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Full text of "An introduction to the study of mammals living and extinct"

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CORNELL UNIVERSITY. 



THE 
THE GIFT OF 

ROSWELL P. FLOWER 

FOR THE USE OF 

THE N. Y. STATE VETERINARY COLLEGE. 

1897 



Cornell University Library 
QL 701.F64 
An introduction to the study o| mammals 



3 1924 001 022 684 





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http://www.archive.org/details/cu31 924001 022684 



AN INTRODUCTION 



TO THE 



STUDY OF MAMMALS 



, ^^d 



AN INTEODUCTION 



TO THE STUDY OF 



M A M M A L S 



LIVING AND EXTINCT 



WILLIAM HENEY FLOWEE 

C.B., F.E.S., D.C.L., LL.D., P.Z.S., P.L.S., F.G.S., &r. 

DIRECTOR OK THE NATURAL HlbTORV DEFART_MEXT,S, BRITISH SlUSEl'M 
AND 

EICHAED LYDEIvKEE 

B.A., F.Ct.S., F.Z.S., &r. 




THE WOOLLY urO^iSl'M 



LONDON: ADAM AND CHAELES BLACK 
MDCCCXCl 



70/ 
r6^ 



H-.4-noutA_. 





PKEFACE 

One 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 selectioh 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 



PREFACE 



replace some whicli 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.E.S., 
as well as the articles "Mole," "Shrew," and "Vampyre," by the 
same writer, the articles "Marmot," "Mouse," "Opossum," "Phal- 
anger," "Eat," "Squirrel," "Stoat," "Vole," and others, by Mr. 
Oldfield Thomas, and likewise the article "Ape," by Dr. St. G. 
Mivart, F.E.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 
as 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 subsecjuent 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 1891. 



Corrigenda. 

Page 280, for Chwropsis read, Chceropsis. 

Page 292, for ClueropotamidEe and Cliifiropotamus read Chojropotamidfe and 
Chcei'opotauius. 

Page 590, for Piecilogale read Pcecilogale. 



CONTENTS 



CHAPTEE 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. 

CHAPTEE II 

General Anatomical Characters . . . . 7 

I. Tegumentary Structures .... 7 

Hair, 7; Colour, 8; Scales, etc., 11; ITails, 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 vertebrse, 41 ; Dorsal vertebrae, 42 ; 
Lumbar vertebra, 42 ; Sacral vertebrae, 43 ; Caudal vertebrae, 
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, 
56 ; Stomach, 57 ; Intestinal canal, 59 ; Liver, 60. 

V. Circulatory, Absorbent, Respiratory, and Urinary Systems 63 

Blood, 63 ; Heart, 63 ; Lymphaitic vessels, 65 ; Ductless 
glands, 65 ; Nostrils, 66 ; Trachea, 67 ; Larynx, 67 ; Diaphragm, 
67 ; Lungs, 68 ; Air-sacs, 68 ; Urinary Organs, 69 ; Bladder, 69. 



CONTENTS 



VI. Nervous System and Organs of Sense . . . %^ 

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. 

CHAPTER III 

Origin and Classification of the Mammalia . . 82 

Origin, 82 ; Classification, 84 ; Table of orders and 
families, 88. 

CHAPTER IV 

Geographical and Geological Distkibdtion . . 93 

I. Geographical Distribution . . . .93 

Zoological regions, 96 ; Palfearctic region, 97 ; Ethiopian 
region, 98; 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- 
tuberculataj 109 ; Polyprotodont types, 113 ; Tertiary mammals, 
115. 

CHAPTER V 

The Subclass Phototheria or Orniihodelphia . . 117 

General characters, 117. FaTtiily Oknithoehtnohid*, 
119 ; Ornithorhynchus, 119. Family ECHIDNID^, 124 ; 
Echidna, 125 ; Proechidna, 126 ; Fossil species, 127. 

CHAPTER VI 

The Subclass Metatheria or Didelphia . . .128 

General characters, 128 ; Distribution, 131 ; Classification, 
131. 

Suborder Poltprotodontia . . . . .133 

Family D1DELPHYID.E, 133 ; Ohii-07uicles, 134 ; Didelphys, 
135. Family Dasytjrid^, 136 ; Subfamily Dasyurinse, 136 ; 
Thylacinus, 136 ; Sarcophilus, 137 ; Dasyunis, 138 ; Phascolo- 
gale, 139 ; Sminthopsis, 139 ; Antechinomys, 139 ; Subfamily 
Myrmecobiinfe, 140; Myrmecobius, 140. Family V^utM.TSi.YDS., 
141 ; Perameles, 142 ; Peragale, 143 ; Chceropus, 143. 



CONTENTS 



PAGE 

Suborder Diprotodontia . . . . .144 

Family Phascolomyid^, 144 ; Phascolomys, 145 ; Phascol- 
omis,li6. JTaimiZi/PHALANGEKiD^,147; Subfamily TiLrsi])edmse, 
148 ; Tarsipes, 148 ; Subfamily PhalangerinEe, 149 ; Fhalanger, 
149 ; Trichosurus, 150 ; Fseudochirus, 151 ; Fetauroides, 152 ; 
Dadylopsila, 152 ; Fetaurus, 153 ; Gymnobelideus, 154 ; 
Dromicia, 154 ; Distoechurus, 155 ; Acrohates, 155 ; Subfamily 
Phascolarotinae, 155 ; Phascolarctus, 156. Extinct Phal- 
ASGEROIDS, 157 ; Thylacoleo, 157. Family Mackopodid.*, 
168 ; Subfamily Hypsiprymnodontinffi, 162 ; Hypsiprymnodon, 
162 ; Triclis, 162 ; Subfamily Potoroinse, 162 ; Fotorous, 163 ; 
Bettongia, 163 ; Caloprymnus, 164 ; uSSpypirymnus, 164 ; Sub- 
family Macropodinfe, 164 ; Lagostrophus, 165 ; Hendrolagus, 
165 ; Dorcopsis, 166 ; Lagorchestes, 166 ; Onychogale, 166 ; 
Fetrogale, 167 ; Macropiis, 167 ; Extinct genera, 170. Extinct 
Families, 171 ; Diprotodon, 171 ; Nototherium, 171. 

CHAPTER VII 

The Subclass Eutheeia and the Order Edentata . . 173 

General characters and classification of Eutheria, 173. 
Order Edentata . . . . . .176 

Family BEADYPODiDiE, 179 ; Bradypus, 181 ; Cholospus, 
182 ; Nothropus, 183. Family Megathepjid.e, 183 ; Mega- 
thermm, 185 ; Scelidotherium and Mylodon, 188 ; Fromega- 
theritom,189. i^amZj/ Myrmecophagid*, 190; Myrmecophaga, 
190; TaTiiatidua, 192 ; Cycloturus, 193. Family Dasyeooijim, 
194 ; ^'Mft/amiZj/ Chlamydophorinae, 196 ; Chlamydophorus, 196 ; 
Subfamily Dasypodinie, 197 ; Dasypus, 197 ; Xenurus, 198 ; 
Friodon, 198 ; Tolypeutes, 199 ; Subfamily Tatusiinse, 200 ; 
Tatusia, 200 ; Extinct genera, 201. Family Glyptodontid.e, 
202. Family Manid.*:, 204 ; Manis, 204 ; Palceomanis, 208. 
Family Orycteeopodid^, 208 ; Oryderopus, 208. Biblio- 
graphy, 211. 

CHAPTEE VIII 

The Orders Sirenia and Cbtacea . . .212 

Order Sirenia . . . . . .212 

Family Manatid^, 215 ; Manatus, 215. Family Hali- 
COEID^, 220 ; Salicore, 220. Family Rhytinid.*;, 221 ; 
Rhytina, 221. Extinct Sirenians, 222 ; Haliiherium, 222 ; 
Other forms, 223. Bibliography, 224. 

Order Cetacea . . . . . . '2,25 

Suborder Mystacoceti ...... 234 

■ Family BAL.ENlDiE, 234 ; Balajiia, 236 ; Neobalmna, 241 ; 

Ehachianectes, 241 ; Megaptera, 241 ; Balmnoptera, 242 ; Extinct 

genera, 245. 



CONTENTS 



Suborder Abch^boceti ...... 

Family Zeuglodontid.e, 246 ; Zeuglodon, 246. 
Suborder Odontoceti ...... 

Family PHTSETBRiDiE, 247 ; Subfamily Physeterinse, 248 ; 
Fhyseter, 248 ; Oogia, 250 ; Extinct physeteroids, 251 ; Sub- 
family ZiphiinEe, 251 ; Hyperoodon, 252 ; Ziphius, 254 ; Meso- 
plodon, 254 ; Berardius, 256 ; Choneziphius, 257. Family 
SQUALODONTiD.a;, 257; Squalodon,,1'i1 . i^'amiZy Platanistid^, 
257 ; Platanista, 258 ; Inia, 259 ; Pontoporia, 259 ; Fossil forms, 
259. i^amiZj/ Delphinid^, 260 ; Monodon,2%0; Delphinapterus, 
262 ; Plioccena, 263 ; Cephalorhynchus, 266 ; Orcella, 267 ; Orca, 
267 ; Pseudorca, 268 ; Globicephalus, 268 ; Grampus, 270 ; 
Feresia, 270 ; Lagenorhynchus, 270 ; Delphinus, 271 ; Tursiops, 
271 ; Prodelphinus, 271 ; /Sfeno, 271 ; Sotalia, 272. Biblio- 
graphy, 272. 



FAQS 

246 



247 



CHAPTER IX 

The Oeder Unqulata . . . . . 

Ungulata Vera ...... 

Suborder Artiodactyla . . . . . 

SuiNA, 278. Family Hipp0P0TAMiD.si, 278 ; Hippopotamus, 
278. Family SuiD^, 281 ; Sus, 281 ; Babirusa, 287 ; Phaco- 
chcerus, 288. Family Diootylid.*;, 289 ; Dicotyles, 289 ; 
Hyotlierium, etc., 291. Extinct Teansitional Artiodaottles, 
292 ; ChceropotaraidEe, 292 ; Antliracotheriidse, 292 ; Meryco- 
potamus, 293 ; Cotylopidse, 293 ; Anoplotheriidse, 293 ; Caeno- 
tlieriids6, 294 ; Dichodontidfe, 294. Tylopoda, 295. Family 
CAMELiD.as, 296 ; Camelus, 296 ; Auchenia, 298 ; Extinct 
Cameloids, 303. Teagulina, 305. Family Traguhd.e, 305 
Tragulus, 305 ; Dorealherium, 306 ; Extinct Traguloids, 306, 
Peooea, 307 ; Antlers, 308 ; Horns, 310 ; Teeth, 310 ; Stomach, 
312. Family Ceevid.«, 313 ; Subfamily Moschina;, 314 
Moschus, 314 ; Subfamily Cervinse, 316 ; Plesiometacarpalia, 
316 ; Cermilus, 316 ; Elaphodus, 318 ; Cervus, 319 ; Telemeta 
carpalia, 323 ; Eangifer, 324 ; Alces, 326 ; Cervalces, 327 
Oapreolus, 327 ; Eydropotes, 328 ; Oariacus, 329 ; Pttdua, 330 
Extinct genera, 330. Family GIEAFFID.E, 330 ; Giraffa, 331 
Allied extinct types, 332. Family ANTlLOOAPEiDiE, 333 
Antilocapra, 333. Family BoviDiE, 334 ; Alcelaphus, 334 
Oonnochcetes, 336 ; Oephalophus, 338 ; Tetraceros, 338 ; Neo 
tragus, 338 ; Nanotragus, 339 ; Pelea, 339 ; Oobus, 339 ; Oervi 
capra, 340 ; Antilope, 340 ; ^pyceros, 341 ; Saiga, 341 
Pantholops, 341 ; Gatella, 341 ; Hippotragus, 343 ; Oryx, 343 
Addax, 345 ; Boselaphus, 345 ; Tragelaphus, 346 ; StrepsiceroS: 
347 ; Oreas, 348 ; Extinct types, 348 ; Pupicapra, 349 ; Nemo- 
rhcedus, 350 ; Haploeeros, 351 ; Budorcas, 351 ; Capra, 352 
Ovis, 354 ; Ovibos, 357 ; Bos, 360. 



273 

275 
275 



CONTENTS xiii 

PAGE 

Suborder Perissodactyla . . . . .368 

Family TAPmiDiB, 370 ; Tapirus, 370 ; Palxotapirus, 373. 
Family Lophiodontid^, 373. Family Pal^othekiidj;, 375. 
Family Equid^, 376 ; Protohippus, 380 ; Hipparion, 380 ; 
Sguus, 381. Family Rhinoceeotid.S}, 402 ; Hhinoceros, 402 ; 
Extinct types, 411. Families Lambbothekiid^, Chalioo- 
THEKUDa;, and TiTANOTHBUliDiB, 412. Family Maorau- 
OHENiiD^, 414. Family Peoteeothekut)^, 414. 

SUBUNGULATA ....... 414 

Suborder Htbacoidea . . . . . .415 

Family HYP.ACiDiE, 415 ; Hyrax, 417 ; Dendrohyrax, 418. 
Svhorder Probosoidea . . . " . . .418 

Family ELEPHANTiD.ffi, 423 ; Elephas, 424 ; Mastodon, 431. 
Family DiNOTHEKiiDiE, 435 ; Dinotherium, 435. 

Suborder Amblypoda ...... 436 

Uintatherium, 436 ; Coryphodon, 437. 
Suborder Gondylarihra . . . . .438 

Suborder Toxodontia ...... 439 

Nesodmi, 439 ; Toxodon, 439 ; Typotlwrium, 440. 
Group TiLLODONTIA . . . . . .441 

Bibliography of Ungulates ..... 442 



CHAPTER X 

The Order Rodentia . . . . . 

Suborder Simplicidentata .... 

Section Sciitromobpha, 448. Family ANOMALtiMDiE, 449 
Anomalurus, 449. Family SoiUKli).*, 450 ; Sciurus, 450 
Rhifhroseiwrus, 452 ; Xerus, 452 ; Tamias, 452 ; Pteromys and 
Sciuropterus, 453 ; Fupetaurus, 454 ; Extinct genera, 454 
Arclomys, 454 ; Cynomys, 455 ; Spermophilus, 456 ; Extinct 
genera, 457. Family HAPLODONTiDiE, 457 ; Haplodon, 457. 
Family CASTORiDiB, 457 ; Castor, 457. Section MyomoephA; 
459. Family My'0XID.e, 459 ; Myoxus, 459 ; Eliomys, 459 
GrapMurus, 459 ; Clamglis, 460 ; Muscardinus, 460. Family 
LoPHiOMYiDiE, 460 ; Lophiomys, 460. Family MtrEiD^, 461 
Hydromys, 461 ; Xeromys, 461 ; Platacanthomys, 462 ; Gerbilhis. 
462 ; Pachyuromys, 462 ; Mystromys, 462 ; Otomys and Dasymys, 
462 ; Malacomys, 462 ; Phloeomys, 462 ; Dendromys, 463 
Cricetus, 463 ; Molochilus, 464 ; Sigmodon, 464 ; Rhithrodon 
and Oclietodon, 464 ; Neotoma, 464 ; Sypogeomys, 465 ; Nesomys, 
465 ; Brachylarsomys, 465 ; Sallomys, 465 ; Fliiirics, 465 ; 
Phenacomys, 466 ; Arvicola, 466 ; Synaptomys, 467 ; Myodes, 
467 ; Cuniculus, 470 ; Fiber, 470 ; Neofiber, 472 ; Ellobius, 



443 
448 



CONTENTS 



472 ; Siphneus, 472 ; Deomys, 473 ; Mus, 473 ; Nesocia, 475 ; 
Gohmda, 476 ; Uromys, 476 ; Ohiruroinys, 476 ; Sapalotis, 
476 ; Mastacomys, 476 ; Acanthomys, 476 ; Uchinothrix, ill ; 
Typhlomys, 477 ; Cricetomys and Saccostomus, 477 ; Pithechirus, 
477. Family Spalaoid^, 477 ; Spalax, 477 ; Jthizomys, 477 ; 
Bathyergus, 478 ; Gem-yclius and Myosoalops, 478 ; Hetero- 
cephalus, 478. Family GEOMYiDa;, 478 ; Geomys, 478 ; 
Thomomys, 478 ; Dipiodomys, 479 ; Perognathus and Heteromys, 
479. Family DiPODlDiE, 479 ; Sminthus, 479 ; Zapus, 480 ; 
Dipus, 480 ; Alactaga, 480 ; Platycercoinys, 480 ; Pedetes, 480. 
Section Htstrioomokpha, 480. Family Octodontid.e, 480. 
Oteiiodactylus, 481 ; Pectinator, 481 ; Octodon, 481 ; Sdbrocoma, 
482 ; Schizodon, 482 ; Ctenomys, 482 ; Spalacopus, 482 ; 
Petromys, 482 ; MyopotamAis, 482 ; Capromys, 482 ; Aulacodus, 
483 ; Plagiodon, 483 ; Lcmcheres and Echinomys, 483 ; Mesomys, 
483 ; Dactylomys, 483 ; Oercomys, 483 ; Carterodon, 484 ; 
Fossil forms, 484. Family TheeidomyiDjE, 484. Family 
HTSTEiciDiE, 484 ; Erethizon, 484 ; Syiietheres, 485 ; CJudomys, 
486 ; Hystrix, 486 ; Atlierura, 487 ; Trichys, 487. Family 
CmNCHiLLiDiE, 487 ; OhincMlla, 487 ; Lagidium and Lagosto- 
mus, 488 ; Extinct genera, 488. Family Castokoidid^, 488 ; 
Oastoroides, 488. Family Dasypeootid^, 488 ; Dasyprocta, 
488 ; Ocelogenys, 489. Family DiNOMYiDiE, 489 ; Dinomys, 489. 
Family Caviid^, 489 ; Cai-jVt, 489 ; Dolichotis, 490 ; Hydro- 
chaerus, 490 ; Extinct genera, 491. 

Suborder Ddplicidentata . . . . .491 

Family Lagomyid^e, 491 ; Lagomys, 491. Family Lepo- 
ElDiE, 492 ; Zepus, 492. 

