whereas the glands of all other mammals are of sebaceous origin.
The young are produced from eggs laid by the female parent,
which are meroblastic, like those of birds; that is to say only a
portion of the yolk segments and forms the embryo, the remainder
serving for the nourishment of the latter.
The above are the principal distinguishing characters of the
group, and apply not only to the subclass, but of course equally to
the one order Monotremata, in which the two existing genera are
included. In addition to these more important characters, the
following minor features may also be mentioned.
The scapula differs from that of all other mammals in that the
ridge corresponding to the spine of other forms is situated on the
anterior border instead of in the middle of the outer or dorsal surface.
The humerus is much expanded at its two extremities, and has a very
prominent deltoid crest, and a well-marked entepicondylar foramen.
The dorso-thoracic vertebras are nineteen in number, and have
no terminal epiphyses to their bodies. The tranverse processes of
the cervical vertebrae are of autogenous formation, and remain
suturally connected with the remainder of the vertebra until the
animal is full-grown. Though in this respect they present an
approximation to the Sauropsida (Reptiles and Birds), they differ
from these classes, inasmuch as there is not a gradual transition from
these autogenous transverse processes of the neck (or cervical ribs,
as they may be considered) into the thoracic ribs, for in the seventh
vertebra the costal element is much smaller than in the others,
( )RNITHORH YNCHID. E 1 1 9
indicative of a very marked separation of neck from thorax, not
seen in the existing Sauropsida. The upper ends of the ribs
are attached to the sides of the bodies of the dorsal vertebras
only, and not to the transverse processes. The sternal ribs are
well ossified, and there are distinct partly ossified intermediate ribs.
The cerebral cavity, unlike that of the lower Marsupials or the
Reptiles, is large and hemispherical, flattened below and arched
above, and about as broad as long. The cribriform plate of the
ethmoid is nearly horizontal. The cranial Avails are very thin, and
smoothly rounded externally, and the sutures become completely
obliterated in adult skulls, as in Birds. The broad occipital region
slopes upwards and forwards, and the face is produced into a long
and depressed rostrum. The bony palate is prolonged backwards,
so that the posterior nares are nearly on a level with the glenoid
fossa;. The mandible is without distinct ascending ramus ; the
coronoid process and angle are rudimentary, and the two halves are
loosely connected at the symphysis. The fibula has a broad,
flattened process, projecting upwards from its upper extremity
above the articulation, like an olecranon. In the male there is an
additional, flat, curved ossicle on the hinder and tibial side of the
plantar aspect of the tarsus, articulating chiefly to the tibia, which
supports in the adult a sharp-pointed perforated horny spur, with which
is connected the duct of a gland situated beneath the skin of the back
of the thigh, the function of which is not yet clearly understood. (A
rudimentary spur is found in the young female Oriiithorhynchus, but
this disappears when the animal becomes adult.) The stomach is
sub-globular and simple ; the alimentary canal has no ileo-caecal valve,
or marked distinction between large and small intestine, but has a
small, slender vermiform c?ecum with glandular walls. The liver
is divided into the usual number of lobes characteristic of the
Mammalia, and is provided with a gall-bladder.
In the presence of three distinct bones developed from cartilage
in the shoulder-girdle (viz. scapula, coracoid, and pre- or epi-coracoid)
the Monotremes agree with the Anomodont reptiles (see p. 83),
and with no other representatives of that class. The precoracoid
of the Anomodonts is, however, distinguished by extending upwards
to articulate with the acromial process of the scapula. The
Monotreme humerus is, moreover, strikingly like the corresponding-
bone of many of the Anomodonts and of some of the allied
Labyrinthodont Amphibians.
Family ORXITHORHYNCHIDiE.
Ornithorh/nchus. 1 — Cerebral hemispheres smooth. Premaxillfe
and mandible expanded anteriorly and supporting a horny beak
1 Blumenbach, Voigts Magazin, vol. ii. p. 205 (1800).
1 20 MONO TREMA TA
something like that of a duck, bordered by a naked and very sensitive
membranous expansion. The place of teeth in the adult is supplied
functionally by horny structures, elongated, narrow, and sharp-
edged, along the anterior part of the sides of the mouth, and broad,
flat-topped or molariform behind. Functional molar teeth present
in the young and adolescent condition. Legs short, fitted for
swimming ; feet webbed, each with five well-developed toes armed
with large claws, beyond which in the fore feet the interdigital
membrane is extended. Vertebrae: C 7, D 17, L 2, S 2, Ca 21.
Acetabulum not perforated. Tongue not extensile. Mucous mem-
brane of small intestine covered with delicate, close-set transverse
folds or ridges. Tail rather short, broad, and depressed. Eyes
very small. Fur close and soft.
The Duck-billed Platypus (Platypus anatinus) was the name
assigned to one of the most remarkable of known animals by
Shaw, who had the good fortune to introduce it to the notice
of the scientific world in the Naturalists Miscellany (vol. x., 1799).
In the following year it was independently described by Blumenbach
(Voigts Magazin, ii. p. 205) under the name of Ornitliorhynchus
paradoxus. Shaw's generic name, although having priority to that
of Blumenbach, could not be retained, as it had been used at
a still earlier time (1793) by Herbst for a genus of Coleoptera.
Omithorhynchus is therefore now universally adopted as the scien-
tific designation, although Duck-billed Platypus or Duck-bill may
be conveniently retained as a vernacular appellation. By the
colonists it is called " Water-Mole," but it need scarcely be said,
its affinities with the true moles are of the slightest and most
superficial description. Until the last few years the early stages
of the development of the young were not fully known. It had,
indeed, been repeatedly affirmed, in some cases by persons who
have had actual opportunities of observation, that the Platypus lays
eggs ; but these statements were generally received with scepticism
and even denial. This much-vexed question was, however, settled
by the researches of Mr. W. H. Caldwell in 1884, who found that
these animals, although undoubtedly mammals throughout the
greater part of their structure, are oviparous, laying eggs, which in
the manner of their development bear a close resemblance to the
development of those of the Eeptilia. Two eggs are produced at
a time, each measuring about three-fourths of an inch in its long,
and half an inch in its short, axis, and enclosed in a strong, flexible,
white shell.
The Platypus is pretty generally distributed in situations
suitable to its aquatic habits throughout the island of Tasmania
and the southern and eastern portions of Australia. Slight variations
in the colouring and size of different individuals have given rise to
the idea that more than one species may exist ; but all naturalists
ORNITHORHYNCHin.K
121
who have had the opportunity of investigating this question by the
aid of a good series of specimens have come to the conclusion that
there is but one, and no traces of any extinct allied forms have yet
been discovered.
The length of the animal when full grown is from eighteen to
twenty inches from the extremity of the beak to the end of the tail,
the male being slightly larger than the female. The fur is short,
dense, and rather soft to the touch, and composed of an extremely
fine and close under-fur, and of longer hairs projecting beyond
this, each of which is very slender at the base, and expanded,
Fig. 32. — Platypus or Duck-bill (Omithorhynchus anatinus). From Gould's Mammals of
Australia.
flattened, and glossy towards the free end. The general colour is
deep brown, but paler on the under parts. The tail is short, broad,
and depressed, and covered with coarse hairs, which in old animals
generally become worn off from the under surface. The eyes are
small and brown. There is no projecting pinna or ear-conch. The
mouth, as is well known, bears a striking resemblance to the bill of
a Duck. It is covered with a naked skin, a strong fold of which
projects outwards around its base. The nostrils are situated near
the extremity of the upper surface. There are no true teeth in the
adult, but their purposes are served by horny prominences, or
cornules, two on either side of each jaw — those in the front narrow,
longitudinal, sharp-edged ridges, and those behind broad, flattened,
122 MONO TREMA TA
and molariform. The upper surface of the lateral edges of the
mandible has also a number of parallel fine transverse ridges, like
those on the bill of a Duck. Until 1888 it was thought that true
teeth were totally wanting throughout the life of this animal ; but in
the spring of that year Mr. E. B. Poulton 1 announced the discovery
in an embryo of teeth which were regarded as quite functionless. In
the following year, however, Mr. 0. Thomas 2 was fortunate enough
to find some young skulls with functional teeth in situ, and was thus
enabled to give a detailed account of their structure and of their
relations to the cornules. From these specimens it appears that
the teeth are functional for a considerable part of the life of the
animal, cutting the gum in the usual manner, and, after being worn
down by friction with food and sand, are shed from the mouth
in the same manner as are the milk-teeth of other mammals. The
cornules are developed from the epithelium of the mouth under and
around the teeth, and the hollows found in the middle of them are
the vestiges of the alveoli from which the teeth have been shed.
One of the skulls showed on either side, both above and below, two
completely calcified teeth ; but in another example there were three
teeth on either side of the lower jaw. According to Mr. Thomas's
account, " the teeth themselves are broad, flat, and low-crowned.
The upper ones have each two high, conical, internal cusps, from
which minute ridges run downwards and outwards to the outer
borders of the crowns, where the edge is peculiarly crenulate rather
than cuspidate, in the ordinary sense of the word. On the whole,
the anterior and posterior upper teeth are essentially similar to one
another, except that the former are narrower, and their outer edges
are less markedly crenulated. In the lower jaw there is a greater
difference between the two. The anterior is triangular in outline,
its longest side is placed antero-externally, and its anterior and
postero-external angles have each a high pointed cusp, ridged on
its internal aspect, while the posterior and internal borders are
indistinctly crenulated. The posterior tooth is broadly quadrangular
in outline, with a projecting antero-internal angle. As in the cor-
responding tooth above, there are two cusps on one side, and a series
of crenulations on the other, but they are of course reversed, the
cusps being external and the crenulations internal. The cusps are
high, and connected with transverse ridges running across towards
the internal border."
In trying to find any teeth like those of the Duck-bill among
other known mammals Mr. Thomas considers, as was first suggested
by Professor Cope, that those of the Mesozoic Multituberculata (p. 109)
make the nearest approximation. He adds, however, that " it must
be insisted that the resemblance between the Multituberculate
1 Proceedings of the Royal Society of London, vol. xliii. p. 353 (1888).
- Ibid. vol. xlvi. p. 126 (1SS9).
ORNITHORHYNCHIDM 123
and the Ornithorhynchus teeth is of the most general character,
and that the two are certainly widely separated generically, even if
we do admit that they appear to possess a relationship nearer to
each other than to any other known groups of mammals."
Reverting to the description of the Duck-bill, Ave find that in
the cheeks are tolerably capacious pouches, which appear to be used
as receptacles for food. The limbs are strong and very short, each
with live well-developed toes provided with strong claws. In the
fore feet the web not only fills the interspaces between the toes, but
extends considerably beyond the ends of the long/ broad, and some-
what flattened nails, giving great expanse to the foot when used for
swimming, though capable of being folded back on the palm when
the animal is burrowing or walking on the land. On the hind foot
the nails are long, curved, and pointed, and the web extends only
to their base. On the heel of the male is a strong, curved, sharply
pointed, movable horny spur, directed upwards and backwards,
attached by its expanded base to the accessory bone of the tarsus.
This spur, which attains the length of nearly an inch, is traversed
by a minute canal, terminating in a fine longitudinal slit near
the point, and connected at its base with the duct of a large gland
situated at the back part of the thigh. The whole apparatus is so
exactly similar in structure to the poison-gland and tooth of a
venomous snake as to suggest a similar function, but evidence that
the Platypus ever employs its spur as an offensive weapon has, at
all events until lately, been wanting. A case is, however, related
by Mr. Spicer in the Proceedings of the Royal Society of Tasmania
for 1876 (p. 162), of a captured Platypus inflicting a severe wound by
a powerful lateral and inward movement of the hind legs, which wound
was followed by symptoms of active local poisoning. It is not improb-
able that both the inclination to use the weapon and the activity of the
secretion of the gland may be limited to the breeding season, and
that their purpose may be, like that of the antlers of deer and
many similar organs, for combat among the males. In the young
female the spur is present in a rudimentary condition, but it dis-
appears in the adult of that sex.
The Platypus is aquatic in its habits, passing most of its time in
the water or close to the margin of lakes and streams, swimming
and diving with the greatest ease, and forming for the purpose of
sleeping and breeding deep burrows in the banks, which generally
have two orifices — one just above the water level, concealed among
long grasses and leaves, and the other below the surface. The
passage at first runs obliquely upwards in the bank, sometimes to
a distance of as much as fifty feet, and expands at its termination
into a cavity, the floor of which is lined with dried grass and
leaves, and in which the eggs are laid and the young brought up.
The food consists of aquatic insects, small crustaceans, and worms,
1 24 MONO TREMA TA
which are caught under water, the sand and small stones at the
bottom being turned over with the bill. The creatures appear
at first to deposit what they have thus collected in their cheek
pouches, and when these are filled they rise to the surface and
quietly triturate their meal with the horny plates before swal-
lowing it. Swimming is effected chiefly by the action of the
broad forepaws, the hind feet and tail taking little share in
locomotion in the water. When asleep they roll themselves into
a ball, as shown in the figure. In their native haunts they are
extremely timid and wary, and very difficult to approach, being
rarely seen out of their burrows in the daytime. Mr. A. B.
Crowther, who has supplemented the often quoted observations
of Dr. Bennett upon the habits of these animals in confinement,
says, " They soon become very tame in captivity ; in a few days
the young ones appeared to recognise a call, swimming rapidly
to the hand paddling the water ; and it is curious to see their
attempts to procure a worm enclosed in the hand, which they
greedily take when offered to them. I have noticed that they
appear to be able to smell whether or not a worm is contained in
the closed hand to which they swim ; for they desisted from their
efforts if an empty fist was offered." When irritated they utter a
soft low growl, resembling that of a puppy.
Family Echidnid.e.
Cerebral hemispheres larger and well convoluted. Facial portion
of skull produced into a long, tapering, tubular rostrum, at the
end of which the anterior nares are situated. Rami of mandible
slender, styliform. Opening of mouth small, and placed beloAv the
extremity of the rostrum. No teeth or laterally placed hoimy plates,
though the palate and tongue are furnished with spines. Tongue
very long, vermiform, slender, and protractile. Lining membrane
of small intestine villous, but without transverse folds. Feet not
webbed, but with long strong claws fitted for scratching and
burrowing. The hinder feet with the ends of the toes turned
outwards and backwards in the ordinary position of the animal
when on the ground. Tail very short. Acetabulum with a large
perforation, as in Birds. Calcaneal spur and gland of the male
much smaller than in Ornitliorhynchus. Fur intermixed with strong,
sharp-pointed spines. Terrestrial and fossorial in habits, feeding
exclusively on ants, and recalling in the structure of the mouth and
various other parts relating to their peculiar mode of life the true
Anteaters of the order Edentata.
The Echidnas or Spiny Anteaters constitute a family which
appears in some respects to be less specialised than the Ornitho-
rln/uchidce. According to Mr. 0. Thomas, all the living forms may
ECHIDNID. E
be included in two species, which, with some hesitation, are referred
to two genera — Echidna and Proechidna (Acanthoglossus).
Echidna} — In Echidna there are five toes, all of which are
provided with claws, those of the fore feet being broad, slightly
curved, and directed forwards, while the posterior ones are slender,
more curved, and inclined outwardly. The beak is about as long
as the rest of the head, and either nearly straight, or slightly curved
upwards, while the palate is comparatively wide, and but slightly
vaulted. The number of the vertebrae is C 7, D 16, L 3, S 3, Ca 12.
The one existing representative of the genus (E. aculeata) occurs in
Xew Guinea, Tasmania, and Australia.
So much variation is displayed by this animal, that it has been
divided into several species, but the latest researches tend to show
that these variations cannot be regarded as indicating more than
races, of which there are three well-marked types.
The first race, or variety, has been termed the Port Moresby
Echidna, and is only known from that Papuan locality. It is
distinguished from the typical form by its smaller size, by the
shorter spines on the back, which admit of the fur being seen, and
by the more spinous covering of the head, belly, and limbs, as well
as by the lighter skull and relatively larger beak.
The typical variety is confined to the Australian mainland, and
is of medium size. The spines of the back are very long and stout,
often reaching a length of two inches, and almost completely con-
cealing the hair. The colour of these spines varies from yelloAV at
the roots to black at the tips, but some may be altogether yellow.
The hair of the back is black or dark brown in colour, but it may
be occasionally absent, or in the region of the loins may exceed the
spines in length. The limbs and under surface of the body are
covered with dark brown hair, thinly interspersed with short spines ;
and the hair of the face is of the same general hue as that of the
body. The skidl has a slender rostrum and a flat and narrow
brain-case.
In the third or Tasmanian race, which is confined to Tasmania,
the average size is somewhat larger than in the typical form. The
most characteristic feature is, however, the shortness of the spines
of the back, which in the greater part of that region are almost or
quite concealed by the hairs. The hairs of the back are dark
brown, those of the under surface and sides of the head being
generally rather paler. There is often a white spot on the chest.
Very frequently there is a difference in the proportionate lengths
of the hinder claws from those of the typical race. In the skull
the beak is comparatively short and stout, and the brain-case large
and wide.
Echidnas are usually found in rocky districts, and more especially
1 Cuvier, Tableau EUmentairc d'Hist. Nat. p. 143 (1798).
126
MONOTREMATA
in the mountains. In a wild state they live mainly on ants. Speci-
mens have been brought to this country and kept in the Zoological
Society's Gardens ; and in captivity they will readily eat eggs, and
bread-and-milk. They are able, however, to endure long fasts, an
individual having been known to go without food for upwards of a
month.
These animals seem to be mainly of nocturnal habits, and if
brought out during the day-time appear to be sluggish and stupid,
crouching to the ground with the head between the legs, and thus
presenting a mass of spines to an enemy. They burrow rapidly in
soft ground, sinking directly downwards, and not going head for-
wards. A specimen placed on a large chest of earth containing
plants reached the bottom in less than two minutes ; and it is said
that the muzzle assists in the work of burrowing.
Proechidna. 1 — The one known representative of the genus
Proechidna (Fig. 33) attains dimensions about equal to those of
Fio. 33. — The Three-toed Echidna (Procchihia Iruijnii). From Gervais.
the largest race of Echidna aculeata. The skull is less depressed
than in the latter, with the anterior portion of the palate very
concave, and the deflected beak nearly twice the length of the
remainder of the skull. As a rule, there are only three claws to
each foot ; but the first and fifth digits are represented by several
phalanges, and one instance is known where there are five complete
claws on the anterior and four on the posterior feet. There are
two more vertebra? in the dorsal and lumbar region than in
Echidna.
The head and body are covered with a thick coat of hair,
among which there are a number of short spines in the region of
the back, which are much less numerous than in the typical race of
the last species. The colour of the fur is generally dark brown or
black, but the head may be almost white ; and the spines are
usually entirely white, although in certain cases they may be brown
at the root.
1 Gervais, Osteogmphie des Monotremes, p. 43 (1877).
ECHIDNIDsE 127
This species is known only from New Guinea, the recorded
specimens being from the north-western regions of that country. It
inhabits rocky ground, and dwells chiefly in the mountains, the
specimens which were first described having been obtained at an
elevation of about 3500 feet above the sea level. The Papuans capture
it by digging trenches in the ground to a depth of about a yard, by
which means they generally come upon its runs.
Fossil Species. — Remains of a species of Echidna of very much
larger size than the existing forms have been obtained from the
cave-deposits of New South Wales, which appear to be of Pleisto-
cene age. This species was named Echidna oweni by the late Mr.
Krefl't, but was subsequently called E. ramsayi by Sir R. Owen.
In referring this species to the genus Echidna, that term must be
regarded as including Proechidna.
CHAPTEE VI
THE SUBCLASS METATHERIA OR DIDELPHIA
General Characters. — The Metatheria or Didelphia are represented at
present by numerous species, presenting great diversities of general
appearance, structure, and habits, although all united by many
essential anatomical and physiological characters, which, taken
altogether, give them an intermediate position between the Proto-
theria and the Eutheria.
Although the striking differences in external form, in many
anatomical characters, and in mode of life of various animals of this
section might lead to their division into groups equivalent to the
orders of the Eutheria, it is more convenient on the whole to adhere
to the usual custom of treating them all as forming one order called
Marsupialia, 1 the limits of which are therefore equivalent to that
of the subclass. The more essentially distinctive characters are as
follows.
In the structure of the brain and the presence of epipubic bones
they agree with the Prototheria, while in the structure of the ear-
bones and the shoulder- girdle and the presence of teats on the
mammary glands they resemble the Eutheria, the reproductive
organs belonging to neither one nor the other type, but having a
special character representing an intermediate grade of develop-
ment. The ureters open into the base of the bladder. The
oviducts are differentiated into uterine and Fallopian portions, and
open into a long and distinct vagina, quite separate from the cystic
urethra. The penis is large, but its crura are not directly attached
to the ischia. The spongy body has a large bifurcated bulb. The
young are born in an exceedingly rudimentary condition, and are
never nourished by means of an allantoic placenta, but are trans-
ferred to the nipple of the mother, to which they remain firmly
1 For the detailed characters of all the genera and species of Marsupials the
reader should consult the British Museum Catalogue of Marsupialia and Afono-
tremata, by Old field Thomas, 1888.
GENERAL CHARACTERS 129
attached for a considerable time, nourished by the milk injected
into the month by compression of the muscle covering the
mammary gland. They arc therefore the most typically mam-
malian of the whole class. The nipples are nearly always concealed
in a fold of the abdominal integument or " pouch " (marsupinm)
which serves to support and protect the young in their early
helpless condition.
Entering more fully into the characters of the subclass, which
are also those of the order Marsupialia, it may be observed that the
brain is generally small in proportion to the size of the animal, and
the surface-folding of the cerebral hemispheres, though well marked
in the larger species, is never very complex in character, and is
absent in the medium-sized and smaller species. The arrangement
of the folding of the inner wall of the cerebrum differs essentially
from that of all known Eutheria, the hippocampal fissure being
continued forward above the corpus callosum, which is of very
small size. The anterior commissure is, on the other hand, greatly
developed.
The teeth are always divisible, according to their position and
form, into incisors, canines, premolars, and molars ; but they vary
much in number and character in the different families. Except in
the genus Phascolomys, the number of incisors in the upper and
lower jaws is never equal. The true molars are very generally four
in number on either side of each jaw. The chief peculiarity in the
dentition lies, however, in the mode of succession. Thus there is no
vertical displacement and succession of the teeth, except in the case
of a single tooth on either side of each jaw, which is always the
hindermost of the premolar series, and is preceded by a tooth
having more or less of the characters of a true molar (see Fig. 34);
this deciduous tooth
being the only one
comparable to the
" milk-teeth " of the
diphyodont Eu-
theria. In some
cases (as in Poto-
rous) this tooth re-
tains its place and
•fi-mfti'nn until thp FlG- 3i '~~ Teeth of Upper Jaw of °P 0Ssum (Didelphys mar-
iuntLiou Liiiuii Liie mvia ^ all of which are uncn anged, except the last premolar,
animal has nearly, the place of which is occupied in the young animal by a molari-
if not Ollite attained form tooth, represented in the figure below the line of the other
its full stature, and
is not shed and replaced by its successor until after all the other
teeth of the permanent series, including the posterior molars, are
fully in place and use. In others, as the Thylacine, it is very
rudimentary in form and size, being shed or absorbed before any
9
i *> ME TA THERIA
of the other teeth have cut the gum, and therefore quite function-
less. It must further be noted that there are some Marsupials,
as the Wombat, Myrmecobius, and the Dasyures, in which no such
milk-tooth, even in a rudimentary state, has yet been discovered,
possibly in some cases from want of materials for observation at
the right stage of development.
Epipubic or marsupial bones are present in both sexes of nearly
all species. In one genus alone, Thylacinus, they are not ossified.
The number of dorso-lumbar vetebra? is always nineteen, although
there are some apparent exceptions caused by the last lumbar being
modified into a sacral vertebra. The number of pairs of ribs is
nearly always thirteen. The tympanic bone remains permanently
distinct. The carotid canal perforates the basisphenoid. The
lachrymal foramen is situated upon or external to the anterior margin
of the orbit, and there are generally large vacuities in the bony
palate. The angle of the mandible is (except in Tarsipes) more or
less inflected. The hyoid bones have always a peculiar form,
consisting of a small, more or less lozenge -shaped basi-hyal, broad
cerato-hyals, with the remainder of the anterior arch usually
unossified, and stout, somewhat compressed thyro-hyals. There are
two anterior venae cava?, 1 into each of which a "vena azygos "
enters. In the male the testes are always contained in a scrotum,
which is suspended by a narrow pedicle to the abdomen in front of
the penis. The vasa deferentia open into a complete and continuous
urethra, which is also the passage by which the urine escapes from
the bladder, and is perfectly distinct from the passage for the feeces,
although the anus and the termination of the urethro-sexual canal
are embraced by the same sphincter muscle. The glans is often
bifurcated anteriorly. In the female the oviducts never unite to
form a common cavity or uterus, but open separately into the
vagina, which at least for part of its course is double. The
mammae vary much in number, but are always abdominal in
position, having long teats, and in most of the species are more
or less enclosed in a fold of the integument forming a pouch
or marsupium, though in some this is entirely wanting, and the
newly -born, blind, naked, and helpless young, attached by their
mouths to the teat, are merely concealed and protected by the
hairy covering of the mother's abdomen. In this stage of their
existence they are fed by milk injected into their stomach by the
contraction of the muscles covering the mammary gland, the
respiratory organs being modified temporarily, much as they are
permanently in the Cetacea — the elongated upper part of the
larynx projecting into the posterior nares, and so maintaining a free
communication between the lungs and the external surface
1 Except in Petaurus (Belidcus) brcviceps (Forbes, Proc. Zool. Soc. 1881,
p. 188).
DISTRIBUTION
131
independently of the mouth and gullet, thus averting the danger of
suffocation while the milk is passing down the latter passage.
Distribution. — The existing species of Marsupials are, with the
region,
forming
->v
the chief
Fig. 35. — Front view of skull of Sarcophilus ursinas, showing polyprotodont and carnivorous
dentition (Quart. Journ. Geol. Soc. vol. xxiv. p. 313).
exception of one family (the Didelphyidce), limited in geographical
distribution to the Australasian
mammalian fauna of Australia,
New Guinea, and some of the
adjacent islands. The Didel-
phyides are almost purely Neo-
tropical, one or two species
ranging northwards into the
Nearctic region. Fossil re-
mains of members of this
family have also been found in
Europe and America in strata
of the Eocene and early Mio-
cene periods ; and it is probable
that at least many of the poly-
protodont Mesozoic mammals
noticed in Chapter IV. are
referable to the Marsupialia.
Classification. — In dividing
the Marsupials into minor
groups, it may be observed
that one of the most obvious
distinctive characters among
them is derived from the form
Fig. 36. — Front view of skull of Koala (Phas-
colarctics cinereus), showing diprotodont and
herbivorous dentition (Quart. Journ. Geol. Soc.
vol. xxiv. p. 313).
and arrangement of the teeth.
1 Including the transitional Austro-Malayan region.
1 32 MARSUPIALIA
In certain species, as the Opossums, Dasyures, and Thylacine,
the incisors are numerous, small, and subequal in size, and the
canines large, as in the typical placental Carnivores (Fig. 35).
To these the term " polyprotodont " is applied, and they are all
more or less carnivorous in their habits. In others the central
incisors are very prominent, and the lateral incisors and canines
absent or subordinate in function (Fig. 36). These are called
" diprotodont," and they are all wholly or in great part vegetable
feeders. In one group of these, the Wombats, there are but two
incisors above and the same number below ; but all the others, in-
cluding the Kangaroos, Koalas, and Phalangers, have two functional
incisors below and as many as six above, three on each side, but
of these the first or central pair is the most fully developed.
Some hesitation has frequently been expressed as to whether the
Polyprotodont and Diprotodont types are entitled to constitute
distinct primary groups, owing to the presence of syndactylism
among the Peramelidte in the former, as well as in the latter ; but if
Mr. 0. Thomas is right in regarding this feature as acquired
independently in the two groups we may safely adopt such a
division. Taking various combinations into consideration, the
existing Marsupials readily group themselves into six very natural
families, the leading characters of which may be summarised as
follows : —
Order Marstjpialia.
A. Polyprotodontia. — Incisors numerous, small, subequal. Canines
larger than the incisors. Molars with sharp cusps.
a. Incisors f-. Hind feet with the four outer toes subequal,
distinct, and a well-developed opposable hallux. Didel-
phyid(B.
ft. Incisors |. Hind feet with four outer toes distinct, Hallux
small or rudimentary, rarely opposable. Dasyuridce.
y. Incisors ^ ~ . Hind feet long and narrow. Fourth toe
larger than the others. Hallux rudimentary or absent.
Second and third toes very slender, and united in a
common integument (syndactylous). Peramelidc.
B. Diprotodontia. — Incisors not exceeding § , usually f, but occasion-
ally \. Central (first) upper and lower incisors large and
cutting. Upper canines generally, and lower invariably, absent
or small. Molars with bluntly tuberculated or transversely
ridged crowns.
a. Teeth with persistent pulps. Incisors \, large, scalpriform,
with enamel on the outer surface only. No canines.
Hind feet with four subequal outer toes, partially
syndactylous, and with rudimentary hallux. Phascolo-
myidce.
DIDELPHYID.-E
'33
B. Teeth rooted. Three upper incisors and a canine. Hind
limbs not disproportionately large. Feet syndactylous,
broad, with tour subequal outer toes, and a huge
opposable hallux. l'lt«l<uitjerid<r.
y. Teetli rooted. Three upper incisors, and frequently a
canine. Hind limbs disproportionately large, with
syndactylous feet as in Peramelidcc. Macropodidce.
Suhorder Polyprotodontia.
The loading characters of this group are given in the foregoing
schedule. This group is the only one represented at the present
day, and so far as we know also in past epochs, beyond the confines
of the Australasian region and adjacent islands.
Family Didelphyid^.
Dentition : i -f , c ^, p
35
m ^ • total 50. Incisors very small
and pointed. Canines large. Premolars Avith compressed pointed
crowns. Molars with numerous sharp cusps. The last premolar
preceded by a deciduous multicuspidate milk-molar, which remains in
place until the animal is nearly adult (Fig. 34). Limbs of moderate
development, each with five complete and distinct toes, all of which
are provided with short, compressed,
curved, sharp claws of nearly equal
size, except the first toe of the hind
foot or hallux (Fig. 37), which is large,
widely separable from the others, to
which it is opposed in climbing, and
terminates in a dilated rounded ex-
tremity, without a nail. Tail gener-
ally long, partially naked and prehen-
sile. Stomach simple. Caecum of
small or moderate size. Pouch gener-
ally absent, sometimes represented by
two lateral folds of the abdominal
integument, partially covering the
teats, rarely complete. Vertebrae :
C 7, D 13, L 6, S 2, C 19-35.
The Didelphyidce, or true Opos-
sums, differ from all other existing
Marsupials in their habitat, being-
peculiar to the American continent.
They are mostly carnivorous or insectivorous in their diet, and
arboreal in habits.
Opossums occur throughout the greater part of the American
Fig. 37.— Skeleton of th e right hind
foot of the Virginian Opossum (Didelphys
inarsupialis).
134 MARSUPIALIA
continent, ranging from the United States to Patagonia, the greater
number of species being found in the warmer regions. In South
America the opossums take the place of the Eutherian Insectivora,
and the sharp cusps on their teeth are admirably adapted for crushing
the insects on which they mainly subsist.
Chironectes. 1 — The family comprises two genera only, namely
Diddphys, containing all the species, with the exception of the curious
Yapock, which forms by itself the genus Chironectes, and is distin-
guished from all other Opossums by its webbed feet, non-tuberculated
soles, and peculiar coloration. Its ground colour is light gray, with
four or five sharply-contrasted brown bands passing across its head
and back, and thus giving it a very peculiar mottled appearance.
It is almost wholly aquatic in its habits, living on small fish,
crustaceans, and water insects. Its range extends from Guatemala
to southern Brazil.
Didelphys. 2 — The type genus Didelphys is a very large one, con-
taining, according to Mr. 0. Thomas, twenty-three existing species.
It may be divided into five groups, or sub-genera, all of which have
received distinct names. The typical group is represented only by
the common or Virginian Opossum {p. marsupial is), of which the
numerous varieties have received separate specific names. This
species is of large size, with a long, scaly, prehensile tail, and long
bristle-like hairs mingled with the fur. The pouch is complete.
It ranges over all temperate North America, and is also found in
central and tropical South America, where it is commonly known
as the Crab-eating Opossum. This animal is extremely common,
being even found living in the towns, where it acts as a scavenger
by night, retiring for shelter by day upon the roofs of the houses or
into the sewers. The female produces in the spring from six to
sixteen young ones, which are placed in her pouch immediately
after birth, and remain there until able to take care of them-
selves.
The second or Metachirine group includes three species found
all over the tropical parts of the New World. They are of medium
size, with short close fur, very long, scaly, and naked tails, and
less developed ridges on their skulls than in the type species. As
a rule there is no pouch adapted to carry the young, which
commonly ride on their mother's back, holding on by winding
their prehensile tails round hers. The Philanderine group is
closely allied to the preceding, but is readily distinguished by the
woolly hair, and the brown streak down the middle of the face.
The Woolly Opossum (D. lanigera), which is represented in the
accompanying woodcut (Fig. 38) carrying its young in the fashion
mentioned above, is one of the two species of this group. In the
1 Illiger, Prod. Syst. Mamm. ct Avcs, p. 76 (1811).
- Linn. Syst. Nat. Ed. 12, vol. i. p. 71 (1766).
DIDELPHYID.E
135
fourth or Micouri ine group the numerous species are all smaller
than in the preceding groups, and have short and close hair, and
no dark streak down the face. The best known species is the
Murine Opossum (D. murina), little larger than a House-Mouse,
and of a blight i*ed colour, which is found as far north as central
Mexico, and extends thence right down to the south of Brazil. The
last or Peramyne group contains several extremely shrew-like
species, of very small size, with short, hairy, and usually non-pre-
hensile tails, not half the length of the trunk, and with wholly
unridged skulls. The most striking member of the group is the
Three-striped Opossum (D. americana), from Brazil, which is of a
reddish-gray colour, with three clearly-defined deep-black bands
■0P ! ,,'• ^ -
Fio. 3S. — The Woolly Opossum (Diddphys lanigera).
down its back, very much as in some of the striped mice of
Africa.
The numerous fossil species of Opossum found in the Upper
Eocene and Lower Miocene of Europe are of especial interest from a
distributional point of view, since they indicate how the Opossums of
America may have been connected with the Australian Marsupials.
These forms were originally referred to Diddphys, but have been
subsequently described as Peratherium and Amphiperatherium. The
characters of the molar teeth on which these genera are based do
not appear to be sufficiently important to justify their separation
from Diddphys. Allied forms occur in the Tertiaries of North
America, which were originally described under the name of Her-
petotherium, but have been subsequently referred to Peratherium.
Kemains of many of the existing species of Opossum are found in
a fossil condition in the Pleistocene cave-deposits of Brazil.
!j6
MARSUPIALIA
Family DasyuridtE
Dentition : i j^, c \,p and m numerous, variable. Incisors small ;
canines well developed ; molars with pointed cusps. Limbs equal.
Fore feet with five subequal toes terminating in claws. Hind feet
with the four outer toes well developed, and distinct from each
other and bearing claws ; the first (or hallux) clawless, generally
rudimentary, sometimes entirely wanting. Stomach simple. No
csecum. Predatory carnivorous or insectivorous animals, inhabit-
ants of Australia, Tasmania, and the southern parts of New Guinea
and some of the adjacent islands. The aberrant genus Myrmecobius,
though clearly a member of this family, is so sharply distinguished
Fig. 39.— The Thylacine (Thylacinw cynoceplmlus).
from all the others as to render a division into two subfamilies
necessary.
Subfamily Dasyurinse. — This comprises the more typical Dasy-
nridce, in which the premolars and molars never exceed the normal
number of seven on either side of each jaw, and in which the tongue
is not specially extensile.
Thylacinus. 1 — Dentition : i f, c \-,p%, m| = 46. Incisors small,
vertical, the outer one in the upper jaw larger than the others.
Summits of the lower incisors, before they are worn, with a deep
transverse groove dividing them into an anterior and a posterior cusp.
Canines long, strong, and conical. Premolars separated from one
another by intervals, with compressed crowns, increasing in size
from before backwards. True molars in general characters re-
1 Temminck, Monographies de MammaJogic, vol. i. p. 60 (1827).
DASYURWsE
137
sembling those of Dasywus, but of more simple form, the cusps
being not so distinct nor sharply pointed. Milk-molar very small,
and shed before the animal leaves the mother's pouch. Humerus
with an entepicondylar foramen. General form very Dog-like.
Head elongated. Muzzle pointed. Ears moderate, erect, triangular.
Fur short and closely applied to the skin. Tail of moderate length,
thick at the base and tapering towards the apex, clothed with short
hail-. Hallux (including the metacarpal bone) wanting. Vertebrae :
C 7, D13, L 6, S 2, C 23. Marsupial bones represented only by
small unossified fibro-cartilages.
The only known existing species of this genus, T. cynocephalus
(Fig. 39), though smaller than a common Wolf, is the largest preda-
ceous Marsupial at present living. It is now entirely confined to the
island of Tasmania, although fragments of bones and teeth found in
caves afford evidence that a closely allied species once inhabited the
Australian mainland. The general colour of the Thylacine is
Fig. 40.— Right lateral aspect of the skull of the Thylacine.
grayish brown, but it has a series of transverse black bands on the
hinder part of the back and loins, whence the name of "Tiger"
frequently applied to it by the colonists. It is also called " Wolf,"
and sometimes, though less appropriately, " Hyama." Owing to
the havoc it commits among the sheepfolds, it has been nearly
exterminated in all the more settled parts of Tasmania, but still
finds shelter in the almost impenetrable rocky glens of the more
mountainous regions of the island. The female produces four
young at a time. The pouch opens backwardly, and there are four
mammae. The figure of the skull exhibits the peculiar Dog-like
form so characteristic of the genus.
Sarcophilus} — Dentition : i -*-, c \, p f , m |-. Upper incisors nearly
equal, and placed vertically, the first not differentiated from the
rest. Premolars rounded and closely crowded between the canine
and molars, with broad crowns ; molars broad and heavy, the last
one without a distinct hind talon. Form thick and powerful ;
1 F. Cuvier, Hist. Nat. des Mammiferes, iv. (1837).
133 MARSUPIAL1A
head disproportionately large for the body ; muzzle sbort and
broad ; ears broad and rounded ; tail of moderate length, and
evenly hairy. Hallux wanting ; soles of feet naked, without defined
pads. Humerus with entepicondylar foramen.
This genus is now represented only by a single species
(S. ursinus) found in Tasmania, where, from its ferocious and des-
tructive habits, it is commonly known under the name of the " Devil."
A front view of the skull is shown in Fig. 35.
The prevailing colour of this animal is black, and the size about
equal to that of an English Badger ; its habits are fossorial, and it
is very destructive to sheep. On account of the similarity in the
number of its teeth this genus has been generally included in the
next one, but in the structure of the teeth it is much nearer to
Thylacinus. An extinct species is found in the Pleistocene deposits
of the mainland of Australia.
It may be observed that the two premolars missing from ' the
typical series of four in this and the next genus are the second and
the fourth ; the fourth milk-molar being likewise absent. In
Thylacinus and other Polyprotodonts with three premolars it is the
second that is missing.
Dasyurus. 1 — Dentition : i -J, c \, p f , m -f- ; total 42. Upper
incisors nearly ecpial, and placed vertically ; first slightly longer,
narrower, and separated from the rest. Lower incisors sloping
forwards and upwards. Canines large and sharply pointed. Pre-
molars with compressed and sharp-pointed crowns, and slightly
developed anterior and posterior accessory basal cusps. True
molars with numerous sharp-pointed cusps. In the upper jaw the
first three with crowns having a triangular oral surface, the fourth
small, simple, narrow, and placed transversely. In the lower jaw
the molars more compressed, with longer cusps ; the fourth not
notably smaller than the others. Form viverrine. Ears long and
narrow, prominent, and obtusely pointed. Hallux rudimentary, or
absent ; its metatarsal bone always present. Tail long and well
clothed with hair. Humerus without an entepicondylar foramen.
Vertebra? : C 7, D 13, L 6, S 2, C 18-20.
The Dasyures are small Civet-like animals with a gray or brown
pellage profusely spotted with white ; they are mostly inhabitants
of the Australian continent and Tasmania, where in the economy of
nature they take the place of the smaller predaceous Carnivora, the
Cats, Civets, and Weasels of other parts of the world. They hide
themselves in the daytime in holes among rocks or in hollow trees,
but prowl about at night in search of the small living mammals
and birds which constitute their prey. The species are not numer-
ous, and include D. maculatus, about the size of a common Cat,
inhabiting Tasmania and the southern part of Australia ; D. viver-
1 Geoffroy, Bull. Soc. Philom. vol. i. p. 106 (1796).
DASYURIDAZ 139
rinus, Tasmania and Victoria; P. geoffroyi, nearly all Australia;
D. hallucatus, North Australia ; D. albopunctatus, New Guinea.
Remains referred to 1). vivernnus occur in the Australian Pleis-
tocene deposits.
Phascologale} — This genus comprises a considerable number of
small Marsupials, none of them exceeding a common Rat in size,
differing from the Dasyures in possessing an additional pre-
molar — the dentition being i |, c \,p f, m £ ; total 46, — and having
the teeth generally developed upon an insectivorous rather than a
carnivorous pattern, the upper middle incisors being larger and
inclined forwards, the canines relatively smaller, and the molars
with broad crowns, armed with prickly tubercles. The muzzle is
pointed. Ears moderately rounded and nearly naked. Feet broad
and short, Fore feet with five subequal toes, having compressed,
slightly curved, pointed claws. Hind feet with the four outer toes
subequal, having claws similar to those in the fore feet ; the hallux
always distinct and partially opposable, though small and nailless.
Tail long, very variable in its covering, being either bushy, crested,
or nearly naked. Pouch represented merely by a few folds of skin.
Mamma? varying from four to ten in number. The food of these
animals is almost entirely insects ; some species pursuing their prey
among the branches of trees, while others are purely terrestrial.
They are found throughout Australia, and also in New Guinea and
the Aru and some of the adjacent islands.
P. cristicaudata, a species with a thick compressed tail orna-
mented upon its apical half with a crest of black hair, differs from the
others by the very reduced size of the fourth premolar in the upper,
and its complete absence in the lower jaw, thus forming an interest-
ing transition in dentition towards Dasyurus. It constitutes the
genus Chcetocercus of Krefft, but is included by Mr. 0. Thomas in
Phascologale, the frequent absence of the fourth lower premolar in
P. thorbeckiana indicating that the total absence of this tooth in the
known specimens of this species cannot be regarded as of generic
importance. All the members of this and the two following genera
can be at once distinguished from Dasyurus by the absence of white
spots on the fur.
Sminthopsis. 2 — The genus Sminthojms includes several small
species allied to Phascologale but characterised by the narrowness
of the hind foot, and by the soles of the feet being either granulated
or hairy, instead of naked.
Antechinomys. 3 — The last genus of the Dasyurince is Antechinomys,
represented only by A. laniger of Queensland and New South Wales.
This elegant little mouse-like creature, which has large oval ears and
1 Temminck, Monographies de Mammalogie, vol. i. p. 56 (1827).
2 Thomas, Ann. Mus. Genov. ser. 2, vol. iv. p. 503 (1887).
3 Krefft, Proe. Zool. Soe. 1866, p. 434.
MO
MARSUPIALIA
a long tail with the terminal part bushy, is distinguished from
Sminthopsis by the absence of the hallux and the great elongation
of the limbs. The tympanic bullae of the skull are also unusually
large, with the mastoid portion much swollen. A full account of
the habits and anatomy of this animal, which appears to be of very
rare occurrence, is given in the Proc. Zool. Soc. 1880, p. 454.
Subfamily Myrmecobiinse. — Molars and premolars exceeding
the normal number of seven on each side. Tongue, long cylindrical,
and extensile.
MyrmecoMus. 1 — Dentition
h c hP f > m t or f '} total 52 or 56,
► '■'.-■"'■ '■.;''''-'' ' 1-
Fig. 41. — Myrmecobius fasciatus. From Gould.
being the largest number of teeth in any existing Marsupial. The
distinction between the molars and premolars is founded not on
a knowledge of the succession of the teeth, but on their form. The
teeth are all small and (except the four posterior inferior molars)
separated from each other by an interval. Head elongated, but
broad behind. Muzzle long and pointed. Ears of moderate size,
ovate, and rather pointed. Fore feet with five toes, all having
strong, pointed, compressed claws, the second, third, and fourth
nearly equal, the fifth somewhat, and the first considerably, shorter.
Hind feet with no trace of hallux externally, but the metatarsal bone
1 Waterhouse, Proc. Zool. Soc: 1836, p. 69.
PERAMELIDjE 141
present. Tail long, clothed with long hairs. Fur rather harsh and
bristly. Female without any pouch, the young when attached to
the nipples being concealed only by the long hair of the abdomen.
Vertebrae : C 7, D 13, L 6, S 3, C 23. A gland on the under
surface of the body just in advance of the sternum.
Of this singular genus but one species is known, M. fasciatus
(Fig. 41), found in western and southern Australia. It is about the
size of an Fnglish squirrel, to which animal its long bushy tail
gives it some resemblance ; but it lives entirely on the ground,
especially in sterile, sandy districts, feeding on ants. Its pre-
vailing colour is chestnut-red, but the hinder part of the back
is elegantly marked with broad, white, transverse bands on a dark
ground.
The special interest of this form lies in its apparent relationship
to those Mesozoic mammals which possess a large number of true
molars (seep. 114); and it is suggested by Thomas that it may
eventually be found advisable to include some of the latter in the
present subfamily.
Family Peramelid.e.
Dentition : i —^- , c - p g, m - • total 46 or 48. Upper incisors
small, with short broad crowns. Lower incisors moderate, nar-
row, proclivous. Canines well developed. Premolars compressed,
pointed. Molars with quadrate tuberculated crowns. Fourth pre-
molar preceded by a small molariform tooth, which remains in place
until the animal is nearly full grown. Fore feet with two or
three of the middle toes of nearly equal size, and provided
with strong, sharp, slightly curved claws ; the other toes rudi-
mentary. Hind feet long and narrow ; the hallux rudimentary
or absent ; the second and third toes very slender, and united in a
common integument ; the fourth very large, with a stout elongated
conical claw ; the fifth smaller than the fourth (see Fig. 43). The
ungual phalanges of the large toes of both feet cleft at their ex-
tremities (as in Maids among the Edentata, but in no other
Marsupials). Head elongated. Muzzle long, narrow, and pointed.
Stomach simple. Caecum of moderate size. Pouch complete,
opening backwards. Alone among Marsupials they have no clavicles.
The PeramelidcB form a very distinct family, in some respects
intermediate between the sarcophagous Dasytiridce and the
phytophagous Macropodidce. In dentition they resemble the former,
but they agree with the latter in the peculiar structure of the hind
feet. In the construction of the fore feet they differ from all other
Marsupials.
The Bandicoots, as these Marsupials are popularly termed, are
14:
MARSUPIAL/A
of fossorial habits, and subsist either on an insectivorous or omni-
vorous diet. It has been generally considered that their syndac-
tylous feet indicate direct affinity with the Diprotodonts, but owing
to the essentially Polyprotodont character of the organisation —
which extends even to their carpal and tarsal bones — Thomas
dissents from this view, and concludes that their syndactylism is an
independently acquired character, and that they are really a direct
offshoot from the Dasyuridce. Some individuals are remarkable for
the presence of a longitudinal groove in the root of the canines, by
which feature they approximate to some of the Mesozoic Polypro-
todont forms. They may be divided into three genera.
Perameles. 1 — Anterior and posterior extremities not differing
greatly in development. Fore feet with the three middle toes well
- — : jg= -
Fig. 42. — Perameles gunni. From Gould.
developed, the third slightly larger than the second, the fourth
somewhat shorter, provided with long, strong, slightly curved,
pointed claws. First and fifth toes very short and without claws.
Hind feet with hallux of one or two phalanges, forming a distinct
tubercle visible externally ; the second and third toes very slender,
of equal length, joined as far as the ungual phalanges, but with
distinct claws ; the fifth intermediate in length between these and
the largely developed fourth toe. Ears of moderate or small size,
ovate, pointed. Tail rather short, clothed with short adpressed
hairs. Fur short and harsh. Vertebrae ; C 7, D 13, L 6, S 1, C 17.
Skull long and narrow, with the bulla single, and its mastoid portion
not inflated.
The animals of this genus are all small, and live entirely on the
ground, making nests composed of dried leaves, grass, and sticks in
1 Geoffrey, Bull. Soc. Philom. vol. iii. p. 249 (1803).
PERAMELIDjE 143
hollow places. They arc rather mixed feeders; but insects, worms,
roots, and bulbs constitute their ordinary diet. The various species
are widely distributed over Australia, Tasmania, New Guinea, and
several of the adjacent islands, as Am, Kei, and New Ireland. The
best known are — P. gunni (Fig. 42), bougamvilki, nasuta, obesida, and
macrura from Australia, and /'. doreyana, raffirayam, and longicaadata
from New Guinea.
Remains apparently referable to existing species are found in
the cave-deposits of New South Wales.
Peragah. 1 — Molar teeth curved, typically with longer crowns
and shorter roots than in the last. Hinder extremities proportionally
longer, and hallux without claw. Muzzle much elongated and
narrow. Fur soft and silky. Ears very large, long, and pointed.
Tail long, its apical half clothed on the dorsal surface with long
hairs which form a crest. Vertebrae : C 7, D 13, L 6, S 2, C 23.
Skull distinguished from that of Perameles by the large size and
double structure of the auditory bulla, of which the mastoid portion
is inflated. There is also an abrupt contraction of the muzzle at
the third premolar.
The type species of Rabbit - Bandicoot (P. lagotis), as these
animals are called, is found in Western Australia, and also occurs
fossil in the cave-deposits of New South Wales. It is the largest
member of the family, being about the size of the common Rabbit,
to which animal it bears sufficient superficial resemblance to have
acquired the name of " Native Rabbit " from the colonists. It
burrows in the ground, but in other respects resembles the true
Bandicoots in its habits.
The smaller P. leucura has short-crowned molars, with distinct
cusps, which are almost obsolete in the type species.
Chceropus.- — Dentition generally resembling that of Perameles,
but the canines are less developed, and in the upper jaw two-rooted.
Limbs very slender ; posterior nearly twice the length of the anterior.
Fore feet with the functional toes reduced to two, the second and
third, of equal length, with closely united metacarpals and short,
sharp, slightly curved, compressed claws. First toe represented by
a minute rudiment of a metacarpal bone ; the fourth by a metacarpal
and two small phalanges without a claw, and not reaching the
middle of the metacarpal of the third ; fifth entirely absent. Hind
foot (Fig. 43) long and narrow, mainly composed of the strongly
developed fourth toe, terminating in a conical pointed nail, with a
strong pad behind it ; the hallux absent or represented by a rudi-
mentary metatarsal ; the remaining toes completely developed, and
with claws, but exceedingly slender ; the united second and third
reaching a little way beyond the metatarso-phalangeal articulation of
1 Gray, in Grey's Australia, vol. ii. p. 401 (1841).
2 Ogilby, Froc. Zool. Soc. 1838, p. 25.
144
MARSUPIALIA
the fourth ; the fifth somewhat shorter. Tail not quite so long as
the body, and covered with short hairs forming a slight crest. Ears
large and pointed, and folded down when the animal
is at rest. Fur soft and loose. Vertebrae : C 7, D
13, L 6, S 1, C 20. Skull short and wide, with a
small and single bulla, and a contraction of the
muzzle at the third premolar.
The only known species of this genus (Fig. 44),
chiefly remarkable for the singular construction of
its limbs, is an animal about the size of a small
Eat, found in the interior of the Australian continent.
Its general habits and food appear to resemble those
of the other Peramelidce. It was first described as
C. ecaudatus by Ogilby from a mutilated specimen,
but the specific name was afterwards changed, as being
inappropriate, by Gray to castanotis.
Suborder Diprotodontia.
For the leading characters of this group, see
page 132.
Family Ehascolomyid^e
Dentition : c f, i $, p ^, m £ = 24. All the teeth
with persistent pulps. The incisors large, scalpriform,
with enamel only on the front surface, as in the
Eodentia. The molars strongly curved, forming from
the base to the summit about a quarter of a circle,
Fig. 43.— Skele-
ton of right hind
foot of Chmropus
castanotis. c, Cal-
caneum ; a, astra-
galus ; cb, cuboid ;
ii, navicular ; c3,
ectocuneiform ; II
and III, the con-
third digits ; IV,
the large and only
functional digit ;
V, the rudiment-
ary fifth digit.
equal, stout,
joined second and ^ e CO ncavity being directed outwards in the upper
and inwards in the lower teeth. The first of the
series, or premolar, appears to have no milk-prede-
cessor, and is single-lobed ; the other four composed
of two lobes, each subtriangular in section. Limbs
and short. Fore feet with five distinct toes, each
furnished with a long, strong, and slightly curved nail, the first and
fifth considerably shorter than the other three. Hind feet with a very
short nailless hallux, the second, third, and fourth toes partially
united by integument, of nearly equal length, the fifth distinct
and rather shorter ; all four provided Avith long and curved nails.
In the skeleton of the foot, the second and third toes are distinctly
more slender than the fourth, showing a slight tendency towards
the peculiar character so marked in the next two families. Tail
rudimentary. Stomach simple, provided with a special gland
situated near the cardiac orifice. Caecum very short, wide, and with
a peculiar vermiform appendage. Eouch present. The auditory
bullae of the skull are imperfect, open behind, with their anterior
PHASC0L0MY11KE
M5
wall formed by a descending process of the squamosal, instead of the
WF^Wimm
Fig. 4-1. — Clmropus castanotts. From Gould.
alisphenoid. Masseteric fossa of mandible with a perforation and
a deep pit.
Fig. 45. — Common Wombat (Phascolornys itrsinus).
Phascolomys. 1 — The existing Wombats (Fig. 45) comprise three
1 GeoiTrov, Ann. du Museum, vol. ii. \>. 365 (1803).
10
146 MARSUPIALIA
species, all of which are included in the one genus Phascolomys,
and all of which date from the Pleistocene.
In the typical group we find the following characters. Fur
rough and coarse. Ears short and rounded. Muffle naked. Post-
orbital process of the frontal bone obsolete. Ribs fifteen pairs.
Vertebras: C 7, D 15, L 4, S 4, C 10-12. The Wombat of Tas-
mania and the islands of Bass's Straits (P. ursinus) and the closely
similar but larger animal of the southern portion of the mainland of
Australia (P. mitchelli) belong to this group.
In the second group the characters are as follows. Fur smooth
and silky. Ears large and more pointed. Muffle hairy. Frontal
region of skull broader than in the other group, with well-
marked postorbital processes. Ribs thirteen. Vertebras : C 7, D
13, L 6, S 4, C 15-16. One species, P. latifrons, the Hairy-nosed
"Wombat of Southern Australia.
In their general form and actions the Wombats resemble small
bears, having a somewhat similar shuffling manner of walking, but
they are still shorter in the legs, and have broader, flatter backs than
bears. They live entirely on the ground, or in burrows or holes
among rocks, never climbing trees, and feed entirely on grass,
roots, and other vegetable substances. They sleep during the day,
and wander forth at night in search of food, and are shy and
gentle in their habits generally, though they can bite strongly when
provoked. The only noise the common Wombat makes is a low
kind of hissing, but the Hairy-nosed Wombat is said to emit a short
quick grunt when annoyed. The prevailing colour of the last-
named species, as well as of P. ursinus of Tasmania, is a brownish
gray. The large wombat of the mainland is very variable in colour,
some individuals being found of a pale yellowish brown, others
dark gray, and some quite black. The length of head and body is
about three feet.
It is noteworthy that P. mitchelli was first described from the
evidence of fossil remains, the living form subsequently described as
P. platyrhinus being found to be indistinguishable. Other extinct
species occur in the Pleistocene of Australia.
Phascolonus. 1 — Remains of a large extinct Wombat, which must
have nearly equalled the dimensions of a Tapir, occur in the
Pleistocene of Queensland, and have been described as Phascolonus.
It is probable that the expanded and flattened upper incisors from
the same deposits iq>on the evidence of which the presumed genus
Scf'jHiriwdon was founded, are likewise referable to the same form.
The characters of both the upper and lower incisors distinguish
Phascolonus from Phascolomys.
1 Owen, Phil Trans. 1872, p. 257.
PHALANGERin.K 147
Family Phalaxgkkid.k.
Dentition extremely vaxiable, owing to the presence of minute
rudimental teeth not constant in the same species, or even in the
two sides of the jaws of the same individnal ; exclusive, however, of
m .■. j- ,.31 ('2—3) (3—4) , . , ..
Tarsipes, the formula 1 r, c ^, p , __.n> w> (B—V t re P resen ' ; s fairly the
general condition of the functional teeth. First incisors long and
stout ; the lower pair very large and pointed, but without the scissoi'-
like action found in the existing Macropodidce ; second and third
lower incisors minute and probably functionless. Fourth premolar
generally secant ; milk-molar generally minute and deciduous at an
early period. Molars either with sharp cutting-crests or bluntly
tuberculate; fourth sometimes absent. Mandible without pit, and
at most a very minute perforation in the masseteric fossa. Limbs
subequal. Fore feet with five distinct, subequal toes, furnished with
claws. Hind feet short and broad, with five well-developed toes ; the
hallux large, nailless and opposable ; the second and third slender,
and united by a common integument as far as the claws. Tail
generally long, and frequently more or less prehensile. Stomach
simple. Caecum present (except in Tarsipes), and usually large.
Pouch complete. Animals of small or moderate size and arboreal
habits, usually feeding on a vegetable or mixed diet, inhabiting
Australia and the Papuan Islands.
The homologies of the lower functionless teeth between the first
incisor and fourth premolar are very difficult to determine, but
it is probable that one represents a canine only when the largest
known number is present ; this tooth, according to Mr. Thomas,
being the first to disappear.
Phalangers are small woolly-coated animals, with long, power-
ful, and often prehensile tails, large claws, and, as in the American
opossums, Avith opposable nailless great toes. Their expression
seems in the day to be dull and sleepy, but by night they
appear to decidedly greater advantage. They live mostly upon
fruit, leaves, and blossoms, although some few feed habitually upon
insects, and all relish, when in confinement, an occasional bird
or other small animal. Several of the Phalangers possess flying
membranes stretched between their fore and hind limbs (Fig. 48),
by the help of which they can make long and sustained leaps
through the air, like the Flying Squirrels, but it is interesting to
notice that the possession of these flying membranes does not seem
to be any indication of special affinity, the characters of the skull
and teeth sharply dividing the flying forms, and uniting them with
other species of the non-flying groups. Their skulls (Fig. 47)
are as a rule broad and flattened, with the posterior part swollen
148
MARSUPIALIA
out laterally, owing to the numerous air-cells situated in the
substance of the squamosal.
The Phalangers are interesting from an historical point of
view, since the Gray Cuscus (Phalanger orientalis) was the first of
the Marsupials of the eastern hemisphere brought to the notice of
Europeans, having been described in a work published at Leyden
in 1611, from an account of a specimen seen at Amboyna during
the third expedition of Admiral Van der Hagen.
The present family corresponds to the Dasyuridce among the
Fig. 46. — Tarsipes rostratus. From GouM.
Polyprotodonts as presenting, on the whole, the most generalised
types of the suborder. The existing forms may be divided into
three subfamilies.
Subfamily Tarsipedinse. — Cheek-teeth almost rudimentary and
variable in number. Tongue long, slender, pointed, and very ex-
tensile. Tail long. Caecum absent.
Tarsipes. 1 — So named from some supposed resemblance of its
foot to that of the Lemurine genus Tarsivs; but it must be remarked
that it has none of the peculiar elongation of the calcaneum and
navicular so characteristic of that genus.
Head with elongated
1 Gervais and Verraux, Proc. Zool. Soc. 1842, p. 1.
PHALAXGERIlhE 149
and slender muzzle. Mouth - opening small. The two lower
incisors are long, very slender, sharp- pointed, and horizontally
placed. All tin' other teeth are simple, conical, minute, and placed
at considerable and irregular intervals apart in the jaws, the number
appearing to vary in different individuals and even on different
sides of the same individual. The formula in a specimen in the
.Museum of the Royal College of Surgeons is i f, c ±, p and m § on
one side, and i on the other; total 20. Kami of the mandible
extremely slender, nearly straight, and without coronoid process or
inflected angle. Fore feet with five well-developed toes, furnished
with small, Hat, scale-like nails, not reaching to the extremity of
the digits. Hind feet rather long and slender compared with those
of the Phalangerince, Inning a well-developed opposable and nailless
hallux ; second and third digits syndactylous, with sharp compressed
curved claws ; the fourth and fifth free, and with small flat nails.
Ears of moderate size and rounded. Tail longer than the body and
head, scantily clothed with short hairs, prehensile. Vertebrae : C 7,
D 13, L 5, S 3, C 24.
Of this singular genus but one species, T. rostratus (Fig. 46), is
known, about the size of a common Mouse. It inhabits Western
Australia, lives in trees and bushes, uses its tail in climbing, and
feeds on honey, which it procures by inserting its long tongue into
the blossoms of Melaleucas, etc. One kept in confinement by Mr.
Gould Avas also observed to eat flies.
Subfamily Phalangerinse. — Teeth normal. One or more
rudimentary teeth between the upper canine and fourth premolar,
and between the first lower incisor and fourth premolar. Tongue
of ordinary structure. No cheek-pouches. Stomach and ascending
colon simple. Caecum long, simple. Tail well -developed, generally
prehensile.
A numerous group of animals, varying from the size of a mouse
to that of a large cat, arboreal in their habits, and abundantly
distributed throughout the Australian region. The members of
this group are the typical representatives of the family, and are
commonly known to the colonists as Opossums.
Phalanger. 1 — The typical genus Phalanger (Cuscus) presents the
following characters. No flying membrane ; size large or medium,
and build stout and clumsy ; fur thick and woolly. Ears short
or medium, hairy externally, and in some cases also internally.
Toes of fore feet subecpial, their relative lengths in the order 4, 3,
5, 2, 1. Claws long, stout, and curved. Soles of feet naked and
striated, with large ill-defined pads. Tail stout and markedly
prehensile, with the proximal half furred like the body, and the
terminal portion entirely naked. Four mamma?. Skull (Fig. 47)
1 Storr, Prodrome Meth. Mamm. \k 33 (1780). Syn. Phalangista, Geoffroy,
Pull. Soc. Philom. vol. i. p. 106 (1796).
HO
MARS UP I A LI A
Fig 47. — Left lateral view of skull of Gray Cuscus (Plw.l-
anger orientalis). After Peters.
stout and strong, with large vacuities in the hinder half of the
palate, and the auditory bullae thick and inflated. Dentition usually
i §, c -i, p fj '»< {■ First upper incisor with nearly circular section,
or only slightly flat-
tened in front ; can-
ine more or less
closely approximated
to third incisor
(which is very small),
and situated partly
in front of the suture
between the pre-
maxilla and maxilla.
Fourth premolar
large, secant, and
placed obliquely to
line of molars.
Molars four-cusped,
with the inner cusps
of the upper ones
crescentoid, and imperfect transverse ridges connecting each pair
of cusps.
The discuses are curious sleepydooking animals, inhabiting the
various islands of the East Indian Archipelago as far west as Celebes,
and being the only Marsupials found west of New Guinea. As
already noted, it was a member of this genus, the Gray Cuscus
(P. orientalis), a native of Amboyna, Timor, and the neighbouring
islands, which was the first Australasian Marsupial known to European
naturalists. There are altogether five species known, all of about
the size of a large cat ; their habits resemble those of other Phalan-
gers, except that they are said to be somewhat more carnivorous.
Trichomrus} — The members of the genus Trichosurus are of
relatively large size, and are distinguished from Phalanger by the
following characters. Ears more or less hairy behind. Relative
lengths of toes of fore feet in the order 4, 3, 2, 5, 1. Hair on the
soles of the hind feet beneath the heel, but not elsewhere. Tail
thick, not tapering, covered with bushy hair up to the extreme tip,
which is naked, but with a naked strip on the inferior surface in
the distal third or half. A gland on the chest. Dentition usually
* ir > c -o> P h m f- Upper incisors of nearly uniform length, the
first much flattened in front. Canine situated some distance behind
the third upper incisor, which it scarcely exceeds in size. Last
premolar and molars very similar to those of Phalanger.
The true Phalangers comprise two species, of which the best
known is the Vulpine Phalanger (T. vulpecula), so common in
1 Lesson, Did. Class. d'Eist. Nat. vol. xiii. p. 333 (1828).
/ "HALANGERW. K 1 5 1
zoological gardens, where, however, it is seldom seen, owing to
its nocturnal habits. It is of about the size and general build of
a small fox, whence its name. In the typical variety the colour
is gray, with a yellowish white belly, white ears, and a black tail.
This variety is a native of the greater part of the continent of
Australia, but is replaced in Tasmania by the closely allied Brown
Phalanger (var. fuliginosa). Its habits are very similar to those of
the Yellow-bellied Flying-Phalanger (Petaurus australis) described
below, except that it is unable to take the flying leaps of that animal.
Like all the other phalaugers, its flesh is freely eaten both by the
natives and the lower class of settlers.
Psetudochirus} — The genus Psmdochirus agrees with the pre-
ceding in the absence of a flying membrane, and presents the
following leading characters. Size large or medium. Fur com-
paratively short and woolly. Ears medium or short, hairy
behind, although seldom closely furred over all this aspect.
Claws medium. Fore toes subequal, the first two distinctly
opposable to the other three. Soles of feet naked, with large,
striated, round pads, and hair beneath the heels. Tail tapering,
markedly prehensile, with its distal third and the whole of the
under surface short-haired ; tip naked underneath for a short
distance. Four marnmse. No gland on chest, Skull with larger
nasals than in the preceding genera; the posterior part of the
palate in most cases fully ossified, and the auditory bulla? generally
somewhat inflated. Dentition (at most) i 2 , c — ^— , p ~, m -.
Upper teeth nearly uniform in length, but the first incisor distinctly
longer than second. Upper premolars variable. Molars with both
inner and outer cusps distinctly crescentoid, and recalling those
of the Selenodont Artiodactyle Ungulates.
Range. — Tasmania, Australia, and New Guinea.
There are about ten species of this genus known, of which the
commonest is Cook's Ring-tailed Phalanger {Psmdochirus peregrinus),
an animal discovered by Captain Cook during his first voyage, at
Endeavour river, North Queensland.
The complex and sub-selenodont character of the molars of this
and the folloAving genus readily distinguish them from the more
typical Phalaugers, and show an approximation to the type of
dentition prevailing in Phascolarctus ; according, however, to Mr.
0. Thomas, a tendency towards the same structure is observable
in unworn molars of young discuses. The genus may be divided
into three groups, of which the first, as typified by the common P.
peregrinus, is restricted to Australia and Tasmania, while the third,
as represented by P. canescens, is only found in New Guinea. P.
albertisi may be taken as the type of the second group, which is
1 Ogilby, Proc. Zovl. Soc. 1836, p. 26.
152 MARSUPIALIA
represented by that species in New Guinea, and by P. archeri in
Queensland. With the exception of P. peregrinus, the species have
a more or less restricted range. Remains of Pseud < whims, probably
referable to existing species, are found in the cave-deposits of New
South Wales.
Petauroides. 1 — With the genus Petauroides, containing only the
single species P. volans, we come to the first of the Flying-Phalangers,
characterised by the possession of a flying membrane along the flanks.
The characters of this genus are as follows. Size large. Fur very
long and silky. Ears large and oval, thickly furred on the back,
but naked internally. Flying-membrane reaching from wrist to
ankle, but very narrow along the sides of the fore-arm and lower
leg. Fore toes subequal, their relative lengths in the order 4, 3, 5,
2, 1. Claws long, curved, and sharp. Tail long, cylindrical, and
bushy, except near its tip, where it is naked and prehensile. Skull
short and broad, with the nasals short, and not extending nearly as
far forwards as the premaxillae. Large vacuities in hinder part of
palate. Auditory bullae inflated and smooth. Dentition usually
* I) c i)i P t> m i> General characters of teeth very similar to those
of Pseudochirus, but the first upper incisor scarcely longer than the
second.
The single species is found in Australia, from Queensland to
Victoria, and is commonly known as the Taguan Flying-Phalanger.
The structure of the skull and teeth indicates close affinity with
Pseudochirus, although the external form is widely different in the
two genera. This Phalanger seems, indeed, to be, so to speak, a
very specialised Pseudochirus, in which the teeth have become
somewhat further diminished and the flying membrane has been
developed.
Dactylopsila." — The genus Dactylopsila is one of the forms with-
out any trace of a flying membrane, its characters being as follows.
Size medium. Body striped black and white. Ears oval, nearly
naked at the ends. Fore toes of very unequal length, the fourth
being enormously elongated ; fourth and fifth toes of pes also
markedly elongated. Claws long, moderately curved. Tail long,
cylindrical, and evenly bushy, with the extremity more or less
naked below. Skull narrow, but with the zygomatic arches greatly
expanded ; palate fully ossified. Dentition : i -if-, c ^, p f , m j .
Upper incisors very large, the third being directed horizontally
forwards; canine small and approximated to the third incisor, which
it resembles. The fourth premolar of moderate size, with its longer
axis placed obliquely. First lower incisor longer than in any other
genus. Molars oblong, with four cusps.
The typical D. trivirgata, or Striped Phalanger, inhabits the
1 Thomas, Cat. Marsupials Brit. Mm. p. 163 (1888).
- Cray, Proc. Zool. Soc. 1858, p. 109.
PHALANGERIDAZ 153
Papuan and North Australian sub-region ; a second species (D.
palpator), characterised by the still greater elongation of the fourth
tinker, occurring in South New Guinea. These animals are said
to he of insectivorous habits, the elongated fourth finger, as in the
analogous instance of the Lemuroid genus Chironiys, being appar-
ently specially adapted for extracting insects and larva' from their
hiding places.
Petaurus. 1 — Size medium or small. Fur very soft and silky.
A broad Hying membrane extending from the outer side of the fifth
digit of the maims to the ankle. Fore toes usually increasing
regularly in length from the first to the fifth, but in some of the
smaller species the fourth is the longest. Claws strong, sharp, and
much curved. Tail long, evenly bushy to the extremity. Glands
on the chest and between the ears. Skull short and wide, with
the nasals expanded posteriorly, and usually two small palatal
vacuities near the second molars. Auditory bullae inflated, and
variable in size. Dentition : i f , c £, p -if, m f . First upper incisors
very large, and taller than canine. Molars with square crowns
rounded at the angles, and four cusps, except in the last, which is
triangular.
This genus, which ranges from New Ireland to South Australia,
but is not found in Tasmania, contains three species, the largest of
which is the Yellow-bellied Flying-Phalanger (P. amtralis), whose
habits are recorded by Mr. Gould as follows. "This animal is
common in all the brushes of New South Wales, particularly those
which stretch along the coast from Port Philip to Moreton Bay.
In these vast forests trees of one kind or another are perpetually
flowering, and thus offer a never-failing supply of the blossoms
upon which it feeds ; the flowers of the various kinds of gums,
some of which are of great magnitude, are the principal favourites.
Like the rest of the genus, it is nocturnal in its habits, dwelling in
holes and in the spouts of the larger branches during the day, and
displaying the greatest activity at night while running over the
small leafy branches, frequently even to their very extremities, in
search of insects and the honey of the newly-opened blossoms. Its
structure being ill adapted for terrestrial habits, it seldom descends
to the ground except for the purpose of passing to a tree too dis-
tant to be reached by flight. "When chased or forced to flight it
ascends to the highest branch and performs the most enormous
leaps, sweeping from tree to tree with -wonderful address ; a slight
elevation gives its body an impetus which, with the expansion of
its membrane, enables it to pass to a considerable distance, always
ascending a little at the extremity of the leap; by this ascent the
animal is prevented from receiving the shock which it would other-
wise sustain."
1 Shaw, Naturalist's Miscellany, vol. ii. pi. lx. (1791).
154
MARSUPIALIA
A second species, P. scmreus, in some ways one of the most
beautiful of all mammals, has been chosen for the accompanying
woodcut.
Gymnobelideus. 1 — Like Petaurus in every respect, but without
any trace of a flying membrane, and with the fifth digit of the
manus slightly shorter than the third. This genus is represented
only by G. leadbeateri of Victoria, and according to Mr. Thomas,
may be regarded as the primitive form from which the specialised
Petaurus has been developed.
Fig. 4S. — Squirrel Flying-Phalanger (Petaurus sciureus).
Dromicia. 2 — Size small, and general appearance dormouse-
like. Ears large and thin, almost naked, and without internal
or basal tufts. No flying membrane. Digits of normal propor-
tions, the relative lengths of those of the manus in the order
3, 4, 2, 5, 1 ; fore claws rudimentary, hind ones long and sharp.
Tail mouse -like, cylindrical, furry at base, the remainder scaly,
with fine hairs, except at the tip, which is naked and prehensile.
1 M'Coy, Ann. Mag. A r . H. (3) xx. p. 2S7 (1S67).
" Gray, in Grey's Australia, appendix, vol. ii. p. 407 (1841).
PHALANGERIDAZ 155
Skull short and broad, with the hinder part of the palate in-
complete, and the auditory bullae large, much inflated, and trans-
parent. Dentition : i 5, c -. p z, n -'. First upper incisor spat-
ulate. and much longer than either of the others. Canine large,
placed at some distance behind the third incisor. Molars (except the
last) with evenly rounded crowns, carrying four small smooth cusps.
This genus, which occurs in New Guinea, Western Australia, and
Tasmania, is represented by four species. It seems to be inter-
mediate between Petaurus and Acrobates, and it has apparently had
to yield place to those more highly organised types in regions where
they have come in contact with one another.