CHAPTER XI 

The Order Garnivora ..... 496 

Suborder Garnivora Vei^a . . . . .497 

Section .Sltjeoidea, 501. Family Felid^, 502 ; i^eKs, 
502 ; Oyncelurus, 523 ; Extinct genera, 523. Family Yivee- 
ElDiE, 525 ; Oryptoproeta, 525 ; Viverra, 526 ; Fossa, 527 ; 
Geneita, 528 ; Prionodon, 530 ; Poiaiia, 531 ; Paradoxurus, 
532 ; Ardogale, 533 ; Ecmigale, 533 ; Arctictis, 534 ; Kandinia, 
634 ; Cynogale, 534 ; Herpestes, 535 ; Selogale, 537 ; Bdeogale, 
537 ; Cynictis, 537 ; Rhinogale, 537 ; Crossarchus, 537 ; Surkata, 
538 ; Galidietis, Galidea, and Hemigalidea, 538 ; Eupleres, 
538 ; Extinct genera, 539. Family PEOTELBiDiE, 539 ; Proteles, 
539. Family HY.a;NiD.«, 540 ; ffycena, 540. Section Cynoidea, 
544. Family CANiDiE, 544 ; Camjs, 546 ; Lycaon, 553 ; Icticyon, 
553; Otej/o», 554; Extinct genera, 555. /SecitoiiAKOTOiDEA, 556. 
Family UESID.B, 557 ; DVms, 557 ; 3le!ursus, 560 ; JEluropus, 
560 ; Extinct genera, 561. Family PROOYONiDa;, 562 ; 
^lurus, 562 ; Procyon, 564 ; Bassaris, 566 ; Bassaricyon, 566 ; 
Nasua, 566 ; Cercoleptes, 567. Family Musteud^, 567 ; 



CONTENTS 



Lutra, 567 ; Extinct Otters, 570 ; Latax, 570 ; MepMtis, 572 ; 
Conepatus, 574 ; Arctonyx, 574 ; Mydaus, 575 ; Meles, 575 
Taxidea, 576 ; Mellivora, 576 ; Helictis, 51?i ; lotonyx, 579 ; 
Galictis, 579 ; Mustela, 579 ; Extinct Mustelines, 590 ; Fmdlo- 
gaU, 590 ; Zyneodon, 590 ; G^jiZo, 591. 

Suborder Pinnipedia . . . . . .592 

Family OTAiiiiD.E, 593 ; Otaria, 593. Family Tmche- 
oniDM, 596 ; Trichechus, 597. Family Phooid*, 600 ; 
Haliduzrus, 601 ; Phoca, 601 ; Moiiachus, 604 ; Ogmurhinus, 
605 ; Lobodon, 605 ; Pcecilophoca, 605 ; Ommatoplioca, 605 ; 
Cystoptiora, 605 ; Macrorhinus, 606 ; Extinct seals, 606 

Suborder Creodonta ..... 606 

Hyaenodontidse, 608 ; Proviverridse, 608 ; Aretocyonidfe and 
Mesonychidse, 609. 

CHAPTEE XII 

The Order Insectitora . . .610 

Suborder Dermoptera . . . . . .614 

Family Galeopithboid.j:, 614 ; Galeopithecus, 614- 
SuSorder Insectivora Vera . . . . .616 

Family Tupawdm, 617 ; Tupaia, 617 ; Ptilocercxis, 618 ; Ex- 
tinct genera, 618. Family MACEOSOELiDiDa:, 618 ; Macroscel- 
ides, 618 ; Mhynchoeyon, 618. Family EKiNAOEiD.aB, 619 ; 
Gymnura, 619 ; Frinaceus, 620 ; Extinct genera, 621 ; Family 
SORlOlDiE, 621 ; Sorex, 622 ; Soriculus, 624 ; Kotiosorex, 624 
Blarina, 624 ; Crossopus, 625 ; Ifyosorex, 625 ; Crocidura, 626 
Diplomesodmi, 626 ; Anurosorex, 626 ; Chimarrogale, 626 ; JVecto- 
gale, 627 ; Fossil SoricidfE, 627. Family TALPiDy-E, 628 
Myogale, 628 ; Urotrichus, 629 ; JJropsilus, 629 ; Scalops, 630 
Scapanus, 630 ; Condylura, 630 ; Scaptonyx, 630 ; Talpa, 630 
Extinct genera, 634. Family Adapisorioid«, 634. Family 
PoTAMOQALiDiB, 634 ; Potamogale, 635 ; Geogale, 635. Family 
SoLENODONTiDiB, 635 ; Solenodon, 636 ; Gcntetes, 637 ; Hemi- 
centetes, 637 ; Fricuhis, 638 ; Microgale, 638 ; Oryzm-ictes, 638 ; 
Ohrysochloris, 639. Extinct types, 640. Bibliography, 640. 

CHAPTEE Xm 

The Order Chiroptera ..... 641 

Suborder Megachiroptera . . . .650 

Family PTEROPODiDiE, 650 ; Epomopliorus, 650 ; Pteropus, 
651 ; Xantharpyia, 652 ; Boneia, 653 ; Cynopterus, 653 ; 
Harpyia, 653 ; Gephalotes, 653 ; Pteralopex, 654 ; Notopteris, 
654 ; Eonycteris, 654 ; Carp>ooiycleris and Melonyeteris, 654 ; 
Nesonycteris, 655 ; Callinycteris, 655 ; Trygenyderis, 655. 



xvi CONTENTS 

PAGE 

Suborder Microchiroptera . ... 655 

Section Vespbktilionina, 655. Family Rhinolophid.e, 
656 ; Mhinolophus, 656 ; Hipposiderus, 657 ; Anthops, 657 ; 
Khinonycteris and Tricenops, 658 ; Calops, 658 ; Megaderma, 
658. Family VESPEETiLiONiDiB, 660 ; Plecotus, 660 ; Synotus, 
661 ; Otonycteris, 661 ; Nyctophilus, 661 ; Antrosous, 661 ; 
Vesperugo, 661 ; Ohalinolobus, 662 ; SeotopMlus, 662 ; Nyctice- 
jus, 663 ; Atalapha, 663 ; Sarpyiocephalus, 663 ; Vespertilio, 
663 ; Cerivoula, 664 ; Natalus, 664 ; Miniopterus, 664 ; Thyrop- 
tera, 665 ; Myxopoda, 665 ; Fossil Vespertilionidse, 665. 
Section Emballonukina, 666. Family EMBALLON"criiiD.E, 666 ; 
Furipterus and A7norphochilus,666; Uinballonura, 667; Coleura, 
667 ; Rhynchonycteris, 667 ; Saccopteryx, 667 ; Taphozous, 667 ; 
Diclidurus, 668 ; Noctilio, 668 ; Rhinopoma, 669 ; Chiromsles, 
669 ; Molossus, 670 ; Nyctinomus, 670 ; Mystacops, 671. Family 
PHYLLOSTOMATID.B, 672 ; GMlonycteris, 672 ; Mormops, 672 ; 
Lonchorhina, Otopterus, and Dolichophyllum, 673 ; Vampyrus, 
etc. , 673 ; Desmodus, 677 ; Diphylla, 678. 

CHAPTER XIV 

The Order Primates . > . . . . .680 

Suborder Lbmdroidea ...... 682 

Family Lemukid^e, 683 ; Indris, 684 ; PropUhecus, 684 ; 
Avahis, 686 ; Lemur, 687 ; Sapalemiar, 689 ; Lepidolonur, 
689 ; ChirogaUus, 689 ; Galago, 690 ; Nycticehus, 691 ; Loris, 
692 ; Pcrodicticus, 693. Family TABSllBiE, 694 ; Tarsius, 
694. Family Chiromyid.b, 694 ; Chiromys, 695. Extinct 
Lemueoids, 696. 

Suborder Ajjthropoidba . . . ... 699 

Family HAPALiDiE, 709 ; Eapale, 710 ; Midas, 710. Family 
Cebid.«, 711 ; Mycetes, 711 ; Pitheda, 712 ; Uacaria, 712 ; 
Oallithrix, 713 ; Chrysothrix, 714 ; Nyctipithecus, 714 ; Ateles, 
715 ; Eriodes, 715 ; Lagothrix, 716 ; (7e6Ms, 717. Family 
CEROOPlTHEOiDiE, 718 ; Cynocephalus, 719 ; TheropiOiecus, 111 ; 
Cynopithecus, 722 ; Macacus, 722 ; Cercocetms, 723 ; Cerco- 
pithecus, 724 ; Nasalis, 725 ; Semnopithecus, 726 ; Oolobus, 
727 ; Extinct genera, 727. Family Simiidje, 728 ; Hylolates, 
728 ; Simia, 731 ; Gorilla, 734 ; Anthropopithecus, 736. Family 
HoMiNiDiB, 739 ; Homo, 740. Classification of the varieties of 
Man, 743. 



AlSr INTEODUCTIOK 

TO 

THE STUDY OF MAMMALS 

LIVING AND EXTINCT 
CHAPTEE I 

INTRODUCTORY REMARKS 

Mammalia (French, Mammifhres; German, Sdugethiere) is tie name 
invented by Linneeus (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 Whales. 

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 vertebrated 
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 Palaeozoic 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 
Ichthyopsida (fishes and amphibians), and agree with the Sauropsida 
(reptiles and birds) in the possession during their development of 
an amnion and allantois, and in never having external branchiae 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 pau- 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 intra-uterine life between the 
circulatory systems of the parent and the foetus, 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 mammse, 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, they 
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 Buffalos, 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 we find the Llamas serving the same ofiice. 
In Lapland and other parts of the northern regions the Eeindeer 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 we have only to mention, among animals kept 
in a domestic condition, Swine, 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, while the Laps make use of the milk of 
the Eeindeer. The Eodents, as represented by Hares and Eabbits, 
occupy a minor position as furnishers of food. 

In relation to clothing, the Ungulates are likewise of paramount 
importance, as exemplified by the wool of the Sheep, which is so 
valuable on account of its peculiar property of felting. Furs, 
however, are mostly yielded by mammals of other orders, among 
which the Fur-seals are perhaps the most important at the present 
day. Many other Carnivores yield valuable furs, among which may 
be mentioned Bears, Foxes, Eacoons, Skunks, Minks, Otters, and 
Ermines. Of less importance are certain Eodents, such as the 
Squirrels, Eabbits, Hares, etc., while the hair of the Beaver was 
formerly much sought after for the manufacture of hats. Eeturning 
to the Ungulates, we 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 which 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 likewise 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, while 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 two 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 extensively 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 
Ehinoceros 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 a 
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. 



CHAPTEE II 

GENEEAL 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 (Choloepus) 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 Eodents 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, stiflfer, 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 stiffish hairs, called cilia or eyelashes ; and in most 
mammals specially modified hairs, constituting the vibrissce 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 {Ghrysochloris), the Desmans or Water Moles {Myogale), 
and Potamogale 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 (Brachyurus) has its whole face of 



TEGUMENTARY 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 {Dididurus 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 Eatels, Gluttons, ^lurus, 
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 birown 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 we 
may have black Leopards and Jaguars, black Wolves, and black 
Rabbits. 

The opposite to melanism, and of more frequent occurrence, is 



10 GENERAL ANATOMICAL CHARACTERS 

albinism — a condition in whicii 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 
congealed 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 Hght, is 
probably sufficient to account for this. Several races of true 
albinos, as White Ferrets, Rabbits, Eats, and Mice, have, however, 
been established under the protection of man, and in them this ab- 
normal condition is propagated from generation to generation. 

Partiar 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 wUd 
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 



Lion accords well with the prevailing tint of its native desert ; and 
any one who has seen an Elephant or Buffalo in the deep 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.'- 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 oiF 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 
Manidce 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 Rodents 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 
^ GaltoTis South Africa, p. ]87. 



12 GENERAL ANATOMICAL CHARACTERS 

EquidcB, 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 Rhinoceros 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, Ornithorhynchus, Proechidna, and Echidna. 

Odour - secreting Glands. — Besides the universally distributed 
sebaceous glands connected with 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 G-oat, the gland on the humeral 
membrane of Bats of the genus Saccopteri/x, 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, but 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. ■■■ 

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 efiicient 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 

■^ L. F. E. Rousseau, Aiiatomie comparie du Syslhne dentaire chez V Homme ei 
chez lesprincipaux Animaux, 2d ed., 1839 ; F. Guvier, Des Dents des Mammifires 
consideries comme caractires zoologiques, 1822-25 ; R. Owen, Odontography, 
1840-45 ; C. G. Giebel, Odontographie, 1855 ; C. S. Tomes, Manual of Dental 
Anatomy, Human and Comparative, 3d ed., 1889. 



14 GENERAL ANATOMICAL CHARACTERS 

gums 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. ^ 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.^ 

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 

^ The lower incisors of some species of Shrews are, however, said to become 
ankylosed to the jaw in adult age. 

^ The teeth of the extinct Dinosaurian reptile Triceratops 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 eiiamel 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 lacunae 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 



1 6 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 biilk 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 Nasmyth'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 with 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, but 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 of 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 mags 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 



GENERAL ANATOMICAL CHARACTERS 



having at its extremity a minute perforation, through which the 
vessels and nerves requii-ed to maintain the vitality of the tooth enter 

the pulja- cavity, which is 



r 



very different from the 
Avidely ojjen cavity at 
the Imse of the grooving 
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 "rootedteeth." 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 coverina; 
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 l^eing only 
in consecjuence of absorption 
and retrocession of the sui-- 
rounding alveolar margins. 
If, as often happens, their 
surface wears away in mas- 
tication, it is never renewed. 
The open cavity at the base 
of the imperfectly developed 
tooth (Fig. 1, II.) causes it 
to resemble the persistent 
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 




Fig. 1.— Diagrammatic Sections of ^'ariou.s forms of 
Teeth. I. Incisor or tusk of Elephant, with pulp- 
cavity persistently open at base. II. Human incisor 
during development, with root imperfectly formed, 
and pulp-cavity widely open at base. III. Completely 
formed human incisor, with pulp-cavity contracted to 
a small aperture at the end of the root. IV. Human 
molar, with broad crown and two roots. V. Molar of 
the Ox, with the enamel covering the crown deeply 
folded, and the depressions filled up witli cement. The 
surface is worn by use ; otherwise the enamel coating 
would be continuous at the top of the ridges. In all 
the figures the enamel is blaclv, tlie pulp white, the 
dentine represented by horizontal lines, and tlie cement 
by dots. 



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, with 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 difi'erent 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. 

SiKcession. — 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 



20 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 de hit, 
German milchzahne) 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. 

When 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 



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 diflGiculties 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, 

^ 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 PhyHology, vol. iii. p. 262, 
1869 ; and "Notes on the First or Milk Dentition of the Mammalia," in the 
Trans. Odontological Society of Great Britain, 1871. See also an important 
memoir by Oldfield Thomas on the "Homologies and Succession of the teeth 
in the Dasyuridffi," 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 tbe 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 suflB.cient 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, iitting 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 




Fig. 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- 



DENTAL 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 
closely 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 1 1 above and 1 1 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 premaxilla 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 appears 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. 

With regard to the lower teeth the difiiculties 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 premaxUla, 
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 Gotylops, an extinct Ungulate from North America) 
the tooth that would thus be determined as the first premolar has 
the form of a canine ; but it should not be forgotten that, as in all 
such cases, deiinitions 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. 

Dental formulce. — 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 1 4-4 1 3-3 11-11 

incisors = — ^, canines = — =-, premolars - — -, molars ^ — r = — — ry ; 

— 1 — 1 4 — 4 o — oii — li 

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 T. i' r> ™ f = TT ; total 44. 

The individual teeth of each group are always enumerated from 
before backwards, and by such a formula as the following — 

il, i 2, i S, c, p 1, p 2, p S, p 4, m 1, m 2, m 3 
■i 1, i 2, i 3, c, ^ 1, ^ 2, ^ 3, ^ 4, m 1, m 2, m 3 

or more briefly — 

. 1, 2, 3 1_ 1, 2, 3, 4 1, 2, 3 

* 1, 2, 3' '^ 1' -^ 1, 2, 3, 4' ™ 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 ^ 
will mean the first upper molar, in the first lower molar, and so on. 
The use of such signs saves much time and space in description.^ 

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 

■• By many wi-iters the letters indicating the different kinds of teeth are 
printed in capitals, as I, 0, P, and M; while very frequently the symbol Fm is 
employed in place of ^. 



26 



GENERAL ANATOMICAL CHARACTERS 



would 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 



Z.\ Z.2 ^-3 



'p.'r 



^^■' 771.2, 




difVa.s 







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 f, 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 Palceotherium, 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 aU 
called molars in the milk-dentition, although as a general rule, in 



DENTAL SYSTEM 27 

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 Eodents, 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 
Zeuglodon 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,i 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 

12 3 4 5 

of particular teeth. Thus the hypothetical formula i ' ^ g' ^ g > 

'"I'P I 2' 3' 4 ' ™ 1 2 S 4 5 ' ^^ *^® ^°^® °^ *^^ ^^^^ lower incisor, 
and of the second premolars (which we know to be those which 
disappear in the Marsupials) and the fifth molars, will give 
• 1, 2, 3, 4, 5 1 1, 0, 3, 4 1, 2, 3, 4 .-l t 1 f +i, 

' 1, 2, 3; 4; ' 'i' ^toTti' ""r^zTi' °' *^^ ^°™''^'' °^ ^^^ 
Opossum {Didelphys), usually written i 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 ^ ^' g' ^ q , c -^ 

^ 1' 2' 3' 4 ' ™ r^"l^' °^ *^® formula of a typical Eutherian, like the 

^ According to Mr. G. E. Dobson there are four upper incisors in some of 
the Soricidce. 



28 GENERAL ANATOMICAL CHARACTERS 

Pig, whicli we generally write as if, c \, ^-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 Avide 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 ofi" 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 ofi" 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 weU-being 
of the animal in procuring its sustenance, and preserving its Kfe 
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 {Ohiromys) 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 which the crown of each 
tooth carried three cusps, and hence termed the trittiiercular 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, r). It is further probable that this 
tritubercular type was itself derived from a type of dentition in 



DENTAL SYSTEM 



31 



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 Dromatherium. Starting then 




Pio. 4.— Molar teeth of Mesozoic Mammals (enlarged). Triooiiodont type— 1, Dromatherium : 
2, Microconodon; 3, Ampliilestes ; 4, PhascoMhermm ; 6, Triconodon. Tritubercular type— 6, V, 
SpalacotMrium : 10, Astkemdon. Tubercular sectorial type— S, ^mpJiifflfriim; 9,Peramus: Il- 
ls, AmUotherium ; 14 (?) Amblotherium. pr, Protocone ; hy, hypocone ; pa, paraoone ; 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 JDroma- 
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 



i, e) having one inner and two outer cusps, while the reverse 
condition obtains in those of the lower jaw (Fig. 4, r). 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 ChrysocMoris ; 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 



.rue 






' Fig. 5. — Diagram of two upper and two lower left 
quadritulDercular molars in mutual apposition. The cusps 
and ridges of the upper molars in double lines, and those 
of the lower in hlack lines. The lower molars are looked 
at from helow, 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 Osbom.) 



THE SKELETON 33 



ml, fV). Finally, in the bunodont series, the addition of a postero- 
internal cusp (Fig. 5, hy\ 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 Molaes. 

Antero-internal cusp =protocoiie ='pr. 

Postero „ or 6th cusp = hypocone = hy. 

Antero-external cusp =paracone =pct. 

Postero ,, „ =metaoone =me. 

Anterior intermediate cusp = protoconule = wl. 

Posterior „ „ =metaconule =pl. 



Lower Molars. 




Antero-external cusp = protooonid 


=prd. 


Postero „ „ =liypoconid 


= hyd. 


Antero-internal or 5th. cusp =paraoonid 


=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 lacunas, 
connected together by delicate channels or canaliculi, which radiate 
in all directions from the sides of the lacunae. 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.^ 

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 
within the substance of some of the viscera. Such are the os arrdis 
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. 

^ See for the principal modifications of the skeleton of the class, the larce 
and beautifully illustrated OsUograpMe of De Blainville, 1835-54 ■ the section 
devoted to the subject in Bronn's Klasscn wnd Ordnwigen des Thier-Reichs, by 
Giebel, 1874-79 ; and An Introduction to the Osteology of the Mammalia, by 
W. H. Flower, 3d ed., 1885. 



THE SKELETON 



35 



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 oi'gans 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 IP 




Fig. C— Longitudinal and vertical section of the sk\ill of a Dog (Cauls famillaris), with 
mandible andhyoid arch, an, Anterior narial aperture ; MT, niaxillo-turhinal hone ; ET, ethmo- 
turbinal ; Na, nasal ; ME, ossified portion of the raesethmoid ; CE, cribriform plate of the 
ethmo-turbinal : Fr, frontal ; Fa, parietal ; IP, interparietal ; SO, supraoccipital ; ExO, ex- 
occipital ; BO, basioccipital ; Per, periotic ; BS, basispheuoid ; Ft, pterygoid ; AS, ali- 
sphenoid ; OS, orbitosphenoid ; PS, presphenoid ; PI, palatine ; VO, vomer ; Mx, maxilla ; 
PMx, premaxilla ; s?i, stylohyal ; eh, epihyal ; ch, ceratohyal ; bli, Ijasiliyal ; Ih, thyrohyal ; 
.S-. symphysis of mandible; cp, coronoid process; cd, condyle; a, angle; irf, 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.i 

vertebrfe, 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. 



36 GENERAL ANATOMICAL CHARACTERS 

occipital segment consists of the basioccipital, exoccipital, and 
supraoccipital bones ; the middle segment of the basisphenoid, ali- 
sphenoid, 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 
who have attempted to trace their serial homologies vsath 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 fossae, 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 squamosal (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 premaxillae (Figs. 6, 7, PMx), which carry the 
incisors ; behind them are the maxillae, in which all the remaining 
upper teeth are implanted. Both the premaxill» and maxillse 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 




between the prcmaxilla and maxilla of either side. Behind the nasals 
and maxiliai, the anterior part of the brain-case is formed by the 
large paircil frontals (Figs. G, 7, Fr), behind which are the parietals, 
which may be of still 
larger size, and form 
the greater i)art of 
the brain -case. A 

median interparietal Si!'^'i''''''( ^ 'ivii/}-^'^^ \ I ^- C^-si>X nir 

ossification (Fig. 0, 
//') may divide the 
}:)ariotals jiosteriorly, 
and is itself articn- 
lated with the snpra- 
occipital, to the lat- 
eral borilers of which 
the parietals are also 
joined. The squam- 

1 IX^' 1 C \ f ^^'^'' ^■^^'*^'-'' ^'i^'"' "' skull of Capo .Tiniipilig Hare (Pfdctca 

0Sal(tlg. I , oq) lOrms nqler). \i. rM.i; rioinaxilla ; Mx, maxilla; Ma, jugal or 

the lateral wall of mahir; t'r, IVoiilal ; L, laclirymal ; J'li, parietal; Na, nasal; 

the hinder part of •^:/. «a"a.ansal ; 7',, ty.upa,™ ; &., oxocdpital ; .«, alisphen. 

, , . *'"^ : f-''^! orbitospliL'iinul ; iVr, luasluRi liuUa. 

the bram-case, and 

articnlates snpcriorly 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 whei'e it gives oil' 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, Mil), which articulates jiostcriorly with the zygomatic process 
of the squamosal, and anteriorly with the maxilla. The jngal (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- 
poi'tant to obscrA'o th;it the zygomatic or temporal arch is a 
squamoso-maxilla.ry 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 atKnity. 
The relative ])osition 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 jieriotic 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 ])etrosal, and a j)ostero- 
external or mastoid portion (Fig. 8), which ajipcars on the outer wall 
of the brain-case. The tympanic is produced horizontally outwards 
to form the external auditory meatus or tube of the ear, while 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 
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 the Ma m- 
onalia already men- 
tioned. Attention 
may, however, be 
particularly di- 
rected to the so- 
called alisphenoid 
canal, the position 
of which is sho-\^Ti 
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. S. — 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 ; 
0, foramen ovale ; a, posterior, and a', anterior aperture of ali- 
sphenoid canal ; P, paroccipital process of exoccipital ; m, mastoid 
process of periotic ; am, external auditory meatus ; g, glenoid for- 
amen, below which is the glenoid cavity for the condyle of the man- 
dible. (Flower, Proc. Zool. Soc, 1869, p. 26.) 



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 ja^vs 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 
fiUed 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 aU 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. 

Vertebrrd, Column. — The rertehral column consists of a series of 
distinct bones called vertebrae, arranged in close connection with 
each other along the dorsal side of the neck and trunk, and in the 
median Une.^ 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 skuU. 
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 vertebras, with some 
exceptions, remain through life quite distinct from each other, 
though closely connected by means of fibrous stmctiu-es which 
allow of a certain, but limited, amoimt of motion between them. 
The exceptions are the following: — (1) near the posterior part 

^ For the sake of mufonnitT, in all the foUowing descriptions of the rertehral 
column, the long a-ris of the body is supposed to be in the horizontal position. 



40 



GENERAL ANATOMICAL CHARACTERS 



of the trunk, in nearly all mammals which possess completely 
developed hinder limbs, two or more vertebrae 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 
supi^ression 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- 





J)Z 



Fig. 9. — Anterior surface of Human 
thoracic vertebra (fourth), c, Body or 
centrum ; nc, neural canal ; jj, pedicle, 
and I, lamina of the arch ; t, transverse 
process ; az^ anterior zygapoplij'sis. 



Fig. 10.— Side view of the first lum- 
bar vertebra of a Dog (Cajiis familiaris). 
s, Spinous process ; az, anterior zygapo 
physis ; pz, posterior zygapophysis ; m, 
metapophysis ; a, anapopliysis ; 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 vertebrte. Its elasticity provides 
for the vertebrte always returning to their normal relation to each 
other and to the column generally, when they have been disturbed 
therefrom by muscular action. A process (p) arises on each side 
from the dorsal surface of the body. These processes, meetin" 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 "vvith synovial joints, placed one on 
each side, called "zygapophyses " (ii~., 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 
is), 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 
{t), of which there may be two, an upper and a lower, in which case 
the former lis called, in the language of Owen (to whom we are 
indebted for the terminology of the parts of vertebra in common 
use), " diapophysis," and the latter " parapophysis." Other processes 
less constantly present are called respectively " metapophyses " (w) 
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 
vertebrae of one are apt to blend into 
those of the next region, either normally 
or as peculiarities of individual skeletons. 

Cervical Vertehrce. — The cervical region 
constitutes the most anterior portion of ^'^^^^^^^p'~^(iz 

the column, or that which joins the 
cranium. The vertebrae 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, r) ■ or, ^J^\^^;~f'"lZ''^^,TTlot 
as it is sometimes described, they have j, spinous process ; a.-, anterior 
two transverse processes, superior and zygapophysis ; .>, vertebrarterial 

. p ' I'l , ,,!• 1. ' L- canal: ^, transverse process ; i', its 

inferior, which meet at their extremities inferior lameiia. 

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), whicli, being considered 
serially homologous with the ribs of the thoracic vertebrae (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 {Gholce,pus hoffmanni), 
which both have but six, and the Three-toed Sloth {Bradypiis 
tridaotylus), 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 VertebrcB. — 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 Vertehrce. — 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 12 dorsal and 7 lumbar vertebrae, or 13 
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. 1 7, 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 Perissodactyla. The highest and quite exceptional 
numbers are in the Two-toed Sloth {Gholmpus) 27, and the Hyrax 
30. The prevailing number of rib-bearing vertebrae is 12 or 13, 
any variation being generally in excess of these numbers. 

Sacral Vertebrce. — 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 vertebra 
between the lumbar and caudal regions which are ankylosed 
together to form a single bone. It happens, however, that the 
number of such vertebrse varies in different individuals of the 
same or nearly allied species, especially as age advances, when a 
certain number of the tail vertebrae generallj'^ become incorporated 
with the true sacrum. Other suggested tests — as those vertebrae 
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 equally 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 vertebrae in the following pages. The Cetacea, having no iliac 
bones, have no part of the vertebral column modified into a 
sacrum. 

Caudal Vertebrce. — The caudal vertebrae 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 
vertebrae 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, 
sometimes chiefly or entirely either to one or the other. 




Fig. V2. — Anterior surface of fourth 
caudal vertetrse of Porpoise (Phoccpna com- 
munis), s, Spinous process ; m, nietapopliy- 
sis ; t, transverse process ; h, che^Ton bone. 



but 



44 



GENERAL ANATOMICAL CHARACTERS 



In some of the Anomodont Reptiles and Labyrinthodont 
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 the mesial line, on the 
inferior or ventral aspect of the thorax, and connected on each side 

with the vertebral column by a series 
of more or less ossified bars called 
" ribs." It is present in all mammals, 
but varies much in character in the 
different groups. It usually consists 
of a series of distinct segments placed 
one before the other, the anterior 
being called the presternum or " manu- 
brium sterni " of human anatomy, and 
the posterior the xiphisternum, or 
xiphoid or ensiform process, while the 
intermediate segments, whatever their 
number, constitute the mesosternum 
or " body." In the Whalebone AMiales 
the presternum alone is developed, and 
but a single pair of ribs is attached 
to it. 

llibs. — The ribs form a series of 
long, narrow, and more or less flattened 
bones, extending laterally from the 
sides of the vertebral cohmm, curving 
downwards towards the median line 
of the body below, and mostly joining 
the sides of the sternum. The posterior 
ribs, however, do not directly articulate 
with that bone, but are either attached by their extremities to 
the edges of each rib in front of them, and thus only indirectly 
join the sternum, or else they are quite free below, meetino- no iiart 
of the skeleton. These diff'erences have given rise to the diA'ision 
into " true " and " false " ribs (by no means good expressions), si'nii- 
fying those that join the sternum directly and those that do not • 
and of the latter, those that are free below are called " floatino- " 
ribs. The portion of each rib nearest the vertebral colunui ami 
that nearest the sternum differ in their characters, the latter bein" 
usually but imperfectly ossified, or remaining permanently cartila- 
ginous. These are called "costal cartilages," or when ossified 
"sternal ribs." 




Fig. 13. --Human sternum and 
sternal ribs, ps, Presternum ; tjw, 
mesosternum ; xs, xiphisternum ; c, 
point of attachment of cLavicle ; 1 to 
10, the cartilaginous sternal ribs. 



THE SKELETON 



45 



In the anterior part of the thorax the vertebral extremity of 
each rib is di-s-ided into two parts, " head " or " capitulum," 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 vertebrae, 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 vertebrte. 

The circumstance that in some of the Anomodont reptiles and 




Fig. 14.— Sterrium and strongly ossified sternal ribs 
of Great Armadillo {Prwdon gigas). ps, Presternum ; 
x-s, xiphistemum. 




Fig. 15.— Skeleton of Lion (^Fdis leo). cd, Caudal vertebrtB : cp, carpus ; cr, coracoid process 
of scapula ; cv, cervical vertebne ; d, dorsal vertebrae ; /&, fibula ; /m, femur ; ft, humerus ; il, 
ilium : isch, ischium ; I, lumbar vertebra ; m, metatarsus ; mc, metacarpus ; j)y patella ; p&, pubis ; 
ph, phalanges ; pv, pelvis ; r, radius ; s, sacral vertebrae ; sc, scapula; sfc, skull ; th, tibia ; ts, 
tarsus ; u, 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. 

Appmidicular 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-arm or antebrachium, and the hand or manus. 

Shoulder-girdle. — The shoulder ov pectoral girdlem 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 ; atid 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 Potamogale), in many Eodents 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 Camivora, Myrmecophaga, and 
some Eodents. Clavicles are altogether absent in most of the Ursidce. 
all the Pinnipedia, Manis among Edentates, the Cetacea, Sirenia 
Ungulates, and some Rodents. 



THE SKELETON 



47 



The Monotremes are peculiar in possessing a T-shaped 
interclavicle like that of many reptiles, lying upon the sternum, 
and articulating superiorly with the clavicles. 

Brachium 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 internal 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 walking 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 




Fia. 16.- 



spect of 



Outer 

the proximal extremity of the 
right ulna of a Bear {Ursus). 
fl, Anterior tubercle ; ol, 
olecranon ; ?), greater sigmoid 
cavity : c, lesser do. 



48 GEA'ERAL ANATOMICAL CHARACTERS 

its anterior surface, and tlic 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 ui3f)er articular extremity, and firmly ankylosed to the radius 
— stability of these parts being more essential than mobility. 

Manns. — The terminal segment of the anterior limb is the hand 
or manus. Its skeleton consists of three divisions : (1) the 
" carjDus," 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, irith their proximal ends articulating by almost immo"\-able 
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. 

Ca)-j)us. — To understand thoroughl}' 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 (Chcli/dra scqiaitina). The 
carpus consists of two principal rows of 
bones. The upper or proximal ro^v con- 
tains three bones, to which Gegenbam- 
has applied the terms rudiah' [r), inter- 
mcJitiin ((), and tilnare (u), the first being 
on the radial or preaxial side of the limb" 
The lower or distal row contains five 
bones, called carjxde 1, -2, 3, 4, and "i 
respectively, commencing on the radial 
side. Between these two rows, in the 
middle of the carpus, is a single bone 
the centrak (c). In this very s^-mmetrical 
carpus it will be observed that the nidialc 
supports on its distal side two bones, 
F.o. ir.-Dorsai surface of «,e «w?«^'; 1 ^^d 2 ; the ihtmncdium is in a 
light manus of a Water Tortoise line with the ccutralc and carpa]c 3 which 
(vhciydm serpentina). After Ge- together fomi a median axis of the Ivmrl 

i;enfiaur. U, Ulna ; E, radius : ii, ,., j.i ; i , "luni, 

ulnare ; i, intermedium ; r, radiale : '^^'lllle the illllare lias also two bonCS articu- 

c, centrale ; 1-5, tbc five bones of latiug with its distal end, VIZ. earn de 4 

tlie distal row of the carpus ; ml- ., ., ,^ r^ 17 ^ .^1^ .-.-C +1, . i r i , 

mr.. the five metacarpals. ^"^'^^ ^- Each of the Carpals of the distal 

row su}iports a metacarpal. 
1 The opinion lias recently been expressed by Baur that the bone ternie 1 
radiale in Fig. 17 is really a second eentrale, and that the radiale is represeutel 
by a minute bone generally known as the radial sesamoid. The mammalian 




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 = Naviculare. 
Intermedium = liuniiT =Semilunare, Lunatum. 

Ulnare = Cimeiform = Triquetrvm,, Pyramidale. 

Centrale = Central = Intermedium (Cuvier). 

Carpale 1 = T!ia,Tpe,zmia = Multangulum majus. 

Carpale 2 = Trapezoid = Multangulum minus. 

Carpale 3 = Magnum = Capitatum. 

„ -^ , , l = Unciform = Hamat^im, Uncinatum. 
Carpale 5 J 

The radial and ulnar sesamoids are regarded by Bardeleben '^ as 
the rudiments of a prepoUex 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 Pedetes coffer, 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 Aimt. 
Anzeiger, vol. iv. pp. 49-52, 1889.) 

* On the Prajpollex and Prehallux, 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 " unguligrade." 

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 Hmb 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 MarsupiaUa, 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 MarsupiaUa, 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, caUed " fabellse." 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 Pig. 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. 

r . \- \ = Astragalus! = Talus. 

Intermea/bum J ° 

Fihulare = Calcaneum = Os calcis. 

Centrals = Navicular = Scaphoideum. 

Tarsals 1 = Internal cuneiform = Entocuneiforme. 

Tarsals 2 = Middle cuneiform = Mesocuneiforme. 

Tarsals 3 = External cuneitorni = Ectocuneiforme. 

I = Cuboid. 



Tarsals 4 
Tarsals 5 



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 (») 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^), middle (c% and external (c^), articulated to the distal surface 
of the navicular, and the cuboid (ch), articulated with the calcaneum 
Of these the middle cuneiform is usually the smallest in animals 

' Cope and Baur consider that the astragalus corresponds only with the inter- 
medium, and that the tibiale may exist as a distinct element. 



THE DIGESTIVE SYSTEM 



53 



in which all five digits are 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 -^vith 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 
Eodentia ; 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 C njptoproda there 
ma]- be a second centrale, which usually 
coalesces vnth. 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 tiljial side, 
or hallux, resembles the pollex of the hand 
in always ha\'lng one segment less than 
the other digits. 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 Haliiherium. 




Fio. IS.— Bones of tlie right 
Human foot, T, Tarsus ; M, 
luetatarsus ; Pli, phalanges ; c, 
calcaneum ; a, astragalus ; c6, 
cuboid ; ■?!, navicular ; ci, inter- 
nal cuneiform ; c-, middle cunei- 
form ; c^, external cuneiform. The 
digits are indicated by Roman 
numerals, counting from the 
tibial t<;i the fibular side. 