Distccchurus} — Size small. Ears rather short, thinly covered
with hair, but with small tufts at the base. No flying membrane.
Digits of normal proportions, without expanded terminal pads.
Claws curved and sharp. Tail, skull, and dentition as in Acrobates,
with the exception that the fourth premolar is small in the upper,
and absent in the lower jaw.
The one species of Feather-tailed Phalanger (I), pennatus) is
found in New Guinea.
Acrobates.' 2 — Size very small. Ears moderate, thinly covered
with hair, but with small tufts round the base and on the internal
prominences. A narrow flying membrane, fringed with long hairs,
running from the elbow to the flank, and from the latter to the
knee. Four mammae. Digits furnished with expanded and striated
terminal pads, the relative length of those of the manus being in the
order 4, 3, 5, 2, 1. Claws sharp, although somewhat concealed by
the terminal pads. Tail short-haired above and below, with a broad
fringe on either side. Skull short, wide, and depressed. Posterior
portion of palate very imperfectly ossified ; anterior palatal vacuities
almost confined to the maxillae. Auditory bullae low, rounded, and
but slightly prominent. Dentition : i f , c J-, p f, m f . Teeth sharp,
and of an insectivorous type. Upper canine long, and approximated
to third incisor. The three upper premolars large, functional, and
taller than the molars. Molars small and rounded, with smooth
unridged cusps.
There is only one species in this genus, the beautiful little
Pigmy Flying-Phalanger (A. pygmceus), not so big as a Mouse, which
is found in Queensland, New South Wales, and Victoria, and feeds
on the honey it abstracts from flowers, and on insects. Its agility
and powers of leaping are exceedingly great, and it is said by
Mr. Gould to make a most charming little pet.
Subfamily Phaseolaretinae. — Teeth large, normal; no rudi-
mentary premolars before the last upper premolar, or any teeth
1 Peters, Ann. Mus. Gcnov. vol. vi. p. 303 (1874).
2 Desmarest, Nouv. Did. d'Hist. Nat. ser. 2, vol. xxv. p. 405 (1817).
i 5 6
MARSUPIAL! A
between the first lower incisor and fourth premolar. Tongue
of ordinary structure. Distinct cheek -pouches. Stomach with a
special gland near the cardiac orifice. Caecum very long, and (with
the upper portion of the colon) dilated and provided with numerous
longitudinal folds of mucous membrane. In many anatomical
characters, especially the possession of a special gastric gland, this
group resembles the Pkascolomyidce. 1
Phascolarctus. 2 — Dentition: i%, c^,%> \, m±; total 30. Upper
incisors crowded together, cylindroidal, the first much larger than
the others, with a bevelled cutting edge (Fig. 36). Canine very
small ; a considerable interval between it and the premolar, which
is as long from before backwards but not so broad as the true
molars, and has a cutting edge, with a smaller parallel inner ridge.
The molars slightly diminishing in size from the first to the fourth,
with square crowns, each bearing four pyramidal cusps, with curved
ridges radiating from them, and having a structure very similar to
these of Pseudochiriis. The loAver incisors are semiproclivous, com-
pressed and tapering, bevelled at the ends. Premolars and molars
in continuous series, as in the upper jaw. Milk-tooth very minute,
and almost functionless. Fore feet Avith the two inner toes slightly
separated from and opposable to the remaining three, all with strong,
curved, and much compressed
claws. Hind foot (Fig. 49) with
the hallux placed very far back,
large and broad, the second and
third (united) toes considerably
smaller than the other two ; the
fourth the largest. Xo external
tail. Fur dense and woolly.
Ears of moderate size, thickly
clothed with long hairs. Verte-
bras : C 7, D 11, L8, S2, C8.
Ribs eleven pairs, a rare excep-
tion to the usual number (13)
in the Marsupialia.
There is but one species,
the Koala or Native Bear of
the Australian colonists (P. cin-
' r< us), an animal of compar-
atively large size and heavy
build (Fig. 50), found in the
south-eastern parts of the Aus-
tralian continent. It is about two feet in length, and of an ash-
gray colour, an excellent climber, and residing generally in lofty
1 Cf. W. A. Forbes, "Anatomy of the Koala," Proc. Zool. Soc. 1881, p. 180.
- Blainville, Bull. Soe. Philom. 1816, p. 116.
f Fig. 4 1 .'.— Skeleton of right hind foot of Koala
(I'hascolarctus cinereus), showing the stout op-
posable hallux, followed by two slender toes,
which in the living animal are enclosed as far
as the nails in a common integument.
l^HALAXGERin.E
157
Eucalyptus trees, on the buds and tender shoots of which it feeds,
though occasionally descending to the ground in the night.
Extinct Phalangeroids.
Numerous imperfect remains recently described by De Vis are
regarded as indicating large extinct types of Phalangeridce, but
further evidence is required before all these determinations can he
definitely accepted. Thus part of an upper jaw is provisionally
referred to a large species of Pseudochirus, while part of a scapula
is made the type of a genus Archizonums which appears to be
Fig. 50. — The Koala (Phascolarctus cinereus). From Sclater, Proc. Zool. Soc. 18S0, p. 355.
allied to the former. Another fragmentary scapula is considered to
indicate a large Phalanger. Finally, part of a fibula described under
the name of Koalemus is regarded as affording evidence of the
former existence of a large ancestral form allied to the Koala, and
it is suggested that an upper jaw with teeth may belong to the
same or an allied type.
Thylacoleo. 1 — Dentition of adult: i -J, c ^, p -|, I m\ m > total 28.
First upper incisor much larger than the others ; canine and first
two premolars rudimentary. In the lower jaw the two small
anterior premolars are functionless, and often deciduous ; posterior
premolars of both jaws formed on the same type as those of Potorous,
but relatively much larger ; true molars rudimentary, tubercular.
One species, T. carnifex. This animal presents a most anomalous
1 Owen, in Gervais's Zool. et Pal. frangaises, 1st ed. pt. i. p. 192 (1849-52).
i 5 8
MARS UP I A LI A
condition of dentition, the functional teeth being reduced to one
pair of large cutting incisors situated close to the median line, and
one great, trenchant, compressed premolar, on each side above and
below. It was first
described as a car-
nivorous Marsupial,
and named, in ac-
cordance with its
presumed habits,
" as one of the fel-
lest and most de-
structive of preda-
tory beasts " ; but,
as its affinities are
certainly with the
Phalangerida' and
Macropodidce, and
its dentition com-
pletely unlike that
of any known pre-
daceous animal, this
view has been called
in question.
The dentition is
nearer to that of the
existing Phalangerida than to that of the Macropodidce, and the
genus may be provisionally regarded as the type of a distinct
subfamily of the former.
Pig. 51. — Front view of skull of Thylacoleo carnifex, restored.
J natural size. From Quart. Journ. Gcol. Soc. vol. xxiv. p. 312.
Family Macropodid.e.
Dentition i
(0-1)
1'
P
2' m i
Incisors sharp and cutting,
&>
those of the lower jaw frequently having a scissor -like action
against one another ; upper canine, if present, small. Penultimate
premolar shed with the fourth milk-molar, which is molariform and
long persistent. Molars wide, and either transversely ridged or
bluntly tuberculate. Premolars and molars moving forwards in the
skull as the age of the animal increases, this being most marked in
the larger species. Masseteric fossa of mandible hollowed out
below into a deep cavity walled in externally by a plate of bone,
and communicating with the inferior dental canal by a large
foramen. Hind limbs usually larger than the anterior ones, and
progression generally saltatorial. Fore feet with five digits ; hind
feet syndactylous, the fourth digit being very large and strongly
clawed ; hallux usually absent. Tail generally long and hairy,
MACROPODIDjE
•59
large
and
by peculiarities
teeth, and other
that of a sheep
head, especially
occasionally prehensile; stomach sacculated. Pouch
opening forwards.
The Macrqpodidce or Kangaroos, taken as a whole, form a very
well-marked family, easily distinguished from the other members of
the suborder by their general conformation, and
in the structure of their limbs,
organs. They vary in size from
down to a small rabbit. The
in the larger species, is small,
compared with the rest of the body, and tapers
forward to the muzzle. The shoulders and fore
limbs are feebly developed, and the. hind limbs
usually of dispi'oportionate strength and magnitude,
which gives them a peculiarly awkward appearance
when moving about on all fours, as they occasion-
ally do when feeding. Rapid progression is, how-
ever, performed only by the powerful hind limits,
the animal covering the ground by a series of
immense bounds, during which the fore part of the
body is inclined forwards, and balanced by the
long, strong, and tapering tail, which is carried
horizontally backwards. When not moving they
often assume a perfectly upright position, the tail
aiding the two hind legs to form a sort of support-
ing tripod, and the front limbs dangling by the
side of the chest. This position gives full scope
for the senses of sight, hearing, and smell to warn
of the approach of enemies, from which these
animals save themselves by their bounding flight.
The fore paws have five distinct digits, each armed
with a strong curved claw.
Fig. 52. — Skeleton
of right hind foot of
Kangaroo.
The hind foot (Fig. 52), as being a typical
example of the syndactylous modification, may be
noticed in some detail. It is extremely long and
narrow, and (with only one exception) without any
hallux or great toe. It consists mainly of one very large and strong
toe, corresponding to the fourth of the human or other typically
developed foot, ending in a strong, curved, and pointed claw.
Close to the outer side of this lies a smaller fifth digit, and to the
inner side two excessively slender toes (the second and third),
bound together almost to the extremity in a common integument.
The two little claws of these toes, projecting together from the
skin, may be of use in scratching and cleaning the fur of the
animal, but the toes themselves must have cpiite lost all connexion
with the functions of support or progression.
The dentition of the Kangaroos, functionally considered,
i6o
MARSUPIAL! A
consists of sharp -edged incisors, most fully developed near the
median line of the mouth, for the purpose of cropping the various
kinds of herbage on which they feed, and ridged and tuberculated
molars for crushing it, there being no tusks or canines for offensive
or defensive purposes.
The number of vertebras is — in the cervical region 7, dorsal 13,
lumbar 6, sacral 2, caudal varying according to the length of the
tail, but generally from 21 to 25. In the fore limb the clavicle
and the radius and ulna are well developed, allowing of considerable
freedom of motion of the hand. The pelvis has large epipubic or
" marsupial " bones. The femur is short, and the tibia and fibula
Fig. 53.— The Great Gray Kangaroo (Macropus giganteus).
are of great length, as is the foot, the whole of which is applied to
the ground Avhen the animal is at rest in the upright position.
The stomach is of large size, and very complex, its walls being
puckered up by longitudinal muscular bands into a great number of
sacculi, like those of the human colon. The alimentary canal is
long, and the caecum well developed. All the species have a
marsupium or pouch formed by a fold of the skin of the abdomen,
covering the mammary glands with their four nipples. In this
pouch the young are placed as soon as they are born ; there their
growth and development proceeds ; and to it they resort tempor-
arily for the purpose of shelter, concealment, or transport, for some
time after they are able to run and jump about the ground and
feed upon the same herbage which forms the nourishment of the
parent. During the early period of their sojourn in the pouch,
MACROPOniD.K 161
i lie blind, naked, helpless young creatures (which in the Gic.it
Kangaroo (Fig. 53) scarcely exceed an inch in length) are attached
by their mouths to the nipples of the mother, and are fed by
milk injected into their stomach by the contraction of the muscle
covering the mammary gland.
The Kangaroos are all vegetable feeders, browsing on grass and
various kinds of herbage, the smaller species also eating roots.
They are naturally timid, inoffensive creatures; but the larger ones
when hard pressed will turn and defend themselves, sometimes
killing a dog by grasping it in their fore paws, and inflicting
terrible wounds with the sharp claws of their powerful hind legs,
sustaining themselves meanwhile upon the tail. A few aberrant
forms are arboreal. The great majority are inhabitants of Australia
and Tasmania, forming one of the most prominent and characteristic
features of the fauna of these lands, and in the scenery of the
country, as well as the economy of nature, performing the part of
the deer and antelopes of other parts of the world, which are
entirely wanting in Australia. Kangaroos were very important
sources of food-supply to the natives, and are hunted by the colon-
ists, both for sport and with a view to their destruction, on account
of the damage they naturally do in consuming the grass, now
required for feeding cattle and sheep. Notwithstanding this, they
have in some districts increased in numbers, owing to the sup-
pression of their former enemies, the aborigines and the Dingo or
native dog. A few species are found in New Guinea and the
adjacent islands, Avhich belong, in the zoological sense, to the
Australian region.
Before noticing the various generic types of the Macropodidce, a
few words are necessary in respect of the tooth-change, and we may
here quote the observations of Mr. 0. Thomas on this subject.
" The full dentition of the members of this family consists, in the
upper jaw, first of three incisors, then of a small canine (often,
however, suppressed, as in Fig. 55), and then of six cheek-teeth,
of which the second in the series is the only one which has a milk
or deciduous predecessor, and is therefore the one to be regarded
as the last premolar of the typical mammalian dentition. The
special characteristics that render the development and succession of
the teeth in the Macropodidce, and especially in the genus Macropux,
so puzzling to systematic zoologists, are : firstly, a general pro-
gression forwards in the jaw of the whole tooth-row, comparable to
that found elsewhere only in the Elephants and some Sirenians ;
and, secondly, the fact that before the tooth-change the first tooth
of the series (p 3) and the single milk-tooth (dm 4) placed next to
it, both of which fall out at the change, are respectively so very
similar in shape and size to the first and second teeth of the
permanent series, viz. the permanent premolar (p 4) and the first
11
1 62 MARSUPIALIA
molar (m 1), as to be most naturally mistaken for, or compared with,
them in specific descriptions. . . . The necessary knowledge as to
the stage of dentition in which any skull may be, can often be
gained only by cutting open the bone either above and behind the
first tooth of the series to see if the true permanent p 4 be still
buried there (in which case, of course, that first tooth is only p 3),
or behind the last visible molar to see if there be yet another tooth
behind it, showing it to be m 3 and not m 4. The first plan is,
as a rule, the better, since p 4 is generally by far the most
important tooth for diagnostic purposes, and its characters have,
therefore, in any case to be taken into account."
The Macropodidce are divided into three well-marked sections :
(1) the true Kangaroos (Macropodince) ; (2) a group consisting of
smaller animals, commonly called Rat Kangaroos, or (improperly)
" Kangaroo Rats," or sometimes Potoroos ; and (3) the Hypsipryrrir
nodontince, now represented only by a single species.
Subfamily Hypsiprymnodontinse. — Size very small. Claws
small, feeble, and subequal. Hind feet with an opposable hallux.
Tail naked and scaly. The fourth premolar twisted obliquely out-
wards, as in Phalanger. Other teeth as in the Potoroince.
This subfamily is now represented only by the genus Hypsi-
prymnodon, 1 which is a form of great interest, as showing a structure
of foot connecting that of the Kangaroos Avith that of the Phalan-
gers. The single known species, H. moschatus, was described by
Ramsay from specimens discovered in north-east Australia. It
was described almost simultaneously by Owen under the name of
Pleopus nudicaudatus. From the resemblance in the structure of the
foot and the obliquity of the premolars to the Phalangers Mr.
Thomas has some hesitation as to which family should receive this
genus, but the macropine characters of the mandible preponderate
in favour of the Maoropodiace.
Triclis.' 2 — A lower jaw of a much larger form from the Pleisto-
cene deposits of Australia apparently indicates another member of
this subfamily, having the outwardly directed and grooved pre-
molar characteristic of Hypsiprymnodon. It differs, however, from
that genus, and also from all other known Macropodidce, in having
a small tooth between the incisor and fourth premolar, which
apparently represents a canine, or perhaps an anterior premolar.
This form indicates, therefore, a closer connexion between the
Phalangeridce and Macropodidce than any other.
Subfamily Potopoinse. — The second section or subfamily, the
Potoroinm, have the first upper incisor narrow, curved, and much
exceeding the others in length (Fig. 54). Upper canines always
persistent, flattened, blunt, and slightly curved. Premolars of both
1 Ramsay, Proc. Linn. Soc. K. S. Wales, vol. i. p. 33 (1876).
2 De Vis, Proc. Roy. Soc. Queensland, ser. 2, vol. iii. p. 8 (1888).
MACROPODin.E 163
jaws always having large, simple, compressed crowns, with a nearly
straight or slightly concave free cutting edge, both outer and inner
surfaces usually marked by a series of parallel, vertical grooves and
ridges, these teeth heinir either set in the same line with the
molars, or slightly bent outwards. Molars with quadrate crowns,
having a blunt, conical cusp at each corner, the fourth notably
smaller than the third, sometimes rudimentary, and appearing early.
Fore feet narrow ; three middle toes considerably exceeding the
first and fifth in length ; their claws long, compressed, and but
slightly curved. Hind feet as in Macropus. Tail long and hairy,
sometimes partially prehensile, being used for carrying bundles of
grass with which these animals build their nests.
The Potoroos or Rat Kangaroos are all small animals, none of
them exceeding a common rabbit in size. They inhabit Australia
and Tasmania, are nocturnal, and feed on the leaves of various
m m 1:1 m
Fig. 54.— Skull and Teeth of Rat Kangaroo (Bettongia lesueuiri). c, Upper canine.
The other letters as in Fig. 51.
kinds of grasses and other plants, as well as roots and bulbs, which
they dig up with their fore paws. Nine species are known, present-
ing a considerable range of diversity in minor characters, and
admitting of being grouped in four principal sections, which may
be allowed the rank of genera. These are :
Potorous. 1 — Head long and slender. Auditory bullae some-
what inflated. Eidges on premolars few and perpendicular.
Large palatine foramina. Tarsus short. Muffle naked. Three
species, viz. P. tridaetylus, P. gilberti, and P. platyops ; the last two
being confined to West Australia.
Bettongia. 7, — Head comparatively short and broad. Ears short
and rounded. Auditory bullae generally much inflated. Large
palatine foramina. Tarsus long. Eidges on premolars numerous
1 Desmarest, Nbuv. Diet. d'Hist. Nat. ser. 1, vol. xxiv. Table Meth. p. 20
(1804). Syn. Hypsiprymnus, Illiger, Prodromus Syst. Mamm. p. 79 (1811).
- Gray, Charlesworth's Mag. Nat. Hist. vol. i. i>. 584 (1837).
1 64
MARSUP1ALIA
and oblique. Tail more or less prehensile, thickly haired, and
the hairs on the upper surface longer than those on the lower, and
forming a crest. Muffle naked. Four species, viz. B. pcnicillato,
B. cunicidus, B. gaimardi, B. lesiieuiri.
Caloprymnus. 1 — Muffle naked, as in Bettongia, but the edge of the
hairy part less emarginate backwards in the middle line. Ears
short, rounded, and hairy. Auditory bullae much inflated, and of
large size. Nasals larger and wider behind than in the other
genera. Very long anterior palatine foramina. Limbs as in
Bettongia. Tail thin, cylindrical, evenly coated with short hair,
without trace of a crest. Skull broad and flat, with a remarkably
short and conical muzzle. The sole representative of this genus is
C. campestris of South Australia, originally referred to Bettongia.
jj m i
Fig. 55. — Skull and Teeth of the Red-necked Wallaby (Macropus ruficoUis). i 1 , i-, i 3 , First,
second, and third upper incisors ; pm, fourth or posterior premolar (the penultimate or third
having been already shed); ml, m 2 , 7)13, m t t the four true molars. The last, not fully de-
veloped, is nearly concealed by the ascending ramus of the jaw.
JEpyprymnus.- — Head short and broad. Auditory bullae not
inflated. No palatine foramina. Tarsus long. Muffle partially
hairy. Tail evenly hairy, not crested above. Molars oblong, less
distinctly quadritubercular, and not decreasing so much in size pos-
teriorly as in the other genera. Represented only by JE. rufescens.
Remains of JE. rufescens occur in the Pleistocene cave-deposits
of New South Wales.
Subfamily Maeropodinae. — This subfamily includes the largest
forms. The cutting edges of the upper incisors are nearly level, or
the first pair but slightly longer than the others (Fig. 55). The
canines are rudimentary and often wanting. The premolars are
usually not longer (from before backwards) than the true molars
1 Thomas, Cat. Marsup. Brit. Mas. p. 114 (1888).
" Garrod, Proc. Zool. Soc. 1875, i». 59.
MACROPODID.i: 165
and less compressed than in the last subfamily; they are placed
in precisely the same line with the molars. The crowns of the
molars always have two prominent transverse ridges; and these
teeth increase in size from before backwards, the fourth molar
appearing very late. The fore limbs are small, with sul)equal toes
armed with strong, moderately long, curved claws. Hind limbs
very long and strongly made. Head small, with more or less
elongated muzzle. Ears generally rather long and ovate.
Upwards of forty-four existing species of this group have been
described, and many attempts have been made to subdivide them into
smaller groups or genera for the convenience of arrangement and
description, but these have generally been based upon such trivial
characters that it is preferable to speak of many of them as sections
of the genus Macropus, reserving generic rank only to forms some-
what aberrant in structure. According to this arrangement the
genera Anil be as follows :
Lagostrophus. 1 — Eepresented only by the Banded Wallaby
(L. faseiatus) of Western Australia, which presents the following
distinctive features. Size small. Muffle naked. Hind feet covered
with long bristly hairs, concealing the claws. Lower part of back
marked by dark cross-bands. Skull with a narrow pointed muzzle
and inflated auditory bullae ; symphysis of mandible firmly united.
No canine. Upper incisive series meeting at a sharp angle, and
diverging but slightly behind. First incisor smaller in section than
either of the others and scarcely longer, bluntly pointed ; second
with a flattened oral surface ; third smaller, similarly flattened, but
with a groove on oral surface forming a notch at its postero-
external angle. Fourth premolar short, with a distinct inner ledge.
Molars as in Macropus.
Dendrolagus. 2 — General proportions of limbs and body normal
and unlike those of other members of the family. Muffle broad and
only partly naked. Fur on nape, and sometimes on back, directed
forwards. Fore limbs nearly as large as the hind ; hind feet with
the syndactylous second and third digits relatively large ; claws of
fourth and fifth hind digits curved like those of the manus. Tail
very long, and thickly furred. Skull stout, with a short and wide
muzzle ; the posterior part of the palate fully ossified, and the
auditory bullae not inflated. A small canine. Fourth premolar
large, but much shorter antero-posteriorly than in the next genus ;
molars as in the latter.
This genus includes four species of Tree-Kangaroos, three of
which occur in New Guinea, while D. lumholtzi is found in North
Queensland. They differ greatly from all the other forms in being
chiefly arboreal in their habits, climbing with facility among the
1 Thomas, Proc. Zool. Soc. 1886, p. 544.
2 Schlegel and Miiller, Verh. Nat. Ges. Nederland, p. 138 (1839-44).
1 66 MARSUPIALIA
branches of large trees, and feeding on the bark, leaves, and fruit.
They are confined to the tropical forests of the regions mentioned ;
and it would appear that we must regard their resemblance in the
proportions of the limbs and habits to the Phalangers as having
been independently acquired.
Dorcopsiz. 1 — Hind limbs relatively less large than in Macropu*.
Muffle large, broad, and naked. Ears small. Fur on nape directed
wholly or partially forwards. Hind claws not concealed by hair.
Tail with a nearly naked tip. Skull long and narrow, with the
auditory bullae not inflated. A well-developed canine. First upper
incisor somewhat short ; second and third nearly equal, notched
externally. Fourth premolar greatly elongated antero-posteriorly,
its length generally exceeding the united lengths of the first and
second molars ; a distinct inner ledge, and vertical grooves on both
sides. Molars low and rounded, with the median longitudinal
bridge between the ridges almost or quite aborted, and the talon in
front of the first transverse ridge very narrow, and not extending
to the inner side. The two series of cheek-teeth parallel, or nearly
so, instead of converging at the extremities.
Three species of this genus are known, all of Avhich are from
New Guinea ; the type being D. muclleri. In the characters of the
dentition, the forward inclination of the fur on the nape, and other
points, this genus is allied to Dendrolagus ; but Dorcopsis macleayi
connects the other species with Mavropus.
Lagorchestes.' 2 — Muffle entirely or partially covered with hair.
Fourth hind digit with a long claw, not concealed by hair. Tail
rather short, evenly furred, without a spur. Skull with short
muzzle and diastema, and inflated auditory bulla. Canine present,
sometimes very small. Fourth premolar large, not constricted in
the middle, with a continuous inner ledge.
This genus includes the Hare - Kangaroos, a group of small
hare-like animals, great leapers and swift runners, which mostly
affect the open grassy ridges, particularly those of a stony character,
sleeping in forms or seats like the common hare. Their limbs are
comparatively small, their claws sharp and slender, and their muffle
is clothed with velvet-like hairs. Three species — M. leporoides, M.
/nrsutiis, M. conspicillatux.
The range extends over the whole of Australia, but does not
embrace Tasmania.
Onychogale. 3 — Muffle hairy. Fourth hind claw long, narrow,
compressed, and sharp. Tail long and tapering, covered with short
hair, and furnished at the tip with a horny spur. Skull nearly as in
Macropus, with the auditory bullae more or less inflated. Canine
1 Schlegel and MLiller, Vcrh. Nat. Gcs. Ncderland, p. 130 (1839-44).
- Gould, Monograph of Macropodid(c,\>\. xiii. (1S41).
3 Gray, in Greys Australia, vol. ii. appendix, p. 402 (1841).
MACROPODW.E 167
small or wanting. Upper incisors small, decreasing in size from first
to third. Fourth premolar small, hour-glass shaped, and without,
inner ledge. Molars as in Macropus.
This genus contains three species, having the same distribution
as Lagorehesft s. Mr. 0. Thomas observes : " The spur-tailed Wallabies
form a natural little group, distinguished both by the shape of the
incisors and the peculiar horny excrescence at the tip of the tail.
The latter character is altogether unique among Marsupials, and is
only found among other mammals in the Lion, which occasionally
has a somewhat similar horny spur at the end of its tail. In the
case of the Wallabies it is difficult to conceive what can be the
use of this spur ; and observations on the living animal are much
needed with regard to this interesting point."
Petrogale? — Muffle naked. Fur of nape directed backwards.
Claw of fourth hind digit very short. Tail long, cylindrical, thinner
than in Macropus, and thickly haired and pencilled at the extremity.
Sktdl as in the smaller sj)ecies of Macropus, with large posterior
palatal vacuities, and the bulla? sometimes inflated. No canine.
Upper incisors small, the third resembling that of Macropus. Fourth
premolar large and stout, as in some of the Wallabies, with a con-
tinuous inner ledge, and two or three indistinct vertical ridges
externally. Molars as in the Wallabies.
This genus is represented by six species, of which P. penicillata
is a well-known example, ranging over the whole of the mainland of
Australia. The Rock- Wallabies, as its members may be called, are
very closely allied to some of the true Wallabies ; and some hesitation
may be expressed as to the advisability of accepting their generic
separation from Macropus. They inhabit rocky regions, making
their retreats in caverns and crevices, leaping with surprising agility
from one narrow ledge to another, and browsing upon the scanty
herbage that the neighbourhood of such situations affords. The
species are P. mnthopus, P. penicillata, P. lateralis, P. concinna, P.
brachyotis, P. inornata.
Remains of P. penicillata are found in a fossil state in the
Pleistocene cave-deposits of New South Wales.
Macropus. 2 — Muffle generally completely naked. Ears large.
Fur on nape (with an occasional exception in two species) directed
backwards. Claw of fourth hind digit very long. Tail thick,
tapering, and evenly furred. Four mamma?. Skull (Fig. 55) long,
smooth, and rounded ; the nasals expanded behind ; generally large
palatal vacuities ; and the auditory bullae not inflated. Canine
minute, and shed at an early period. Incisor series forming an
open curve ; the first the tallest, and the third nearly always the
longest antero-posteriorly, and generally with an infolding of enamel
1 Gray, Oharlesworth's Mag. Nat. Hist. vol. i. p. 583 (1837).
2 Shaw, Naturalist's Miscellany, vol. i. pi. xxxiii. (1790).
1 68 MARSUPIALIA
e>
near its posteroexternal angle. Fourth upper premolar with a
secant edge, and an inner basal ledge or tubercle ; correspondin
lower tooth secant ; both may be longer or shorter than first molar
Molars (except very occasionally) with a distinct longitudinal bridge
connecting transverse ridges. Lower incisors long and scalpriform,
with inner secant edges opposable, owing to the loose articulation of
the mandibular symphysis.
This genus includes the true Kangaroos and Wallabies, the size
of the individual existing species varying from that of a Rabbit
to that of a Man. There are no less than twenty-three existing
species, which may be divided into three groups, as well as many
extinct ones. The genus is found in Australia and New Guinea,
as well as in the eastern half of the Austro-Malayan transitional
region.
The first group, or true Kangaroos, comprises the largest
existing forms, which are generally of a uniform and sombre colour.
The skull is of a large and massive type, with the palate more
or less well ossified posteriorly, while the molars frecpiently have
a median longitudinal bridge connecting the first transverse ridge
with the anterior talon, and no antero-external bridge between the
same ridge and talon. The history of the discovery of the typical
representative of this group, as being of considerable interest, may
be given at some length. When Captain Cook, during his first
memorable voyage of discovery, was detained for the purpose of
refitting his ship at Endeavour river on the north-east coast of
Australia, a strange-looking animal, entirely unknown to them, was
frecpiently seen by the ship's company; and it is recorded in the
annals of the voyage that, on the 14th of July 1770, "Mr. Gore,
who went out this day with his gun, had the good fortune to kill
one of the animals which had been so much the subject of our
speculation, . . . and which is called by the natives kanguroo," a
name which, though it does not appear to be now known to any of
the aboriginal tribes of the country, has been adopted for this
animal in all European languages, with only slight modifications of
spelling. With the exception of a passing glimpse in the beginning
of the same century by the Dutch traveller Bruyn of some living
examples of an allied species, this was the first introduction to the
civilised world of any member of a group of animals now so
familiar. The affinities of the species, skins of which were brought
home by Captain Cook and subsequent voyagers, were recognised
by Schreber as nearer to the American opossums (then the only
known Marsupials) than to any other mammals Avith which zoologists
were acquainted, and consequently it Avas placed by him, in his
great work on the Mammalia, then in the course of publication, in the
genus Didel/phys, with gigantea for a specific designation, — the latter
having been bestowed upon it by Zimmermann under the impression
MACROPODID.K 169
that it was a huge species of jerboa. Soon afterwards (1791) Dr.
Shaw very properly formed a new genus for its reception, which
he named Macropus, in allusion to the peculiar length of its hind
foot. By the name thus formed, Macropus giganteus, this kind of
Kangaroo has ever since been known in zoological literature. It is
the common Gray Kangaroo, called " boomer," " forrester," or " old
man" by the colonists, and frequents the open grassy plains of the
greater part of eastern Australia and Tasmania; a figure being
given in the woodcut on p. 1G0. The muffle is partly covered
with hair, and the fourth premolar very short. Several varieties
are known.
A sub-group, distinguished from the above by the naked
muffle, includes some very large and handsome species, which prin-
cipally dwell in rocky mountain ranges, as 31. rufus, the great Red
Kangaroo, M. antilopinus, and 31. robustus. The fourth premolar is
of large or medium size in these forms. Remains of 31. giganteus
occur fossil in the Pleistocene of Australia, where we also find the
allied extinct M. titan, which attains somewhat larger dimensions.
M. robustus also dates from the same geological epoch, where it was
accompanied by two allied types known as M. alius and 31. cooperi.
The second group includes the larger Wallabies, which are
smaller than the true Kangaroos, with a brighter and more
variegated coloration. The palate is generally more incomplete
than in the typical group ; and in the molars the anterior talon is
connected with the first transverse ridge by an external instead of
a median longitudinal bridge. The members of this group are
frequenters of forests and dense impenetrable brushes and scrubs,
and hence are often called Brush Kangaroos, though a native name,
" Wallaby," is now generally apjilied to them. There are several
species, of which 31. rvficollis, 31. ualabatus, M. parryi, and 31. agilis
are the best known.
.1/. ualabatus and 31. parryi are found fossil in the Pleistocene
deposits of Australia. In those beds we also meet with remains of
several very large extinct species, which appear to be allied to those
Wallabies in which the fourth premolar is large and elongated, all
of them agreeing with the Wallabies in the absence of the median
bridge between the first ridge and talon of the molars. These fossil
forms comprise 31. brehus, in which the skull Avas probably about
one foot in length, and 31. roxhus, and 31. anak, which were of some-
what inferior dimensions. In the last-named species the length of
the fourth upper premolar is equal to that of the first and half of
the second molar. 1
The third and last group of the genus includes the small
1 For the characters of these species and the undermentioned distinct genera,
see Owen's Extinct Mammals of Australia (1877), and Lydekker's Catalogue of
Fossil Mammalia in the British Musacn, pt. v. (1887).
i7o MARSUPIALIA
Wallabies, which are small and lightly-built animals, in some
instances not larger than a Rabbit. Their muffles are always naked,
and in the skull the anterior palatine foramina are small and the
posterior vacuities very large, while the posterior expansion of the
nasals is very marked. The third upper incisor is smaller than in
the last group. This group extends farther into the tropics than
either of the others, being found in the New Britain and Aru
islands, as well as in New Guinea. M. brachyurus is remarkable for
its comparatively short and slender tail and small ears. The earliest
known species of Kangaroo, referred to before, M. bruni, belongs to
this section. Several examples Avere seen by Bruyn in 1711 living
in captivity in the garden of the Dutch governor of Batavia, and
described and figured in the account of his travels (Eeizen over
Moskovie, etc.) under the name of "Filander." It was quite lost
sight of, and its name even transferred by S. Muller to another
species (Dorcopsis muelleri), until rediscovered in 1865 by Rosenberg,
who sent a series of specimens to the Leyden Museum from the
islands of Aru and Great Key, thus determining its true habitat.
M. thetidis is a well-known Australian representative of this
group.
Extinct genera. — In addition to the fossil forms already mentioned
which can be referred to existing genera, there are others from the
Australian Pleistocene indicating extinct generic types of Macropod-
idcB, to which brief reference may now be made. The first of these
is Sthmurus, 1 represented by a single large species (S. atlas), and
characterised by the presence of a complete inner lobe to the fourth
upper premolar, and of an outer one in the opposing lower tooth,
so that these teeth present a flat and oval grinding surface when
worn. The median longitudinal bridge connecting the transverse
ridges of the molars is very imperfect ; and in the upper molars
there is no bridge between the first ridge and talon. In Procoptodon 2
the premolars resemble those of Sth&rwrus, but the molars are
elongated, and usually have their enamel thrown into numerous
vertical foldings. The most distinctive feature is, however, the
complete ankylosis of the mandibular symphysis ; the mandibular
rami being deep, and the diastema in the dental series short. The
lower incisors are nearly cylindrical, and the palate has large
vacuities. Three species are known. The largest representation of
the whole family is the type of the genus Pabrchestes 3 (P. azael), in
which the length of the skull is estimated at sixteen inches. It is
distinguished from Procoptodon by the longer mandibular symphysis
and diastema, and the spatulate lower incisors. The true molars
have no distinct anterior talon, and are not grooved, while the
palate was fully ossified.
1 Owen, Phil. Trans. 1874, p. 264.
2 Owen, op. cit. p. 788. 3 Owen, op. cit. p. 797.
EX TIXC T FA Mil IKS
171
Extinct Families.
Hero may be noticed two genera of extinct Marsupials, the remains
of which have been found in the Pleistocene deposits of Australia,
which agree with the MacropodidcB and the Phalange/idee in having
I incisors, those of the lower jaw being very large and proclivous.
As the whole of their structure, especially that of the hind feet, is
not yet known, their precise affinities cannot he determined.
DiprotodonJ 1 — Dentition : i f, c #, p \, m •£- ; total 28. The first
upper incisor very large and sealpriform (Fig. 56). True molars
with prominent transverse ridges, as in Macropus, but -wanting
the longitudinal connecting bridge. Anterior and posterior limbs
less disproportionate than in the Kangaroos. Humerus elongated,
and differing from that of nearly all Marsupials in the absence of an
Fig. 56. — Left lateral aspect of the skull of Diprotodon australis; from the Pleistocene of
Australia. 7 V, natural size, i, Incisors ; p, premolar ; m, molars. (After Owen.)
entepicondylar foramen. The palate is fully ossified, and there is
no pit or perforation in the masseteric fossa of the mandible. I),
australis is the largest known Marsupial, being fully equal in bulk
to a Rhinoceros. It may be regarded as the type of a family —
Diprotodontidce — having affinity on the one hand with the Phalangers
and on the other with the Kangaroos.
XutofJir r'ui in.' 1 — Represented by a species of somewhat smaller
size than the type of Diprotodon, with a shorter skull, in which the
zygomatic arches are very wide and the nasals curiously expanded
at their extremities. The mandibular symphysis is ankylosed ;
1 Owen, in MitchelVs Eastern Australia, 2d ed. vol. ii. p. 362 (1838).
2 Owen, Cat. Mamm. a ml Arcs, Mas. /,'. Coll. Surgeons, p. 314 (1845).
172 MARSUPIALIA
and, as in Diprotodon, there appears to have been no tooth-change.
The humerus probably referable to Nototheriwm is of a short and
widely expanded type, with a large entepicondylar foramen, and
coming nearer to that of the Wombat than to that of any other
existing form. The Notothcriidre may apparently be regarded as a
distinct family connecting the Diprotodontidce with the Phasco-
lomyidce and Phalangeridce.
Bibliography of Marsupialia. — G. R. "Waterhou.se, Ned. Hist, of the Mammalia,
vol. i. " Marsupiata," 1846 ; J. Gould, Mammals of Australia, 1863 ; R. Owen,
article "Marsupialia," in Cyclop, of Anatomy and Physiology, and various
memoirs "On Extinct Mammals of Australia" in Philosophical Transactions;
W. H. Flower, "On the Development and Succession of the Teeth in the Mar-
supialia," Phil. Trans. 1867 ; 0. Thomas, "On the Homologies and Succession
of the Teeth in the Dasyuridae," Phil. Trans. 1887 ; ami "Catalogue of Mar-
supialia and Mouotremata in the British Museum," 1888.
CHAPTEE VII
THE SUBCLASS EUTHERIA AND THE ORDER EDENTATA
The whole of the remaining groups of mammals are included in a
single subclass, known by the names Eutheria, Monodelphia, or
Placentalia. 1 The one distinctive feature they have in common
(from which the last-mentioned name is derived) is the presence of
an allantoic placenta by means of which the foetus is nourished within
the uterus of the mother. Throughout the entire subclass, as a general
rule, the urino-genital organs open quite independently of the rectum ;
the corpus callosum of the brain is well developed ; the mandible does
not show a marked inflection of its angle ; and distinct epipubic
bones are not attached to the anterior margin of the pubic symphysis.
In those cases where there is a heterodont and diphyoclont dentition
the dental formula can be reduced to some modification of the one
given on p. 25, there being only one known genus Avhere four
true molars occur, and even that not invariably. As in the
Metatheria, the coracoid is reduced to a mere appendage of the
scapula, and the acetabular cavity of the pelvis is imperforate.
While the survivors of the other subclasses have probably been
for a long time in a stationary condition, these have, as there is
already good evidence to show throughout all the Tertiary
geological age, and by inference for some time before, been multi-
plying in numbers and variations of form, and attaining higher
stages of development and specialisation in various directions.
They consequently exhibit far greater diversity of external or
adaptive modification than is met with in either of the other sub-
classes, — some being fitted to live as exclusively in the water as
fishes, and others to emulate the aerial flight of birds.
To facilitate the study of the different component members
of this large group, it is usual to separate them into certain
1 The characters of the chief groups of the Eutheria here given are, in some
measure, a fuller recapitulation of those already detailed in Chapter III., pp.
83-88.
174 EUTHERIA
divisions which are called " orders." In the main zoologists
are now of accord as to the general number and limits of these
divisions among the existing forms, but the affinities and relation-
ships of the orders to one another are far from being understood, and
there are very many extinct forms already discovered which do not
fit at all satisfactorily into any of the orders as commonly defined.
Commencing with the most easily distinguished, we may first
separate a group called Edentata, composed of several very distinct
forms, the Sloths, Anteaters, and Armadillos, which under great
modifications of characters of limbs and digestive organs, as well as
habits of life, have just enough in common to make it probable that
they are the very specialised survivors of an ancient group, most
of the members of which are extinct, although the researches of
palaeontology have not yet revealed them to us. The characters of
their cerebral, dental, and in many cases of their reproductive organs
show an inferior grade of organisation to that of the generality of
the subclass. The next order, about the limits of which there is no
difficulty, is the Sirenia, — aquatic vegetable-eating animals, with
complete absence of hind limbs, and low cerebral organisation, —
represented in our present state of knowledge by but two existing
genera, the Dugongs and Manatees, and by a few extinct forms,
which, though approaching a more generalised mammalian type,
show no special characters allying them to any of the other orders.
Another equally well-marked and equally isolated, though far mure
numerously represented and diversified order, is that of the Cetacea,
composed of the various forms of Whales, Dolphins, and Porpoises.
In aquatic habits, external fish-like form, and absence of hind limbs,
they resemble the last, though in all other characters they are
as widely removed as are any two orders among the Eutheria.
All the remaining orders are more nearly allied together, the
steps by which they have become modified from one general
type being in most cases not difficult to realise. Their dentition
especially, however diversified in detail, always responds to the
formula already alluded to, and, although the existing forms are
broken up into groups in most cases easy of definition, the discoveries
already made in palaeontology have in great measure filled up the
gaps between them.
Very isolated among existing Eutheria are the two species of
Elephant constituting the group called Proboscidea. These, however,
are now known to be the survivors of a large series of similar animals,
Mammoths, Mastodons, and Dinotheres, which as Ave pass backwards
in time gradually assume a more ordinary or generalised type ; and
the interval which was lately supposed to exist between even these
and the rest of the class is partially bridged over by the discovery
in American Eocene and early Miocene formations of the gigantic
Dinocerata, evidently offshoots of the great group of hoofed animals,
ORDERS 175
or Ungulate, represented in the actual fauna by the Horses,
Rhinoceroses, Tapirs, Swine, and Ruminants. Almost as isolated
a> the Proboscidea anion,-; existing mammals are the few small
species constituting the family Hyracidce, and in their case palaeon-
tology affords no help at present, and therefore, pending further dis-
coveries, it has been thought advisable in most recent systems to
give them the honour of an order to themselves, under the name of
Hyracoidea. But the number of extinct forms already known allied
to the Ungulate, though not coming under the definition of either
of the two groups (Artiodactyla and Perissodactyla) under which all
existing species range themselves, is so great that either many new
orders must be made for their reception or the definition of the old
order Ungulate so far extended as to receive them all, in which
case both Proboscidea and Hyracoidea may be included within it.
Again, the Rodentia or gnawing animals — Rabbits, Rats, Squirrels,
Porcupines, Beavers, etc. — are, if Ave look only at the present state
of the class, most isolated. No one can doubt what is meant by a
Rodent animal, or have any difficulty about defining it clearly, at
least by its dental characters ; yet our definitions break down before
the extinct South American Typotkerium, half Rodent and half
Ungulate, which leads by an easy transition to the still more truly
Ungulate Toxodon, for the reception of which a distinct order
(Toxodontia) has been proposed. It has also been suggested that
the Rodents are connected by some of the extinct Tillodontia (or
Tseniodontia) with the Edentates. The Insectivora and the
Carnivora again are at present quite distinct orders, but they merge
into one another through fossil forms, and are especially connected
by the large group of primitive Carnivora, so abundantly repre-
sented in the Eocene deposits both of America and Europe, to which
Cope has given the name of Creodonta. The Carnivora also appear
to have been closely connected with the primitive Ungulates as repre-
sented by the extinct group called Condylarthra. In another
direction the step from the Insectivores to the Lemurs is not great,
and in past times the transition was probably complete. The Bats
or Chiroptera are allied to the Insectivora in all characters except the
extraordinary modification of their anterior extremities into wings;
but this, like the want of the hind limbs in the Cetacea and Sirenia,
makes such a clear distinction between them and all other mammals
that, in the absence of any knowledge of any completely inter-
mediate or transitional forms, they can be perfectly separated, and
constitute as well-defined an order as any in the class. We have,
however, an inkling of the mode in Avhich the Insectivora were
modified into Chiroptera shoAvn us by the so-called Flying Lemur
(Goleopithecus). Finally, Ave have the important and Avell-character-
ised group called Primates, including all the Monkeys and Man ;
and the question is not yet solved as to hoAv and through what
176 EDENTATA
forms this is linked on to the other groups. It is commonly assumed
that the Lemurs are nothing more than inferior Primates, but the
interval between them in the actual fauna of the world is very great,
and our knowledge of numerous extinct types recently discovered
in America, said to be intermediate in characters, is not yet
sufficient to enable us to form a definite opinion upon the subject.
The Edentata may be taken first as standing in some respects
apart from all the others ; and the Primates must be placed at the
head of the series. The position of the others is quite arbitrary, as
none of the hitherto proposed associations of the orders into larger
groups stand the test of critical investigation, and palaeontological
researches have already gone far to show that they are all modifica-
tions of a common heterodont, diphyodont, pentadactylate form.
Order Edextata.
The name assigned to this group (Avhich some zoologists think
ought rather to be ranked as a subclass 1 than an order) b}^ Cuvier
is often objected to as inappropriate — for although some of the
members are edentulous, others have very numerous teeth — and the
Linnaean name Bruta is occasionally substituted. But that term is
(piite as objectionable, especially since the group to which Linnaeus
applied it is by no means equivalent to the order as now understood,
as the names of the genera contained in it, viz. El&phas, Trickechus,
Bradypus, Myrmecqphaga, Munis and Dasypus, indicate. It contained,
in fact, all the animals then known which are comprised in the
modern groups of Proboscidea, Sirenia and Edentata together with
the Walrus, one of the Carnivora. If retained at all, it should
rather belong to the Proboscidea, as Elcphas stands first in the
list of genera in the Systema Natures. Cuvier's order included the
Ornithorhynchus and Echidna, the structure of which was then im-
perfectly known, and which are now by common consent removed
to an altogether different section of the class ; but otherwise its
limits are those now adopted. The name Edentata is so generally
used, and its meaning so well understood, that it would be un-
desirable to change it now ; in fact similar reasons might be assigned
for ceasing to use nearly all the other current ordinal designations,
for it might be equally well objected that all Carnivora are not
flesheaters, many of the Marsupialia have not pouches, and so
forth.
If the teeth are not always absent, they invariably exhibit
certain imperfections, which are indeed almost the only common
characters binding together the various extinct and existing members
of the order. These are — that they are homodont and, with the
1 The name Paratheria has Wen suggested for this proposed subclass.
uKXERA L CI I A RA CTERS
177
remarkable exceptions of Tatusia and Oryckropus, monophyodont ;
they are never rooted, but have persistent pulps ; except in some
fossil forms, they are always deficient in one of the constituents
which enter into the formation of the complete mammalian
tooth, the enamel : and, at least among living forms, are never
present either in the upper or lower jaw in the fore part of
the month, the situation occupied by the incisors of other
mammals. 1
The peculiar nature of the dentition in the aberrant Onjderopus
will be noticed under the heading of that
gem
As a rule, the
coracoid process of the scapula of the Edentates is more developed
than in other Eutheria.
The degree of development of the brain varies considerably in
the different families, the
hemispheres being in some
cases almost or quite smooth
(Fig. 57), with a small corpus
callosum, and large anterior
commissure ; while in other
instances the hemispheres
are convoluted, and the
corpus callosum is larger.
There is so great a differ-
ence in structure and habits
between some of the existing
animals assigned to this order
that, beyond the negative
characters just mentioned,
there seems little to connect
them. The Sloths and Anteaters, for instance, in mode of life,
general conformation of limbs, structure of digestive organs, etc.,
appear at first sight almost as widely separated as any mammals.
Paleontology has, however, thrown great light upon their relations,
and proved their real affinities. Perfectly intermediate forms have
been discovered in the great Ground Sloths of America, which have
the dentition and general form of the head of the Sloths, combined with
the limbs and trunk of the Anteaters. It is, indeed, highly probable
that the existing members of this order are very much differentiated
representatives of a large group, the greater number of which are
now extinct, and have become so without ever attaining a high
grade of organisation. The great diversity of structure in the
existing families, the high degree of specialisation to which many
have attained, the paucity of species and even of individuals, their
1 In some few Armadillos the suture between the premaxilla and maxilla
passes behind the first upper tooth ; but iu all other known members of the order
all the teeth are implanted in the maxilla.
12
Fig. 57. — Upper surface of the brain of the Broad-
banded Armadillo (Xenurus nnicinctus). The large
olfactory lobes are seen at the anterior extremity
(left of figure) ; the hemispheres have only three
sulci. (From Garrod, Proc. Zool. Soc. 1S7S, p. 230.)
178 EDENTATA
limited area of distribution, and their small size compared with
known ancestral forms, all show that this is an ancient and a waning
group, the members of which seem still to hold their own either by
the remoteness and seclusion of their dwelling-places, by their
remarkable adaptation of structure to special conditions of life, or
by aid of the peculiar defensive armature with which they are
invested. Their former history can, however, only be thus surmised,
rather than read, at present ; for, though we have ample evidence
of the abundance and superior magnitude of certain forms in the
most recent or Pleistocene geological age, yet Ave have at present
no definite evidence as to their origin, or relationship to other
orders of mammals.
The existing members of the order readily group themselves
into five distinct families, the limits of which are perfectly clear.
These are (1) Bradypodidce, or Sloths; (2) Myrmecophagidce, or Ant-
eaters ; (3) Dasypodidce, or Armadillos ; (4) Manidce, Pangolins or
Scaly Anteaters ; and (5) Orycteropodiclcc, Aard-varks or African
Anteaters. The geographical distribution of these families coincides
with their structural distinction, the first three being inhabitants of
the New and the last two of the Old World. It has been usual to
arrange these families into two large groups or suborders: (1) the
Phyllophaga, leaf -eaters, also called Tardigrada, containing the
Bradypodidoe alone; and (2) the Entomophaga, insect-eaters, or
Vermilingua, containing all the other families, from which some-
times the Orycteropodidce are separated as a third suborder under
the name of Effbdientia, or Tubulidentata. Such an arrangement
is, however, an artificial one, founded on superficial resemblance.
The bonds which unite the Manidce to the Myrmecophagidce are
mainly to be found in the structure of the mouth, especially the
extensile character of the tongue, the great development of the sub-
maxillary glands, and the absence of teeth. These characters are
exactly analogous to those found in the Echidna among Monotremes,
the Woodpeckers among Birds, and the Chamoeleon among Reptiles,
— the fact probably being that in countries where Termites and
similar insects flourish various distinct forms of vertebrates have
become modified in special relation to this abundance of nutritious
food, which could only be made available by a peculiar structure of
the alimentary organs. A close study of the more essential
portions of the anatomy of these animals l leads to the belief
that all the American Edentates at present known, however di-
versified in form and habits, belong to a common stock. Thus the
Bradypodidce, Megatheriidce, and Myrmecophagidce are certainly allied,
the modifications seen in the existing families relating only to food
and manner of life. The ancestral forms may have been omni-
1 See Flower, "On the Mutual Affinities of the Animals composing the
Order Edentata," Proceedings of the Zoological Society, 1882, p. 358.
BRADYPODIDjE 179
\ Mums, and gradually separated into the purely vegetable and
purely animal feeders; from the former are developed the modern
Sloths, from the latter the Anteaters. The Armadillos (Dasypodida )
are another modification of the same type, retaining some
generalised characters, as those of the alimentary organs, but in
other respects, as in their defensive armature, remarkably special-
ised. The two Old World families Manidce and Orycteropodidce are
so essentially distinct, both from the American families and from
each other, that it may even lie considered doubtful whether they
are derived from the same primary branch of mammals, or whether
they may not be offsets of some other branch, the remaining
members of which have been lost to knowledge. Further remarks on
this point are recorded under the description of the Orycteropodidce. 1
Family Bradypodid.e.
Externally clothed with long, coarse, crisp hair. Head short
and rounded. External ears inconspicuous. Teeth f in each jaw,
subcylindrical, of persistent growth, consisting of a central axis of
vaso-dentine, with a thin investment of hard dentine, and a thick
outer coating of cement ; without (so far as is yet known) any suc-
cession. Clavicles present. Fore limbs greatly longer than the
hind limbs. All the extremities terminating in narrow, curved
feet ; the digits never exceeding three in number, encased for
nearly their whole length in a common integument, and armed
with long strong claws. Tail rudimentary. Stomach complex. No
caecum. Uterus simple and globular. Placenta deciduate, dome-like,
composed of an aggregation of numerous discoidal lobes. Strictly
1 An attempt has been made to represent these views by the following
classification :
Order EDENTATA.
Suborder Pilosa.
Bradypodidce.
Megatheriidce.
My r mccophagidce.
Suborder Loricata.
Dasypodidce.
Suborder Squamata.
Manidce.
Suborder Tubulidentata.
Orycteropodidce.
It may be objected to this arrangement that the present divergence between
the Sloths and Anteaters is hardly sufficiently indicated by their association in
one suborder. — Flower, "On the Arrangement of the Orders and Families of
Mammals," Proc. Zool. Soc. 1883, p. 178.
i8o
EDENTA TA
arboreal in habits, vegetable feeders, and limited geographically to
the forest regions of South and Central America.
The Sloths, as the animals of this family are called on account
of the habitual sluggishness of their movements, are the most strictly
arboreal of all mammals, living entirely among the branches of
trees, usually hanging under them, with their backs downwards
(Fig. 58), and clinging to them with the simple hookdike organs to
which the terminations of all their limbs are reduced. When they
are obliged from any cause to descend to the ground, which they
rarely, if ever, do voluntarily, their limbs, owing to their unequal -
length and the peculiar conformation of the feet — which allows
the animals to rest only on the outer edge — are most inefficient
Fig. 5S. — Two-toed Sloth (Ch.olce.pus hoffmanni).
for terrestrial progression, and they crawl along a level surface
with considerable difficulty. Though generally slow and inactive,
even when in their natural haunts, Sloths can on occasions travel
with considerable rapidity along the branches ; and, as they do not
leap, like most other arboreal creatures, they avail themselves of
the swaying of the boughs by the wind to pass from tree to tree.
They feed entirely on leaves and young shoots and fruits, which
they gather in their mouth, the fore limbs aiding in dragging
boughs within reach, but not being used like hands, as they are by
monkeys, squirrels, etc. When sleeping they roll themselves up in
a ball, and, owing to the dry shaggy character of their hair, are
very inconspicuous among the mosses and lichens with which the
JiRADVPODIIh-K 181
trees of their native forests abound; the concealment thus afforded
being heightened in some species by the peculiar greenish tint
of the outer covering — very uncommon in mammals. This is not
due to the colour of the hair itself, but to the presence upon its
surface of an alga, the lodgment of which is facilitated by the fluted
or rough surface of the exterior of the hair, and the growth of which
i> promoted by the dampness of the atmosphere in the gloomy
tropical forests, as it soon disappears from the hair of animals kept
in captivity in England. Sloths are nocturnal, silent, inoffensive, and
solitary animals, and usually produce but one young at birth. They
appear to show an almost reptilian tenacity of life, surviving the
most severe injuries and large doses of poisons, and exhibiting
longer persistence of irritability of muscular tissue after death than
other mammals.
In the Bradypodidce, as well as in the Myrmecophagidce, the
testes are placed close to each other, tying on the rectum between
it and the bladder ; the penis is epiite rudimentary, consisting
of a pair of small corpora cavernosa, not directly attached by their
crura to the rami of the ischia, and having a glans scarcely larger
than that of the clitoris of most mammals, and, as in birds and
reptiles, without any true corpus spongiosum. In the females of
both families the uterus is simple and globular ; and the vagina, at
least in the virgin state, is divided into two channels by a strong
median partition. The deciduate placenta of Cholcepus is composed
of a number of lobes aggregated into a dome-like mass : and it
does not appear that the placenta of the Anteaters departs in any
important characters from this type. According to the late Pro-
fessor W. K. Parker, the embryos of the Sloths, Anteaters, and
Pangolins have the stapes of the middle ear in the form of a rod,
thus showing affinities with a very primitive type of mammalian
organisation.
The Sloths Avere all included in the Linnaean genus Bradypus,
but Illiger very properly separated the species with but two claws
on the fore feet, under the name of Choice-pus, leaving Bradypus
for those with three.
Bradypus. 1 — Three-toed Sloths. Teeth usually f on each side ;
no tooth projecting greatly beyond the others ; the first in the
upper jaw much smaller than any of the rest ; the first in the
lower jaw broad and compressed ; the grinding surfaces of all much
cupped. Vertebra? : C 9, D and L 20 (of which 15 to 17 bear ribs),
S 6, Cll. All the known species present the remarkable pecu-
liarity of possessing nine cervical vertebrae, i.e. nine vertebrae
in front of the one which bears the first thoracic rib (or first
rib connected with the sternum, and corresponding in its general
relations with the first rib of other mammals) ; but the ninth.
1 Linn. Hyst. Nat. 12tli ed. vol. i. p. 50 (1766).
182
EDENTA TA
and sometimes the eighth, bears a pair of short movable ribs.
The arms or fore limbs are considerably longer than the hind
legs. The bones of the fore arm are complete, free, and capable of
pronation and supination. The hand is long, very narrow, habit-
ually curved, and terminates in three pointed curved claws, in
close apposition with each other. The claws are, in fact, incapable of
being divaricated, so that the hand is reduced to the condition of a
triple hook, fit only for the function of suspension from the boughs
of trees. The foot closely resembles the hand in its general struc-
ture and mode of use ; the sole being habitually turned inwards, so
that it cannot be applied to the ground in walking. The tongue is
short and soft, and the stomach large and complex, bearing some
resemblance to that of the ruminating Ungulates. The windpipe
or trachea has the remarkable peculiarity among mammals — not
unfrequent among birds and reptiles — of being folded on itself
before it reaches "the lungs. The mammae are two, and pectoral in
position.
" Ai " is the common name given in books to the Three-toed
Sloths. They were all comprised by Linnaeus under the species
Bradypus tridadylus. More recently Dr. Gray described as many
as eleven species, ranged in two genera, Bradypus and Arctopithecus ;
but the distinctions which he assigned both to species and genera do
not bear close examination. Some are covered uniformly with a
gray or grayish-brown coat ; others have a dark collar of elongated
hairs around the shoulders (B. torqmtus) ; some have the hair of
the face very much shorter than that of the rest of the head and
neck ; and others have a remarkable-looking patch of soft short hair
on the back between the shoidders, consisting, when best marked,
of a median stripe of glossy black, bordered on each side by bright
orange, yellow, or white. There are also structural differences in
the skulls, as in the amount of inflation of the pterygoid bones,
which indicate real differences of species ; but the materials in our
museums are not yet sufficient to correlate these with external
characters and geographical distribution. The habits of all are
apparently alike. They are natives of Guiana, Brazil, and Peru,
and one if not two species (B. infuscatus and B. castanekeps) extend
north of the Isthmus of Panama as far as Nicaragua. Of the
former of these Dr. Seeman says that, though generally silent,
a specimen in captivity uttered a shrill sound like a monkey
when forcibly pulled away from the tree to which it was
holding.
Cholcepus. 1 — Teeth £ ; the most anterior in both jaws separated
by an interval from the others, very large, caniniform, wearing
to a sharp, bevelled edge against the opposing tooth, the upper
shutting in front of the lower when the mouth is closed (Fig. 59),
1 Illiger, I'rodromus Syst. Mamm. d Actum, p. 108 (1811).
MEGATHER11P.E
183
unlike the true canines of heterodont mammals. Vertebrae: C6
or 7, l> 23-24, L :?, S 7-8, C4-6. One species (C. didactylus) has
the ordinary number of vertebrae in the neck; but an otherwise
closely allied form (C. hoffmanni) has but six. The tail is very
rudimentary. The hand generally resembles that of Bradypus; but
there are only two functional digits with claws — those answering
to the second and third of the typical pentadactylate manus. The
structure of the hind limb generally resembles that of Bradypus,
the appellation "two-toed" referring only to the anterior limb,
for in the foot the
three middle toes
are functionally
developed and of
nearly equal size.
C. didactylus, which
has been longest
known, is com-
monly called by
the native name
of Unau. It in-
habits the forests
of Brazil. G. hoff-
manni (Fig. 58)
has a more north-
ern geographical
range, extending
from Ecuador through Panama to Costa Rica. Its voice, which
is seldom heard, is like the bleat of a sheep, and if the animal is
seized it snorts violently. Both species are very variable in
external coloration.
Nothropus. 1 — The only fossil form which has been referred to
this family is indicated by a lower jaw, described by Dr. Burmeister,
from the Pleistocene of Argentina, which appears to have belonged
to an animal of about double the dimensions of Choloepus didactylus.
Professor Cope states, however, that this jaw really belongs to a
Glyptodont ; while it is referred by Dr. Ameghino to the next
family.
Fig. 59.— Skull of Two-toed Sloth (ChoUxpus didactylus).
Proc. Zool. Soc. 1871, p. 432.
From
Family Megatheriid^:.
The members of this family are all extinct. Their characters,
so far as is known from the well-preserved remains of many species
found abundantly in deposits of Pleistocene age in both North and
South America, were intermediate between those of the existing
Bradypodidce and the Myrmecophagida, combining the head and
1 Burmeister, Sitzb. Ak. Berlin, vol. xxviii. p. 613 (1882).
1 84
EDENTA TA
dentition of the former with the structure of the vertebral column,
limbs, and tail of the latter. Almost all the known species are of
comparatively gigantic size, the smallest, Nothrotherium escrivanense,
exceeding the largest existing Anteater, and the Megatherium
being larger than a Rhinoceros. The femur has no third trochanter,
and the odontoid process of the axis vertebra has a peculiar facet
on the ventral surface. The dentition is usually £ on each side, as
in the Sloths, but % in Nothrotherium. 1 This genus, and in a still
more marked degree Megatherium, diner from all the others in the
details of the structure of the teeth. They are very deeply
implanted, of prismatic form (quadrate in transverse section), and
the component tissues — hard dentine (Fig. 60, d), softer vaso-dentine
Fig. 60. — Section of upper molar teeth of Megatherium americanum. xj.
P, pulp-cavity ; the other letters explained in the text. (After Owen.)
(v), and cement (c) — are so arranged that, as the tooth wears, the
surface always presents a pair of transverse ridges, thus producing
a triturating apparatus comparable to the " bilophodont " molar of
Dinotherium, Tapirus, Manatus, Macrqpus, and others, though pro-
duced in a different manner. In all the other genera the teeth are
more or less cylindrical, though sometimes laterally compressed or
even longitudinally grooved on the sides, and on the grinding
surface the prominent ridge of hard dentine follows the external
contour, and is surrounded only by a thin layer of cement, as
in the existing Sloths. The Ground Sloths, as the members
1 Lydekker, in Nicholson and Lydekker's Manual of Palaeontology, vol. ii.
p. 1299 (1889). Originally described under the preoccupied name Ceelodon.
MEGA THERlin.E
185
of this family may be conveniently designated, agree with the
Sloths and Anteaters, and thereby ditler from all other mammals,
in that the coracoid process of the scapula and the coracoidal
border of the same unite over the coraco- scapular notch,
which is thus converted into a foramen. Large clavicles are
present.
Megatherium} — The typical genus Megatherium, as being the
longest known representative of the family, may be noticed in some
detail. A nearly complete skeleton, found on the banks of the
River Luxan, near Buenos Ayres, and sent in 1789 to the Royal
Museum at [Madrid, long remained the principal if not the only
source of information with regard to the species to which it belonged,
and furnished the materials for many descriptions, notably that of
Cuvier, who determined its affinities with the Sloths. 2 In 1832 an
important collection of bones of the Megatherium was discovered
near the Rio Salado, and secured for the Museum of the College
Fio. 01. — Oral surface of mandible of Megatherium americcmum.
a, Condyle ; b, masseteric process ; c, angle ; d, symphysis. (After Owen.)
of Surgeons of England ; and these, with another collection found
at Luxan in 1837, and now in the British Museum, supplied the
materials for the complete description of the skeleton published
by Sir R. Owen in 1861. Other skeletons have subsequently been
received by several of the Continental museums, as Milan and Paris,
and also by those in South America ; and consequently our know-
ledge of the organisation of the Megatherium, so far as it can be
deduced from the bones and teeth, is as complete as that of any
other animal, recent or extinct.
The remains hitherto spoken of are all referred to one species,
Megatherium americanum of Blumenbach (71/. cuvieri of Desmarest),
and are all from the newest or Pleistocene geological formations of
the Argentine Republic and Paraguay, or the lands forming the
1 Cuvier, Tableau EUm. d'Hist. Nat. des Animaux, p. 146 (1798).
- An excellent figure of this skeleton, which unfortunately was incorrectly
articulated, and wanted the greater part of the tail, was published by Pander
and D' Alton in 1821, and has been frequently reproduced in subsequent
works.
i86
E DENT A TA
basin of the Eio de la Plata. Dr. Leidy has described, from similar
formations in Georgia and South Carolina, bones of a closely allied
species, about one-fourth smaller, which he has named M. mirabile.
Three other South American species have been described ; but M.
laurillardi, of Lund, founded upon remains found in Brazil, has
been made the type of the genus Ocnopus.
The following description will apply especially to the best-known
South American form, Megatherium americanum. In size it exceeded
any existing land animal except the elephant, to which it was
inferior only in consequence of the comparative shortness of its
limbs ; for in length and bulk of body it was its equal, if not
Fig. G2. — Skeleton of Megatherium, from the specimen in the Museum of the Royal College
of Surgeons. x",V
superior. The full length of a mounted skeleton (Fig. 62), from
the fore part of the head to the end of the tail, is 18 feet, of which
the tail occupies 5 feet. The head, which is small for the size of
the animal, presents a general resemblance to that of the Sloth ;
the anterior part of the mouth is, however, more elongated, and the
jugal bone, though branched posteriorly in the same way as that of
the Sloth, meets the zygomatic process of the squamosal, thus
completing the arch. The lower jaw has the middle part of its
horizontal ramus curiously deepened, so as to admit of im-
plantation of the very long-rooted teeth, the peculiar structure
of which has been already described. A skull recently discovered
shows that, instead of the wide gap between the extremity of
the nasals and the premaxillse exhibited in Fig. 62, there was
a prenasal bone, towards which a process extended upwards and
MEGA THERIIDjE 187
1 iack wan Is from the extremity of the upper surface of the pre-
maxilhe.
The vertebral column consists of seven cervical, sixteen dorsal,
three lumbar, five sacral, and eighteen caudal vertebrae. The
spinous processes are much better developed than in the Sloths,
and are all directed backwards, there being no reversing of the
inclination near the posterior end of the dorsal series, as in most
active-bodied mammals. In the lumbar region, the accessory zyga-
pophyses, rudimentary in Sloths, are fully developed, as in the
Ant eaters.
The tail is large, and its basal vertebra? have strong lateral and
spinous processes and chevron bones, indicating great muscular
development. The scapula resembles that of the Sloths in the
union of the acromion with the coracoid, and in the bridging over
of the supra-scapular notch. The clavicle is complete and very
huge, much resembling that of man on a large scale. The fore
limbs are longer than the hind limbs. The humerus has no ent-
epicondylar foramen. The radius and ulna are both well developed,
and have a considerable amount of freedom of movement. The
hand is singularly modified. The pollex is represented only by a
rudimentary metacarpal, but the next three digits are large, and
terminate in phalanges adapted for the support of immense claws,
the middle one being especially large. The outer or fifth digit has
no claw, and it may be considered as certain that the weight of the
foot was, in standing and walking, chiefly thrown upon this one,
which was protected by a callous pad below, as in the existing
great Anteater, while the other toes were curved inwards towards
the palm, and only came in contact with the ground by their outer
surfaces. The mechanical arrangements by which the weight of the
body was thrown entirely upon the outer side of the foot are very
curious, and are fully described in Owen's memoir. The pelvis is
remarkably wide, even more so than that of the Elephant, but it is
formed on the same principle as in the Sloths. The femur is
extremely broad and flattened ; the tibia and fibula are short and
strong, and united together at each end. The hind foot, contrary
to the usual rule in the Edentata, is even more singularly modified
than the hand. Thus the ankle-joint is formed upon a peculiar
plan, quite unlike that of the Sloths, or of any other mammal, except
the Megatherium's nearest allies ; and the calcaneum projects nearly
as far backwards as the fore part of the foot does forwards. There
is no trace of great toe or hallux, or of its corresponding cuneiform
bone ; the second toe is rudimentary ; while the third has an enor-
mous ungual phalanx, which, as in those of the hand, is remarkable
for the immense development of the bony sheath reflected from
its proximal end around the base of the claw. The two outer toes
have large and very peculiarly-shaped metatarsals, but only small
1 88 EDENTATA
phalanges, and no claws. The creature probably walked upon the
outer edge of the sole, so that the great falcate claw of the third
toe did not come into contact with the ground, and so was kept in
a state of sharpness ready for use. The foot was therefore formed
upon quite a different principle from that of the Anteaters or
Sloths, though somewhat like the latter in having two of the toes
aborted.
Taking all the various points of its structure together, they
clearly indicate affinities both with the existing Sloths and with
the Anteaters, the skull and teeth more resembling those of the
former, and the vertebral column and limbs the latter. It is also
not difficult to infer the food and habits of this enormous creature.
That it was a leaf-eater there can be little doubt ; but the greater
size and more complex structure of its teeth might have enabled it
to crush the smaller branches as well as the leaves and succulent
shoots which form the food of the existing Sloths. It is, however,
very improbable that it climbed into the branches of the trees like
its diminutive congeners, and it is far more likely that it obtained
its subsistence by tearing them down with the great hook-like claws
of its powerful prehensile fore limbs, being easily enabled to reach
them by raising itself up upon the massive tripod formed by the
two hind feet, firmly fixed to the ground by the one huge falcate
claw, and the stout, muscular tail. The Avhole conformation of
the hinder part of the animal is strongly suggestive of such an
action. There can also be little doubt but that all its move-
ments were as slow and deliberate as those of its modern repre-
sentatives.
An idea at one time prevailed that the Megatherium was
covered externally with a coat of bony armour like that of the
Armadillos ; but this originated in dermal plates belonging to the
Glyptodon having been accidentally associated with bones of the
Megatherium. Similar plates, on a smaller scale, have indeed been
found in connection with the skeleton of the Mylodon, but never
yet with the Megatherium, which Ave may therefore imagine with
a covering of coarse hair like that of its nearest living allies, the
Sloths and Anteaters.
Scelidotheriv/m, Mylodon, etc. — Of the more important remaining
genera of this family a briefer notice will suffice. Scdidotherium (in
which Platyonyx may be included) comprises several species of
considerably smaller dimensions than the Megatherium, and is in
some respects intermediate between that genus and Mylodon. The
teeth have an oval cross-section, like those of the Sloths, while the
skull, in which the length of the nasals is subject to great variation
in the different species, approximates more or less closely to that
of the Myrmecophagidce. The humerus generally has an ent-
epieniiilylar foramen ; and the form and relations of the bones of
MEGA THERIIDAZ
1S9
Fig. 63.— Skeleton of Mylodon rolnistvs (Pleistocene, South
America). From Owen.
the feet differ considerably from those obtaining in the type genus.
S. l&ptoc&plmhim, the type of the genus, occurs in Patagonia and
Argentina but
other species are
found in Brazil
and Chili. The
genus Mylodon, in
its widest sense,
may he taken to
include a number
of comparatively
large Edentates,
some of which have
been described
under the names of
Grypotherium, Lest-
odon, and Pseudo-
lestodon. The teeth
of the upper jaw
are generally of an
oval or subtriangu-
lar section ; and in
the more typical forms the first and second teeth are separated
by a short interval, the former being horizontally worn. In
other species, however, like M. (Lestodon) armatus, there is a
considerable space between the first and second teeth, and the
first is worn obliquely. The skull is exceedingly like that of
the Sloths in general contour ; and there is not the descending
process at the angle of the mandible found in Megatherium.
The humerus has no entepicondylar foramen. The species
represented in Fig. 63 is from the Pleistocene of South America ;
but the type of the genus is M. harlani, from beds of corre-
sponding age in Kentucky. The Patagonian M. {Grypotherium)
darwini is a remarkable form, characterised by the presence of a
bony arch connecting the premaxillaB with the nasals, of which, as
already mentioned, there is an incomplete development in
Megatherivgn. Megalonyx, from the Pleistocene of Kentucky, differs
from Mylodon by the long interval between the first and second
teeth, and also by the presence of an entepicondylar foramen in
the humerus. NothrotheHum is a smaller form, occurring in the
deposits of the Brazilian caves, of which the dental features have
been already mentioned. The osteological characters of these and
other allied genera have been fully described in the works of
Cuvier, Owen, Burmeister. Leidy, Ameghino, Gervais, Bernhardt,
and others.
Promegathenum. — Two genera from the infra-Pampean beds
i go EDENTATA
of Argentina, described as Promcgatlierium and Promylodon, are
respectively distinguished from Megatherium and Myhdon by
the presence of bands of enamel on the teeth, which points
to the descent of the Edentates from mammals with enamelled
teeth.
The Tertiary North American forms described as Moropus and
Morotherium, 1 and originally regarded as Edentates, would appear to
be aberrant Ungulates.
Family Myrmecophagid^:.
Externally clothed with hair. No teeth. Head elongated.