IV. THE DIGESTIVE SYSTEM. 



General Conghleralions. — 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 aU 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 we might weU 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 aU 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 mce 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, omng 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 
drive 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 papillae, 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, 
common. Under the name of salivary glands are commonly 




Fig. 19. — Salivary Glands of the Genet. A, Right side of the head dissected ; ^, parotid 
gland ; d, Steno's duct ; sai, submaxillary gland, traversed by the jugular veins (jy) ; o, apertui-e 
of Steno's duct. If, Part of the head with the lip drawn up to show (s(.d) aperture of 
Steno's duct ; z,ql^ zygomatic gland ; o, aperture of do. ; 2, zygomatic arch. (Jlivart I'roc. 
Zool. Soc. 1S82, p. 604.) 

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 mouth, 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.gV), 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 diflferent 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 now 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, which " chew the cud," — it is swallowed, and carried along 
the CESophagus by the action of its muscular coats into the stomach. 
In the greater number of mammals this organ is a simple saccular 



SS 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 
walls 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 panci-eas of the Genet. Posterior or dorsal surface, tt', CEsophagus ; 
s, pancreas ; pc?, pancreatic duct ; M, biliary duct from the liver. (From Mivart, i*roc. ZooL 
Soc. 18S2, p. 306.) 

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 IManatee and the curious African 
Rodent Lophmni/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 undergoino- 
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 ccecum 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- 
lationship between the size and complexity 
of this organ and that of the stomach. 
Where the latter is simple the caecum is 
generally the largest, and vice versd. Both the 
caecum and colon are often sacculated, a dis- 
position caused by the arrangement of the 
longitudinal bands of muscular tissue in their 
walls ; 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 which 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 




Fig. 21. — Diagrammatic 
plan of the general arrange- 
ment of the alimentary canal 
in a typical Mammal, o, 
Oisophagus ; st, stomach ; p, 
pylorus ; s, s, small intestine 
(abbreviated) ; c, ciecum ; i, I, 
large intestine or colon, end- 
ing in r, the rectum. 



6o 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 right 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 
difiicult 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 Doo', 
for instance, do not correspond with 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 



6i 



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, m) 
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 which 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- 




Fio. 22.— Diagrammatic plan of the inferior surface of a multiloted liver of a Mammal. 
The posterior or attached border is uppermost, v., Umbilical vein of the foetus, represented by 
the round ligament in the adult, lying in the umbilical fissure ; dv, the ductus venosus ; i>c, 
the inferior vena cava ; p, the vena portse entering the transverse fissure ; llf, the left lateral 
flssuie ; rlf, the right lateral fissure ; c/, the cystic fissure ; U, the left lateral lobe ; ic, the left 
central lobe ; re, the right central lobe ; ri, the right lateral lobe ; s, the Spigelian lobe ; c, the 
caudate lobe ; (/, 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 seg-ment 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 (?<), the organ has that 
tripartite or trefoil-like 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 (r/ and II). 



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 (c/). The 
portal fissure (^), 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 (vc) 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 diflference 
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 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. -Deo. 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, with 
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 -^-j^-g- of 
an inch, which is exceptionally large, and only exceeded by the 
Elephant (2-7^5)1 ^ii*i ^7 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 xt^tt-''^ 

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 {diordoB 
tendinice) and arising from projections of the muscular walls of 
the ventricular cavity {musculi papillares). 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 (as cwdis) 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, Froc. Zool. Soc, 1862, p. 91. 



64 GENERAL ANATOMICAL CHARACTERS 



each guM'ded by threo somiluna.r valves. Tlio aorla, is single, and 
arches over tho loft bronchiaJ tube. After siii)pl,ying the tissues i>f 
tlie lioiu't itself with blood by moans of tho coronary arlorios, it 
gives off largo vessels ("carotid") to tho head and ("brachial") to the 
anterior extrciuitios. Tho mode in which these vessels arise from 
the aorta varies niuch in difl'erent mammals, and tho study of their 
disposition affords some guide to elassilication. In nearly all cases 
the right brachial and carotid ha\e a common origin (called the 
"innominate artery" in anthropotomy). The other two vessels 
may come off from this, as is the rule in Ungidates, tho connnon 
trunk constituting tho "anterior aorta" of veterinary anatomy ; or 
they may be detached in various degrees, both arising so|)aratoly 
from the aorta, as in Man, or the left carotid from tho innominate 
a,nd 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. Tho aorta, after giving olV 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 sporma,tic vessels, gives oil' 
in the lumbar region a large branch (iliac) to each of tho hinder 
extremities, which also supplies the pelvic viscera, and is contiinicd 
onwards in the middle line, greatly diminished in size, along the 
under surface of tho tail as tho caudal artery. In certain mammals, 
arterial ploxusos, called rdia miraliilia, formed by the brealiing u}> 
of the vessel into an immense number of small trunks, wliicli may 
run in a straight course parallel to ono another (as in the limbs of 
Sloths and Slow Lemurs), or form a, closely packed networlc, as in 
the intracranial plexuses of liuminants, or a sponge-liko mass of 
convoluted vessels, as in tho intercostals of Cetaceans, ai'o 
peculiarities of tho vascular system the meaning of which is 
not in all cases clearly understood. In the Colacoa they are ob- 
viously receptacles for civntahiing a largo qua.ntity of oxygenaled 
blood available during the prolonged inmiersion, with consc(nu>nt 
absence of respiration, to which those animals a.i-e subject. 

The vessels returning the blood to the heart from tho head and 
upper extremities usually unite, as in Man, to form the single iviki 
niva superior or precaval vein, but in some Insoctivor(\s, Chirontora. 
and Rodents, in the Elephant, and all Marsupials and Monotremes 
the two superior ca,val veins enter the right anride widiout unitiu"-' 
as in birds. In Seals and some other diving mammals there is a 
large venous sinus or dilata,tion of the inferior vena, cava innnediately 
below tho (liM,pln'a,gm. In the Cetacoa the iiur]ioae of this is suiJiilieil 
by the immense abdominal venous iilexuses. As a rule tho veins 
of mammals ai'c furnished with valves, but these are said to bo 
altogether wanting in the Oetacea, and in the superior and infoi'ior 
cava, subclavian and iliac veins, tho veins of tho liver (both portal 



ABSORBENT SYSTEM . 



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 laminse 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 gastro-epiploic, and the pancreatic veins. 
The kidney is supplied solely by arterial blood, and its veins empty 
their contents only into the inferior cava. 

Lymphatic Vessels. — 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 receptaculum chyli. This duct, 
which is of irregular 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 braehio-cephaUc 
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. Xo 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 " 



66 GENERAL ANATOMICAL CHARACTERS 

on one side, into which the splenic artery, a branch of the cceliac 
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 fuU growth is 
attained. 

Nostrils. — Mammals breathe occasionally through the mouth, 
but usually, and in many cases exclusively, through the nostrils or 
nares. 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 6; 

the ■vralls of the long tubular proboscis, this apparatus is entirelv 
■wanting. 

Troj:h:a. — The narial passages have the organ of smell situated 
in their upper part, and communicate posteriorly irith the 
pharynx, and through the glottis -with the "trachea"' or ■windpipe. 
a tube by ■which the air is conveyed to and from the lungs. The 
permanent patency of the trachea diu-ing 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 
t^wo bronchi, one of which enters, and, di^viding dichotomouslv. 
ramifies through each lung. In some of the Cetacea and 
Artiodactyla a third bronchus is given off from the lo^wer 
part of the trachea, above its bifurcation, and enters the right 
lung. 

Liifnx. — The upper end of the trachea is modified into the 
organ of voice or "lai-ynx," 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 ttibe, into vibra- 
tion. The larynx is composed of several eartUages, such as the 
"thyroid," the "cricoid," and the '" arytenoid "' which are moved 
ujxin one another by muscles, and siispended 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 voliune 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 commtmi- 
cates ■with the pharynx, from the entry of particles of food diu-ing 
deglutition. The form of the larynx and development of the vocal 
cords present many variations in dilferent members of the class, 
the greatest modification from the ordinary type being met ■with in 
the Cetacea. where the arytenoid cartilages and epiglottis are imited 
in a tubular manner, so as to project into the nasal pissage, and, 
being grasped by the muscular posterior margin of the palate, pro- 
vide a direct channel of communication from the lungs to the 
external svu^face. An approach to this condition is met with in the 
Hippopotamus and some other Ungidates ; it is indeed so general 
as an abnormality, that Howes suggests that an intemarial epi- 
glottis may have been a primitive feature common throughout the 
class. Xearly all mammals have a voice, although sometimes it is 
only exercised at seasons of sexual excitement. Some ^larsupials 
and Edentates appeju- to be quite mute. In no mammal is there 
an inferior larynx, or '• syrinx," as in birds. 

Diaphragm. — The thoracic ca^^ity of mammals differs from that 
of the Sauropsida in being completely separated from the abdomen 
by a muscular pirtition, 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. 

Imngs. — 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 eifected 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 suflEicien,t 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 EquidcB 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 {Gystophora and 
Macrorhinus) large pouches, which the animal can inflate with air 
and which are not developed in the young animal or the female' 



URINARY 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 sacculi laryngis, 
found in a rudimentary state in Man, and attaining an enormous 
development, so as to reach to the shoulders and axillae, 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 SYSTEM 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 lower 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 Eodent 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 



NERVOUS SYSTEM 



71 



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- 



great degree to the size of 



the 



ation of the species, but also 
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 
{sf) 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 vertebrae, and gives off the compound double-rooted 
nerves of the trunk and the extremities, corresponding in number 
to the vertebra, 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-raarginai sulcus ; c, notch represent- 
ing crucial sulcus of other forms ; d, depression ou 
superior lateral gyrus of hemisphere : hg, hippo- 
campal gyrus ; i, inferior lateral gj'rus of hemi- 
sphere ; m, middle lateral gyrus of do. ; s, superior 
lateral gyrus of do. ; os, supraorbital sulcus of do. ; 
sf, sylvian Assure of do. ; ol, 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. 616.) 



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 papillae, 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 papillae. 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 papillae scattered on 
the dorsal surface of the tongue. The organ of smell is present in 
all mammals except the Toothed AVhales. 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 mth 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 Platanida or 
Freshwater Dolphin of the rivers of India. In aU 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 



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 piu'pose 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 performed by winking the true 
eyelids. Except in Cetacea the surface of the eye is kept moist by 
the secretion o^ 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 fibro-cartilaginous 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. 



Vn. 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 diifers 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 

^ The modifications of tliese bones are fully described by A. Doran, "Morpbo- 
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, Rodentia, Insectivora, 
and Cbiroptera, 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 virith muscular walls, in vsrhich the 
ovum undergoes the changes by which it is developed into the 
foetus, 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. 

Seamdary 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 besi^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 Bovidce. 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 inelano- 
pogon), 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 Ornithwhynchus 
and Echidna, the use of which is at present unknovra. 

Placenta. — The development of the mammalian ovum, and the 
changes which the various tissues and organs of the body undero-o 
in the process of growth, 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 
ovum, 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 viteUine duct. 
The mesoblastic tissue of the walls of the allantois soon becomes 
vascular ; its arteries are supplied with foetal blood by the two 
^lypogastric branches of the iliacs, or main divisions of the abdominal 
aorta, and the blood is returned by venous trunks uniting to 
form the single 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 



78 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,^ 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,^ while Dr. Selenka,^ and 
Professor H. F. Osborn* have contributed important evidence as to the 
structure and relations of the fcetal 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 walls 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, which 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 formino- 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. Sd. Philadelphia, 1881, p. 468. 

' " Studien uebor Entwiclcelungeschichtc dcr Thierc," T^t. i^ "Wiesbaden 1886 
* Journal of Morphology, \o\. i. ^. Z1^ {1?>?>1). 



REPRODUCTIVE ORGANS 79 

birds, rather than from the uterine walls by means of the allantoic 
vessels, as in the higher mammals. The latter vessels, in fact, play- 
even 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 Eodentia, 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 



8o 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) deoiduate. In the former the foetal villi are received into corre- 
sponding depressions of the maternal surface, from which at the 
period of parturition they 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, althouo-h 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. Eecent observations by 
Sir W. Turner on the placentation of the Dugong show that the 



REPRODUCTIVE ORGANS 8i 

Sirenia 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 Euminants 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 lasf>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 disooidal 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 fcetal 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.-' 

^ For a full exposition of the present state of knowledge on this subject, see 
the various memoirs of Sir WOliam Turner, also F. M. Balfour's Treatise on 
Comparative Embryology, vol. ii. (1881), andJ. 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 afiinities. In arranging the classes of vertebrates in a linear 
series it is customary to place them in the following order — Pisces, 
Amphibia, Eeptilia, 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 ^ 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 down to the Amphibia. 
In addition to the characters derived from the conformation of the 
pelvis upon which the argument was primarily based, the following 
i:easons 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 ardh 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 '^ 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 E. 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,^ 
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 Eeptilian. 
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 Keptiles, 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). 

2 "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 Eeptiles 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 we 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 difi'erent 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 afiinities. 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 difi'erent 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 SSI PICA TION 8 5 



but the subject will be more fully developed in treating separately 
of eacb 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) Diddphia, (3) MoTwdelphia — 
the first being equivalent to the order Monotremata, the second 
to the Marsupialia, and the third including all the remaining 
members of the class. Although actual palseontological 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 
Prototheria, 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 Peototheria, 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 EcMdnidce. 

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 marked 
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 MoNODELPHiA. 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 
"Encyclopaedia." 

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 we 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 
which, 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 Archaeoceti. There 
is nothing known at present to connect the Cetacea vnth 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 Pachydermata, 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 vidth apparent relation- 
ships with the Ungulates, through the Elephant on the one hand 
and the extinct Typotherium 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 Pinnipedia) 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 



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 ; 
biit 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 (Hapale) to 
Man. Certain breaks in the series, however, enable us to divide 
it into five distinct families : — Hapalidce or Marmosets ; Ceiidce 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, Simla, Gwilla, and 
Anthrqpopithecus, the true Man -like Apes; and, lastly, Hominidce, 
containing the genus Homo alone. 

Subclass I. Peototheeia. 
Order i. Monotebmata — Monotremes. 

Fam. 1. OrnithorhyncMdce — Duck-bill. 
2. Echidnidce — Spiny Anteater. 

Group. MULTITUBERCULATA.1 

Fam. 1. Flagiaulacidse — Plagiaulax. 

2. Polymastodontidse — Polymastodon. 

3. Tritylodontidae — Tritylodon. 

Subclass II. Metatheeia. 
Order ii. Maesupialia — Marsupials. 

Suborder 1 . Polyprotodontia — Polyprotodonts. 

1 The names of the gi'oups containing only extinct forms are printed in heavier 
type than those which contain species still existing. 



CLASSIFICA TION 



Fam. 1. Dromatlieriids — Dromatheriuni. 

2. Amphitheriidee — Amphitherium, etc. 

3. Spalacotheriidae — Spakcotherium. 

4. Tritylodontidse — Tritylodon. 

5. Bidelphyidm — Opossums. 

6. DasyuridcB — Thylacine and Dasyures. 

7. Peramelidce — Bandicoots. 

Suborder 2. Dipkotodontia — Diprotodonts. 
Fam. 8. Phascolomyidx — Wombats. 
9. Phalangerid(B — Phalangers. 

10. Diprotodontidae — Diprotodon. 

11. Nototheriidse — Notothere. 

1 2. Macropodidm — Kangaroos. 

Subclass III. EUTHEEIA. 

Order iii. Edentata — -Edentates. 
Fam. 1. Bradypodidce — Sloths. 

2. Megatheriidae — Ground Sloths. 

3. MyrmecophagidcB — Anteaters. 

4. Dasypodidce — Armadillos. 

5. Glyptodontidse — Glyptodonts. 
C. Manidw — Pangolins. 

7. Orycteropodidm — Aard-varks. 

Order iv. Sieenia — Sirenians. 

Fam. 1. ManatidcB — Manatees. 

2. Rhytinidse — Rhytina. 

3. Halicoridce — ^Dugongs. 

4. Halitheriidae — Halithere. 

Order v. Cetacea — Cetaceans. 

Suborder 1. Mystacoceti — Baleen Whales. 
Fam. 1. Balcenidce — Greenland Whale, etc. 

Suborder 2. AKCHJEOCETI. 

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. Artiodacttla — Artiodactyles. 
Section A. Sdina — Pig-like Artiodactyles. 
Fam. 1. Hippopotamidce — Hippopotamus. 
2. Suidce — Pigs and Peccaries. 



^< 



90 ORIGIN AND CLASSIFICATION 

3. Choeropotamidse — Choeropotamus. 

4. Anthracotheriidae — Anthraoothere. 

5. Merycopotamidse — Merycopotamus. 

6. Cotylopidse — Oreodonts. 

7. Anoplotheriidee — Anoplothere. 

8. DichodontidaB — Dichodon. 

Section B. Teagulina — Clievrotains. 

9. Tragulidce — Chevro tains. 

Section C. Tylopoda — Camels. 

10. Camelidce — Camels and Llamas. 

1 1 . Poebrotheriidae — Poebrotherium. 

Section D. Pecora — True Ruminants. 

1 2. CervidcB — Deer. 

1 3. GiraffidcB — Giraffe. 

14. Antihcapridcs — Prong-buck. 

15. Bovidce — Slieep, Cattle, etc. 

Suborder 2. Peeissodactyla — Perissodactyles. 

Fam. 16. Tapiridce — Tapirs. 

1 7. Lophiodontidas — Lophiodonts. 

1 8. Palaeotheriidae — Palaeotheres. 

19. Equidce — Horses. 

20. Rhinocerotidce — Rhinoceroses. 

21. Lambdotheriidas — Palaosyops. 
2 2. Chalicotheriidae — Chalicothere. 

23. Titanotheriidae — Titanothere. 

24. Macraucheniidae — Maorauchenia. 

Suborder 3. TOXODONTIA— Toxodonts. 
Fam. 25. Toxodontidae — Toxodon. 
26. Typotheriidae — Typothere. 

Suborder 4. CONDYLAETHRA. 

Fam. 27. Periptychidae — Periptycbus. 

28. Phenacodontidae — Phenacodus. 

29. Meniscotheriidse — Meniscothere. 

Suborder 5. Hyracoidea — Hyraces. 
Fam. 30. Hyracidm — Hyrax. 

Suborder 6. AMBLYPODA. 

Fam. 31. Pantolambdidae — Pantolambda. 

32. Coryphodontidae — Coryphodon. 

33. Uintatheriidae — Uintatbere. 

Suborder 7. Pbobosoidea — Proboscideans. 
Fam. 34. Dinotheriidas — Dinothere. 
35. Elephantidce — Elephants. 