Mouth tubular, with a small terminal aperture, through which the
long, vermiform tongue, covered with the viscid secretion of the
enormous submaxillary glands, is rapidly protruded in feeding, and
withdrawn again Avith the adhering particles of aliment, which are
then sucked into the pharynx. Clavicles rudimentary. In the
manus, the third toe is greatly developed, and has a long falcate
claw; the others are reduced or suppressed. The pes has four or
five subequal digits with claws. Posterior dorsal and lumbar
vertebra?, with additional interlocking zygapophyses. Tail long,
sometimes prehensile. Uterus simple. Placenta dome -like or
discoidal. Brain fairly convoluted, and with a large corpus cal-
losum and anterior commissure. The animals of this family are
the "Anteaters" par excellence. They feed exclusively on animal
substances, mostly insects. One species is terrestrial, the others
arboreal ; none burrow in the ground. They are all inhabitants of
the Neotropical region.
The reproductive organs, as noticed on p. 181, are of the
same general type as in the Bradypodidce.
Myrmecophaga. 2 — Skull greatly elongated and narrow, its upper
surface smooth and cylindriform. Anteriorly the face is produced
into a long, tubular rostrum, rounded above and flattened below,
with terminal nares, and composed of the mesethmoid ossified
for more than half its length, the vomer, the maxilla?, and the long
and narrow nasal bones, the premaxilla? being extremely short and
confined to the margin of the anterior nares. The zygomatic arch
is incomplete, the styliform jugal only articulating with the maxilla
in front, and not reaching to the very short zygomatic process of
the squamosal. The lachrymal foramen is in front of the margin of
the orbit. There are no postorbital processes to the frontals, or any
other demarcation between the orbits and the temporal fossa?. Palate
extremely elongated, and produced backwards as far as the level of
1 See E. D. Cape, Amcr. Naturalist, vol. xxiii. p. 152 (1889).
2 Linn. Syst. Nat. 12th ed. vol. i. p. 51 (1766).
M \ 'RMECOPHA G/DsE i 9 1
the external auditory meatus by the meeting in the middle line of
the largely developed pterygoids. The glenoid fossa a shallow oval
facet, with its long diameter from before backwards. Mandible very
long and slender, with an exceedingly short symphysis, no distinct
coronoid process, and a slightly elevated, elongated, flattened, con-
dylar articular surface. Vertebra' : C 7, D 15-16, L 3-2, S 6, C 31.
Clavicles rudimentary. In the manus the first digit is very
slender, the second also slender, with compressed phalanges of nearly
equal length. The third digit is immensely developed ; though its
proximal phalanx is extremely short, its ungual phalanx is so long
that the entire length of the digit exceeds that of the second. The
fourth has a long and rather slender metacarpal, and three
phalanges diminishing in size, the ungual phalanx being very
small. The fifth has the metacarpal nearly as long, but not so
stout, as the fourth, and followed by two small phalanges, the last
rudimentary and conical. Claws are developed upon all but the fifth.
In walking the toes are kept strongly flexed, and have their points
turned upwards and inwards, the weight being supported upon a
callous pad over the end of the fifth digit, and by the dorsal sur-
faces of the third and fourth digits. The hind feet are short and
rather broad, with five subequal claws, the fourth the longest, the
first shortest ; the whole sole is placed on the ground in walking.
Body rather compressed, clothed with long, coarse hair. Tail
about as long as the body, and covered with very long hair ; not
prehensile. Ears small, oval, erect. Eyes very small. Stomach
consisting of a subglobular, thin -walled, cardiac portion, and a
muscular pyloric gizzard with dense epithelial lining. No ileo-
colic valve, and a short wide ill -defined ctecum. Mammae two,
pectoral.
There is one species, 1 M. jubata, the Great Anteater, or Ant
Bear (Fig. 64), measuring 4 feet in length without the tail, and
upwards of 2 feet in height at the shoulder. Its prevailing colour
is gray, with a broad black band, bordered with white, commencing
on the chest, and passing obliquely over the shoulder, diminishing
gradually in breadth as it approaches the loins, where it ends in a
point. It is extensively distributed in the tropical parts of South
and Central America, frequenting low swampy savannas along the
banks of rivers, and the depths of the humid forests, but is nowhere
abundant. Its food consists mainly of termites, to obtain which it
opens their nests with its powerful sharp anterior claws, and as the
insects swarm to the damaged part of their dwelling, it draws them
into its mouth by means of its long, flexible, rapidly -moving tongue
covered with glutinous saliva. The Great Anteater is quite terres-
trial in its habits, being never known to climb trees, nor does it
1 Professor Cope lias recently come to the conclusion that there are three
species ; but further evidence is required in support of this view.
192
EDENTA TA
burrow underground like the Armadillos. Though generally an
inoffensive animal, when attacked it can defend itself vigorously and
effectively with its sabre-like anterior claws. The female bears but
a single young at a birth.
The union of the pterygoids in the middle line to prolong the
narial passage is a character found elsewhere among existing mam-
mals only in the next genus, in one Armadillo (Taiusia), and in
certain Cetacea. The contrast in length between the skull of the
Great Anteater and that of the Sloth is, as Professor Parker observes,
very marked indeed ; the one being relatively the longest and the
W&£
fe|Sl is
p IG . 04.— The Great Anteater (Myrmecophagajubata). (From Sclater, List of Animals in
Zoological Society's Gardens, 1SS3, p. 190.)
other almost the shortest in the whole class. The small size and
incomplete development of the jugal bone in the zygomatic arch
affords another striking contrast to the Sloths (Fig. 59).
Tmnandua} — This genus closely resembles the last in anatomical
structure, but the head is much less elongated, the fur is short and
bristly, the tail tapering, prehensile, with the under side through-
out and the whole of the terminal portion naked and scaly. The
stomach is similar to that of Myrmecophaga, but with the muscular
pyloric gizzard not quite so strongly developed. There is a distinct
ileo-colic valve and a short globular caecum. The fore foot has a very
Luge claw on the third toe, moderate-sized ckws on the second and
1 Gray, Annals of Philosophy, new series, vol. x. p. 343 (1S25).
.1/ ] 'lUfECOPIIA c ;// >. K
'93
fourth, a very minute one on the iirst, and none on the fifth, which
is entirely concealed within the skin. The hind foot has five
subequal claws. Vertebrae: C 7, I) 17, L 2, S 5, C 37. There are
very rudimentary clavicles.
The Tamandua (Fig. 65) is much smaller than the Great
Anteater. and differs essentially from it in its habits, being mainly
Fig. Cyj. — Tamandua Anteater {Tamaridwi tetrOdactyla). From Proc. Zool. Soc. 1S71, pi. xliii.
arboreal. It is an inhabitant of the dense primeval forests of
.South and Central America. As different individuals vary much
in their coloration, it is possible that there may be more than one
species. The usual colour is yellowish-white, with a broad black
lateral band, covering nearly the whole of the side of the body.
Cyrbitnru*} — The skull is much shorter even than in Tamandua,
and is arched considerably in the longitudinal direction. It differs
from that of the other members of the family mainly in the long
canal for the posterior nares not being closed by bone below, as
the greater part of the palatines and the pterygoids do not meet in
the middle line. The mandible has a prominent, narrow, recurved
coronoid, and a well-developed angular process ; it is strongly de-
curved in front. Vertebrae: C 7, D 16, L 2, S 4, C 40. Eibs
remarkably broad and flat. Clavicles well developed. Manus
remarkably modified, the third digit being greatly developed at the
expense of all the others, and having a stout short metacarpal and
but two phalanges, of which the most distal is large, compressed,
pointed, and much curved, and bears a very strong hook-like claw.
The second digit has the same number of phalanges, and bears a
claw, but is very much more slender than the third. The fourth
is represented only by the metacarpal and one nailless phalanx,
the first and fifth only by very rudimentary metacarpals. The pes
1 Gray, Annals of Philosophy, new series, vol. x. p. 343 (1825).
13
194
ED E NT A TA
is also completely modified into a climbing organ. The hallux is
rudimentary, consisting of a metatarsal and one phalanx, concealed
beneath the skin ; but the other four toes are subequal and much
curved, with long pointed compressed claws. The tuber calcanei is
directed towards the plantar surface, and parallel with it and
extending to about double its length is a greatly elongated sesamoid
ossicle. These together support a prominent calcarine cushion, to
which the nails are opposed in climbing. Stomach pyriform, with
muscular walls, but no distinct gizzard -like portion, as in the
foregoim
genera.
Commence-
ment of the colon provided with
two small caeca (Fig. 66), resem-
bling; those of many birds, narrow
at the base, and rather dilated
at their terminal blind ends, and
communicating Avith the general
cavity by very minute apertures.
Tail longer than the body, taper-
ing, bare on the under surface,
and very prehensile. Fur soft
and silky.
This genus has also but one
species certainly known, the Little or Two-toed Anteater (C. di-
dactylus), an animal not larger than a Rat, of a general yellowish-
colour, and exclusively arboreal in its habits. It is a native of
the hottest parts of South and Central America.
Fig. 66. — Caca of the Two-toed Anteater
(Cycloturus didactyhts). i, Ileum ; c, colon.
Family Dasypodid^e.
The greater part of the skin strongly ossified. On the back
and sides the union of numerous quadrate or polygonal scutes forms
a hard shield, usually consisting of an anterior (scapular) and
posterior (pelvic) solid portion (which overhang on each side the
parts of the body they respectively cover, forming chambers into
which the limbs are withdrawn), and a variable number of rings
between, connected by soft flexible skin so as to allow of curvature
of the body. The top of the head has also a similar shield
(cephalic), and the tail is usually encased in bony rings or plates.
The outer or exposed surfaces of the limbs are protected by irregular
bony scutes, not united at their margins ; but the skin of the inner
surface of the limbs and under side of the body is soft, and more or
less clothed with hair. Hairs also in many species project through
apertures between the bony scutes of the back. The ossified
dermal scutes are everywhere covered by a layer of horny epi-
dermis. Teeth numerous, simple, of persistent growth, and usually
dasypodidj: 195
monophyodont, lmt in one genus (Tatusia) a succession of teeth has
been observed. Zygomatic arch of skull complete. Cervical vertebrae
with extremely short, broad, and depressed bodies. The atlas free,
but the second and third, and often several of the others, anky-
losed together both by their bodies and arches. Lumbar vertebra?
with accessory zygomatic processes, and very large metapophyses,
supporting the bony carapace. Clavicles well developed. A third
trochanter on the femur. Tibia and fibula ankylosed at their distal
extremities. Fore feet with strongly developed, curved claws,
adapted for digging and scratching — three, four, or five in number.
Hind feet plantigrade, with five toes, all provided with nails.
Tongue long, pointed, and extensile, though to a less degree than
in the Anteaters. Submaxillary glands largely developed. Stomach
simple. Uterus simple. Placenta discoidal, deciduate. The brain
is generally characterised by the large size of the olfactory lobes
(Fig. 57), and the slight development of sulci on the hemi-
spheres ; the sylvian fissure being represented only by a very open
and shallow angle. From the earliest stage of development the
stapes is stirrup-shaped, thus showing a nearer affinity to the higher
mammals than is presented by the Sloths.
The animals of this family are commonly called Armadillos,
a word of Spanish origin, having reference to their armour -like
covering. The existing species are all of small or moderate size.
They are mostly, though not universally, nocturnal in their
habits, and are all omnivorous, feeding on roots, insects, worms,
reptiles, and carrion. Armadillos are harmless and inoffensive
creatures, offering no resistance when caught, their principal means of
escape from their enemies being the extraordinary rapidity with which
they can bui'row in the ground, and the tenacity with which they re-
tain their hold in their subterranean retreats. Notwithstanding the
shortness of their limbs they can run with great rapidity. Most of
the species are esteemed good eating by the natives of the countries
in which they live. They are all inhabitants of the open plains or
the forests of the tropical and temperate parts of South America,
with the exception of one species (Tatusia novem-cincta), which
ranges as far north as Texas. Of the existing genera, Chlamy-
dophorus stands apart from the rest in the formation of its external
covering ; but in all other respects Tatusia is the most aberrant
form, exhibiting a peculiar type of structure of the fore feet, which
in all the others show modifications, though in very varying degrees,
of a single and different type.
The reproductive organs of the Dasypodidce differ from those of
the Sloths and Armadillos in the presence of a largely developed
copulating organ in the male, and of a simple vagina of correspond-
ing length in the female. The testes are still abdominal, although
not in the same position ; and the penis still wants both the glans
1 96 EDENTATA
and bulb. The uterus is nearly or quite as simple as in the Sloths
and Anteaters ; and there is no reason to believe that the placenta-
tion is essentially different from that obtaining in the other groups.
Subfamily Chlamydophorinse. — In most anatomical characters,
especially the structure of the fore foot, this little group resembles
the Dasypodince; but it differs remarkably from all other knoAvn
Armadillos, living or extinct, in the peculiar modification of the
dermal armour.
Chlamydophmis. 1 — Teeth £ subcylindrical, somewhat com-
pressed, moderate in size, smaller at each end (especially in front)
than at the middle of the series. Skull broad and rounded behind,
pointed in front. Muzzle subcylindrical and depressed. A con-
spicuous rounded, rough prominence on the frontal bone, just before
each orbit. Tympanic prolonged into a tubular auditory meatus,
curving upwards round the base of the zygoma. Vertebra? : C 7,
D 11, L 3, S 10, C 15. Upper part of head and trunk covered with
four-sided horny plates (with very small thin ossifications beneath),
forming a shield, free, and overhanging the sides of the trunk, and
attached only along the middle line of the back. The plates are
arranged in a series of distinct transverse bands, about twenty in
number between the occiput and the posterior truncated end, and
not divided into solid thoracic and pelvic shields with movable
bands between. The hinder end of the body is abruptly truncated
and covered by a vertically-placed, strong, solid, bony shield, of an
oval (transversely extended) form, covered by thin epidermic plates.
This shield is firmly ankylosed by five bony processes to the hinder
part of the pelvis. Through a notch in the middle of its lower
border the tail passes out. The latter is rather short, cylindrical
in its proximal half, and expanded and depressed or spatulate in
its terminal portion, and covered with horny plates. The dorsal
surfaces of the fore and hind feet are also covered with horny
plates. The remainder of the limbs and under surface and sides
of the body beneath the overlapping lateral parts of the dorsal
shield are clothed with rather long, very soft, silky hair. Eyes and
ears very small, and concealed by the hair. Extremities short.
Feet large, each with five well-developed claws, those on the fore
feet very long, stout, and subcompressed, the structure of the digits
being essentially the same as those of Xenwms and Priodon. Nipples
two, pectoral. Visceral anatomy closely resembling that of Dasypus,
the caecum being broad, short, and bifid.
The Pichiciago (C. trukcatus), a small burrowing animal, about
5 inches long, inhabits the sandy plains of the western part of the
Argentine Republic, especially the vicinity of Mendoza. Its
1 Harlan, Ann. New York Lyceum Nat. Hist. vol. i. p. 237 (1824). —
Amended from Chiamyphorus.
DASYPODin.K 197
horny covering is of a pinkish colour, and its silky hair snow
white. It is rare, and its habits are but little known. A second
species, C. retusa, from Bolivia, has been described by Burmeister.
It is of rather larger size, and has the dorsal shield attached, to the
skin of the back as far as its edge, instead of only along the median
line.
Subfamily Dasypodinse. — Fore feet usually with all five digits
developed and with nails, though the first and fifth may be
suppressed. The first and second long and slender, with the
normal number and relative length of phalanges. The others stout,
with short broad metacarpals, and the phalanges greatly reduced
in length and generally in number by coalescence. The ungual
phalanx of the third very large, that of the others gradually
diminishing to the fifth. Dasypus, as now restricted, has the
most normal form of manus, but the modifications so markedly
developed in all the others (and culminating in Tolypeutes) are fore-
shadowed, as it were, in it. Ears wide apart. Mamma? one pair,
pectoral.
Dasypus. 1 — Teeth ^ or f, of which the anterior in the upper
jaw is usually imjilanted in the premaxillary bone. The series of
teeth extends posteriorly some distance behind the anterior root of
the zygoma, almost level with the hinder edge of the palate. They
are large, subcylindrical, slightly compressed, diminishing in size
towards each end of the series ; the anterior two in the mandible
much smaller, and more compressed than the others. Cranial
portion of the skull broad and depressed. Facial portion triangular,
broad in front and much depressed. Auditory bulla completely
ossified, perforated on the inner side by the carotid canal, and
continued externally into an elongated bony meatus auditorius, with
its aperture directed upwards and backwards. (In all the remain-
ing genera of Dasypodinai the tympanic bone is a mere half ring,
loosely attached to the cranium.) Mandible with a high ascending
ramus, broad transversely-placed condyle, and high slender coronoid
process. Yertebrse : C 7, D 11-12, L 3, S 8, C 17-19. Head broad
and flat above. Muzzle obtusely pointed. Ears of moderate size or
rather small, placed laterally, far apart. Body broad and depressed.
Carapace with six or seven movable bands between the scapular
and pelvic shields, each plate, or scute, being marked by a regular
ellipse formed of widely separated punctures. Tail shorter than
the body, tapering, covered with plates forming distinct rings near
the base. Fore feet with five toes ; the first much more slender
than the others, and with a smaller ungual phalanx and nail ; the
second, though the longest, also slender. The third, fourth, and
fifth gradually diminishing in length, all armed with very strong,
slightly curved, compressed claws, sloping away from an elevated
1 Linn. Syst. Nat, 12th ed. vol. i. p. 54 (1766).
i9§ EDENTATA
rounded inner border to a sharp, outer, and inferior edge. The
hind foot rather short, with all five toes armed with stout,
compressed, slightly curved, obtusely pointed claws — the third the
longest, the second nearly equal to it, the fourth the next, the first
and fifth shorter, and nearly equal.
To this genus belongs one of the best -known species of the
group, the Six -banded Armadillo or Encoubert (I), sexcinctiis) of
Brazil and Paraguay. A very similar species, 1). wMosiis, the Hairy
Armadillo, replaces it south of the Rio Plata. There are also two
very small species — D. veUerosus, from the Argentine Republic and
North Patagonia, and D. nrinutus from La Plata. The latter differs
from the other three in having no tooth implanted in the pre-
maxillary bone. Remains apparently referable to I). viUosus occur
in the Pleistocene cavern-deposits of Brazil.
Xenurus. 1 — Teeth •§■ or ||, of moderate size and subcylindrical.
The most posterior placed a little way behind the anterior root of the
zygoma, but far from the hinder margin of the palate. Cranium
somewhat elongated, much constricted behind the orbits, and
immediately in front of the constriction considerably dilated.
Mandible slender ; coronoid process very small and sharp-pointed,
sometimes obsolete. Vertebrae : C 7, D 12-13, L 3, S 10, C 18.
Head broad behind. Ears rather large and rounded, Avide apart.
Movable bands of carapace 12-13 ; the scutes being marked by an
obscurely granular sculpture. Tail considerably shorter than the
body, slender, and covered with nearly naked skin, with but a few
small, scattered, dermal bony plates, chiefly on the under surface
and near the apex. On the fore feet the first and second toes are
long and slender, with small claws and the normal number of
phalanges ; the other toes have but two phalanges ; the third has
an immense falcate claw ; the fourth and fifth similar but smaller
claws. The hind feet are comparatively small, with five toes, bearing
small, triangular, blunt nails ; the third longest, the first shortest.
The best known species of this genus, the Tatouay or Cabassou, A'.
unicinctus, is, after Priodon gigas, the largest of the group. It is
found, though not abundantly, in Surinam, Brazil, and Paraguay,
its remains occurring in the Pleistocene cavern-deposits of Brazil.
Others, A', hispidus and lufjubris, have been described, but little is as
yet known of them.
Priodon? — Teeth variable in number, and generally differing on
the two sides of each jaw, usually from 20 to 25 on each side
above and below, so that as many as 100 may be present alto-
gether ; but as life advances the. anterior teeth fall out, and all
traces of their alveoli disappear. The series extends as far back as
the hinder edge of the anterior root of the zygoma. The teeth are
1 Wagler, Syst. Amphibien, etc., p. 36 (1830).
- F. Cuvier, Hist. Nat. des Mammifires (1822). — Friodontcs.
DASYPODID^E 199
all very small ; those in the anterior half of each scries being strongly
compressed, with flat sides and a straight free edge ; the posterior
ones are more nearly cylindrical, with flat truncated, free surfaces.
Vertebrae: C 7, D 12, L 3, S 10, C 23. Head small, elongated,
conical. Ears moderate, ovate. Carapace with 12-13 movable
bands. Tail nearly equal to the body in length, gradually tapering,
closely covered with quadrangular scales, arranged in a quincunx
pattern. Fore feet with five toes, formed on the same plan as those
of A"' 11 urns, but with the claw of the third of still greater size, and
that of each of the others, especially the fifth, proportionately reduced.
Hind foot short and rounded, with five very short toes, with short,
broad, flat, obtuse nails. The only known species, the Great
Armadillo (P. gigas), is by far the largest of existing members of the
family, measuring rather more than 3 feet from the tip of the nose
to the root of the tail, the tail being about 20 inches long. It
inhabits the forests of Surinam and Brazil. The powerful falcate
claws of its fore feet enable it to dig with great facility. Its food
consists chiefly of termites and other insects, but it is said to attack
and uproot newly -made graves for the purpose of devouring the
flesh of the bodies contained in them.
TnJjipeufcs. 1 — Teeth § or -|, rather large in proportion to the size
of the skull, the hinder end of the series reaching nearly to the
posterior margin of the palate. Vertebra?: C 7, D 11, L 3, S 12,
C 13. Ears placed low on the sides of the head, rather large,
broadly ovate. Carapace Avith its scapular and pelvic shields very
free at the sides of the body, forming large chambers into which the
limbs can be readily withdrawn. Only three movable bands ;
sculpture of scutes in the form of subconcentrically arranged
granules. Tail short, conical, covered with large bony tubercles.
The fore feet formed on the same type as in the last genus, but the
peculiarities carried out to a still greater extent. The claw of the
third toe is very long and falcate, the first and fifth greatly reduced
and sometimes wanting. On the hind foot the three middle toes
have broad, flat, subequal nails, forming together a kind of tripartite
hoof ; the first and fifth much shorter, with more compressed
nails.
The Armadillos of this genus have the power of rolling them-
selves up into a perfect ball, the shield on the top of the head and
the tuberculated dorsal surface of the tail exactly fitting into and
rilling up the apertures left by the notches at either end of the
carapace. This appears to be their usual means of defence when
frightened or surprised, as they do not burrow like the other
species. They run very cpiickly, with a very peculiar gait, only
the tips of the claws of the fore feet touching the ground. Three
species are described: — T. fririncfus, the Apar ; T. conwus, the
1 Illiger, Prodromus Syst. Mamm. ct Avium, p. Ill (1811).
200
EDENTA TA
Matico ; and T. muriei. Remains apparently referable to T. conurus
are of not uncommon occurrence in the Brazilian cavern-deposits.
Subfamily Tatusiinse. — This group contains but one genus,
Tatusia. 1 Teeth § or f, very small subcylindrical. The first and
second subcompressed, the last considerably smaller than the others.
They present the remarkable peculiarity (elsewhere found among
Edentates, so far as is yet known, only in Oryderopus) of all being,
with the exception of the last, preceded by two-rooted milk teeth,
which are not changed until the animal has nearly attained its full
size. Vertebras: C 7, D 9-11, L 5, S 8, C 20-27. Head narrow,
with a long, narrow, subcylindrical, obliquely -truncated snout;
pterygoids meeting in the middle line below the nasal passage. Ears
rather large, ovate, and erect, placed close together on the occiput.
Fig. 67. — The Peba Armadillo (Tatusia novemcincta).
Carapace with seven to nine distinct movable bands ; sculpture on
scutes consisting of pits arranged in a V-shape. Body generally
elongated and narrow. Tail moderate or long, gradually tapering ;
its dermal scutes forming very distinct rings for the greater part of
its length. Fore feet with four visible toes, and a concealed clawless
rudiment of the fifth. Claws all long, slightly curved, and very
slender, the third and fourth subequal and alike, the first and fourth
much shorter. Hind feet with five toes, all armed with strong,
slightly curved, conical, obtusely-pointed nails. The third longest,
then the second and fourth; the first and fifth much shorter than
the others.
This genus differs from all the other Armadillos in having a pair
of inguinal mammae, in addition to the usual pectoral pair, and in
1 Lesson, Man. de Mammalocjic, p. 309 (1S27); ex. F. Cuvier, Tatusic.
DASYPODIDjE 201
producing a large number (four to ten) of young at a birth, all the
others having usually but one or two.
The Peba Armadillo, T. novemcincta (Fig. G7), is a well -known
species, having an extensive range from Texas to Paraguay. It is
replaced in the more southern regions of South America by a smaller
species, with shorter tail, the Mulita (T. hybrida), so called from the
resemblance of its head and ears to those of a mule. T. kappleri is
a large species from Surinam.
A rare Armadillo from Peru described under the names of Crypto-
phractus pilosus and Praopm hirsutus, but which evidently belongs to
Tatusia, is of some interest owing to the thick coat of hair with
which it is covered. This animal appears to be closely allied to
T. novemcincta, from which it mainly differs by having the whole of
the carapace covered with a thick coating of light brown, fine, but
rather stiff" hair, about an inch and a half in length. Similar hair
is found on the cheeks, the proximal portions of the limbs, and
(although less abundantly and shorter) on the under surface of the
body. The cephalic shield, snout, feet, and the tail, with the
exception of the root, are bare. The coating of hair on the back
and sides completely conceals the carapace, except near the margin
of the scapular region ; but by separating the hairs the bands and
scutes are rendered visible. 1
In the Pleistocene cavern -deposits of Brazil have been found
remains of T. novemcincta, and also of T. punctata, which appears to
be an extinct form nearly allied to T. Jcappleri, but of somewhat
larger size.
Extinct genera. — In addition to remains referable to existing
genera, the above-mentioned deposits have also yielded evidence
of the former existence of extinct generic types of Armadillos,
some of which attained very large dimensions. Of these Eutatus
was a large form distinguished from all existing genera by the
circumstance that the whole of the carapace was composed of mov-
able bands, which were thirty-three in number. Dasypoiherium
was a still larger form, furnished with eight teeth, of which the
second seems to have been larger than the others ; this genus is
regarded as connecting the modern Armadillos with the next one.
The gigantic Ghlamydotherw/m, the scutes of which are common in
the Brazilian caves, is considered to have been as large as a
Rhinoceros ; the carapace has several movable bands, but the teeth
1 A single imperfect skin, brought from the province of Ceara in Brazil, indi-
cates a very remarkable form of Armadillo, named by A. Milne-Edwards Sclero-
pleura brunetti {Ann. Sc. Nat. xvi. p. S, 1S72). The dermal scutes are said to
be much less developed than in other members of the family, and confined to the
sides, all the median portion of the back being clothed with a flexible hairy skin.
The head is broad and short, the ears small and far apart. The tail is long, and
almost entirely devoid of scutes. The feet are unknown.
202
E DENT A TA
approximate in structure to those of the next family, so that the
genus tends to connect the Armadillos with the Glyptodonts.
Family GiYPTODONTIDiE.
In the Pleistocene cavern -deposits of Brazil, but still more
abundantly in the flnviatile deposits which cover the country in the
neighbourhood of Buenos Ayres, are found the remains of some of the
most remarkable forms of mammals yet discovered, the Glyptodonts,
which may be regarded as forming a separate
extinct family. They differ from the existing
Dasypodidce in their large size, and in having the
carapace composed of a solid piece (formed by
the union of a multitude of bony dermal scutes)
without any movable rings, and in usually hav-
ing also a ventral piece or plastron. The facial
portion of the skull is very short. A long
process of the maxillary bone descends from
the anterior part of the zygomatic arch. The
ascending ramus of the mandible is remarkably
high. The teeth are £ in the known species,
all much alike, having two deep grooves or
rlutings on each side, so as to divide them into
three nearly distinct lobes (Fig. 68). The verte-
bral column is almost entirely ankylosed into
a solid tube, and there is a complex joint at the
base of the neck, to allow of the head being
retracted within the carapace. The limbs are
very strong, and the feet short and broad,
resembling externally those of an elephant or
tortoise. This family is mainly characteristic
of the southern half of the American continent,
but some species of the type genus ranged into
Texas and Mexico. Many species of the family
have been described and figured, especially by
Burmeister (in the Annales del Museo publico de
Buenos Aires), among which the following may
be noticed. Hoplophorm is characterised by the sculptured and
frequently thin scutes of the carapace, those of the periphery being
Hat, and not raised into prominences. The caudal sheath has
several overlapping movable rings at the base, and ends in a long
subcylindrical terminal tube similar to the one represented with the
carapace of Glyptodon in Fig. 69, Avhich in all probability really belongs
to the genus under consideration. Each foot has four complete
digits, and the humerus has an entepicondylar foramen. Most of the
Fig. OS.— Tooth of Chip.
from the side, and
from the grinding surface.
(After Owen.)
GLYPTOPOXTID.E
203
species are of medium size. Part of a caudal tube from Uruguay
described as Eleutherocercus indicates, however, a much larger allied
form, in which the tail appears to have had a number of stout bristles
protruding from the joints between the scutes. Panochtkus com-
prises very large ( ilvptodonts, distinguished by the great thickness
of the scutes of the carapace, which are ornamented with tubercles.
The termination of the caudal sheath forms a tube bearing large
radiated tubercles. Ewrywrus is distinguished by the radiate
sculpture of the scutes of the carapace. Dcedicwrus, of which one
species was about twelve feet in length, also has a rugose
sculpture on the carapace ; but the termination of the caudal tube is
expanded into a club-like shape, flattened from above downwards,
Fig. 69. — Glyptodon clavipes (Pleistocene, South America). From Owen. The tail is incorrectly
restored, and it is probable that the figured portion belongs to Hoplophorus. The left lower
corner shows an upper and a lower view of the skull, and the right a section of the caudal
sheath.
and covered with tubercles mingled with a few large radiate discs,
which, as in Panochthus, probably carried horny spines in the living
condition. The typical genus Glyptodon has each scute of the
carapace ornamented with a rosettedike sculpture, the peripheral
scutes being raised into conical prominences (Fig. 69). The caudal
sheath, instead of being like the one represented in the figure, Avas
entirely composed of a series of movable rings, ornamented with
Large tubercles. The manus had five digits, and the pes four; and
there was an entepicondylar foramen to the humerus. A species of
this genus, which attained very large dimensions, was made the
type of Schistopleurum, on the supposition that the tail of Glyptodon
was of the type represented in Fig. 69. The genus ITwroxophorus,
204 EDENTA TA
of the Pleistocene of South America, as well as Carioderma, of the
Pliocene of Texas, differ from all the preceding in having the scutes
of the carapace in the form of disconnected nodules. Glyptodonts
also occur in South American beds of earlier age than the Pleistocene,
some of these forms having enamel bands on the teeth. " Why such
a form as the Glyptoclon should have failed to keep his ground is,"
as the late Professor W. K. Parker remarks, " a great mystery ;
nature seems to have built him, as Rome was built, for eternity."
Fa mihj Manid.e.
Covered externally (except the under surface of the body and
inside of the limbs) with large imbricated horny scales, and
scattered hairs growing in the intervals. No teeth. Tongue long,
vermiform, and protractile. No accessory articular processes to
the lumbar vertebrae, but the anterior zygapophyses largely de-
veloped and deeply concave, completely embracing the semicylindri-
cal surfaces of the posterior zygapophyses. Limbs short, with five
complete digits on each foot. Scaphoid and lunar bones of carpus
united. Uterus bicornuate. Placenta diffused and non-deciduate.
All the existing forms belong to the Ethiopian and Oriental regions
of the Old World. The absence of additional articular processes to
the lumbar vertebrae is a character in which this and the following
family differ from all the preceding forms.
Manis. 1 — Skull somewhat of the form of an elongated cone, with
the small end turned forwards ; very smooth and free from crests
and ridges. No distinction between the orbits and temporal fossae.
The zygomatic arch usually incomplete, owing to the absence of
the jugal bone. No distinct lachrymal bone. Palate long and
narrow. The pterygoids extend backwards as far as the tympanies,
but do not meet in the middle line below. Tympanic ankylosed to
the surrounding bones, and more or less bullate, but not produced
into a tubular auditory meatus. Rami of mandible very slender
and straight, without any angle or coronoid process. From near
the anterior extremity of the upper edge a sharp, conical, tooth-like
process projects upwards and outwards. No clavicles. No third
trochanter to the femur. Ungual phalanges bifid at their ter-
minations. Caudal vertebrae with very long, strong transverse
processes and numerous chevron bones. Tongue long, vermiform,
flattened towards the tip; its retractor or sterno- glossal muscles
arising from the hinder extremity of the immensely prolonged
ensiform cartilage of the sternum. Stomach with thick lining
membrane and muscular walls, and a special gland near the
middle of the great curvature, consisting of a mass of complex
1 Linn. Syst. Nat. 12th ed. vol. i. p. 52 (1766).
MANJD.-E 205
secreting follicles, the duets of which terminate in ;i common
orifice. No civcum. A gall-bladder. Head small, depressed,
narrow, pointed in front, with a very small mouth -opening.
Eyes and pinna of ear very small. Body elongated, narrow.
Tail more or less elongated, convex above, flat underneath. The
whole of the upper surface of the head, the upper surface and sides
of the body, the whole of the tail, and the outer sides of the ex-
tremities covered with large, overlapping, horny scales, but usually
with a few stifi' hairs growing between and projecting beyond
them. The sides and under surface of the head, the under surface
of the body, and the inner sides of the limbs without scales, but with
a rather scanty covering of hair. Limbs short. In walking the
dorsal surface and outer sides of the phalanges of the two outer
digits of the front feet alone rest on the ground, the points of the
nails turning upwards and inwards. The third toe the longest,
with a powerful compressed curved claw; the second and fourth
with similar but smaller claws, that of the pollex often almost
rudimentary. Hind feet plantigrade, with the hallux very short,
and the four other toes subequal, with moderate, curved, subcom-
pressed nails.
The reproductive organs of Munis are of a totally different
type from those of the families already noticed. The testes lie
in the inguinal canal ; and the penis is external and well developed.
The uterus is tndy bicornuate, the vagina not divided, and the
placenta diffused and non-deciduate. All the organs and fcetal
membranes are, indeed, formed very much on the plan of those
of the Ungulates, Avithout any trace of the special peculiarities
obtaining in the typical American Edentates.
The animals of this genus, which includes all the existing forms,
are called Pangolins or Scaly Anteaters, and are all of small or
moderate size, terrestial and burrowing, and feed mainly on termites.
Several of them can climb trees. Their length varies from 1 to 5
feet. They can roll themselves up in a ball when in danger. Their
peculiar elongated form, short limbs, long, gradually-tapering tail,
and scaly covering give them on a superficial inspection more the
appearance of reptiles than of mammals. The species are not
numerous, and may be divided into two groups distinguished by a
few not very important external characters ; these groups also coin-
ciding with the present geographical distribution of the genus.
These two groups, according to Mr. 0. Thomas, may be distinguished
as follows.
The Asiatic pangolins are characterised by having the central
series of body-scales continued quite to the extreme end of the tail,
by having many isolated hairs growing up between the scales of the
back, and by their small external ears. They all have a small
naked spot beneath the tip of the tail, which is said to be of service
2o6
ED E NT A TA
as an organ of touch. There are three species, viz. Manis javanica,
ranging from Burma, through Malacca and Java, to Borneo ; 31.
aurita,ioxmd in China, Formosa, and Nipal ; and the common Indian
Pangolin, 31. pentadactyla, distributed over the whole of India and
Ceylon. The African species have the central series of scales
suddenly interrupted and breaking into two at a point about 2 or 3
inches from the tip of the tail ; they have no hair between the
scales, and no external ear-conch. The following are the four species
belonging to this
7
group : — the
Long-tailed Pan-
golin (71/. mac-
rura), which has
a tail nearly twice
as long as its
body, and con-
taining as many
as forty -nine
caudal vertebrae,
being the largest
number known
among mammals ;
the White-bellied
Pangolin (31. tri-
cuspis), Fig. 70,
closely allied to
the last, but with
longer and tri-
cuspid scales, and
white belly hairs.
These two, like
the Indian species, have a naked spot beneath the tail tip, a char-
acter probably correlated with the power of climbing, and they
are, moreover, peculiar in having the outer sides of their fore legs
clothed with hair, all the other species being scaly there as else-
where. Lastly, the Short -tailed and the Giant Pangolins (31.
temmincki and gigantea), both of which have their tails covered
entirely with scales, and evidently never take to arboreal habits.
All the four species of the second group are found in the West
African region, one only, 31. temmincki, extending also into south
and eastern equatorial Africa.
According to Professor W. K. Parker, 1 who remarks upon the
peculiarly aberrant nature of the group, the horny scales of the
Pangolins really consist of cemented hairs. This writer states that
" in the early embryo lozenge-shaped tracts of skin are seen all over
1 Mammalian Descent, p. 95.
Fig. 70. — The White-bellied Pangolin (Manis tricuspis).
MAXin.K 207
its body, with linos; of thinner cuticle between. Under the micro-
scope, sections of these thicker tracts show that they are composed
of hue hairs, cemented together by a copious growth of epidermic
cells ; here and there larger hairs are seen, but these fail to reach
the surface, turning again towards the inside, like nails driven into
wood that is too hard for their points."
The same author also observes 1 that there are occasional in-
stances of the presence of eight cervical vertebra? in the Pangolins
— a feature which has been considered to indicate some former
genetic connection between this family and the Sloths.
The following account of the habits of Maui* tricustpis is given by
Mr. L. Fraser in his Zoologia Typica : —
"During my short residence at Fernando Po I succeeded in
procuring two living specimens of this animal. The individuals,
judging from the bones, were evidently not adult ; the largest
measured 30 inches in length, of which the head and body were
1 2 inches and the tail 1 8 inches. I kept them alive for about a
■week at Fernando Po, and allowed them the range of a room, where
they fed upon a small black ant, which is very abundant and trouble-
some in the houses and elsewhere. Even when first procured they
displayed little or no fear, but continued to climb about the room
without noticing my occasional entrance. They would climb up
the somewhat roughly -hewn square posts which supported the
building with great facility, and upon reaching the ceiling would
return head foremost ; sometimes they would roll themselves up
into a ball and throw themselves down, and apparently without
experiencing any inconvenience from the fall, which was in a
measure broken upon reaching the ground by the semi -yielding-
scales, which were thrown into an erect position by the curve of
the body of the animal. In climbing, the tail, with its strongly
pointed scales beneath, was used to assist the feet ; and the grasp
of the hind feet, assisted by the tail, was so powerful that the
animal would throw the body back (when on the post) into a
horizontal position, and sway itself to and fro, apparently taking-
pleasure in this kind of exercise. It always slept with the body
rolled up ; and when in this position in a corner of the building,
owing to the position and strength of the scales, and the power of
the limbs combined, I found it impossible to remove the animal
against its will, the points of the scales being inserted into every
little notch and hollow of the surrounding objects. The eyes are
very dark hazel, and very prominent. The colonial name for this
species of Manis is ' Attadillo,' and it is called by the Boobies,
the natives of the island, 'Gahlah.' The flesh is said to be
excedingly good eating, and is in great request among the
natives."
Ma/nimalian Descent, p. 99.
2o8 * EDENTATA
The Indian species is said to live in pairs, and to give birth to
one or two young at a time in the spring. Their burrow reaches a
depth of some twelve feet, and terminates in a large chamber, which
may be as much as six feet in diameter. A faint hiss appears to be
the only sound emitted by these animals.
Remains of a large species of Manis, which are indistinguishable
from the corresponding bones of the existing West African M.
giganiea, are found fossil in cave-deposits in the Karnul district of
Madras. This is one among several instances of the close connection
between the Pleistocene and Pliocene mammalian fauna of India Avith
the existing African fauna.
Palceomanis. 1 — The lower Pliocene deposits of the Isle of
Samos, in the Turkish Archipelago, have yielded remains of a
Pangolin fully three times the dimensions of M. gigantea, upon the
evidence of which the genus Palceomanis has been established.
Family Orycteropodid.e
External surface scantily covered with bristle-like hairs. Teeth
numerous, apparently heterodont, diphyodont, and of peculiar and
complex structure, being traversed by a number of parallel vertical
pulp-canals. Lumbar vertebrae with no accessory zygapophyses.
Femur with a third trochanter. Fore feet without pollex, but all
the other digits well developed, Avith strong moderate-sized nails,
suited to digging, the plantar surfaces of which rest on the ground
in walking. Hind feet with five subequal toes. Mouth elongated
and tubular. Tongue subvermiform. Uterus bicornuate. Placenta
broadly zonular. Feeding on animal substances. Terrestrial and
fossorial in habits. Now mainly limited to the Ethiopian region.
OrycterojM*. 2 — The total number of permanent teeth appears to
be from eight to ten in each side of the upper, and eight in the
lower jaw; but they are never all in place at one time, as the
small anterior teeth are shed before the series is completed behind.
In the adult they number usually five on each side above and beloAv,
of which the first two are simple and compressed, the next two
larger and longitudinally grooved at the sides, the most posterior
simple and cylindrical. The last three in either jaw having no
milk -predecessors, may be regarded as true molars. The structure
of all these teeth is quite peculiar among mammals, though
resembling that of some fishes. Their summits are rounded before
they are worn ; their bases do not taper to a root, but are evenly
truncated and continually growing. Each tooth is made Tip of an
aggregation of parallel dental systems, having a slender pulp-cavity
1 Forsyth-Major, Comptes /,'< ndus, vol. cvii. p. 1180 (188S).
- Geoffroy, Dicaih- PHlosopMque, 1795 {teste Agassiz).
ORYCTEROPODID.K 209
in the centre, from which the dentinal tubes radiate outwards, and
being closely packed together each system assumes a polygonal
outline as seen in transverse section. The small anterior teeth have
milk-predecessors which are fully noticed below. Skull moderately
elongated. The facial portion subcylindrical and slightly tapering.
The zygoma complete and slender. The palate ends posteriorly in
the thickened transverse border of the palatines, and is not
continued back by the pterygoids. The tympanic is annular, and
not ankylosed to the surrounding bones. The mandible is slender
anteriorly, but rises high posteriorly, with a slender recurved
coronoid, and an ascending pointed process on the hinder edge
below the condyle, which is small, oval, and looks as much forwards
as upwards. Vertebra?: C 7, D13, L 8, S 6, C 27. The large
number of lumbar vertebra? is peculiar among Edentates. Tongue
less vermiform than in Myrmeeophaga, being thick and fleshy at the
base, and gradually tapering to the apex. The salivary apparatus
is developed much in the same manner as in that genus, but the
duct of the submaxillary gland has no reservoir. The stomach
consists of a large subglobular cardiac portion, with a very thick,
soft, and corrugated lining membrane, and a smaller muscular,
pyloric part, with a comparatively thin and smooth lining. There
is a very distinct ileo-csecal valve, and a considerable-sized cascum ;
also a gall-bladder. Head elongated, with a tubular snout, terminal
nostrils, and small mouth-opening. Ears large, pointed, erect.
Tail nearly as long as the body, cylindrical, very thick at the base,
tapering to the extremity.
The reproductive organs and placentation of Orycteropus are
formed upon a principle unknown in the more typical Edentates,
or, in combination, in any other mammals. Thus the testes, in the
one described example, were inguinal, but appeared to descend, at
all events temporarily, into a scrotum ; but the penis is scarcely
larger than that of the Great Anteater. The uterus is still more
fully bicornuate than in Manis, with its two lateral chambers
opening separately into the vagina, as in certain Rodents. The
placenta is broadly zonary, but it is not known whether it is
deciduate or not. It might readily be derived from the diffused
placenta of Munis by the abortion of the foetal villi at the two poles
of the ovum.
The Oryderopodidce have long been regarded as widely different
from other Edentates, their presumed affinity with the Manidce
being more or less problematical ; but the discovery recently made
by Mr. 0. Thomas 1 that they have a milk-dentition still further
emphasises their aberrant nature. According to this observer, it
appears that there are normally no less than seven milk-teeth in the
upper jaw, the hindmost of which is far larger than the others,
1 Proceedings of the Royal Society, vol. xlvii. p. 246 (1890).
14
2io EDENTATA
having a rudimentary crown, and a distinct anterior and posterior
root. The other milk-teeth are styliform, the four anterior ones
being very minute, and separated from one another by equal
intervals ; the foremost of all is situated immediately behind the
premaxillo-maxillary suture. In the mandible only four milk-teeth
have hitherto been detected, of which the hindmost has the
comparatively complex form found in the corresponding upper tooth.
None of these milk-teeth appear, however, to cut the gum, so that
the whole set is entirely functionless. Under the microscope these
milk-teeth show signs of possessing a commencement of the
remarkable histological structure found in the permanent teeth.
Mr. Thomas remarks that since " the three large posterior teeth
of Oryderopus, already distinguished by their more molariform shape,
do not have milk-predecessors, while all the small teeth anterior to
them do, and in addition the last milk-tooth is markedly different
from those in front of it, we ought apparently no longer to look
upon this animal as an homodont, but instead to consider it as an
originally heterodont form in Avhich the incisors and canines have
been suppressed to allow free play to the mobile vermiform tongue.
"But important as a knowledge of the presence of a milk-
dentition in Oryderopus is, it does not at present render any easier
the difficult cpiestions as to the phylogeny and systematic position
of that animal. Although called an Edentate, it has always been
recognised as possessing many characters exceedingly different from
those of the typical American members of the order. It has in fact
been placed with them rather on account of the inconvenience of
forming a special order for its reception than because of its real
relationship to them. Now, as they are either altogether toothless,
or else homodont and monophyodont (apart from the remarkable
exception of Tatusia), it seems more than ever incorrect to unite
with them the solitary member of the Tubulidentata, toothed,
heterodont, and diphyodont, and differing from them in addition by
its placentation, the anatomy of its reproductive organs, the minute
structure of its teeth, and the general characters of its skeleton.
"But if Oryderopus is not genetically a near relation of the
Edentates, Ave are wholly in the dark as to what other mammals it
is allied to, and I think it would be premature to hazard a guess on
the subject. "Whether even it has any special connection with
Manis is a point about which there is the greatest doubt, and unfor-
tunately we are as yet absolutely without any paleeontological
knowledge of the extinct allies of either. Macrotherivm even,
usually supposed from the structure of its phalangeal bones, to be
related to Manis, has lately proved to have the teeth and vertebra?
of a perissodactyle Ungulate, and one could not dare to suggest
that ancestors of Manis, or Oryderopus were to be sought in that
direction. Lastly, as the numerous fossil American Edentates do
ORYCTEROPODID.E 211
not show the slightest tendency to an approximation towards the
Old World forms, we are furnished with an additional reason for
insisting on the radical distinctness of the latter, whose phytogeny
must therefore for the present remain one of the many unsolved
zoological problems."
The Aard -Yarks (Earth-Pigs) as these creatures are commonly
termed, from the name bestowed on them by the Dutch Boers of
the Cape, are of nocturnal habits, sleeping during the day in their
burrows, which are usually found in the neighbourhood of the tall
hills or mounds made by termites. Indeed, wherever these hills are
abundant it is stated there is a good chance of finding an Aard-Vark,
the food of these animals consisting almost exclusively of termites
and ants.
Tavo existing species are recognised, namely the Cape Aard-Vark
(0. afra) from South Africa, and another (0. cethiopicus) from the
north-eastern parts of Africa, ranging into Egypt. An extinct
species has been described from the Lower Pliocene of the Isle
of Samos, in the Turkish Archipelago, differing from the exist-
ing forms by the larger proportionate size of the lateral meta-
tarsals.
Bibliography of Edentata. — No general work on the order has been published
since that of Rapp (Anat. Untcrsuchungen iiber die Edcntatcn, 2d ed. 1852).
Among numerous memoirs on special groups the following may be cited : —
Myrmecophagidce : — R. Owen, "Anatomy of Great Anteater," Trans. Zool. Soc.
vol. iv. ; G. Pouchet, Mem. sur le Grand Fourmilicr, 1874 ; W. A. Forbes,
"Anat. of Great Anteater," Proc. Zool. Soc. 1882, p. 287. Megatheriidce .-— R.
Owen, Extinct Gigantic Sloth {Mylodon Robustus), 1842; Id., "On the Mega-
therium," Phil. Trans. 1851-56; J. Leidy, "Extinct Sloth -tribe of North
America," Smithsonian Contrib. to Knowledge, vii. 1855 ; H. Burmeister,
Description de la Republique Argentine, t. iii. Mammiferes, 1879,— which contains
full references to various memoirs by Owen, Gervais, Reinhardt, and others.
Hhiptodontidoz :— Owen, Catalogue of Fossil Mammals, Mus. Roy. Coll. Surgeons,
1845 ; T. H. Huxley, "Osteol. of Glyptodon, " Phil. Trans. 1865 ; H. Burmeister,
Annales del Museo Publico de Buenos Aires, and Dcscript. de la Republique
Argentine, 1879 ; H. Gervais and F. Ameghino, Les Mammiferes Fossiles de
VAmirique Meridionale, Paris, 1880,— which also contains a list of all the
S. American Edentates described at that date. Dasyp>odidce : — J. Murie, "Ana-
tomy of Tolypeutcs" Trans. Linn. Soc. vol. xxx. 1874 ; A. H. Garrod, Proc.
Zool. Soc. 1878. For Placentation of Edentates see W. Turner, Trans. Roy. Soc.
Edin. xxvii. (1873) p. 72, and Journ. Anat. and Physiol, vols. viii. and x. ; A.
Milne-Edwards, Ann. Sciences Nat. [6] viii. p. 1 ; and for brain, P. Gervais,
"Formes cerebrales des Edentes," Nouv. Arch, du Musi urn, torn. v. ; W. Turner,
Jour. Anatomy, i. 313 (1867). For the dentition of Orycteropus see 0. Thomas,
"A Milk Dentition in Orycteropus," Proc. Roy. Soc. vol. xlvii. p. 246 (1890).
Fuller observations on the mutual relations of the various families are given by
W. H. Flower, " On the Mutual Affinities of the Animals composing the Order
Edentata," Proc. Zool. Soc. 1882, p. 358.
CHAPTEE VIII
THE ORDERS SIRENIA AND CETACEA
Order SlRENTA.
The purely aquatic habits and fish-like form of the animals of this
order caused them to be formerly confounded with the Cetacea,
but a more intimate knowledge of their structure has shown that
they really belong to a widely different type of the mammalian
class.
The head is rounded and not disproportionate in size as com-
pared with the trunk, from Avhich it is scarcely separated by any
externally visible constriction or neck. Nostrils valvular, separate,
and placed above the fore part of the obtuse truncated muzzle.
Eyes very small, with imperfectly formed eyelids, capable, however,
of contraction, and with a well-developed nictitating membrane.
Ear without any pinna. Mouth of small or moderate size, with
tumid lips beset with stiff bristles. General form of the bod)"
depressed, fusiform. No dorsal fin. Tail flattened and horizontally
expanded. Fore limbs paddle-shaped, the digits being enveloped
in a common cutaneous covering, on which rudiments of nails are
sometimes present. No trace of hind limbs in existing forms. Ex-
ternal surface covered with a tough, finely wrinkled, or very
rugose skin, naked, or with fine hairs sparsely scattered over it.
The skeleton is remarkable for the massiveness and density of
most of the bones of which it is composed, especially the skull and
ribs, which must add to the specific gravity of these slow-moving
animals, and aid in keeping them to the bottom of the shallow
waters in which they dwell, while feeding on aquatic vegetables.
The skull presents many peculiarities, among which may be indicated
the large size and backward position of the anterior narial aperture,
a further modification of that met with in the Tapirs among Ungu-
lates, and presenting some approach to that so characteristic of the
Cetacea. The nasal bones are generally absent in the recent forms,
SIRE XI A 21.3
or are only found in a most rudimentary condition, attached to the
edge of the frontals, far away from the middle line; but in some at
Least of the extinct species these bones, though small in size, are
normal in situation and relations. In very few other respects does the
skull present any resemblance to that of the Cetacea. In the spinal
column of existing forms none of the vertebrae are united together
to form a sacrum, and the flat ends of the bodies do not ossify
separately, so as to form discdike epiphyses in the young state, as
in nearly all other mammals ; traces of epiphyses have, however,
been recently detected in Manatus, and they were fully developed in
Halitherium and other fossil forms. The anterior caudal vertebrae
have well-developed chevron bones. In one genus (Manatus) there
are only six cervical vertebra?. There are no clavicles. The humerus
has a small but distinct trochlear articulation at the elbow-joint.
The two bones of the forearm are about equally developed, and
generally ankylosed together at both extremities. The carpus is
short and broad, and the digits five in number, with moderately
elongated and flattened phalanges, which are never increased in
number beyond the limit usual in the Mammalia. The pelvis is
extremely rudimentary, consisting of a pair of bones suspended at
some distance' from the vertebral column. In no existing species
is there any trace of a hind limb, but in the extinct Halitheriwm
an acetabular depression and rudimentary femur have been dis-
covered.
Two kinds of teeth, incisors and molars, separated by a wide
interval, are generally present. The former may be developed into
tusks in the upper jaw, or may be quite rudimentary. The molars
vary much in character. In one genus (Bhytina) no teeth of any
kind are present, at least in the adult. Some fossil forms show a
more decidedly heterodont dentition, while Halitherium has milk-
teeth, of which no traces have been observed in the recent genera.
In all recent types the anterior part of the palate, and a corre-
sponding surface on the prolonged symphysis of the lower jaw, are
covered with rough horny plates of peculiar structure, which doubt-
less assist in mastication. The tongue is small and fixed in position,
with a surface resembling that of the plates just spoken of. The
salivary glands are largely developed. The stomach is compound,
being divided by a valvular constriction into two principal cavities,
the first of which is provided with a singular glandular pouch near
the cardiac end, and the second usually with a pair of elongated,
conical, crecal sacs or diverticula. The intestinal canal is lon°;, and
has very muscular walls. There is a caecum, either simple, conical,
and with extremely thick Avails, as in Halicore, or bifid, as in Manatus.
The heart is broad and flat, with its apex deeply cleft between the
ventricles. The principal arteries form very extensive and complex
retia mirabilia. The lungs are remarkably long and narrow, as,
214 SI RENT A
owing to the very oblique position of the diaphragm, the thoracic
cavity extends far back over the abdomen. The epiglottis and
arytenoid cartilages of the larynx do not form a tubular prolong-
ation as in the Cetacea, so that the epiglottis is not intranarial.
The brain is of comparatively small size, and the convolutions on
the surface of the cerebrum are few and shallow. The kidneys are
simple. The testes abdominal. The uterus is bicornuate. The
placenta (in the Dugong) is non-deciduate and zonary. The um-
bilical vesicle disappears early. The mammae are two, and pectoral,
or rather post-axillary in position.
The Sirenia pass their Avhole life in the water, being denizens of
shallow bays, estuaries, lagoons, and large rivers, but, unlike the
Cetacea, are not met with in the high seas, far away from the shore.
Their food consists entirely of aquatic plants, either marine algse or
freshwater grasses, upon which they browse beneath the surface, as
the terrestrial herbivorous mammals do upon the green pastures on
shore. They are generally gregarious, slow and inactive in their
movements, mild, inoffensive, and apparently unintelligent in dis-
position. Though occasionally found stranded by the tide or waves,
there is no satisfactory evidence that they voluntarily leave the water
to bask or feed on the shore. The habit of the Dugong of raising
its round head out of the water, and carrying its young under the
fore fin, seems to have given rise, among the imaginative early
voyagers in the Indian Ocean, to the legendary beings, half human
and half fish, in allusion to which the name Sirenia was bestowed by
Illiger on the order, though certainly the face of a Dugong, when
closely inspected, does not bear the slightest resemblance to that of
the mermaid of romance. The species now existing are very few,
and there is reason to believe that the time is not far distant when
they will all become extinct. One species, Rhytina stdleri, of the
North Pacific, was totally exterminated through the agency of man
during the last century ; and the others, being valuable for their
flesh as food, for their hides, and especially for the oil obtained from
the thick layer of fat which lies immediately beneath their skin,
rapidly diminish in numbers as civilised populations occupy the
regions forming their natural habitat. The surviving species are
confined to the tropical regions of the shores of both sides of the
Atlantic and the great rivers which empty themselves into that
ocean, and to the coasts of the Indian Ocean from the Red Sea to
North Australia. In the Miocene and early Pliocene epoch
Sirenians abounded in the seas of Europe, and their remains
have been found in deposits of corresponding periods in North
America. Evidence has also been discovered of the existence
of an animal of this group in the seas at the bottom of which
the Eocene nummulitic limestone mountain ranges of Egypt were
deposited.
MAX AT I IKK
215
The existing genera present such well-marked distinguishing
characters that it is on the whole convenient to place them in
separate families, although, as in so many similar cases, our know-
Ledge of the extinct forms, imperfect as it is, goes far to bridge over
the distinction between them.
Family Manatid.e.
The characters of this and the two following families may be
conveniently included under the heading of the single genus by which
they are respectively represented.
Manatus. 1 — Incisors -f, rudimentary, concealed beneath the horny
oral plates, and disappearing before maturity. Molars W, but
rarely more than -g- present at one time, the anterior teeth falling
before the posterior come into use ; similar in characters from
beginning to end of the series ; with square, enamelled crowns, the
grinding surface raised into tuberculated transverse ridges. The
upper teeth with two ridges and three roots, the lower teeth with
an additional (posterior) ridge, or talon, and two roots. The cer-
vical vertebra? present the remarkable anomaly of being reduced to
six in number, the usual vertebral formula being C 6, D 17, L 2,
and C 23-25. Rostrum of the skull, formed by the union of the
premaxillse in front of the anterior narial aperture, shorter than the
length of the aperture and scarcely deflected from the basi-cranial
axis ; premaxillae and mandibular symphysis not markedly deflected
(Fig. 72). Tail entire, rounded, or shovel- shaped. Rudimentary
nails on the fore limbs. Caecum bifid. Habitat the shores of,
and the great rivers which empty themselves into, the Atlantic
within the tropics. These animals are rather fluviatile than marine,
ascending large rivers almost to their sources.
The Manatee may be selected for a somewhat full description,
as being one of the best known representatives of this very remark-
able order.
The name Manati was apparently first applied to this animal by
the early Spanish colonists of the West Indies, in allusion to the
hand-like use which it frequently makes of its fore limbs ; by English
writers from the time of Dampier (who gives a good account of its
habits) downwards it has been generally spelt " Manatee." It was
placed by Linnaeus in his heterogeneous genus Trichechus, but Storr's
name Manatus is now generally accepted for it by zoologists. The
question of the specific distinction of the African and American
Manatees will be treated of ftuther on, but it will be chiefly to the
latter and better known form that the following description applies.
The size of the Manatee has been much exaggerated, but
1 Storr, Prodromus Meth. Marrvm. p. 41 (1780).
2l6
SIRENIA
there is no trustworthy evidence of its attaining a greater length
than 8 feet. Its general external form may be seen in Fig. 71,
taken from a living example in the Brighton Aquarium. The
body is somewhat fish-like, but depressed and ending posteriorly in
a broad, flat, shovel-like, horizontal tail, with rounded edges. The
head is of moderate size, oblong, with a blunt, truncated muzzle,
and divided from the body by a very slight constriction or neck.
The fore limbs are flattened oval paddles, placed rather low on the
sides of the body, and showing externally no signs of division into
fingers, but with a tolerably free motion at the shoulder, elbow,
and wrist joints, and with three diminutive flat nails near their
extremities. No traces of hind limbs are discernible either exter-
nally or internally ; and there is no dorsal fin. The mouth is very
peculiar, the tumid upper lip being cleft in the middle line into two
lobes, each of which is separately movable, as will be described in
speaking of its manner of feeding. The nostrils are two semilunar
■
IP
Pig. 71.— American Manatee (Manatus americanus), from life. Proc. Zool. Soc. 1S81, p. 457.
valve-like slits, at the apex of the muzzle. The eyes are very
minute, placed at the sides of the head, and with a nearly circular
aperture with wrinkled margins. The external ear is a minute
orifice situated behind the eye, without any trace of pinna. The
skin generally is of a dark grayish colour, not smooth and glistening,
like that of the Cetacea, but finely wrinkled. At a little distance
it appears naked, but a close inspection, at all events in young
animals, shows a scanty covering of very delicate hairs, and both
upper and under lips are well supplied with short stiff bristles.
The general form of the skull is seen in Fig. 72. The cerebral
cavity is rather small as compared with the size of the animal,
and of oblong form ; its roof is formed of the parietal bones as
in ordinary mammals. The squamosal has an extremely large
and massive zygomatic process, which joins the largely developed
jugal bone in front. The orbit is small, but prominent and
nearly surrounded by bone. The anterior nares taken together
form a lozenge-shaped aperture, which looks upwards and extends
M A NAT 1 DAI
2\J
backwards considerably behind the orbits. Their sides are formed
by the ascending processes of the premaxillse below, and by the
supraorbital processes of the frontals above, no traces of nasals
being found in most skulls, though these bones are occasionally
present in a most rudimentary condition, attached to the edges
of the frontals, far away from the middle line, in a position
quite unique among the Mammalia. In front of the narial aper-
ture the face is prolonged into a narrow rostrum, formed by
the premaxilla?, supported below and at the sides by the maxillae
The under surface of this is very rugose, and in life covered by a
horny plate. The rami of the mandible are firmly united together
at the symphysis, which is compressed laterally, slightly deflected,
and has a rugose upper surface ; to this another horny plate is
attached, which, with that of the upper jaw, functionally supplies the
Fin. 72. — Skull of African Manatee {Manatus senegalensis). I natural size.
From Mus. Roy. Coll. Surgeons.
place of teeth in the anterior part of the mouth. In the young
state there are rudimentary teeth concealed beneath these horny
plates, which never penetrate through them, and must therefore be
quite functionless, and altogether disappear before the animal is full-
grown. There is besides on each side of the hinder part of both
upper and lower jaws, a parallel row of molar teeth, similar in
characters from the beginning to the end of the series, with square
enamelled crowns raised into tuberculated transverse ridges, some-
thing like those of the Tapir and Kangaroo. The upper teeth have
two ridges and three roots ; the lower teeth have an additional
posterior small ridge or talon, and but two roots. These teeth
succeed each other from before backwards, as in the Proboscidea,
those at the front of the mouth being worn out and shed before
those at the back are fully developed. There are altogether about
eleven on either side of each jaw, but rarely more than six are
2i8 SIRENIA
present at one time. The brain is remarkably simple in structure,
its hemispheres exhibiting none of the richness of convolution so
characteristic of the Cetacea. The mammary glands of the female
are situated just behind and to the inner side of the origin of
the pectoral limb. The red corpuscles of the blood are among
the largest of those of any members of the class, averaging in
diameter, according to Gulliver, 3 / of an inch.
Manatees pass the whole of their life in the water, inhabiting
bays, lagoons, estuaries, and large rivers ; but the open sea, so con-
genial to the Cetacea, is quite unsuited to their peculiar mode of
life. As a general rule they prefer shallow water, in which, when
not feeding, they lie near the bottom, supporting themselves on the
extremity of the tail, or slowly moving about by the assistance of
the fore limbs, the tips of which are just allowed to touch the
ground, and only raising the top of the head above the surface for
the purpose of breathing at intervals of two or three minutes. In
deeper water they often float, with the body much arched, the
rounded back close to the surface, and the head, limbs, and tail
hanging downwards. The air in the lungs obviously assists them
to maintain this position, acting in the same manner as that in the
air-sac of fishes. Their food consists exclusively of aquatic plants,
on which they browse beneath the water. They are extremely
slow and inactive in their movements, and perfectly harmless and
inoffensive. Frequent attempts have been made to keep specimens
alive in captivity, and sometimes with considerable success, one
having lived in the Brighton Aquarium for upwards of sixteen
months. It was fed chiefly on lettuce and endive, but would also
eat leaves of the dandelion, sow-thistle, cabbage, turnip, and carrot.
From this and other captive specimens some interesting observations
upon the mode of life of the animal have been made. One of these
is the free use it makes of its fore limbs. From the shoulder-joint
they can be moved in all directions, and the elbow and wrist permit
of free extension and flexion. In feeding these creatures push the
food towards their mouths by means of one of the hands, or both
used simultaneously, and any one who has seen these members thus
employed can readily believe the stories of their carrying their
young about under their arms. Still more interesting and quite
unique among mammals is the action of the peculiar lateral pads
formed by the divided upper lip, thus described by the late Pro-
fessor Garrod : " These pads have the power of transversely
approaching towards and receding from one another simultaneously
(see Fig. 73, A and B). When the animal is on the point of seizing
(say) a leaf of lettuce, the pads are diverged transversely in such a
way as to make a median gap of considerable breadth. Directly
the leaf is within grasp the lip-pads are approximated, the leaf is
firmly seized between their contiguous bristly surfaces, and then
MAN ATI IKK
219
drawn inwards by a backward movement of the lower margin of
the lip as a whole." The animal is tlms enabled by the unaided
means of the upper lip to introduce food placed before it Avithout
the assistance of the comparatively insignificant lower lip, the action
greatly recalling to the observer that of the mouth of the silkworm
and other caterpillars, in which the mandibles diverge and converge
laterally during mastication. When out of water the Manatee is
an extremely helpless animal ; and, although statements are fre-
quently met with in books of its voluntarily leaving the water for
the purpose of basking or feeding on shore, all trustworthy ob-
servations of those acquainted with it, either in a state of nature
Fig. 73. — Front view of head of American Manatee, showing the eyes, nostrils, and mouth.
A, With the lobes of the upper lip divaricated ; B, with the lip contracted. From Murie,
Trans. Zool. Soc. vol. xi.
or in captivity, indicate that it has not the power of doing so.
None of the specimens in confinement have been observed to emit
any sound.
Manatees, though much less numerous than formerly, are still
occasionally found in creeks, lagoons, and estuaries in some of the
West India Islands, and at various spots on the Atlantic coast of
America from Florida as far south as about 20° S. lat., and in the
great rivers of Brazil, almost as high as their sources. They are
also met with in similar situations on the opposite African coast,
from about 16° N. to 10° S. lat., and as far into the interior as
Lake Tchad. Their range may even extend, if native reports
obtained by Schweinfurth are correctly interpreted, to the river
Keebaly, 27° E. long.
A considerable number of specific names have been applied to
the existing Manatees, but according to the researches of Dr.
Hartlaub x they may be reduced to three species, distinguished from
one another, among other features, by the characters of the skull,
and more especially the relations of the nasals to the adjacent
1 Zool Jahrbuch, vol. i. p. 1 (1886).
22o SIRENIA
bones. Of these the American Manatee may be known as M.
americanus, although it has been described under the names of
M. latirostris, and M. australis. The African Manatee (M. s&mgahtmi)
differs from the American species in the following cranial characters :
the anterior part of the rostrum is shorter, shallower, and altogether
smaller; the orbit is smaller; the zygomatic process is more deep
and massive ; the jugal bone is deeper from above downwards ; the
upper margin of the anterior nares is narrower and with a smooth
and rounded, instead of a thin and serrated, edge ; the upper surface
of the frontal is flat, instead of concave ; the foramen magnum and
occipital condyles are narrower from side to side, and the symphysis
of the mandible is smaller and shallower.
Finally, M. inunguis is a fluviatile species confined to the
Amazon and Orinoco, which has been but recently fully brought
under the notice of zoologists.
Family Halicorhle.
Halicore. 1 — In the upper jaw a pair of large, nearly straight, tusk-
like incisors, directed downwards and forwards, partially coated
with enamel. In the male they have persistent pulps, and bevelled
cutting edges, which project a short distance from the mouth, but
in the female, though they remain through life in the alveolar
cavity, they are not exserted, and, the pulp-cavity being filled with
osteodentine, they soon cease to grow (as in the female Narwhal).
In the young there is also a second small deciduous incisor on
each side above. At this age there are also beneath the horny plate
which covers the anterior portion of the mandible four pairs of
slender conical teeth lodged in wide alveolar depressions ; these
become absorbed before the animal reaches maturity. The molars
are usually |, sometimes f-, altogether, but not all in place at once,
as the first falls before the last rises above the gum ; they are more
or less nearly cylindrical in section (except the last, which is com-
pressed and grooved laterally), without distinction into crown and
root, increasing in size from before backwards, with persistent pulps
and no enamel. The summits of the crowns are tuberculated before
wearing, afterwards flattened or slightly concave. Skull with rostrum
formed by the union of the premaxillse in front of the narial
aperture, longer than the aperture itself, bending downwards at a
right angle with the basi-cranial axis, and enclosing the sockets
of the large incisor tusks. Anterior part of the lower jaw bent
down in a corresponding manner. Vertebrae : C 7, D 18-19, L and
C 30. Tail broadly notched in the middle line, and with two
pointed lateral lobes. No nails on the fore limbs. Csecura single.
1 Illiger, Prodromus Syst. Mamm. ct Avium, p. 140 (1S11).
RHYTINIDjE 221
The Dugongs are more distinctly marine in their habits than the
Manatees, feeding chiefly on sea-water algtc. They inhabit the
shallow bays and creeks of the Red Sea, east coast of Africa,
Ceylon, islands of the Bay of Bengal and the Indo- Malayan
Archipelago (including the Philippines), and the north coast of
Australia, ranging from Barrow Reefs on the west to Moreton Bay
on the east. Although the distinctive characters are not very
obvious, they have been divided into three species, according
to the localities which they respectively inhabit : — H. tabevnacnli
from the Red Sea, H. dugong from the Indian seas, and H. australis
from Australia. The last-named has lately been the object of a
regular "fishery," chiefly on account of its oil, Avhich is peculiarly
clear, limpid, and free from disagreeable smell, and is said to have
the same medicinal properties as cod-liver oil. Although often stated
in books to attain the length of 20 feet when adult, there does
not appear to be any evidence from actual specimens in museums
that Dugongs ever reach half that size, 8 feet being the common
length of adult animals.
The placentation of this genus has been recently described by
Sir W. Turner, who first indicated its zonary form.
Family Rhytinid.e.
Pihjitma} — No teeth, their place being supplied functionally by
the dense, strongly-ridged, horny oral plates. Premaxillary rostrum
about as long as the anterior narial aperture, and moderately
deflected. Vertebras : C 7, D 19, L and C 34-37. Head very small
in proportion to the body. Tail with two lateral pointed lobes.
Pectoral limbs small and truncated. Skin naked and covered with
a very thick, hard, rugged, bark-like epidermis. Stomach without
csecal appendages to the pyloric cavity. Cascum simple.
Only one species of this genus is known, R. stelleri, the Northern
Sea-cow, by far the largest animal of the order, attaining the length
of 20 to 25 feet. It was formerly an inhabitant of the shores of
two small islands in the North Pacific, Behring and the adjacent
Copper Island, on the former of which it was discovered by the
ill-fated navigator whose name the island bears, when, with his
accomplished companion, the German naturalist Steller, he was
wrecked upon it in 1741. Twenty-seven years afterwards (1768),
as is commonly supposed, the last of the race was killed, 2 and its
1 Illiger. Prodromus Syst. Me mm. et Avium, p. 141 (1811).— Amended from
Bytina.
2 Nordenskibld, during his voyage in the Vega, obtained some information
from the natives of Behring Island which led him to believe that a few individ-
uals may have survived to a much later date, even to 1854 ; but this conclusion
is disputed by later vmters.
SIRENIA
very existence would have been unknown to science but for the
interesting account of its anatomy and habits left by Steller, and
the few more or less imperfect skeletons which have recently re-
warded the researches carried on in the frozen soil of the islands
around which it dwelt. There is no evidence at present of its
having inhabited any other coasts than those of the islands just
named, although it can hardly be supposed that its range was
always so restricted. When first discovered it was extremely
numerous in the shallow bays round Behring Island, finding
abundant nutriment in the large laminarise growing in the sea.
Its extirpation is entirely due to the Russian hunters and traders
who followed upon the track of the explorers, and, upon Steller's
suggestion, lived upon the flesh of the great Sea-cows. Its
restricted distribution, large size, inactive habits, fearlessness of
man, and even its affectionate disposition towards its own kind
when wounded or in distress, all contributed to accelerate its final
extinction.
According to Steller's account, the Rhytina had a skin of a dark
brown colour, sometimes spotted or streaked with white. The fore
limb was covered with short brush-like hairs.
Extinct Sirenians.
Halitherium. 1 — The Miocene and early Pliocene seas of Europe
abounded in Sirenians, to which the generic name of Halitheriv/m
was given by Kaup, but which have also received other names.
They had large tusk-like incisors in the upper jaw, as in the
existing Dugongs, though not so greatly developed. Their molar
teeth were f or %, anteriorly simple and single-rooted, posteriorly
those above with three and those below with two roots, and with
enamelled and tuberculated or ridged crowns, in all which respects
they more resemble those of the Manatee than of the Dugong.
The anterior molars were deciduous ; and there is evidence of the
presence of milk-teeth. Germs of inferior incisors were also
present. Some species at least had nasal bones, short, broad,
but normal in position, whereas in all the existing genera these
bones are quite rudimentary. Another and still more important
evidence of conformity to the general mammalian type is the
better development of the pelvic bone, and the presence of a small
styliform femur articulated to the acetabulum, although no traces
of any other part of the limb have been discovered. These ancient
Sirenians, which may be regarded as representing a distinct family
— Halitheriidce — were thus, in dental, cranial, and other osteological
characters, less specialised than are either of the existing species,
1 Kaup, Neucs Jahrbuch, 183S, pp. 319 and 536.
HALITHERIID.E
223
Fio. 74. — The penultimate and last right lower molars
of Halitherium fossile ; from the Miocene of the Continent.
(After De Blainville.)
and if the intermediate links could be discovered might well be
looked upon as the ancestral forms from which the latter have been
derived, but at present the transitional conditions have not been
detected. So far as is yet known, when changes in the physical
conditions of the European seas rendered them unfitted to be the
habitation of Sirenians, the Halitherium type still prevailed. If the
existing Dugongs and Manatees are descended from it, their evolu-
tion must have taken place during the Pliocene and Pleistocene
epochs, the one in seas to the east, the other to the Avest of the
African continent, which has long formed a barrier to their inter-
communication. Halitherium remains have been found in many
parts of Germany, especially near Darmstadt, also in France, Italy
Belgium, Malta, etc.