CLA SSIFICA TION g i 



Group. TILLODONTIA— Tillodonts. 

Fam. Anchippodontidae — Anchippodus. 
Calamodontidse — Calamodon. 

Order vii. Eodentia — Eodents. 
Suborder 1. Simplicidentata. 

Fam. 1. Anomaluridm — Auomalurus. 

2. Sciuridce — Squirrels and Marmots. 

3. Haplodontidce — Haplodon. 

4. Ischyromyidse — Ischyromys. 

5. Castoridee — Beavers. 

6. Myoxidce — Dormice. 

7. Lophiomyidre — Lophiomys. 

8. MuridcB — Rats, Mice, and Voles. 

9. SpalacidcE — Mole-rats. 

10. Geomyidce — Pouched Rats. 

11. Dipodidm — Jerboas. 

1 2. Theridom3ridse — Tberidomys. 

13. Octodcntidos — Spiny Mice. 

14. Castoroididae — Castoroides. 

15. HystricidcB — Porcupines. 

1 6. GhincMUidce — Chincliillas. 

17. Dinomyidce — Dinomys. 

18. C'aviidce — Cavies. 

1 9. I)asxjproctid(E — Agouties. 
Suborder 2. Ddplicidbntata. 

Fam. 20. Lagomyidm — Picas. 

21. Leporidm — Hares and Rabbits. 

Order viii. Carnivora — Carnivores. 

Suborder 1. Cabnivora Vera — Fissipedes. 
Fam. 1. Felidce — Cats. 

2. HycenidcB — Hyaenas. 

3. Proteleidce — Eartb-wolf. 

4. Viverridce — Civets and Ichneumons. 

5. Canidcs — Wolves and Foxes. 

6. Ursidce — Bears. 

7. Mustelidm — Weasels and Otters. 

8. Procyonidce — Racoons and Cat-bear. 
Suborder 2. Pinnipedia — Pinnipedes. 

Fam. 9. Otariidm — Eared Seals. 

1 0. Trichechidoe — Walrus. 

11. Phocidoe — Seals. 
Suborder 3. CREODONTA— Creodonts. 

Fam. 12. Hysenodontidse — Hyaenodon, 

1 3. Proviverridse — Proviverra. 

1 4. Arctocyonidse — Arctooyon. 

15. Mesonychidse — Mesonyx. 



92 ORIGIN AND CLASSIFICATION 

Order ix. Insectivora — Insectivores. 
Suborder 1. Insectivora Vera. 
Fam. 1. Tnpaiidm — Tupaias. 

2. Macroscelididce — Elephant-Shrews. 

3. Erinaceidoe — Hedgehogs. 

4. Soricidce — Shrews. 

5. Talpidw — Moles. 

6. PotamogalidcB — Potamogale. 

7. Soletwdontidce — Solenodon. 

8. Gentetidce — Centetes. 

9. GhrysochloridcB — Golden Moles. 

Suborder 2. Dbrmopiera. 

Fam. 10. Galeopithecidce — Galeopithecus. 

Order x. Chiroptera — Bats. 

Suborder 1. Megachiropteha — Frugivorous Bats. 

Fam. 1. Pteropodidce — Flying Foxes. 
Suborder 2. Microchiroptera — Insectivorous Bats. 
Fam. 2. Vespertilionidw — Common Bats. 

3. Nycteridce — Nycteris. 

4. Rhinolophidm — Leaf-nosed Bats. 

5. Emhallonuridos — Emballonura. 

6. FhyllostomatidcE — Vampyres. 

Order xi. Primates. 

Suborder 1. Lemuroidea — Lemuroids. 
Fam. 1. Hyopsodontidse — Hyopsodus. 

2. ChiromyidcE — Aye-Aye. 

3. Tarsiidoe — Tarsier. 

4. Lemuridce — Lemurs. 

Suborder 2. Anthropoidea — Anthropoids. 
Fam. 5. Hapalidoi — Marmosets. 

6. OeUdx — American Monkeys. 

7. GercopithecidcB — 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. 



CHAPTEE IV 

GEOGRAPHICAL AND GEOLOGICAL DISTEIBUTION" 
I. GEOGRAPHICAL DISTRIBUTION.! 

In considering the present distribution of mammals over the 
globe, we 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 Ehinoceros 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, which 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 

' 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 lAfe, 1881 ; also A. Heilprin, The Geographical and Geological 
Distrilmtion 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 Eeindeer 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-like JElv,roj)%s, 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 vnth 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 Thylacinus, re- 
presented only by the so-called Tasmanian Wolf -or Thylacine is 
now entirely restricted to Tasmania ; but the family Dasyuridce, to 
which that genus belongs, ranges all over Australia, while the order 
Marsupialia, which includes the Dasyuridce, 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 markedly 
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 sufftciently 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, which 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, whicli 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, which 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 ofl^ 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 diflferent 
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 World genera as Horses and 
Ehinoceroses. 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 oroups 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 PalEearctic 



ZOOLOGICAL REGIONS— PAL^ARCTIC 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 Baluchistan, the Malay peninsula, southern 
China, Sumatra, Java, Borneo, and the Philippines. Fourthly, 
the Australasian region, which 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 Palsearctic and Nearctic regions have a large number 
of common types, more especially among the mammals, and Dr. A. 
Heilprin ^ 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 
Palsearctic, 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 Palsearctic, 
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. 

Palceardk Region. — The Palsearctic 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 



98 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 Palaearctic, although we meet with one Goat {Cajyra) in the 
Nilgherries of Southern India, and a Sheep {Ovis) in the Nearctic 
region. The Musk Ox (Ovibos) is characteristic of the Palaearctic 
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 (Rupicapra), the Saiga of 
Tartary, and the Chiru (Pantholops) 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 Palaearctic. 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 Palaearctic, 
although one species enters JSTorthern India, while the Desmans 
{Myogale) of the Pyrenees and Southern Eussia are unknown 
beyond the limits of this region. The Water-shrew {Nectogale) is 
likewise a peculiar eastern Palaearctic type. Among the Rodents, 
the Picas or Tailless Hares {Lagomys) and the Dormice {Myoxua) 
are essentially Palaearctic 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 
Eats are represented by the typical genus Mus and other types, 
and Hares (Lepus) and one species of Squirrel (Sciurus) are common. 
The Carnivora include two species of Bears (Utaus), "Wolves and 
Foxes (Canis), a Lynx and a few species of Cats (Felis), as well as 
numerous weasels (Mustela), and some other types. 

Ethiopian Regim. — 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 wide 
extent of grassy plains (veltd), as well as vast tracts of equatorial 
forests of great density. Perhaps the most striking featiu-e 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 (Giraffa) 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 {Phacochcerus) and the 
Eiver-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 {Gazella) 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 Cervidce, which are so characteristic 
of the Palsearctic and Oriental regions. The Chevrotains or 
Tragulidm are, however, represented by Dorcatherium?- 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 Rhinoceroses, 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 Hysenas, 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 Simiidce, which, with the exception of 
the Orangs of Borneo, are the only existing large man-like Apes, 
and the group of Dog-faced Baboons (Gyiwcepludus) in the Cercopithe- 
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 
' Generally known as Hyomoschus, but first described as an extinct form 
under the above name. 



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 {Oryderopus), 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 were represented in India, and many 
of them also in Europe. 

Oriental Region.— Th^ 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 
Ehinoceroses, 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 Oarnatic, 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 Palaearctic and 
Ethiopian forms, vrith 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 IDeer and true Pigs. The Antelopes 
comprise the two peculiar genera Boselaphus (Nilghai) and the 
typical Antilope (Black-buck), each of which is represented by only 
a single species, while the Deer belong to the so-called Eusine 
group, which is markedly different from that to which the 
Palaearctic Eed Deer belongs. True Chevrotains (Tragulus) 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 



ORIEKTAL REGIOX loi 

only by a single species in the desert area of the Indian sob-region, 
TFhile the two species of Bhinoca'-x': difier from those of Airioa 
in being famished -with cauiaes and indsors. The Malajau 
Tapir is the onlr Old World species of its genns. The Indian 
Elepbant dififers, moreoTer, so martedlv from its African ally that 
some ■writeis regaoti the t«-o as types of distinct genera. The 
CamiTora indnde tiie lion, Leopard, Jackal, and Huntang-Leopard, 
which are common to Africa : but the Tiger is very characteristic 
of this resdon, althoush extendinff northwards into the Palaearctic, 
CSivete are abundant, comprising some peculiar genera, of which it 
wfll suffice to mention the w-ell known Paradeaaavs. "WolTes dosely 
allied to the PsJ»arctie spedes occur in Xorthern India, and there 
are also Foxes related to the typical species. The Dog-like animals 
which himt in packs, and are separated by some writers from Canis 
under the name of tV*», occur in the present and the Palfearctic 
region. The striped Hysena is the Indian representative of its genus- 
Katels are common to this and the Ethiopi;vn region, and constitute 
the genus JWdKtora. The most striking fearure in the CaxniTorous 
hxxDst, of Ihis r^on, as distinguished from the Ethiopian, is, howcTer, 
the presence of Bears, some of which bdong to the typical genus 
Ursus, while one species is usually generically separated under the 
name of J/p/wrsMS. Among the Bodents we may especially notice 
the abundance of the Mwridm and Sdmidtr. In the former &mily 
we hare numbers of true Mice (^-l/r/,-~\ and also the peculiar genus 
-Vdsof ja (Bandi)X>ot-£at\ while in the latter botii the true Squirrels 
(Smms) and the Mying-Squirrds {Ptenmufs) anain great dcTelop- 
ment. The genus (Pfenomje) is, indeed, mainly characteristic of this 
region, althon^ in Kashmir and Japan it enters the Plalsearctic. 
The B^ts are very numerous, being represented by all the families, 
with the exception of tiie PAWfosfomaAVto, or Yampyres, of South 
America. Among the Inseotivora the genera Tupaia and Galeo- 
pUkeeus (^Flying Lemur) are peculiar to this region, although not 
fotmd in India. Finally, in the Primates we ha^e the genera 
MamcMS and Simnepith'CfHs rery abimdantiy represented, although 
both also enter the PsiUearctic region ; but the Anthropoid types 
are confined to the south-eastern half of the region, and indnde the 
Orangs (Sirma) of Borneo, and the smaller long-armed Gibbons 
{Hylotiatts), which are abundant ia the Malay peninsula, both 
genera not beuag found beyond this region. The Lemurs are much 
less abundant than in the Ethiopian region, but they indnde the 
peculiar Tarsier of Sumatra, Borneo, and Cdebes (Atistro-Malayan 
T^on\ 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 fomily. The Edentates, so poorly represented in the 
Old World, include only P:uigolins {MmisX which, as we have 
alreadv seen, also occur in the Ethiopian region. 



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 
we 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 {Muridm), 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 Opossums {Didelphyidce), 
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 Pefaurus. 

Nearctic 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 Palsearctic 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 (Cerms) 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 we have, in addition 
to the forms already mentioned, one species of the Palsearctic o-enus 
Ovis, namely the Big-horn, and the Prong-buck {Antilocap-a), which 
is quite peculiar. There are, however, no Perissodactyla. The 
Racoons and Coatis (Procyonidce) constitute a family represented out 
of the New World only by the aberrant Cat-Bear {Mlurv£) of Nipal. 
The characteristic American feline known 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, which 
alone would tell us what part of the globe we were visitin"-. The 



^'EOmOFICAL JiEGJO-V 103 

most distinctiTe are the Pouched Eats (^(?: ;.;:,•. i'tY and the Beaver-like 
rodents known as the ify'- ■! • ,'1 rkAr. True Eats and Mice \lius\ 
which are represented throughout the Old World, are totaily wanting' 
in the Xew, where they are replaced by the Tesper-mioe. which mar 
be included in the European genu; CnV -; -. although often sepirated 
as fffnvroTii!//. This feature alone would seem to justifT the dis- 
tinction of the XeAiorio from the Palwarctic region. The ^Jtisquash 
(Fil'fr) is a genus of Xearotio rodents unknown in the Old World. 
Among other characteristic genei-a we mar mention, in the Camivora, 
the Skunk (Mt])hms) and the American Badger [Taxidea). Primates 
are absent from the entire region. 

_V;.n' rf.-.i; i^tyiV-n. — ^The last of the six main regions is the 
Xeotropical, including Mexico. South America, and the West Indies. 
A very large esttent of this area is occupied bv forests, which are 
described as being denser and more luxuriant than those of anr 
orher part, of the globe. Alternating with these forest areas are 
the vast grassy plains known in different regions as llanos, sarannas. 
and pampas. The back -bone of the region is formed by the great 
chain of the Andes. 2\ext to the Attstralasian, this region is 
perhaps better characterised by its mammalian fatma than any of 
the others. Commencing with the ITngulares. 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 (Cdri'j.cu') unknown beyond the Xew World. The 
Peccaries (/'iV'. 'v'->'\. which are often made the type of a distinct 
fanuly. take the place of the Old World Pigs, while the Llamas and 
Alpacas (Auyiynia) are the substitutes for the Palwarctic Camels. 
The Carnivora include several Cats {F-sIl^X among which the Puma 
and the Jaguar are the most noticeable : and there are also Eacoons. 
Coatis, Foxes, and one species of Bear. Insectivora are totally 
wanting : but the Bats are characterised by the presence of the 
Tampyres {Phyliasfomaiidir). which are almost restricted to this 
region. The E'xients likewise include three families unknown 
elsewhere, namely the Chinchillas and Tiscacha [C/iiiichiUidir), the 
Agouties (Z^.^y, I :' ■■fiW'.T'. and the Caries (Cariid'j) ■. while a large 
number of the Odo'ioniidiT are Xeotropical. 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 
Ceiid'.T or Prehensile-tailed ^lonkeys. and the H:ytihd(e, 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. Perhaj», however, the mammals which may be 
considered as most characteristic of the Xeaictic region are the 
numerous Edentates, which form three families, mostly confined to 
it. These comprise the Brc vfpf'ii'.lx or S.cths. which solely 
inhabit the forest region : the JIi,rr7::a>j'h>.i<riAX or Anteaters ; and 



104 GEOGRAPHICAL DISTRIBUTION 

the Dasijpodidm 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 
Didelphys. 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 
(Fhyseter 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 Rorqual (Balcenoptera) 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 difiacult 
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 delphis) and the 
so-called D. bairdi of the North Pacific and I), forsteri of the 
Australian seas. The Pilot Whale (Globicephalus melas) and the 
Pseudorca 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 Eight Whales (Balcena) 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 Eight Whale as a sea 
of fire, through which he cannot pass." Hence all cetologists have 
assumed that the Eight Whale of the North Atlantic {B. hiscayensis), 
that of the South Seas {B. australis), and that of the North Pacific (B. 
japonica), 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 Eight 
Whale (Balcena 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 {Neohalcena 
marginata) has only been met with hitherto in the seas round 
Australia and New Zealand; and a large Ziphioid (Berardius 
arnouxi) 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 Plakvmta 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. iiidi was formerly separated from F. (jaitgdica ha^^e been 
shown by Anderson to be of no constant \'alue. Oirclla JhitiiinaUs 
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 Neoiiicris 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 Sireiiia, 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 (Ulanatus) 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 Dugong 
(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 pui-pose of 
breeding. The geographical range of the various species is generally 
more or less restricted, usually according to elimate, 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 leoninus), 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. 

HI. Paleozoic or Primary — 

1. Permian — Beds overlying the Coal. 

2. Carboniferous — Coal-measures, etc. 

3. Devonian — Old Red Sandstone. 

4. Silurian — Wenlook 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 



io8 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.i 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 Tlieriodesmus, 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 kno^vn by Professor Marsh, while another 
fertile source of these remains occurs in the Laramie beds of the 
Upper Cretaceous of the United States. ^ 

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 



n- 




t'S 



f *^ 



1 * 




Fig. 24.— Frontal and oral aspects of the cranium of Tritylodon longcrius ; from the 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. 

iluUituberculata. — The name Multituberculata has been proposed 
for the group exhibiting the type of dentition last mentioned, and 
is generally adopted, although the term AUotheria 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 ilammalia of the Mesozoic Forma- 
tions," Pakeontographical Society's PuUications, 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 shoidd especially consult the memoir by the latter 
writer on the "Structure and Affinities of the Jlesozoic Mammals," published in 
the Journal of the Philadelphia Academy (1888), vol. i.x. 



GEOLOGICAL DL^TRIBUTIOX 



lower ja-w (Fig. 25) ami of one larger incisor, and in some instances 
of one or two smaller ones in each premaxilla (Fig. -4). 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. '1-^), arc 
characterisetl by ha-\-ing 
longitudinal rows of 
tubeicles separated by 
one or more giooA'es ; 
there being either two 
or three of these rows 
in the upper molars of 
those forms in which 
these teeth are known, 
while there arc, at least 
usually, only two in 
those of the lower jaw. In other cases the premolars are of a 
secant tj'pe, with a highly convex cutting-edge, and usually either 
serrated or oliliquely grooved (Figs. l'.5, :2(i). From a certain 
resemblance between these secant premolars and those of some of 
the smaller Macniptididiv it was at one time considered that we had 
in these mammals representatives of Dipi'otodont ^Marsupials. The 
irreat dilt'erence in the structure of the molar teeth of these forms. 




Fii3. '1:k — The right viuiius of the iimiidible of I'lagiauJiu- 
hflif^i : from tlie rin-beck or S\\:ui;im', T\\ieo iiatx^ral size. 
(, hii'isor ; m, nioLir ; b, eoronoiil process ; c, condyle. tAI'tei 
Oweu.) 





Flo. 20. — The imperrect right ramus of tlie 
mandible of i7((j; /((((/((.(■ minor ; from Swanayr, 
Kniir times natural .size, j', Trenu^lar.s ; m, 
molars. (After Lyall.) 



Fio. 2T.-->7(c<ii[/«afAu,-; odUlhk-ii^i. Frag- 
ment of jaw with three tcelli (a, h, eV in 
matnx ; from the Slnneslicld Slate. Natu- 
ral size. C.\.Her Owen.) 



coupled with the circumstance that when the number of upper 
incisors is reduced lielow three it is the second in place of the first 
which becomes enlarged and opposed to tlie incisor of the lower 
jaw, seems to prevent the act'cptation of this view. .Alorcover in 
tlieir peculiar structure the molars seem, on the \\-liole, to make a 
nearer approximation to the teeth of Ornitlioi-ln/iicliiit! than to aiiv 
other known mammal ; and it has aceordingly been suo;i;osted tlia'r 
tlu^ Mnltitubercula.ta may really represent an order of rvototheria. 
Some support is afibrtled to this suggestion liy certain fragmentarv 
bones from the Cretaceous of the United States, which are regarded 



MESOZOIC MAMMALS 



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 aU the members of 
this group, and it will therefore suf&ce 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 ilesozoic 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 Bolodon, closely aUied to which is Allodon of the 
Upper Jurassic of the L'nited States. 