Until a few years ago
none were known from
England, probably owing
to the absence of beds
of an age corresponding
to those in which they
are found on the Eu-
ropean continent ; but
a skull and several
teeth have been detected
among the rolled debris of which the Red Crag of Suffolk is partially
composed. The species are not yet satisfactorily characterised.
Some of them appear to have attained a larger size than the existing
Manatee or Dugong. One of these, from the Pliocene of Italy and
France, having but f molar teeth, has been separated generically
under the name of Felsinotherium by Capellini, by whom it has been
fully described ; but the difference in the number of the teeth
does not afford sufficient grounds for separation from Halitherium.
Miosiren of the Belgian Miocene, differs in that the last upper
molar is the smallest, in place of the largest of the whole series
of teeth.
Other forms. — Remains from the Pliocene of France described as
Prohalicore are regarded as indicating a Sirenian closely allied to
Halicore ; while a molar from the Tertiary of California has been
made the type of Desmotylus, which is likewise referred to the
Halicoridce. Dioplotherium, from the Phosphorites of South Carolina,
has been considered to connect Halicore with Halitherium, but even
its ordinal position is uncertain.
A portion of a skull found in the Pliocene of Belgium has been
described as Crassitherium by Van Beneden ; and some compressed
teeth, somewhat similar to but larger than those of the Dugong,
discovered in the Miocene of the department of Lot-et-Garonne,
France, gave origin to the genus Rytiodus of E. Lartet. Of this
224 SIRENIA
genus, which may be identical with Tradiytluriiun of the French
Miocene, better preserved remains have subsequently been described
by Delfortrie. These show that the rostrum is more elongated
than in Hal it lie riant, but the skull is otherwise very similar, as are
the molar teeth. The incisors are very large, exserted, strongly
compressed, almost sabre -like, rounded on the upper or anterior
surface, sharp below, concave on the external and convex on the
inner side, and transversely striated.
Parity acanthus from the Miocene of the Vienna basin is also, ac-
cording to Van Beneden, another form of Sirenian, of which, however,
the skull is not known. In various Miocene marine formations of
the United States of America other remains of Sirenians have
been found, but mostly in such a fragmentary condition that they
afford at present little evidence of the early history of the group
in that country. A more satisfactory discovery is that of a
nearly complete skull and some bones from a Tertiary limestone
formation in Jamaica. It is of smaller size than the Manatee,
and, so far as the teeth are concerned, of a still more generalised
character than HaUthcrium, the dentition being apparently i •§ , c \,
p + 111 ( ~~ ) = 48. The incisors are small, not developed into tusks ;
the canines (wanting in all existing Sirenians) are rather larger
than the incisors, judging by the sockets ; and the molars are
bilophodont, and covered with enamel. It has been described
by Sir E. Owen under the name of Prorastorms sirenoides. Some
writers regard this genus as the type of a distinct family — the
Prorastomatida 1 . Unfortunately we have no knowledge of the geo-
logical antiquity of the formation in which it was embedded. Lastly
must be mentioned the Eothcrium egyptiacurn, Owen, founded on the
cast of a brain, with a small quantity of surrounding bone, discovered
in the nummulitic limestone of Eocene age in the Mokattam Hills,
near Cairo. The brain is narrower than in Manafots, and resembles
that of Halitherium. This is of interest as the most ancient known
evidence of any Sirenian whose age has been geologically deter-
mined. Teeth from the same deposits referred to Manatus not
improbably belong really to Eotherium.
The few facts as yet collected relating to the former history of
the Sirenia leave us as much in the dark as to the origin and
affinities of this peculiar group of animals as we were when we only
knew the living members. They lend no countenance to their
association Avith the Cetacea, and on the other hand their supposed
affinity with the Ungulata, so much favoured by modern zoologists,
receives no very material support from them.
Bibliography of Sirenia.— J. F. Brandt, Symbolcc Sircnologicce, St. Petersburg,
3 fasciculi, 1846-61-68— an exhaustive account of the anatomy, affinities, and
literature of the group, with copious illustrations of the osteology of Bhytina.
CETACEA 2zs
Aa«t long : — Everard Borne, Phil. Trans. 1820, p. 315.; Owen, Proc.
Zool. Soc, 1838, p. 29. Placenta ofdo.:—W. Turner, Tram. Roy. Soc. Edm.
vol. xxxv. (1889). Manatee: — \Y. Vrolik, Bijdragem tot de Dierkunde, 1S51 ;
.1. .Miiiie, "On the Form ami Structure of the .Manatee," 'Trans. Zool. Soc. Loiul.
vol. viii. ]>. 127, 1872, ami " Further Observations on the Manatee," Ibid. vol.
xi. p. 19, 18S0 ; A. 11. Carrod, "Notes on the Manatee recently living in the
Zoological Society's Gardens," Ibid. vol. x. p. 137, 1875; II. C. Chapman,
"Observations on the Structure of the Manatee," Proc. Acad. Nat. Sciences of
Philadelphia, 1S7">. p. 452 ; A. Crane, "Notes on the Habits of the Manatees in
Captivity in the Brighton Aquarium," Proc. Zool. Soc. Lond. 1881, p. 456.
Extinct Sirenia: — Gervais, Journal dc Zoologic, torn. i. p. 332, 1872. R. Lydek-
ker, Catalogue of Fossil Mammalia in the British Museum, pt. v.
Order Cetacea.
This is perhaps the most distinctly circumscribed and natural
of all the larger groups into which the class is divided.
The external form is fish-like, the body being fusiform, passing
anteriorly into the head without any distinct constriction or neck,
and posteriorly tapering oft* gradually towards the extremity of the
tail, which is provided with a pair of lateral, pointed expansions of
skin supported by dense fibrous tissue, called "flukes," forming
together a horizontally-placed triangular propelling organ, notched
in the middle line behind.
The head is generally large, in some species attaining to even
more than one-third of the entire length of the animal, and the
aperture of the mouth is always wide, and bounded by stiff
immobile lips. The fore limbs are reduced to the condition of
flattened ovoid paddles, encased in a continuous integument, show-
ing no external sign of division into arm, fore arm, and manus, or of
separate digits, and without any trace of nails. There are no traces
of hind limbs visible externally. The general surface of the skin is
smooth and glistening, and devoid of hair, although in many species
there are a few fine bristles in the neighbourhood of the mouth,
which may either persist through life, or be present only in the
young state. Immediately beneath the skin, and intimately
connected with it, is a thick layer of fat, held together by a dense
mesh of areolar tissue, constituting the " blubber," which serves the
purpose of the hairy covering of other mammals in retaining the
heat of the body. In nearly all species a compressed median dorsal
tegumentary fin is present. The eye is small, and is not provided
with a nictitating membrane or true lachrymal apparatus. The
external auditory meatus is a very minute aperture in the skin
situated at a short distance behind the eye, and there is no vestige
of a pinna. The nostrils open either separately or by a single
crescentic valvular aperture, not at the extremity of the snout, but
near the vertex of the head.
15
CETACEA
The bones generally are spongy in texture, the cavities being
filled with oil. In the vertebral column the cervical region is
remarkably short and immobile, and the vertebra?, originally
always seven in number, are in many species more or less fused
together into a solid mass. The odontoid process of the axis, when
that bone is free, is usually very obtuse, or even obsolete. None
of the vertebrae are united together to form a sacrum. The lumbar
and caudal vertebrae are numerous and large, and, as their arches
are not connected by any articular processes (zygapophyses), they
are capable of a very free motion in all directions. The epiphyses
at the ends of the vertebral bodies are very distinct flattened disks,
not uniting until after the animal has attained its full dimensions. 1
There are largely developed chevron bones, the presence of which
indicates the distinction between the caudal and lumbar vertebrae.
The skull (Fig. 75) is modified in a very peculiar manner. The
brain-case is short, broad, and high, in fact almost spherical. The
supraoccipital bone rises upwards and forwards from the foramen
magnum, to meet the frontals at the vertex, thus completely
excluding the parietals from the upper region of the cranium. The
frontals are expanded laterally to form the roof of the orbits. The
anterior narial aperture opens upwards, and has in front of it a
more or less horizontally prolonged rostrum, formed of the maxillae,
premaxillse, vomer, and mesethmoid cartilage, extending forwards
to form the upper jaw or roof of the mouth.
There are no clavicles. The humerus is freely movable on the
scapula at the shoulder-joint, but beyond this the articulations of
the limb are impei'fect, the flattened ends of the bones coming in
contact Avith each other, with fibrous tissue interposed, allowing of
scarcely any motion. The radius and ulna are distinct, about
equally developed, and much flattened, as are also all the bones
of the manus. There are four, or more commonly five digits, and
the number of the phalanges of the second and third digits always
exceeds the normal number in mammals, sometimes very con-
siderably (hyperphalangism) ; they present the exceptional character
of having epiphyses at both ends. 2 The pelvis is represented by a
pair of small styliform bones placed longitudinally, suspended below
and at some distance from the vertebral column at the commence-
ment of the caudal region. These appear to represent the ischia,
as the crura of the corpora cavernosa are attached to them. In
some species, to the outer surface of these are fixed other small
bones or cartilages, the rudiments of the hind limb.
1 This is an important distinction from the Sirenia, but a character common
to nearly all other mammals. It is doubtful whether there is any foundation
for the statement that these epiphyses remain ununited for an exceptionally long
period in the Cetacea.
- A character repeated in some of the Seals.
GENERAL CHARACTERS
227
Teeth are generally present, but exceedingly variable in number.
In the exist i 11 g species they are of simple, uniform character, all
having conical or compressed crowns and single roots, and are never
preceded by milk-teeth. They are therefore homodont and
monophyodont. In one group, the Mystacocetes, the teeth are
absent (except in the foetal condition), and the palate is provided
with numerous transversely placed horny lamina? or "baleen."
The salivary glands are rudimentary or absent. The stomach is
multilocular, its structure being fully noticed under the genus
EjcO
Fig. 75. — A section of the skull of a young Dolphin (Globicephalus tnelas). x£. PMx, Pre-
maxilla ; Mx, maxilla ; ME, ossified portion of the mesethmoid ; an, anterior nares ; Na,
nasal ; IP, inter-parietal ; Ft, frontal ; Pa, parietal ; SO, supraoccipital ; ExO, exoccipital .
BO, basioccipital ; Sq, squamosal ; Per, periotic ; AS, alisphenoid ; PS, presphenoid ; Pt,
pterygoid; pa, posterior nares; PI, palatine; Vo, vomer; s, symphysis of mandible; id,
inferior dental canal ; cp, coronoid process of mandible ; cd, condyle ; a, angle ; sh, stylo-hyal ;
bh, basi-hyal ; th, thyro-hyal. (From Flower's Osteology of Mammalia.)
Phoccena. The intestinal canal is simple, and only in some species
provided with a small caecum. The liver is very little fissured, and
there is no gall-bladder. The vascular system is greatly complicated
by arterial and venous plexuses, or rctia mirabilia. The larynx is of
peculiar shape, the arytenoid cartilages and the epiglottis being-
much elongated, and together forming a tubular prolongation, which
projects into the posterior nares, and when embraced by the soft
palate produces a continuous passage between the nostrils and the
trachea, as in Ungulates, but in a more perfect manner. The
228 CETACEA
brain is large relatively to the size of the animal, very round in
form, and with its surface divided by sulci into very numerous and
complex convolutions. The kidneys are deeply lobulated. The
testes are abdominal. There are no vesiculae seminales, nor os
penis. The uterus is bicornuate, and the placenta nondeciduate
and diffuse. The mammae are two in number, and the nipples
placed in depressions on each side of the vulva. The principal
ducts of the gland are dilated during lactation into large reservoirs,
into which the milk collects, and from which it is injected by the
action of a compressor muscle into the mouth of the young animal,
by which means the process of sucking under Avater is greatly
facilitated and expedited.
The animals of the order Cetacea abound in all known seas,
and some species are inhabitants of the larger rivers of South
America and Asia. Their organisation necessitates passing their life
entirely in the water, as on land they are absolutely helpless.
They have, however, to rise very frecpiently to the surface for the
purpose of respiration ; and, in relation to the constant upward and
downward movement in the water thus necessitated, their principal
instrument of motion, the tail, is expanded horizontally, quite
unlike that of a fish, whose movements are mainly in straight-
forward or lateral directions. The position of the respiratory orifice
or nostril on the highest part of the head is very important for
this mode of life, since it is the only part of the body of which
the exposure above the surface is absolutely necessary. Of the
numerous erroneous ideas connected with natural history, few are
so wide spread and still so firmly believed, notwithstanding repeated
expositions of its falsity, as that the Cetacea spout out through
their blowholes water taken in at the mouth. The fact is, the
" spouting," or more properly " blowing," of the Whale is nothing-
more than the ordinary act of expiration, which, taking place at
longer intervals than in land animals, is performed with a greater
amount of emphasis. The moment the animal rises to the surface
it forcibly expels from its lungs the air taken in at the last inspira-
tion, which of course is highly charged with watery vapour in
consecpience of the natural respiratory changes. This, rapidly
condensing in the cold atmosphere in which the phenomenon is
generally observed, forms a column of steam or spray, which has
been erroneously taken for water. It also often happens, especially
when the surface of the ocean is agitated into waves, that the
animal commences its expiratory puff* before the orifice has quite
cleared the top of the water, some of which may thus be driven
upwards with the blast, tending to complete the illusion. In
hunting Whales the harpoon often jnerces the lungs or air passages
of the unfortunate victim, and then fountains of blood may be
forced high in the air through the blowholes, as commonly depicted
GENERAL CHARACTERS 229
in scenes of Antic adventure; but this is nothing more (allowance
being made for the Whale's peculiar mode of breathing) than what
always follows severe wounds of the respiratory organs of other
mammals.
All the Cetacea are predaccous, subsisting on living animal food
of some kind. One genus alone (Orca) eats other warm-blooded
animals, as Seals, and even members of its own order, both large
and small. Some feed on fish, others on small floating crustaceans,
pteropods, and medusae, while the principal staple of the food of
many is constituted by the various species of cephalopods, Loligo
and other Teuthidce, which must abound in certain seas in vast
numbers, as they form almost the entire support of some of the
largest members of the order. In size the Cetacea vary much, some
of the smaller Dolphins scarcely exceeding 4 feet in length, while
others are the most colossal of all animals. It is true that most
statements of their bulk found in general and even zoological
literature are greatly exaggerated, but even when reduced to
their actual dimensions (which will be stated under the respective
genera) some of the existing Whales exceed in size any animal
living either at present or in former times of which Ave have any
certain evidence. With some exceptions, the Cetacea generally are
timid inoffensive animals, active in their movements, and very
affectionate in their disposition towards one another, especially the
mother towards the young, of which there is usually but one, or
at most two at a time. They are generally gregarious, swimming
in herds or " schools '"' (so termed by the whalers) sometimes
amounting to many thousands in number ; though some species
have hitherto only been met with either singly or in pairs.
Although by their mode of life so far removed from close ob-
servation that it is impossible to become as familiar with them in
their natural condition as with many other animals, Whales are in
many respects the most interesting and wonderful of all creatures ;
and there is much in their structure and habits well worthy of
study, much that is difficult to understand, and much that leads to
great generalisations and throws light upon far-reaching philosophical
speculations. One of the first lessons which a study of these
animals affords is that, in the endeavour to discover what a creature
really is, from what others it is descended, and to what it is related,
the general outward appearance affords little clue, and we must go
deep below the surface to find out the essential characteristics of its
nature. There was once, and may be still in many places, a
common idea that a Whale is a fish. To realise the fallacy of this
notion we have only to consider what a fish really is, what under
all the diversities of form, size, and colour known among fishes
there is common to them all, and we see that in everything which
characterises a true fish and separates it from other classes, as
CETACEA
reptiles, birds, and mammals, the Whale resembles the last-named
and differs from the fish. It is as essentially a mammal as a Cow
or a Horse, and simply resembles a fish externally because it is
adapted to inhabit the same element ; but it is no more on that
account a fish than is a bat, because adapted to pass a great part of
its existence on the wing in the air, nearly related to a bird. The
whole structure of a whale is a most instructive instance of a type
of organisation which is common to and characteristic of the class
Mammalia, but specially modified or adapted to a peculiar mode of
life. We see in every part the result of two great principles acting
and reacting upon each other — on the one hand, adherence to type,
or rather to fundamental inherited structural conditions, and, on
the other, adaptation to the peculiar circumstances under which it
lives, and to which in all probability it has become gradually more
and more fitted. The external fish-like form is perfectly suited for
swimming through the water ; the tail, however, is not placed
vertically as in fishes, but horizontally, a position which accords
better with the constant necessity for rising to the surface for the
purpose of breathing. The hairy covering characteristic of all
mammals, which if present might interfere with rapidity of move-
ment through the Avater, is reduced to the merest rudiments — a
few short bristles about the chin or upper lip — which are often
only present in very young animals ; and the function of keeping
the body warm is supplied by the "blubber." The fore-limbs,
though functionally reduced to mere paddles, with no power of
motion except at the shoulder-joint, have beneath their smooth and
continuous external covering all the bones, joints, and even most of
the muscles, nerves, and arteries of the human arm and hand ; and
the rudiments of hind legs found buried deep in the interior of the
animal apparently subserve no useful purpose, but point an in-
structive lesson to those who are able to read it.
As before said, the Cetacea form a perfectly well-defined group,
sharply separated from all other mammals, and with no outlying or
doubtful forms at present known. Among the existing members
of the order, there are two very distinct types, the Toothed Whales
or Odontoceti and the Baleen Whales or Mystacoceti, which present
as many marked distinguishing structural characters as are found
between many other divisions of the Mammalia which are reckoned
as orders. The extinct Zeuglodon, so far as its characters are known,
does not fall into either of these groups, but is in some respects an
annectant form, and therefore must be placed, provisionally at least,
in a third group by itself.
The Mystacocetes appear at first sight to be the most specialised
and aberrant of the existing Cetacea, as indicated by the absence of
teeth, the presence of baleen, and the form and size of the mouth ;
but, as we see in other groups, dental characters, and all such as
GENERAL CHARACTERS 231
relate to the prehension of food generally, are essentially adaptive
and consequently plastic or prone to variation, and hence can-
not well be relied upon as tests of affinity. In another character,
also adaptive, the laxity of the connection of the ribs with the
vertebral column and with the sternum, and the reduction of that
bone in size, allowing great freedom of expansion of the thoracic
cavity for prolonged immersion beneath the water, the Mystacocetes
have passed beyond the Odontocetes in specialisation. On the other
hand, the greater symmetry of the skull, the more anterior position
of the external nostrils and their double external orifice, the form
of the nasal bones, the presence of a distinctly developed olfactory
organ, the mode of attachment of the periotic bone to the cranium,
the presence of a caecum and the regular arrangement of the
alimentary canal, the more normal characters of the manus and the
better development of the muscles attached to it, and the presence,
in many species at least, of parts representing not only the bones
but also the ligaments and muscles of a hind limb, 1 all show less
deviation from the ordinary mammalian type than is presented by
the Odontocetes. Taking all these characters into consideration, it
does not appear reasonable to suppose that either type has been
derived from the other, at all events in the form in which we see
it now, but rather that they are parallel groups, both modified in
different fashions from common ancestors.
Among the Mystacocetes, in the especially distinguishing
characters of the division, the Rorquals are less specialised than the
Right Whales, which in the greater size of the head, the length and
compression of the rostrum, the development of the baleen, and
shortness of the cervical region, are exaggerated forms of the type,
and yet they retain more fully some primitive characters, as the
better development of the hind limb, the pentadactylous manus,
and the absence of a dorsal fin. Both types are found distinct in
a fossil state at least as far back as the early Pliocene age, but
generally represented by smaller species than those now existing.
Some of the Pliocene Rorquals (Cetotherium) were, in the elongated
flattened form of the nasal bones, the greater distance between the
occipital and frontal bone at the top of the head, and the greater
length of the cervical vertebra?, more generalised than those now
existing. In the shape of the mandible also, Van Beneden, to
whose researches we are much indebted for a knowledge of these
forms, discerns some approximation to the Odontocetes.
Among the last-named group there are several distinct types, of
which that represented by Platanista, although in some respects
singularly modified, has been considered to present on the whole
approximations towards the more normal and general type of
1 These have been described in detail by Professor Struthers in the Journal of
Anatomy and Physiology, 1881.
232 CETACEA
mammalian structure. It is therefore interesting to find an
apparently allied form well represented among the earliest fossil
remains of Cetaceans in Europe. Almost all the other members of
the suborder range themselves under the two principal heads of
Ziphioids (or Physeteroids) and Delphinoids. The former is an
ancient and once abounding t} r pe, of which the Sperm Whale
(Physeter) is a highly specialised form. Among the latter, Globi-
cephalus is a modified form as regards the structure of its anterior
extremity, and Monodon as regards its dentition, while Delphinus,
Avith the various allied genera, may be regarded as the domi-
nating type of Cetaceans at the present day, abundant in slightly
differentiated species and also in individuals. They are in this
respect to the rest of the order much as the hollow -horned
Ruminants are to the other Ungulates.
The earliest Cetaceans of whose organisation we have anything
like complete evidence are the Zeuglodonts of the Eocene period, 1
which approach in the structure of the skull and teeth to a much more
generalised mammalian type than either of the existing suborders.
The smallness of the cerebral cavity compared with the jaws and the
rest of the skull they share Avith the primitive forms of many other
types. The forward position of the narial aperture and the length
and flatness of the nasal bones, Avhich distinguish them from all
existing forms, Ave must also suppose to be a character at one time
common to all Cetaceans, though noAV retained (but to a less degree)
only by the Mystacocetes. Even Squalodon, Avhich in its heterodont
dentition so much resembles Zeuglodon as to have been placed by
some zoologists in the same genus, entirely differs from it, and
conforms Avith the ordinary Dolphins in its essential cranial
characters.
The origin of the Cetacea is at present invoked in much ob-
scurity. They present no signs of closer affinity to any of the
loAver classes of A r ertebrates than do many other members of their
own class. Indeed in all that essentially distinguishes a mammal
from the oviparous Arertebrates, Avhether in the osseous, nervous,
reproductive, or any other system, they are as truly mammalian as
any other group. Any supposed marks of inferiority, as absence
of limb structure, of hairy covering, of lachrymal apparatus, etc., are
obviously modifications (or degradations, as they may be termed)
in adaptation to their special mode of life. The characters of the
teeth of Zeuglodon and other extinct forms, and also of the foetal
Mystacocetes, clearly indicate that they have been derived from
mammals in AAdiich the heterodont type of dentition was fully
1 The ankylosed mass of cervical vertebrae, on which the genus Palceocetus was*
established, was regarded by its describer as having probably come from the
Kimeridge Clay, but the mineral condition of the specimen points to the Red
Crag as the place of origin.
GENERAL CHARACTERS 233
established. The steps by which a land mammal may have been
modified into a purely aquatic one are indicated by the stages
which still survive among the Carnivora in the Otariidas and in
the true .Seals. A further change in the same direction would pro-
duce an animal somewhat resembling a Dolphin ; and it has been
thought that this may have been the route by which the Cetacean
form has been developed. There are, however, great difficulties in
the way of this view. Thus if the hind limbs had ever been
developed into the very efficient acpiatic propelling organs they
present in the Seals, it is not easy to imagine how they could have
become completely atrophied and their function transferred to the
tail. So that from this point of view it is more likely that Whales
were derived from animals with long tails, which were used in
swimming, eventually with such effect that the hind limbs became
no longer necessary. The powerful tail, with its lateral cutaneous
flanges, of an American species of Otter (Lutra brasiliensis) may give
an idea of this member in the primitive Cetaceans. But the struc-
ture of the Cetacea is, in so many essential characters, so unlike
that of the Carnivora that the probabilities are against these orders
being nearly related. Even in the skull of the Zeugloclon, which
has been cited as presenting a great resemblance to that of a Seal,
quite as many likenesses may be traced to one of the primitive Pig-
like Ungulates (except in the purely adaptive character of the form
of the teeth), while the elongated larynx, 1 complex stomach, simple
liver, reproductive organs both male and female, and foetal mem-
branes of the existing Cetacea are far more like those of that group
than of the Carnivora. Indeed it appears probable that the old
popular idea which affixed the name of " Sea-Hog " 2 to the Porpoise
contains a larger element of truth than the speculations of many
accomplished zoologists of modern times. The fact that Platanista,
which, as mentioned above, appears to retain more of the primitive
characteristics of the group than any other existing form, and also
the somewhat related Inia from South America, are both at the
present day exclusively fluviatile, may point to the fresh-water origin
of the whole group, in which case their otherwise rather inexplic-
able absence from the seas of the Cretaceous period would be
accounted for.
On the other hand, it should be observed that the teeth of the
Zeuglodonts approximate more to a carnivorous than to an ungulate
type. It is scarcely necessary to allude to the hypothesis started
by some Continental writers to the effect that the Whales are the
most primitive type of mammals with which we are acquainted,
1 There is much resemblance in the larynx of the Hippopotamus, but none
in that of the Seal, to the same organ in the Cetacea.
2 German Meerscliwfin, whence the French Marsouin. "Porpoise" is said
to be derived from " Porc-2>oisson."
234 CETACEA
and that they are the descendants of the Mesozoic reptilian order
Ichthyopterygia, from which their hyperphalangism is a direct
inheritance. The Ichthyopterygia have been shown, on very strong
evidence, to have been derived from land reptiles, and to have
gradually acquired their hyperphalangism as an adaptive character
suitable to their peculiar mode of life, and there can be but little
doubt that a similar adaptation has taken place in the case of the
"Whales.
Suborder Mystacoceti,
the Bal.exoidea, Whalebone, or True TVliales. 1
Family Bal.enid.e.
Teeth never functionally developed, but always disappearing
before the close of intra-uterine life. Palate provided with plates
of baleen or "whalebone." Skull symmetrical. Nasal bones form-
ing a roof to the anterior nasal passages, which are directed upwards
and forwards. Maxilla produced in front of, but not over, the
orbital process of the frontal. Lachrymal bones small and distinct
from the jugal. Tympanic bone involuted (Fig. 76), and ankylosed
with the periotic, which is attached to the base of the cranium by
two strong diverging processes. Olfactory organ distinctly de-
veloped. Rami of mandible arched outwards, their anterior ends
meeting at an angle, and connected by fibrous tissue without any
true symphysis. All the ribs at their upper extremities articulating
only with the transverse processes of the vertebras ; their capitular
processes, when present, not articulating directly with the bodies of
the vertebra?. Sternum composed of a single piece, and articulating
only with a single pair of ribs. No ossified sternal ribs. External
openings of nostrils distinct from each other, longitudinal. A short
conical caecum.
These animals have, Avhen in the fcetal state, numerous minute
calcified teeth lying in the dental groove of both upper and lower
jaws. They are best developed about the middle of fcetal life, after
which period they are absorbed, and no trace of them remains at the
time of birth.' 2 The baleen or Avhalebone does not make its appear-
ance until after birth. It consists of a series of flattened horny
plates, between three and four hundred in number, on each side of
1 Icel. hvalr ; Dan. and Swed. lived; Anglo-Saxon hwcel ; Germ, wal,
walfisch. The meaning apparently is "roller," the word being closely allied to
" wheel " (Skeat).
2 These were discovered in the Greenland Whale by Geoffroy St. Hilaire,
whose observations were confirmed and extended to other genera by Eschrieht.
They have been very fully described in Balcenoptera rostrata by Julin (Archivs
dc Biologic, i. 1S80).
BAL.-ENID.K 235
the palate, with a bare interval along the middle line. These plates
are placed transversely to the long axis of the palate, with very short
i nt rivals between them. Each plate or blade is somewhat triangular
in form, with the base attached to the palate and the apex hanging
down wauls. The outer edge of the blade is hard and smooth ; but
the inner edge and apex fray out into long bristly fibres, so that the
roof of the Whale's mouth looks as if covered with hair, as described
by Aristotle. At the inner edge of each principal blade are two
or three much smaller or subsidiary blades. The principal blades
are longest near the middle of the series, and gradually diminish
towards the front and back of the mouth. The horny plates grow
from a dense fibrous and highly vascular matrix, covering the
palatal surface of the maxilla?, and sending out lamellar processes,
one of which penetrates the base of each blade. Moreover, the
free edge of these processes is covered with very long vascular
thread-like papilla?, one of which forms the central axis of each of
the hair-like epidermic fibres of which the blade is mainly composed.
A transverse section of fresh whalebone shows that it is made up of
numbers of these soft vascular papilla?, circular in outline, each
surrounded by concentrically arranged epidermic cells, and the
whole bound together by other epidermic cells, that constitute the
smooth cortical (so-called " enamel ") surface of the blade, which,
disintegrating at the free edge, allows the individual fibres to
become loose and assume the hairdike appearance before spoken of.
These fibres differ from hairs in not being formed in depressed
follicles in the enderon, but rather resemble the fibres composing the
horn of the Rhinoceros. The whalebone in fact consists of nothing-
more than modified papilla? of the buccal mucous membrane, with
an excessive and cornified epithelial development. The blades are
supported and bound together for a certain distance from their
base by a mass of less hardened epithelium, secreted by the surface
of the palatal membrane or matrix of the whalebone in the intervals
of the lamellar processes. This is the " intermediate substance " of
Hunter, the " gum " of the whalers. Baleen varies much in colour
in different species. In some it is almost jet black, in others slate-
colour, horn -colour, yellow, or even creamy- white. In some the
blades are variegated with longitudinal strips of different hues.
Baleen differs also greatly in other respects, being short, thick,
coarse, and stiff in some, and greatly elongated and highly elastic
in those species in which it has attained its fullest development.
Its function is to strain the water from the small marine molluscs,
crustaceans, or fish upon which the Whales subsist. In feeding the
immense mouth is filled with water containing shoals of these small
creatures, and then, on the Whale closing the jaws and raising the
tongue, so as to diminish the cavity of the mouth, the water streams
out through the narrow intervals between the hairy fringe of the
'■36
CETACEA
whalebone blades, and escapes through the lips, leaving the livino-
prey to be swallowed. 1
Our knowledge of the different structural modifications attained
by members of this important group of mammals, though largely
increased of late years, is still imperfect. Formerly they were all
divided into Right Whales (Balcena) and Rorquals or Fin-Whales
(Balcenoptera), the latter distinguished by their smaller heads,
elongated and slender form, free cervical vertebra?, tetradactylous
maims, and the presence of very conspicuous longitudinal furrows or
folds in the skin of the throat and chest, and of a small adipose
dorsal fin. Recent discoveries have, however, brought to light
several forms holding a somewhat intermediate position, and pre-
senting combinations of characters not found in either of the longer
known sections. According to our present knowledge the group is
naturally divided into five very distinct genera, of which the leading-
characters are given below.
Balcena. 2 — Skin of throat smooth, not furrowed. No dorsal fin.
Cervical vertebra? united into a single mass. Pectoral limb short,
broad, and pentaclactylous. Head very large. Baleen very long
and narrow, highly elastic, and black. Scapula high, with a distinct
coracoid and acromion process. Tympanic (Fig. 78) deep and angular,
its inflation comparatively slight, and the involuted portion not fig-
shaped, and frequently without a well-marked depression at the
anterior extremity of the superior border of the inner surface for
the Eustachian canal.
Fig. 76.— Greenland or Arctic Right Whale (Balcena mysticetv •).
The Greenland, or more properly Arctic, Right Whale (Balcena
mysticetus) attains, when full grown, a length of from 45 to 50
feet. Its usual vertebral formula is C 7, D 12, L 14, C 22.
The external form is shown in Fig. 76 from a careful drawing by
1 For the structure of whalebone see Hunter, "Observations on the Structure
and Economy of Whales," Phil. Trans. 1787 ; Eschricht and Reinhardt, On the
Greenland Right Whale, English translation by the Ray Society, 1866, pp. 67-78 ;
and Sir W. Turner, in Trans. Roy. Soc. Edin. 1870.
2 Linn. Syst. Nat. 12th ed. vol. i. p. 105 (1766).
BAL.E.Xin.E 237
Mr. Robert Gray. In this species all the peculiarities which
distinguish the head and mouth of the Whales from those of other
mammals have attained their greatest development. The head is
of enormous size, exceeding one-third of the whole length of the
creature. The cavity of the mouth is actually larger than that of
the body, thorax and abdomen together. The upper jaw is very
narrow, but greatly arched from before backwards, to increase the
height of the cavity and allow for the great length of the baleen
blades ; the rami of the mandible are widely separated posteriorly,
and have a still further outward sweep before they meet at
the symphysis in front, giving the floor of the mouth the shape
of an immense spoon. The baleen blades attain the number
of 380 or more on each side, those in the middle of the series
having a length of 10 or sometimes 12 feet. They are black in
colour, fine and highly elastic in texture, and fray out at the inner
edge and ends into long, delicate, soft, almost silky, but very tough,
hairs. The remarkable development of the mouth and the structures
in connection with it, which distinguishes the Eight Whale among
all its allies, is entirely in relation to the nature of its food. It
is by this apparatus that the animal is enabled to avail itself of
the minute but highly nutritious crustaceans and pteropods which
swarm in immense shoals in the seas it frequents. The large mouth
enables it to take in at one time a sufficient quantity of water filled
with these small organisms, and the length and delicate structure
of the baleen provide an efficient strainer or hair-sieve by which the
water can be drained off. If the baleen were rigid, and only as
long as is the aperture between the upper and lower jaws when the
mouth is shut, a space would be left beneath it Avhen the jaws were
separated, through which the water and the minute particles of food
would escape together. But instead of this the long, slender,
brushdike, elastic ends of the whalebone blades fold back when
the mouth is closed, the front ones passing below the hinder
ones in a channel lying between the tongue and the loAver jaw.
When the mouth is opened, their elasticity causes them to
straighten out like a bow unbent, so that at whatever distance
the jaws are separated the strainer remains in perfect action,
filling the whole of the interval. The mechanical perfection of
the arrangement is completed by the great development of the
lower lip, which rises stiffly above the jaw-bone and prevents the
long, slender, flexible ends of the baleen from being carried
outwards by the rush of water from the mouth, when its cavity
is being diminished by the closure of the jaws and raising of the
tongue.
If, as appears highly probable, the " bowhead " of the Okhotsk
Sea and Behring Strait belongs to this species, its range is circum-
polar. Though found in the seas on both sides of Greenland, and
238 CETACEA
passing freely from one to the other, it is never seen so far south
as Cape Farewell ; but on the Labrador coast, where a cold stream
sets down from the north, its range is somewhat farther. In the
Behring Sea, according to Scammon, "it is seldom seen south of
the fifty-fifth parallel, which is about the farthest southern extent
of the winter ice, Avhile on the Sea of Okhotsk its southern limit is
about the latitude of 54°." As has been abundantly shown by
Eschricht and Bernhardt in the case of the Greenland seas, " every-
thing tends to prove," Scammon says, " that the Balcena mysticetus
is truly an ' ice Avhale,' for among the scattered floes, or about the
borders of the ice-fields or barriers, is its home and feeding-ground.
It is true that these animals are pursued in the open water during
the summer months ; but in no instance have we learned of their
being captured south of where winter ice-fields are occasionally met
with." The occurrence of this species, therefore, on the British or
any European coast is exceedingly unlikely, as when alive and in
health the southern limit of its range in the North Sea has been
ascertained to be from the east coast of Greenland at 64° N. lat.
along the north of Iceland towards Spitzbergen, and a glance at a
physical chart will show that there are no currents setting south-
wards which could bear a disabled animal or a floating carcase to
British shores. To this a priori improbability may be added the
fact that no authentic instance has been recorded of the capture or
stranding of this species upon any European coast ; for the cases
in which it has been reported as seen in British waters may be ex-
plained by the supposition of one of the other species of the genus
being mistaken for it. Still, as two other essentially Arctic
Cetaceans, the Narwhal and the Beluga, have in a few undoubted
instances found their way to British shores, it would be rash
absolutely to deny the possibility of the Greenland Bight Whale
doino- the same.
Fig. 77.— Southern Right Whale (Balcena australis).
The southern Bight Whale (B. australis, Fig. 77) resembles the
last in the absence of dorsal fin and of longitudinal furrows in the
skin of the throat and chest, but differs in that it possesses a smaller
head in proportion to its body, shorter baleen, a different shaped
contour of the upper margin of the lower lip, and a greater number
BAL.KXID.K 239
(fifteen) of ribs and dorsal vertebrae. This form inhabits the tem-
perate seas of both northern and southern hemispheres, and is
divided into several so-called species, according to their geographical
distribution : — 1!. biscayensis of the North Atlantic, B. japonica of
the North Pacific, B. a it. Oralis of the South Atlantic, and B. anti-
podarum and J!, novce-zealandice of the South Pacific. The differential
characters by which they have been separated, external as well as
anatomical, are, however, slight and subject to individual variation ;
and the number of specimens available for comparison in museums
is not yet sufficient to afford the necessary data to determine
whether these characters can be regarded as specific or not.
The most interesting of these is the Atlantic Right Whale,
which was formerly abundant in the North Atlantic, but is
now so scarce as to appear verging on extinction. This was
the Whale the pursuit of which gave occupation to a numerous
population on the shores of the Basque provinces of France and
Spain in the Middle Ages. From the tenth to the sixteenth centuries
Bayonne, Biarritz, St. Jean de Luz, and San Sebastian, as well as
numerous other towns on the north coast of Spain, were the centres
of an active AVhale "fishery," which supplied Europe with oil and
whalebone. In later times these Whales were pursued as far as the
coast of Newfoundland. They were, however, already getting scarce
when the voyages undertaken towards the close of the sixteenth
century for the discovery of the north-eastern route to China and
the East Indies opened out the seas around Spitzbergen ; then for
the first time the existence of the Greenland Whale became known,
and henceforth the energies of the European whale- fishers were
concentrated upon that animal. It is a singular fact that the
existence of the Atlantic Right Whale was quite overlooked by
naturalists till lately, all accounts referring to it being attributed to
the Greenland Whale, supposed once to have had a wider distribu-
tion than now, and to have been driven by the persecution of man
to its present circumpolar haunts. To the two Danish cetologists
Eschricht and Reinhardt is due the credit of having proved its
existence as a distinct species, from a careful collation of numerous
historical notices of its structure, distribution, and habits ; and their
restoration of the animal, founded upon these documents, has been
abundantly confirmed by the capture of various specimens in recent
times, showing that it still lingers in some of the localities where it
formerly was so abundant. The only known instances of its
occurrence on the coasts of Europe in modern times are in the
harbour of San Sebastian in January 1854, in the Gulf of Taranto,
in the Mediterranean, in February 1877, and on the Spanish coast
between Guetaria and Zarauz (Guipuzcoa) in February 1878. The
skeletons of these three whales are preserved in the museums of
Copenhagen, Naples, and San Sebastian respectively. On the coast
240
GET ACE A
of the United States several Whales of this species have been taken
within the last few years. In the North Pacific a very similar if
not identical species is regularly hunted by the Japanese, who tow
the carcases ashore for the purposes of flensing and extracting
the whalebone. In the tropical seas, however, according to Captain
Maury's whale charts, Right Whales are never or rarely seen ; but
the southern temperate ocean, especially the neighbourhood of the
Cape of Good Hope, Kerguelen's Island, Australia, and New Zea-
land, is inhabited by "Black Whales," once abundant, but now
nearly exterminated through the wanton destruction of the females
as they visit the bays and inlets round the coast, their constant
habit in the breeding time. The range of these Whales southward
has not been accurately determined ; but no species corresponding
with the Arctic Eight Whale has as yet been met with in the
Antarctic icy seas.
Fig. 7S. — The right tympanic bone of an immature individual of the Greenland Whale
(Bakena mysticetus), from the inner (^4) and outer (-B) aspects. J natural size. (From the
Froc. Zool. Soc.)
Remains of Right Whales are of not uncommon occurrence in the
Pliocene Crag deposits of England and Belgium. The tympanies
of B. affinis from these deposits appear to indicate a species closely
allied to B. mysticetus, in which this bone is long and angulated
anteriorly (Fig. 78) ; while the tympanies from the same deposits
described as B. primigenia are shorter and more rounded at the
anteroinferior angle, thus resembling those of B. australis. A
smaller species, having an estimated length of about 20 feet, has
been described as Balcenula balcenopsis, the generic distinction being-
made on account of the free condition of the atlas and seventh
cervical vertebras ; but it seems scarcely advisable to regard such a
feature as indicating more than a less specialised species. Balcena
( Balcenotus) insignis is a whale of somewhat larger dimensions, in
which the atlas is generally, and the seventh cervical vertebra
BALAZNIDsE
241
always, free, while in young individuals the axis vertebra may
likewise be separate.
Neobalcema. 1 — Head about one-fourth the total length. Skin of
the throat not plicated. A small falcate dorsal fin. Vertebra?,
C 7, D 17, L 3, C 1G = 43 The cervical vertebra? are united. The
manus small, narrow, and tetradactylous, wanting the pollex. The
ribs remarkably expanded and flattened. The scapula very low
and broad, with completely developed acromion and coracoid pro-
cesses. Tympanic approximating to that of Balcena, but with certain
very characteristic peculiarities of shape. Baleen very long, slender,
elastic, and white. A single species, at present very rare, N. mar-
ginata, from the Australian and New Zealand seas is the smallest
of the Whalebone "Whales, being not more than 20 feet in length.
Ehachianectes. 2 — This combines the small head, elongated form,
and narrow pectoral fin of Balcenoptera with the smooth skin of the
throat and absence of the dorsal fin of Balcena. The baleen is the
shortest and coarsest of any of the group. Its osteology is im-
perfectly known. One species, B. glaucus, the Gray Whale of the
North Pacific.
Megaptera. 3 — Head of moderate size. Baleen plates short and
broad. Vertebra?, C 7, D 14, L 11, C 21=5 3. Cervical vertebra?
free. Scapula with acromion and coracoid process absent or rudi-
mentary. Skin of throat plicated. Dorsal fin low. Pectoral limb
tetradactylous, very long and narrow, attaining about one-fourth of
the length of the entire animal, the metacarpus and phalanges
being greatly developed, and the latter very numerous. Tympanic
still more inflated than in Balcenoptera, with the involuted portion
more distinctly pyriform, the Eustachian part of the aperture well
defined, and two well-marked longitudinal ridges on the lower
surface of adult specimens.
The Whale commonly called " Humpback " (Megaptera hoops) by
whalers, perhaps on account of the low hump- like form of the
dorsal fin, is very distinctly characterised from all others of the
group, especially by the immense length of the pectoral fins or
flippers, which are indented or scalloped along their margins, and
are, except at their base, of a white colour, nearly all the rest of
the body being black. The baleen plates are of a deep black
colour. Though common in the North Atlantic between Norway
and Greenland, this Whale does not frequently appear on the coasts
of the British Isles. One came ashore at Newcastle in 1839 ;
another, a young one, was taken in the estuary of the Dee in 1863,
and its skeleton is preserved in the Liverpool museum ; and a
nearly full-grown animal was captured in the mouth of the Tay in
1 Gray, Sujypl. Cat. Seals and Whales in Brit. Mus. p. 39 (1871).
2 Cope, Proc. Ac. Nat. Sci. Philad. 1869, p. 15.
3 Gray, Zoology of Erebus and Terror, p. 16 (1846).
16
!42
CETACEA
the winter of 1883-S4. 1 The usual length of the adult ranges from
45 to 50 feet, the female being larger than the male. Whales of
Fig. 79. — Humpbacked Whale (Megaptera boops).
the genus Megaptera are found in the South Atlantic and in
both the North and the South Pacific. They
resemble those of British seas so closely that it
is doubtful whether the differences Avhich have
been observed, and upon which several species
have been founded, may not be individual peculi-
arities ; but zoologists have not yet had the
opportunity of examining and comparing such
a series of specimens of different ages and sexes
from different localities as would be necessary
to determine these points satisfactorily.
Tympanic bones of Megaptera occur in the
English and Belgian Oags, although somewhat
less commonly than those of Balcma and Balcem-
optera ; they have been described under the
names of Megapteropsis and Burtinopsis.
Balwnoptera. 2 — Head small and flat, and
pointed in front. Body long and slender. Skin
of throat plicated. A small falcate dorsal fin.
Baleen short and coarse. Cervical vertebra? free.
Scapula low and broad, with a large acromion
and coracoid process. Pectoral limb tetradacty-
H lous, small, narrow, and pointed. Tympanic
I. (Fig. 81) long, much inflated, and rounded, with
™ the involuted portion thickened and pyriform,
& and the notch for the Eustachian canal sharply
defined ; inner surface flattened, without the
vertical groove found in Megaptera.
The Rorquals, Fin-Whales, Fin-backs, Fin-
ners, or Razor-backs, as they are variously called,
K)
O
o
1 See J. Struthers, ' ' On the Anatomy of Megaptera
longimana," Journ. Anatomy and Physiology, 1887-89.
2 Lacepede, "Table des Ordres," Hist. Nat. ties Cetacis,
p. xxxvi. (1804).
BALsENID.E
243
have the plicated skin of the throat like that of Mfi/nptcni, the
furrows being more numerous and close set ; but the pectoral
fin is comparatively
small, the dorsal fin
distinct and falcate,
and the tail very
much compressed
before it expands
into the "flukes."
The Rorquals are
perhaps the most
abundant and widely
distributed of all the
whales, being found
in some of their
modifications in all
seas, except the ex-
treme Arctic, and
probably Antarctic
regions. Owing to
the small quantity
and inferior quality
of their whalebone,
the comparatively
limited amount of
blubber, and their
great activity and
the difficulty of cap-
turing them by the
old methods, these
"Whales were not
until recently an object of pursuit by whale-fishers; but, since the in-
troduction of steam-vessels, and especially of explosive harpoons fired
from guns in the place of those hurled by the human hand, a regular
fishery has been established on the coast of Finmark. There are four
distinct species of this genus in British seas. (1) Balcenoptera sib-
baldi, the " Blue Whale," the largest of all known animals, attains a
length of 80 or even sometimes 85 feet. Its colour is dark bluish
gray, with small whitish spots on the breast ; the baleen is black ;
the flippers are larger proportionally than in other Rorquals,
measuring one-seventh of the total length of the body; and the dorsal
fin is small and placed very far back. This Whale has usually 64
vertebrae, of which 1 6 bear ribs. Like the others of the genus, this
species seems to pass the winter in the open seas, and approaches the
coast of Norway at the end of April or beginning of May. At this
time its sole food is a small crustacean (Euplumsia inermis) which
Fig. SI. — The right tympanic of Bakenoirtera nmsculus from
the inner (A) and outer (B) aspects. J natural size. (From the
Proc. Zool. Soc.)
244 CETACEA
swarms in the fjords. Several specimens have been taken on the
British coasts, two fine skeletons from the Firth of Forth being pre-
served in the Edinburgh museums. (2) Balcenoptera musculus, the
Common Eorqual, has a length of 65 to 70 feet, is of a grayish slate
colour above and white underneath, and the baleen is slate colour
variegated •with yellow or brown. It has usually 62 vertebrae,
of which 15 bear ribs. This is the commonest of all the large
Whales on the British coasts, scarcely a winter passing with-
out the body of one being somewhere washed ashore, usually
after stormy weather, and more frequently on the south coast,
as this species has a more southern range than the last, and
frequently enters the Mediterranean. It feeds largely on fish,
and is frequently seen feasting among shoals of herring. (3)
Bala'noptera borealis, often called Rudolphi's "Whale from its first
describer, is a smaller species, scarcely attaining a length of 50 feet.
It is bluish -black above, with oblong, light-coloured spots, whilst
the under parts are more or less white ; the whole of the tail and
both sides of the flippers are black ; the baleen is black, and the
bristly ends fine, curling, and white ; the flippers are very small,
measuring one-eleventh of the total length of the body. There are
56 vertebra?, with 14 pairs of ribs. This species, according to
Collett, feeds chiefly on minute crustaceans, mainly Calanus finmar-
chicus and Euphausia inermis, and not on fish. Until lately it was
considered the rarest of the Whales of European seas, and was only
known to science from a few individuals stranded on the coasts of
northern Europe at long intervals, the skeletons of which have been
preserved in museums. The most southern point at which it has
been met with hitherto is Biarritz in France. Since the establish-
ment of the whaling station near the North Cape it has been shown
to be a regular summer visitor, and in 1885, 771 individuals were
captured on the coast of Finmark. (4) Balcenoptera rostrafa, the
lesser Fin- Whale or Rorqual, is the smallest species found in the
northern seas, rarely exceeding 30 feet in length. Its colour is
grayish-black above, whilst the under side is white, including the
whole of the lower side of the tail ; the inner side of the flippers
is white ; and there is a broad white band across the outer side,
which is a very characteristic mark of the species ; the baleen is
yellowish-white. The dorsal fin in this and the last species is
comparatively high, and placed far forwards on the body. This
Whale has usually 48 vertebra?, 1 1 of which bear ribs. It is common
in summer in the fjords of Norway, and is often seen around the
British Isles. It has been taken, though rarely, in the Mediterranean ;
and ranges as far north as Davis's Straits.
Rorquals are met with in almost all seas throughout the world,
but further and more accurate observations are required before
their specific characters and geographical distribution can be made
BALAZNIDAZ 245
out. Nearly all the individuals hitherto examined with any care,
whether from the North Pacific, the Australian seas, or the Indian
Ocean, come very near in structure to one or the other of the
Atlantic forms described above, so much so that some zoologists
have been induced to believe that there are but four species, each
of which has a wide, almost cosmopolitan range, while others have
described and named almost every individual specimen captured as
belonging to a different species. 1
Tympanies, vertebra?, and other bones of Rorquals are among
the commonest cetacean remains found in the Pliocene Crags of
England and Belgium. Several species, varying in dimensions, are
known from these deposits, B. definite (sibbaldina) being apparently
nearly related to the existing B. sibbaldi. A caudal vertebra from
the Upper Eocene of Hampshire has been referred to Bakmoptcra, but
does not afford sufficient evidence to prove the existence of the
genus at that date.
Extinct Genera. — The extinct genus Cctotherium of the European
Pliocene may be taken to include a number of fossil Whalebone
"Whales allied to the Balamopterine group, several of which have
been described under other names, such as Plesiocetus, Heterocetus,
and Amphicetus. They are readily characterised by the form of
the tympanic bone, which is much narrower in front than behind,
the roughened inferior surface being in the shape of an isosceles
triangle, and the notch for the Eustachian canal being smaller, and
descending nearer to the inferior border of the inner wall than in
Balcmoptera. The skull is longer than the latter, with a greater
interval between the occiput and the frontal, and with longer and
more flattened nasals. The relative thickness of the cervical
vertebra? is also greater. In the typical forms (e.g. C. brialmonti
and C. dubiuni) the mandibular condyle is simple ; but in C.
(Heterocetus) brevifrons it is furnished with a projecting posterior
talon, as in the Sperm Whale.
IB ipetocetus is known by a comparatively small species from the
Belgian and English Crags, characterised by the extreme inflation
of the egg-shaped tympanic bone, which approximates to that of
Megaptera, but has the greater part of the cavity filled by bone.
There is a talon to the condyle of the mandible.
Baheocetus, as already mentioned (p. 232), is founded upon the
ankylosed cervical vertebra? of a small Whale originally considered as
having been derived from the Kimeridge Clay, but which doubtless
came from the Suffolk Crag ; if it belongs to the Balcenidce it indi-
cates a Eight Whale.
1 See P. J. Van Beneden, "Histoire Naturelles des Balenopteres, " Mem. Acad.
Belgique, xli. 1887.
246 CETACEA
Suborder Arcileoceti.
Family Zeuglodontid^e.
This group is formed to include certain extinct Cetacean-like
animals at present only known by more or less fragmentary por-
tions of their skeleton and teeth, and whose position and affinities
are, therefore, still subject to doubt. 1
In the anterior part of both jaws the teeth are simple, conical,
or slightly compressed, and sharp pointed. The first three in the
upper jaw are distinctly implanted in the premaxillary bone, and
so may be reckoned as incisors. The tooth which succeeds, or the
canine, is also simple and conical, but it does not exceed the others
in size. This is followed by five teeth having two distinct roots
and compressed pointed crowns, with denticulated cutting-edges.
The dentition is therefore i -§ , c \, p and in -§- = 36, resembling that
of some Seals. 2 General form of the skull elongated and much
depressed. Brain-cavity very small, and the skull between it and
the orbits elongated and narrow. Temporal fossae very large. A
strong sagittal crest. Rostrum long and narrow, differing from
that of other Cetaceans in the large extent to which the premaxillae
form the sides of the anterior extremity. Nasal bones elongated,
flat, and narrow, the opening of the anterior nares being over the
middle of the elongated compressed rostrum. All the cervical
vertebras free. The characters of the dorsal vertebras and mode of
articulation of the ribs appear to have resembled those of Platcmista
rather than Balcena, Physeter, or Delpliiaus. Lumbar vertebras
with elongated bodies, low neural spines, and the ti'ansverse pro-
cesses placed low down on the bodies. Characters of the limbs
not known with certainty. 3
All the known fossil remains belonging to the animals of this
group may be referred, provisionally at least, to the genus Zeuglodon,
so named because the first section of a molar tooth examined was
taken from the base of the crown, where it was beginning to divide
into the two roots, and looked like two single teeth " linked or
1 In a recent memoir Professor D'Arey Thompson lias brought forward some
arguments to show that the Zeuglodonts have no direct affinities with the Cetacea,
hut have on the other hand the strongest possible relation with the Pinnipede
Carnivora. ' ' On the Systematic position of Zeuglodon, " Studies from the Museum
of Zoology, Dundee, vol. i. No. 9, 1890.
2 An appearance in one specimen has been described by C. G. Carus as in-
dicating a vertical succession of the teeth, but the evidence upon which this rests
is by no means satisfactory, and appears to admit of another explanation.
3 A mutilated humerus of Zeuglodon cctoidcs has given rise to many con-
jectures, appearing to some anatomists to indicate seal-like freedom of motion
at the elbow-joint, while to others its characters appear to be truly Cetacean.
PHYSETERIDsE 247
yoked together." This name was substituted by Owen for the
earlier one Basilosawrus of Harlan, with the consent of that author,
on the mammalian nature of the animal being demonstrated. 1 The
latter name is, however, still generally retained by American
zoologists. The remains have hitherto been found chiefly in the
Eocene formations of the States of Alabama, Louisiana, Mississippi,
and Arkansas, and have been assigned to several species. A portion
of a skull is recorded from the Barton Clay (Eocene) of Hampshire,
England.
Suborder Odontoceti,
the Delphinoidea, or Toothed Whales.
Calcified teeth always present after birth ; generally numerous,
but sometimes a very limited number (in a few cases none) are
functionally developed. No baleen. Upper surface of the skull
more or less asymmetrical. Nasal bones in the form of nodules or
flattened plates, applied closely to the frontals, and not forming
any part of the roof to the narial passage, which is directed upwards
and backwards. Olfactory organ rudimentary or absent. Hinder
end of the maxilla expanded and covering the greater part of the
orbital plate of the frontal bone. Lachrymal bone either inseparable
from the jugal, or, when distinct, very large, and forming part of
the roof of the orbit. Tympanic bone not ankylosed with the
periotic, which is usually only attached to the rest of the skull by
ligament. Rami of mandible nearly straight, much expanded in
height posteriorly, with a wide funnel-shaped aperture to the dental
canal, and coming in contact in front by a flat surface of variable
length, but always constituting a true symphysis. Several of the
anterior ribs with well-developed capitular processes, articulating
with the bodies of the vertebra?. Sternum almost always composed
of several pieces, placed one behind the other, with which several
pairs of ribs are always connected by the intervention of well-
developed cartilaginous or ossified sternal ribs. External respiratory
aperture single, the two nostrils uniting before they reach the
surface, usually in the form of a transverse subcrescentic valvular
aperture, situated on the top of the head. Manus always penta-
dactylous, though the first and fifth digits are usually very little
developed. No caecum, except in Platanista.
Family PHYSETERIDiE.
No functional teeth in the upper jaw. Mandibular teeth various,
often much reduced in number. Bones of the cranium raised so as
1 See Trans. Geol. Soc. ser. 2, vol. vi. p. 67.
248 CETACEA
to form an elevated prominence or crest behind the nares. Pterygoid
bones thick, produced backwards, meeting in the middle line, and
not involuted to form the outer wall of the post-palatine air-sinuses,
but simply hollowed on their outer side. Anterior facet of periotic
bone (Fig. 87) for articulation with the tympanic quite smooth;
and the posterior tympanic surface of the former broad, with a
median longitudinal ridge. Transverse processes of the arches of
the dorsal vertebras, to which the tubercles of the ribs are attached,
ceasing abruptly near the end of the series, and replaced by
processes on the body at a much lower level, and not on a line or
serially homologous with them, but serially homologous anteriorly
with the heads of the ribs, and posteriorly with the transverse
processes of the lumbar vertebrae. (In some genera, as Physeter,
the two processes, upper and lower on each side, are both present
and well developed in the same vertebra in the region of transition.
In others, as Ziphius and Berardius, they are not both developed on
any single vertebra.) Costal cartilages not ossified.
Subfamily Physeterinae. — Numerous teeth in the mandible,
which are not set in distinct bony alveoli, but in a long groove
imperfectly divided by partial septa, and held in place by the
strong, fibrous gum surrounding them. No distinct lachrymal bone.
Cranium strikingly asymmetrical in the region of the narial
apertures, in consequence of the left opening greatly exceeding the
right in size.
Physeter. 1 — Upper teeth apparently of uncertain number, rudi-
mentary, and functionless, being embedded in the gum. Lower jaw
Fig. S2.— Skull of Sperm Whale {Physeter macrocephalus).
with from 20 to 25 teeth on each side, stout, conical, recurved, and
pointed at the apex until they are worn, without enamel. Upper
surface of the cranium concave ; its posterior and lateral edges
raised into a very high and greatly compressed semicircular crest
or wall. Zygomatic processes of jugal bones thick and massive.
Kostrum greatly elongated, broad at the base, and gradually tapering
1 Linn. Syst. Nat. 12th ed. vol. i. p. 107 (1766).
PH i 'SE TERID.E 249
to the apex. Upper edge of the mesethmoid forming a roughened
irregular projection between the narial apertures, inclining to
the left side. Mandible exceedingly long and narrow, the
symphysis being more than half the length of the ramus. Vertebras:
C 7, D 11, L 8, C 2-i ; total 50. Atlas free; all the other cervical
vertebrae united by their bodies and spines into a single mass.
Eleventh pair of ribs rudimentary. Head about one-third the
length of the body ; very massive, high and truncated, and rather
compressed in front ; owing its huge size and remarkable form
mainly to the accumulation of an oily substance secreted by
the lining membranes of great cells surrounding the narial passage
and filling the large hollow on the upper surface of the cranium
and overlying the rostrum. The single blowhole is longitudinal,
slightly sigmoid, and placed at the upper and anterior extremity
of the head to the left side of the middle line. The opening
of the mouth is on the under side of the head, considerably behind
the end of the snout. Pectoral fin short, broad, and obliquely
truncated. Dorsal fin a mere low protuberance.
The only representative of this genus is the Cachalot or Sperm
Fig. 83. — The Sperm Whale (Physeter macrocephalus),
Whale (P. macrocephalus, Fig. 83), one of the most colossal of
animals, quite equalling, if not exceeding, the Greenland Whale
in bulk. The length of the full-grown male is from 55 to
60 feet, but the female is stated not to reach more than half
that size. The general colour of the surface is black above and
gray below, the colours gradually shading into each other. The
Sperm Whale is one of the most widely distributed of animals,
being met with usually in herds or " schools " in almost all
tropical and subtropical seas, but not occurring, except accident-
ally, in the Polar regions. Not unfrequently specimens appear
on the coasts of the British Isles, but only as solitary stragglers,
or as dead carcases, floated northwards by the Gulf Stream. It
is remarkable that every one of these of Avhich we have an accurate
record has been an old male. The food of this Whale consists
mainly of various species of cephalopods (squid and cuttle-fish),
but fish of considerable size are also eaten. The substance called
"ambergris," formerly used in medicine and now in perfumery,
is a concretion formed in the intestine of this Whale, and is found
2;o CETACEA
floating on the surface of the seas it inhabits. Its genuineness is
proved by the presence of the horny beaks of the cephalopods on
which the Whale feeds.
The oil contained in the great cavity above the skull, when re-
fined, yields " spermaceti," and the thick covering of blubber which
everywhere envelops the body produces the valuable " sperm-oil "
of commerce ; hence this animal has long been the subject of a
regular chase, by which its numbers have been greatly diminished.
Cogia. 1 — Teeth of the upper jaw absent, or reduced to a rudiment-
ary pair in front ; in the lower jaw 9 to 1 2 on each side, rather long,
slender, pointed, and curved, with a coating of enamel. Upper
surface of the cranium concave, with thick, raised posterior and
lateral margins, massive and rounded at their anterior terminations
above the orbits. Upper edge of the mesethmoid forming a pro-
minent sinuous ridge, constituting a kind of longitudinal septum
to the base of the great supra-cranial cavity. Rostrum not longer
than the cranial portion of the skull, broad at the base, and rapidly
tapering to the apex. Zygomatic process of the jugal styliform.
Mandible with the symphysis less than half the length of the entire
ramus. Vertebras : C 7, D 13 or 14, L and C 30 ; total 50 or 51.
All the cervical vertebras united by their bodies and arches. Ex-
ternal characters not well known, but, judging by the somewhat
conflicting accounts of those that have had an opportunity of ob-
serving them, the head is about one-sixth of the length of the body,
and obtusely pointed in front ; the mouth small, and placed far
below the apex of the snout ; the spiracle crescentic, and placed
obliquely on the top of the head anteriorly to the eyes, and to the
left of the middle line ; the pectoral fins are obtusely falcate ; and
there is a triangular dorsal fin.
The history of this genus is a good illustration of the difficulties
in which the study of the Cetacea has been involved by the super-
ficial manner in which it has been investigated. The first known
example, a skull from the Cape of Good Hope in the Paris Museum,
was described by De Blainville under the name of Physeter breviceps.
This was afterwards with good reason generically separated by Gray.
Until Avithin a very feAv years ago only five other individuals had
been met with, each of which had been described under a different
specific name (viz. grayi, macleayi, simus, flotceri, and potsii), and
which are arranged by Gray in two distinct genera. The most
careful examination of the description given of these specimens, or
of the now numerous osteological remains available, fails to detect
any differences beyond those which may be attributed to age or sex,
and hence, according to our present knowledge, these six supposed
species must all be included under one name, C. breviceps. This'
animal appears to attain the length of 10 feet when adult, and has
1 Gray, Zoology of Erebus and Terror, p. 22 (1846). Usually spelt Kogia.
PH ] 7 SE TERIDAL 2 5 r
been met with at various distant localities in the Southern Ocean,
and also oft' the coast of Madras and in the North Pacific.
Extinct Physeteroids. — Teeth of Physeteroids are of very common
occurrence in the Belgian and English Crags, and evidently indicate
the former existence of Whales more or less closely allied to the
Sperm "Whale, but often distinguished by the presence of an enamel-
cap on the crowns of the teeth. The generic determination of these
teeth is, however, exceedingly difficult, owing to the water-worn
condition in which they are frequently found, and also on account
of the impossibility of knowing whether small and large teeth may
not be referable to different parts of the jaws of the same species
or to individuals of different ages. Moreover, in the cases of
isolated teeth it is impossible to know how many were contained
in the jaws, and therefore to distinguish Physeteroid from Ziphioid
teeth. Physeterula is a small form about one-third the dimensions
of the Sperm Whale, and distinguished by the length of the mandib-
ular symphysis being only about one-third that of the entire ramus ;
it is identified by Professor Cope with Cogia. Eucetus (Dinozij)hius) is
founded on teeth which are regarded as closely resembling those of
Physeter, but distinguished by their subcylindrical form and the
small size of the aperture of the pulp-cavity. It does not appear,
however, to be certain that these teeth are not worn specimens of
those described as Scaldicetus. Physetodon, from the Pliocene of
Australia, is founded upon the evidence of similar teeth. The teeth
from the Belgian Crag described as Scaldicetus are somewhat smaller
than those of the Sperm Whale, and are readily characterised by
their cap of grooved enamel. Other teeth with enamel -caps have
been described as Physodon and Hoplocctus. The genus Balcetiodon
is founded upon a very imperfect large tooth from the English Crag,
which is not sufficiently well preserved to admit of exact comparison
with the other types.
Subfamily Ziphiinse. — Teeth of the mandible (at least in existing
forms) quite rudimentary and concealed in the gum, except one, or
very rarely two, pairs which may be largely developed, especially
in the male sex. A distinct lachrymal bone. Externally the mouth
is produced into a slender rostrum or beak, from above which the
rounded eminence formed by a cushion of fat resting on the cranium
in front of the blowhole rises somewhat abruptly. Spiracle or
blowhole single, crescentic, median, as in the Delphinida?. Pectoral
fin small, ovate, the five digits all moderately well developed. A
small obtusely falcate dorsal fin situated considerably behind the
middle of the back. Longitudinal grooves on each side of the skin
of the throat, diverging posteriorly, and nearly meeting in front.
In external characters and habits the animals of this group closely
resemble each other. They appear to be almost exclusively feeders
on various species of cephalopods, and occur either singly, in pairs,
252 CETACEA
or in small herds. By their dental and osteological characters they
are easily separated into four distinct genera.
Hyperobdon. 1 — A small conical pointed tooth at the apex of each
ramus of the mandible, concealed by the gum during life. Skull
with the upper ends of the premaxillae rising suddenly behind the
nares to the vertex and expanded laterally, their outer edges
curving backwards and their anterior surfaces arching forwards and
overhanging the nares ; the right larger than the left. Nasal bones
lying in the hollow between the upper extremities of the premaxillse,
strongly concave in the middle line and in front ; their outer edges,
especially on the right side, expanded over the front of the inner
border of the maxilla. Very high longitudinal crests on the
maxillffi at the base of the rostrum, extending backwards almost to
the nares, approaching each other in the middle line above ; some-
times so massive that their inner edges come almost in contact.
Anteorbital notch distinct. Mesethmoid but slightly ossified.
Vertebra: C 7, D 9, L 10, C 19 ; total 45. All the cervical
vertebra? united. Upper surface of the head in front of the blow-
Fig. 84.— Hyperoodon rostratus. From a female specimen taken off the coast of Scotland, 1SS2.
hole very prominent and rounded, rising abruptly from above the
small, distinct snout.
The genus is known typically by H. rostratus (Fig. 84), but an
imperfect skull has been made the type of H. planifrons — a species
differing considerably in cranial characters from the typical one.
The females and young males of the first-named species have the
contour of the head of the same general form as in Fig. 84 ; the
premaxillary crests of the cranium being widely separated from
one another, and terminating in comparatively sharp edges. In the
males, however, as age advances the summits of these crests become
gradually expanded and flattened, till they are almost or quite in
contact in the middle line. This development of the maxillary
crests produces a corresponding elevation and flattening of the front
of the head, so that in very old males this aspect presents a flattened
disc -like surface rising abruptly from the beak (which thus
becomes almost buried) and situated in a plane nearly at right angles
to the line of the back. 2 So different, indeed, is the appearance of
the skull of an old male from that of a female individual that
1 Lacepkle, "Table des Ordres," Hid. Nat. des Citads, p. xliv. (1804).
2 See the figures in the Proc. Zool. Soc. 1882, pp. 728, 729.
PH \ 'SE TERIDsE 1 5 3
it was long considered that they belonged to different species —
the male form having been described as if. laiifrons. The length
of an adult male reaches 30 feet, while that of the female does not
exceed 24 feet.
The Hyperoodon, sometimes called " Bottlenose," a name also
vaguely given to several species of Dolphin, is a regular inhabitant
of the North Atlantic, passing the summer in the Spitzbergen seas
and going farther south in winter. It resembles the Sperm Whale
in possessing a large store of oil in the upper part of the head,
which yields spermaceti when refined ; on this account, and also
for the sake of the blubber, which supplies an oil almost indis-
tinguishable from sperm-oil, this Whale has been the object of a
regular chase in recent years.
The following account of its habits is taken from a paper
by Captain D. Gray, published in the Zoological Society's Proceedings
for 1882 :—
" These Whales are occasionally met with immediately after
leaving the Shetland Isles in March, and north across the ocean
until the ice is reached, near the margin of which they are found
in the greatest numbers ; but they are seldom seen amongst it.
Although it is not in their nature to keep in amongst the ice, they
like to frequent the open bays for the shelter it gives them from
the sea. Sometimes a point of ice overlaps them ; it is then only
that they are seen going out again towards the ocean. They are
also to be met with from the entrance of Hudson's Straits and up
Davis's Straits, as far as 70° N. lat., and down the east side
round Cape Farewell, all round Iceland, north along the Greenland
ice to 77° N. lat. ; also along the west coast of Spitzbergen,
and east to Cherry Island in lat. 72° N. and long. 19° E. Beyond
these limits I have never seen them ; but doubtless they are to be
found as far as the Straits of Belle Isle on the west, and east to
Nova Zembla. From the fact that they are not seen in summer
farther south than a day's sail from the ice, it would appear that
they migrate south in the autumn, and north again in the spring.
They are gregarious in their habits, going in herds of from four
to ten. It is rare to see more than the latter number together,
although many different herds are frequently in sight at the same
time. The adult males very often go by themselves ; but young
bulls, cows, and calves, with an old male as a leader, are sometimes
seen together. They are very unsuspicious, coming close alongside
the ship, round about underneath the boats, until their curiosity
is satisfied. . . . They vary in colour from black in the young to
light brown in the older animals. The very old turn almost yellow,
the beak and front of the head being quite white, •with a white
band round their necks ; all of them are grayish-white on the belly.
They can leap many feet out of the water, even having time while
!54 CETACEA
in the air to turn round their heads and look about them, taking
the water head first, and not falling helplessly into it sideways like
the larger whales. The full-grown whale is 30 feet long by 20
feet in circumference, and yields two tons of oil besides two hundred-
weight of spermaceti. . . . Their ordinary food consists of a bluish-
white cuttle-fish, six inches long by three inches in circumference,
and pointed towards the tail. . . . They evidently have a great
depth to go to find them, judging from the length of time that
they remain away, and from the long heavy blasts they make on
coming to the surface again."
Periotic bones of Hyperoodon are found in the Red Crag of
Suffolk, presenting no character by which they can be specifically
distinguished from those of the common existing species.
Ziphius. 1 — A single conical tooth of moderate size on each side
of the mandible close to the anterior extremity, and directed
forwards and upwards. Skull with the premaxillee immediately in
front of, and at the sides of the nares expanded, hollowed, and with
elevated lateral margins, the posterior ends rising to the vertex and
curving forwards, the right being considerably more developed than
the left ; the conjoint nasals forming a strongly pronounced sym-
metrical eminence at the top of the cranium, projecting forwards
over the nares, flat above, most prominent and rounded in the
middle line in front, and separated by a notch on each side from
the premaxillse. Anteorbital notch not distinct. Rostrum (seen
from above) triangular, gradually tapering from the base to the
apex ; upper and outer edges of maxilla? at base of rostrum raised
into low roughened tuberosities. Mesethmoid cartilage densely
ossified in adult age, and coalescing with the surrounding bones of
the rostrum. Vertebrae : C 7, D 10, L 10, C 22 ; total 49. The
three anterior cervical vertebra? united, the rest free.
The type of this genus is Z. cavirostris of Cuvier, founded upon
an imperfect skull picked up in 1804 on the Mediterranean coast
of France, and described and figured in the Ossemens Fossiles under
the impression that it was that of an extinct species. Many other
individuals have, however, been subsequently met with in various
parts of the world, from the Shetland Islands to New Zealand, all
referable to the same genus, if not to the same species ; although,
as is usual in such cases, they have mostly been described under
different names, the so-called genera Petrorhynchus and Epiodon
being probably referable to the type species.
It is quite probable that some of the Physeteroid teeth from the
Crag deposits mentioned on p. 251 may be referable to Ziphius.
Mesoplodon. 2 — A much compressed and pointed tooth in each
1 Cuvier, Ossemens Fossiles, 2d ed. vol. v. p. 352 (1823).
2 Gervais, Ann. Sci. Nat. ser. 3, vol. xiv. p. 16 (1S50). For the very com-
plicated synonymy of this genus, see Trans. Zool. Soc. vol. viii. p. 208.
PHYSETERin.E
=55
ramus of the mandible, variously situated, Imt generally at some
distance behind the apex (Fig. 86); its point directed upwards, and
often somewhat backwards, occasionally developed to a great size.
Fig. S5.— Mesoplodon bidens. From Reinhardt.
Skull with the region around the nares as in Hyperoodun, except
that the nasals are narrow and more sunk between the upper ends
of the premaxilla? ; like those of Hyperoodon, they are concave in
the middle line in front and above. No maxillary tuberosities.
Anteorbital notch not very distinct. Eostrum long, narrow, and
solid throuo-hout. Mesethmoid in adult ase ossified in its entire
throughout.
Fig. S6. — Left lateral view of skull of Mesoplodon densirostris.
length, coalescing with the surrounding bones, and showing as a
narrow band on the upper surface of the rostrum. Vertebrae :
C 7, D 10, L 10 or 11, C 19 or 20 ; total 46 to 48. Two or three
anterior cervicals united, the rest usually free.
Though varying in form, the mandibular teeth of the different
members of this genus agree in their essential structure, having a
small and pointed enamel-covered crown, composed of true dentine,
which, instead of surmounting a root of the ordinary character, is
raised upon a solid mass of osteodentine. The continuous growth of
this greatly alters the form and general appearance of the organ
as age advances, as seen most strikingly in the case of M. layardi,
where the long, narrow, flat, strapdike teeth, curving inwards at
their extremities, actually meet over the rostrum, and must greatly
interfere with the movements of the jaw. In one species (M. grayi)
a row of minute, conical, pointed teeth, like those of ordinary
Dolphins, 17 to 19 in number, are present even in the adults, on
256
CETACEA
each side of the middle part of the upper jaw, but embedded by
their roots only in the gum, and not in bony alveoli. This fact,
Avith the frequent presence of rudimentary teeth in other species
of this and the last genus in both upper and lower jaws,
suggests the idea that the Ziphioids are derived from ancestral forms
which had teeth of normal character in both jaws ; the dentition
of the living forms having become greatly specialised. The existing
species of this genus are widely distributed in both northern and
southern hemispheres, but most frequent in the latter. The best
established are M. Helens, M. europceus, M. densirostris, M. layardi,
M. grayi, and M. hectori ; but there is still much to be learned with
regard to their distinctive characters and geographical distribution.
They were abundant in the Pliocene age, as attested by the fre-
quency with which the most im-
perishable and easily recognised
portion of their structure, the
long, cylindrical rostrum of the
skull, of more than ivory dense-
ness, is found among the rolled
Fig. S7.— The left periotic bone of Meso-
plodon; from the Red Crag of Suffolk. The
smooth concave surface in the right upper
corner of the figure forms the anterior ar-
ticulation with the tympanic. (From the
Cat. Foss. Mamm. Brit. Mus. pt. v. p. 70.)
and water -worn fragments of
animal remains which compose
the well-known "bone-bed" at
the base of the Red Crag of Suf-
folk. Several species have been
founded upon the evidence of
these rostra. Periotic bones of
this genus (Fig. 87) are of less common occurrence in the Crag ;
the figure is given to illustrate the characteristic features of this
bone in the present family.
Berardius. 1 — Two moderate-sized, compressed, pointed teeth on
each side of the symphysis of the mandible, with their apices directed
forwards, the anterior being the larger of the two and close to the
apex. Upper ends of the premaxillse nearly symmetrical, moder-
ately elevated, very slightly expanded, and not curved forward over
the nares. Nasals broad, massive, and rounded, of nearly equal
size, forming the vertex of the skull, flattened in front, most
prominent in the middle line. Anteorbital notch distinct. Rostrum
long and narrow. Mesethmoid only partially ossified. Small
rugous eminences on the outer edge of the upper surface of the
maxillae at base of rostrum. Vertebrate : C 7, D 10, L 12, C 19 ;
total 48. The three anterior cervicals ankylosed, the rest free and
well developed.
The only known species, B. arnuxi, attains the length of 30
feet, and has hitherto only been met with in the seas around New
Zealand.
1 Duvernoy, Ann. Sci. Nat.-Zoologie, ser. 3, vol. xv. p. 41 (1851).
SQUALODOXT/P.K 257
Chwiesiphius. 1 — The rostral portions of crania from the Antwerp
and Suffolk Crags, on the evidence of which this genus has been
established, agree with those of Mesqplodon in having the premaxillae
in contact with the intervening bones throughout the length of
their inner surfaces, and also in showing only a very small portion
of the vomer on the inferior surface ; they differ, however, in that,
the mesethmoid cartilage remains unossified, whereby a fistular
vacuity remains. In some species the soldering of the inner
surfaces of the premaxillae is incomplete. The interorbital region
of the skull is flat ; and there are two pits in the nasal region, of
which the right is the larger.
Family Squalodontid--e.
Numerous extinct forms, chiefly known by teeth and fragments
of crania, may be provisionally placed here, until more of their
osteological characters shall be brought to light. They differ from
all existing Cetaceans in having the teeth distinctly differentiated
into groups, as in the Archajoceti, the posterior molars being two-
rooted. The cranium has, however, none of the distinguishing
characteristics of the Zeuglodonts, but essentially resembles that of
the Odontoceti, especially in the position of the anterior nares and
form of the nasal bones.
Squalodon.^ — All the forms may be included in this genus, the
so-called Ehizoprivii not being distinct. Dentition : i § , c \, simple
teeth of the molar series (premolars 1) f , two-rooted molars -f = \f ;
total 60. The double-rooted molars differ from those of Zeuglodon
in having the denticulations of the crown confined to the posterior
border, or at all events much less developed on the front edge.
Very little is known of the structure of these animals beyond the
skull and teeth, fragments of which have been found widely
distributed throughout the marine Miocene and early Pliocene
formations of Europe, especially in the Vienna basin, many parts
of France, and the Antwerp and Suffolk Crags. They have also
been found in formations of corresponding age in North America
and South Australia. A few isolated teeth have been met with in
the cave-deposits of Italy, which, if contemporaneous with the beds
in which they occur, indicate the survival of the genus into the
Pleistocene period.
Family Platantstid^.
Under this heading may be placed three very singular genera,
which, though differing considerably from each other, have several
1 Duvernoy, op. cit. p. 61.
2 Grateloup, Act. Ac. 11. Sci. Bordeaux, 1840, p. 208.
17
> 5 8
CETACEA
points in common, and do not altogether come under the definition
either of the Physeteridce or the Delphi n nice, especially in the
important character of the mode of articulation of the ribs with
the dorsal vertebrae, the tubercular and capitular articulations,
distinct at the commencement of the series, gradually blending
together, as they do in most ordinary mammals. The cervical
vertebra? are all free. The lachrymal bone is not distinct from the
jugal. The jaws are long and narrow, with numerous teeth in
both. The symphysis of the mandible exceeds half the length of
the whole ramus. Externally the head is divided from the body
by a slightly constricted neck. Pectoral limbs broad and truncated.
Dorsal fin small or obsolete. Fluviatile or estuarine in habits.
There are three distinct genera, which might almost be made the
types of families, but it is probably more convenient to keep them
together, only regarding them as representing three subfamilies.
Platanista. 1 — Teeth about %% on each side, set near together,
rather large, cylindrical, and sharp-pointed in the young ; in old
animals acquiring a large laterally compressed base, which in the
posterior part of the series becomes irregularly divided into roots.
As the conical enamel-covered crown wears away, the teeth of the
young and old animals have a totally different appearance. The
rostrum and dentigerous portion of the mandible are so narrow
that the teeth of the two sides are almost in contact. Maxillae sup-
porting very large, incurved, compressed bony crests, which over-
arch the nares and base of the rostrum, and almost meet in the
middle line above. Orbits very small and eyes rudimentary, without
crystalline lens. External respiratory aperture longitudinal, linear.
Vertebra? : C 7, D 10, L 9, C 26 ; total 52. A small caecum. No
pelvic bones. Dorsal fin represented by a low ridge.
One species, P. gangetica, entirely fluviatile, being extensively
distributed throughout nearly the whole of the river systems, not
Fig. SS.— Platanista gangetica. (From Anderson.)
only of the Ganges, but of the Brahmaputra and Indus, ascending
as high as there is water enough to swim in, but never passing out
to sea. It is quite blind, and feeds on small fish and crustaceans,
groping for them with its long snout in the muddy water at the
bottom of the rivers. It attains the length of 8 feet. 2
J Wagler, Syst. Amphib. etc., p. 35 (1S30).
- The anatomy of Platanista is fully described by J. Anderson, Zoological
Results of Two Expeditions to JFestcm Yunnan, 1878.
PLATANIST1DAZ 259
I iiia. 1 — Teeth variable, from 2G to 33 on either side of each jaw;
those at the posterior part with a distinct tubercle at the inner side
of the base of the crown. Vertebrae : C 7,1) 13, L 3, C 18 ; total
41. Transverse processes of lumbar vertebra? very broad. Sternum
short and broad, and consisting of a single segment only. Dorsal
tin a mere ridge. The long cylindrical rostrum externally furnished
with scattered, stout, and crisp hairs. One species only is known,
/. geqffroyensis, about 7 feet in length, inhabiting the upper Amazon
and its tributary streams.
Pontoporia. 2 — Teeth 50 to 60 on either side of each jaw, with a
cingulum at the base of the crown. Jaws very long and slender.
Vertebrae: C 7, D 10, L 5, C 19; total 41. Transverse processes
of the lumbar vertebra? extremely broad. Sternum elongated,
composed of two segments, with four sternal ribs attached. Dorsal
fin rather small, triangular, pointed. External respiratory aperture
Fig. S9. — Pontoporia blainvlllei. (From Burmeister.)
transverse, crescentic. This genus connects the last two forms with
the true Delphinidce. The only species, P. blainvilki, is one of the
smallest members of the whole order, not exceeding 5 feet in length.
It has only been met with at the mouth of the Rio de la Plata, near
Buenos Ayres, and there is at present no evidence that it ascends
into the fresh waters of the river.
Fossil forms. — Remains of a Cetacean from the Pleistocene of
South America were referred by Bravard to Pontoporia, but they
have been regarded by other writers as indicating a distinct genus,
for which the names Palceopontoporia and Pontistes have been pro-
posed. The Upper Tertiary European genera Champsodelphis and
Schizodelphis are generally referred to the present family. The
former has wide transverse processes to the lumbar vertebrae, as in
In in, while the teeth also resemble those of that genus. In Schizo-
delphis the form of the rostrum presents a great resemblance to that
of the Delphinoid genus Stem, but the symphysis of the mandible
is relatively longer. A number of fossil Cetaceans from the
Miocene of the United States, such as Priscodelphinus, Lophocetus,
Ixacanthus, Rhabdosteus, etc., are referred by Professor E. D. Cope to
1 D'Orbigny, Nbuv, Ann. Mus. Paris, vol. iii. p. 31 (1834).
2 Gray, Zoology of Erebus and Terror, p. 46 (1S46).
260 CETACEA
this family. Agabelus, from the same deposits, is an apparently
allied, but toothless type.
Family Delphinid^e.
Teeth usually numerous in both jaws. Pterygoid bones short,
thin, each involuted to form with a process of the palate bone the
outer Avail of the post-palatine air-sinus. Symphysis of mandible
short, or moderate, never exceeding one-third of the length of the
ramus. Lachrymal bone not distinct from the jugal. The anterior
facet on the periotic (Fig. 96) for articulation with the tympanic
deeply grooved ; and the posterior tympanic surface of the same
bone comparatively narrow, with its ridge for articulation Avith the
free border of the tympanic ill-defined, and situated close to one
edge. Transverse processes of the dorsal vertebrae gradually trans-
ferred from the arches to the bodies of the vertebrae Avithout any
sudden break, and becoming posteriorly continuous serially AA r ith the
transverse processes of the lumbar vertebrae. Anterior ribs attached
to the transverse process by the tubercle, and to the body of the
vertebra by the head ; the latter attachment lost in the posterior
ribs. Sternal ribs firmly ossified. External respiratory aperture
transverse, crescentic, with the horns of the crescent pointing
forwards.
A very large group, closely united in essential characters but
presenting great modifications in details. The different types are
mostly so connected by intermediate or osculant forms that there
are great difficulties in grouping them into natural subfamilies.
Even the formation of Avell- defined genera is by no means satis-
factory in all cases. They may, hoAvever, be divided, perhaps
artificially, into two groups.
Group A. — Head rounded, without distinct rostrum or beak.
Rostrum of skull about as long as cranial portion.
Monodon} — Besides some irregular rudimentary teeth, the entire
dentition is reduced to a single pair of teeth which lie horizontally
in the maxilla, and in the female remain permanently concealed
within the alveolus, so that this sex is practically toothless, while
in the male (see Fig. 90) the right tooth usually remains similarly
concealed and abortive, and the left is immensely developed, attaining
a length equal to more than half that of the entire animal, projecting
horizontally from the head in the form of a cylindrical, or slightly
tapering, pointed tusk, Avithout enamel, and Avith the surface
marked by spiral grooves and ridges, running in a sinistral direction.
(When, as occasionally happens, both tusks are developed, the
spiral grooves have the same direction in each.) Pterygoids very
1 Linn. Syst. Nut. 12th ed. vol. i. p. 105 (1766).
DELPHIXID.E
:6i
small, not meeting in the middle line, bu1 approxi-
mating posteriorly. Vertebrae : C 7, 1) 11, L G,
C 2G ; total 50. Cervical region comparatively
long, and all the vertebrae distinct, or with ir-
regular unions towards the middle of the series,
the atlas and axis being usually free. Manus
small, short, and broad ; second and third digits
nearly equal, fourth slightly shorter. No dorsal
fin.
This genus is now represented only by the
well-known Narwhal (.1/. monoceros), in which the
horn -like tusk of the male often grows to a
length of 7 or 8 feet. In very young animals
several small additional teeth, irregular in number
and position, are present, but these usually dis-
appear soon after birth.
The head is rather short and rounded ; the
fore limbs or paddles are small and broad com-
pared with those of most Dolphins ; and (as in the
Beluga) the median dorsal fin, found in nearly
all other members of the group, is wanting or
replaced by a low ridge. The general colour of
the surface is dark gray above and white below,
but variously marbled and spotted with different
shades of gray. In the general contour of the
body the Narwhal resembles the White Whale
or Beluga.
The Narwhal is essentially an Arctic animal,
frequenting the icy circumpolar seas, and but
rarely seen south of 65° N. lat. Three instances
have, however, been recorded of its occurrence
on the British coasts, one in the Firth of Forth
in 1648, one near Boston in Lincolnshire in 1800
while a third, which entangled itself among
the rocks in the Sound of Weesdale, Shetland,
in September 1808, is described by Fleming
in the Memoirs of the Wernerian Society, vol. i.
Like most other Cetaceans, it is gregarious in
its habits, being usually met with in " schools "
or herds of fifteen or twenty individuals. Its
food appears to be various species of cephalo-
pods, small fishes, and crustaceans. The pur-
pose served in the animal's economy by the
wonderfully developed asymmetrical tusk — or
" horn," as it is commonly but erroneously
called — is not known. As it is present only
£ o
262
CETACEA
in the male sex, no function essential to the well-being of the
individual, such as the procuring of sustenance, can be assigned
to it, but it must be looked upon as belonging to the same cate-
gory of organs as the antlers of deer, and perhaps may be
applied to similar purposes. Very little is, however, known of the
habits of Narwhals. Scoresby describes them as "extremely
playful, frequently elevating their horns and crossing them with
each other as in fencing." They have never been known to charge
and pierce the bottom of ships with their weapons, as the swordfish
often does. The name " Sea Unicorn," sometimes applied to the
Narwhal, refers to the resemblance of its tusk to the horn
represented as projecting from the forehead of the fabled unicorn.
The ivory of which the tusk is composed is of very good quality,
but, owing to the central cavity, which extends the greater part of
its length, is only fitted for the manufacture of objects of small
size. The entire tusks are sometimes used for decorative purposes,
and are of considerable, though very fluctuating, commercial value.
Dclpldnapternx. 1 — This genus is closely allied to the last in ex-
ternal form, as well as anatomical structure, differing mainly in the
very distinct character of the dentition. Teeth from f- to \%,
occupying the anterior three-fourths of the rostrum and correspond-
ing portion of the mandible, rather small, conical, and pointed
when unworn, but usually becoming obliquely truncated, separated
by intervals considerably wider than the diameter of the tooth, and
implanted obliquely, the crowns inclining forwards, especially in
the upper jaw. Skull rather narrow and elongated, depressed.
Premaxillae convex in front of the nares. Rostrum about equal in
length to the cranial portion of the skull, triangular, broad at the
base, and gradually contracting towards the apex, where it is some-
Avhat curved downwards. Vertebra? : C 7, D 11, L 9, C 23 ; total 50.
Cervical vertebrae free. Manus broad, short, and rounded, all the
digits being tolerably well developed, except the first. No dorsal
fin, but a low ridge in its place.
Fig. 91.— Beluga or White Whale (Delphinapterus leucas). From a specimen taken in the river
St. Lawrence, and exhibited in London, 1877.
One existing species, I), leucas (Fig. 91), the
Beluga or
White
Whale, so called from its pure white colour, about 12 feet long,
abundant in the Arctic seas, and extending as far south on the
Lacepede, Hist. Nat. dcs Citads, p. xli. (1S04).
PF./.rillXID.E
263
American coast as the river St. Lawrence, which it ascends for a
considerable distance. On rare occasions it has been seen on the
(Mast of Scotland.
Remains of a Cetacean from the Lower Pliocene of Tuscany have
been referred by Brandt to this genus under the name IK brocchii
In all the remaining genera of Delphinidce the cervical region of
the vertebral column is very short, and the first two, and usually
more, of the vertebra' are firmly united.
Phoccena. 1 — Teeth §-£, small, occupying nearly the whole length
of the rostrum, with compressed, spade-shaped crowns, separated
from the root by a constricted
-".■ ' '_ ■■<•,,
Teeth of Porpoise. Twice natural size.
rising
neck (Fig. 92). Rostrum rather
shorter than the cranium
proper, broad at the base and
tapering towards the apex.
Premaxilla? raised into tuber-
osities in front of the nares.
The frontal bones forming a
somewhat square, elevated pro-
tuberance in the middle line of the skull behind the nares
altogether above the flattened nasals. Pterygoids very small,
and widely separated in the middle line. Symphysis of mandible
very short. Vertebra? : C 7, D 13, L 14, C 31 ; total 65 (subject
to slight individual variations). First to sixth cervical vertebra?,
and sometimes the seventh also, coalesced. Manus of moderate
size, oval, slightly falcate ; second and third digits nearly equal in
length ; fourth and fifth well developed, but shorter. Dorsal fin
near the middle of the back, triangular ; its height considerably less
than the length of the base ; its anterior edge frequently furnished
with one or more rows of conical horny tubercles.
The common Porpoise (Fig. 93), P. communis, is the best known
of British Cetaceans. The word Porpoise (sometimes spelled Porpus
and Porpesse) is apparently derived from the French pore and
■fiui .<.<!) a, or the Italian porco and pesce, and thus corresponds with
some of the English vernacular appellations, " hog-fish," " sea-hog,"
"herring-hog," and the German MaTudiwein, whence the usual modern
French name of the animal, merman. " Porpoise " is commonly used
by sailors to designate all the smaller Cetaceans, especially those
numerous species which naturalists call " Dolphins "; but in scientific
language it is restricted to the genus Phoccena of Cuvier, of which the
Porpoise of the British seas, Phoccena commwiis, Cuvier (Delphinus
phoccena, Linnaeus), is the type.
The Common Porpoise, when full grown, attains a length of 5
feet or a little more. The dimensions of an adult female specimen
from the English Channel were as follows : — length in straight line
1 Cuvier, Piigne Animal, vol. i. p. 279 (1817).
>6 4
CETACEA
from nose to median notch between the flukes of the tail, 62§
inches ; from the nose to the anterior edge of the dorsal fin, 29
inches ; height of dorsal fin, 4 J inches ; length of base of dorsal fin,
8 inches ; length of pectoral fin, 9} inches ; breadth of pectoral fin,
3h inches; breadth of tail flukes, 13 inches. The under jaw
projects about half an inch beyond the upper one. The aperture
of the mouth is tolerably wide, and is bounded by stiff immobile
lips, and curves slightly upwards at the hinder end. The eye is
small, and the external ear represented by a minute aperture in the
skin, scarcely larger than would be made by the puncture of a pin,
situated about 2 inches behind the eye. The pectoral fins are of
Fig. 93. — The Common Porpoise (Phoccena communis).
moderate size, and slightly falcate. The upper parts are dark gray,
or nearly black, according to the light in which they are viewed,
and the state of moisture or otherwise of the skin ; the under parts
are pure Avhite. The line of demarcation between these colours is
not distinct (washes or splashes of gray encroaching upon the
white on the sides), and varies somewhat in different individuals.
Usually it passes from the throat (the anterior part of which, with
the whole of the under jaw, is dark) above the origin of the
pectoral fin, along the middle of the Hank, and descends again to
the middle line before reaching the tail. Both sides of the pectoral
and caudal fins are black.
The Porpoise is sociable and gregarious in its habits, being usu-
ally seen in small herds, and frequenting coasts, bays, and estuaries
rather than the open ocean. It is the commonest Cetacean in the
seas around the British Isles, and not unfrequently ascends the
DELPHI X I P.K
river Thames, having been seen as high up as Richmond ; it has
also been observed in the Seine at Neuilly, near Paris. It frequents
the Scandinavian coasts, entering the Baltic in the summer ; and
is found as far north as Baffin's Bay, and as far west as the coasts
oi the United States. Southward its range is more limited than
that of the Common Dolphin, as, though very common on the
Atlantic coasts of France, it rarely enters the Mediterranean.
It feeds on fish, such as mackerel, pilchards, and herrings, of
which it devours large quantities, and, following the shoals, is often
caught by fishermen in the nets along with its prey. In former
times it was a common and esteemed article of food in England and
in France, but is now rarely if ever eaten, being commercially
valuable when caught only for the oil obtained from its blubber.
Its skin is sometimes used for leather and boot- thongs, but
the so-called "porpoise hides" are generally obtained from the
Beluga.
A closely similar if not identical species from the American
coast of the North Pacific has been described under the name of
Pkocoem vomerina, and another from the mouth of the Bio de la
Plata as P. spinipmnis.
The stomach of the Porpoise (Fig. 94) may be taken as a typical
example of this
organ in the Ceta-
cea. The first and
by far the largest
compartment (b)
may be regarded
as a kind of crop,
or dilatation of
the large oeso-
phagus (a). It is
lined by a thick
white epithelium,
which ceases
abruptly at the
entrance into the
next cavity. It
corresponds to
the cardiac com-
partment of the
stomach in the
Ungulates and
certain Bodents ;
but, although its
walls do not appear to contain peptic glands, its contents undergo
partial digestion — probably caused by the regurgitation into it
Fig. 94. — Diagrammatic section of the stomach of the Porpoise.
a, CEsophagus ; 6, left, or cardiac, compartment ; <:, middle compart-
ment ; d and e, the two divisions of the right, or pyloric, compart-
ment ; /, pylorus ; g, duodenum, dilated at its commencement ; h,
biliary duct.
266 CETACEA
of the secretions of the second, or true digestive compartment
(c). This, which is much smaller than the first, has very thick
walls, the mucous membrane being filled with numerous tubular
glands. The surface of this membrane is smooth and soft,
being thrown into numerous folds, which in this genus are arranged
in a very peculiar and characteristic manner, so as to form a
series of prominent longitudinal ridges, each of which sends off
short lateral ridges at right angles to itself, which interdigitate
with those proceeding from the next longitudinal ridge. The
remainder of the stomach (d to /) may be compared to the pyloric
antrum of the stomach of ordinary mammals. It is elongated,
cylindrical, and intestiniform, with a smooth lining membrane,
sharply bent upon itself, and terminating in a very small cir-
cular pyloric aperture (/). In the Porpoise the commence-
ment of this cavity is constricted off from the remainder, so as to
form a small globular sac. In most Dolphins (as Tursiops, Gldbi-
cephalus, and Grampus) there are two such small sacs of very similar
size and form, communicating by circular pylorus -like apertures ;
and in Hyperoodon the whole compartment is divided by a series of
constrictions into as many as seven separate cavities, which have
been regarded as distinct stomachs. Immediately beyond the
pylorus the duodenum has a globular dilatation, as in the camels
and some other Ungulates, into the lower end of which the biliary
duct (h) enters.
An allied species, differing mainly in the absence of dorsal fin,
and in the teeth (with the same form of crown) being fewer in
number and of larger size, called Delphinus pliomnoides by Cuvier,
/). melas by Schlegel, forms the type of Gray's genus Neomeris. 1
It is rather smaller than the Common Porpoise, and almost entirely
black in colour. Common off the coast of Bombay, it has been
met with in other parts of the Indian Ocean, and near Japan.
The British Museum recently received a specimen taken in the
Chinese river Yang-tse-kiang nearly a thousand miles from the
sea, which only differs from others from India in wanting a patch
of small horny tubercles on the back. As such tubercles are
present or absent in otherwise similar individuals of P. communis, it
is doubtful Avhether they can be regarded as constituting a specific
character.
Cephalorhynchus? — Rostrum as long and sometimes slightly
longer than the cranial portion of the skull. Pterygoids widely
separated from one another. Teeth small (less than 3 mm. in
diameter), #?- to f£. Vertebras: C 7, D 13, L 15, C 30; total 65.
Dorsal fin low, obtusely triangular or rounded. Pectoral fins rather
1 Zoology of Erebus and Terror, p. 30 (1S46). The name is preoccupied by
Lamarck for a genus of Polyzoa (1S16).
2 Gray, Cat. Cetacea Brit. Mas. p. 106 (1850).
DELPHINID.K 267
small, narrow, and ovate. Typified by C. heavisidei, from the
southern seas. C. eutropia is a very distinct form from the same
seas, known only by the skull, and referred provisionally to this
genus.
Orcetta. 1 — Teeth ] § to j }, small, conical, pointed, rather closely
set, and occupying nearly the whole length of the rostrum. Skull
subglobular, high. Rostrum nearly equal in length to the cranial
portion of the skull, tapering. Pterygoids widely separated from
one another. Manus of moderate size, not elongated, but some-
what pointed. All the bones of the digits broader than long,
except the proximal phalanges of the index and third fingers.
Dorsal fin rather small, placed behind the middle of the body.
Two species, both of small size — 0. brevirostris, from the Bay of
Bengal, and 0. fluminalis, from the Irawadi river, from 300 to
900 miles from the sea. Our present knowledge of the anatomy,
geographical distribution, and habits of these interesting Cetaceans
is almost entirely due to the researches of Dr. J. Anderson. 2
Orca. s — Teeth about |4, occupying nearly the whole length of
the rostrum, very large and stout, with conical recurved crowns,
and large roots, expanded laterally and flattened, or rather hollowed,
on the anterior and posterior surfaces. Rostrum about equal in
length to the cranial part of the skull, broad and flattened above,
rounded in front ; premaxillte broad and rather concave in front of
the nares, contracted at the middle of the rostrum, and expanding
again towards the apex. Pterygoids of normal form, but not quite
meeting in the middle line. Vertebrae: C 7, D 11-12, L 10,
C 23; total 51 or 52. Bodies of the first and second and some-
times the third cervical vertebrae united ; the rest free. Pectoral
fin very large, ovate, nearly as broad as long. All the phalanges
and metacarpals broader than long. General form of body robust.
Dorsal fin near the middle of the back, very high and pointed.
Anterior part of the head broad and depressed.
The animals composing this genus are met with in almost all
seas from Greenland to Tasmania, but the number of species is still
uncertain, and possibly they may be all reduced to one. They are
readily known, when swimming in the water, by the high, erect,
falcate dorsal fin, whence their common German name of Schwert-
fisch (Sword-fish). By English sailors they are generally known as
" Grampuses " or " Killers." They are distinguished from all their
allies by their great strength and ferocity, being the only Cetaceans
which habitually prey on warm-blooded animals, for, though fish
form part of their food, they also attack and devour Seals, and
1 Gray, Cat. Seals and Whales in Brit. Mus. p. 285 (1866).
2 Anatomical and Zoological Researches, comjmsing an Account of the Zoological
Results of the two Expeditions to Western Yunnan, in 1868 and 1875 (1878).
3 Gray, Zoology of Erebus and Terror, p. 33 (1846).
268
CETACEA
various species of their own order, not only the smaller Porpoises
and Dolphins, but even full-sized Whales, which last they combine
in packs to hunt down and destroy, as Wolves do the larger
Ruminants.
Fig, 95.— The Killer Whale, or Grampus {Orca gladiator). From Hunter.
Orca citoniensis, of the Italian Pliocene, was of smaller size than
the existing Killer. Teeth and periotic bones from the Suffolk Crag
not improbably belong to the same species.
Pseudorca. 1 — Teeth about i£. Cranial and dental characters
generally like those of Orca, except that the roots of the teeth are
cylindrical. Vertebras: C 7, D 10, L 9, C 24; total 50. First
to sixth or seventh cervical vertebras united. Bodies of the lumbar
vertebras distinguished from those of the preceding genera by being
more elongated, the length being to the width as 3 to 2. Pectoral
fin of moderate size, narrow, and pointed. Dorsal fin situated near
the middle of the back, of moderate size, falcate. Head in front of
the blowhole high, and compressed anteriorly, the snout truncated.
This genus was first known by the discovery of a skull in a
sub -fossil state in a fen in Lincolnshire, named by Sir Ft. Owen
Phocccna crassidens. Animals of apparently the same species were
afterwards met with in small herds on the Danish coast, and fully
described by Bernhardt. Others subsequently received from Tas-
mania were supposed at first to indicate a different species, but
comparison of a larger series of specimens from these extremely
distant localities fails to establish any characteristic difference, and
indicates an immense range of distribution for a species appar-
ently so rare. The length of this Cetacean is about 14 feet, and
its colour entirely black.
Globkephalus. 2 — Teeth g^|, confined to the anterior half of the
rostrum and corresponding part of the mandible, small, conical,
curved, sharp-pointed when unworn, sometimes deciduous in old
age. Skull broad and depressed. Rostrum and cranial portion
about equal in length. Upper surface of rostrum broad and flat.
1 Reinhardt, Overs. Dan. Sczsk. Fork. 1862, p. 151.
2 Lesson, N. Tab. d. BegTie Animal— Mamm. p. 200(1842).
DELPHIM1KK
269
Premaxillae strongly concave in front of the nures, as wide at the
middle of the rostrum as at the base, or wider, and very nearly or
completely concealing the maxillae in the anterior half of this
region. Pterygoids of normal form, meeting, or very nearly so,
in the middle line. Vertebrae: C 7, D 11, L 12-14, C 28-29;
total -">S or 59. Bodies of the anterior five or six cervical vertebrae
united. Leimth of the bodies of the lumbar and anterior caudal
vertebrae about equal to their width. Pectoral limb very long and
narrow, the second digit the longest, and having as many as 12
or 13 phalanges, the third shorter (with 9 phalanges), the first,
fourth, and fifth very short. Fore part of the head very round, in
consequence of the great development of a cushion of fat, placed
on the rostrum of the skull in front of the blowhole. Dorsal fin
low and triangular, the length of its base considerably exceeding its
vertical height.
The type of this well-marked genus is 67. melas, the Pilot
Whale, Ca'ing Whale, or Grindhval of the Faroe islanders, which
attains the length of 20 feet, and is of nearly uniform black colour,
except the middle of the under surface, which is lighter. These
animals are extremely gregarious, and, unlike the Killers, are mild
and inoffensive in disposition, feeding principally on cephalopods.
Their eminently sociable character constantly leads to their destruc-
tion, since when attacked they instinctively rush together and
blindly follow the leaders of the herd. When they are seen in
the neighbourhood of land, the fishermen endeavour to
ward of them in their boats, and with shouting and
to drive them into a bay or fjord, pursuing them until they run
themselves on shore in their alarm. In this way many hundreds
at a time are frequently driven ashore
and killed, when a herd enters one of
the bays or fjords of the Faroe Islands
or north of Scotland. Animals of this
well-marked genus are found in nearly
all seas, and their specific distinctions
are not yet made out. Specimens from
the Australian coasts, where they are
generally called " Blackfish," are quite
indistinguishable, either by external or
osteolouical characters, from those of the
North Atlantic.
Teeth, periotic (Fig. 96) and tym-
get to sea-
firing of
guns
panic bones from the Suffolk Crag,
Fig. 90. — The left periotic bone
of Globiccpludus uncidens ; from the
Suffolk Crag. Natural size. The
grooved surface on the right is the
anterior facet for articulation with
the tympanic ; the posterior tym-
panic articulation being on the op-
posite side of the figure. (From the
Cat. Foss. Mamm. Brit. Mus. pt. v.)
described as G. imcidens, indicate a form
apparently closely allied to the existing
species. The periotic is figured in order to illustrate the dis-
tinctive characters of that bone in the DeVphinidce.
270 CETACEA
Grampus. 1 — Teeth none in the upper jaw ; in the mandible few
(3 to 7 on each side), and confined to the region of the symphysis.
Vertebra?: C 7, D12, L 19, C 30 ; total 68. General external
characters much as in Globicephalus, but the fore part of the head
less rounded, and the pectoral fin less elongated.
But one species, G. griseus, is certainly known, about 13 feet
long, and remarkable for its great variability of colour. It has
been found, though rarely, in the North Atlantic and Mediterranean.
A skull from the Cape of Good Hope, which differs slightly from
that of the above, has been described under the name of G. richard-
soni.
Fcresia. 2 — This genus, known at present only by two skulls,
may be provisionally placed here. These appear to indicate a form
connecting Globicephalus, Grampus, and Lagenorhynchus. From the
latter they differ chiefly in the smaller number (about ^-f) and much
larger size (6-7 mm. in diameter at base of crown) of the teeth.
Lagenorhynchus. 3 — Rostrum scarcely exceeding the length of the
cranium, broad at the base and gradually tapering towards the
apex, depressed. Pterygoids normal, meeting in the middle line.
Teeth small (not exceeding 4 mm. in diameter), ff to f f . Vertebrae
very numerous, 80 to 90. Spines and transverse processes of the
lumbar vertebrae very long and slender ; centra short. Externally,
head with a short but not very distinct beak. Two species,
L. albirostris and L. acutus, are occasionally captured on the British
coasts. Other species occur elsewhere.
Group B. — Head with distinctly elongated rostrum, or beak,
generally marked off from the prenarial adipose elevation by a V-
shaped groove. Rostrum of skull considerably longer than the
cranial portion. Atlas and axis firmly united ; all the other cervical
vertebrae free.
Tf we add to it the above-mentioned genus, Lagemrhywihus, this
group will include all the true Dolphins, Bottle-noses, or, as they
are more commonly called by seafaring people, "Porpoises," which
are found in considerable abundance in all seas, some species being
habitually inhabitants of large rivers, as the Amazon. They are all
among the smaller members of the order, none exceeding 10 feet in
length. Their food is chiefly fish, for the capture of which their
long narrow beaks, armed with numerous sharp-pointed teeth, are
well adapted, but some appear also to devour crustaceans and
molluscs. They are mostly gregarious, and the agility and grace
of their movements in the water are constant themes of admiration
to the spectators of the scene when a " school of Porpoises " is
observed playing round the boWs of a vessel at sea.
1 Gray, Zoology of Erebus and Terror, p. 30 (1846).
- Gray, Proc. Zool. Soc. 1870, p. 77.
3 Gray, Zoology of Erebus and Terror, \>. 35 (1846).
delphinidj: 271
Delphinus. 1 — Teeth very numerous in both jaws, \' ( \ to £#,
occupying nearly the whole length of the rostrum, small, close-set,
conical, pointed, slightly curved. Rostrum elongated, usually about
double the length of the cranial portion of the skull. Pterygoids of
normal form, meeting in the middle line throughout their length.
Palate with deep lateral grooves. Vertebrae 73 to 75. Pectoral fin
of moderate size, narrow, pointed, somewhat falcate. Second and
third digits well developed; the rest rudimental.
The type of the genus is the Common Dolphin of the Mediter-
ranean {!>. delphis, Fig. 97), also found in the Atlantic, and of
Fig. 07. — The Common Dolphin (Delphinus delphis). From Reinhardt.
which a closely allied if not identical form is met with in the
Australian seas (D. forded) and in the North Pacific (D. bairdi).
Other species are D. janira, D. major, etc.
Turd ops.' 2 — Rostrum tapering moderately from base to apex ;
palate not grooved ; symphysis of mandible short ; other cranial
characters as in Delphinus. Teeth |~l to #f, stout (6 to 7 mm. in
antero-posterior diameter). Vertebrae: C 7, D 13, L 17, C 27; total
64. Limbs as in Delphinus. Represented by the widely distributed
T. tursio; T. catalania being a second form. Fossil remains of this
genus from the Italian Pliocene have been recently described.
Prodelphinus. B — Rostrum somewhat variable; mandibular sym-
physis short (less than one -fifth the length of the ramus) ; other
cranial characters as in the preceding genus. Teeth 44} to -f-g,
small, not exceeding 3 mm. in diameter. Vertebras 73 to 78.
Limbs as in Delphinus. Four leading types of this genus are
recognised (all of which have numerous synonyms) viz. P. obscurus,
P. euphrosyne, P. doris, and P. longirostris.
Peron's Dolphin (Delphinus leudorhamphus, Peron, or Leuco-
rhamphus peroni, Lilljeborg) resembles some forms of Prodelphinus in
its cranial characters ; but having no dorsal fin, it has been separated
generically by some writers. It is not improbable that Delphinus
borecdis, Peale, from the Xorth Pacific, in which there is likewise no
dorsal fin, may be an allied form.
Steno. 4 — Rostrum long, narrow, and compressed, very distinct
from the cranium ; mandibular symphysis as long as, or longer than
1 Linn. Syst. Nat. 12th ed. vol. i. p. 108 (1766).
- Gervais, Hist. Xat. des Mammiflres, vol. ii. p. 323 (1855).
3 Gervais, Osteographic des Cetaccs, p. 604 (1880).
4 Gray, Zoology of £ rebus and Terror, p. 43 (1846).
272 CETACEA
one-fourth the length of the ramus ; other cranial characters as in
the preceding genus. Teeth fi to \% of comparatively large size
(5-6 mm. in diameter) ; surface of their crowns finely grooved.
Vertebrae: C 7, D12, L 15, C 32 ; total 66. Represented by
S. rost rati is, from Avhich the forms which have received other names
are probably not specifically separable.
Sotalia. 1 — Pterygoids narrow, not meeting in the middle line,
and in their inner borders diverging posteriorly, instead of being
parallel as in the preceding genera ; other cranial characters much
as in Stem. Teeth tolerably large (4-5 mm. in diameter), f £ to f 4,
with smooth enamelled surface. Vertebra? : C 7, D 12, L 10-14,
C 22 : total 51-55. Pectoral fin broad at base, the breadth being
caused by the considerable development and position of the two
outer digits. Six species are provisionally recognised as distinct,
including the Chinese White Dolphin (S. sinensis) and S. pallidus
from the river Amazon.
Bibliography of Cetacea. — D. F. Eschriclit, U titer suchungcn iiber die Nordischen
WaUthicre, 1849, contains a copious bibliography of the group up to the date of
publication. Since that time numerous monographs on special families and
genera have been published, and a large illustrated general work, Osteographic des
Cetaces, by P. J. Van Beneden and P. Gervais, 1869-80. Besides those already
referred to in the footnotes, the following may be mentioned ; viz. J. F. Brandt,
" Untersuchungen iiber die Fossilen und Subfossilen Cetaceen Europa's," in
Jit oi. de V Acad. Imp. de St. Petersbourg, 7 iime ser. vol. xx. 1873 ; C. M. Scammon,
Murine Mammals of the N. W. Coast of North America, 1874 ; W. H. Flower,
" On the characters and Divisions of the Families of the Delphinidce" Proc. Zool.
Soc. 1SS3, p. 466, and List of the Specimens of Cetacea iii tin- British Museum,
1885 ; F. W.Tnie, " Review of the Family Delphinida;, " Bull. U.S. Nat. Museum,
Xo. 36, 1SS9 ; P. J. A r an Beneden, Histoire Naturclle des Cetacts des Mers
d'Europe, 18S9.
For fossil forms, in addition to the works of Van Beneden, Gervais, and Brandt,
already cited, the reader may refer to various memoirs published by the former
writer in the Bull. Ac. P. Belgique and Ann. Mus. P. Hist. Nat. Brig.
See also R. Lydekker, " The Cetacea of the Suffolk Crag," Quart. Jour a. Oral.
Soc. vol. xlii. p. 7 (1887), and Catalogue of the Fossil Mammalia in the British
Museum, pt. v. (18S7).
1 Gray, Cat. Seals and Whales Brit. Mus. 2d ed. p. 393 (1866).
CHAPTER IX
THE ORDER UNGULATA
Under this term may be included provisionally a large and rather
heterogeneous group of mammals, the existing members of which
form the Pecora and Belluse of Linnaeus, the Ruminantia and
Pachydermata of Cuvier. A few years ago it was found convenient
to restrict the order to a well-marked and distinctly circumscribed
group, comprising the two sections known as Perissodactyla and
Artiodactyla, and to leave out such isolated forms as the Elephant
and Hyrax ; but the discovery of a vast number of extinct species,
which could not be brought under the definition of either perisso-
dactyle or artiodactyle Ungulates, and yet are evidently allied to
both, and to a certain extent bridge over the interval between
these and the isolated groups just mentioned, makes it necessary
either to introduce a number of new and ill-defined ordinal
divisions, or to widen the scope of the original order so as to
embrace them all.
The existing forms are all animals eminently adapted for a
terrestrial life, and in the main for a vegetable diet. Though a
few are more or less omnivorous, and may under some circumstances
kill living creatures smaller and weaker than themselves for food,
none are distinctly and habitually predaceous. Their teeth are
markedly heterodont and diphyodont, — the milk set being well
developed and not completely changed until the animal attains its
full stature. The molars have broad crowns with tuberculated or
ridged surfaces. There are no clavicles. 1 Their toes are provided
with blunt, broad nails, or in the majority of cases with hoofs, more
or less enclosing the ungual phalanges. The scaphoid and lunar
bones of the carpus are always distinct. The humerus has no
entepicondylar foramen. The number of digits varies from five to
one ; and the radius and ulna may be united together.
1 Since this was in type the discovery of transient rudimentary clavicles in
the embryo of the Sheep has been announced by Wincza {Morpholog. Jahrb. xvi.
p. 647).
18
274
UXGULATA
The more generalised of the fossil forms do not conform in all
respects to the above-mentioned characters ; clavicles being present
in Typotheriunt, and perhaps in some of the Condylarthra, while in
the latter group the humerus may have an entepicondylar foramen,
and thus approximate to the corresponding bone of the Carnivora.
Wide as is the gap between existing Carnivores and Ungulates, there
are indeed more or less strongly marked evidences of affinity
between the earlier members of the two orders, as will be again
noticed under the head of the suborder Condylarthra. A departure
from the normal type of foot-structure is exhibited by the extinct
Macivtherium, provisionally included in the Perissodactyla, where
the digits terminated in long and curved claws.
As a general rule, the cheek-teeth have distinct roots, and in
those of the existing suborders a gradual increase in the height of
the crowns of these teeth may be noticed in passing from the more
generalised to the more specialised types. Those teeth in which
the crowns are low, and their whole structure visible from the
grinding surface, are termed brachydont (Fig. 122) ; while those with
higher crowns, in which the bases of the infoldings of enamel are
invisible from the grinding surface, are known as hypsodont (Fig. 1 23).
Again, when the tubercles on the crowns of the molars are more or
less cone-like in form the tooth
is said to be bunodont ; but when
they are expanded in an antero-
posterior direction and curved into
a crescent shape the tooth is
described as selewdont.
The whole order may be
divided into the Ungulata Vera,
containing the suborders Perisso-
dactyla and Artiodactyla, and a
somewhat heterogeneous assem-
blage of animals which may be
called Subungulata or Ungulata
Polydactyla. Cope has pointed
out a character in the structure
of the carpus by which the latter
are differentiated from the former.
Thus in all the Subungulata the
bones of the proximal and distal
row retain the primitive or more
typical relation to each other (see
Fig. 98) ; the os magnum of the
second row articulating mainly
with the lunar of the first, or
with the cuneiform, but not with the scaphoid. But in the group to
Fig. 08
pliant.
Right fore foot of Indian Ele-
x J. U, ulna ; R, radius ; c, cunei-
form ; 1, lunar; sc, scaphoid; u, unciform;
m, magnum ; td, trapezoid ; tm, trapezium ;
I to V, first to fifth digit.
UNGULATA VERA 275
which the vast majority of modern Ungulates belong the second or
distal row has been shifted altogether towards the inner side of the
limb (see Fig. 99), so that the magnum is brought considerably
into relation with the scaphoid, and is entirely removed from the
cuneiform, as in the great majority of existing mammals.
It will be on the whole more convenient to commence our
survey of the members of this suborder with the more specialised
group of the Ungulate Vera, in which the Artiodactyla will be
taken first.
Ungulata Vera. 1
In the typical Ungulata the feet are never plantigrade, and the
functional toes do not exceed four — the inner digit being suppressed,
at all events in all forms which have existed since the Upper
Eocene period.- The os magnum of the carpus articulates freely
with the scaphoid. The allantois is largely developed, and the
placenta, so far as is known, is non-deciduate ; the chorionic villi
being either evenly diffused or collected in groups or cotyledons (in
Pecora). The testes descend into a scrotum. There is never an os
penis. The uterus is bicornuate. The mamma? are usually few
and inguinal, or may be numerous and abdominal (as in Suina), but
are never solely pectoral. The cerebral hemispheres in existing
Ungulates are well convoluted.
The group is now, and has been throughout almost the whole
of the Tertiary period, composed of two perfectly distinct sections,
differing from each other, not only in the obvious characters of the
structure of the limbs, but in so many other parts of their organisa-
tion that they must be considered as of the rank at least of
suborders. The characters of these divisions, first indicated by
Cuvier, were thoroughly established by Owen, by whom the names
whereby they are now generally known were proposed.
Suborder Artiodactyla.
This is a well-defined group, traceable from the Eocene period,
though then apparently by no means so numerous as the Perisso-
dactyles. Some of its types, as that represented in the existing
Swine, have retained to the present time much of the primitive
character of the group ; but others have been gradually becoming
more specialised and perfected in structure, and its latest modifica-
tion, the Cavicorn Ruminants or ]!<>ri<l<c (Antelopes, Sheep, and
Oxen), are now the dominating members of the great Ungulate
order, widespread in geographical range, rich in generic and specific
variation, and numerous in individuals — forming in all these
1 Also known as Diplarthra.
2 The pollex is present in the manus of the extinct Cotylops.
276
UNGULATA
respects a great contrast to such decadent types as those represented
by the Tapirs and Rhinoceroses.
The principal anatomical characters by which the Artiodactyles
are distinguished from the Perissodactyles are as follows. The
premolar and molar teeth usually not alike, the former being
single and the latter two-lobed. The last lower molar of both first
and second dentition almost invariably three-lobed ; and the first
tooth of the upper cheek series always Avithout a milk-predecessor.
Xasal bones not expanded posteriorly. No alisphenoid canal.
W M
B
p IG- 99.— Bones of right forefoot of existing Artiodactyles. A, Pig (Sus scrofa), xj; B,
Red Deer (Cervus elaphus), xi ; C, Camel (Camelus bactrianus), x£. U, Ulna; R, radius; c,
cuneiform; I, lunar; s, scaphoid ; u, unciform ; m, magnum ; td, trapezoid ; tm, trapezium.
From Flower's Osteology of Mammalia.
Dorsal and lumbar vertebras together always nineteen, though the
former may vary from twelve to fifteen. Femur without third
trochanter. Third and fourth digits of both feet almost equally
developed, and their ungual phalanges flattened on their inner or
contiguous surfaces, so that each is not symmetrical in itself, but
when the two are placed together they form a figure symmetrically
disposed to a line drawn between them. Or, in other words, the
;».\is or median line of the whole foot is a line drawn between the
third and fourth digits, Avhile in the Perissodactyles it is a line
drawn down the centre of the third digit. Distal articular surface
ART10DACTYLA 277
of the astragalus divided into two nearly equal facets, one for the
navicular and the other for the cuboid bone. The calcaneum with
an articular facet for the lower end of the fibula. Stomach almost
always more or less complex. Colon convoluted. Caecum small.
Placenta diffused or cotyledonary. Mammae few and inguinal, or
numerous and abdominal.
In treating of many sections of mammals, it is only from the
existing species that our characters and classification can be derived,
and to these chiefly our observations upon the group must be
directed, many of the extinct forms being so little known that they
can only be referred to incidentally. With the Ungulata, however,
it is quite otherwise. The history of the Artiodactyla throughout
the Tertiary period is now well known, and throws great light upon
the position and relations of the existing groups.
The principal modifications which have taken place in the type
from its earliest known and most generalised manifestation have
been the following : —
1. As regards the teeth. Assumption by the grinding surfaces
of the molar teeth either of a bunodont or of a selenodont form.
Modification of the latter from a brachydont to a hypsodont type.
Loss of upper incisors. Development of canines into projecting
tusks. Loss of anterior premolars.
2. As regards the limbs. Eeduction of the ulna from a complete
and distinct bone to a comparatively rudimentary state, in which it
coalesces more or less firmly with the radius. Eeduction of the
fibula till nothing but its lower extremity remains. Reduction
and final loss of external pair of digits (second and fifth), with coal-
escence of the metapodial bones of the two middle digits. Union
of the navicular and cuboid, and sometimes the ectocuneiform,
bones of the tarsus.
3. Change of form of the odontoid process of the axis vertebra
from a cone to a hollow half-cylinder.
4. Development of horns or antlers on the frontal bones, and
gradual complication of form of antlers.
5. By inference only, increasing complication of stomach with
ruminating function superadded. Modification of placenta from
simple diffused to cotyledonary form.
The primitive Artiodactyles, with the typical number (44) of
incisor, canine, and molar teeth, brachydont molars, conical odon-
toid process, four distinct toes on each foot, with metapodium and
all carpal bones distinct, no frontal appendages, and (in all proba-
bility) simple stomach and diffused placenta, were separated at a
very early period into Bunodonts and Selenodonts, although there
is evidence of intermediate forms showing a complete transition
from the one modification to the other. These and other fossil
forms so completely connect the four groups — Suina, Tylopoda,
278 UN GU LATA
Tragulina, and Pecora — into which the existing members of the
suborder have become divided, that in a general classification
embracing both living and extinct forms these divisions cannot be
maintained. In the present work, however, it will be convenient
to retain them, mention being made of some of the chief annectant
forms in separate sections.
SuiNA.
The existing members of this group are characterised by their
bunodont molars, and the absence of a complete fusion of the third
and fourth metapodials to form a "cannon-bone." The full
Eutherian dentition is very frecpiently present.
Remains of very generalised swine -like animals have been
abundantly found in Tertiary formations both in America and
Europe. In the former continent they never (so far as present
evidence indicates) underwent any great diversity of modification,
but gradually dwindled away and almost died out, being only re-
presented in the actual fauna by the two closely allied species of
Peccary, among the smallest and most insignificant members of the
group, which have existed almost unchanged since the Miocene age
at least, if the evidence of teeth alone can be trusted. In the Old
World, on the other hand, the swine have played a more important
part in recent times, having become widely distributed, and throwing
off some curiously specialised forms. At the present time, though
not very numerous in species, they range through the greater part
of the Old World, except within or near the Arctic Circle, although,
in common with all the other members of the great Ungulate order,
they were completely absent from the whole of the Australian region,
until introduced by man in very recent times.
The existing swine-like animals may be divided naturally into
three families: — I. Hippopotamidoi ; II. Suidce, or true Pigs; III.
Dicdtylidce, or Peccaries. 1
Family Hippopotamid^.
Muzzle very broad and rounded. Feet short and broad, having
four subequal toes, Avith short rounded hoofs, all reaching
the ground in walking. Incisors not rooted, but continuously
growing ; those of the upper jaw curved and directed downwards ;
those of the lower straight and procumbent. Canines very large,
curved, continuously growing ; those of the upper jaw directed
downwards. Stomach complex. No caecum.
Hippopotamus. 2 — This genus may be taken to include all the
known members of the family ; it appears to have been always
1 In the table on p. 89 the Peccaries are included in the Suidce.
2 Linn. Syst. Nat. 12th ed. vol. i. V . 101 (1766).
mrropoTAMin.K
279
confined to the Old World. The dentition may be expressed by the
The crowns of the molars (Fig. 100)
formula i
2—3
. « T> P I> m §•
1 4
1_3' > i' P 4'
when worn present trefoil-shaped surfaces of dentine ; and those of
the premolars are sharp. The
facial portion of the skull is much
elongated, the orbits are tubular
and very prominent, and the man-
dible has a large rounded descend-
ing flange at its angle. The cars
are small, the tail is short, and the
legs are likewise so short that the
belly is raised but a little distance
above the ground. The brain is
not richly convoluted, and differs
very considerably from that of
the Pigs, approximating in some
respects to that of the Camel and
Giraffe, but on the whole standing very much by itself. The
stomach of the common species is of enormous dimensions, having
Fig. 100.— Grinding surface of a worn molar
of Hippopotamus amphibius. (From Owen.)
Fig. 101. — The Hippopotamus (Hippopotamus amphibius).
an axial length of 11 feet, and measuring upwards of 15 feet along
the greater curvature. Its axis is longitudinal, the pylorus being-
situated almost in the pelvis, and it is divided into three distinct
compartments, of which the third is cylindrical. The liver of the
adult is of extremely simple form, elongated transversely, and narrow
from above downwards. "With the exception of a few tufts of
28o UNGULATA
hair on the lips, on the sides of the head and neck, and at the
extremity of the short compressed tail, the skin of the hippopotamus,
some portions of which are tAvo inches in thickness, is entirely desti-
tute of covering.
The common Hippopotamus (H. arnphibius), widely distributed
in the rivers and lakes of the African continent, is a huge bulky
animal, characterised by having only two incisors on either side
of each jaw ; the central lower pair being very much larger than the
outer ones. A male from the Upper Nile which lived for nearly
thirty years in the gardens of the Zoological Society of London
measured 1 2 feet along the back from the nose to the root of the tail.
The Hippopotamus lives in herds of from twenty to forty
individuals on the banks and in the beds of rivers, in the neighbour-
hood of which it finds its food. This consists chiefly of grass and
aquatic plants, of which it consumes enormous quantities, the
stomach being capable of containing from 5 to 6 bushels. These
animals feed principally by night, remaining in the water during the
day, although in districts where they are undisturbed by man they
are less exclusively aquatic. In such regions they put their heads
boldly out of the water to blow, but when rendered suspicious by
persecution, they become exceedingly cautious, only exposing their
eyes and nostrils above the water, and even this they prefer
doing amid the shelter of water plants. In spite of their enormous
size and uncouth form, they are expert swimmers and divers, and
can remain under the water from five to eight minutes. They
are said to walk with considerable rapidity on the bottoms of
rivers, beneath at least a foot of water. At nightfall they come
on land to feed ; and when, as often happens on the banks of
the Nile, they reach cultivated ground, they do immense damage
to growing crops, destroying by their ponderous tread even more
than they devour.
A much smaller species, known as the Pigmy Hippopotamus
(H. liberiensis), inhabits some of the rivers of Western Africa, and
is characterised by having only a single pair of lower incisors.
Mainly on this account, it has been proposed to regard this species
as representing a distinct genus, under the name of Ckcerojms ; but
since it agrees so essentially in other characters with the common
form, and sometimes has two incisors on one side of the lower
jaw, it appears preferable to include it in the type genus. The
greater relative size of the brain-cavity as compared with the facial
portion of the skull renders, indeed, the contour of the skull
decidedly different from that of II. amphibius ; but this is a feature
generally found in young individuals of larger species, and also in
the adults of allied smaller forms.
Both the existing species are now exclusively confined to Africa,
but in the Pleistocene and Pliocene periods the genus was widely
SUID.K 281
spread over the Old World. Thus in the Upper Pliocene of the
Continent and the Pleistocene of England we meet with remains of
a very large fossil Hippopotamus which cannot be specifically
distinguished from 77. amphiMus. In the Pleistocene and Pliocene of
India there are two species having three pairs of incisors in both
jaws. Of these H. palceindicm has the second pair in the lower jaw
very minute, and evidently just about to disappear; from which Ave
learn that it is this pair which is missing in H. amphibius. In the
still more generalised 11. sivalensis the three incisors in the
lower jaw are of equal size. Hexaprotodont species also occur
in the Upper Tertiaries of Burma and Algeria. Small tetra-
protodont species (H. penttandi and H. minutus) have left their
remains in enormous quantities in the caves and fissures of Sicily
and Malta.
Family Suid.e.
An elongated mobile snout, with an expanded, truncated, nearly
naked, flat, oval terminal surface in which the nostrils are placed.
Feet narrow ; four completely developed toes on each. Hoofs of
the two middle toes with their contiguous surfaces flattened. The
outer (second and fifth) digits of existing forms not reaching to
the ground in the ordinary walking position. Teeth variable in
number, owing to the suppression in some forms of an upper incisor
and one or more premolars. Incisors rooted. Upper canines
curving more or less outwards or upwards. Stomach simple,
except for a more or less developed pouch near the cardiac orifice.
A caecum. Colon spirally coiled. Confined to the Old World.
The mandible has no descending flange at the angle. The
crowns of the molars do not wear into such distinct trefoils as in
the Hippopotamus, and are oblong
in shape. The last molar of both
the upper and loAver jaw (Fig. 102)
has an additional hinder lobe or
talon, varying in size in the different
species. The upper premolars are
simpler than the true molars. Fig. 102.— Grinding surface of a worn
SuS. 1 Dentition : i 4 , C \, p £, m third ri 8 h t lower molar of the Wild Boar
o i 1 i tt • • v (Sus scrofa). After Owen.
-§-; total 44. Upper incisors dimin-
ishing rapidly in size from the first to the third. Lower incisors
long, narrow, closely approximated, and almost horizontal in position,
their apices inclining towards the middle line ; the second slightly
larger than the first, the third much smaller. Canines strongly
developed and with persistent roots and partial enamel -covering,
those of the upper jaw not having the usual downward direction,
1 Linn. Syst. Nat. 12tli ed. vol. i. p. 102 (1766).
282 UN GU LATA
but curving strongly outwards, upwards, and finally inwards, while
those of the lower jaAv are directed upwards and outwards with
a gentle backward curve, their hinder edges working and wearing
against the front edges of the upper canines. 1 They appear
externally to the mouth as tusks, the form of the upper lip being
modified to allow of their protrusion, but are much less developed
in the females than in the males. The teeth of the molar series
gradually increase in size and complexity from first to last, and
are arranged in contiguous series, except that the first lower
premolar is separated by an interval from the second. First and
second upper premolars with compressed crowns and two roots.
The third and fourth have an inner lobe developed on the crown,
and an additional pair of roots. The first and second true molars
have quadrate crowns, with four principal obtuse conical cusps,
around which numerous accessory cusps are clustered. The length
of the third molar is nearly ecpial (antero-posteriorly) to that of
the first and second together, its crown having, in addition to the
four principal cusps, a large posterior talon or heel, composed of
numerous clustered conical cusps, and supported by several additional
roots. The lower molar teeth resemble generally those of the upper
jaw, but are narrower. Milk dentition : i%,c^,m§', total 28, —
the first permanent premolar having no predecessor in this series.
The third incisor, in both upper and lower jaws, is large, developed
before the others, and has much the size, form, and direction of
the canine. Vertebrae : C 7, D 1 3-1 4, L 6, S 4, C 20-24. The hairy
covering of the body varies much under different conditions of
climate, but when best developed, as in the European Wild Boar,
consists of long stiff bristles, mostly abundant on the back and
sides, and of a close softer curling under-coat.
The skull of the Pigs (Figs. 103-105) has the axis of the face
bent down upon the basicranial axis, as is also the case with the
Sheep. Its most striking feature is the elevation and backward
slope of the occipital crest formed by the union of the supraoccipital
and parietals. The broad and flat frontals have small postorbital
processes, which do not join the zygomata, so that the orbits are
open behind. The nasals are very long and narrow ; and the pre-
maxillse send up long nasal processes, stopping short of the frontals.
A peculiar prenasal bone is developed at the anterior extremity of
the mesethmoid, which serves to strengthen the cartilaginous snout.
The palate is long and narrow, and extends behind the last molar
1 If from any accidental circumstances these teeth are not constantly worn
down by friction, they grow into a complete circle, the point penetrating the
bone of the jaw close to the root of the tooth. The natives of the Fiji Islands
avail themselves of this circumstance to produce one of their most valued orna-
ments — a circular boar's tusk: the upper canines being extracted, the lower ones
are allowed to grow to the desired form.
sum.?:
:§3
tooth. In most species the occipital crest is more nearly vertical
than in the skull represented in Fig. 104.
This genus occurs at present under three principal modifications
or subgenera.
J. — Sus proper comprises a number of animals
found in a wild state throughout the greater part
of Europe (except where extermin-
ated hv human airencv), the north
of Africa, southern continental
Asia, and the
meat islands of
the Malayan
archipelago,
Formosa, and
Japan. The fol-
lowing among
others have
been admitted
by many zo-
ologists as dis-
tinct species :
SUS SCTOfa, Fig. 103.— Left lateral view of the dentition of the Boar(Sws sero/a),
the Wild Boar tlie roots of the teeth being exposed by removing the external lamina
i ti » • of bone.
01 Europe, Asia
Minor, and North Africa, once common throughout the British
Isles; S. sennaarensis, North-East Africa; S. cristatus, India; S.
. [04.— Left lateral view of the skull of Sus longirostris. \ natural size. (From Nehring.)
vittatus, Java, Borneo, Amboyna, Batchian ; S. papuensis, New
Guinea; 8. timorensis, Timor and Rotti ; S. andamanensis, Anda-
2S4
UNGULATA
man Islands ; S. taevanus, Formosa ; S. leucoimjstax,
verrucosus, Java, Borneo,
Celebes, Philippines, and
Java. The last four
Japan ; S.
Ceram ; S. barbatus, Borneo ; S. celebensis,
Moluccas ; S. hngirostris, Borneo and
species form an allied group in which the
facial portion of the skull may be greatly
elongated ; S. barbatus and & celebensis
being characterised by the small size and
simple structure of the talon of the third
molars. The skull of S. hngirostris is
shown in Figs. 104 and 105. The small
8. andamanensis also has very simple third
molars. S. vittatus, S. leucomystax, S. cris-
tatus, S. taevanus, and S. papuensis form
another group, in which the third molar
is generally of very complex structure,
more or less closely allied to the Wild
Boar ; and Dr. Nehring is inclined to
think that the Avhole five might be in-
cluded under a single specific name. This
list will give some idea of the geographical
distribution of wild Pigs, but it must be
borne in mind that through the whole of
this region, and in fact now throughout
the greater part of the habitable world,
Pigs are kept by man in a domesticated
state, and it is still an open question
whether some of the wild Pigs of the
islands named above may not be local
races derived originally from, or crossed
with, imported domestic specimens. In
New Zealand a wild or rather " feral "
race is already established, the origin of
which is of course quite recent, since it is
well ascertained that no animal of the
kind ever lived upon the island until
after its settlement b}^ Europeans.
Whether the various breeds of domestic Pms have been derived
from one or several sources is still unknown. As in so many
similar cases, there is no historic evidence upon the subject,
and the researches of naturalists, as Nathusius, Biitimeyer,
Bolleston, Nehring, and others, who have endeavoured to settle
the question on anatomical evidence, have not led to any satis-
factory conclusions. It is, however, tolerably certain that all
the species or forms of wild Pigs enumerated above and all the
domestic races are closely allied, and it is probable (though of
this there has been no opportunity of proof) will breed freely
Fig. 105. — Frontal aspect of
the cranium of Sits longirostris.
I; natural size. (From Nehring.)
.s7 •//>./•;
285
together. It is a curious circumstance that the young of all
the wild kinds of Pigs (so far as yet is known) present a
uniform coloration, being dark brown Avith longitudinal stripes of
a paler colour, a character which completely disappears after the
first few months. On the other hand, this peculiar marking is
rarely seen in domestic Pigs in any part of the world, although it
has been occasionally observed. It is stated by Darwin that the
Pies which have run wild in Jamaica and the semiferal Pigs of New
(iranada have resumed this aboriginal character, and produce longi-
tudinally striped young ; these must of course be the descendants
of domestic animals introduced from Europe since the Spanish
Fig. 106.— Wild Boar and Young.
conquest, as before that time there were no true Pigs in the New
World. Another character by which the European domestic Pig
differs from any of the wild species is the concave outline of the
frontal region of the skull, a form still retained by the feral Pigs
in New Zealand.
B. — The diminutive Pig of the Nipal, Terai, and Bhutan, Sus
salvanius, has been separated from the rest by Hodgson under the
generic name of Porcula, but all the alleged distinctive characters
prove on more careful investigation to have little real value. Owing
to its retired habits and power of concealment under bushes and
long grass in the depths of the great Sal Forest, which is its
principal home, very little has been known of this curious little
animal, scarcely larger than a hare. The acquisition of living
>S6
UXGULATA
specimens in the London Zoological Gardens has, however, afforded
opportunities for careful anatomical observation. 1
C. — Two well-marked species of African Swine have been with
more reason separated under the name of Potamochcerus. The denti-
tion differs from that of the true Sus, inasmuch as the anterior
premolars have a tendency to disappear ; sometimes in adult
specimens the first upper premolar is retained, but it is usually
absent, as well as the first and often the second lower premolars.
The molar teeth are also less complex ; the last especially having a
Fig. 107. — The Red River-Hog (Sun porous). From Sclater, GuicL to Animals
in Zoological Society's Gardens, 1883, p. 183.
much less developed talon. There are likewise characteristic cranial
differences. The two species are very distinct in outward appearance
and coloration. One is S. afrkanus, the South African River-Hog,
or Bosch- Vark, of a gray colour, and the other S. porous, the West
African Red River-Hog (Fig. 107), remarkable for its vivid colouring
and long pencilled ears. It should be noted that the young of both
these species, as well as of the pigmy S. sahanv&s, present the striped
character of the true Sus, a strong indication of close affinities,
whereas in all the following forms this is absent.
The genus Sus, in the above extended sense, is well represented
in the Tertiaries of the Old World from the period of the Lower
Pliocene upwards. In the Pliocene and Pleistocene of India
1 See Garson, Proc. Zool. Soc. Land. 1883, p. 413.
sr/n.r. 287
S. falcon&ri and S. karnuliensis are characterised by the extremely
complex structure of the molars, in which they show decided signs
of approximation to the Wart-Hogs ; the same feature being
exhibited by S. phacoclia miili s of the Algerian Pliocene. S. titan
and S. giganteus, of the Indian Pliocene, together with S. antiguus
and S. erymanthius, of the corresponding European deposits, are very
large species characterised by their comparatively simple molars;
S. titan being fully as large as a Tapir. S. hysudricus of the Pliocene
of India, and S. palceochoerus of that of Europe, are smaller allied
species not improbably related to 8. andamanensis, with which they
agree in molar structure. S. anernensis, of the Upper Pliocene
of France, appears to be allied to S. africanus ; while in the
diminutive S. punjaMensis of the Pliocene of North- Western India
we probably have the direct ancestor of S. salvanius.
Fig. 10S. — Head of Babirusa (Babirusa aljurus).
Babirusa} — Dentition: i f, c \, p f , m % ; total 34. The total
number of teeth is therefore considerably reduced, the outer upper
incisor and the two anterior premolars of both jaws being absent.
The molars, especially the last, are smaller and simpler than in Sus;
but the great peculiarity of this genus is the extraordinary develop-
ment of the canines of the male. These teeth (Fig. 108) are
ever-growing, long, slender, and curved, and entirely without enamel
covering. Those of the upper jaw are directed upwards from their
base, so that they never enter the mouth, but piercing the skin of
the face, resemble horns rather than teeth, and curve backwards,
downwards, and finally often forwards again, almost or quite
touching the skin of the forehead. Vertebrae: C 7, D 13, L 16,
S 4. There is but one species (B. alfurus), found only in the
islands of Celebes and Buru. Its external surface is almost
1 Lesson, Man. d. Mamm., p. 337 (1827), " Babirusa. "
288 UNGULATA
entirely devoid of hair. "With regard to the curiously modified
dentition, Wallace {Malay Archipelago, vol. i. p. 435) makes the
followins; observations: — "It is difficult to understand what can
be the use of these horn-like teeth. Some of the old writers
supposed that they served as hooks by which the creature could
rest its head on a branch. But the way in which they usually
diverge just over and in front of the eye has suggested the more
probable idea, that they serve to guard these organs from thorns
and spines while hunting for fallen fruits among the tangled thickets
of rattans and other spiny plants. Even this, however, is not
satisfactory, for the female, who must seek her food in the same
way, does not possess them. I should be inclined to believe
rather that these tusks Avere once useful, and were then worn
down as fast as they grew, but that changed conditions of life have
rendered them unnecessary, and they now develop into a monstrous
form, just as the incisors of the Beaver and Kabbit will go on
growing if the opposite teeth do not wear them away. In old
animals they reach an enormous size, and are generally broken off
as if by fighting."
Phacochoerus. 1 — The Wart- Hogs, so called from the large
cutaneous lobes projecting from each side of the face, have
the teeth still more remarkably modified than in Bahirusa.
The milk -dentition, and even the early condition of the per-
manent dentition, is formed on the same general type as that
of Sus, except that certain of the typical teeth are absent, the
formula being i\ 3 c ^, p %, m f, total 34 ; but as age advances all
the teeth have a tendency to disappear, except the canines and the
posterior molars, which in some cases are the only teeth left in
the jaws, and attain an extraordinary development. The upper
canines especially are of great size, and curve outwards, forwards,
and upwards. Their enamel covering is confined to the apex, and
soon wears away. The lower canines are much more slender, but
follow the same curve ; except on the posterior surface, their crowns
are covered with enamel. Unlike those of the Babirusa, the canines
of the Wart-Hog are large in both sexes. The third molar tooth of
both jaws is of great size, and presents a structure at first sight
unlike that of any other mammal, being composed of numerous
(22-25) parallel cylinders or columns, each with pulp-cavity, dentine,
and enamel covering, and packed together with cement. Careful
examination will, however, show that a similar modification to that
which has transformed the comparatively simple molar tooth of
the Mastodon into the extremely complex grinder of the Indian
Elephant has served to change the tooth of the common Pig into
that of Phacochoerus ; and, as already mentioned, some of the fossil
Indian and African species of Sus indicate the mode in which this
1 Cuvier, Mgne-Anitnal, vol. i. p. 236 (1817).
DICOTYLID^E 289
transition came about. The tubercles which cluster over the surface
of the crown of the molars of the common Pig are elongated and
drawn out into columns in the "Wart-Hog, as the low transverse
ridges of the Mastodon's tooth become the leaf-like plates of the
Elephant's.
Two species of this genus are commonly but rather doubtfully
distinguished : — /'. africanus, ^Elian's Wart-Hog, widely distributed
over the continent; and /'. cetkiopicus, Pallas's Wait-Hog, confined
to South-Eastern Africa. In specimens attributed to the latter
species the dentition reaches its most complete reduction, as in
adult animals the upper incisors are absent and the lower ones worn
down to the roots.
Ft I ill ill/ DlCOTYLID.E.
Snout as in Swidce. Dentition: i §, c ~, /> J-, m § ; total 38.
Incisors rooted ; upper canines directed downwards, with sharp
cutting hinder edges. Toes, four on the fore feet and three on the
hind feet (the fifth wanting). Stomach complex. A caecum.
Confined to the New World.
Dicotyles. 1 — The teeth of the Peccaries (Dicotylcs) differ from those
of the true Pigs (Sus) numerically in wanting the upper outer
incisor and the anterior premolar on either side of each jaw, and also
in the circumstance that the last premolar is nearly as complex as
the molars. The upper canines have their points directed down-
wards, not outwards or upwards as in the Boars, and are very
sharp, with cutting hinder edges, and completely covered with
enamel until worn. The lower canines are large, directed up-
wards and outwards, and slightly curved backwards. The pre-
molar and molar teeth form a continuous series, gradually increasing
in size from the first to the last. The true molars have square
quadricuspidate crowns. The stomach is much more complex than
in the true Pigs, almost approaching that of the ruminants. In the
feet the two middle (third and fourth) metapodial bones, which are
completely separate in the Pigs, are united at their upper ends, as
in the ruminants. On the fore foot the two (second and fifth) outer
toes are equally developed as in Pigs, but on the hind foot, although
the inner (or second) is present, the outer (or fifth) toe is entirely
wanting, giving an unsymmetrical appearance of the member, very
unusual in Artiodactyles. Vertebrae: C 7, D 14, L 5, S 4, C 7.
As in the Pigs, the snout is truncated, and tlie nostrils are situated
in its flat, expanded, disc-like termination. The ears are rather
small, ovate, and erect ; and there is no external appearance of a
tail. The surface of the body is well covered w T ith thick bristly
hair, and rather behind the middle of the back is a large and
1 Cuvier, Regne Animal, vol. i. p. 237 (1817).
19
290
UNGULATA
peculiar gland, which secretes an oleaginous substance with a power-
ful musky odour. This was mistaken by the old travellers for a
second navel, a popular error which suggested to Cuvier the name
of Dicotyles. "When the animal is killed for food, it is necessary
speedily to remove this gland, otherwise it will taint the whole
flesh so as to render it uneatable.
There are two species, 1 so nearly allied that they will breed
together freely in captivity. Unlike the true Pigs, they never
appear to produce more than two young ones at a birth. The
Collared Peccary (D. tajacu, Linn., torquatus, Cuvier), Fig. 109, ranges
from the Red River of Arkansas through the forest districts of
Fig. 109. — The Collared Peccary (Dicotyles tajacu).
Central and South America as far as the Rio Negro of Patagonia.
Generally it is found singly or in pairs, or at most in small herds of
from eight to ten, and is a comparatively harmless creature, not being
inclined to attack other animals or human beings. Its colour is dark
gray, with a white or whitish band passing across the chest from
shoulder to shoulder. The length of the head and body is about
36 inches. The White-lipped Peccary or Warree (D. labiatus, Cuvier)
is rather larger, being about 40 inches in length, of a blackish
colour, with the lips and lower jaw white. Its range is less ex-
tensive, since it is not found farther north than British Honduras
or south of Paraguay. It is generally met with in large herds of
from fifty to a hundred or more individuals, and is of a more
pugnacious disposition than the former species, and capable of
1 Professor Cope considers that there is a third species, for which he has pro-
posed the name D. angularis.
DICOTYLin.K 291
inflicting severe wounds with its sharp tusks. A hunter who en-
counters a herd of them in a forest has often to climb a tree as
his only chance of safety. Both species are omnivorous, living on
roots, fallen fruits, worms, and carrion; and when they approach
the neighbourhood of villages and cultivated lands they often
inflicl great devastation upon the crops of the inhabitants.
Remains of the two existing species of Peccary, as well as of one
much larger extinct form, are found in the cavern-deposits of Brazil ;
while la rue Peccaries also occur in the Pleistocene of the United
States, which, although they have been referred to a distinct genus,
Platygonus, on account of their relatively smaller incisors and some-
what simpler premolars, may well lie included in Bicotijles.