The first discovery of the remains of Mesozoic mammals was 
made in the Keuper or L'pper Trias of the Ehaetian 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. Subsequently Mr. C. ^loore discovered in a 
bone bed of Ehjetic (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 E. Owen to Pleininger's genus Microlestes, and 
described specifically as M. moorei. Under the name of Hypsi- 
prymnopsis rhceticus, Professor Boyd DawMns described a single tooth 
with two roots discovered in the Ehaetic Marlstone at Watchet in 
Somersetshire. Sir E. Owen referred the latter tooth to Jlicrolesfes, 
and if its describer is right in regarding it as a much worn premolar 
of the type of those of Plagiaulvx (Fig. 2-5) there would be evidence 
that Microlestes was closely aUied to the latter, from the molars 
of which those of Microlestes are scarcely distinguishable. 

Plagiaulax, of the Dorsetshire Purbeck (Figs. 24, 2-5), is at once 
distinguished from Tritylodon by its secant premolars, which, as already 
mentioned, recall those of some of the Jlacropodiche, although readily 



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 Eat-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 E. 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 (6) 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, i 

Allied types, such as Cknacodon, are also met with in the Upper 

^ 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. Oeol. Soc. vol. xiv. 1857 ; (2) R. Owen 
art. " Falsiontology," BncyclopiEdia Britannica, 8th ed., 1859; (3) H. Falconer 
"On the Disputed affinity of the Mammalian genus Plagiaulax," Quart. Journ. 
Geol. Soc. vol. xviii. 1862 ; (4) R. Owen, "Monograph of the Fossil Mammalia 
of the Mesozoic Formation," Palceontographical Society, 1871, 



MESOZOIC MAMMALS 113 

Jurassic of North America ; and the Plagiaulacidce also persisted 
into the lower part of the Eocene division of the Tertiary period ; 
Neoplagiaulax being a Tertiary form common to Europe and the 
United States, while Liotomus and Ptilodus are at present known 
only from the latter country. 

The present group is also represented in the upper Cretaceous 
of the United States by Selenacodon (Menisco'essus in part), Gimoliomys, 
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. 

Polyprotodont 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. 
31. 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 
(Triacanthodon), in which the formula of the lower teeth is i 3, c 1, 
p i, 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 

T , -^ . , . , ., -r, . Fig. 28. — Beversed view of the 

upper and lower jaw bemg alike. Pna- jeft ramus of the mandiwe of 

COdon, of the Jiu:assic of the United States, Triconodon mordax ; from the 

is probably inseparable from Triconodon. P"-^teek of swanage. Natural 

XI T-.T 7 7 ■ /TT rt^\ [• s^^^' (After Owen.) 

In the genus Phascolotherium (rig. 29) of 

the Lower Jurassic Stonesfield Slate, the lower teeth may be 

classified as » 4, c 1, ^ 3, m 4, the premolars and molars being 




114 



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 




Fig. 29. — Inner view of the right ramus of the mandible of Plicscolotherium l/ucldandi ; 
from the Stonesfield 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.) 

Phascohtherium is remarkable for the extremely low position of 
its articular condyle. In Amphilestes (Fig. 30) of the Stonesfield 
Slate the molars appear to be of the same general type as those 
of Phascohtherium, but are more numerous, although their exact 
number cannot be determined. A somewhat different type 
of lower molar is displayed by the genus Amhhiiherivm, of the 
Dorsetshire Purbeck, to which Amphitherium of the Stonesfield Slate 
was probablj^ 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 AmUotherium 
is i i, c I, p 4, m 
7-8. Numerous allied 
types, such as Achyro- 
don and Dryolesies 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 Siylacodon ha^-e been 
formed upon specimens showing the opposite side to that which 
is exposed in the types of Amblotheriuiii and Ampldthcrium. The 




\C 1 1 2 3 4 5 



Fig. 30.— Keveised mnei view of the left ramus of the 
mandible of Amphilestes hroderipi ; from the Stonesfield 
Slate. Twice natural size. The restoration of the anterior 
teeth is conjectural, and the condyle is placed too high. 
(After Owen.) 




TERTIARY MAAIMALS 115 

only parallel among existing forms to the excessive number of 
molar teeth found in these Mesozoic genera occurs in the Mar- 
supial genus Myrmecohius, 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 Myrmecohius 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 Spalacotherium was 
established, the upper jaws, 
described as Peralestes, being t, „-, „ ^ , tv , ,* , ti, 

' o FiQ. 31.— Part of the left ramus of the man 

apparently referable to the same dible, viewed from the outer side, of Spala- 

animal. Upper and lower teeth cotUHum trkuspicUns ; from the Purbecli of 

r .T ' (• , 1 ■ Swana^e. Twice natural size. (After Owen.) 

01 this form are represented m ° 

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 Chrysoddoris ; the 
number of lower teeth in Spalacothermm is, however, i 3, c 1, 
p + m 10, 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 



ii6 GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION 

period very intimately connected. A marked feature of ttese 
early Eutherians is the prevalency of trituberculism in the dentition, 
not less noteworthy being the frequent occurrence of pentadactyUsm 
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 
generalised 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 Ehinoceroses 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 Eheims 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 vndely distinguished from 
one another may be more conveniently noted when we come to the 
consideration of the families in question. 



CHAPTEE V 

THE SUBCLASS PEOTOTHEKIA 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 be 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 Echidnidoe, 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 -ndth 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 wall 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 vertebrae 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 
a^roximation to the Saiu-opsida (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 



ORNITHORHYNCHIDA: ng 

indicative of a very marked separation of neck from thorax, not 
seen in tte existing Sauropsida. The upper ends of the ribs 
are attached to the sides of .the bodies of the dorsal vertebrae 
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 
Keptiles, 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 walls 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 
fossae. 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 Ornithorhynchus, but 
this disappears when the animal becomes adult.) The stomach is 
sub-globular and simple ; the alimentary canal has no ileo-csecal valve, 
or marked distinction between large and small intestine, but has a 
small, slender vermiform caecum 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 ORNITHORHYNCHIDiE. 

Ornithorhynchus.'^ — Cerebral hemispheres smooth. Premaxillae 
and mandible expanded anteriorly and supporting a horny beak 
^ Blumenbaeh, Voigts Magazin, vol. ii. p. 205 (1800). 



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 Naturalist's Miscellany (vol. x., 1799). 
In the following year it was independently described by Blumenbach 
{Voigts Magazin, ii. p. 205) under the name of Ornithorhynchus 
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. 
Ornithorhynchus 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 afiinities 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 afiirmed, 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 Reptilia. Two eggs are produced at 
a time, each measuring about three-fourths of an inch in its lono- 
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 dififerent individuals have given rise to 
the idea that more than one species may exist ; but all naturalists 



ORNITHORH YNCHID.E 



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, 




Fia. 32. — Platypus or Duck-bill (Ormthorhynchus anatijius). 

AiLstralia. 



From Gould's Mammals of 



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. 



MONOTREMATA 



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 ^ announced the discovery 
in an embryo of teeth which were regarded as quite functionless. In 
the following year, however, Mr. 0. Thomas ^ 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 
diiference 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 amono- 
other known mammals Mr. Thomas considers, as was first suo-o-ested 
by Professor Cope, that those of the Mesozoic Multituberculata (p. 1 09) 
make the nearest approximation. He adds, however, that " it must 
be insisted that the resemblance between the Multituberculate 
^ Proceedings of the Motjal Society of London, vol. xliii, p. 353 (1888). 
= Ibid. vol. xlvi. p. 126 (1889). 



ORNITHORHYNCHIDM 123 

and the Ornitliorhynchus 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." 

Eeverting to the description of the Duck-bill, we 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 five 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 wth 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 
fw 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 efifected 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^. 

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 below the 
extremity of the rostrum. No teeth or laterally placed horny 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 laro-e 
perforation, as in Birds. Calcaneal spur and gland of the male 
much smaller than in Ornithorhynchus. Fur intermixed with strong 
sharp-pointed spines. Terrestrial and fossorial in habits, feedino- 
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- 
rhynchidce. According to Mr. 0. Thomas, all the living forms may 



ECHIDNID^ 125 

be included in two species, whicli, with some hesitation, are referred 
to two genera — Echidna and Froechidna (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, whUe 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 
New 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 yellow 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 skull 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 EUmentaire d'Hist. Nat. p. 143 (1798). 



1 26 MONO TREMA TA 



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. 

ProRchklna} — The one known representative of the genus 
Proechidna (Fig. .33) attains dimensions about equal to those of 




Fig. S3.— The Three-toed Echidna (ProccMtlna hruijnii). 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 bro■\^^l 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. 

' Gervais, OsUographie des Monotrcmes, p. 43 (1877). 



ECHIDNIDM 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. 
Krefft, but was subsequently called E. ram.sayi by Sir R. Owen. 
In referring this species to the genus Echidna, that term must be 
regarded as including Proechidna. 



CHAPTEE VI 

THE SUBCLASS METATHEEIA OE 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,! 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 
lurethra. 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 

^ For the detailed charaoters of all the genera and species of Marsupials the 
reader should consult the British Museum Catalogue of Marsupialia and Mono- 
tremata, by Oldfield Thomas, 1888. 



GENERAL CHARACTERS 



129 



attached for a considerable time, nourished by the milk injected 
into the mouth by compression of the muscle covering the 
mammary gland. They are 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 " (marsupium) 
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 
function until the 
animal has nearly, 
if not quite, attained 
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 




Fig. 34. — Teeth of upper jaw of Opossum (DidelpJiys mar- 
supiaHs), all of which are unchanged, except the last premolar, 
the place of which is occupied in the young animal by a molari- 
form tooth, represented in the figure helow the line of the other 
teeth. 



1 30 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, Thyladnus, they are not ossified. 
The number of dorso-lumbar vetebrse 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 cav£e,i 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 faeces, 
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 

' Except in Petaurus [Belideii^) brevkeps (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 do\vn the latter passage. 

Bistrifjutian. — The existing species of Marsupials are, with the 




Fig. 35. — Front view of skull of Sarcopliilus ursinus, showing polyprotodont and carnivorous 
dentition (Quart. Journ. Geol. Soc. vol. xxiv. p. 313). 



exception of one family (the Didel])hyklK), limited in geographical 



distribution to the Australasian region,^ forming the chief 
mammalian fauna of Australia, 
New Guinea, and some of the 
adjacent islands. The Didel- 
phyidw 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 „ „ . ^, ^ . ,-,,,, ir i /m 

^ Fio. 30. — Front view of skull of Koala {Pluis- 

grOUpS, it may be observed mlarctus chierms), showing diprotodont and 
that one of the most ob^^OUS herbivorous dentition (.Quart. Journ. Geol. Soc. 

distinctive characters among ^ "^' ^"^'' ''' ' 

them is derived from the form and arrangement of the teeth. 

^ Including the transitional Anstro-Malayan region. 




132 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 a,nd 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 Peramelidce 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 Marsupialia. 

A. PoLYPEOTODONTiA. — Inolsors numerous, small, subequal. Canines 

larger than the incisors. Molars with sharp cusps. 

o. Incisors |^. Hind feet with the four outer toes subequal, 
distinct, and a well-developed opposable hallux. Didel- 
phyidx. 

13. Incisors ^. Hind feet with four outer toes distinct. Hallux 
small or rudimentary, rarely opposable. Basyuridce. 

y. Incisors "7" ' . Hind feet long and narrow. Fourth toe 

larger than the others. Hallux rudimentary or absent. 
Second and third toes very slender, and vinited in a 
common integument (syndactylous). Peravulida;. 

B. DiPROTODONTiA. — Incisors not exceeding -I, usually -5-, but occasion- 

ally \. Central (first) upper and lower incisors large and 
cutting. Upper canines generally, and lower invariably, absent 
or small. Molars with bluntly tuberoulated or transversely 
ridged crowns. 

a. Teeth with persistent pulps. Incisors ^ large, scalpriform, 
with enamel on the oiiter surface only. No canines. 
Hind feet with four subequal outer toes, partially 
syndactylous, and with rudimentary hallux. Phascolo- 
myidce. 



DIDELPHYID^ 



133 



/3. Teeth rooted. Three upper incisors and a canine. Hind 
limbs not disproportionately large. Feet syndactylous, 
broad, with four subequal outer toes, and a large 
opposable hallux. PhcdangeridcE. 

y. Teeth rooted. Three upper incisors, and frequently a 
canine. Hind limbs disproportionately large, with 
syndactylous feet as in Peramelidce. Macropodidce. 



Suborder POLYPROTODONTIA. 

The leading 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 \, c \, p %, m ^ ; total 50. Incisors very small 
and pointed. Canines large. Premolars with 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. Cajcum 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 : 
7, D 13, L 6, S 2, C 19-35. 

The Didelphyidm, 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 the right hind 
foot of the Virginian Opossum (Didelphys 
marsupialis). 



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. 

Chirmedes.^ — The family comprises two genera only, namely 
Didelphys, containing all the species, with the exception of the curious 
Yapock, which forms by itself the genus Chironedes, 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.^ — 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 {D. marsupialis), 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 youno-, which 
commonly ride on their mother's back, holding on by ■\vindino- 
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 lUiger, Prod. Syst. Manim. et Avcs, p. 76 (1811). 
- Linn. Syst. Nat. Ed. 12, vol. i. p. 71 (1766). 



DIDELPHYID.-E 



135 



fourtli or Micoivreine, 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 (B. murina), little larger than a House-Mouse, 
and of a bright red 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, A^dth three clearly-defined deep-black bands 




Fig. 38. — The Woolly Opossum (DidelpTiys 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 Didelphys, but have been 
subsequently described as Peratherimn and Jmphijmrdheriwm. The 
characters of the molar teeth on which these genera are based do 
not appear to be sufficiently important to justify their separation 
from Didelphys. Allied forms occur in the Tertiaries of North 
America, which were originally described under the name of Her- 
petotheriwn, but have been subsequently referred to Peratherimn. 
Eemains of many of the existing species of Opossum are found in 
a fossil condition in the Pleistocene cave-deposits of Brazil. 



136 



MARSUPIALIA 



Family Dasyubid^ 

Dentition : i^,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 ICew Guinea 
and some of the adjacent islands. The aberrant genus MyrmeroiAus, 
though clearly a member of this family, is so sharply distinguished 




Fig. 39. — Tlie Tliylacine {lliijlaclRus i:}ino<:ephaIus). 

from all the others as to render a division into two subfamilies 
necessary. 

Subfamily Dasyurinse. — This comprises the more typical Dasy- 
uricke, 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. 

Thjladnus} — Dentition : i |, c \, p f, m -\ = \Q. 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- 
' Temminck, Monograpliies dc Mammal wjie, vol. i. p. 60 (1827). 



DASYURIDM 



137 



sembling those of Dasyurus, 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 
hair. Hallux (including the metacarpal bone) wanting. Vertebrae : 
C7, D13, L6, S 2, 23. Marsupial bones represented only by 
small unossified fibro-cartilages. 

The only known existing species of this genus, T. cynoceplmlus 
(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.— Kight 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, " Hysena." 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 f . Upper incisors nearly 
equal, and placed vertically, the first not difierentiated 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; 

^ F. Cuvier, EM. Nat. des Mammiflres, iv. (1837). 



138 MARSUPIALIA 



head disproportionately large for the body; muzzle short 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 
(8. 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 
Thyladnus. 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 
Thyladnus and other Polyprotodonts with three premolars it is the 
second that is missing. 

Dasyurus} — Dentition : i ^, c \, p |-, m -f- ; total 42. Upper 
incisors nearly equal, 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 
Vertebrae : C 7, D 1 3, 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 Carnivore, 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- 
^ Geoffroy, Bull. Soc. Philom. vol. i. p. 106 (1796). 



DASYURIDJE 139 



rinus, Tasmania and Victoria ; D. geoffroyi, nearly all Australia ; 
D. hallucatus, Nortt Australia ; D. albopunctatus, New Guinea. 

Eemains referred to D. viverrinus occur in the Australian Pleis- 
tocene deposit^. 

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 ■^,^ 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. 
Mammee 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. cristicavdata, 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 Chceiocercus 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.^ — The genus Sminthopsis 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.^ — 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 

^ Temminck, Monographies de Mammalogie, vol. i. p. 56 (1827). 

^ Thomas, Ann. Mus. Genov. ser. 2, vol. iv. p. 503 (1887). 

3 Krefft, Proc. Zool. Soc. 1866, p. 434. 



140 



MARSUPIALTA 



a long tail ^yitll 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. Zonl. Soc. 1880, p. 454. 

Subfamily Myrmeeobiinse. — Molars and premolars exceeding 
the normal number of seven on each side. Tongue, long cylindrical, 
and extensile. 

Myrmemhius} — Dentition : i -f, c \, p |, in -| or f ; total 52 or 56, 




Fig. 41. — ilyniuxubiusftisciatus. From Goiild. 

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 havino- 
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. Sw. 1838, 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. 
Vertebra: 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 English 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 (see p. 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^. 

Dentition : i "7 , c r, j? 5, ™ j ; total 46 or 48. Upper incisors 

small, with short broad crowns. Lower incisors moderate, nar- 
row, proclivous. Canines well developed. Premolars compressed, 
pointed. Molars vnth 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 Manis 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 Pemmelidce form a very distinct family, in some respects 
intermediate between the sarcophagous Dasyuridm 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 



142 MARSUPIALIA 



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 Avith the Diprotodonts, but o'iving 
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.'^ — Anterior and posterior extremities not differing 
greatly in development. Fore feet with the three middle toes well 



Fig. 42. — PeraiiuUs gujini. From Gould. 

developed, the third slightly larger than the second, the foui-th 
somewhat shorter, provided with long, strong, slightly curved 
pointed claws. First and fifth toes very short and mthout claws. 
Hind feet with hallux of one or two phalanges, formino- 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 wth short adpressed 
hairs. Fur short and harsh. Vertebra ; C7, Dl3, L6 Si C17 
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 Geoffroy, £uU. Soc. Philom. vol. iii, p. 249 (1S03). 



PERAMELID^ 143 

hollow places. They are 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 Aru, Kei, and New Ireland. The 
best known are — P. gunni (Fig. 42), bougainvillei, nasuta, obesula, and 
macrura from Australia, and P. doreyana, raffrayana, and longicaudata 
from New Guinea. 

Eemains apparently referable to existing species are found in 
the cave-deposits of New South Wales. 

Peragale?- — Molar teeth curved, typically vnih. 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 Eabbit - 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 Eabbit, 
to which animal it bears sufficient superficial resemblance to have 
acquired the name of " Native Eabbit " 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. 

Chmropus.^ — 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 

' Gray, in Grey's Australia, vol. ii. p. 401 (1841). 
2 Ogilby, Proc. 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 : 7, D 
13, L 6, S 1, 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 
Rat, found in the interior of the Australian continent. 
Its general habits and food appear to resemble those 
of the other Peramelidoe. 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. 



iir 



Fig. 4,3.— Skele- 
ton of right hind 
foot of Ghxropus 
castanotis, c, Cal- 
caneum ; a, astra- 
galus ; c&, cuboid ; 
n, navicular ; c3, 
ectocuneiform ; II 
and III, the con- 
joined second and 
third digits ; IV, 
the large and only 
functional digit : 
V, the rudiment- 
ary fifth digit. 



Family Phascolomyid^ 



Dentition : c \, i %, p \, m j^ = 21. .AJl 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, 
the concavity 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 
equal, stout, and short. Fore feet with five distinct toes, each 
furnished -\vith 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 with 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. Pouch present. The auditory 
bullae of the skull are imperfect, open behind, with their anterior 



PHA SCOL OM YIDM 



145 



wall formed by a descending process of the squamosal, instead of the 




Fig. 44. — Uioiropus ca^t'uiviis. From Gould. 



alisphenoid. Masseteric fossa of mandible with, a perforation and 
a deep pit. 




Fig. 45. — Common Wombat (Pliascolomjp nrsiiius). 

Phascolomijs?- — The existing Wombats (Fig. 45) comprise three 
1 GeofTroy, Ann. chi Museum, vol. ii. p. 365 (1803). 
10 



146 MARSUPIALIA 



spccios, nil of which aro iiu-liuloil in the (iiu< i^cnus I'lhisruloiii//.^, 
iviid all of which date from the Plcistdconc. 

In the typiciil j^roiip wo tiiul the followinj;- chai'Mctors. Fur 
rough and coarse. Kars short and rounded. MuHle naked. Post- 
orbital jivocess of the frontal bono obsoh'le. Kihs lifteen ])airs. 
Yertolnw: C 7, D 15, L 4, S 4, C 10-12. 'Hie Mdnd>at of Tas- 
mania and the islands of Bass's Straits (/' iirsiiiint) -.unl the closely 
similar but larger animal of the southern purlion of the mainland of 
Australia (/'. mitchclli) belong to this group. 

In the second grouj) the characters aro as follows. I'^ur smooth 
and silky. Ears largo and more pointed. Mutllo haii'v. Frontal 
region of skull broailer than in tlic other gron]i, with well- 
mai'ked ])ost.orbit,al processes. Ivibs thirteen. \'ertc>lira' : (' 7, 1) 
i;!, L 6, S 4, (' 1.5-lG. One spci'ics, 1'. /(ilifn>ii.'<. the ilairy-noscd 
AVombat of Smithern Australia. 

In their general form and actions tho Wombats resendile small 
bears, having a somewhat, similar shullling manner of walking, but 
they aro still shorter in the legs, and have broadi'r, Hatter backs than 
bears. They live entirely on the groniid, or in burrows or holes 
among rocks, ne\er climbing trinw, and f(H'd entii'cl)' on i;rass, 
I'oots, and other vegetable stdistances. They sleep during the day, 
and wander forth at night in search of tood, and are shy and 
gentle in theii' habits gcMierally, tlniugli they can bite strongly wln'n 
])ro\dked. Tho only noise, the conniion Wmnbat. makes is a hiw 
kind of hissing, but tho Hairy-nosed ^^'ombat is said to cnn't. a short, 
quick grunt when annoyc^d. The jircNailing colour of tlu' last- 
named s]»ccies, as well as of /'. iiyaiiuis of Tasmania, is a. brciwnish 
gray. The large wondiat of tho mainland is very \aria.lil(^ in colotu'. 
Slime individuals being found of a pale yellowish blown, nt hers 
dark gray, and some (|nit.e black. Tho length of head and budy is 
abind. throe feet. 

It is noteworthy that i-". ;(/?7f//r'///' was lirst described frnin (he 
ovidencu of fossil remains, tho living form subsei|uciitly described as 
P. )i;/(ri!//r/jMt«.s' being found to be iiidistinguisliable. Oilier extinct 
species occur in the I'leistoceiu^ of Australia. 

riiannildiiiis.' — K.eiiiains of a large extinct. Winiibat, which must 
have nearly ei|ualIod the diniensidiis of a 'I'a.pir, occur in tiio 
Pleistocene of t^m^-'-'i^*''^'"') '"t'l hinv, Ihhmi descrilicd as I'liasru/diiiis. 
It is jirobable that tho expanded and llat.teiicd upper incisors from 
the same, deposits upon the oviileiici^ of which (he prosnmed "'enns 
Scqiiirwiduii. was foinided, are likewise. I'ol'erabh^ to (he same foi'ni 
The characters of both tho upper ;iiid lower iiu'isors distiic-uisii 
I'liiiKiuilimiis from I'liiisrolfiiii !/■■<. 

, ^ Owi^ii, /'A/7. '/'I'dii.s, ls7',', p. 'j.sr. 



PHALANGERID.K \ 47 



FdliriliJ I'UALANaHUlD.K. 

T)oiititioii oxti'omoly \'iiriiil)lc, (iwiiig to the jn-t'sciico of minute 
nidimentol tooth not oonstunt in tho saiuo spocios, or ovon in the 
two sides of the jaws of tho sumo in(li\'idual ; oxoh;si\'o, hii>\ovor, of 

T(irsi/irs, t\\o ftn'nnila i j, c ^, p .Z ']., m -'^ j, roproseiits fairly tho 

goiioral condition of tlio fuuotioual tooth. First iiioisors long and 
stout ; tiio lowoi' piur \ cry largo and pointed, Imt without the soissor- 
Hki' iiotioii found in tho (wistiiig Macropodidw ; sooond and third 
lowor inoisors niinuto and pi'obably fnuotionloss. Foni'th proruolar 
gouorally sc'caut ; nnlk-niolar gonorally minute and dooiduous at an 
early period. Molars cither with sharp cuttiiig-ci'osts or Wuntly 
t\dioi\'ulato ; fourth sonictinios alisent. iMandiLlo without pit, and 
iit most a \oi'y miuute ])crfofation in ttu^ masseteric fossa. Limbs 
subeqnal. Fore foot with Hno distinct, subecpial toes, furnished with 
claws. Hind feet sliort and bi'oad, with K\o well-dovoUipod toes ; the 
hallux large, nailless and op|)osable ; tho second and third slender, 
and unittnl by a connnon integument as far as tho claws. Tail 
gonocally long, and frei(uontl\' more or less prehensile. Stomach 
simple, (.'ieciuii present (except in Tmvipcx), and usually largo. 
Pouch complete. Animals of small or moderate size and arboreal 
habits, ns\ially feeding on a \ogetable or mixed diet, inhabiting 
.Vnstialia and the Tapiian Islands. 

'riio homologies of tho lower fnnctionless tooth between the first 
incisor and fourth pi'omolar are Nory diflicult to dotcrmino, but 
it is probable that one rt'ini'sents a canine only when the largest 
known numboi' is jii'osont ; this tooth, according to JMr. Thomas, 
l)oing the tifst to disappear. 

I'halangers are small woolly-coatotl animals, with long, power- 
ful, and often prehensile tails, largo claws, and, as in the American 
opossums, with t)pposablo nailless great toes. Thoir expression 
seems in tho ilay to bo dull and sleepy, but by niglit thoy 
apjioar to decidedly greater aihautage. They li\o most!}' upon 
fruit, lea\es, and blossoms, although some few feed habitually upon 
insects, and all relish, when in continomoiit, an occasional bird 
or other small animal. JSeveral of tho I'halaiigors jiossoss flying 
n\eu>bi-anos stretcluHl between tiioir fore and hind limbs (Fig. 4S), 
by the help of which thoy can make long and sustained leaps 
through the air, like tho Klyiug 8(pnrrels, but it is interesting to 
notice that the possession of these Hying menilnanos dot's not seem 
to bo any indication of special atlinity, tho oharacters of the skull 
and tooth sharply dividing tho flying forms, and uniting them with 
other species of tho non-Hying groups. Their skulls (Fig. -17) 
are as a rule broad and llattoneil, with the posterior part swollen 



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 orienialis) 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 




Pio. K.—Tarsipes rostraUis. Prom Gould. 

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. 

TarsipesJ—So named from some supposed resemblance of its 

foot to that of the Lemurine genus Tarsius; 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 

^ Gervais and Verrau.x, Proc. Zool. Soc. 1842, p. ]. 



PHALANGERIDM 149 

and slender muzzle. Mouth - opening small. The two lower 
incisors are long, very slender, sharp -pointed, and horizontally- 
placed. All the 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 indiyidual. The formula in a specimen in the 
Museum of the Eoyal College of Surgeons is i f , c\, ]) and m f on 
one side, and -f on the other ; total 20. Rami of the mandible 
extremely slender, nearly straight, and without coronoid process or 
inflected angle. Fore feet with five well-developed toes, furnished 
with small, flat, scale-like nails, not reaching to the extremity of 
the digits. Hind feet rather long and slender compared with those 
of the Phalangerinos, having 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, 
D13, 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 Melaleucm, etc. One kept in confinement by Mr. 
Gould was 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} — 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 subequal, 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 mammse. Skull (Fig. 47) 

^ StoiT, Prodromus Mcth. Mamm. p. 33 (1780). Syn. Phalangisia, Geoffrey, 
£uU. Soc. Philom. vol. i. p. 106 (1796). 



ISO 



MARSUPIALIA 




Pig 47.— Left lateral view of skull of Gray Cusous (Ptei- 
ang&T 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 
* f J c T! i* f ) "* f • 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 Cuscuses are curious sleepy-looking 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 neighbourino- 
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. 

Trkhosurus?- — The members of the genus TrirhoKums 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 
i i, c hP h "» T- 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. vulpecuia), so common in 
^ Lesson, Did. Cla.is. t/'Hist. A\if. vol. xiii. p. 333 (182S) 



PHALANGERIDAl 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 (Petaunis australis) described 
below, except that it is unable to take the flying leaps of that animal. 
Like all the other phalangers, its flesh is freely eaten both by the 
natives and the lower class of settlers. 

Pseuclochirus} — The genus Pseudochirus 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 mammse. 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 bullae generally 
somewhat inflated. Dentition (at most) i ^ , c — q— , p ^, m ~. 

Upper teeth nearly uniform in length, but the first incisor distinctly 
longer than second. Upper premolars variable. Molars vnth both 
inner and outer cusps distinctly crescentoid, and recalling those 
of the Selenodont Artiodaotyle Ungulates. 

Range. — Tasmania, Australia, and New Guinea. 

There are about ten species of this genus known, of which the 
commonest is Cook's Eing-tailed Phalanger (Pseudochirus 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 following genus readily distinguish them from the more 
typical Phalangers, and show an approximation to the type of 
dentition prevailing in Phascolardus ; according, however, to Mr. 
0. Thomas, a tendency towards the same structure is observable 
in unworn molars of young Cuscuses. 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. Zool. 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. Eemains of Pseudochirus, probably 
referable to existing species, are found in the cave-deposits of New 
South Wales. 

Petauroides?-- — With the genus Petanroides, 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 premaxillse. Large vacuities in hinder part of 
palate. Auditory bullae inflated and smooth. Dentition usually 
« f ) c -J-, ^ f , in f. 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 aflSnity Avith 
Pseudochirus, although the external form is widely diff'erent in the 
two genera. This Phalanger seems, indeed, to be, so to speak, a 
very specialised Pseudochirus, in which the teeth have become 
somewhat fiu-ther diminished and the flying membrane has been 
developed. 

Dackjlopsila.^ — The genus Dactylopsila is one of the forms vnlh- 
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 lone, 
cylindrical, and evenly bushy, with the extremity more or less 
naked below. Skull narrow, but Math the zygomatic arches greatly 
expanded; palate fully ossified. Dentition: i f, c ^, p ^, m *. 
Upper incisors very large, the third being directed horizontal^ 
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. trivirgafa, or Striped Phalanger, inhabits the 
^ Thomas, Cat. Marsupials Brit. Mas. p. 163 (18S8). 
^ Gray, Proc. Zool. Soc. 1858, p. 109. 



PHJLA.XGERID.E 153 

Pajtuaii and North Australian sub-i'ogion ; a second species (D. 
paljiafoy), characterised by the still greater elongation of the fourth 
finger, oecm-ring in South !NeA\- Guinea. These animals are said 
to be of insectivorous habits, the elongated fourth finger, as in the 
analogous instance of the Lenuu'oid genus CIiiiviiii/:<, being appar- 
ently specially adapted for extractinqk insects and larA'a- from their 
hiding places. 

I'etitnni^.'^ — Size medium or small. Fur very soft and silky. 
A broad flying membrane extending from the outer side of the fifth 
digit of the maiuis 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 extrennty. Glands 
on the chest and between the ears. Skull short and vride, with 
the nasals expanded posteriorly, and usually two small palatal 
vacuities near the second moltu's. Auditory bulla? inflated, and 
variable in size. Dentition : / ii, c J, ^> j|, m j;. First upper incisors 
^■evy large, and taller than canine. J\Iolars with square crowns 
rounded at tl\e angles, and four cusps, except in the last, which is 
triangular. 

This genus, which ranges from N\m\- Ireland to South Australia, 
but is not found in Tasmania, contains three species, the largest of 
which is the Yellow-bellied Flying-Phalauger {F. australis), whose 
habits are recoi'ded by ]\[r. Gould as follows. "This animal is 
common in all the brushes of Ne^\■ South Wales, particularly those 
^^•hicl\ 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 oficr a never-failing supply of the blossoms 
upon ^^■hieh it feeds ; the flowers of the Aarious kinds of gums, 
some of which are of great magnitude, are the princijial favoiu'ites. 
Like the rest of the genus, it is nocturnal in its habits, dwelling in 
holes and in the spouts of the larger branches ciuring 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 exeejit for the jnu'pose 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 impcttis which, with the expansion of 
its membrane, enables it to pjtss to a considerable distance, always 
ascending a little at the extremity of the leap ; by this ascent the 
animal is prevented from recei^ ing the shock which it would other- 
wise sustain."' 

1 Slunv, Xaliirah'fl's Ji[i\<c:lhinii, vol. ii. pi. Ix. i,iriH\ 



154 



MARSUPIALIA 



A second species, P. sciureus, in some ways one of the most 
beautiful of all mammals, has been chosen for the accompanying 
■woodcut. 

Giimnohelideus?- — Like Pehmrus in exevx respect, but -n-ithout 
any trace of a flying membrane, and ivith 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. 




Fio. 4S.— Squirrel Flying-Plialanger (Petaimis sciuyeus). 

Bromiciu." — 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. .Vag. X. H. (3) x.\. p. 287 (1867). 
Gray, in Orcifs 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 ^, '^ u'f §> ™ fs^v 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 Petawus and Acrohates, 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. 

Diskechunis?- — Size small. Ears rather short, thinly covered 
with hair, but ivith 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 Acrohates, 
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 (D. pennatus) is 
found in New Guinea. 

Acrohates} — 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 ?,, c '^, p %, m %. Teeth sharp, 
and of an insectivorous type. Upper canine long, and approximated 
to third incisor. The three upper premolars large, fimctional, 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. pygmoius), 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 Phaseolaretinse. — Teeth large, normal; no rudi- 
mentary premolars before the last upper premolar, or any teeth 

^ Peters, Ann. Mus. Gcnov. vol. vi. p. 303 (1874). 
° Desmavest, Nouv. Diet. d'Hist. Nat. ser. 2, vol. xxv. p. 405 (1817). 



156 



MARSUPIALIA 



between the first lower incisor and fourth premolar. Tongue 
of ordinary structure. Distinct cheek-pouches. Stomach with a 
special gland near the cardiac orifice. Csecum 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 Phascoloniyidcey 

Phascolarctus.^ — Dentition : i^, c ^, p ^, 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 cro^vns, each bearing foxu- pyramidal cusps, ivith ciu-ved 
ridges radiating from them, and having a structure very similar to 
these of Pseudochirus. The lower 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 with 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. Yerte- 
brae: C 7, D 11, L 8, S 2, C 8. 
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- 
ereus), an animal of compar- 
atively large size and heavy 
build (Fig. 50), found in the 
south-eastern parts of the Aus- 
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. ISO 
2 Blainville, Bull. Soc. Philom. 1816, p. 116. 




E.FIG. 49.— Skeleton of right hiud foot of Koala 
{Phascolarctus cineretis), 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 connuon integument. 



tralian continent. 



PHALANGERID^ 



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 Phalangerklce, but 
further evidence is required before all these determinations can be 
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 Archizonurus which appears to be 




Fig. 50. — The Koala (Fhascolarctus cinsreus). 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}- — Dentition of adult: if, c-J-, j3-|, m-J; 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. ei Pal. fran(;aises, 1st ed. pt. i. p. 192 (1849-52). 



158 



MARSUPIALIA 



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 
Pludangeridce and 
Macropodidce, and 
its dentition com- 
Ijletely unlike that 
of any known pre- 
daceous animal, this 
view has been called 
in question. 

The dentition is 

nearer to that of the 

Mucropodida:, and the 




Fig. 51. — Front view of skall of Thylacoleo cctrnifex, restored. 
i natural size. From Quart. Journ. Geol. Soc. vol. xxiv. p. 312. 



existing Fhalangeridce than to that of the 

genus may be provisionally regarded as the type of a distinct 

subfamily of the former. 



Family Maceopodid^. 



Dentition 



(0—1) 2 



> -f 2' ™ 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 ridded 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 laro-e 
foramen. Hind limbs usually larger than the anterior ones and 
progression generally saltatorial. Fore feet with five dibits • hind 
feet syndactylous, the fourth digit being very large and strongly 
clawed ; hallux usually absent. Tail generally long and hairy 



MACROPODID.-E 



159 



large 



and 



'U 



M 



occasionally prehensile ; stomach sacculated. Pouch 
opening forwards. 