Allied Extinct Genera. — In the Tertiary deposits of both
the Old and New World occur remains of Pig -like animals
which, so far as we can judge, appear to connect the Peccaries
so closely with the true Pigs as to render the Dicotylidm
really inseparable from the Sui<?<> . Of these the American
genus Chcenohyus has the lower canine with a triangular cross
section and received into a notch in the upper jaw, as in the Pec-
caries, but the fourth upper premolar is simpler than the molars, as
in the under-mentioned genus Hyotherium. The typical forms have
only three premolars, but in others, which it has been proposed to
separate generically as Bothrioldbis, there are four of these teeth.
Hyotherium, of the Pliocene
and Miocene of the Old
"World, is a generalised
form allied both to Sus and
Dicotyles as well as to certain
extinct genera. The upper
molars (Fig. 110) are char-
acterised by their square
crowns the last havin°' no FlG - HO.— The 1 three left upper molars of Hyotlm
, . . 1 ■ t i 1 i & verimense, from the Pliocene of India.
distinct third lobe, and com-
ing into use before the first is much worn, while the last premolar is
simpler than the true molars. The canines, which have an oval section
and are scarcely larger than the incisors, are not received into a
notch in the upper jaw. In the Pliocene of India there occurs an
apparently allied genus known as Hippohyus, in which the crowns
of "the molars are much taller, and have lateral infoldings of the
enamel, producing a very complex pattern on the worn crowns.
The European Miocene genus Listriodm, with the dental formula
i | } c i j, |, m I, differs from all the preceding in having the
anterior and posterior pairs of tubercles of the molars united into
ridges running across their crowns, so that these teeth resemble the
lower molars of the Tapir. The genus is also found in the Lower
Pliocene of India.
292
UNGULATA
Extinct Transitional Artiodactyles.
In this place it will be convenient to notice briefly a few of
the extinct types of Tertiary Artiodactyles which connect the
existing bunodont Suina with the more specialised selenodont
croups mentioned below so closely as to show that in a strictly
palajontological classification such groups cannot be maintained.
It should be mentioned that while some of these extinct forms
were in all probability actual ancestral links between the bun-
odonts and selenodonts, others, like the Anoplotheres, died out
entirely without giving rise to any more specialised descendants.
Chceropotamidce. — In this family the molars are intermediate in
structure between those of the Suidce and the next family. The
upper ones have very broad crowns, with the five columns arranged
as in Anthracotherium ; while the premolars are not secant, and may
be very large. The best known forms are the small Cebochcerus of
the Phosphorites of Central France ; Chwrojiotamus of the Upper
Eocene, the type species of which was of the size of a large Pig,
with the dental formula i
3.
3»
hP
3>
III
3J
and no distinctly
selenodont structure in the molars ; the much larger Elotherivm,
from the Upper Eocene and Lower Miocene of both the Old and New
Worlds, which presents the very rare feature of the absence of a third
lobe to the last lower molar ; and the equally large Tetraconodou of
the Pliocene of India, in which this third lobe was present and the
premolars were of enormous size. The remarkable North American
Eocene genus Achcenodon should perhaps also be placed here.
Anthracotheriidce. — The genera Anthracotherium and Hyopotamus,
of the upper Eocene and Miocene,
have the typical Eutherian dental for-
mula ; the upper molars (Fig. Ill)
carrying three columns on the anterior
and two on the posterior half of the
crown, all of which are of a more or
less decidedly selenodont structure.
The mandible has a descending flange
at the angle. The figured tooth (in
which the antero-internal and antero-
median columns are imperfect) may be
compared with the diagram given in
Fig. 5, p. 32, when the homology of
uperfect third left the columns or tubercles will be at
upper molar of Hyopotamus glganteus, once apparent, the broken ailterO-
Miocene, India. (From the Paiwonto- mec ]i an co lumn representing the proto-
logia Indica.) . „ - 1 I , . .
conule. Some 01 the species are of
large size, while others are comparatively small.
EXTLXCT FAMILIES
y -93
Fro. 112.— A right
upper molar of Mi ry-
copotam " i pusillus,
Pliocene, India.
(From the Palceonto-
logia Indica.)
and the feet have four digits.
M< ri/mjiolininis. — The genus Mrryrojtotnmusoi the lower Pliocene
of India may he regarded as an Anthraeotheroid which has lost
the antero-median column to the upper molars
(Fig. 11-). so that these teeth are consequently
quadrituberculate ; and may thus he regarded as
typical examples of the hrachy-selenodont modifica-
tion of molar structure.
Cotylopidce. — The Miocene genus Cot)jl<>p* (Ore-
oihm l ) is the type of a large American family in
which the upper molars are selenodont and usually
have four columns, while the lower canine is approxi-
mated to the incisors and its form and function
assumed by the first premolar. The last upper
premolar is simpler than the molars. There is no
flange to the angle of the mandible ;
The affinities of this peculiar family are probably widely spread,
but they may have been derived from the Anthracotheriidce. The
type genus has the full Eutherian dentition, but in some of the
more specialised forms (Cyclopidius) the upper incisors may be
wanting, and large vacuities occur in the lachrymal region. The
generalised genus Protoreodon, of the Upper or Uinta Eocene, has
rive cusps on the upper molars, arranged as in the Anthracotheriida .
The pollex is retained in the manus of the t}-pe genus.
The family may be divided into subfamilies as follows : —
I. Upper molars with four columns.
1. Orbits open, no lachrymal fossa, a diastema, the last upper
premolar with two outer columns, outer wall of upper
molars concave and inclined inwards. — Agriochosrince
(Agriochosrus).
2. Orbits closed, a lachrymal fossa, no diastema, the last upper
premolar with one outer column ; outer wall of upper
molars flattened. — Cotylopince (Cotylops, Eporeodon, Mery-
cochcerus, Cyclopidius, etc.)
II. Upper molars with five columns. — Protoreontince (Protoreodon).
Anoplotheriidce.
— This family in-
cludes several
Upper Eocene
European genera,
with selenodont
upper molars,
carrying five
columns arranged
as in Anthraco-
theriwm. One of
Fie. 113. — Restoration of Anoplotherium con
(Upper Eocene). Cuvier.
This name (Leidy, 1851) is preoccupied by Orodus (Agassiz, 1838).
294 UNGULATA
the earliest known, Anoplotherwm, was fully described by Cuvier
from remains found in the Paris gypsum-beds (Upper Eocene).
Its forty-four teeth formed a series unbroken by a gap or diastema,
and were of uniform height (as in Man alone of existing mam-
mals). Its tail was long, with large chevron bones underneath,
not usually found in Ungulates, and there were either three or
two toes on each foot. It was in many respects a much-
specialised form, apparently not on the line of descent of any of
the existing groups.
Dacrytherium is an allied genus whose dentition leads on to that
of the smaller Xiphodon. The latter genus is characterised by the
compressed and elongated form of the crowns of the first three
premolars, which thus approximate to those of the Chevrotains.
There were only two functional digits to the feet. The so-called
Hyopotamus picteti, of the Swiss Eocene, is a species of Dacrytherium.
Cccnotheriidce. — The typical representatives of this family are
small animals not larger than the Chevrotains, with the full comple-
ment of teeth, generally no marked gap in the series, and the
crowns of the upper molars carrying two columns on the anterior
and three on the posterior half of the crown — precisely the reverse
of the arrangement obtaining in the Anthracotheriidie. The known
forms are from the Upper Eocene and Lower Miocene of Europe.
In Cc¬herium the molars are selenodont, while they are bunodont
in Dichobunus. Homacodon, of the Bridger Eocene of the United
States, is closely allied to the the latter. The first lower premolar
of Dichobumis assumes the form and function of a canine. Spanio-
therium (Metriotherium) is a much larger form, in which the molars
are not unlike those of Anthracotherium, if the arrangement of the
cusps were reversed ; it occurs in the Eocene Phosphorites of
France. It is suggested that the Tylopoda may have originated
from this group.
Tapirulus is a small Eocene Artiodactyle with the columns of
the upper molars, which are somewhat like those of Hyopotamus,
tending to form transverse ridges ; its family position is uncertain.
Dichodontidce. — The European genera included in this family all
have quadritubercular selenodont molars, and show signs of approxi-
mating more or less closely to existing types. Dichodon, from the
Upper Eocene and Lower Miocene, has the full complement of teeth,
which show no diastema, and have low crowns. The fourth upper
premolar has four columns, like the true molars, and the corre-
sponding lower tooth three complete lobes ; these features being
unknown in any other Selenodonts. In Lophiom&ryx, of the same
beds, the somewhat higher crowns of the molars approximate to
those of the Cervida:, but the hinder lobes of the upper ones are
imperfectly developed ; the genus may be allied to the Tragulidce.
In the small Gclocus, of the Lower Miocene, the molars are not
CAMELIDjE 295
unlike those of Dichodon; but the navicular and cuboid bones of
the tarsus were fused together, and the metatarsals had united to
form a "cannon-bone," although the metacarpals still remained
distinct. It is not improbable that upper incisors were wanting ;
and it has been suggested that we have in this genus the ancestral
type of the Tragrdidos and Cervidce.
Tylopoda.
Family Camelid.e.
This group is represented at the present day by the two species
of Camels of the Old World and the Llamas of South America,
collectively constituting the family Camelidce. The special characters
which the Llamas and Camels have in common, and the combina-
tion of which distinguishes them from the rest of the Artiodactyles,
are as follows. The premaxilla? have the full number of incisor
teeth in the young state, and the outermost is persistent through
life as an isolated laniariform tooth. The canines are present in
both jaws, and those of the mandible are differentiated from the
long, procumbent, and spatulate incisors, being suberectand pointed.
The crowns of the true molars belong to the crescentic or selen-
odont type, and are very hypsodont ; but one or more of the
anterior premolars is usually detached from the series, and is
of simple pointed form. The auditory bulla is filled with cancellous
tissue. The hinder part of the body is much contracted, and the
femur long and vertically placed, so that the knee-joint is lower
in position, and the thigh altogether more detached from the
abdomen than in most quadrupedal mammals. The limbs are
long, but with only the third and fourth digits developed ; no
traces of any of the others being present. The trapezoid and mag-
num of the carpus, and the cuboid and navicular of the tarsus are
distinct. The two metapodial bones of each limb are confluent for
the greater part of their length, though separated for a considerable
distance at the lower end. Their distal articular surfaces, instead
of being pulley-like, with deep ridges and grooves, as in other recent
Artiodactyles, are simple, rounded, and smooth. The proximal
phalanges are expanded at their distal ends, and the wide, depressed
middle phalanges are embedded in a broad cutaneous pad, forming
the sole of the foot, on which the animal rests in walking, instead
of on the hoofs. The ungual phalanges are very small and nodular,
not flattened on their inner or opposed surfaces, and not completely
encased in hoofs, but bearing nails on their upper surface only.
The cervical region is long and flexuous, and the vertebrae of which
it is composed are remarkable for the position of the canal for
296 UNGULATA
the transmission of the vertebral artery, which does not perforate
the transverse process, but passes obliquely through the anterior
part of the pedicle of the arch (a condition only found in two other
genera of mammals, Macrauchenia and Myrmecophaga). There are
no horns or antlers. Though these animals ruminate, the stomach
differs considerably in the details of its construction from that of
the Pecora. The interior of the rumen or paunch has no villi on
its surface, and there is no distinct psalterium or maniplies. Both
the first and second compartments are remarkable for the presence
of a number of pouches or cells in their walls, with muscular septa,
and a sphincter-like arrangement of their orifices, by which they can
be shut off from the rest of the cavity, and into which the fluid
portion only of the contents of the stomach is allowed to enter. 1
The placenta is diffuse, as in the Suina and Tragulina, not coty-
ledonary, as in the Pecora. Finally, the Camelidce differ not only
from other Ungulates, but from all other mammals, in the fact
that the red corpuscles of the blood, instead of being circular in
outline, are oval, as in the inferior vertebrated classes.
Camelusr — Dentition of adult : i ^, c ^, p %, m % ; total 34. First
upper premolar simple, placed immediately behind the premaxilla?,
and separated by a long diastema from the penultimate tooth of
that series. Lower incisors somewhat proclivous, the outermost the
largest. Skull elongated, with an overhanging occiput, orbits com-
pletely surrounded by bone, and the premaxillte not articulating
with the arched and somewhat elongated nasals. Vertebra? : C 7,
I) 12, L 7, S 4, C 13-15. Ears comparatively short and rounded.
One or two dorsal adipose humps. Feet broad, with the toes very
imperfectly separated. Tail well developed, tufted at the end.
Hair nearly straight, and not woolly. Size very large and bulky.
The genus is now represented by two species, viz. the single-
humped Arabian Camel (Camelus dromedarius), and the double-
humped Bactrian Camel (C. hactrianus, Fig. 114). 3 The former
1 The stomach of the Camel inhabiting the Arabian desert is commonly
looked upon as a striking example of specialised structure, adapted or modified
in direct accordance -with a highly specialised mode of life ; it is therefore very
remarkable to find an organ exactly similar, except in some unessential details,
in the Llamas of the Peruvian Andes and the Guanacos of the Pampas. No
hypothesis except that of a common origin will satisfactorily account for this,
and, granting that this view is correct, it becomes extremely interesting to
find for how long a time two genera may be isolated and yet retain such close
similarities in parts which in other groups appear readily subject to adaptive
modifications.
2 Linn. Syst. Nat. 12th ed. vol. i. p. 90 (1766).
3 There is much confusion as to the proper use of the names Camel and
Dromedary. It is now generally accepted that the former is the common term
for all the members of the genus, and that Dromedary should be confined to the
lighter and swifter breeds of the one-humped species. One of the oldest pictures of
CAMELID.K 297
is quite unknown in a wild state, but it is reported that wild
Bactrian Camels occur in the more remote parts of Turkestan. The
latter species is found in a domesticated state throughout a large
portion of Turkestan and the neighbouring region, extending as far
as the Crimea in the west and to Lake Baikal and Pekin in the
east. It is a heavier and more clumsy animal than the Arabian
Camel, with thicker hair, shorter legs, and the feet more callous
and better adapted to a hard ground. The hair is most developed
upon the top of the head, neck, humps, arm, and wrist. Bactrian
Camels are occasionally brought over the stupendous mountain
--<---.■...'
Fig. 114. — The Bactrian Camel (Camelusjbactriarvus).
passes south of Yarkand to within a few days' journey of Leh, in
Kashmir territory.
The Arabian Camel is commonly employed as a beast of burden
in Africa and India, and has of late years been introduced into
Australia for the same purpose ; it is especially valuable in crossing
long stretches of arid desert from its power of existing for a con-
siderable period of time without water. The female goes fully
eleven months with young, and produces but a single calf at a
birth, which is suckled for a whole year. In disposition the Camel
is surly and subject to furious outbursts of temper, especially during
the rutting season. At such periods the male utters a peculiar and
highly disagreeable bubbling noise in its throat, Avell known to all
who have travelled in India with Camels as their transport. It has
been said that the Camel is docile, but Palgrave observes : —
the two-humped Camel extant, painted on the wall of the Chapter House of
"Westminster Abbey, has, however, "Dromedary" inscribed under it.
298 UNGULATA
" If docile means stupid, well and good; in such a case the Camel is
the very model of docility. But if the epithet is intended to designate
an animal that takes an interest in its rider so far as a beast can, that
in some way understands his intentions, or shares them in a sub-
ordinate fashion, that obeys from a sort of submissive or half-fellow-
feeling with his master, like the horse or elephant, then I say that
the camel is by no means docile — very much the contrary. He
takes no heed of his rider, pays no attention whether he be on his
back or not, walks straight on when once set agoing, merely
because he is too stupid to turn aside, and then should some
tempting thorn or green branch allure him out of the path, continues
to walk on in the new direction simply because he is too dull to turn
back into the right road. In a word, he is from first to last an
undomesticated and savage animal, rendered serviceable by stupidity
alone, without much skill on his master's part, or any co-operation
on his own save that of an extreme passiveness. Neither attach-
ment nor even habit impress him ; never tame, though not wide-
awake enough to be exactly wild." The two species breed together
freely, and among the Yourouks of Asia Minor, hybrids, or mules,
the produce generally of a male Bactrian and a female Arabian
camel are preferred to either of the pure breeds.
Fossil remains of Camels are found in the Pliocene of the
Siwalik Hills in Northern India. These differ from the existing
representatives of the genus in having a vertical ridge at the
antero-external angle of the lower molars, whereby they resemble
Auchenia ; their cervical vertebras are also intermediate in structure
between those of the latter and the existing Camels. A fossil
Camel is also found in the Pleistocene of Algeria.
Auchenia} — Dentition of adults normally : % \, c y, P f> m %■>
total 32 — one of the lower premolars may, however, be wanting. In
the upper jaw there is a compressed, sharp, pointed laniariform incisor
near the hinder edge of the premaxilla, followed, in the male at least,
by a moderate-sized, pointed, curved true canine in the anterior part
of the maxilla. The isolated canine-like premolar which follows in
the Camels is not present. The teeth of the molar series, which are
in contact with each other, consist of two very small premolars (the
first almost rudimentary) and three broad molars, constructed gener-
ally like those of Camelus. In the lower jaw the three incisors are
long, spatulate, and procumbent ; the outer ones being the smallest.
Next to these is a curved, suberect canine, followed after an interval
by an isolated, minute, and often deciduous simple conical premolar ;
then a contiguous series of one premolar and three molars, which
differ from those of existing species of Camelus in having a small
accessory column at the anterior outer edge. The skull generally
resembles that of Camelus, the relatively larger brain-cavity and
1 Illiger, Prodromus Syst. Marnm. p. 103 (1811).
CAMELID.K
:oo
orbits and less developed cranial ridges being due to its smaller
size. The nasal bones are shorter and broader, and are joined
by the premaxillae. Vertebra: C 7, 1) 12, L 7, S 4, C 15-20.
Ears rather long and pointed. No dorsal hum}). Feet narrow,
the tees being nunc separated than in the camels, each hav-
ing a distinct plantar pad. Tail short. Hairy covering long and
woolly. Size (in existing forms) smaller, and general form lighter
than in the Camels. At present and within historic times the
Fjg. 115. — Llama (Auchenia glama), from an animal living in the Gardens
of the Zoological Society of London.
genus is entirely confined to the western side and southernmost
parts of South America, but fossil remains have been found in
the caves of Brazil, in the pampas of the Argentine republic, and
in Central and North America.
The word Llama, sometimes spelt Lama, is the name by which
the Peruvians designated one of a small group of closely allied
animals, which, before the Spanish conquest of America, were the
only domesticated hoofed mammals of the country, being kept, not
only for their value as beasts of burden, but also for their flesh,
hides, and wool, — in fact, supplying in the domestic economy of
the people the place of the horse, the ox, the goat, and the sheep
of the Old World. The word is now sometimes restricted to one
3oo
L'XGULATA
particular species or variety of the group, and sometimes used in a
generic sense to cover the whole. Although they were often com-
pared by early writers to sheep, and spoken of as such, their affinity
to the camel was very soon perceived, and they were included in
the genus Camelus in the Systema Nature? of Linnaeus. They were,
however, separated by Cuvier in 1800 under the name of Lama,
changed by Illiger in 1811 to Auchenia (in allusion to the great
length of neck, avxrjv), a term afterwards adopted by Cuvier, and
almost universally accepted by systematic zoologists, although there
has been of late a disposition to revive the earlier name.
In essential structural characters, as well as in general appear-
ance and habits, all the animals of this genus very closely resemble
each other, so that the question as to whether they should be
considered as belonging to one, two, or more species has been one
which has led to a large amount of controversy among naturalists.
The question has been much complicated by the circumstances of
the great majority of individuals which have come under observa-
tion being either in a completely or partially domesticated state,
and descended from ancestors which from time immemorial have
been in like condition, one which always tends to produce a certain
amount of variation from the original type. It has, however, lost
much of its importance since the doctrine of the distinct origin of
species has been generally abandoned.
The four forms commonly distinguished by the inhabitants of
South America are recog-
naturalists
nised by some
as distinct species, and have
had specific designations
attached to them, though
usually with expressions of
doubt, and with great diffi-
culties in defining their dis-
tinctive characteristics.
These are (1) the Llama,
Auchenia glama (Linn.), or
Lama peruana (Tiedemann) ;
(2) the Alpaca, A. pacos
Linn.) ; (3) the Guanaco or
Huanaco, A. hmnaous (Mo-
lina) ; and (4) the Vicugna,
A. vicugna (Molina), or A.
vicunna, (Cuv.) The first
and second are only known in the domestic state, and are variable
in size and colour, being often white, black, or piebald. The third
and fourth are wild, and of a nearly uniform light-brown colour,
passing into white below. They certainly differ from each other,
Fin. 116, — Head of Vicugna, from an animal living
in the Gardens of the Zoological Society of London.
CAME LI IKE
301
Fig. 117. — Head of Guanaco, from an animal living
in the Gardens of the Zoological Society of London.
the Vicugna being smaller, more slender in its proportions, and
having a shorter head (Fig. 116) than the Guanaco (Fig. 117).
It may therefore, according
to the usual view of species,
l>e considered distinct. It
lives in herds on the bleak
and elevated parts of the
mountain range bordering
the region of perpetual
snow, amidst rocks and
precipices, occurring in
various suitable localities
throughout Peru, in the
southern part of Ecuador,
and as far south as the
middle of Bolivia. Its
manners very much re-
semble those of the Chamois
of the European Alps; and
it is as vigilant, wild, and
timid. The -wool is ex-
tremely delicate and soft, and highly valued for the purposes of
weaving, hut the quantity which each animal produces is not great.
The Guanaco has an extensive geographical range, from the
highlands of the Andean region of Ecuador and Peru to the open
plains of Patagonia, and even the wooded islands of Tierra del
Fuego. It constitutes the principal food of the Patagonian Indians,
and its skin is invaluable to them, as furnishing the material out
of which their long robes are constructed. It is about the size of
a European Red Deer, and is an elegant animal, being possessed
of a long, slender, gracefully curved neck and fine legs. Dr.
Cunningham, 1 speaking from observation on wild animals, says : —
"It is not easy to describe its general appearance, which combines
some of the characters of a camel, a deer, and a goat. The body,
deep at the breast but very small at the loins, is covered with long,
soft, very fine hair, which on the upper parts is of a kind of fawn-
colour, and beneath varies from a very pale yellow to the most
beautiful snow-white. The head is provided with large ears, in
general carried well back, and is covered with short grayish hair,
which is darkest on the forehead. Occasionally the face is nearly
black. As a rule it lives in flocks of from half a dozen to several
hundreds, but solitary individuals are now and then to be met with.
They are very difficult to approach sufficiently near to admit of an
easy shot, as they are extremely wary, but, on being disturbed,
canter off at a pace which soon puts a safe distance between them
1 Natural History of the Strait "/Magellan, 1871.
302 UNGULATA
and the sportsman, even though he should be mounted. Despite
their timidity, however, they are possessed of great curiosity, and
will sometimes advance within a comparatively short distance of an
unknown object, at which they will gaze fixedly till they take
alarm, when they effect a speedy retreat. Their cry is very peculiar,
being something between the belling of a deer and the neigh of a
horse. It would be difficult to overestimate their numbers upon
the Patagonian plains ; for in whatever direction we walked we
always came upon numbers of portions of their skeletons and
detached bones."
Darwin, who has given an interesting account of the habits of
the Guanaco in his Naturalist's Voyage, says that they readily take
to the water, and were seen several times at Port Valdes swimming
from island to island.
The Llama is only known as a domestic animal, and is chiefly
met with in the southern part of Peru. Burmeister, a very com-
petent writer on the subject, says that he is perfectly satisfied that
it is the descendant of the wild Guanaco, an opinion opposed to
that of Tschudi. It generally attains a larger size than the
Guanaco, and is usually white or spotted with brown or black,
and sometimes altogether black. The earliest and often -quoted
account of this animal by Agustin de Zarate, treasurer-general of
Peru in 1544, will bear repeating as an excellent summary of the
general character and uses to which it was put by the Peruvians at
the time of the Spanish conquest. He speaks of the Llama as a
sheep, observing, however, that it is camel-like in shape though
destitute of a hump : —
" In places where there is no snow the natives want water, and
to supply this they fill the skins of sheep with water and make
other living sheep carry them ; for, it must be remarked, these
sheep of Peru are large enough to serve as beasts of burden. They
can carry about one hundred pounds or more, and the Spaniards
used to ride them, and they would go four or five leagues a day.
"When they are weary they lie down upon the ground ; and as there
are no means of making them get up, either by beating or assisting
them, the load must of necessity be taken off. When there is a
man on one of them, if the beast is tired and urged to go on, he
turns his head round and discharges his saliva, which has an un-
pleasant odour, into the rider's face. These animals are of great
use and profit to their masters, for their wool is very good and fine,
particularly that of the species called Pacas, which have very long-
fleeces ; and the expense of their food is trifling, as a handful of
maize suffices them, and they can go four or five days without
water. Their flesh is as good as that of the fat sheep of Castile.
There are now public shambles for the sale of their flesh in all parts
of Peru, which was not the case when the Spaniards came first ; for
CAM ELI D. K 303
when one Indian had killed a sheep his neighbours came and took
whal they wanted, and then another Indian killed a sheep in his
turn."
The disagreeable habit here noticed of spitting in the face of
persons whose presence is obnoxious is common to .all the group, as
may be daily witnessed in specimens in confinement in the
menageries^of Europe. One of the principal labours to which the
Llamas were subjected at the time of the Spanish conquest was
that of bringing down ore from the mines in the mountains.
Gregory de Bolivar estimated that in his day as many as three
hundred thousand were employed in the transport of the produce
of the mines of Potosi alone ; but since the introduction of horses,
mules, and donkeys the importance of the Llama as a beast of
burden has greatly diminished.
The Alpaca, though believed by many naturalists to be a variety
of the Vicugna, is more probably, like the Llama, derived from the
Guanaco, having the naked callosities on the hind limbs, and the
relatively large skull of the latter. It is usually found in a
domesticated or semi-domesticated state, being kept in large flocks
which graze on the level heights of the Andes of southern Peru
and northern Bolivia at an elevation of from 14,000 to 16,000 feet
above the sea-level, throughout the year. It is smaller than the
Llama, and, unlike that animal, is not used as a beast of burden,
but is valued only for its wool, of which the Indian blankets and
ponchas are made. Its colour is usually dark brown or black.
Mention has already been made of the occurrence of fossil
Llamas in America, but some diversity of view obtains as to the
generic position of some of these forms, owing to variations in their
dental formula. Remains apparently referable to the existing
species occur in the cavern-deposits of Brazil. In the Pleistocene
of Mexico we meet with A. (Pahmchenia) magna, which attained
the size of a Camel, and had always two, and occasionally three,
lower premolars ; while in one South American Pleistocene species,
which has been generically separated as Hemiauchenia, there were
invariably three premolars in each jaw. In A. (Holomeniscus)
liestcrna, from the Pleistocene of North America, which was equal
in size to A. magna, the premolars were reduced to one in each
jaw ; and the same condition obtains in A. (Eschatius) mtakericma,
Avhere, however, the upper one is of simpler structure.
Extinct Gameloids. — Until within the last few years the existence
of two genera having so very much in common as the Camels and
the Llamas, and yet so completely isolated geographically, had not
received any satisfactory explanation ; for the old idea that they in
some way " represented " each other in the two hemispheres of the
world was a mere fancy without philosophical basis. The dis-
coveries made mostly within the past twenty years of a vast and
3 o4 UNGULATA
previously unsuspected extinct fauna in the American continent of
the Tertiary period, as interpreted by Leidy, Cope, Marsh, and
others, has thrown a flood of light upon the early history of this
family, and upon its relations to other mammals.
There have been found in these regions many Camel -like
animals exhibiting different generic modifications ; and, what is
more interesting, a gradual series of changes, coinciding with the
antiquity of the deposits in which they are found, have been traced
from the thoroughly differentiated species of the modern epoch
down through the Pliocene to the early Miocene beds, where, their
characters having become by degrees more generalised, they have
lost all that specially distinguishes them as Camelidce, and are
merged into forms common to the ancestral type of all the other
sections of the Artiodactyles. Hitherto none of these annectant
forms have been found in any of the fossiliferous strata of the Old
World ; and it may therefore be fairly surmised (according to
the evidence at present before us) that America was the original
home of the Tylopoda, and that the true Camels have passed over into
the Old World, probably by way of the north of Asia, where we
have every reason to believe there was formerly a free communica-
tion between the continents, and then, gradually driven southward,
perhaps by changes of climate, having become isolated, have under-
gone some further special modifications ; while those members of
the family that remained in their original birthplace have become,
through causes not clearly understood, restricted solely to the
southern or most distant part of the continent. The occurrence
in the dentition of the fossil Siwalik Camels of a feature now
found only in Auchenia is especially interesting from this point
of view.
Briefly referring to some of these fossil types, Ave may note
that Pliauchenia, of the Loup Fork beds (Lower Pliocene) of
the United States, has three lower premolars, while in Procamelus
there were four of these teeth. In Protolabis of the Miocene
we have a more generalised form, in which the dental formula
is i f , c \, p f, m % ; and from this type a transition may be
traced to Poebrothcrvnn, which, while having the same dental
formula, was no larger than a Fox, and had the third and fourth
metacarpals separate, with rudiments of the fourth and fifth. The
earliest undoubted representative of the group is Leptotragulus, of
the Uinta Eocene, which appears to have been closely allied to
Po'ebrotheriim. It is, however, probable that the first lower pre-
molar was wanting ; while the other premolars of the mandible
were much shorter antero-posteriorly than in the last-named genus.
The manus, moreover, appears to have been less reduced, the second
metacarpal retaining its connection with the magnum. It is
suggested that Leptotragulus may have been derived from the
TRAGULW.K 3°5
Bunodonl genus Homacodon of the Bridger Eocene, mentioned
among the Ccmothemdce.
Tragulina.
Family Tragulid.e.
Xo teeth in premaxillse. Upper canines well developed, especi-
ally in the males; narrow and pointed. Lower canines incisiform.
Xo caniniform premolars in either jaw, all the premolars except the
last in the upper jaw being secant. Molariform teeth in a con-
tinuous series, consisting of p %, m %. Odontoid process of axis
vertebra conical. Fibula complete. Four complete toes on each
foot. The middle metapodials generally confluent, the outer ones
(second and fifth) very slender but complete, i.e. extending from
the carpus or tarsus to the digit. Navicular, cuboid, and ectocunei-
form bones of tarsus united. Tympanic bullae of skull filled with
cancellar tissue. Xo frontal appendages. Eliminating, but the
stomach with only three distinct compartments, the maniplies or
third cavity of the stomach of the Pecora being rudimentary.
Placenta diffused.
This section is represented only by the single family Tragulidce,
containing a few animals of small size, commonly known as
Chevrotains, intermediate in their structure between the Deer, the
Camels, and the Pigs. The large size of the canines of the male and
the absence of horns caused them to be associated formerly with
Moschus, one of the Cervidce ; hence they are often spoken of as
>; Pigmy Musk-Deer," although they have no musk-secreting gland,
or, except in the above-named trivial external characters, no special
affinities with the true Musk-Deer. There has scarcely been a more
troublesome and obdurate error in zoology than in this association
of animals so really distinct. It has been troublesome, not only in
preventing a just conception of the relations of existing Artiodac-
tyles, but also in causing great confusion and hindrance in palceonto-
logical researches among allied forms ; and most obdurate, inasmuch
as all that has been recently done in advancing our knowledge of
both groups has not succeeded in eradicating it, not only from
nearly every one of our zoological text-books, whether British or
Continental, but even from works of the highest scientific pre-
tensions.
The family is now generally divided into two genera.
Traguhis, 1 containing the smallest of the existing Ungulates,
animals having more of the general aspects and habits of some
Kodents, as the Agoutis, than of the rest of their own order. The
best -known species are T. javanicus, T. najm, T. stanleyanus, and
1 Pallas, Spicikgia Zoologica, vol. xiii. p. l'7 (1779).
20
3°6
UNGULATA
T. memmina. The first three are from the Malay Peninsula, or the
islands of the Indo-Malayan Archipelago, the last from Ceylon and
India. A fossil species occurs in the Pliocene of the latter country.
Dorcatheriwm 1 is distinguished chiefly by the feet being stouter
and shorter, the outer toes better developed, and the two middle
metacarpals not ankylosed together. Its dental formula (as that
of Trogulus) is usually i ■§-, c \, p %, ro| =34. Vertebrae: C 7,
D 13, L6, S 5, C 12-13. The only existing species, I), aquaiicum
(Fig. 118), from the west coast of Africa, is rather larger than any
y
Fig. IIS. — The African Water-Chevrotain {Dorcafherium aguaticum).
of the Asiatic Chevrotains, which it otherwise much resembles, but
it is said to frequent the banks of streams, and have much the
habits of Pigs. It is of a rich brown colour, with back and sides
spotted and striped with white. It is evidently the survivor of a
very ancient form, as remains of the type species (D. naui), only
differing in size, occur in the lower Pliocene and Miocene of
Europe ; fossil species are also found in the Indian Pliocene.
In D. naui there are, at least frequently, four lower premolars,
while the existing species has but three of these teeth.
Extinct Traguloids. — A number of small selenodont Artiodactyles
1 Kaup, Ossemcns Fossiles cle Darmstadt, pt. 5, p. 92 (1836). This name,
which was proposed for a fossil species, antedates Ryomoschus, Gray, applied to
the living form.
PECORA 307
from various Miocene and Pliocene deposits appear to connect the
modern Tragulina so closely with Greloms (p. 294), and thus with
the ancestral Cervi<f" , that their classification is almost an impossi
bility. Thus Leptomeryx, from the Miocene of the United States,
is regarded as a Traguloid, having four premolars in each jaw
and with the metatarsals fused into a cannon-bone. Prodremoth Hum,
of the Upper Eocene Phosphorites of France, diners in that the
metacarpals also form a cannon-bone ; while in the American
Hyperiragulus, both metacarpals and metatarsals remain separate.
Bachitherium, of the French Phosphorites, apparently presents
affinity with Grdocus, Prodremotherium, and Dorcatherium. In this
genus the first of the four lower premolars assumes the character
and function of a canine, the true canine being incisor-like, and
there are traces of minute upper incisors.
Pecora, or Cotylophora.
No premaxillary teeth or caniniform premolars. Upper canines
generally absent, though sometimes largely developed. Inferior
incisors, three on each side Avith an incisiform canine in contact
with them. Molariform teeth consisting of p -§, m f, in con-
tinuous series. Auditory bullae simple and hollow within. Odon-
toid process in the form of a crescent, hollow above. Distal
extremity of the fibula represented by a distinct malleolar bone of
peculiar shape, articulating with the outer surface of the lower end
of the tibia. Third and fourth metacarpals and metatarsals con-
fluent. Outer or lateral toes small and rudimentary, or in some
cases entirely suppressed ; their metapodial bones never complete
in existing forms. Navicular and cuboid bones of tarsus united.
Horns or antlers usually present, at least in the male sex. Left
brachial artery arising from a common innominate trunk, instead
of coming off separately from the aortic arch as in the preced-
ing sections. Stomach with four complete cavities. Placenta
cotyledonous. 1
The Pecora or true Ruminants form at the present time an
extremely homogeneous group, one of the best-defined and most
closely united of any of the Mammalia. But, though the original
or common type has never been departed from in essentials, varia-
tion has been very active among them within certain limits ; and
the great difficulty which all zoologists have felt in subdivid-
ing them into natural minor groups arises from the fact that
the changes in different organs (feet, skull, frontal appendages,
teeth, cutaneous glands, etc.) have proceeded with such apparent
irregularity and absence of correlation that the different modifica-
1 For the anatomy of this group see A. H. Garrod, Proc. Zool. Soe. 1 Q 77, p. 2.
3o8
UNGULATA
tions of these parts are most variously combined in different
members of the group. It appears, however, extremely probable
that they soon branched into two main types, represented in the
present day by the Cervicke and the Bovkke, — otherwise the
antlered and horned Ruminants. Intermediate smaller branches
produced the existing Musk-Deer and Giraffe, as well as the extinct
Helladotherium inclining to the first-named group, and the extinct
Sivatherium, Brahmatherium, Hydaspitherium, and others more allied
to the latter, although upon the true relationship of these forms
there is a difference of opinion.
The earliest forms of true Pecora, as Palceomeryx, generally had
no frontal appendages, and some few forms continue to the present
day in a similar case. In the very large majority, however, either
in both sexes or in the male
only, a pair or occasionally two
pairs (Tetraceros and the extinct
Sivatherium) of processes are de-
veloped from the frontal bones
as weapons of offence and de-
fence, these being almost always
formed on one or other of two
types.
1.
of true bone, covered during
their growth with vascular,
sensitive integument coated with
short hair. When the growth
of the antler is complete, the
supply of blood to it ceases, the
skin dies and peels off, leaving
the bone bare and insensible,
and after a time, by a process
of absorption near the base, it
becomes detached from the skull
and is "shed" (Fig. 119). A
more or less elongated portion
6 beztine; c tres tine; d, crown or royal Qr " pedicle " always remains Oil
(After Owen.) i i -n <• i e
the skull, from the summit of
which a new antler is developed. In the greater number of exist-
ing species of Deer this process is repeated with great regularity at
the same period of each year. The antler may be simple, straight,
subcylindrical, tapering and pointed, but more often it sends off
one or more branches called "tines" or "snags" (Fig. 119). In
this case the main stem is termed the " beam." Commonly all the
branches of the antler are cylindrical and gradually tapering.
Sometimes they are more or less expanded and flattened, the
1 Antlers " are outgrowths
Fig. 119. — A shed right antler of the Red Beer
{Cervus elaphus), found in an Irish lake, a, Brow
tine
tine
PECORA
309
antler being then said to be "palmated." In young animals the
antlers are always small and simple, and in those species in which
the}- are variously branched or palmated, this condition is only
gradually ac-
quired in several
successive annual
growths. An
interesting paral-
lel has been ob-
served here, as
in so many other
cases, between
the development
of the race and
that of the in-
dividual. Thus
the earliest
known forms of
Deer, those of
the Lower Mio-
cene, generally
have no antlers,
as in the young
of the existing;
species. The
Deer of the
Middle Miocene
have simple ant-
lers, with not
more than two
branches, as in
. . -~ ( Fig. 120. — Head of Deer (Cervus scnomburgki), showing antlers.
existing Deer 01 FlY)I11 s c i ate r ( mc. zooi. Soc. 1S77, p. 6S2.
the second year ;
but it is not until the Pliocene and Pleistocene times that Deer
occur with antlers developed with that luxuriance of growth and
beauty of form characteristic of some of the existing species in a
perfectly adult state. Among recent Cervidce, antlers are wanting
in the genera Moschus and Hydropotes ; they are present in both sexes
in Tarandus (the Reindeer), and in the male sex only in all others.
In those forms with the most complex antlers (Figs. 119, 120)
the tine immediately over the forehead is termed the brow tine, the
next one the bez tine, and the third one the tres tine ; the mass of
points at the summit of the antler being termed either the royal
and surroyal tines, or collectively the crown. The nodulated bony
ring at the base of the antler, just above the point at which it
separates from the pedicle when it is shed, is termed the burr.
IP
ft: 11
'Mm
3io
UXGULATA
2. The horns of the Bovidce consist of permanent, conical,
usually curved bony processes, into which air-cells continued from
the frontal sinuses
often extend,
called "horn-
cores," ensheathed
in a case of true
horn, an epider-
mic development
of fibrous struc-
ture, which grows
conti nuously,
though slowly,
from the base, and
wears away at the
apex, but is very
rarely shed entire.
The only existing
species in which
the latter process
occurs regularly
and periodically
is the American
Prong-Buck
(Aiifiloaqrra), in
which the horns
also differ from
those of all others
in being bifurc-
ated. Horns are
not present at
birth, but begin
to grow very soon
afterwards. The
From males of all exist-
ing Bovidce possess
them, and they are also present (though usually not so fully
developed) in the females of all except the genera BoselapJms,
Sfrrpsiceros, Tragehphus, Antilope, JEpyceros, Saiga, Cobus, Cervkajpra,
Pelea, Nanotragus, Neotragus, Cephcdophus, and Tetraeeros; as well as
in some species of Gazella, such as 67. picticaudata and 67. walleri.
Another character by which different members of the Pecora can be
distinguished among themselves is derived from the nature of the molar
teeth. Although there is nothing in the general mode and arrange-
ment of the enamel -folds, or in the accessory columns, absolutely
distinctive between the two principal families, existing species may
Fig. 121.— Head of Antelope (Gazella granti), showing horns.
Sir V. Brooke, Proc. Zool. Soc. 187S, p. 724.
PECO R A
3"
generally be distinguished, inasmuch as t be true molars of the ( '< rvidce
are more or less brachydont, and those of the Bovidce generally
hypsodont, i.e. the teeth of the former have
comparatively short crowns (Fig. 122), which,
as in most mammals, take their place at once
with the neck (or point where the crown and
root join) on a level with or a little ahove the
alveolar border, ami remain in this position
throughout the animal's life; whereas in the
other forms (Fig. 123), the crown heing lengthened
and the root small, the neck does not come up
to the alveolar level until a considerable part ^JZ^SZ
of the surface has worn away, and the crown of unsis, to show brachydont
the tooth thus appears for the greater part of type. (From the Patacmfo-
the animal's life partially buried in the socket. 0CJia
In this form of tooth (which is almost always most developed
in the posterior molars of the permanent series) the constituent
columns of the crown are necessarily nearly parallel, whereas
Fio. 122. — Crown sur-
]•,,.. 123.— Inner and outer aspects of an almost unworn left upper molar of the Nilghai
(Boa ' "(locamelus), to show hypsodont type. (From the Pukeontologia Indica.)
in the first-described they diverge from the neck towards the free
or grinding surface of the tooth. In the completely hypsodont
form the interstices of the lengthened columnar folds of enamel
and dentine are filled up with cement, which gives stability to
the whole organ, and is entirely or nearly wanting in the short-
crowned teeth. The same modification from low to high crowns
without essential alteration of pattern is seen in an even still
more marked manner in some of the Perissodactyle Ungulates,
the tooth of the Horse bearing to that of Anchitherium the same
relation as that of an Ox does to the early selenodont Artiodactyles.
312
UNGULATA
A parallel modification has also taken place in the molar teeth of
the Proboscidea.
As the hypsodont tooth is essentially a modification of, and, as
it were, an improvement upon, the brachydont, it is but natural to
expect that all intermediate forms may be met with. Even among
the Deer themselves, as pointed out by Lartet, the most ancient
have very short molars, and the depressions on the grinding surface
are so shallow that the bottom is always visible ; while in the Cervidce
of the more recent Tertiary periods, and especially the Pleistocene
and living species, these same cavities are so deep that whatever be
the state of the dentition the bottom cannot be seen. Some
existing Deer, as the Axis, are far more hypsodont than the majority
of the family ; and, on the other hand, many of the Antelopes (as
Tragelaplms) retain much of the brachydont character, which is,
however, completely lost in the more modern and highly specialised
Sheep and Oxen.
Fig. 124.— Stomach of Ruminant opened to show internal structure, a, Oesophagus ; b,
rumen or paunch ; c, reticulum or honey-comb bag ; d, psalterium or manyplies ; e, abomasum
or reed ; /, duodenum.
The complicated stomach of the Pecora (Fig. 124), which is
necessary for the performance of the peculiar function known as
"chewing the cud" — a function common also to the Tragulina
and Tylopoda — is divided into four well-defined compartments,
known as (1) the Rumen or Paunch, (2) the Reticulum or Honey-
comb Bag, (3) the Psalterium or Manyplies, (4) the Abomasum
or Reed. The paunch is a very capacious receptacle, shaped like a
blunted cone bent partly upon itself. Into its broader base opens
the oesophagus or gullet at a spot not far removed from its Avide
orifice of communication with the second stomach or honey-
comb bag. Its inner walls are nearly uniformly covered with a
pale mucous membrane, which is beset with innumerable close-set,
short, and slender villi, resembling very much the "pile" on
velvet The honey-comb bag is very much smaller than the paunch.
CERVID& 313
It is nearly globose in shape, and receives its name on account of
the peculiar arrangement of its mucous membrane which forms
shallow hexagonal cells all over its inner surface. Running along
its upper wall there is a deep groove, coursing from the first to the
third stomach. This groove plays an important part in the act of
rumination. Its walls are muscular, like those of the viscus with
which it is associated, which allows its calibre to be altered. .Some-
times it completely closes round so as to become converted into a
tube by the opposition of its edges. At others it forms an open
canal. The manvplies is globular in form, and its lining membrane
is raised into longitudinal folds or lamina? arranged very much like
the leaves of a book, and very close together. Their surfaces
are roughened by the presence of small projections or papillae.
The reed is the proper digestive stomach, corresponding with the
same organ in man. Its shape is somewhat pyriform, and its
walls are formed of a smooth mucous membrane, which secretes the
gastric juice.
When the food is first swallowed it is conveyed into the paunch,
and after undergoing a softening process there it is regurgitated
into the mouth, and undergoes a further trituration by the molar
teeth and mixture with the secretion of the salivary and buccal
glands. It is then swallowed again, but now passes directly through
the lief ore-mentioned groove into the manyplies, and, after filtering
through the numerous folds of the lining membrane of this cavity,
finally reaches the fourth or digestive stomach.
The placenta of the Pecora is characterised by the foetal villi
being collected into groups or cotyledons, which may present either
a convex or a concave surface to the uterus. These cotyledons are
received into permanent elevations in the mucous membrane of the
uterus, the surfaces of which present a curvature which is the
reverse of the cotyledons.
Family Cervid.E.
Frontal appendages, when present, in the form of antlers. First
molar, at least, in both jaws brachydont. Two orifices to the lachrymal
duct, situated on or inside the rim of the orbit. An antorbital or
lachrymal vacuity of such dimensions as to exclude the lachrymal bone
from articulation with the nasal. Upper canines usually present in
both sexes, and sometimes attaining a very great size in the male
(see Fig. 134). Lateral digits of both fore and hind feet almost
always present, and frequently the distal ends of the metapodials.
Placenta with few cotyledons. Gall-bladder absent (except in
Moschiis). This family contains numerous species, having a wide
geographical distribution, ranging in the New World from the Arctic
3H
UNGULATA
Circle as far south as Chili, and in the Old World throughout the
whole of Europe and Asia, though absent in the Ethiopian and
Australian regions.
It may be divided into two subfamilies.
Subfamily Mosehinse. — This subfamily is represented solely by
the Musk-Deer, which differs so remarkably from the true Deer that
it is considered by several writers as the representative of a separate
family. The late Professor Garrod even suggested that it should
be regarded as an extremely aberrant member of the Bovidce.
Moschus. 1 — The Musk-Deer (Fig. 125) in many respects stands by
Fig. 125. — The Musk-Deer (Moschus mosvliiferus).
itself as an isolated zoological form, retaining characters belonging to
the older and more generalised types of ruminants before they were
distinctly separated into the horned and the antlered sections now
dominant upon the earth. One of these characters is that both
sexes are entirely devoid of any sort of frontal appendage. In this,
however, it agrees with one existing genus of true Deer (Hydropotes) ;
and, as in that animal, the upper canine teeth of the males are
remarkably developed, long, slender, sharp pointed, and gently
curved, projecting downwards out of the mouth with the ends
turned somewhat backwards. Vertebra? : C 7, D 1 4, L 5, S 5, C 6.
Among the anatomical peculiarities in which it differs from all
true Deer and agrees with the Bovidce is the presence of a gall-
1 Linn. Syst. Nat. 12th ed. vol. i. p. 91 (1766).
CERl'WJ-: 315
bladder. The hemispheres of the brain are but slightly convoluted,
and the cotyledons of the placenta are arranged in a peculiar linear
manner. 1
Although, owing to variations of colour presented by different
individuals in different localities and seasons, several nominal species
have been described, zoologists are now generally agreed that there
is but one, the Mosckus moschiferus of Linnaeus. In size it is rather
less than the European lioe Deer, being about 20 inches high at the
shoulder. Its limbs, especially the hinder ones, are long. The feet
are remarkable for the great development of the lateral pair of hoofs,
and for the freedom of motion they all present, so that they appear
to have the power of grasping projecting rocky points, — a power
which must be of great assistance to the animal in steadying it in
its agile bounds among the crags of its native haunts. The ears are
large, and the tail quite rudimentary. The hair covering the body
is long, coarse, and of a peculiarly brittle and pith-like character,
breaking with the application of an extremely slight force ; it is
generally of a grayish-brown colour, sometimes inclined to yellowish-
red, and often variegated with lighter patches. The Musk-Deer has
a wide distribution over the highlands of central and eastern Asia,
including the greater part of southern Siberia, and extends to
Kashmir on the south-west and Cochin-China on the south-east,
always, however, at considerable elevations, — being rarely found in
summer below r 7000 feet above the sea-level, and ranging as high as
the limits of the thickets of birch or pines, among which it mostly
conceals itself in the day-time. It is a hardy, solitary, and retiring
animal, chiefly nocturnal in its habits, and almost always found
alone, rarely in pairs, and never in herds. It is exceedingly active and
sure-footed, having few equals in traversing rocky and precipitous
ground ; and it feeds on moss, grass, and leaves of the plants
which grow on the mountains among which it makes its home.
Most of the animals of the group to Avhich the Musk-Deer
belongs, in fact the large majority of mammals, have some portion
of the cutaneous surface peculiarly modified and provided with
glands secreting some odorous and oleaginous substance specially
characteristic of the species. This, correlated with the extraordin-
ary development of the olfactory organs, appears to offer the princi-
pal means by which animals in a state of nature become aware of
the presence of other individuals of their own species, or of those
inimical to them, even at very great distances, and hence it is of
extreme importance both to the well-being of the individual and to
the continuance of the race. The situation of this specially modified
portion of skin is extremely various, sometimes between the toes,
as in Sheep, sometimes on the face in front of the eyes, as in many
1 For the anatomy of Moschus see Flower, Proc. Zool. Soc. 1875, p. 159 ;
and Garrod, ibid. 1877, p. 287.
316 UNGULATA
Deer and Antelopes. Sometimes it is in the form of a simple depres-
sion or shallow recess, often very deeply involuted, and in its fullest
state of development it forms a distinct pouch or sac with a narrow
tubular orifice. In this sac a considerable quantity of the secretion
can accumulate until discharged by the action of a compressor
muscle which surrounds it. This is the form taken by the special
gland of the Musk-Deer, which has made the animal so well known,
and has proved the cause of an unremitting persecution to its
possessor. It is found in the male only, and is a sac about the size
of a very small orange, situated beneath the skin of the abdomen,
the orifice being immediately in front of the preputial aperture.
The secretion with which the sac is filled is of dark-brown or
chocolate colour, and when fresh described as being of the consist-
ence of " moist gingerbread," but becoming dry and granular after
keeping. It has a peculiar and very powerful scent, which when
properly diluted and treated forms the basis of many of our most
admired perfumes. When the animal is killed the whole gland or
" pod " is cut out and dried, and in this form reaches the market of
the Western World, chiefly through China.
Subfamily Cervinse. — This subfamily includes all the true Deer.
According to the arrangement proposed by Sir V. Brooke l the
existing Cervince may be divided into the sections Plesiometacarpalia
and Telemetacarpalia.
Plesiometacarpalia. — In this section, which is mainly character-
istic of the Old World, the proximal portions of the lateral (second
and fifth) metacarpals persist, and the vomer is never so ossified
as to divide the posterior osseous nares into two distinct passages.
The premaxillae nearly always articulate with the nasals.
Cervulus. 2 — Antlers half the length of the head, placed on
pedicles nearly equal to them in length. Brow tine short,
inclined inwards and upwards ; terminal extremity of beam
unbranched, and curved downwards and inwards. Lachrymal fossa
of skull very large, and extending into facial part of jugal ; lach-
rymal (antorbital) vacuity moderate. Ascending portion of pre-
maxillae at least as long as nasals. A permanent ridge extending
from each pedicle over the orbit, lachrymal fossa and vacuity.
Auditory bulla much inflated. Upper canines of males very large.
Ectocuneiform united with naviculo-cuboid of tarsus. No traces of
the phalanges of the lateral digits.
The native name Muntjac has been generally adopted in
European languages for a small group of Deer indigenous to the
southern and eastern parts of Asia and the adjacent islands, which
are separated by very marked characters from all their allies. They
are also called "Kijang" or " Kidjang," and constitute the genus
1 Proc. Zooh Soe. 1S78, p. 889.
- Dc Blainville, Bull. Soc. Philom. 1816, p. 74.
CERVID.E 317
( '< rvulus of Blainville and most zoologists ; — St//l<>ccri>s of Hamilton-
Smith, and Prox of Ogilby. They are all of small size compared
with the majority of Dorr, and have long bodies and rather short
limbs and neck. The antlers, which as in most Deer are present in
the male only, are small and simple, and the main stem or beam,
after giving off a very short brow tine, inclines backwards and up-
wards, is unbranched and pointed, and when fully developed curves
inwards and somewhat downwards at the tip. These small antlers
are supported upon pedicles or permanent processes of the frontal
bones, longer than in any other Deer, and the front edges of which
are continued downwards as strong ridges passing along the sides of
the face above the orbits, and serving to protect the large supra-
orbital glands lying on their inner sides. The lachrymal fossa of
the skull, in which is lodged the large suborbital gland or crumen,
is of great depth and extent. The upper canine teeth of the males
are strongly developed and sharp, curving downwards, backwards,
and outwards, projecting visibly outside the mouth as tusks, and
loosely implanted in their sockets. In the females they are very
much smaller. The limbs exhibit several structural peculiarities not
found in other Deer. The lateral digits of both fore and hind feet are
very little developed, the hoofs alone being present and their bony
supports (found in all other Deer) wanting. There is a tufted gland
on the outer side of the metatarsus.
The Muntjacs are solitary animals, very rarely even two being
seen together. They are fond of hilly ground covered with forests,
in the dense thickets of which they pass most of their time, only
coming to the skirts of the woods at morning and evening to
graze. They carry the head and neck Ioav and the hind-quarters
high, their action in running being peculiar and not very elegant,
somewhat resembling the pace of a sheep. Though with no
power of sustained speed or extensive leap, they are remarkable
for flexibility of body and facility of creeping through tangled
underwood. They are often called by Indian sportsmen " Barking
Deer," a name given on account of their alarm cry, a kind of
short shrill bark, like that of a fox but louder, which may often
be heard in the jungles they frequent both by day and by night.
When attacked by dogs the males use their sharp canine teeth
with great vigour, inflicting upon their opponents deep and even
dangerous wounds.
There is some difference of opinion among zoologists as to the
number of species of the genus Cervuhis. Sir Victor Brooke, who
investigated this question in 1878 (see Proceedings of the Zoological
Society iff London for that year, p. 898), came to the conclusion that
there are certainly three which are quite well marked, viz. —
C. muntjac (Fig. 126), found in British India, Burma, the Malay
Peninsula, Sumatra, Java, Hainan, Banca, and Borneo. The general
3i8
UNGULATA
colour is a bright yellowish-red, darker in the upper parts of the
back ; the fore legs from the shoulder downwards and the lower part
of the hind legs, dark bluish-brown ; anterior parts of the face from
the muzzle to between the eyes, brown — a blackish line running up
the inside of each frontal ridge ; chin, throat, inside of hind legs,
and under surface of tail white. The female has a black bristly
tuft of hair on the spot from which the pedicles of the antlers of the
male grow. The average length of the male, according to Jerdon,
is 3 1 feet, tail 7 inches, height 26 to 28 inches. The female is a
little smaller. The specimens from Java, Sumatra, and Borneo are
Fig. 126. — The Muntjac (Ccrvulus muntjac).
of larger size than those from the mainland, and may possibly be of
distinct species or race.
C. lacrymans of Milne-Edwards, or Sclater's Muntjac of Swin-
hoe, from Moupin, and near Hangchow, China.
G. reevesi, a very small species from southern China.
Subsequently the name C. crinifrons has been applied to a Munt-
jac from Ningpo, China, readily distinguished from all other species
by its bushy forehead and long tail. Another species from Tenas-
serim has been described as C. fcce.
Small Deer from the European Pliocene have been provisionally
referred to Cervulus, but the so-called Prox furcatus, of the Miocene,
is now included in Palccomerijx.
Elaphodus. 1 — Antlers very small, unbranched, supported on long,
1 Milne-Edwards, Nbuv. Arch, du Museum, vol. vii. Dull. p. 93 (1872).
CERVin.K
319
slender, converging pedicles. Ascending rami of premaxillse shorter
than nasals. No supraorbital ridges or frontal glands. Upper
canines of male long, but not everted. A distinct frontal tuft
of hair. Other characters as in Cermdus.
This genus (which has also received the name of Lophotragus) is
represented by a small Deer (Fig. 127) from China of about the
same size as the Indian Muntjac. The male has minute simple
antlers and very large canine teeth. There are no supraorbital
Fig. 127.— Male of Elaphodus michianus. From Sclater Proc. Zool. Soc. 1S76, p. 273.
glands, nor is there a tufted gland on the metatarsus. The limbs
have the same peculiarities as in Cervulus, but the mesocuneiform
may also ankylose "with the ectocuneiform, and traces of the meta-
carpals may remain. The hair is coarse and somewhat quill-like.
i \ rms. 1 — The great majority of the Deer of the Old World may
be included in this large genus, which is one not easjr of definition.
The antlers of the male are, however, large, and two or three times
the length of the head, and may be either rounded or palmate ; the
canines are never large ; the ectocuneiform of the tarsus remains
distinct from the naviculo-cuboid ; the lateral digits are represented
by their phalanges ; and the skull does not carry prominent frontal
ridges. Vertebras : C 7, D 13, L 6, S 4, C 11-1 4. The size of the
i Linn. Syst. Kat. 12th ed. vol. i. p. 92 (1766).
UXGULATA
lachrymal fossa and vacuity, and the degree of inflation of the audi-
tory bulla, are subject to variation in the different groups into
which the genus may be divided.
The Busine group is characteristic of the Oriental region, where
it is typically represented by the Sambur (C. aristotelis) of India,
Burma, and China. The antlers are rounded, and often strongly
grooved, without a bez tine, and with the beam simply forked at the
extremity, upright, and but slightly curved ; the angle formed by
the brow tine, which rises close to the burr, being acute. The
molars are markedly hypsodont, with small accessory columns. The
lachrymal fossa is deep and the vacuity large ; the auditory bulla
is slightly inflated and rugose. Tail moderate ; neck maned.
The Sambur, which is abundant in hilly districts, is a fine animal,
standing nearly 5 feet in height, and of massive build ; the general
colour being deep brown. G. equinus, of Borneo, Sumatra, and
Singapore, C. swinhoei, of Formosa, C. philippinus, and C. alfredi of
the Philippines, are closely allied species, of which the two latter
are of smaller dimensions. The Indian Hog Deer (C. porcinus) is a
still smaller form, not larger than the Koe. C. hippelaphus of Java,
C. timoriensis, and C. molucceiisis are distinguished by the posterior
branch of the beam of the antler being considerably larger than the
anterior.
The Rucervine group is another strictly Oriental one, and is
represented by the Swamp Deer (C. duvaucelli) of India, the closely
allied C. schomburgki of Siam, of which the antlers are shown in
Fig. 119 (p. 309), and C. eldi of Burma and Hainan. The beam of
the antler is somewhat flattened, and more curved than in the Rusine
group ; the large brow tine is given off from the beam at an obtuse
angle and curves upwards ; the beam bifurcates into two branches,
which again divide. Skull as in the Rusine group, but relatively
narrower. Tail short ; neck maned.
The Swamp Deer is somewhat smaller than the Sambur, and of
a full yellowish colour. Fossil representatives of this group occur
in the Pliocene of India.
The Elaplmrine group is represented only by the very aberrant
C. davidiamis of Northern China. In size and proportions this
species approximates to the Swamp Deer, but the antlers are peculiar
in rising straight from the brow and then giving off a long and
straight back tine (correlated by Sir V. Brooke with the posterior
branch of the Rusine antler) ; the summit of the beam is forked,
and in old individuals the two tines of the fork may again branch.
Nasals long, and much expanded between the lachrymal vacuities,
of which they form the inner border ; lachrymal fossa large and
deep. Tail long ; neck maned.
The Axine group includes only the well-known Axis of India,
readily distinguished by the white spots Avith which the body is
CERVIDsE
321
marked. Antlers of a Rusine type, the beam being much
curved, and the brow tine usually given off at an acute or
right angle. Molars very hypsodont. The coloration of the
Axis is more brilliant than that of any other member of the
family.
Here may be noticed a group of Deer mainly characteristic of
the eastern Palsearctic region, frequently known as the Pseudaxine
group, which appears to connect the Axine with the Elaphine
type. Well-known representatives of this group are C. sika (Fig.
128) of Japan, C. mantchwicus of China, and C. taevanus of Formosa.
Fig. 12S. — The Japanese Deer (Cervus sika). From Lord Powerscourt, Proc. Zool. Soc.
1SS4, p. 209.
The antlers have a brow and tres tine, and then a forked beam, of
which the posterior tine is the smaller. The lachrymal vacuity
and fossa are of moderate size ; and the auditory bulla is only
muderately inflated, and quite smooth externally. Tail moderate ;
neck maned. In summer the coat is spotted, but is plain in
winter. A herd of C. sika have been acclimatised in Ireland
by Viscount Powerscourt, at Powerscourt, County Wicklow. A
number of Deer from the Pliocene of Europe, such as C. perrieri
and C. etueriarum, appear to be allied both to the Pseudaxine and
Axine groups.
The Mcqjhine or typical group is at once characterised by the
presence of a bez tine to the antlers (Fig. 129), in which the beam
is rounded, and splits up near the summit into a larger or smaller
21
?22
U KG U LATA
number of snags, often arranged in a cup -like manner. Skull as
in the preceding group. All the species large. The Red Deer,
C. elaphus, which is dark brown in colour, with a light patch on
the rump, inhabits Europe, Western Asia, and Northern Africa — the
so-called Barbary Deer not being specifically distinct. A full-grown
Scotch Stag is fully 4 feet in height at the withers. The antlers are
shed between the end of February and the early part of April ; old
animals shedding earlier than younger ones. The young, which
(as in all the members of the genus except some of the Rusine
species) are spotted, are born at the end of May or the beginning
Fig. 129.— Head of the Wapiti (Cervus canadensis).
of June. The points on the antlers increase in number with the
age of the creature, and when twelve are present it is known in
Scotland as a " royal stag." This number, however, is sometimes
exceeded, as in the case of a pair of antlers, weighing 74 lbs., from
a stag killed in Transylvania, which had forty-five points. The
antlers during the second year consist of a simple unbranched stem,
to which a tine or branch is added in each succeeding year, until
the normal development is attained, after which their growth is
somewhat irregular. Many of the antlers dug up in British peat-
beds (as Fig. 118) are larger than those of living individuals, and
in the cave-deposits of England and the Continent antlers are met
with rivalling those of the AVapiti in size ; these large fossil antlers
CERVin.K 323
probably indicating the ancestral form from which the Red Deer
and several of the allied species are descended.
The North American Wapiti (Cervus annul ensis, Fig. 129), the
Persian Mara! (C. ma/raT), the Kashmir Stag (C. cashmeerianus), as
well as C. affinis of Tibet, are all closely allied to the Red Deer, but
are of larger size, this being especially the case with the first two.
A tine example of the antlers of the Wapiti is shown in the
accompanying woodcut, and exhibits the absence of a cup at the
surroyals, by which this species is distinguished from the Red Deer.
The last, or Damine group of existing Deer includes the Common
and the Persian Fallow Deer. These are readily characterised
by the palmation of the antlers in the region of the surroyals
and the spotted coat. The Common Fallow Deer (C. dama) stands
about three feet in height. The Persian Fallow Deer (C.
mesopotamkfus) is very closely allied, differing only in its slightly
larger size and the form of the antlers, the two breeding together.
The common species, although now kept in English parks, does not
appear to be a native of this country, having probably been
introduced from the regions bordering the Mediterranean. The fur
is of a yellowish-brown colour (whence the name " fallow "), marked
with white spots ; there is, however, a uniformly dark brown variety
found in Britain. The bucks and does live apart, except during the
pairing season ; and the doe produces one or two, and sometimes
three fawns at a birth. The Fallow Deer from the Pleistocene and
Pliocene deposits of the East Coast described under the names of
C. browni and C. falconeri appear to have been closely allied to the
existing species. The remarkable C. verticomis, of the Norfolk
Forest-bed, is regarded as an aberrant member of this group, in
which the antlers are very short and thick, with the brow tine
cylindrical and downwardly curved, and the beam expanded above
the tres tine into a crown with two points.
The extinct Irish Deer (Cervus giganteus), of which the skeleton
is shown in the woodcut (Fig. 130), is the only representative of the
Megacerotine group. The antlers, which may have a span of over
11 feet, are enormously palmated, and have a bifurcated broAV
tine, a small bez tine, and a third posterior tine. The skeleton
measures upwards of 6 feet at the withers. Remains of this
species are especially common in the peat-bogs of Ireland, but are
also met with in Pleistocene deposits over a large part of Europe.
In addition to the forms already mentioned there are many other
fossil species of Cervus, some of which, like the English Pleistocene
C. sedgewicki, cannot be included in any of the existing groups.
There is no conclusive evidence of the existence of any species of
Cervus before the Lower Pliocene period.
Telemetaearpalia. — -This section includes all the Deer of the
New World, together with some Old World forms, and is charac-
324
UNGULATA
terised by retaining the distal extremities of the lateral (second
and fifth) metacarpals. With the exception of Alces, Capreolus,
and Hyclropotes (which are either partly or entirely Old World
types), the vomer is so much ossified as to divide the posterior
bony nares into two distinct orifices (Fig. 132).
Fig. 100. — Skeleton of the Gigantic Irish Deer (Cerv-us giganteus). After Owen.
Rangifer. 1 — The Keindeer, or Caribou as it is termed in North
America, is the sole representative of the genus Rangifer, which
is sufficiently distinguished from all its allies by the presence of
antlers in both sexes. The lachrymal vacuity is small. This
animal is distributed over the northern parts of Europe, Asia, and
America ; the differences which may be observable in specimens from
different regions not being sufficient to allow of specific distinction.
The Reindeer is a heavily built animal, with short limbs, in which
1 Hamilton-Smith, in Griffith's Animal Kingdom, vol. v. p. 304 (1827).
CERVID^E
325
the lateral hoofs are well developed, and the cleft between the
two main hoofs is very deep, so that these hoofs spread out as
the animal traverses the snow-clad regions in which it dwells.
The antlers
J S-
131)
are
large
size,
a bez
as a
(Fi
of very
relative
There is
as well
brow tine, which
are peculiar in
being either
branched or
palmated. In
American
(Caribou),
well as
of
some
the
race
as
in
the specimens
found fossil in
the English
Plei s toe ene
(Fig. 131), one
of the brow
tines is gener-
ally aborted to
allow of the
great develop-
ment of the
other. The
dentition of the Eeindeer is frequently remarkable for the very
small size of the posterior lobe of the last lower molar. Vertebrae :
7, D14, L5, S5, Oil.
The Reindeer has long been domesticated in Scandinavia, and is
of especial value to the Laplanders, whom it serves as a substitute
for the Horse, Cow, Sheep, and Goat. It is capable of drawing a
weight of 300 lbs., and its fleetness and endurance are remarkable.
Harnessed to a sledge it will travel without difficulty 100 miles a
day over the frozen snow, on which its broad and deeply cleft hoofs
are admirably adapted for travelling. During the summer the
Lapland Reindeer feeds chiefly on the young shoots of the willow
Fig. 131. — Skull and antlers of the Reindeer (Rangifer tarandus),
from an English Pleistocene deposit, br, Brow tine ; bz, bez tine.
(After Owen.)
and birch ; and since at this season
migration
to the coast seems
necessary to the well-being of this animal, the Laplander, with his
herds, sojourns for several months in the neighbourhood of the sea.
In winter its food consists chiefly of the so-called reindeer-moss and
other lichens which the animal makes use of its hoofs in seeking
3- 6
UNGULATA
for beneath the snow. The wild Reindeer grows to a much greater
size than the tame breed ; but in Northern Europe the former
are being gradually reduced through the natives entrapping and
domesticating them.
/
The tame breed found
in Northern Asia is
much larger than the
Lapland form, and is
there used to ride on.
Remains referable to
the existing species are
found in the cavern
and other Pleistocene
deposits of Europe.
Akes. 1 — The Elk or
Moose (Akes machlis)
has the same general
distribution as the
Reindeer, and is like-
wise the single existing
representative of its
genus. It is the largest
existing member of the
Fig. 132.— Hinder part of the base of the cranium of the family, attaining SOme-
Virginian Deer (Cariacus virgmianus). From Garrod, Proc. times a hei°'ht of 8 feet
Zool. Soo. 1877, p. 13. ^ ^ withen}> The
antlers (Fig. 133) have neither brow nor bez tine, but form an
enormous basin-shaped palmation, primarily composed of an anterior
and a posterior branch ; their weight may be as much as 60 lbs.
The nasal bones are very short, and the narial aperture of great
size. The Elk is covered with a thick coarse fur of a brownish
colour, longest on the neck and throat. Its legs are long and
its neck short, and as it is thus unable to feed close to the
ground, it browses on the tops of low plants, the leaves of
trees, and the tender shoots of the willow and birch. Its antlers
attain their full length by the fifth year, but in after years they
increase in breadth and in the number of snags, until fourteen of
these are produced. Although spending a large part of their lives
in forests, Elks do not suffer much inconvenience from the great
expanse of their antlers, as in making their way among trees
they are carried horizontally to prevent entanglement with the
branches. Their usual pace is a shambling trot, but when frightened
they break into a gallop. The natural timidity of the Elk
forsakes the male at the rutting season, and he will then attack
whatever animal comes in his way. The antlers and hoofs are his
i Hamilton-Smith, in Griffith's Animal Kingdom, vol. v. p. 303 (1S-27).
cervidj-:
V-l
principal weapons, and with a single blow from the hitter he has
been known to kill a wolf. The female often gives birth to two
fawns, and with these she retires into the deepest recesses of the
forest, the young remaining with her till their third year. The Elk
ranges, but in scanty numbers, over the whole of Northern Europe
and Asia, as far south as East Prussia, the Caucasus, and North
China, and over North America from the New England States
westward to British Columbia. Fossil species are found in the
Pleistocene deposits of Europe.
Cervalces. 1 — A remarkable extinct Deer from the Pleistocene of
North America, described as Cervalces, appears in some respects
Fig. 133.— Head of Elk (Alces machlis).
(although a true Telemetacarpalian) to connect Alces with Cervus.
Thus the palmated antlers are divided into anterior and posterior
branches, but below this division there are two tines aj^parently
corresponding to the bez and posterior tines of Cervus gigunteus
(Fig. 130).
Capreolvs. 2 — Antlers (in the existing species) less than twice the
length of the head, usually with three tines on each. Brow tine
developed from the anterior surface of the upper half of the antler,
and directed upwards. Lachrymal vacuity small. Premaxillaj not
always articulating with nasals. Auditory bullae slightly inflated,
rugose externally. Vertebrae : C 7, D 13, L 6, S 6, C 8. Tail very
short. Glands in fore feet rudimentary ; large in hind feet.
The Roe, or Roe Deer (Capreolus caprea), is a small form dis-
1 Scott, Proc. Ac. Nat. Sci. Philad. 1885, p. 181.
- Hamilton-Smith, in Griffith's Animal Kiwjdom, vol. v. p. 313 (1827).
328
UNGULATA
tributed over Europe and Western Asia, being one of the species
found in the British Isles. The male is somewhat over two feet
in height at the withers, of a dark reddish-brown colour in summer,
with a white patch on the rump. The small antlers are approxi-
mated at their bases, and consist of a rugged beam rising vertically
for some distance, then bifurcating, and the posterior branch again
dividing. The Roe dates from the Pleistocene period. Extinct
Deer from the Continental Pliocene have been provisionally referred
to Capreolus.
Hydropotes. 1 — No antlers in either sex. Lachrymal fossa deep
and short (Fig. 134); lachrymal vacuity of moderate size. Orbits
Fig. 134.— The left lateral view of the skull of a male Chinese Water Deer {Hydropotes
inermis), with the wall of the maxilla cut away to show the root of the canine. I natural
size. (From Sir V. Brooke, Proc. Zool. Soc. 1872, p. 524.)
small and but slightly prominent. Auditory bulla much inflated.
Angle of mandible much produced backwardly (Fig. 134); alveolar
margins of mandible in diastema sharp and everted. Canines of
male very large, and slightly convergent. Vertebne : C 7, D 12,
L 6, S 4, C 10. No tufts
on metatarsals. Foot
glands small in fore feet,
deep in hind ones.
The Chinese Water
Deer (H. inermis) is the
sole representative of this
genus. In the absence of
antlers and the large can-
ines of the male it resem-
bles Moschus, although very
Fio. 135.-Upper surface of the brain of Hydropotes different ^ Other respects.
inermis. (From Garrod, Proc. Zool. Soc. 1877, p. 792.) Thus the brain (Fig. 135)
has the hemispheres much
convoluted, as in other Cervince, and approximates to that of Puclua ;
1 Swinhoe, Proc. Zool. Soc. 1870, p. 90.
CERVID^E 329
while the placenta and viscera likewise agree with those of the true
Deer. In the total absence of any ossification of the vomer to
divide the posterior nares Hydropotes resembles Capreolus and differs
from all the following genera. The Chinese Water-Deer is nearly
of the same size as the Indian Muntjac. It has short legs and a
long body, the hair covering the latter being of a light reddish-
brown. It is a remarkably prolific animal, differing from all other
Deer in producing five or six young at a time.
The mandible of a ruminant from the Middle Miocene of Gers
in France, described under the name of Platyprosopus, presents such
a marked remblance to Hydropotes in the form of the angle as to
suggest a more or less intimate affinity.
Cariacus. 1 — Skull (Fig. 132) with the vomer dividing the
posterior nares into two distinct chambers ; premaxillae not reach-
ing nasals. Antlers never greatly exceeding the length of the head.
Lachrymal vacuity very large, and lachrymal fossa small. Auditory
bulla? slightly inflated. Vertebras: C 7, D 13, L 6, S 4, C 13. Tail
long or short. Colour uniform in adult.
This genus, which agrees with the Reindeer in the division of
the posterior nares by the ossified vomer, comprises a number of
species confined to the New World, none of which attain very
large dimensions, and the antlers of which are relatively smaller
than in the existing species of Cervus. The genus may be divided
into groups.
The typical Cariacine group, as represented by C. virginianus,
has well -developed antlers, with a short brow tine rising from
the inner side of the beam, and directed upwards, and several
branches ; a long tail ; and no upper canines. In this species, as
well as in C. mexicanus and other forms, the antlers do not divide
dichotomously, and the lachrymal fossa is of moderate depth. The
Mule Deer {C. macrotis) of North America is distinguished by the
dichotomous branching of the antlers and the deeper lachrymal
fossa. The Virginian Deer is somewhat smaller than the Fallow
Deer, and of a uniform reddish -yellow colour in summer, and light
gray in winter.
The Blastocerine group of South America is represented by C.
paliulosus and C. campestris, and has dichotomous antlers, with no
brow tine, and the posterior branch the larger, a short tail, and no
upper canines. The Furciferine group includes C. chilensis and
ft antisiensis, confined to western South America. The antlers are
not longer than the head, with a large anterior tine curving forwards
at right angles to the simple posterior one. Auditory bulla? slightly
inflated, and rugose. Upper canines may be present. The species
are of medium size, ft clavatus, of Central America, while resem-
bling this group in the characters of the skull and the arrangement
1 Gray, Proc. Zool. Soc. 1850, p. 237.
33° UNGULATA
of the hair on the face, agrees with the next one in having simple
spike-like antlers.
The South American Coassine group comprises the small forms
known as Brockets, in which the antlers form simple spikes not
exceeding half the length of the head. Some six species are known.
Remains of Cariacus, mostly or entirely referable to existing
species, are of common occurrence in the Brazilian cave-deposits.
Blastomeryx, of the Pliocene of North America, is believed to be an
allied type.
Puclua. 1 — Antlers in the form of minute simple spikes.
Distinguished from the Coassine group of Cariacus by the articulation
of the premaxillse with the nasals (as in the Furciferine group),
and the coalescence of the ectocuneiform with the naviculo-cuboid.
as well as by various external characters. No upper canines. Re-
presented only by the very small P. humilis of the Chilian Andes.
Extinct Genera. — In the European and other Tertiary deposits
several genera of extinct Cervidce occur, of which the more important
may be briefly mentioned. Amphitragulus, of the Lower Miocene
of the Continent, has four lower premolars, brachydont molars, and
no antlers ; the largest species being somewhat bigger than the
Musk-Deer. The closely allied Palceomeryx (Dremotherium or Micro-
meryx) generally has but three lower premolars, and the brachydont
upper molars (Fig. 122), like those of Amphitragulus, w r ant the small
accessory inner column 2 found in modern Deer. In P. feignouxi, of
the Lower Miocene, the lateral metacarpals, although slender, were
complete, and the males had large canines, but no antlers.
P. furcatus, of the Middle Miocene, had small antlers, and the canines
appear to have been reduced in size. This genus, besides being repre-
sented in the European Miocene, also occurs in the Pliocene of India
and China ; some of the species being as large as the Red Deer.
Family Giraffid.e.
In the existing genus the frontal appendages consist of a pair
of short, erect, permanent bony processes placed over the union of
the frontal and the parietal bones, ossified from distinct centres,
though afterwards ankylosed to the skull, covered externally with
a hairy skin, present in both sexes, and even in the new-born animal.
Anterior to these is a median protuberance on the frontal and
contiguous parts of the nasal bones, which increases A\dth age, and
is sometimes spoken of as a third horn. Skull with a lachrymal
vacuity. No upper canines. Molars brachydont, with rugose
1 Gray, Proc. Zool. Soc. 1850, p. 242.
2 This accessory column is shown in the figure of the molar of Boselaphvs on
p. 311.
GIRAFFID&
33i
enamel : the upper ones having no inner accessory column. Lateral
digits entirely absent on both tore and hind feet, even the hoofs
not developed. Humerus with double bicipital groove. Vertebrae :
Fig. 136. — The Giraffe (Giraffa camelopardalis).
C 7, D 14, L 5, S 3, C 20. Gall-bladder generally absent. Male
reproductive organs and placenta of a Bovine type. Dentition :
* i> c t> P f , m f .
Giraffa. 1 — The Giraffe (G. camelopardalis) is the sole existing
representative of the genus, now confined to the Ethiopian region.
1 Zimmermann, Geograph. Gcschichtc, vol. ii. p. 125(1780).
332 UN GU LATA
In addition to the characters noticed above, the Giraffe is
characterised by its great size and peculiar proportions ; the neck
and limbs being of great length, and the back inclining upwards
from the loins to the withers.
To produce the extremely elongated neck the seven cervical
vertebrae are proportionately long, which gives a somewhat stiff and
awkward motion to the neck. The ears are large, the lips long and
thin, the nostrils closable at the "will of the animal, the tongue very
long and extensile, and the tail of considerable length, with a large
terminal tuft. An adult male may have a total height of 16 feet.
The coloration consists of large blotches of darker or lighter chestnut-
brown on a paler ground, the lower limbs and under parts being of
a uniform pale colour. The Giraffe feeds almost exclusively on the
foliage of trees, showing a preference for certain varieties of mimosa,
and for the young shoots of the prickly acacia, for browsing on
which its prehensile tongue and large free lips are specially adapted.
It is gregarious in its habits, living in small herds of about twenty
individuals, although Sir S. Baker, who hunted it in Abyssinia,
states that he has seen as many as a hundred together.
Fossil sj)ecies of Giraffa occur in Pliocene deposits over Greece,
Persia, India, and China, thus affording one of many striking instances
of the former wide distribution of the generic types now confined to
the Ethiopian region.
Allied Extinct Types. — The Pliocene deposits of many parts of the
Old World yield remains of a number of large Ruminants which show
such evident signs of affinity with the Giraffe that it is difficult to
draw up a definition by which they can be separated in characters of
family value from that genus. On the other hand, some of these
forms approximate in the characters of the skull to some of the
brachydont members of the Bovicke, although it is quite clear from
the nature of the cranial appendages that they cannot be included in
that family. All these forms have brachydont molars, with rugose
enamel, like those of the Giraffe ; while several of them have limb-
bones approximating to those of the latter — the humerus, when
known, having a double bicipital groove. The nature of the cranial
appendages (when present) is not fully understood, but it appears
that in some cases these approximated more to the type of an antler
than to that of a horn ; although, from the absence of a " burr," they
appear never to have been shed. A gradual diminution in the
length of the limbs and neck can be traced from the more Giraffoid
to the more Bovoid forms of this extinct group ; and it is manifest
that if these animals be included in the Gintffidce the definition of
that family as given above must be somewhat modified. Only brief
mention can be made of the more important genera.
The imperfectly known Vishmitherium, of the Pliocene of India
and Burma, seems to make the nearest approach to the Giraffe, but
ANTILOCAPRID.K 333
the limbs and cervical vertebrae were decidedly shorter, although of
a similar slender type Helladotherium, of the Pliocene of Greece
and India, is represented by a species of considerably larger size
than the Giraffe, with no appendages or lachrymal vacuity to the
skull, and with shorter and stouter limbs and neck
Hydaspitherium, Bramatherium, and Sivatherium are Indian genera,
characterised by the presence of large palmated and antler-like
cranial appendages, varying considerably in arrangement. The
former genus has a large lachrymal vacuity which is absent in the
two latter. In the first and second genera all the appendages rise
from a common base ; but in Sivath riwm there is a pair of simple
horn-like projections on the orbits in addition to the posterior
palmated antlers. Sivatherium was an animal of huge bulk, being
the largest known representative of the Pecora.
Another apparently allied type is Samotherium, of the Pliocene
of the Isle of Samos, which appears also to have some affinity with
the Antelopes. The skull is nearly as large as that of the Giraffe,
and is of the same elongated shape, although depressed between the
conical horn-cores, which rise vertically above the orbits, and without
a median bony prominence on the frontals. The horn-cores form
mere processes of the frontals. The diastema and the mandibular
symphysis are shorter than in the Giraffe, and the latter is less
deflected. The teeth, although larger, are almost indistinguishable
from those of the Giraffe, the only well-marked difference being that
the last lower premolar has a double in place of a single postero-
internal column.
Family Antilocaprid^:.
Closely allied to the Bovidce, but the horns deciduous and branched.
Antilocapra. 1 — The Prongbuck, or Prong-horned Antelope
(Antilocapra americana), as the single existing member of this family
is called, is an animal of nearly the same size as the Fallow Deer,
but of a lighter and more graceful build. It is an inhabitant of the
prairies of North America, where it is one of the few representa-
tives of the Cavicorn Pecora. The bony horn-cores are unbranched,
and form vertical, blade-like projections immediately above the
orbit. The horns themselves are compressed, and nearly one foot in
length, having a gentle backward curvature, the short branch arising
somewhat above the middle of its height, and inclining forwards.
AVhen the horn is about to be cast off it becomes loosened, and a
new one is formed upon the bony core beneath it. The ears are
long and pointed, and the tail is short. The neck has a thick mane
of long chestnut-coloured hair, and there is a white patch on the
rump.
1 Ord. Joum. dc Physique, vol. lxxxvii. p. 149 (1818).
-> -> 4
jo4
UNGULATA
Family Bovid^e.
Frontal appendages, when present, in the form of non-deciduous
horns. Molars frequently hypsodont. Usually only one orifice to
the lachrymal canal, situated inside the rim of the orbit. Lachrymal
bone almost always articulating with the nasal. Canines absent in
both sexes. The lateral toes may be completely absent, but more
often they are represented by the hoofs alone, supported sometimes
by a very rudimentary skeleton, consisting of mere irregular
nodules of bone. Distal ends of the lateral metapodials never
present. Gall-bladder almost always present. The number of
cotyledons in the placenta generally varies from 60 to 100 ; whereas
in the Cervidce the number is usually from 5 to 12, Capreolus and
Hydropotes having the fewest. In Giraffa the number is upwards of
180. The nature of the horns and horn-cores has been already
explained ; in the majority of genera these appendages are present
in both sexes, although much larger in the male (see p. 310).
The Bovidce, or hollow-horned Ruminants (Cavicornia), form a
most extensive family, with members widely distributed through-
out the Old World, with the exception of the Australian region ;
but in America they are less numerous, and confined to the Arctic
and northern temperate regions, no species being indigenous either
to South or Central America. There is scarcely any natural and
well-defined group in the whole class which presents greater
difficulties of subdivision than this ; consequently zoologists are as
yet very little agreed as to the extent and boundaries of the genera
into which it should be divided. For the present the genera
provisionally adopted may be arranged under a number of sections
or groups, which some writers regard as subfamilies. The series
may be commenced with the Antelopes, the greater number of which
are now characteristic of the Ethiopian region.
Alcelaphine Section. — Includes large African Antelopes, of which
the type genus ranges into Syria ; generally chai'acterised by their
great height at the withers as compared with the rump. Skull with
large frontal sinuses, extending into the horn-cores, and the horns lyre-
shaped or recurved, and more or less approximated at the base. No
large pits at apertures of supraorbital foramina in frontals ; upper
molars hypsodont and narrow. Horns in both sexes. General
colour mostly uniform.
Alcelaphus. 1 — If Damcdis be included, this genus is represented
by some nine or ten living species. Head more or less long and
narrow, with the muffle moderately broad and naked. Nostrils
approximated, edged with stiff hairs. Horns compressed and ringed
at the base, more or less lyrate, and bent back at the tips. Hoofs
small. Tail of moderate length, and heavy. Two mamma?.
1 Blainville, Bull. Soc. Philom. 1816, p. 75.
B0V1D.K
335
In the typical forms, such as the Bubaline Antelope (A. bviba-
liinis), the Harte-beest (A. mama, Fig. 137), and the Tora Antelope
(A. tora, Fig. 138), the horns, which present the peculiar curvature
shown in the figures, are situated on a crest at the vertex of the skull,
and the facial portion of the cranium is greatly elongated. The Harte-
beest) which is found throughout Central and Southern Africa,
stands nearly 5 feet high at the withers, and is a somewhat ungainly
looking animal, with short hair, which is grayish-brown above
and nearly white beneath. In the Pliocene of the Siwalik Hills in
Northern* India there occur remains of an Alcelaphus (A. palctindicus)
Fig. 137.— The Harte-beest (Alcelaphus caarna).
in Avhich the skull had the long facial portion characteristic of the
typical group, while the horns approximate to those of the
Bontebok. The Blessbok (A. albifrons) and Bontebok (A. pygargus),
belonging to the genus Damalis of many authors, have the facial
portion of the skull shorter, the horns situated more in advance of
the plane of the occiput, and inclining regularly backwards. Of the
Blessbok Mr. C. J. Anderson observes that "it is of a beautiful
violet colour, and is found in company with black Wildebeests and
Springboks in countless thousands on the vast green plains of short
crisp, sour grass occupying a central position in South Africa. Cattle
and horses refuse to pasture on the grassy products of these plains,
which afford sustenance to myriads of this Antelope, whose skin
emits a most delicious and powerful perfume of flowers and sweet-
336
UNGULATA
smelling herbs." Since the time this was written these Antelopes
have been greatly reduced in number. A. (Damalis) hunteri, from
East Africa, appears to be allied to A. senegalensis, but in the more
elongated facial portion of the skull approximates to the Harte-beest,
and thus confirms the view that Damalis should not form a distinct
genus.
Fig. 13S.— Head of Alcelaphus torn. From Sclater, Proc. Zool. Soc. 1873, p. 762.
Connocluetes. 1 — Head short and massive, with the muffle very
broad and bristly. Nostrils widely separated, hairy within. Horns
on the vertex of the skull,- immediately over the occiput, approxi-
mated at base, cylindrical, bent outwards, and recurving upwards
at the tip. Extremities of premaxillae much expanded laterally,
and firmly ankylosed. Vertebras : C 7, D 14, L 6, S 4, C 16.
Hoofs very narrow. Tail very long, covered throughout with long
hairs. Four mamma?. Two species, C. taurina and C. gnu (Fig. 139),
1 Lichtenstein, Berlin Ges. Natuforsch. Freundc Magazin, vol. vi. pp. 152, 165
(1814).
BOVIDjE
337
both from South Africa. The former, or Brindled Gnu, is distin-
guished by the absence of long hair on the face, the black (instead
of white) tail, and the presence of dark vertical streaks on the
shoulders ; it is never found to the south of the Orange River.
The White-tailed Gnu stands about 4 feet 6 inches at the
withers. These animals were formerly found in large herds, and
are remarkable not only on account of their peculiar form, but also
for their grotesque actions when alarmed. Some interesting
observations have recently been published upon the mode of
Jfe?= ~
Fig. 139.— The White-tailed Gnu (Connochwtes gnu).
development of the horns of the Gnu, 1 from which it appears that
in very young individuals the horns are straight and divergent,
situated some distance below the vertex of the head, and separated
by a wide hairy interval. These young horns form the straight
tips of those of the adult, the basal downwardly curved portion
bring subsequently developed. In the fully adult animal the base
of the horns forms a helmet -like mass on the forehead which
completely obliterates the hairy frontal space of the young.
Cephalophine Section. — Small or medium-sized African and
Indian Antelopes, with simple horns present only in the males, a
more or less elongated suborbital gland, a lachrymal depression
in the skull, and square-crowned upper molars (Fig. 140). Lateral
hoofs well developed.
1 F. E. Blaauw, Proc. Zool. Soc. 18S9, p. 2.
22
338
UNGULA TA
< 'ephalophus. 1 — One pair of horns, arising far back on the frontals,
conical, short, angulated at the base, and erect or recurved. Sub-
orbital gland opening in the form of a slit, or as a row of pores.
Auditory bulla divided by a distinct septum. Muffle large and moist.
Tail very short. Head tufted. Upper molars of larger species with
an accessory internal column. Dorsal vertebrae fourteen in number.
Some sixteen species, confined to southern and tropical Africa.
The Duikerboks, as the members of this genus are called, are
among the most graceful of the African Antelopes, the smallest
species not being larger than a rabbit. The West African C.
sylvicultor and C. longiceps are the largest species.
Tcfraceros. 2 — Two pairs of conical horns, of which the anterior
are much the smaller. Suborbital gland elongated, and lachrymal
fossa very large. Upper molars
(Fig. 140) without accessory internal
column. One existing Indian species
(T. qvadricornis).
The Four-horned Antelope is found
throughout the peninsula of India in
jungle. The general colour is brown,
lighter beneath and on the inside of
the limbs. Remains of this species
are found fossil in the cave-deposits
of Madras, and a small Ruminant from
the Pliocene of the Siwalik Hills has
fig. 140. -Palatal and outer aspects of been Provisionally referred to this
the three right upper premolars and first geilUS.
mi ilar of the Four-horned Antelope (Tetra
ceros guadricornis). From the Palceon
tologia Tndica.
Cervicaprine Section. — Small or
large Antelopes now confined to the
Ethiopian region, with horns present
only in the males, lachrymal vacuity generally large, more or less
distinct pits at the apertures of the supraorbital foramina in the
frontals, and narrow upper molars in which there is no accessory
internal column.
Neotragus? — Distinguished from the next genus by having the
crown of the head tufted, muzzle hairy, premaxillse long and
reaching the lachrymals, nasals very short, mesethmoid much
ossified, third lobe of last lower molar either absent or very small,
and the hinder lobe of the corresponding upper molar much reduced.
Three species, Salt's Antelope {N. saltianus), from Abyssinia,
and also N. lirki and A r . danwmisis ; the two latter having a small
third lobe to the last molar. Writing of the first-named species,
1 Hamilton-Smith, in Griffith's Animal Kingdom, vol. iv. p. 258 (1827).
Taken to include Grimmia, Terphone, etc., of Gray.
2 Leach, Trans. Linn. Soc. vol. xiv. p. 524 (1823).
3 Hamilton-Smith, in Griffith's Animal Kingdom, vol. iv. p. 269 (1827).
BO VI DAL 339
Mr. W. T. Blanford 1 observes that "the Beni-Israel, or Orrirdig-dig,
one of the smallest Antelopes known, abounds on the shores of
the Red Sea and throughout the tropical and subtropical regions of
A.byssinia. It is occasionally, but rarely, found at higher eleva-
tions : I heard of instances of its being shot both at Serafie and
Dildi, but it is not often seen above about 6000 feet. It inhabits
bushes, keeping much to heavy jungle on the banks of water-courses,
and is usually single, or in pairs, either a male and female or a
female and young being found together; less often the female is
accompanied by two young ones, which remain with her until
full grown."
Nanotragvs. 2 — Horns small, parallel with frontals, and rising
immediately above postorbital process of frontals, in front of the
front o- parietal suture. Lachrymal fossa very large, suddenly
descending in front of the orbit, and extending on to the
maxilla ; lachrymal vacuity small. Auditory bulla large and
smooth, without internal septum. Nasals of moderate length.
Crown of the head smooth ; naked part of muffle small ; aperture
of suborbital gland small. Lateral hoofs small or absent. Nine
species. 3
The typical species is the Royal Antelope (X. pygmceus) of
Guinea, the smallest existing representative of the Pecora. This
species, together with N. moschatus and A r . tragulus have no lateral
hoofs, or tufts on the knees. In the Scopophorine group, comprising
N. scoparia, N. montanus, and N. hastatus, both these appendages
are present ; while in the Oreotragine group (A 7 ", melanotis and
N~. oreotragus) the former are present and the latter absent.
Pelea. 4 — Horns rather small, compressed, upright, scarcely
diverging, and placed immediately over the orbits. No suborbital
gland, nor lachrymal fossa ; premaxillse not reaching nasals. Tail
short and bushy. Colour uniform. One species — the Rehbok
(P. capreola), South Africa, is nearly of the size of a Fallow Deer,
although more resembling a Chamois in build and habits. The
colour is of a uniform light gray. This animal inhabits bare
rocky districts, and thus differs widely from the Water-buck and
its allies.
Cobus. 5 — Large Antelopes, with the horns large, elongate, sub-
lyrate, and ringed at the base, and with rudimentary suborbital
glands. Skull with a deep frontal hollow, no lachrymal depression,
1 Geology and Zoology of Abyssinia, p. 268.
3 Sundevall, Kongl. Vetensk. Akad. Handl. for 1844, p. 191. Taken to
include Calotragus, Scojjophonts, Nesotragus, Pediotragus, and Oreotragus of Gray.
3 See V. Brooke, Proc. Zool. Soc. 1872, pp. 642 and 875.
4 Gray, Cat. Ungulate Mamm. Brit. Mus. p. 90 (1852).
5 Andrew Smith, Illustrations of Zoology of South Africa, Xo. 12 (1840),
" Kobus." Is taken to include Adenota and Onotragus of Gray.
34° UNGULATA
large lachrymal vacuity, and the premaxillse reaching the very long
nasals. Tail long, with a ridge of hair above, and slightly tufted
at the end. Colour uniform. Six species, African.
The Antelopes of this genus are water -loving animals, the
Water-buck (C. ellipsiprymnus) and the Singsing (C. defassus) being-
well-known examples. Both these species are much alike, standing
as much as 4 feet 6 inches at the withers. The Water-buck of
South and Eastern Africa is characterised by the coarseness of
its long hair ; while in the Singsing of West and Central Africa
the hair is remarkably fine and soft. Fossil Antelopes from the
Pliocene of India are referred to Cobus. Helicophora, from the
Lower Pliocene of Attica, is regarded as allied to Cobus, but it has
no distinct supraorbital pits.
Cervicapra. 1 — An allied South African genus in which the tail is
short and bushy and the premaxillae do not reach the nasals. Three
species.
The Reitbok (C. arundineum) is of a grizzly ochre colour ; it
stands nearly 3 feet in height, and has horns about 1 foot in
length. The Nagor (C. redunai) is about 6 inches shorter, with
horns of half the length, and fulvous brown above and white
below ; the West African C. bohor being rather larger.
Antilopine Section. — A large group of moderate - sized or
small Antelopes, most abundant in the deserts bordering the
Palsearctic, Oriental, and Ethiopian regions. Horns generally
compressed and lyrate, or recurved, or cylindrical and spiral,
ringed at base, sometimes present in both sexes. Skull with large
pits at apertures of supraorbital foramina of frontals, and generally
a distinct lachrymal fossa. Molars of upper jaw narrow, without
inner accessory column, and resembling those of the Sheep and
Goats. Tail moderate, compressed, hairy above.
Antilope. 2 — Horns, present only in the male, long, cylindrical,
subspiral, and diverging. Suborbital gland large, with a somewhat
linear opening ; lachrymal depression of skull very large, and a
small lachrymal fissure. Glands in the feet ; lateral hoofs present.
One species, India.
The well-known Black-buck (A. cervicapra) is found on open
plains all over India, except in lower Bengal and Malabar. Old
males are deep blackish-brown in colour on the back and sides and
the outer surfaces of the limbs, the under parts and inner surfaces
of the limbs white, and the back of the head, nape, and neck
yellowish. Young males and females are fawn-coloured above.
Very large herds are seen in the plains about Dehli and Mattra,
which are said in some instances to reach to thousands. Horn-
cores are found in the Pleistocene deposits of the valley of the
1 De Blainville, Bull. Soc. Philom. 1816, p. 75. Syri. Eleotragus.
- Pallas, Spicilegia Zoologica, vol. i. p. 3 (1767).
BO 1 1D.E 341
Jumna which cannot be distinguished from those of the existing
species.
AHpyceros. 1 — Horns compressed, lyrate, and wide - spreading ;
present only in male. No suborbital gland, or lachrymal depression
in the skull. No lateral hoofs. Two species; one from South and
the other from West Africa.
The Palla {JE. melampus) is a large Antelope standing over
3 feet high at the withers, and readily distinguished by its dark red
colour, gradually shading to white below. It is usually found on
or near hills in herds of from twenty to thirty. JS. petersi is
from the Congo.
Saiga. 2 — Nose very large, convex, and inflated. Supraorbital
gland present. Lachrymal fossa of skull small, and fissure absent ;
narial aperture very large ; nasals extremely short ; supraorbital
pits rather small. Horns yellow, lyrate, of moderate length ;
present only in male. Vertebrae : C 7^ 13, L 6, S 4, C 10. One
species, Eastern Europe and "Western Asia.
The Saiga (S. tartarica) is a clumsily built and somewhat
sheepdike Antelope inhabiting the steppes ; it occurs fossil in the
Pleistocene of France and England.
Pantholops. s — Allied in the characters of the head and skull to
Saiga, but the nose less convex, the nostrils of the male more
swollen, and the horns of that sex black, very long, compressed,
and lyrate ; those of female very short. One species, Central Asia.
The Chiru (P. hodgsoni) inhabits the highlands of Western Tibet
and Turkestan. In the former area it generally goes in small herds
of from three to six, and in the summer may be found grazing in
early morning on the level spaces frequently found in the river
valleys at elevations of about 15,000 feet. It is excessively shy
and difficult to approach. The large size of the narial aperture in
the skull of Chiru is suggestive of a connection with respiration at
a high altitude, but this appears to be negatived by the occurrence
of the same feature in the Saiga.
Gazella. 4 — Delicately built and sandy -coloured Antelopes, with
lyrate or recurved horns, which may be absent in the female, and
are always smaller and simpler in that sex than in the male. Skull
with moderate lachrymal fossa, and a distinct lachrymal fissure.
Vertebrae : C 7, D 1 3, L 6, S 4, C 1 4. Suborbital gland frequently
small, and covered with hair. Face with a white streak running
from the outer side of the base of each horn nearly down to the
upper end of each nostril, cutting off a dark triangular central
1 Sundevall, Kongl. Vetensk. Akad. HandU for 1845, p. 271.
- GiSLy,-L!st Mamm. Brit. Mas. p. 160 (1843).
3 Hodgson, Proc. Zool. Soe. 1834, p. 81.
4 De Blainville, Bull. Soe. Philom. 1816, p. 75. Is taken to include Procapra
and Tragops.
342 UNGULATA
patch, and bordered externally by a diffused dark line (see Fig.
121, p. 310). The Gazelles, of which there are some tw r enty-
four existing species, are typically Palsearctic desert forms, the
Springbok (G. euchori) being an outlying South African species.
G.' picticaudata and G. gutturosa are respectively found in "Western
Tibet and Mongolia, the former at great elevations. The
majority of the Gazelles do not exceed 30 inches in height,
although G. mohr is 36. Sir Victor Brooke classifies 1 the Gazelles
as follows : —
A. No stripe on back ; three lower premolars.
a. "White of rump not encroaching on the fawn of the haunches.
I. Female with horns.
1. Horns lyrate or sublyrate — G. dorcas, G. isabella,
G. rufifrons, G. Icevipes, G. tilonura, G. naso.
2. Horns non-lyrate — G. cuvieri, G. leptoceros, G. spekei,
G. arabica, G. bennetti, G. fuscifrons, G. muscatensis.
II. Female without horns.
G. subgutturosa, G. gutturosa, G. picticaudata.
b. "White of rump projecting forwards in an angle into the fawn
colour of the haunches. Horns in both sexes.
G. da/ma, G. mohr, G. soemnnrriinji, G. granti (Fig. 121),
G. tliomsoni.
B. A white stripe down the back, two lower premolars. Horns in
both sexes. — G. euchore.
The East African G. imlleri is an aberrant species, in which the
females are hornless, which has been made the type of the genus
Lithocranius. It is characterised by the extreme density of the
horns and skull, the slenderness of the mandible, and the small
size of the cheek-teeth, the upper molars being relatively broader
and lower than usual. The cranium is remarkable for the short-
ness of its facial portion, the large size and production backwards
of the supraoccipital, and for the circumstance that the long
basicranial axis is nearly parallel with the plane of the palate.
Fossil species of Gazclla are found in the Pliocene and Pleistocene
deposits of Europe and India. G. deperdita (brevicornis), of the
Lower Pliocene of France and Greece, appears to be a generalised
species in which the lower molars frequently have accessory
columns, traces of which are found in some of the existing forms.
Hippotrugine Section. — Includes very large African Antelopes,
with long horns, present in both sexes, which are placed over or
behind the orbit, and are either recurved, straight, or subspiral.
Skull with no distinct pits at apertures of supraorbital foramina in
frontals, no lachrymal fossa, and only a small lachrymal fissure.
No suborbital gland. Tail long, cylindrical, and tufted at the end.
1 Proc. Zool. Soc. 1873, p. 537. Three species subsequently described are
here added to the list.
B( > VI DAL 343
Upper molars extremely hypsodont, very broad, and with large
accessory columns, thus closely resembling those of the Oxen.
Sonic authorities divide this section into two. In the Pliocene it
occurs in India and Europe.
Hippotragus.* — Horns stout, rising vertically from a crest over
the orbil at an obtuse angle to the plane of the nasals, then
recurved : lachrymal fissure in some instances almost obliterated.
Neck with an erect recurved mane. Tail very distinctly tufted.
Four species, tropical Africa and south to the Cape.
The Sable Antelope (II. niger) is one of the best-known
examples of this genus, occurring in South and East Africa. It
stands upwards of 4| feet in height at the withers, and, except
for some white streaks on the face and the whole of the under
surface of the body, is of a black colour. The Blaubok (H. leuco-
pha us) is distinguished by the glaucous hue of the hair. The other
specie- are the Eijuine Antelope (H. eguinus) and Baker's Antelope
(H. bakeri) from the Sudan, both closely allied, but the latter
distinguished by its pale fulvous colour, pencilled ears, and black
stripes on the shoulder.
Skulls of fossil Antelopes from the Pliocene of India have been
referred to Hippotragus (II. sivalensis), and Sir V. Brooke suggests
that the European Pliocene Antilope recticornis is not generically
separable.
Oryx? — Horns long, slender, nearly straight or somewhat
recurved, rising behind the orbit, and inclining backwards in the
plane of the nasals ; lachrymal fossa distinct. Nape maned ; tail
long, and more haired than in Hippotragus. Four species, ranging
over all the African deserts to Arabia and Syria.
The Gemsbok (0. gazella, Fig. 141), is a South African species
characterised by its straight horns, the presence of a tuft of
hair on the throat, as well as by the large patches and stripes
of black on the head, back, limbs, and flanks. It stands nearly
4 feet in height at the shoulder, and the horns are 2 feet 9
inches in length. The colour of the upper part of the body is
a rusty gray, and of the under part white, while these are separ-
ated from each other by a well-defined black band on either side.
These bands unite on the breast, and are continued as a single
black band until reaching the lower jaw, where they again divide
and form two transverse bands on the head, terminating at
the base of the horns. The head otherwise is white, as also are
the limbs, wdth the exception of the thighs, which are black.
The Gemsbok generally goes in pairs, or in small herds of three
or four. The Beisa (0. beisa) of Abyssinia is distinguished by
the absence of the tuft of hair on the throat. Writing of this
1 Sunclevall, Kongl. Vetcnsk. Akacl. Handl. for 1844, p. 196.
2 De Blainville, Bull. Soc. Philom. 1816, p. 75.
344
UN GU LATA
species in his Geology and Zoology of Abyssinia, Mr. W. T. Blanford
observes that " the appearance of a herd of Oryx is very imposing.
They are some of the most elegant and symmetrical of animals, the
motions being those of a wild Horse rather than of an Antelope.
Their favourite pace appears to be either a steady quick Avalk or a
trot ; they rarely break into a gallop unless greatly alarmed.
When frightened they dash off, sometimes snorting and putting
""~ ; — VVOOCV ^tl^^— -^ — ^ — ^J ~ ~~i - —- ~^ ~ *~TTtf/rtSf>T*S*£ATHS(—^~
Fig. 141. — The Gemsbok (Oryx gazcUa).
their heads down as if charging, raising their long tails, and look-
ing very formidable. They are wary animals, though far less so
than some other Antelopes. It is said that they frequently attack
when wounded, and their long straight horns are most deadly
weapons." The Arabian Beatrix Antelope (0. beatrix) is a much
smaller animal, with the black markings confined to the head, fore
limbs, and flanks. Finally, the Leucoryx (0. leucoryx) of North
Africa, while agreeing in size with the Beatrix, differs by its curved
horns and uniform coloration.
The extinct Palceoryx, of the Lower Pliocene of Europe and the
Isle of Samos, appears to have been an ancestral form of Oryx, said
to show some signs of affinity with Hippotragus.
liOVJJUC 345
Addax? — Horns with the same inclination as in Oryx, Imt with
;i slight spiral twist. No mane on nape, but a slight one on the
throat. Hoofs rounded. One species (./. nusinwirii/tifus), from North
Africa and Arabia, the colour of which is nearly white.
Tragelaphine Section. — Includes large, so-called Bovine, Ante
lopes now mainly characteristic of the Ethiopian region, but with
one Oriental genus. Horns usually present in the male only (if
developed in the female smaller), with a more or less distinct ridge
in front, and usually twisted spirally, the front ridge twisting
out wa ids from the base of the horn. Skull without lachrymal
Eossa, but with a large or small lachrymal fissure; usually large
pits at the apertures of the supraorbital foramina on the frontals ;
premaxilhe reaching nasals. Muffle large and moist ; nostrils
approximated. Molars hypsodont or brachydont. Vertical white
stripes frequently present on the bocty.
a. Hind limbs much shorter than the fore. Horns behind the orbit,
.<horf, conical, faintly angulated. Nose bovine. Body without
vertical stripes. Molars (Fig. 123, p. 311) hypsodont, with
a large accessor;/ column in those of the upper jaw. One
Oriental genus.
Bosel aphis. 2 — The one genus of this subsection is represented
only by the well-known Nilghai (B. tragocamelus) of India. The
male stands over 4 feet in height at the shoulder, with horns
about 8 inches in length ; the hornless female being about one
third smaller. Both sexes have a short erect mane, and the male
has also a tuft of hair upon the throat. When adult the sexes
are very different in colour, the male being of a dark iron gray
or slate colour, approaching black on the head and legs, while
the female and young are of a bright light brown or fawn colour.
In both male and female at all ages the lips, chin, and under parts,
as well as two transverse stripes on the inner sides of the ears and
rings on the fetlocks, are white, and the mane and tip of the tail
black. The Nilghai is one of the few Antelopes occurring in India,
where it is found from near the foot of the Himalaya to the south
of Mysore, though rare to the north of the Ganges and also in the
extreme south. It is most abundant in Central India, and does not
occur in Assam or the countries to the east of the Bay of Bengal.
It frequents forests and low jungles, though often found in toler-
ably open plains, associating in small herds. One, or very often
two, young produced at a birth. Fossil remains of species of this
genus occur in the Pleistocene and Pliocene deposits of India.
b. Fore and hind limbs equal. Horns long, and spirally twisted.
Nose cervine, and aperture of suborbital gland very small.
1 Rafinesque, Anal. Nat. 1815, p. 56.
- De Blainville, Bull. Soc. Philom. 1816, p. 75. Syn. Portax, Hamilton-
Smith.
346
UNGULATA
Body generally striped. Molars Irachydont, those of the
upper jaw in existing forms with a small inner accessory
column. Three existing Ethiopian genera.
Tragelaphus. 1 — Female hornless. Horns of males (Fig. 142) over
Fig. 142.— Head of Tragelaphus gratus. From Sclater, l'roc. Zool. Soc. 1SS3, p. 36.
orbit, with one or two spiral turns, obscurely ridged,- the posterior
ridge being more developed than the anterior. Skull with small
supraorbital pits, very small lachrymal fissure, and no deep inter-
cornual depression in the frontals. Neck maned or smooth. Hoofs
short or long. Coloration usually brilliant, differing markedly in
the two sexes, and the white bands on the body, when present,
numerous and distinct. Seven species.
1 De Blainville, Bull. Soc. Philom. 1816, p. 75. Includes Euryceros, Gray.
BO VI P.K
347
The Harnessed Antelopes are among the handsomest of the
whole -roup. The small Guib ('/'. scriptus) is not larger than a
Goat, but T. angasi is 3 feet 1 inches in height at the shoulder. In
T. scriptus, '/' angasi, ami T. euryceros, the two sexes differ in colour,
the body is marked by white stripes descending from a white dorsal
streak, and the hoofs are short ; the third species differing from the
others by the absence of a mane on the neck, hack, and belly.
T. gratus agrees with this group in coloration (the mane being
■ / - ,v '"/n£~-?gpg=
.
Fig. 143. — The Kudu (Strepsiceros kudu). From Sclater, List of Animate in Zoological Society's
Gardens, 1883, p. 136.
absent), but differs in the extreme elongation of its hoofs. The
Xakong, T. spekei, while having the long hoofs of T. grains, has a
perfectly plain body coloration, with a mane on the neck. The two
species with elongated hoofs inhabit swampy districts, for which
this peculiar structure is admirably adapted ; and the Nakong, when
frightened, will rush into the water and leave only its nostrils and
the tips of the horns above the surface. The small Bushbuck
(T. sylvaticus) of South Africa has no stripes, and short hoofs.
Strepsiceros} — Females hornless. Horns (Fig. 143) more twisted
than in Tragelaphus, forming an open spiral, with the anterior ridge
1 Gray, List. Mamm. Brit. Mas. p. 155 (1843).
348 UNGULATA
very strongly developed, and rising at an obtuse angle to the plane
of the nasals. Skull with large supraorbital pits, large lachrymal
fissure, and deep intercornual depression. Hoofs short. Body with
white vertical stripes descending from a longitudinal dorsal streak.
Two existing species.
The Kudu (S. kudu, Fig. 143) extends from South Africa to
Abyssinia, and is only inferior in size to the Eland. The horns
are about 4 feet in length, and form a very open spiral, and
there is a fringe of long hair down the front of the neck. The
Lesser Kudu (S. imberbis), of Somali-land is a much smaller form,
without the fringe of hair on the neck, and with a much smaller
axis formed by the spiral of the horns.
An imperfect skull from the Pliocene of Northern India has
been referred to Strepskeros.
Oreas. 1 — Females horned. Horns twisted on their own axis,
with very strong ridges, inclining upwards and outwards in the
plane of the nasals. General characters of skull as in preceding
genus. Stripes on body, if present, very faintly marked. One
existing species.
The Eland (0. canna) is the largest of all the Antelopes, the
males standing nearly 6 feet at the withers. One variety from
South Africa is of a uniform pale fawn colour, while the Central
African form is of a bright tan colour, marked by a number of thin
pale vertical stripes descending from a dark dorsal ridge — these
markings fading more or less in the adults. The males have a
large dewlap, a tuft of brown hair on the forehead, and a small
mane on the neck. The straight black horns of the male are
usually about 18 inches long. Elands were formerly extremely
abundant in Southern and Eastern Africa, but their destruction
has been so relentless that they have totally disappeared from
extensive areas, and are daily becoming scarcer.
Portions of upper jaws from the Pliocene deposits of India appear
to indicate the former existence in that area of large Antelopes
closely allied to the Eland, but distinguished from the living species
by the greater size of the inner accessory column in the upper
molars.
Allied Extinct Types. — Large Antelopes with spirally twisted
horns appear to have been common over Southern Europe in Pliocene
times, but their exact affinity is in many cases difficult to determine.
Of these, Palceoreas, which occurs in the Lower Pliocene of Europe
and Algeria, appears to present affinities both to Oreas and
Strepsiceros, and may have been the ancestral type from which
these two genera are derived ; the upper molars have well-developed
accessory columns.
The so-called Antilope torticornis, of the French Pliocene,
1 Desmarest, Mammalogie, p. 471 (1822).
BOVID.K 349
resembles Trageta/phus in the greater development of the posterio]
;is compared with the anterior ridge of the horn-cores, and has
accordingly been referred to that genus. I'fotnigelaphus, of the
Lower Pliocene of Attica, differs from all the other types in the
absence of the anterior ridge on the horn -cores and of the
supraorbital pits, while it has a distinct lachrymal fossa.
In tin's place it will be convenient to notice certain fossil forms
which do not accord with any of the existing sections of the family,
and for the reception of which the Palceotragine section has been
formed. In these types the horn-cores are laterally compressed
like those of the modern Goats, but the upper molars resemble those
of the brachydont Antelopes. The earliest of these genera, and the
first representative of the Antelopes yet known, is Protragoceros, of
the Middle Miocene of France, first described as Antilope clavata ;
Palceotragoceros and Tragoceros, of the Lower Pliocene, are distin-
guished by their larger horns and wider molars.
A remarkable large Antelope from the Lower Pliocene of the
Isle of Samos, in the Turkish Archipelago, proposed to be described
as Criotherium, appears to be unlike any other form. The horns,
which are placed on the extreme vertex of the skull, are very
short, tightly twisted, and project in front of the forehead. The
upper molars have short and broad crowns, with no accessory
column on the inner side.
Hiipiraprine Section. — The Caprine Antelopes, as the typical
members of this section may be termed, appear to connect the true
Antelopes with the Goats. They are mostly small or medium-
sized forms, inhabiting portions of the Palsearctic and Oriental
regions, with one outlying North American genus. The typical
forms present the following features. Horns present, and of nearly
equal size in both sexes, rising behind the orbits, short, ringed at
the base, conical or somewhat compressed, and recurved. Sub-
orbital gland generally present, in some cases small. Build clumsy ;
hoofs large ; tail short, tapering, hairy above. Skull with lachrymal
fossa, but no fissure. Molars as in the Caprine section.
Rv/pimpra} — Horns short and cylindrical, rising perpendicularly
from the forehead for some distance, then bending sharply back-
wards and downwards, forming hooks with pointed tips. Premaxillse
not reaching the nasals. One species, Palsearctic.
The Gemse, or Alpine - Chamois (U. tragus), inhabits the high
mountains of Europe from the Pyrenees to the Caucasus. It stands
about 2 feet in height at the withers. The body is covered in
winter with long hair of a chestnut-brown colour, that of the head
being paler, with a dark brown streak on each side. At other
seasons the colour is somewhat lighter, in spring approaching
to gray. Underneath the external covering the body is further
1 De Blainville, Bull. Soc. Philom. 1816, p. 75.
55°
UNGULATA
protected from cold by a coat of short thick wool of a grayish colour.
The tail is black ; the ears are pointed and erect ; the hoofs have the
outer edges higher than the soles, and are thus admirably adapted
for laying hold of the slightest projection or roughness on the face
of the rocky precipices it frequents. The Chamois is gregarious,
living in herds of fifteen or twenty, and feeding generally in the
morning or evening. The old males, however, live alone, except in
the rutting season, which occurs in October, when they join the
herds, driving off the young males, and engaging in contests with
Fig. 144. — Nemorhcedus crispus. From Sclater, hist of Animals in Zoological Society* Gardens,
18S3, p. 151.
each other that often end fatally. The period of gestation is
twenty Aveeks, when the female, beneath the shelter of a projecting
rock, produces one and sometimes two young. In summer the
Chamois ascends to the limits of perpetual snow, being only out-
stripped in the loftiness of its haunts by the Ibex ; and during that
season it shows its intolerance of heat by choosing such browsing
grounds as have a northern exposure.
Nemorhcedus. 1 — Horns rounded, gradually recurving, without
distinct hook at the end. Suborbital gland small or wanting ; ears
large ; skull with a large lachrymal depression, and the premaxilla?
not quite reaching the nasals. Some nine species, ranging from
the Eastern Himalayas to North China and Japan, and southwards
1 Hamilton-Smith, in Griffith's Animal Kingdom, vol. v. p. 352 (1827).
BOVID^E 351
to Formosa, the .Malay Peninsula, and Sumatra. The smallest
spcics is the Himalayan (Jural (X. goral). Of the larger forms we
may incut inn the Himalayan Serow (.Y. bubalinus) the Cambing-
CJtan (.Y. sumatrensis) of Sumatra, and the Japanese A r . cris/ms
(Fig. 111). Of the Serow, Colonel Kinloch remarks that "it
is a large and powerful beast. The body is covered with very
coarse hair, which assumes the form of a bristly mane on the
head and shoulders, and gives the beast a ferocious appearance,
which does not belie its disposition. The colour is a dull black
on the back, bright red on the sides, and white underneath, the
legs also being dirty white. The ears are very large, the muzzle
is coarse. The Serow has an awkward gait, but in spite of this can
go over the worst ground ; and it has perhaps no superior in going
down steep hills. It is a solitary animal, and nowhere numerous."
Haploceros. 1 — The Rocky-Mountain Goat {Haploc&ros montanus),
inhabiting the northern parts of California, appears to be very
closely allied to Xemorluvdus. The horns are somewhat compressed
at the base ; there is no suborbital gland ; and the ears are small.
The hair, which is whitish in colour, is very long, and especially
abundant in the region of the throat, shoulders, flanks, and tail.
The animal is about the size of a large Sheep.
Budorcas.' 1 — The Takin (B. taxicolor) of the Mishmi Hills in
Assam, and an allied species from Eastern Tibet, are larger forms
apparently related to Xemorhiedus, but with a much greater develop-
ment of the horns. The horns of what is considered to be the
male 3 arise from the vertex of the skull, and are nearly in con-
tact in the middle line; they first bend outwards and downwards,
and then suddenly upwards and backwards. Those regarded by
Mr. Hume as referable to the female are directed at first outwards,
and then gradually curve upwards and backwards, without any down-
ward flexure or angulation. The horns of the male may be 2 feet in
length, with a basal diameter of 1 3 inches. The muzzle is hairy, with
a small naked muffle. There appear to be considerable seasonal
and sexual variations in colour ; the body being in some cases of
a yellow dun, while in others it is a dusky, reddish -brown, with
much black intermingled. The heads of large males are blackish.
Scarcely anything is known of the habits of the Takin, which
never appears to have been seen alive by Europeans.
Caprine Section. — Both sexes with horns, but those of the female
small. Horns usually compressed, triangular, with transverse
ridges, and either curving backwards or spiral. Muzzle hairy,
without naked muffle. Suborbital gland small or absent ; lachrymal
1 Hamilton -Smith, in Griffith's Animal Kingdom, vol. v. p. 354 (1827).
Amended from " Aploeerus."
2 Hodgson, Joi/rn. As. Soc. Bengal, vol. xix. p. 65 (1850).
3 See A. 0. Hume, Proc. Zool. Soc. 1887, pp. 483-486.
352
UNGULATA
fossa of skull present or absent. Tail short and flattened. Foot-
glands frequently present. Molars very hypsodont ; those of the
upper jaw being narrow, without an accessory internal column.
Mainly Palsearctic, but with some outlying forms.
This section includes the Goats and Sheep, which are so closely
connected that it is difficult to give well-marked generic characters
that will hold good for all the species. They seem to be one of
Fig. 145. — The Alpine Ibex (Capra ibex).
the latest developments of the Bovidiv, since they are unknown
before the Pliocene period ; and are essentially mountain forms.
Capra. 1 — Horns flattened from side to side, and either curving
backwards (Fig. 145) or spirally twisted. No suborbital gland,
and no lachrymal fossa in the skull. Foot-glands, if present, only
in the fore feet. Chin more or less bearded. Males Avith a strong
odour. Vertebra?: C 7, D 13, L 6, S 4, C 9-13. Some dozen species,
ranging over all the higher mountains of Southern Europe, from
Spain to the Caucasus ; also found in Abyssinia, Persia, Sind, and
Baluchistan, thence through the higher Himalaya, and so on to
Tibet and Northern China. One outlying species occurs in the
Nilgherries of Southern India.
1 Linn. Syst, Nat. 12th ed. vol. i. p. 94 (1766).
BOVID.E 353
The European Ibex or Steinbok (Fig. 145), which may bo
taken as a typical Groat, stands about 2£ feet in height at the
shoulder. In summer the hair is short and smooth, and of an
ashy-gray colour, but a long coat is developed in winter. The
horns of the male rise in a bold backward sweep from the forehead,
and are characterised by the strong transverse ridges on the broad
and Hat anterior surface. They are said to be not more than some
•_' feet in length, but these dimensions are greatly exceeded by the
horns of the Himalayan Ibex. The Alpine Ibex lives at a greater
height than the Chamois, spending the day just at the limit of
perpetual snow, and descending at night to graze at lower levels.
Both this and the Himalayan species generally live in small herds
of from five to fifteen or more ; they are wary animals, although not
so much so as many of the wild Sheep. The following list, mainly
taken from two papers by Mr. Sclater, 1 gives the distribution
of the various species of Goats, with some remarks on their
peculiarities : —
(1) C. ibex, confined to the Alps of Switzerland, Savoy, and
the Tyrol, and now nearly extinct, except where artificially pre-
served. (2) ft sibirica, closely allied to the preceding, but with
larger horns, occurs in the Altai Mountains, and throughout the
Himalaya from Kashmir to Nipal, and northward towards Turke-
stan. (3) ft sinaitica, of the mountains of Upper Egypt, the
Sinaitic Peninsula, and Palestine, is allied to the two preceding
species, but has the horns somewhat more compressed, with a
difference in the ridges on the front. (4) C. caucasica, a very
distinct species, confined to the Caucasus, where it inhabits the
western part of the Great Caucasus; with thick horns curving
backwards and outwards in one plane, with the exception of their
tips, which incline inwards. 2 (5) ft pallasi is an allied species from
the Eastern Caucasus, distinguished, among other features, by the
curvature of the horns, which lie flatter and twist more outward
from the forehead, with a greater terminal inward bend. (6) ft
pyrenaica, of the Pyrenees, and the higher ranges of Central Spain,
Andalusia, and Portugal, is another nearly related species. (7)
ft cegagrus, formerly abundant over the Grecian Archipelago, but
now restricted in Europe to Crete and some of the Cyclades, is
found throughout the mountains of Asia Minor and Persia, and
thence to Baluchistan and Sind. The horns are thinner and
sharper in front than in the Ibexes, and this species is generally
regarded as the ancestral stock of the various breeds of domestic
Goats. (8) C. clorcas, a Goat from the island of Jura, near Euboea,
has been described under this name, and is apparently nearly allied
1 Proc. Zool. Soc. 1886, p. 314 ; and 1887, p. 552.
2 Specimens referred by Dinnik to C. caucasica have been made the types of
another species — C. severLwi.
23
554 UNGULATA
to C. cegagrus. (9) C. walie, an apparently well - characterised
species from the highest ranges of Abyssinia. (10) C. falconer i ;
the Markhoor differs from all the preceding species by the spiral
twisting of its horns, which attain enormous dimensions. It occurs
in the Pir - Panjal range south of Kashmir, and thence into
Afghanistan and the Suleiman range, and northwards to Astor,
Gilgit, and Scardo (Baltistan). The specimens from the Suleiman
range have the spiral of the horns very close, somewhat as in the
Eland ; while in those from Astor, Gilgit, and Scardo it is very open,
as in the Kudu. The Pir-Panjal race occupies a somewhat inter-
mediate position in this respect. (11) C. jemlaica, the Thar,
inhabits suitable regions along the whole range of the Himalaya
from Kashmir to Bhutan. Together with the next species, it
differs from the more typical Goats in its short, thick, and much
compressed horns, the anterior border of which is keeled, and the
moist naked muffle. There are no glands in the fore feet. It was
generically separated by Gray as Hemitragus. (12) C. hylocrms,
the so-called Ibex of the Nilgherries, Anamallays, and other adjoin-
ing ranges of Southern India, is an outlying species, apparently
allied to the preceding, but with somewhat different horns, in
which the external angle in front is much rounded off.
Of fossil Goats Ave have but little knowledge. Eemains of
C. pyrenaka are found in cave-deposits at Gibraltar ; and it is not
improbable that the genus is represented in the Upper Pliocene of
France. Several species occur in the Pliocene of India, C. siralensis
being apparently closely allied to C. jemlaica, while another has
horns resembling those of C. falconeri, and it is possible that a
third may be more nearly related to the Ibexes.
Ovis. 1 — Horns curving backwards and downwards in a bold
sweep, with the tips everted, generally with more or less prominent
transverse ridges, and brownish in colour. Suborbital gland and
lachrymal fossa usually present, but generally small. Foot-glands
in all the feet. Chin not bearded ; 2 males without a strong odour.
Vertebrae: C 7, D 13, L 6, S 4, C 10-14. Some twelve species,
mainly Palsearctic, but extending into the adjacent portions of the
Oriental region, and with one outlying species in North America.
The more typical Sheep are closely connected with the Goats by
the Himalayan Bharal (0. nahura) and the Aoudad (0. tragelaphus) of
Northern Africa, both these species having no suborbital gland and
no lachrymal fossa, while their comparatively smooth and olive-
coloured horns show a decided approximation to those of the
Goats. Both present, however, the ovine character of glands in
all the feet. In the typical Sheep the basioccipital of the skull
is wider in front than behind, with the anterior pair of tubercles
1 Linn. Syst. Nat, 12th ed. vol. i. p. 97 (1766).
2 There may be a beard on the throat, as in 0. cycloccros.
B0V1DJ-: 355
widely separated and much larger than the posterior pair. The
r.haral, however, resembles the Goats in having an oblong basi-
occipital, with the posterior tubercles larger and more prominent
than the anterior ones, both being situated in the same antero-
inferior line. These transitions towards the caprine type are,
however, not sufficient to support the view that the Bharal should
form the type of a distinct genus (Pseudois), more especially since
some of the typical Sheep, like 0. canadensis, have the lachrymal
fossa of the skull very much reduced in size.
The distinction of the various permanent modifications under
which wild Sheep occur is a matter of considerable difficulty. Trivial
characters, such as size, slight variations in colour, and especially
the form and curvature of the horns, are relied upon by different
zoologists who have given attention to the subject in the discrimina-
tion of species, but no complete accord has yet been established.
The most generally recognised forms are enumerated below.
The geographical distribution of mid Sheep is interesting. The
immense mountain ranges of Central Asia, the Pamir and Thian-
Shan of Turkestan, may be looked upon as the centre of their
habitat. Here, at an elevation of 16,000 feet above the sea-level,
is the home of the magnificent Ovis poll, named after the celebrated
Venetian traveller Marco Polo, who met with it in his adventurous
travels through this region in the thirteenth century. It is remark-
able for the great size of the horns of the old rams and the wide
open sweep of their curve, so that the points stand boldly out on each
side, far away from the animal's head, instead of curling round
nearly in the same plane, as in most of the other species. A Sheep
from the same region, in which the .horns retain their more normal
development, has received the name of 0. Jcarelini, but, according to
Mr. W. T. Blanford, 1 is not distinct specifically from 0. poll East-
ward and northward is found the Argali (0. argali), with a wide and
not very well determined range ; it formerly occurred in the Altai,
but is now found in Northern Mongolia. Still farther north, in the
Stanovoi Mountains and Kamschatka, is 0. nivicola, and away on
the other side of Behring's Strait, in the Eocky Mountains and
adjacent highlands of Avestern North America, is the "Bighorn"
or Mountain Sheep (0. canadensis), the only member of the genus
found in that continent, and indeed — except the Bison, Musk-Ox,
Mountain Goat {Haploceros), and the Prong-buck (Antilocapra) —
the only hollow -horned Euminant, being like the rest obviously
a straggler from the cradle of its race. The two last-named
species are nearly allied, and are characterised by the slight
development of the ridges on their horns and the very shallow
lachrymal fossa. Turning southward from the point from which we
started, and still a little to the east, in Nipal and Western Tibet,
1 Proc. Zool. Soc. 1SS4, p. 326.
356
UNGULATA
is the Himalayan Argali (0. hodgsoni), having massive and strongly
curved horns, with bold ridges, like those of the true Argali.
Indeed, were it not for their isolated areas there would appear to
be no grounds for distinguishing these two closely allied forms,
and it is not improbable that they are really identical. 0. brookei
appears to have been founded on a hybrid between 0. hodgsoni and
0. vignei. In the same districts, and also in Southern Ladak, there
occurs the Bharal (0. itahura), with smaller, smoother, and more
spreading horns. Passing in a south-westerly direction we find a
series of smaller forms, 0. vignei of Ladak, 0. cycloceros of Northern
Fig. 146.— The Moufflon (fivis musiinon). From a living animal in the London Zoological
Gardens.
India, Persia, and Baluchistan, 0. gmelini of Asia Minor and Persia,
0. ophion, confined to the. elevated pine-clad Troodos Mountains of
the island of Cyprus, and said at the time of the British occupa-
tion in 1878 to have been reduced to a flock of about twenty-five
individuals, and 0. musimon, the Moufflon of Corsica and Sardinia
(see Fig. 146), believed to have been formerly also a native of
Spain. In the three latter species the females are hornless. Lastlv,
we have the somewhat aberrant, Goat-like Aoudad (0. tragelaphus),
of the great mountain ranges of North Africa, in which, as already
mentioned, the skull and horns resemble those of the Bharal,
although the tail is longer, and there is a thick fringe of long hair
on the throat, chest, and fore legs.
BOVIDjE 357
We thus find that Slurp are essentially inhabitants of high
mountainous parts of the world, for dwelling among which their
wonderful powers of climbing and leaping give them special
advantages. No species frequent by choice either level deserts,
open plains, dense forests, or swamps. By far the greater number
of species are inhabitants of the continent of Asia, one extending
into North America, one into Southern Europe, and one into North
Africa. No wild Sheep exist in any other part of the world,
unless the so-called Musk-Ox of the Arctic regions, the nearest
existing ally to the true Sheep, may be considered as one. Geo-
logically speaking, Sheep appear to be very modern animals, or
perhaps it would be safer to say that no remains that can be with
certainty referred to the genus have been met with in the hitherto
explored true Tertiary beds, which have yielded such abundant
modifications of Antelopes and Deer. They are generally con-
sidered not to be indigenous in the British Isles, but to have been
introduced by man from the East in prehistoric times. A fossil
Sheep (Ovis savigni), apparently allied to the Argali, has, however,
been described from the so-called Forest-bed of the Norfolk coast.
The Sheep was a domestic animal in Asia and Europe before
the dawn of history, though cpiite unknown as such in the New
World until after the Spanish conquest. It has now been intro-
duced by man into almost all parts of the world where settled agri-
cultural operations are carried on, but flourishes especially in the
temperate regions of both hemispheres. Whether our well-known
and useful animal is derived from any one of the existing wild
species, or from the crossing of several, or from some now extinct
species, is quite a matter of conjecture. The variations of external
characters seen in the different domestic breeds are very great.
They are chiefly manifested in the form and number of the horns,
which may be increased from the normal two to four or even eight,
or may be altogether absent in the female alone, or in both sexes ;
in the form and length of the ears, which often hang pendent by
the side of the head ; in the peculiar elevation or arching of the
nasal bones in some Eastern races ; in the length of the tail, and
the development of great masses of fat at each side of its root, or
in the tail itself ; and in the colour and quality of the fleece.
Ovibos. 1 — This genus is generally considered to be a connecting
link between the Caprine and Bovine sections, but should rather
be regarded as an aberrant type of the former. Horns of adult
male rounded, smooth, and closely approximated at their bases,
where they are depressed and rugose ; curving downwards, and
then upwards and forwards. Muzzle caprine ; no suborbital gland,
no lachrymal fossa or fissure in skull ; orbits tubular ; a large narial
aperture and very short nasals ; premaxillse not reaching nasals.
1 De Blainville, Bull. Soe. Philom. 1816, p. 76.
353
UNGULATA
Tail short, and molar teeth caprine. One existing and two fossil
species, Palaearctic and Nearctic.
The animal commonly known as the Musk-Ox (Ovibos moscliatus),
though approaching in size the smaller varieties of Oxen, is in
structure and habits closely allied to the Sheep, its affinities being
well expressed by the generic name Ovibos bestowed upon it by
De Blainville. The specific name, as also the common English
appellatives " Musk-Ox," " Musk-Buffalo," or " Musk-Sheep," applied
to it by various authors, refer to the musky odour which the animal
exhales. This does not appear to be due to the secretion of a
special gland, as in the case of the Musk-Deer; but it must be
; Fig. 147.— The Musk-Ox (Ovibos moschatus).
observed that, except as regards the osteology, very little is known
of the anatomy of this species. It about equals in size the small
Welsh and Scotch cattle. The head is large and broad. The horns
in the old males have extremely broad bases, meeting in the median
line, and covering the brow and whole crown of the head. They
are directed at first downwards by the side of the face and then
turn upwards and forwards, ending in the same plane as the eye.
Their basal halves are of a dull white colour, oval in section and
coarsely fibrous; their middle part smooth, shining, and round ; then-
tips black. In the females and young males the horns are smaller,
and their bases are separated from each other by a space in the
middle of the forehead. The ears are small, erect, and pointed, and
nearly concealed in the hair. The space betAveen the nostrils and
the upper lip is covered with short close hair, as in Sheep and Goats,
without any trace of the bare muffle of the Oxen. The greater part
BOVIDjE 359
of the animal is covered with long brown hair, thick, matted, and
curly on the shoulders, so as to give the appearance of a hump, but
elsewhere straight and hanging down, — that of the sides, back, and
haunches reaching as far as the middle of the legs and entirely
concealing the very short tail. There is also a thick woolly under-
fur, shed in the summer. The hair on the lower jaw, throat, and
chest is long and straight, and hangs down like a beard or dewlap,
though there is no loose fold of skin in this situation as in Oxen.
The limbs are stout and short, terminating in unsymmetrical hoofs,
the external one being rounded, the internal pointed, and the sole
partially covered with hair.
The Musk-Ox is at the present day confined to the most northern
parts of North America, where it ranges over the rocky barren
grounds between the 60th parallel and the shores of the Arctic
Sea. Its southern range is gradually contracting, and it appears
that it is no longer met with west of the Mackenzie River, though
formerly abundant as far as Eschscholtz Bay. Northwards and
eastwards it extends through the Parry Islands and Grinned Land
to North Greenland, reaching on the west coast as far south as
Melville Bay ; and it was also met with in abundance by the
German polar expedition of 1869-70 at Sabine Island on the east
coast. No trace of it has been found in Spitzbergen or Franz
Joseph Land. As proved by the discovery of fossil remains, it
ranged during the Pleistocene period over northern Siberia and the
plains of Germany and France, its bones occurring very generally
in river deposits along with those of the Reindeer, Mammoth, and
Woolly Rhinoceros. It has also been found in Pleistocene gravels
in several parts of England, as Maidenhead, Bromley, Freshfield
near Bath, Barnwood near Gloucester, and also in the lower brick-
earth of the Thames valley at Crayford, Kent.
It is gregarious in habit, assembling in herds of twenty or thirty
head, or, according to Hearne, sometimes eighty or a hundred, in
which there are seldom more than two or three full-grown males.
The Musk-Ox runs with considerable speed, notwithstanding the
shortness of its legs. Major H. W. Feilden, naturalist to the Arctic
expedition of 1875, says: "No person watching this animal in a
state of nature could fail to see how essentially ovine are its actions.
When alarmed they gather together like a flock of sheep herded by
a collie dog, and the way in which they pack closely together and
follow blindly the vacillating leadership of the old ram is unquestion-
ably sheep-like. When thoroughly frightened they take to the hills,
ascending precipitous slopes and scaling rocks with great agility."
They feed chiefly on grass, but also on moss, lichens, and tender
shoots of the willow and pine. The female brings forth a single
young one in the end of May or beginning of June after a gestation
of nine months. According to Sir J. Richardson, " when this animal
360 UNGULATA
is fat its flesh is well tasted, and resembles that of the Caribou, but
has a coarser grain. The flesh of the bulls is highly flavoured, and
both bulls and cows when lean smell strongly of musk, their flesh
at the same time being very dark and tough, and certainly far
inferior to that of any other ruminating animal existing in North
America." The carcase of a Musk-Ox weighs, exclusive of fat, above
3 cwt. On this subject, Major Feilden J says : " The cause of the
disagreeable odour which frequently taints the flesh of these animals
has received no elucidation from my observations. It does not
appear to be confined to either sex, or to any particular season of
the year ; for a young unweaned animal, killed at its mother's side
and transferred within an hour to the stew-pans, was as rank and
objectionable as any. The flesh of some of these animals of which
I have partaken was dark, tender, and as well flavoured as that of
four-year old Southdown mutton."
Remains of two fossil species of this genus (0. bombifrons and
0. cavifrons) have been described from Pleistocene beds in the
United States, the one from Kentucky and the other from the
Arkansas River. Both (if indeed they be valid species) appear
closely allied to the living form.
Bovine Section. — Horns present and of nearly equal size in both
sexes ; in form rounded or angulated, placed on or near the vertex
of the skull, extending more or less outwards, and curving upwards
near the extremities ; external surface comparatively smooth and
never marked by prominent transverse ridges or knobs. Muzzle
broad, with large naked muffle ; nostrils lateral ; no suborbital
gland. Skull without any trace of lachrymal fossa or fissure. Tail
long and cylindrical ; generally tufted at the extremity, rarely
hairy throughout. Males usually with a dew-lap on the throat. No
foot-glands. Molar teeth extremely hypsodont ; those of the upper
jaw with a nearly square cross-section, and a large accessory inner
column.
The section is abundantly represented in the Palsearctic,
Oriental, and Ethiopian regions, Avith one Nearctic species and an
outlying and aberrant species in Celebes.
Bos. 2 — The whole of the species of Oxen were included by
Linnaeus in the single genus Bos, and although the species have
been distributed by modern zoologists in several genera — such as
Anoa, Bubalus, Bison, Po'ephagus, Bibos, and Bos — the characters by
which they are separated are so slight that it seems, on the whole,
preferable to retain the old genus in its original wide sense. Using
then the term Bos in this sense, it will include all the representatives
of the section — about a dozen in number — and may be divided
into several groups.
1 Zoologist, September 1877.
2 Linn. Syst. Nat. 12th. ed. vol. i. p. 98 (1766).
BO VI IKE 361
The first group includes the Buffaloes (genus Bvibalus), chiefly
characterised by their more or less flattened and angulated horns,
which incline upwards and backwards, with an inward curve
towards their tips, and are placed below the plane of the occiput,
or vertex of the skull. The premaxillaj reach to the nasals, and
the vomer is peculiar in being so much ossified as to join the
posterior border of the palate. The back has a distinct ridge in
the region of the withers ; and the forehead is frequently convex.
Oriental and Ethiopian region, and Celebes.
The most generalised representative of this group is the small
Anoa (/>'. d&pressiwrnis) of Celebes, the type of the genus Anoa or
Probubalus, which has the same cranial structure as in the more
typical Buffaloes, to the young of which (as was pointed out by
the late Professor Garrod) it presents a striking resemblance. Its
colour is black ; and the short and prismatic horns are directed
upwards from the forehead. In the Pliocene Siwaliks of India
there occur the remains of larger Buffaloes (B. occipitalis and
B. acuticornis) closely allied to the Anoa, but with longer and more
distinctly angulated horns. The still larger B. platyceros of the
last-named deposits, in which the horns are wide -spreading and
much flattened, appears to be in some respects intermediate between
the preceding and following forms. The typical Indian Buffalo
(Bos buffdus), which has been domesticated over South-East Asia,
Egypt, and Southern Europe, is, in the wild state, a gigantic animal
with enormous horns. These horns are longer, more slender, and
more outwardly directed in the female than in the male; and in
the former sex may have a length of more than 6 feet from base
to tip. They are widely separated at their bases, the forehead is
very convex, and the ears are not excessively large, and have no
distinct fringe. These Buffaloes frequent swampy and moist dis-
tricts in several parts of India, but it is in many instances difficult
to decide whether they belong to really wild or to feral races.
Very large skulls, specifically indistinguishable from those of the
existing form, occur in the Pleistocene deposits of the Xarbada
valley in India ; while an allied, if not specifically identical form,
occurs in the Pliocene of the same country. There is some doubt
whether B. antiquus of the Pleistocene of Algeria is most nearly
related to the Indian or to the African species.
In Africa two species of Buffalo are recognised by Sir Victor
Brooke, 1 namely the large B. caffer, occurring typically at the Cape,
but said by this writer to range to Abyssinia, and the smaller
B. pumilus, which seems to have a very wide distribution. The
skulls of both these forms are shorter than in the Indian species,
while the horns are also shorter, much more curved inwardly, and
more approximated on the forehead. In the large typical form of
1 Proc. Zool. Sue. 1873, p. 474.
362 UNGULATA
B. caffer from South Africa the colour is black, the horns of the male
are very thick, much reflected, and closely approximated on the
forehead, where they form a helmet-like mass. 1 The large northern
form described as B. cequinoctialis has the horns somewhat less thick,
and thus approximates to the so-called B. pumilus.
The latter occurs typically in Western Africa, where it has also
been described as B. brachyceros. In the typical form the horns are
thinner and less reflected than in B. caffer, and in some specimens
they are more widely separated on the forehead, and are marked at
their bases by distinct rugse. The colour is ruddy brown, inclining
to rufous in one specimen. The skulls of Buffaloes from West
Africa, probably referable to the form described as B. centralis, appear
to connect B. pumilus with B. caffer, as shown by their larger size
and the form of their horns ; so that further observations are
required to show whether the smaller form is really entitled to
rank as a distinct species, or merely as a well-marked local race.
The second group comprises the Bisons, which are more nearly
allied to the true Oxen, having similar rounded horns, but the skull
being less massive, with a longer and more tapering frontal region,
and a wider frontal diameter. The superior part of the forehead
is transversely arched, the intercornual space elevated in the
middle, the horns situated below the plane of the occiput, and
the orbits more or less prominent. The premaxillee do not extend
upwards to reach the nasals. The Bisons (Fig. 148) have the body
covered with short, crisp, woolly hair, Avhile on the head and neck
there is an abundance of much longer and darker hair, which forms
a mane concealing the eyes, ears, and the bases of the horns. There
is also a long beard beneath the chin ; while a line of long hair
extends from the head nearly to the tail, the latter being tufted
at the extremity. The withers are much higher than the hind
quarters, so that there is a kind of hump at the shoulders.
The groiqD is represented by two species — the European and
the American Bison. The former is the Bos bonasus of Linnaeus,
and is also identical Avith the Bos bison of Ray. The German name
Wisent is the equivalent of the Greek Bison. The American
species is the Bos americanus of Gmelin. Both species are closely
allied, but the American Bison is slightly the smaller animal of
the two, and is shorter and weaker in the hind quarters, with
a smaller pelvis ; its body is, however, more massive in front ;
and the hair on the head, neck, and fore quarters is longer and
more luxuriant. A large bull American Bison, preserved in the
Museum at Washington, stands 5 feet 8 inches in height at the
withers. The European Bison appears to have been formerly
1 Sir V. Brooke states that this species is distinguished from B. pumilus by
the absence of a fringe to the ears, but specimens in the British Museum show
that this is not the case.
BOVlLhE
363
abundant over a large portion of Europe in the Pleistocene period
— the fossil r.uc described as B. priseus not being specifically dis-
tinct ; but at the present day it exists only in the primeval forests
of Lithuania, Moldavia, Wallachia, and the Caucasus, where it is
artificially preserved.
The American Bison formerly ranged over about one-third of
the North American continent. Thus, to quote from Mr. Horna-
day, 1 " starting almost at tide-water on the Atlantic coast, it ex-
tended across the Alleghany mountain system to the prairies along
the Mississippi, and southward to the delta of that great system.
Fig. 14S. — The American Bison (Bos americanus). After Hornaday.
Although the great plain country of the West was the natural
home of the species, where it flourished most abundantly, it also
wandered south across Texas to the burning plains of North-Eastern
Mexico, westward across the Rocky Mountains into New Mexico,
Utah, and Idaho, and northward across a vast treeless waste to the
bleak and inhospitable shores of the Great Slave Lake itself." In
consequence of the settlement of the country by Europeans the area
inhabited by the Bison was gradually contracted, till about 1840
one mighty herd occupied the centre of its former range. The
completion of the Union Pacific Eailway in 1869 divided this great
herd into a southern and a northern division, the former comprising
a number of individuals estimated at nearly four millions, while the
latter contained about a million and a half. Before 1880 the
southern herd had, however, practically ceased to exist ; while the
same fate overtook the northern one in 1883. In 1889 some twenty
stragglers in Texas represented the last of the southern herd ;
while there were a few others in Colorado, Wyoming, Montana,
1 The Extirpation of the American Bison, 1889.
364
UNGULATA
and Dakota. A herd of some two hundred wild individuals,
derived from the northern herd, is preserved by the United States
Government in the Yellowstone National Park ; and it is believed
that some five hundred of the race known as AVood-Bison exist in
British territory ; but with these exceptions this magnificent species
is exterminated. The multitudes in which the American Bison
formerly existed are almost incredible ; the prairies being absolutely
black with them as far as the eye could reach, and the numbers
in the herds being, as we have said, reckoned by millions. Mr.
Hornaday even considers that the whole of the game in South
Fig. 149. — The Yak (Bos grunniens), domestic variety.
Africa was never equal to the number of Bison on an equal area of
the American prairies.
An extinct Bison from the Pleistocene of Texas, known as Bos
latifrons, was probably the ancestor of the recent American species.
The Yak (Bos grunniens) appears to be allied both to the Bisons
and the true Oxen, being distinguished from the former by the
different position occupied by the long hair, which forms a fringe
investing the shoulders, flanks, and thighs, and grows over the
whole of the tail. In the skull the orbits are less tubular, the fore-
head flatter, and the premaxillae less widely separated from the
nasals. There is no distinct dewlap. Wild Yaks inhabit the
higher regions of Chinese Tibet and the region of the Karakoram,
as well as the more outlying parts of Ladak, such as the Chang-
chemo valley. Owing, however, to incessant pursuit those now found
within the territories of the Maharaja of Kashmir are stragglers
BOVIDjE 365
from Chinese Tibet. The height of the Yak is somewhat lower
than that of the larger domestic cattle. The colour of the wild race
is black, tending to brown on the tlanks; but many of the tame
breeds which have been crossed with ordinary cattle have more or
less white (Fig. 149), and it is the white tails of these half-breeds
that are so esteemed in India as "chowries." Yaks are exceedingly
intolerant of heat, and the wild ones always live at very great
elevations. Tame Yaks are extensively used as beasts of burden
in Tibet, where they are extremely valuable in crossing the high
and desolate wastes of that region; they have, however, the great
drawback that they refuse to eat corn, so that in districts where
there is no grass it is frequently necessary to make forced marches
with Avearied beasts in order to prevent them (and thus the whole
party) perishing from starvation.
The skull of an extinct species from the Pliocene of Northern
India, described as Bos sivaknsis, appears to indicate a species allied
to the Yak.
With the Bibovine group we come to the consideration of three
Oriental species which connect the preceding forms with the
typical Oxen. The three species are the Gaur (B. gaurus) the
Gayal (B. frontalis, Fig. 150) of India, and the Banteng (B. sondaicus)
of Burma, Java, Bali, and Lambok. In this group, as in the true
Oxen, there are thirteen pairs of ribs, against fourteen in the
Bisons. All the three species are characterised by the great height
of the spines of the anterior dorsal vertebrae, causing a promi-
nent ridge down the back. The horns, which are of a greenish
colour in the Gaur, are somewhat flattened, and after running out-
wards are directed upwards instead of backwards ; they occupy the
vertex of the skull. The frontals are more or less concave, the
premaxillas do not join the nasals, and the occipital aspect of the
skull is characterised by the deep incisions made by the temporal
fossae. The lower part of the legs is white (Fig. 150), and the hoofs
are comparatively small and pointed. The Gaur (B. gaurus) is the
largest of the three species, and inhabits all the large forests of India
from near Cape Comorin to the foot of the Himalaya; it is commonly
known to sportsmen as the Indian Bison. It stands fully 6 feet in
height at the withers, which are much elevated ; and since the whole
back is arched the line from the nose to the root of the tail forms
an almost continuous curve. The most characteristic feature of the
animal is, hoAvever, the large and convex intercornual frontal crest,
Avhich curves forward, and thus gives a concave profile to this part
of the skull. As a rule the Gaur prefers hilly regions, although it
is sometimes met AAnth on the flat. It is very shy and readily
frightened ; and it has never been domesticated. The Gayal, or
Mithan, of Avhich a figure is given in Avoodcut 150, is at once dis-
tinguished from the Gaur by the straight line betAveen the horns
366
UNGULATA
(which are black in colour), owing to the absence of the intercor-
nual crest of the latter. The horns are also shorter, more rounded,
and less curved. In the Indian Museum, Calcutta, there are, how-
ever, skulls which are to a great extent intermediate between those
of typical Gaurs and those of typical Gayals, but these may belong
to hybrids. The Gayal occurs in Assam, Chittagong, and adjacent
districts, but it appears that these animals exist in a semi-domestic-
ated condition, no wild race being known to Europeans, although
it is probable that such may exist in the unexplored Mishmi Hills.
Fig. 150. — The Gayal (Bos frontalis). From Sclater, List of Animals in Zoological
Society's Gardens, 18S3.
The Banteng (B. sondaicus) is a smaller and lighter built animal
than either of the preceding, with a longer and sharper head, and
more rounded and slender horns. The dorsal ridge is, moreover,
but slightly developed ; while the bright dun colour of the body
of the female readily distinguishes it from the darker hue of the
Gaur and Gayal.
A fossil skull from the Pleistocene deposits of the Narbada
valley, India, described as Bos pakeogaurus, is believed to indicate
a species nearly allied to the Gaur, if indeed it be specifically
distinct.
BOVID.K 367
The true Oxen, or Taurine group, are now represented solely
by Bos iiiitrus ami /las indicus. Both of these species are now known
only by domesticated races, unless the herds of the former preserved
at Chillingham and some other British parks are the survivors
of an original wild race. The dorsal ridge of the Bibovine group
is here wanting ; the horns are rounded, with their extremities
directed backwards, and are placed at the extreme vertex of the
skull ; while the long frontal region is nearly flat ; the temporal
fossae scarcely intrude upon the occipital aspect of the skull ; and
the premaxillse reach the nasals. The hoofs are large and rounded.
It is known that wild Oxen were abundant in the forests of Europe
at the time of Julius Ccesar, by whom they were described as the
Urus, equal to the German Aurochs; and the large skulls found in
turbary and Pleistocene deposits, and described under the name of
Bos primigenius, can only be regarded as having belonged to the
large original race of B. taunts, of which it has been thought the
Chillingham cattle are smaller descendants. 1 The subfossil skulls
described as B. longifrons and B. frontosus must also be looked upon
as referable to smaller races of the same species. That the domestic
cattle of Europe are descendants from the various races of the same
original species there can be no doubt, but in the case of the humped
cattle of India (B. indicus) it is cprite probable that their origin
may be, at least in part, different. The extinct Bos namadicus, of
the Pleistocene deposits of India, was a species with the general
characters of the Taurine group, but with an inclination to a
flattening of the horns, and with an approximation to a Bibovine
type of occiput, as well as with the separation of the premaxillas
from the nasals.
The earliest representatives of this group occur in the Pliocene
of the Siwalik Hills in Northern India. One of these species
(]!. planifrons) appears to be allied to B. namadicus ; but the other
{B. acutifrons) was a gigantic species characterised by the sharp
median angulation of the frontal region, and the pyriform section
of the enormous horn-cores.
The extinct B. elahis, from the Upper Pliocene of France and
Italy, is the representative of a generalised type, which may be
known as the Leptobovine group. The males had rounded horn-
cores widely separated at their bases, and placed low down on the
forehead. The females (which have been described as Leptobos) were
often or always hornless. The limbs were unusually slender.
This group also occurs in the Pliocene of the Snvalik Hills.
1 The late Mr. Alston, Fauna of Scotland, " Mammalia " (Glasgow, 1S80), p. 25,
considers that the Chillingham cattle are descendants of a race which had escaped
from domestication.
368
UNGULA TA
Suborder Perissodactyla
This is a perfectly well-defined group of Ungulate mammals,
represented in the actual fauna of the world by only three distinct
types or families — the Tapirs, the Rhinoceroses, and the Horses —
poor in genera and species, and (except in the case of the two
domesticated species of Equus, which have been largely multiplied
and diffused by man's agency) not generally numerous in individuals,
though widely scattered over the earth's surface.
A B
Palaeontological
C
Fig. 151.— Bones of right fore foot of existing Perissodactyles. A, Tapir (Tapvrus indicus),
Xi; B, Rhinoceros (Rhinoceros sumatrensis), x|; C, Horse (Eqiius caballus), x§. U, ulna;
/;, radius ; c, cuneiform ; I, lunar; s, scaphoid ; w, unciform ; m, magnum ; td, trapezoid ; tm
trapezium. — From Flower, Osteology of Mammalia.
records, however, show very clearly that these are but the surviving
remnants of a very extensive and much -varied assemblage of
animals, which flourished upon the earth through the Tertiary
geological period, and which, if it could be reconstructed in its
entirety, would not only show members filling up structurally the
intervals between the existing apparently isolated forms, but would
also show several marked lines of specialisation which have become
extinct without leaving any direct successors.
The following are the principal characters distinguishing them
from the Artiodactyla. Premolar and molar teeth in continuous
series, with massive, quadrate, transversely ridged or complex
crowns, — the posterior premolars often resembling the true molars
r/'.RJSSODACTYLA 369
in size and structure. Crown of the last lower molar commonly
bilobed, and if a third lobe is present in this tooth it is wanting in
the last lower milk-molar. Dorso-lumbar vertebras never fewer than
twenty-two, usually twenty-three in the existing species. Nasal
bones expanded posteriorly. An aUsphenoid canal. Femur with
a third trochanter. 1 The middle or third digit on both fore and
hind feet larger than any of the others, and symmetrical in itself,
the free border of the ungual phalanx being evenly rounded (see
Fig. 1 5 1 ). This may be the only functional toe, or the second and
fourth may be subequally developed on each side of it. In the
Tapirs and many extinct forms, the fifth toe also remains on the
fore limb, but its presence does not interfere with the symmetrical
arrangement of the remainder of the foot around the median line
of the third or middle digit. Traces of a hallux have only been
found in some extremely ancient and primitive forms. The
astragalus has a pulleydike surface above for articulation with the
tibia, but its distal surface is flattened and unites to a much greater
extent with the navicular than with the cuboid, w T hich bone is
of comparatively less importance than in the Artiodactyla. The
calcaneum does not articulate with the lower or distal extremity of
the fibula. The stomach is always simple, the caecum is large and
capacious, the placenta diffused, and the mammae are inguinal.
The gall-bladder is invariably absent.
As regards the dentition, the whole of the premolar series
may be preceded by milk-teeth ; and it has been demonstrated in
Rhinoceros that Avhen there is no displacement of the first cheek-
tooth that tooth is a persistent milk-molar ; the same condition
apparently holding good in Palceotherium. This feature indicates
considerable dental specialisation, the milk-molars, according to the
theory generally accepted by the leading English zoologists, being
the acquired, and the premolars the original series. Another
peculiar feature of the dentition of the Perissodactyla, very rarely
met with among the Artiodactyla, is that the premolars tend to
resemble the true molars ; this feature occurring in all the existing
genera, although not found in the earlier generalised types. The
cheek-teeth of all the members of the suborder are primarily con-
structed on some modification of what is known as the lophodont
plan. Thus the upper molars (Fig. 155, p. 375) have an outer antero-
posterior wall from which proceed two transverse ridges, formed by
the coalescence of the primitive inner and outer columns, towards
the inner aspect of the crown ; while in the lower molars there
may be either two simple transverse ridges, or these ridges may be
curved into crescents, coming into contact with one another at their
extremities. Those forms having brachydont teeth show this plan
of structure in its simplest modification ; but in cases, as in the
1 Wanting in the ulicrrant < 'I/n/ir,,fh< ri",n.
24
37o UNGULATA
Horse, where the teeth assume an extremely hypsodont form, the
original plan is so obscured by infoldings of the enamel that it can
only be traced with difficulty.
At the present day the Perissodactyla are sharply differ-
entiated into Horses, Tapirs, and Rhinoceroses, but the knowledge
already gained of the extinct representatives of the suborder shows
such a close alliance between these groups that it is exceedingly
difficult to make any satisfactory classification of the whole. This
is of course exactly what might have been expected ; and the same
would doubtless be the case with all other groups if we knew as
much of their past history as we do of that of the Perissodactyles.
The detailed account of the anatomy of the Horse given in the
sequel will afford much information as to the general structure of
the members of the suborder.
Family Tapirid.e.
Both upper and lower cheek-teeth brachydont and simply
bilophodont ; hinder premolars as complex as the molars ; last lower
molar without third lobe ; first upper cheek-tooth with a milk-
predecessor. 1 Outer columns of upper molars conical. Four digits
in the manus, and three in the pes.
Tojnrus. 2 — Dentition i | c i p £, m § ; total 42. Of the
upper incisors, the first and second are nearly equal, with short,
broad crowns ; the third is large and conical, considerably larger
than the canine, which is separated from it by an interval. Lower
incisors diminishing in size from the first to the third ; the canine,
which is in contact with the third incisor, large and conical, working
against (and behind) the canine-like third upper incisor. In both
jaws there is a diastema between the canines and the commence-
ment of the teeth of the cheek -series, which are all in contact.
First upper premolar with a triangular crown, narrow in front
owing to the absence of the anterior inner cusp. The other upper
premolars and molars all formed on the same plan and of nearly
the same size, with four roots and quadrate crowns, rather wider
transversely than from before backwards, each having four cusps,
connected by a pair of transverse ridges, anterior and posterior.
The first loAver premolar compressed in front ; the others composed
of a simple pair of transverse crests, with a small anterior and
posterior cingular ridge.
Skull elevated and compressed. Orbit and temporal fossa
widely continuous, there being no true postorbital process from
the frontal bone. Anterior narial apertures very large, and extend-
ing high on the face between the orbits ; nasal bones short, elevated,
1 See W. N. Parker, Proc. Zool. Soc. 1SS2, p. 775.
- Cuvier, Tableau fiUment. de VHist. Nat. p. 152 (1798) ; ex Brisson.
TAPIRID.K 371
triangular, and pointed in front. Vertebrae: C 7, 1) 18, L 5, S G,
C about 12. Limbs short and stout. Fore feet with four toes,
having distinct hoofs: the first is absent, the third the longest, the
second and fourth nearly equal, the fifth the shortest and scarcely
reaching the ground in the ordinary standing position. Hind feet
with the typical Perissodactyle arrangement of three toes, — the
middle one being the largest, the two others nearly equal. Nose
and upper lip elongated into a flexible, mobile snout or short pro-
boscis, near the end of which the nostrils are situated. Eyes rather
small. Ears of moderate size, ovate, erect. Tail very short. Skin
thick and but scantily covered with hair.
The existing species of Tapir may be grouped into two sections,
the distinctive characters of which are only recognisable in the
skeleton. (A) With a great anterior prolongation of the ossifica-
tion of the nasal septum (mesethmoid), extending in the adult far
beyond the nasal bones, and supported and embraced at the base
by ascending plates from the maxillae (genus Elasmognafhus, Gill).
Two species, both from Central America, Tapirus bairdi and T. dowi.
The former is found in Mexico, Honduras, Nicaragua, Costa Eica,
and Panama ; the latter in Guatemala, Nicaragua, and Costa Eica.
(B) "With ossification of the septum not extending farther forward
than the nasal bones (Tajyirus proper). Three species, T. indicus,
the largest of the genus, from the Malay Peninsula (as far north as
Tavoy and Mergui), Sumatra, and Borneo, distinguished by its
peculiar coloration, the head, neck, fore and hind limbs, being glossy
black, and the intermediate part of the body white ; T. amcrkaniis
(T. terresbris, Linn.), the common Tapir of the forests and lowlands
of Brazil and Paraguay (Fig. 152); and T. roidini, the Pinchaque
Tapir of the high regions of the Andes. All the American species
are of a nearly uniform dark brown or blackish colour when adult ;
but it is a curious circumstance that when young (and in this the
Malay species conforms with the others) they are conspicuously
marked with spots and longitudinal stripes of white or fawn colour
on a darker ground.
The habits of all the kinds of Tapirs appear to be very similar.
They are solitary, nocturnal, shy. and inoffensive, chiefly frequent-
ing the depths of shady forests and the neighbourhood of water, to
which they frequently resort for the purpose of bathing, and in
which they often take refuge Avhen pursued. They feed on various
vegetable substances, as shoots of trees and bushes, buds, and
leaves. They are hunted by the natives of the lands in which they
live for the sake of their hides and flesh.
The singular fact of the existence of so closely allied animals as
the Malayan and the American Tapirs in such distant regions of the
earth, and in no intervening places, is accounted for by what is
known of the geological history of the race ; for the Tapirs must
372
UNGULATA
once have had .a veiy wide distribution. There is no proof of their
having lived in the Eocene epoch, but in deposits of Miocene and
Pliocene date remains undistinguishable generically from the modern
Tapirs, and described as T. prisms, T. arvernensis, etc., have been
found in France, Germany, and in the Red Crag of Suffolk. Tapirs
appear, however, to have become extinct in Europe before the
Pleistocene period, since none of their bones or teeth have been found
in any of the caverns or alluvial deposits in which those of Elephants,
Rhinoceroses, and Hippopotamuses occur in abundance ; but in other
regions their distribution at this age was far wider than at present,
epur^^y-.agr-ttffci
Pio. 152. — The American Tapir (Tapirus americanus).
as they are known to have extended eastward to China (T. sinensis,
Owen) and westwards over the greater part of the southern United
States of America, from South Carolina to California. Lund also
distinguished two species or varieties from the caves of Brazil, one
of which appears identical with T. americanus. Thus we have no
difficulty in tracing the common origin in the Miocene Tapirs of
Europe of the now widely separated American and Asiatic species.
It is, moreover, interesting to observe how very slight an amount
of variation has taken place in forms isolated during such an
enormous period of time.
The anatomy of the soft parts of the Tapirs 1 conforms to the
1 See J. Murie, Journ. Anat. and Physiol, vol. vi. p. 131, 1871 ; W. N. Parker,
Proc. Zool. Soc. 1882, p. 768 ; and F. E. Beddard, Proc Zool. Soe. 18S9, p. 252.
LOPHIODONTin.K 373
general Perissodactyle type, as exemplified in the Rhinoceros and
the Horse, although on the whole (as might have been expected)
presenting a closer resemblance to the former. T. americanus
differs from T. indicus by the absence, or at any rate the less
development, of the intestinal valvuhe conniventes, the presence
of a moderator band in the heart, the shape of the glans penis,
and the more elongated caecum, which is sacculated by four dis-
tinct longitudinal fibrous bands. The convolutions of the hemi-
spheres of the brain of the Tapirs are simpler than in other Perisso-
dactyles, thus tending to confirm the inferences which may be drawn
from the skeleton and teeth as to the comparatively low or general-
ised organisation of these animals.
Palceotapirus. — This name has been applied to an imperfectly
known form from the Upper Eocene Phosphorites of Central France,
which is regarded by Dr. Filhol as referable to this family.
Family Lophiodontid^e.
Molars brachydont and bilophodont, those of the lower jaw with
either straight or imperfectly crescentoid ridges ; premolars smaller
and usually simpler than the molars ; last lower molar generally
with a third lobe. Outer columns of upper molars conical or
flattened. Digits usually as in the preceding family.
This family includes a number of more or less imperfectly
known forms, all of which are extinct and apparently confined to
the Eocene period, and ranging from the size of a Rabbit to that of
a Rhinoceros. Although some of these appear to have died out
without giving rise to more specialised forms, it is probable that this
family contained the ancestral types from which most or all of the
modern Perissodactyles have been derived. Only very brief mention
can be made here of some of the leading genera. Lophiodon, of the
Middle and Upper Eocene of Europe, with the dental formula,
* § > c h P § > m h includes the largest representatives of the family,
and is generally regarded as a stock which has died out without
giving rise to later forms. The ridges of the lower molars are
straight, and the last of these teeth has a third lobe ; while the
second transverse ridge of the last upper premolar is usually incom-
plete ; the outer columns of the upper molars are flattened, as in
the next genus. Hyrachyus, of the Upper Eocene of the United
States, and probably also occurring in the French Eocenes, is an
allied genus, with four premolars and no third lobe to the last lower
molar; the fourth upper premolar having the two ridges uniting
internally to form a crescent. This genus has been regarded as the
ancestor of the Rhinocerotic Hyracodon. The genus Hyracotherium
was established in 1839 by Owen for a small animal no larger than
a Hare, the skull of which was found in the London Clay at Heme
374
UNGULATA
Bay. A more nearly perfect specimen, apparently of the same species,
was afterwards (in 1857) described under the name of Pliolophus vulpi-
ceps, of which the skull is figured in the accompanying woodcut.
Other forms referable to the same genus have been obtained from
the Wasatch Eocene of the United States, and were described
by Professor Marsh under the name of Eohippus. There were four
premolars, the fourth being unlike the molars, and in the upper jaw
having only one inner cusp. The upper molars are of the general
type of those of Lophiodon, but have conical outer columns, and
the anterior transverse ridge imperfect, while the ridges of the
lower molars are crescentoid. Systemodon differs from Hyracotherium
Fig. 153.— Right side of skull of Hymcotherinum leporinum, from the London Clay, i natural
size. (After Owen.) 3, Occiput ; 7, sagittal crest ; 11, frontals ; 15, nasals ; 21, maxilla ; 22,
premaxilla; d, mandibular condyle ; o, aperture of facial nerve ; p 1-4, premolars ; to 1-3, molars.
by the absence of a diastema between the first and second pre-
molars ; it occurs in the Wasatch Lower Eocene of the United States.
In Pachynolophus (Lophiotherium, Orotherium, or Orohippus), which is
common to the Middle and Upper Eocene of Europe and the Bridger
Eocene of North America, the outer columns of the upper molars
are flattened, and in some cases, at least, the last premolar resembles
the molars, that of the upper jaw having two inner cusps. 1 This
genus, indeed, so closely connects Hyracotherium with the genera
Epihippus and Anchilophus as to show that the distinction between
the Lophiodontidce and Pakeotheriidce is really an arbitrary one.
Epihippus, of the Upper Eocene of the United States, has both the
third and fourth upper premolars as complex in the molars, and
is distinguished from Anchilophus by the lower cusps and more
imperfect transverse ridges of these teeth. The so-called Orohippus
agilis belongs to this genus. Isectolophus is another American Eocene
genus which may be provisionally placed in this family ; it is
regarded by Professors Scott and Osborn as connecting Systemodon
1 The Swiss P. sidcrolithicus has only one cusp in the last upper premolar.
PAL.i:ornERiin.E
375
with the Tapirid(B; the fourth and probably the third upper pre-
molar approximating in structure to the molars; the upper molars
have conical outer columns. Helaletes is another closely allied
form, with similar premolars, but with the outer columns of the
upper molars flattened.
Family Pal^otiieriid.e.
Molars (Fig. 155) brachydont, with the valleys between the
ridges never filled with cement ; upper premolars either simpler than
Fig. 154.— Restoration of Palceotherium (Upper Eocene). After Cuvier.
or as complex as the molars ; lower molars with crescentoid ridges,
and the last of the series with or without a third lobe. Outer
columns of upper molars flattened.
Orbit (at least usually) confluent
with temporal fossa. Three digits
on each foot. This family in-
cludes extinct genera ranging from
the Middle and Upper Eocene to
the Miocene, and passes so gradu-
ally into the following one that the
maintenance of the two can only
be supported on the ground of
convenience. The typical genus,
I'lihrotlierium, was made known to
science in the early part of the
present century by Cuvier, who
restored the skeleton (Fig. 154)
with a short neck like that of the
Tapirs, although it has been sub-
sequently found that the neck
was considerably longer. This
genus (Avhich may be taken to include Paloplotherium) ranges from
Fig. 155.— A half-worn right upper molar of
PaUeotherium magnum. (After Owen.) /, /,
External surfaces of outer columns ; a, postero-
external column (metacone) ; 6, antero - ex-
ternal column (paracone) ; c, postero-internal
column (hypoeone) ; d, antero-intemal column
(protocone); i, anterior intermediate column
(protoconule) ; e, median valley; g, posterior
valley.
376 UNGULATA
the Middle to the Upper Eocene of Europe, and usually has the full
typical dentition, although the first premolar may disappear. The
last lower molar has a third lobe ; and in the typical forms the last
premolar is as complex as the molars, the diastema is short, and the
canines are not large. In other forms, however, the hinder ridge of
the fourth upper premolar may be aborted. The first upper cheek-
tooth is generally a well -developed tooth, which may have a
deciduous predecessor. Anchilqphus, of the Upper Eocene of Europe,
and Anchitherium, of the Miocene of Europe and North Amei'ica,
connect the preceding forms with the Eqiticlce. In the latter genus
there is the full number of teeth, the last lower molar has almost
completely lost the third lobe of AnGhilophus, and the surfaces
of the two outer lobes of the upper molars (Figs. 157, 158) lack
the median vertical ridges of that genus. In the American
species of Anchitherium (which have been described as Mesohippus
and Miohippus) the lateral digits are larger than in the European
Middle Miocene Anchitherium a urelianense ; a mere splint represents
the fifth metacarpal, and the meso- and ento-cuneiform of the tarsus
do not unite as they do in the latter.
Family Equid.e.
Molars hypsodont, with the outer columns of the upper ones
flattened, the valleys completely filled with cement, and the enamel
thrown into folds and plications ; upper premolars as complex as
molars, which they slightly exceed in size ; ridges of lower molars
crescentoid, and complicated by enamel-foldings ; no distinct third
lobe to last lower molar; summits of incisors with a central infold-
ing of enamel. Orbit completely surrounded by bone. Digit s
three or one, but in the former case the median one is alone of
functional importance ; ulna and fibula incomplete ; meso- and ento-
cuneiform of tarsus united.
Such are the leading characters which serve to distinguish the
existing Horses and their nearest fossil allies from the Palceotheriidce.
The Horse, as being the best known of the Perissodactyle Ungu-
lates, is selected for a somewhat detailed description ; but before
proceeding to this it will be advisable to take a brief survey
of the relations of the Equidce to the extinct forms already
noticed, and also of the modifications of the family at present
existing.
The earliest form which can be certainly included in this line of
descent is the American Lower Eocene genus Phertacodus (noticed
below under the head of the suborder Condylarthra), in which
there were five complete digits to the feet. From this form there
is but a step to Systemodon and Hyracotherium, in which the func-
tional digits of the manus were reduced to four, as in Pachynolophus
EOUin.E
377
(Fig. L56, a), although one species retained a rudiment of the
metacarpal of the pollex.
The transit ion from these animals of the Eocene period to the
Horses of modern times has been accompanied by a gradual increase
in size. The diminutive Hyracotherium of the Lower, and Pdchy-
nolophus of the Middle and Upper Eocene were succeeded in the
Miocene period by the forms to which the name of Anchitherium
has been given, of the size of sheep; these again in Pliocene times
by Hipparion and Protohippus, as large as the modern donkeys; and
it is mainly in the Pleistocene period that Eqvidce occur which
approach in size the existing Horse. Important structural modi-
fications have also taken place, with corresponding changes in the
Fig. 150'.— Successive stages of modification of the feet of extinct forms of Horse -like
animals (chiefly from Marsh), showing gradual reduction of the outer and enlargement of the
middle toe (in), a, Pachynolophw (Eocene) ; 6, Anchitherium (Early Miocene) ; c, Anchitherium
(Late Miocene); d, Hipparion (Pliocene) ; e, Equus (Pleistocene).
mode of life of the animal. Thus the neck has become elongated,
the skull altered in form, the teeth greatly modified, and the limbs
have undergone remarkable changes. The last two recpiire to be
described more in detail.
The teeth in the Eocene forms had, as mentioned above, the
characteristic number of forty-four. This number has been retained
throughout the series, at least theoretically ; but one tooth on either
side of each jaw, the anterior premolar, which in all the Eocene
and Miocene species was well developed, persisting through the
lifetime of the animal, is in all modern Horses rudimentary,
functionless, and generally lost at an early period of life, evidently
passing through a stage which must soon lead to its complete dis-
appearance. The canines have also greatly diminished in size, and
are rarely present in the female sex, so that practically a very large
number of adult Horses of the present day have eight teeth less
than the number possessed by their predecessors. The diastema
or interval between . the incisor and premolar teeth (of essential
373
UNGULATA
importance in the domesticated Horse to his master, as without it
there would be no room for inserting the special instrument of
subjugation to his commands, the bit) already existed in the
earliest known forms, but has gradually increased in length. The
incisors have undergone in comparatively recent times that curious
change producing the structure more fully described hereafter,
which distinguishes the Horse's incisors from those of all other
known animals, with the exception of the extinct Macrauchenia.
Lastly, the molars have undergone a remarkable series of modi-
fications, much resembling in principle those that have taken place
in several other groups of herbivorous animals. Distinctions in
form which existed between the premolars, at least in the anterior
part of the series, and the true molars have gradually dis-
appeared, the teeth becoming all very uniform in the shape and
structure of their grinding surface. The crowns of all these teeth
Fig. 157. — a, Grinding surface of unworn molar tooth of Anchitherium ; b, corresponding
surface of unworn molar of young Horse ; c, the same tooth after it has- been some time in use.
The uncoloured portions are the dentine or ivory, the shaded parts the cement rilling the
cavities ami surrounding the exterior. The black line separating these two structures is the
enamel or hardest constituent of the tooth.
in the early forms were very short (see Fig. 158, a); there was a
distinct constriction, or neck, between the crown and roots ; and
when the tooth was developing, as soon as the neck once rose
fairly above the alveolar margin, the tooth remained permanently
in this position. The term " brachydont " expresses this condition
of teeth, the mode of growth of which may be illustrated by those
of man. The free surface had two nearly transverse curved ridges,
with valleys between (Fig. 157, a); but the valleys were shallow
and had no deposit of cement filling them, the whole exposed
surface of the unworn tooth being formed of enamel. When the
ridges became worn down the dentine of the interior was exposed,
forming islands surrounded by enamel. With the progress of time
the crowns of the teeth gradually became longer, the valleys deeper,
and the ridges not only more elevated but more curved and com-
plex in arrangement. To give support to these high ridges and
save them from breaking in use, the valleys or cavities between
them became filled up to the top with cement, and as the crown
wore down an admirable grinding surface consisting of patches and
EOUin.E
379
islands of the two softer substances, dentine and cement, separated
by variously reduplicated and contorted lines of intensely hard
enamel, resulted (Fig. 157, c). The crown continued lengthening
until in the modern Horses it has assumed the form called " hyps-
odont" (Fig. 158, b). Instead of contracting into a neck, and
forming roots, its sides continue parallel for a considerable depth in
tin 1 socket, and as the surface wears away, the whole
tooth slowly pushes up, and maintains the grinding
edge constantly at the same level above the alveolus,
much as in the perpetually growing Eodent's teeth.
But in existing Horses there is still a limit to the
growth of the molar. After a length is attained
which in normal conditions supplies sufficient grind-
ing surface for the lifetime of the animal,
a neck and roots are formed, and the
tooth is reduced to the condition of that
of the brachydont ancestor. It is per-
fectly clear that this lengthening of the
crown adds greatly to the power of the
teeth as organs of mastication, and en-
ables the animals in which it has taken fig. iss.— «, Outer view of second
place to find their sustenance among the ll ™' er raolar , t00 * h f ^^MtUriuw.
*■ , . Till! (brachydont form); 6, corresponding
comparatively dry and harsh herbage tooth of Horse (hypsodont form),
of the open plains, instead of being
limited to the more succulent vegetable productions of the marshes
and forests in which their predecessors probably dwelt.
The modifications of the limbs which took place pari passu with
those of the teeth must have been associated with increased speed,
especially over firm and unyielding ground. Short, stout legs, and
broad feet, with numerous toes, spreading apart from each other
when the Aveight of the creature is borne on them, are sufficiently
well adapted for plodding deliberately over marshy and yielding-
surfaces, and the Tapirs and the Rhinoceroses, which in the
structure of the limbs have altered but little from the primitive
Eocene forms, still haunt the borders of streams and lakes and
the shady depths of the forests, as was probably the habit of
their ancient representatives, while the Horses are all inhabitants of
the open plains, for life in which their whole organisation is in
the most eminent degree adapted. The length and mobility of
the neck, position of the eye and ear-, and great development of the
organ of smell, give them ample means of becoming aware of the
approach of enemies, w r hile the length of their limbs, the angles
the different segments form with each other, and especially the
combination of firmness, stability, and lightness in the reduction of
all the toes to a single one, upon which the Avhole weight of the
body and all the muscular power are concentrated, give them speed
38o
UNGULATA
and endurance surpassing that of almost any other animal. When
surprised, however, they are by no means helpless, both fore and
hind feet becoming at need powerful weapons of defence.
If we were not so habituated to the sight of the Horse as hardly
ever to consider its structure, we should greatly marvel at being-
told of a mammal so strangely constructed that it had but a single
toe on each extremity, on the end of the nail of which it walked or
galloped. Such a conformation is without a parallel in the vertebrate
series, and is one of the most remarkable instances of specialisation,
or deviation from the usual type, in accordance with particular
conditions of life. It is clear, both from the structure of the foot
itself, and also by an examination of the intermediate forms, that
this toe corresponds to the middle or third digit of the complete
typical or pentadactyle foot ; and there is very strong evidence to
show that by a gradual concentration of all the power of the limb
upon this toe, and the concurrent dwindling away and final dis-
appearance of all the others, the present condition of the Horse's
foot has been produced.
Protohippus. 1 — In this Lower Pliocene North American genus
(also described as Merychippus) the cheek-teeth resemble those of
the generalised species of Equus, but have shorter crowns ; while
the milk-molars approximate to the permanent molars of Anchi-
therium. Each foot has three digits.
HipparimiJ — Upper cheek-teeth (Fig. 159), with the antero-
c f
d i
Fig. 159.— Three right upper cheek-teeth of Hipparion. a, Antero-external column ; b,
postero-external column; c, postero-internal column, or posterior pillar; d, antero-internaJ
column, or anterior pillar ; /, posterior intermediate column ; i, anterior intermediate column.
(From the Palceontologia Indka.)
internal column, or anterior pillar as it may be conveniently termed
in this family, detached throughout the greater part of its height
from the adjacent column. Either a single or three digits in each foot.
First upper premolar large and persistent. This genus was very
widely distributed in the Pliocene, occurring in Europe, Asia, and
North America. In the typical European forms, and also in those
1 Lekly, Proc. Ac. Nat. Sci. Philad. 185S, p. 26.
2 Christol, Ann. Sci. Inclust. Mid. France, vol. i. p. 180 (1S32).
EQUID.K 3S1
of North America, there were three digits in the feet (Fig. 156, d);
but in the Indian II. antUopinum (separated by Cope as Hxppo-
dactylus) the lateral digits seem to have disappeared. There is
some doubt whether or no Hipparion should occupy a place in the
direct ancestry of the Horse, and Professor Cope suggests that while
in America the intermediate place between Anchitherium and Eqyms
was held by Protohippus, in Europe the same position was occupied
by Hipparion — a view which involves the dual origin of the Horses
of the New and Old Worlds.
Equus} — Upper cheek-teeth with the anterior pillar (except in
a very early stage of wear) joined by a narrow neck to the
adjacent column (Fig. 157, c). Each foot Avith a single complete
digit, but with remnants of the proximal portions of the second
and fourth metapodials (Fig. 156, e) ; some extinct forms having
clawdike rudiments of the terminal phalangeals of the lateral digits.
First upper premolar very small or altogether absent in existing
species, but in some fossil species larger and persistent ; first
lower premolar only occasionally developed in some fossil forms.
Ears long. Tail long, with long hairs either at the end or
throughout. A callosity on the inner side of the fore limb above
the carpus.
Fossil Species. — In the Pleistocene Horses of South America
described as Hippidium, as well as in the closely allied ones from
Xorth America for which the name Plioliippxis has been proposed,
the upper molars are shorter and more curved than in the existing
species, while their anterior pillar is not longer antero-posteriorly
than in Hipparion ; the lateral claw-like hoofs persisting. Some of
the European Pliocene species (like E. stenonis) agree with these
species in the form of the grinding surface of the anterior pillar
of the upper molars. In one of the species from the Lower
Pliocene of India (E. siralensis) — which was a contemporary of
Hipparion — and in all the existing species, the grinding surface of
the pillar in question is greatly elongated in the antero-posterior
direction, as in Fig. 157, c.
Fossil remains of Horses are found abundantly in deposits of
the most recent geological age in almost every part in America,
from Eschscholtz Bay in the north to Patagonia in the south. In
that continent, however, they became quite extinct, and no Horses,
either wild or domesticated, existed there at the time of the
Spanish conquest, which is the more remarkable as, when intro-
duced from Europe, the Horses that ran wild proved by their
rapid multiplication in the plains of South America and Texas that
the climate, food, and other circumstances were highly favourable
for their existence. The former great abundance of Eqmdce in
America, their complete extinction, and their perfect acclimatisation
1 Linn. Syst. Nat. 12th ed. vol. i. p. 100 (1766).
382 UNGULATA
when reintroduced by man, form curious but as yet unsolved
problems in geographical distribution.
Existing Species. — The existing species of the genus are the
following : —
The Horse, Equus caballus, is distinguished from the others by
the long hairs of the tail being more abundant and growing quite
from the base as well as the end and sides, and also by possessing
a small bare callosity on the inner side of the hind leg, just below
the " hock " or heel joint, in addition to the one on the inner side
of the fore limb above the carpus, common to all the genus. The
mane is also longer and more flowing, and the ears are shorter,
the limbs longer, the hoofs broader, and the head smaller.
Though the existing Horses are not usually marked in any
definite manner, or only irregularly dappled, or spotted with light
surrounded by a darker ring, many examples are met with showing
a dark median dorsal streak like that found in all the other
members of the genus, and even with dark stripes on the shoulders
and legs indicating "the probability of the descent of all the
existing races from a single dun-coloured, more or less striped,
primitive stock, to which our horses still occasionally revert." :
In Europe wild Horses were extremely abundant in the
Xeolithic or polished-stone period. Judging from the quantity of
their remains found associated with those of the men of that time,
the chase of these animals must have been among man's chief
occupations, and they must have furnished him with one of his
most important food supplies. The characters of the bones
preserved, and certain rude but graphic representations carved on
bones or reindeers' antlers, enable us to know that these Horses
were rather small in size, and heavy in build, with large heads and
rough shaggy manes and tails, much like, in fact, the present wild
horses of the steppes of the south of Russia. They were
domesticated by the inhabitants of Europe before the dawn of
history, but it is doubtful whether the majority of the animals now
existing on the Continent are derived directly from them, as it is
more probable that they are descendants from Horses imported
through Greece and Italy from Asia, derived from a still earlier
domestication, followed by gradual improvement through long-
continued attention bestowed on their breeding and training.
Horses are now diffused by the agency of man throughout almost
the whole of the inhabited parts of the globe, and the great modifica-
tions they have undergone in consequence of domestication and
selective breeding are well exemplified by comparing such extreme
forms as the Shetland pony, dwarfed by uncongenial climate, the
thoroughbred racer, and the London dray-horse. In Australia,
1 Darwin, Variation of Animals and Plants under Domestication, 1868, vol.
i. chap. ii.
EQcm.i: 383
as in America, horses imported by the European settlers have
escaped into the unreclaimed lands, and multiplied to a prodigious
extent, roaming in vast herds over the plains where no hoofed
animal ever trod before.
A wild Borse from Central Asia, named E. prezevalslcii, 1 is
described as having callosities on both limbs and broad hoofs like
E, caballus; but the long hairs of the tail do not begin until about
half way down its length. It also differs from E. cabalhts in having
a short erect mane and no forelock ; neither is there any dorsal
stripe. The ears are of moderate size ; the whole body is of a
whitish-gray, paler beneath, and reddish on the head and upper
parts of the limbs. If rightly described this form would appear
to be intermediate between the true Horses and the Asses.
The second species is the domestic Ass (E. asitms), and the wild
Asses of Africa (E. a sin us, var. africanus and var. somalicus 2 ). The
domestic Ass, which is now nearly as widely diffused and useful
to man as the Horse, was known in Egypt long before the latter,
and is doubtless of African origin. The ears are long, the mane
erect, the tail without long hairs at the base, and there are no
callosities on the hind limbs. There is a dark dorsal stripe, and
another across the shoulders ; while the limbs are frecpiently banded.
Of the wild forms the Xubian race (var. africanus) has distinct
dorsal and shoulder stripes, but the rings on the limbs are often very
indistinct ; while in the Somali race the dorsal stripe is indistinct,
and the shoulder stripe wanting, but the rings on the limbs are
very boldly marked. Teeth and bones from a Pleistocene cavern
deposit in Madras have been referred to E. asinus.
The Asiatic wild Asses, which roam in small herds in the open
plains of Syria, of many parts of Persia, of the north-west of India,
and the highlands of Tartary and Tibet, from the shores of the
Caspian to the frontiers of China, differ from the last in being of a
more rufous or isabelline colour, instead of pure gray, in wanting
the dark streak across the shoulder, and having smaller ears. They
have all a dark-coloured median dorsal stripe. Though it is con-
sidered probable by many zoologists that they form but a single
species 3 (E. hemionus), they present such marked variations in size
and form that they have commonly been divided into three — the
Syrian Wild Ass (E. hemippus), the Onager (E. onager) from Persia,
Baluchistan, the Punjab, Sind, and the desert of Kach, and the
Kiang or Dzeggetai (E. hemionus) of the high table-lands of Tibet,
where it is usually met with at an elevation of 15,000 feet and
upwards above the sea-level. The last is considerably larger than
1 See Nature, 21st August 1884, and Zool. Garten, vol. xxviii. p. 453.
- See Sclater, Proc. Zool. Soc. 1884, p. 542.
3 See Blanford, Zoology and Geology of Eastern Persia (Journeys of the Persia, 1
Boundary Commission), p. 84.
334
UNGULATA
either of the others, and differs from them in external appearance,
having more the aspect of the horse. They are all remarkably
swift, having been known to outstrip the fleetest Horse in speed.
Lastly, there are four striped species, all inhabitants of Africa.
These constitute the genus Hippotigris of Hamilton-Smith, but they
are not separable except by their coloration from the true Asses,
and one of them, the Quagga (E. quagga), may be considered as
intermediate. This animal Avas formerly met with in vast herds on
the great plains of South Africa, between the Cape Colony and the
Vaal River, but now, in common with most of the larger wild
animals of that region, is becoming extremely scarce, owing to the
Fig. 160.— The Quagga (Equus quagga).
encroachments of European civilisation, if, indeed, it is not already
extinct. In length of ears and character of tail it more resembles
the Horse than it does the Ass, although it agrees with the latter in
wanting the callosity on the inner side of the hind leg, just below
the hock, characteristic of the Horse. The colour of the head, neck,
and upper parts of the body is reddish-brown, irregularly banded
and marked with dark brown stripes, stronger on the head and
neck and gradually becoming fainter until lost behind the shoulder.
There is a broad dark median dorsal stripe. The under surface of
the body, the legs, and tail are nearly white, without stripes. The
crest is very high, surmounted by a standing mane, banded alter-
nately brown and white. Though never really domesticated,
Quaggas have occasionally been trained to harness. The accom-
panying figure is reduced from a painting made from one of a pair
which were driven in Hyde Park in the early part of the present
equid.i:
385
century. The name is an imitation of the shrill barking neigh of
the animal — "ouag-ga, ouag-ga," the last syllable very much pro-
longed. It must be remembered, however, in reading books of
African travel that the same word is very commonly applied by
hunters to Burehell's Zebra.
Of the Zebras proper, the one which was first known to Europeans,
and was formerly considered the most common, is the True Zebra
(A', zebra), sometimes called the Mountain Zebra. It inhabits the
mountainous regions of the Cape Colony ; but now, owing to the
advances of civilised man into its somewhat restricted range, it has
Fig. 101.— True or Mountain Zebra (Equus zebra).
become very scarce, and is even, like the Quagga, threatened with
extermination at no distant date. The second species, Burehell's
Zebra (E. bwrchetti), still roams in large herds over the plains to the
north of the Orange River, but in yearly diminishing numbers.
Both species are subject to considerable individual variations in
marking, but the following are the principal characters by which
the}" can be distinguished.
E. zebra (Fig. 161) is the smaller of the two (about 4 feet high
at the shoulders), and has longer ears, a tail more scantily clothed
with hair, and a shorter mane. The general ground colour is white,
and the stripes are black ; the lower part of the face is bright brown.
With the exception of the abdomen and the inside of the thighs, the
whole of the surface is covered with stripes, the legs having narrow
transverse bars reaching quite to the hoofs, and the base of the tail
25
336
UNGULATA
being also barred. The outsides of the ears have a white tip and
a broad black mark occupying the greater part of the surface, but
are white at the base. Perhaps the most constant and obvious
distinction between this species and the next is the arrangement
of the stripes on the hinder part of the back, where there are a
number of short transverse bands passing from the median longi-
tudinal dorsal stripe towards, and sometimes joining with, the
uppermost of the broad stripes which run obliquely across the
haunch from the flanks towards the root of the tail. There is often
a median longitudinal stripe under the chest.
Fig. 102. — Burchell's Zebra (Equus burchelli).
E. burchelli (Fig. 162) is a rather larger and more robust animal,
with smaller ears, a longer mane, and fuller tail. The general
ground colour of the body is pale yellowish-brown, the limbs nearly
white, the stripes dark brown or black. In the typical form they
do not extend on to the limbs or the tail ; but there is a great
variation in this respect, even in animals of the same herd, some
being striped quite down to the hoofs (this form has been named
E. chapmani). There is a strongly marked median longitudinal
ventral black stripe, to which the lower ends of the transverse side
stripes are usually united, but the dorsal stripe (also strongly
marked) is completely isolated in its posterior half, and the upper-
most of the broad haunch stripes runs nearly parallel to it. A
much larger proportion of the ears is white than in the other
species. In the middle of the wide intervals between the broad
EQUW.K 3S7
Mark stripes of the Hanks and haunches fainter stripes are generally
seen.
B. grevyi — Under this name a Zebra has been described which
was sent in L882 to Paris from the Galla country, lying to the
south of Abyssinia, the most northern locality in which Zebras have
previously been met with. In many of its characters it resembles
E. zebra, but the stripes are much finer and more numerous than in
the typical examples of that species, and it has a strong, black, and
isolated dorsal stripe. Even allowing for the great variations that
are met with in the markings of animals of this group, the aberrant
characters of this individual are quite sufficient to separate it specific-
ally from the true Zebra of South Africa. Other similar specimens
have been recently brought from the Somali country.
The flesh of the Zebras is relished by the natives as food, and their
hides are very valuable for leather. Although the many attempts
that have been made to break in and train these animals for riding
or driving have sometimes been rewarded with partial success, they
have never been domesticated in the true sense of the word.
There are thus at least seven modifications of the Horse type at
present existing, sufficiently distinct to be reckoned as species by
all zoologists, and easily recognised by their external characters.
They are, however, all so closely allied that each will, at least in a
state of domestication or captivity, breed with perfect freedom with
any of the others. Cases of cross breeds are recorded between the
Horse and the Quagga, the Horse and Burchell's Zebra, the Horse
and the Hemionus or Asiatic wild Ass, the common Ass and the
Zebra, the common Ass and Burchell's Zebra, the common Ass and
the Hemionus, the Hemionus and the Zebra, and the Hemionus and
Burchell's Zebra. The two species which are perhaps the farthest
removed in general structure, the Horse and the Ass, produce, as is
well known, hybrids or Mules, Avhich in some qualities useful to
man excel both their progenitors, and in some countries, and
for certain kinds of work, are in greater requisition than either.
Although occasional instances have been recorded of female Mules
breeding -with the males of one or other of the pure species, it is
doubtful if any case has occurred of their breeding inter se, although
the opportunities of doing so must have been great, as Mules have
been reared in immense numbers for at least several thousands of
years. We may therefore consider it settled that the different
species of the group are now in that degree of physiological differ-
entiation which enables them to produce offspring with each other,
but does not permit of the progeny continuing the race, at all events
unless reinforced by the aid of one of the pure forms.
The several members of the group show mental differences
quite as striking as those exhibited by their external form, and
more than perhaps might be expected from the similarity of their
388 UNGULATA
cerebral organisation. The patience of the Ass, the high spirit of
the Horse, the obstinacy of the Mule, have long been proverbial.
It is very remarkable that, out of so many species, two only should
have shown any aptitude for domestication, and that these two
should have been from time immemorial the universal and most
useful companions and servants of man, while all the others remain
in their native freedom to this day. It is, however, still a question
whether this really arises from a different mental constitution
causing a natural capacity for entering into relations with man, or
whether it may not be owing to their having been brought gradually
into this condition by long-continued and persevering efforts when
the need of their services was keenly felt. It is quite possible
that one reason why most of the attempts to add new species to
the list of our domestic animals in modern times have ended in
failure is that it does not answer to do so in cases in which existing
species supply all the principal purposes to which the new ones
might be put. It can hardly be expected that Zebras and Quaggas
fresh from their native mountains and plains can be brought into
competition as beasts of burden and draught with Horses and Asses,
Avhose naturally useful qualities have been augmented by the train-
ing of thousands of generations of progenitors.
Not unfrequently instances occur of domestic Horses being
produced with a small additional toe with complete hoof, usually on
the inside of the principal toe, and, though far more : rarely, three
or more toes may be present. These malformations are often cited
as instances of reversion to the condition of some of the earlier
forms of equine animals previously mentioned. Such explanations,
however plausible they appear at first sight, are nevertheless very
doubtful. All the feet of polydactyle horses which Ave have
examined bear little resemblance to those of Hipjxirion or Anchi-
therium, but look rather as if due to that tendency to reduplication
of parts which occurs so frequently as a teratological condition,
especially among domestic animals, and, whatever its origin, certainly
cannot in many instances, as the cases of entire limbs super-
added, or of six digits in man, be attributed to reversion.
Anatomy. — The anatomical structure of the Horse has been de-
scribed in great detail in several works devoted to the subject, which
will be mentioned in the bibliography, though these have generally
been written from the point of view of the veterinarian rather than
of the comparative anatomist. The limits of the present work will
only admit of the most salient points being indicated, particularly
those in which the Horse differs from the other Ungulata. Unless
otherwise specified, it must be understood that all that is stated
here, although mostly derived from observation upon the Horse,
applies equally well to the other existing members of the group.
Skeleton. — The skull (Fig. 163) as a whole is greatly elongated,,
EQUIDsE
3§9
chiefly in consequence of the immense size of the face as compared
with the hinder or true cranial portion. The basal line of the
cranium from the lower border of the foramen magnum to the
incisor border of the palate is very nearly straight. The orbit, of
nearly circular form, though small in proportion to the size of the
whole skull, is distinctly marked, being completely surrounded by a
strong ring of bone with prominent edges. Behind it, and freely
communicating with it beneath the osseous bridge (the postorbital
£S&
^K^P>
>V<-V* 3
Fig. 163. — Side view of skull of Horse, with the bone removed so as to expose the whole of
the teeth. PMx, Premaxilla ; Mx, maxilla ; Ka, nasal ; Ma, malar or jugal ; L, lachrymal ; Fr,
frontal ; Sq, squamosal ; Pa, parietal ; oc, occipital condyle ; pp, paroccipital process ; i 1 , i 2 ,
and >'■', the three incisors ; c, the canine ; pin\ the situation of the rudimentary first premolar,
which has been lost in the lower, but is present in the upper jaw ; pm-, pnfi, and pm*, the
three fully developed premolars ; m 1 , »i 2 , and m 3 , the three true molars.
process of the frontal) forming the boundary between them, is the
small temporal fossa occupying the whole of the side of the cranium
proper, and in front is the great flattened expanse of the " cheek,"
formed chiefly by the maxilla, giving support to the long row of
cheek-teeth, and having a prominent ridge running forward from
below the orbit for the attachment of the masseter muscle. The
lachrymal occupies a considerable space on the flat surface of the
cheek in front of the orbit, and below it the jugal or malar does
the same. The latter sends a horizontal or slightly ascending-
process backwards below the orbit to join the under surface of the
zygomatic process of the squamosal, which is remarkably large, and,
instead of ending as usual behind the orbit, runs forwards to join
the greatly developed postorbital process of the frontal, and even
39o UNGULATA
forms part of the posterior and inferior boundary of the orbit, an
arrangement not met with in other mammals. The closure of the
orbit behind distinguishes the skull of the Horse from that of the
Rhinoceros and Tapir, and also from all of the Perissodactyles of
the Eocene period. In front of the cerebral cavity, the great
tubular nasal cavities are provided with well-developed turbinal
bones, and are roofed over by very large nasals, broad behind, and
ending in front in a narrow decurved point, The opening of the
anterior nares is prolonged backwards on each side of the face
between the nasals and the elongated slender premaxUlse. The
latter expand in front, and are curved downwards to form the semi-
circular alveolar border supporting the large incisor teeth. The
palate is narrow in the interval between the incisor and cheek-
teeth, in which are situated the large anterior palatine foramina.
Between the cheek-teeth it is broader, and it ends posteriorly in a
rounded excavated border opposite the hinder edge of the penulti-
mate molar. It is mainly formed by the maxilla?, as the palatines
are very narrow. The pterygoids are delicate slender slips of bone
attached to the hinder border of the palatines, and supported
externally by, and generally ankylosed to, the rough pterygoid
plates of the alisphenoid, with no pterygoid fossa between. They
slope very obliquely forwards, and end in curved, compressed,
hamular processes. There is a distinct alisphenoid canal for the
passage of the internal maxillary or main branch of the external
carotid artery. The base of the cranium is long and narrow ; the
alisphenoid is very obliquely perforated by the foramen rotundum,
but the foramen ovale is confluent with the large foramen lacerum
medium behind. The glenoid surface for the articulation of the
mandible is greatly extended transversely, concave from side to
side, convex from before backwards in front, and hollow behind, and
is bounded posteriorly at its inner part by a prominent postglenoid
process. The squamosal enters considerably into the formation of
the temporal fossa, and, besides sending the zygomatic process for-
wards, it sends down behind the meatus auditorius a post-tympanic
process which aids to hold in place the otherwise loose tympano-
periotic bone. Behind this the exoccipital gives off a very long
paroccipital process. The periotic and tympanic are ankylosed
together, but not with the squamosal. The former has a wide but
shallow floccular fossa on its inner side, and sends backwards a
considerable " pars mastoidea," which appears on the outer surface
of the skull between the post-tympanic process of the squamosal and
the exoccipital. The tympanic forms a tubular meatus auditorius
externus directed outwards and slightly backwards. It is not
dilated into a distinct bulla, but ends in front in a pointed styliform
process ; and completely embraces the truncated cylindrical tym-
panohyal, which is of great size, in correspondence with the large
EQUID.K 391
development of the whole anterior arch of the hyoid. This con-
sists mainly of a long and compressed stylohyal, expanded at the
upper end, where it Bends off a triangular posterior process. The
basihyal is remarkable for the long, median, pointed, compressed
" glossohyal " process, which it sends forward from its anterior
border into the base of the tongue. A similar but less developed
process is found in the Rhinoceros. The mandible is largely
developed, especially the region of the angle, which is expanded
and flattened, giving great surface for the attachment of the
masseter muscle. The condyle is greatly elevated above the
alveolar border ; its articular surface is very wide transversely, and
narrow and convex from before backwards. The coronoid process
is slender, straight, and inclined backwards. The horizontal ramus,
long, straight, and compressed, gradually narrows towards the
svmphysis, where it expands laterally to form with the ankylosed
opposite ramus the wide, semicircular, shallow alveolar border for
the incisor teeth.
The vertebral column consists of seven cervical, eighteen dorsal,
six lumbar, five sacral, and fifteen to eighteen caudal vertebra?.
There may be nineteen rib-bearing vertebrse, in which case five
only will be reckoned as belonging to the lumbar series. The
odontoid process of the atlas is wide, flat, and hollowed above, as
in the Ruminants. The bodies of the cervical vertebra} are elon-
gated, strongly keeled, and markedly opisthoccelous, or concave
behind and convex in front. Their neural lamina? are very broad,
the spines almost obsolete, except in the seventh, and the trans-
verse processes not largely developed. In the trunk vertebras the
opisthoccelous character of the centrum gradually diminishes. The
spinous processes of the anterior thoracic region are high and com-
pressed. To these is attached the powerful elastic ligament,
ligamentum nucha, or "paxAvax," which passing forwards in the
middle line of the neck above the neural arches of the cervical ver-
tebra?, to which it is also connected, is attached to the occiput and
supports the weight of the head. The transverse processes of the
lumbar vertebra? are long, flattened, and project horizontally out-
wards or slightly forwards from the arch. The metapophyses are
moderately developed, and there are no anapophyses. The caudal
vertebra?, except those quite at the base, are slender and cylindrical,
without processes and without chevron-bones beneath. The ribs
are eighteen or nineteen in number on each side, flattened, and
united to the sternum by short, stout, tolerably well ossified sternal
ribs. The sternum consists of six pieces ; the anterior or pre-
sternum being extremely compressed, and projecting forwards like
the prow of a boat. The segments which follow gradually widen,
and the hinder part of the sternum is broad and flat.
As in all other Ungulates, there are no clavicles. The scapula
392 UNGULATA
is long and slender ; the suprascapular border is rounded, and
slowly and imperfectly ossified. The spine is very slightly devel-
oped ; rather above the middle its edge is thickened and somewhat
turned backwards, but it gradually subsides at the lower extremity
without forming any acromial process. The coracoid process is a
prominent rounded nodule. The humerus is stout and rather
short, and has a double bicipital groove. The ulna is quite rudi-
mentary, being only represented by little more than the olecranon.
The shaft gradually tapers below, and is firmly ankylosed to the
radius. The latter bone is of nearly equal width throughout. The
three bones of the first row of the carpus (the scaphoid, lunar, and
cuneiform) are subequal in size. The second row consists of a very
broad and flat magnum, supporting the great third metacarpal,
having to its radial side the trapezoid, and to its ulnar side the unci-
form, which are both small, and articulate distally with the rudi-
mentary second and fourth metacarpals. The pisiform is large and
prominent, flattened, and curved ; articulating partly with the
cuneiform and partly with the lower end of the radius. The large
metacarpal is called in veterinary anatomy "cannon-bone"; the
small lateral metacarpals, which gradually taper towards their
lower extremities, and lie in close contact with the large one, are
called " splint-bones." The single digit consists of a moderate-sized
proximal (os suffmginis, or large pastern), a very short middle (os
coronce, or small pastern), and a wide, semi-lunar, ungual -phalanx
(os pedis, or coffin-bone). There is a pair of large nodular sesamoids
behind the metacarpophalangeal articulation, and a single large
transversely extended sesamoid behind the joint between the
second and third phalanx, called the " navicular bone." :
The carpal joint, corresponding to the wrist of man, is commonly
called the "knee" of the Horse, the joint betAveen the metacarpal
and the first phalanx the " fetlock," that between the first and
second phalanges the " pastern," and that between the second and
third .phalanges the " coffin-joint."
In the hind limb the femur is marked, as in other Perisso-
dactyles, by the presence of a " third trochanter," a flattened process,
curving forwards, arising from the outer side of the bone, about
one-third of the distance from the upper end. The fibula is reduced
to a mere styliform rudiment of the upper end ; its loAver part being-
absent or completely fused with the tibia. The calcaneum has a
long and compressed calcaneal process. The astragalus has a large
flat articular surface in front for the navicular, and a very small one
for the cuboid. The navicular and the external cuneiform bones
are very broad and flat. The cuboid is small, and the internal and
middle cuneiform bones are small and united together. The meta-
podials and phalanges resemble very closely those of the fore limb,
1 This must not be confounded with the navicular of the tarsus.
EQUID.E
393
hut the principal metatarsal is more laterally compressed at its
upper end than is the corresponding metacarpal. The joint
between the femur and tibia, corresponding to the knee of man, is
called the "stifle joint "; while that between the tibia and tarsus,
corresponding to the ankle of man, is termed the "hock." The
hones and joints of the foot have the same names as in the fore
limb. The Horse is eminently " digitigrade," standing on the ex-
tremity of the single digit of each foot, which is kept habitually in
a position approaching to vertical.
The muscles l of the limbs are modified from those of the ordi-
nary mammalian type in accordance with the reduced condition of
the hones and
i
the simple re-
quirements of
flexion and ex-
tension of the
joints, no such
actions as pro-
nation and
supination, or
opposition of
digits, being-
possible or
needed. The
muscles, there-
fore, which per-
forra these
functions in
other mammals
are absent or
rudimentary.
Below the
carpal and tar-
sal joints the
fore and hind
limbs corre-
spond almost
exactly in struc-
ture as well as function. On the anterior or extensor surface of
the limb a powerful tendon (7 in Fig. 164), that of the anterior
extensor of the phalanges (corresponding to the extensor communis
digitorum of the arm and extensor longus digitorum of the foot of man)
passes down over the metacarpal bone and phalanges, to be inserted
mainly into the upper edge of the anterior surface of the last phalanx
1 "Want of space and of the necessary illustrations rendered it impossible to
give an account of mammalian myology in the earlier chapters of this work.
Fig. 164.— Section of foot of Horse. 1, Metacarpal bone ; 2, first
phalanx (ps suffraginis) ; 3, second phalanx (os corona); 4, third or
ungual phalanx (os pedis, or coffin-bone) ; 5, one of the upper sesamoid
bones; 6, lower sesamoid or "navicular" bone; 7, tendon of anterior
extensor of the phalanges ; 8, tendon of superficial flexor (fl. perforatus) ;
9, tendon of deep flexor (fl. perforans); 10, suspensory ligament of
fetlock ; 11, inferior or short sesamoid ligament ; 12, derma or skin
of the foot, covered with hair, and continued into 13, the coronary
cushion, 14, the podophyllous or laminar membrane, and 15, the kera-
togenous membrane of the sole ; 16, plantar cushion ; IT, hoof; IS, fatty
cushion of fetlock.
394 UN GU LATA
or pedal bone. There is also a much smaller second extensor on
the outer side of this in each limb, the lateral extensor of the
phalanges. In the fore leg the tendon of this muscle (which corre-
sponds with the extensor minimi digiti of man) receives a slip from
that of the principal extensor, and is inserted into the first phalanx.
In the hind leg (where it is the homologue apparently of the
peroneus brevis of man) the tendon becomes blended with that of the
large extensor.
A very strong ligamentous band behind the metapodium,
arising from near the upper extremity of its posterior surface,
divides into two at its lower end, and each division, being first
connected with one of the paired upper sesamoid bones, passes by
the side of the first phalanx to join the extensor tendon of the
phalanges. This is called in veterinary anatomy the " suspensory
ligament of the sesamoids," or of the " fetlock " (10 in Fig. 164) ; but
its attachments and relations, as well as the occasional presence of
muscular fibres in its substance, show that it is the homologue of
the short flexor muscle of other mammals, curiously modified both
in structure and function to suit the requirements of the Horse's
foot. Behind or superficial to this are placed the two strong tendons
of the long flexor muscles, the most superficial, or flexor perforotus
(8), dividing to allow the other to pass through, and then inserted
into the middle phalanx. The flexor perforans (9) is as usual in-
serted into the terminal phalanx. In the fore leg these muscles
correspond with those similarly named in man. In the hind leg,
the perforated tendon is a continuation of that of the plantaris,
passing pulley -wise over the tuberosity of the calcaneum. The
perforating tendon is derived from the muscle corresponding with
the long flexor of man, and the smaller tendon of the oblique flexor
(tibialis posticus of man) is united Avith it.
The hoof of the Horse corresponds to the nail or claw of other
mammals, but is so constructed as to form a complete and very
solid case to the expanded termination of the toe, giving a firm
basis of support formed of a nonsensitive substance, which is con-
tinually renewed by the addition of material from within as its
surface wears away by friction against the ground. The terminal
phalanx of the toe is greatly enlarged and modified in form to sup-
port this hoof, and the size of the internal framework of the foot is
further increased by a pair of lateral fibro- cartilaginous masses
attached on each side to the hinder edges of the bone, and by a
fibro-cellular and adipose plantar cushion in the median part.
These structures are all enclosed in the keratogenous membrane or
" subcorneous integument," a continuation of the ordinary derma of
the limb, but extremely vascular, and having its superficial extent
greatly increased by being developed into papilla? or laminae. From
this the horny material which constitutes the hoof is exuded. A
EQUID.K 395
thickened ring encircling the upper part, called coronary cushion
(13), and the sole (1~>), are covered with numerous thickly set
papillae or villi, and take the greatest share in the formation of the
hoof; the intermediate part constituting the front and side of the
foot (14), corresponding with the wall of the hoof, is covered with
parallel, fine longitudinal laminae, fitting into corresponding depres-
sions in the inner side of the horny hoof.
The horny hoof is divided into a wall or crust consisting of the
front and sides, the flattened or concave sole, and the "frog," a
triangular median prominence, notched posteriorly, with the apex
turned forwards, situated in the hinder part of the sole. It is
formed of pavement epithelial cells, mainly grouped in a concentric
manner around the vascular papilla? of the keratogenous membrane,
so that a section near the base of the hoof, cut transversely to the
long axis of these papilla?, shows a number of small circular or oval
orifices, with cells arranged concentrically round them. The nearer
the surface of the hoof, or farther removed from the seat of growth,
the more indistinct the structure becomes.
Small round or oval plates of horny epidermis called " chest-
nuts," growing like the hoof from enlarged papilla? of the skin, are
found on the inner face of the fore limb, above the carpal joint, in
all species of Equidce, and in the Horse {E. caballus) alone similar
formations occur near the upper extremity of the inner face of the
metatarsus. Their use is unknown.
Behind the joint between the metapodium and the first phalanx
is a prominence formed by the fatty cushion of the fetlock (18 in
Fig. 164). On the middle of this is a small bare patch covered
with thickened epidermis, the ergot or spur, generally concealed
beneath the long hair which grows around it. This is the function-
less vestige of the large callous pad found in this situation in the
Tapir, and in fact in all mammals in which this part reaches the
ground in walking.
Dentition. — The dentition of the Horse, when all the teeth are
in place, is, as stated before, expressed by the formula i f , c \, p •§>
m| = 42. The incisors of each jaw are placed in close contact,
forming a semicircle. The crowns are broad, somewhat awl-
shaped, and of nearly ecpial size. They have all the great peculi-
arity, not found in the teeth of any other living mammal, of an
involution of the external surface of the tooth (see Fig. 165)
forming a deep fossa or pit, the bottom of Avhich becomes partially
filled up with cement. As the tooth wears, the surface, besides
the external enamel layer as in an ordinary simple tooth, shows
in addition a second inner ring of the same hard substance sur-
rounding the pit, thus of course adding greatly to the efficiency
of the tooth as an organ for biting tough, fibrous substances. This
pit, generally filled in the living animal with particles of food, is
396
UNGULATA
conspicuous from its dark colour, and constitutes the " mark " by
which the age of the horse is judged, as in consequence of its
extending only to a certain depth, it becomes obliterated as the
crown wears away, when the tooth assumes the character of an
ordinary incisor, consisting only of a core of dentine surrounded
by the external enamel
layer. It is not quite so
deep in the lower as in
the upper teeth. The
canines are either quite
rudimentary or entirely
absent in the female. In
the male they are com-
pressed, pointed, and
smaller than the incisors,
from which they are
separated by a slight in-
terval. The teeth of the
cheek series are all in
contact with each other,
but separated from the
canines by a considerable
toothless space. The
anterior premolars are
Pig. 105.— Longitudinal and transverse section of upper quite rudimentary, often,
incisor of Horse, p, Pulp cavity ; d, dentine or ivory ; e, especially ill the lower
enamel ; c, outer layer of cement ; c', inner layer of cement, . , , ■■ , ,,
lining a, the pit or cavity of the crown of the tooth. ] aW J not developed at all,
and generally fall by the
time the animal attains maturity, so that there are but six func-
tional grinding teeth — three that have predecessors in the milk-
dentition, and hence are considered as premolars, and three true
molars, but otherwise, except the first and last of the series,
not distinguishable in form or structure. These teeth in both
upper and lower jaws are extremely long-crowned or hypsodont
(Fig. 158), successive portions being pushed out as the sur-
face wears aAvay ; — a process which continues until the animal
becomes advanced in age. The enamelled surface is infolded in a
complex manner (a modification of that found in other Perissodac-
tyles, see Figs. 155, 167), the folds extending quite to the base of
the crown, and the interstices being filled and the surface covered
with a considerable mass of cement, which binds together and
strengthens the whole tooth. As the teeth wear, the folded enamel,
being harder than the other constituents — the dentine and cement
— forms projecting ridges on the surface arranged in a definite
pattern, which give it great efficiency as a grinding instrument (see
Fig. 157, b and c). The free surfaces of the upper teeth are
EQUIDjE
397
quadrate, except the first and last, which are nearly triangular.
The lower teeth are much narrower than the upper.
The milk dentition consists of i |, c #, m § = 24, — the canines
and first or rudimentary premolars having apparently no pre-
decessors. In form and structure they much resemble the
permanent teeth, having the same characteristic enamel -foldings.
Their eruption commences a few days after birth, and is complete
before the end of the first year, the upper teeth usually appear-
ing somewhat earlier than those of the lower jaw. The first
teeth to appear are the first and second milk-molars (about
five days), then the central incisor (from seven to ten days) ; this
is followed by the second incisor (at one month), then by the third
molar, and finally by the third incisor. Of the permanent teeth the
first true molar appears a little after the end of the first year,
followed by the second molar before the end of the second year. At
about two and a half years the first premolar replaces its predecessor.
Between two and a half and three years the first incisor appears.
At three years the second and third premolars and the third true
molar have appeared ; at from three and a half to four years the
second incisor ; at four to four and a half years the canine ; and,
finally, at five years the third incisor, completing the permanent
dentition. Up to this period the age of the horse is clearly shown
by the state of the dentition, and for some time longer indications
can be obtained from the wear of the incisor teeth, though this
depends to a certain extent upon the hardness of the food or other
accidental circumstances. As a general rule, the depression caused
by the infolding of the surface of the incisor (the " mark ") is
obliterated in the first or central incisor at six years, in the second
at seven years, and in the third at eight years. In the upper teeth,
as the depressions are deeper, this obliteration does not take place
until about two years later. After this period no certain indica-
tions can be obtained of the age of the horse from the teeth.
Digestive Organs. — The lips are flexible and prehensile.
membrane that lines them and the cheeks is quite smooth.
palate is long and narrow; its mucous surface has seventeen
of not very sharply defined oblique ridges, extending as far back as
the last molar tooth, beyond which the velum palati extends for
about 3 inches, having a soft corrugated surface, and ending
posteriorly in an arched border without uvula. This embraces the
base of the epiglottis, and shuts off all communication between
the cavity of the mouth and the nasal passages, respiration
under ordinary circumstances, carried on exclusively
nostrils. Between the mucous membrane and
the hard palate is a dense vascular and nervous
The
The
pairs
being,
through
the
the bone of
plexus. The
An elongated raised glandular mass, 3 inches long and 1 inch from
is a
membrane lining the fauces is soft and corrugated.
398 UNGULATA
above downwards, extending backwards from the root of the tongue
along the side of the fauces, with openings on the surface leading
into crypts -with glandular walls, represents the tonsil. The tongue,
corresponding to the general form of the mouth, is long and narrow.
It consists of a compressed intermolar portion with a flat upper
surface, broad behind and becoming narrower in front ; and of a
depressed anterior part rather shorter than the former, which
is narrow behind but widens towards the evenly rounded apex.
The dorsal surface generally is very soft and smooth. There are
two large circumvallate papillae near the base, rather irregular in
form, about a quarter of an inch in diameter and half an inch apart.
The conical papillae are very small and close set, though longer and
more filamentous on the intermolar portion. There are no fungi-
form papillae on the dorsum, but a few not very conspicuous ones
scattered along the sides of the organ.
Of the salivary glands the parotid is by far the largest; elongated
in the vertical direction, and narrower in the middle than at either
upper or lower extremity. Its upper extremity embraces the lower
surface of the cartilaginous ear-conch ; its lower end reaches the
level of the inferior margin of the mandible, along the posterior
margin of which it is placed. Its duct leaves the inferior anterior
angle, at first descends a little, and runs forward under cover of
the rounded inferior border of the mandibular ramus, then curves
up along the anterior margin of the masseter muscle, becoming-
superficial, pierces the buccinator, and enters the mouth by a simple
aperture opposite the middle of the crown of the third premolar
tooth. It is not quite so thick as a goose-quill when distended, and
nearly a foot in length.
The submaxillary gland is of very similar texture to the last,
but much smaller ; it is placed deeper, and lies with its main axis
horizontal. It is elongated and slender, and flattened from within
outwards. Its posterior end rests against the anterior surface of
the transverse process of the atlas, from which it extends forwards
and downwards, slightly curved, to beneath the ramus of the jaw.
The duct which runs along its upper and internal border passes
forwards in the usual course, lying in the inner side of the sublingual
gland, to open on the outer surface of a distinct papilla, situated
on the floor of the mouth, half an inch from the middle line, and
midway between the lower incisor teeth and the attachment of the
fraenum linguae. The sublingual is represented by a mass of glands
lying just beneath the mucous membrane of the floor of the mouth
on the side of the tongue, causing a distinct ridge, extending from
the fraenum backwards, and the numerous ducts opening separately
along the summit of the ridge. The buccal glands are arranged
in two rows parallel with the molar teeth. The upper ones
are the largest, and are continuous anteriorly with the labial
EQUIDuE 399
glands, the ducts of which open on the mucous membrane of the
upper lip.
The stomach of the Horse is simple in its external form, with
a largely developed right ad de s«<\ and i.s a good deal curved
on itself, so that the cardiac and pyloric orifices are brought near
together. The antrum pyloricum is small and not very distinctly
marked off. The interior is divided by the character of the lining
membrane into two very distinct portions, right and left. Over
the latter the dense white smooth epithelial lining of the oesophagus
is continued, terminating abruptly by a raised crenellated border.
Over the right part (rather the larger portion) the mucous membrane
has a grayish-red colour and a velvety appearance, and contains very
numerous peptic glands, which are wanting in the cardiac portion.
The oesophageal orifice is very small, and is guarded by a strong
crescentic or rather horse-shoe-like band of muscular fibres, which is
supposed to be the cause of the difficulty of vomiting in the Horse.
The small intestine is of great length (80 to 90 feet), its mucous
membrane being covered with numerous fine villi. The caecum is
of conical form, about 2 feet long and nearly a foot in diameter ;
its walls are sacculated, especially near the base, having four longi-
tudinal fibrous bands ; and its capacity is about twice that of the
stomach. It lies with its base near the lower part of the abdomen,
and its apex directed towards the thorax. The colon is about one-
third the length of the small intestine, and very capacious in the
greater part of its course. As usual, it may be divided into an
ascending, transverse, and descending portion ; but the middle or
transverse portion is folded into a great loop, which descends as low
as the pubis ; so that the colon forms altogether four folds, generally
parallel to the long axis of the body. The descending colon is much
narrower than the rest, and not sacculated, and being considerably
longer than the distance it has to traverse, is thrown into numerous
folds.
The liver (Fig. 166) is tolerably symmetrical in its general
arrangement, being divided nearly equally into segments by a well-
marked umbilical fissure. Each segment is again divided by lateral
fissures, which do not extend quite to the posterior border of the
organ ; of the central lobes thus cut off, the right is rather the larger,
and has two fissures in its free border subdividing it into lobules.
The extent of these varies, however, in different individuals, being
not usually so marked as in the figure, which is from a foetal
specimen. The two lateral lobes are subtriangular i 
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