The Jlacropodidiv 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 
by peculiarities in the structure of their limbs, 
teeth, and other organs. They ^'arJ' in size from 
that of a sheep down to a small rabbit. The 
head, especially 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 disproportionate strength and magnitude, 
which gives them a peculiarly awkward appearance 
when moving about on all fours, as they occasion- 
ally do when feeding. Eapid progi-ession is, how- 
ever, performed only by the powerful hind limbs, 
the animal covering the ground by a series of 
immense bounds, dui'ing which the foie part of the 
body is inclined forwards, and balanced by the 
long, strong, and tapering tail, which is carried 
horizontally backwards. When not mo'^ing tliey 
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 liy 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 hj their bounding flight. 
The fore paws have five distinct digits, each armed 
with a strong curved claw. 

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 on!}' one exception) -srithout any 
hallux or great toe. It consists mainly of one A^er}' large and strong 
toe, corresponding to the fourth of the human or other typically 
developed foot, ending in a strong, cui'ved, 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 
sldn, may be of use in scratching and cleaning the fiu- of the 
animal, but the toes themselves must have quite lost all connexion 
^vith the functions of support or progression. 

The dentition of the Kangaroos, functionally considered. 



Fin. 51:.— Skeleton 
of right hind foot of 
Kangaroo. 



i6o MARSUPIALIA 



consiits ijf sharp- edged incisor?, nnjst fully developed near the 
median Une cI the mouth, iC'i' the pmpijse 'jf cropping the various 
kinds •;■! herbage on which they feed, and ridged and tuberculated 
molars for crushing it, there being no tiisks or canines for oflensive 
or defensive purposes. 

The number of vertebra; is — in the cervical region 7, dorsal 13. 
lumbar 6, sacral 2. caudal varvinsr accordins to the length of the 
taU, but generally from 21 to 2-5. In the fore Hmb the cla-sicle 
and the radius and ulna are well developed, allciwino- of considerable 
freedom of motion of the hand. The pelvis has large epipubic or 
"marsupial'" bones. The femiu is short, and the tibia and fibula 



Fig. Co.— 'Hie Gr-.c: Gray Ear. jar i'i (A/.i.-roj>iij jri<7c ;. is). 

are of gTeat length, as is the foot, the whole of which is applied to 
the ground when the animal is at rest in the upright position. 

The stomach is of large size, and very complex, its w;ills being 
puckered up by longitudinal muscular bands into a gi-eat nimiber of 
sacculi, Hke those of the human colon. The aHnientarv canal is 
long, and the ca?cum 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 foiu" nipples. In this 
pouch the yoimg are placed as soon as they are born : there their 
gro-n-th and development proceeds ; and to "it they resort tempor- 
arily for the pm-pose of shelter, concealment, or transport, for some 
time after they are able to run and jiunp about the srotmd and 
feed upon the same heritage which forms the noiu-ishnient of the 
parent. Diuing the early period of their sojoiu-n in the pouch 



MACROPODIDAL i6i 



the blind, naked, helpless young creatures (which in the Great 
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 natiu-ally do in consuming the grass, now 
required for feeding cattle and sheep. Notmthstanding 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, which belong, in the zoological sense, to the 
ATistralian 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 Macropus, 
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 



i62 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 f 4 be still 
buried there (in which case, of course, that first tooth is only ^ 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 j? 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 Macropodidoi are divided into three well-marked sections : 
(1) the true Kangaroos (Macropodince) ; (2) a group consisting of 
smaller animals, commonly called Eat Kangaroos, or (improperly) 
"Kangaroo Eats," or sometimes Potoroos ; and (3) the Hypsiprym- 
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 Plialanger. Other teeth as in the Potoroince. 

This subfamily is now represented only by the genus Hypsi- 
prymnodon} which is a form of great interest, as showing a structure 
of foot connecting that of the Kangaroos with that of the Phalan- 
gers. The single known species, H. moschahis, was described by 
Eamsay from specimens discovered in north-east Australia. It 
was described almost simultaneously by Owen under the name of 
Pleopms nudicaudahis. 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 Macropodidce. 

TricUs.'^ — 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 Hypsiprymiwdon. 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 
Phalangeridm and Macropodidm than any other. 

Subfamily Potoroinse. — The second section or subfamily, the 

Potoroince, 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. iV. S. Wales, rol. i. p. 33 (1876). 

2 De Yin, Proc. Roij. Soc. QuecnsJmid, ser. 2, vol. iii. p. 8 (1888). 



MACROPODIDJE 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 being either set in the same line with the 
molars, or slightly bent outwards. Molars with cjuadrate 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 Eat 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 




Fig. 54.— Skull and Teeth of Eat Kangaroo (Bettongia Icsuadri). 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} — Head long and slender. Auditory bulte some- 
what inflated. Ridges on premolars few and perpendicular. 
Large palatine foramina. Tarsus short. Mufile naked. Three 
species, viz. P. tridadylus, P. gilberii, and P. platyops ; the last two 
being confined to West Australia. 

Bettongia.''' — Head comparatively short and broad. Ears short 
and rounded. Auditory bullse generally much inflated. Large 
palatine foramina. Tarsus long. Ridges on premolars numerous 

' Desmarest, Kouv. Diet. cl'Hist. Nat. ser. 1, vol. xxiv. Talle Meth. ]>. 20 
(1804). Syn. Hypsiprymnus, lUiger, Frodromus Syst. Manvm. p. 79 (1811). 
- Gray, Charlcsworth' s Mag. Nat. Hist. vol. i. p. 584 (1837). 



1 64 



MARS UP J ALIA 



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. penicillata, 

B. cunicidus, B. gaimardi, B. lesueuiri. 

Calop-ymnus?- — 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. 




"' / 








Fig. 65.— Skull and Teeth of the Red-necked Wallaby (Macropus ruficolUs). i', ;■-, P, First, 
second, and tliird upper incisors ; pm, fourth or posterior premolar (the penultimate or third 
having been already shed) ; ml, mS, »«3, mi, the four true molars. The last, not fully de- 
veloped, is nearly concealed by the ascending ramus of the jaw. 

JSpyprymnus.^ — Head short and broad. Auditory bullas 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. Eepresented only by ^-B. riifcscens. 

Remains of yE. rnfescens occur in the Pleistocene cave-deposits 
of New South Wales. 

Subfamily MacFopodinse.— 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. Mits. ji. 114 (1888). 
= Garrod, Froc. Zool. Soc. 187,5, p. 59. 



MACROPODIDJL 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 subequal 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 will be as follows : 

Lagostrophus} — ^Represented only by the Banded Wallaby 
{L. fasciatus) of Western Australia, which presents the follovnng 
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. 

Dendwlagus.^ — 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. IwmhpUzi is found in North 
Queensland. They diff'er 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 Mliller, Verh. Nat. Ges. Nederland, p. 138 (1839-44). 



i66 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. 

Dm-copsis.''- — Hind limbs relatively less large than in Macropus. 
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 which are from 
New Guinea ; the type being D. muelleri. 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 madeayi 
connects the other species with Macropus. 

Lagorchestes.^ — Muffle entirely or partially covered with hair. 
Fourth hind digit ivith 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. Iqxmidcs, M. 
Mrsiitus, M. conspicillatus. 

The range extends over the whole of Australia, but does not 
embrace Tasmania. 

Onychogale? — 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 bullje more or less inflated. Canine 

' Schlegel and Miiller, Verh. Nat. Ges. Nedcrlatid, p. 130 (1839-44). 

- Gould, Monograph of Macropodidx, pi. xiii. (1841). 

3 Gi'ay, in Grey's Aiistralia, vol. ii. appendix, p. 402 (1841). 



MACROPODID^ 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 Lagorchestes. 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. 
Skull as in the smaller species of Macropus, with large posterior 
palatal vacuities, and the bullae 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. peiiicillata 
is a Avell-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 F. xanthopus, P. penicillata, P. lateralis, P. amcinna, P. 
hradiyotis, P. inornata. 

Remains of P. penicillata are found in a fossil state in the 
Pleistocene cave-deposits of New South Wales. 

Macropus.'^ — 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 mammae. Skull (Fig. 55) long, 
smooth, and rounded ; the nasals expanded behind ; generally large 
palatal vacuities ; and the auditory bullsB 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 Anth an infolding of enamel 

' Gray, Charlesworth's Mag. Nat. Hist. vol. i. p. 583 (1837). 
^ Shaw, Naturalist's Miscellany, vol. i. pi. xxxiii. (1790). 



i68 MARSUPIAL/A 



near its postero-external angle. Fourth upper premolar with a 
secant edge, and an inner basal ledge or tubercle ; corresponding 
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, 
wth 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 sjjecies varying from that of a Kalilnt 
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 Now 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 frequently have 
a median longitudinal bridge connecting the first transverse ridge 
■\\ith 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 ri\-er on the north -oast coast of 
Australia, a strange-looking animal, entirely unknown to them, was 
frequently seen by the ship's company; and it is recorded in the 
annals of the voyage that, on the 14th of July 1770, "Mr. Core, 
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 natiAos kanguroo," a 
name which, though it does not appear to be now known to any of 
the aboriginal tribes of the country, has l)oen 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 traAeller Brnyn 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 aflinities of the species, skins of which wore brought 
home by Captain Cook and subsequent voj'agors, wore rcoooiiised 
by Schreber as nearer to the American opossums (then the only 
known Marsupials) than to any other mannnals with which zoologists 
were acquainted, and consequently it was jilaood by him, iii" his 
great work on the Mammalia, then in the coiu'so of publication, in the 
genus Didelphytf, with gigavtea for a specific designation,- — the latter 
having been bestowed upon it by Zimmermann under the impression 



MACROPODID^ 



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 iigure being 
given in the woodcut on p. 160. 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 M. riifus, the great Red 
Kangaroo, 3i. antilopinus, and 71/. rohustus. The fourth premolar is 
of large or medium size in these forms. Remains of BI. giganfeus 
occur fossil in the Pleistocene of Australia, where we also find the 
allied extinct M. titan, which attains somewhat larger dimensions. 
M. rohustus also dates from the same geological epoch, where it was 
accompanied by two allied types known as M. alius and M. coopieri. 

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 applied to them. There are several 
species, of which M. ruficoUis, M. ualaMtus, M. jmrriji, and M. agilis 
are the best known. 

M. ualabatus and M. 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 M. hrehus, in which the skull was probably about 
one foot in length, and M. rcechus, and M. 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, i 

The third and last group of the genus includes the small 

■^ For the characters of these species and the undermentioned distinct genera, 
see O^ven's Extinct Mammals of Australia (1877), and Lydekker's Catalogue of 
Fossil Mammalia in the British Museum , pt. v. (1887). 



1 70 MARSUPIALIA 



Wallabies, which are small and lightly-built animals, in some 
instances not larger than a Eabbit. 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. h'uni, belongs to 
this section. Several examples were 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 (Reizen over 
MosJwvie, etc.) under the name of "Filander." It was quite lost 
sight of, and its name even transferred "by S. Miiller to another 
species (Dorcopsis muelleri), until rediscovered in 1865 by Eosenberg, 
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- 
idm, to which brief reference may now be made. The first of these 
is Sthenwnis} 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 - 
the premolars resemble those of Sthenurus, 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 lart^e 
vacuities. Three species are known. The largest representation of 
the whole family is the type of the genus Palorchestes ^ (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. 

' Owen, Fhil Trans. 1874, p. 264. 
2 Owen, op. at. p. 788. » Owen, op. cit. p. 797. 



EXTINCT FAMILIES 



171 



Extinct Fajviilies. 

Here 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 Macropodklce and the Fhalangeridce in having 
-f- 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 be determined. 

Diprotodon,} — Dentition : i f, c -g-, j? ^, m f ; total 28. The first 
upper incisor very large and scalpriform (Fig. 56). True molars 
with prominent transverse ridges, as in Macropis, 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 







^W 



KiG. 56. — Left lateral aspect of the skull of Diproiodon australls; from the Pleistocene of 
Australia. ^^ natural size, i. Incisors ; p, i^reraolar; 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. D. 
australis is the largest known Marsupial, being fully equal in bulk 
to a Rhinoceros. It may be regarded as the type of a family — 
Diprotodontklce — having affinity on the one hand with the Phalangers 
and on the other with the Kangaroos. 

Nototheriumr — Eepresented by a species of somewhat smaller 
size than the type of Diprotodon, mth a shorter skull, in which the 
zygomatic arches are very wide and the nasals curiously expanded 
at their extremities. The mandibular symphysis is ankylosed ; 

' Owen, in Mitchell's Eastern Australia, 2d ed. vol. ii. p. 362 (1838). 
2 Owen, Cat. Mamm. and Aves, Mus. R. Coll. Surgeons, p. 314 (1845). 



172 MARSUPIALIA 



and, as in Diprotodon, there appears to have been no tooth-change. 
The humerus probably referable to Nototherium 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 Nototheriidce may apparently be regarded as a 
distinct family connecting the Diprotodontidce with the Fhasco- 
Imnyidce and Phalangeridce. 

Bibliography of Marsupialia. — G. R. Waterhouse, Nat. Hist, of the Mammalia, 
vol. i. "Marsupiata," 1846 ; J. Gould, Mammals of Australia, 1863 ; E. Owen, 
article "Marsupialia," in Cyclop, of Anatoviy 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 Dasyuridee," Phil. Trans. 1887 ; and "Catalogue of Mar- 
supialia and Monotremata in the British Museum, 



CHAPTEE VII 

THE SUBCLASS EOTHEKIA AND THE OKDEE EDENTATA 

The whole of the remaining groups of mammals are included in a 
single subclass, known by the names Eutheria, Monodelphia, or 
Placentalia.i 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 diphyodont dentition 
the dental formula can be reduced to some modification of the one 
given on p. 25, there being only one known genus where 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 

^ The characters of the chief gi-oups 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, mth 
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 more 
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 we 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 Ungulata, represented in the actual fauna by the Horses, 
Rhinoceroses, Tapirs, Swine, and Euminants. Almost as isolated 
as the Proboscidea among existing mammals are the few small 
species constituting the family Hyracida, 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 Ungulata, 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 Ungulata so far extended as to receive them all, in which 
case both Proboscidea and Hyracoidea may be included within it. 
Again, the Kodentia or gnawing animals — Eabbits, Eats, Squirrels, 
Porcupines, Beavers, etc. — are, if we look only at the present state 
of the class, most isolated. No one can doubt what is meant by a 
Eodent 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 Typotlierium, half Eodent 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 Eodents 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 which the Insectivora were 
modified into Chiroptera shown us by the so-called Flying Lemur 
(Galeopithecus). Finally, we have the important and well-character- 
ised group called Primates, including all the Monkeys and Man ; 
and the question is not j^et solved as to how and through what 



176 EDENTATA 



forms this is linked on to the other groups. It is commonly assumed 
that the Lemm-s 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 j)osition 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 palseontological 
researches have already gone far to show that they are all modifica- 
tions of a common heterodont, diphyodont, pentadactylate form. 



Order Edentata. 

The name assigned to this group (which some zoologists think 
ought rather to be ranked as a subclass ^ than an order) by Cu^•ier 
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 
quite 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. Eleplut^, TricJwcliu.% 
Bradypiis, Mijrimcophaga, Manis 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 Elephas stands first in the 
list of genera in the ,S//stema Nutimv. Cuvier's order included the 
OrnUhorhyndms 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, \vith the 

' The name Pavathcria has 1ieen sugge.sted for this proposed subclass. 



GENERAL CHARACTERS 177 

remarkable exceptions of Tatusia and Oryderopus, 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 mouth, 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 genus. As a rule, the 
coracoid process of the scapula of the Edentates is more developed 
than in other Eiitheria. 

The degree of development of the brain varies considerably in 
the different families, the 

hemispheres being in some ,.-^s=^^^S^ ^^niZ-tS^j^i! 

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 , ^'°; "l-"^?^^' TJ^'""' °^ *"' l"™" °"if ^T^' 

■,-,■.■. . banded Armadillo (Xenurus nnicmctm). The large 

tnat, beyond, the negative olfactory lobes are seen at the anterior extremity 
characters just mentioned, 0^^^ of figure); the hemispheres have only three 

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. 
Palaeontology 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 

^ In some few ArmadOlos the suture between the premaxilla and maxilla 
passes behind the first upper tooth ; but in all other known members of the order 
all the teeth are implanted in the maxilla. 

12 




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 we 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) Oryderopodidm, 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 
Bradypodidce alone; and (2) the Entomophaga, insect-eaters, or 
Vermilingua, containing all the other families, from which some- 
times the Oryderopodidce are separated as a third suborder under 
the name of Effodientia, 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 Chamagleon 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 ^ 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, Megaiheriidce, and Myrmecopliagidce 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 (he Zoological Society, 1S82, p. 358. 



BRADYPODID^ 179 



vorous, 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 {Dasypoclidce) 
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 MarMce and Oryderopodidce are 
so essentially distinct, both from the American families and from 
each other, that it may even be 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 Oryderopodidce?- 



Family BRADYPODiDiE. 

Externally clothed with long, coarse, crisp hair. Head short 
and rounded. External ears inconspicuous. Teeth ^ 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 

^ An attempt has been made to represent these views hy the following 
classification : 

Order EDENTATA. 

Suborder Pilosa. 

Bradypodidie. 

Megatheriidie. 

MyrmecopJiagidce. 
Suborder Lokicata. 

JDasypodidce. 
Suborder Sqttamata. 

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," Froc. Zool. Soc. 1883, p. 178. 



i8o 



EDENTATA 



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 luider them, with their backs downwards 
(Fig. 58), and clinging to them with the simple hook-like organs to 
which the terminations of all their Hmbs 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 



"''A«j.- 




Fig. 68.— Two-toed Slotli (Cholcepus koffmanni). 

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 -vvind 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 di-ao-o-ino- 
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 vrith which the 



BRADYPODID^ 



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 
is 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, inofi'ensive, 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 BradypodidcR, as well as in the Myrmecophagidce, the 
testes are placed close to each other, lying on the rectum between 
it and the bladder ; the penis is quite 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, mthout 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 Cholmpus is composed 
of a number of lobes aggregated into a dome-Kke 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 aflinities with a very primitive type of mammalian 
organisation. 

The Sloths were all included in the Linnsean genus Bradypus, 
but Illiger very properly separated the species with but two claws 
on the fore feet, under the name of Cholcepus, leaving Bradypus 
for those with three. 

Bradypus? — 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. Vertebrse : 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 vertebrse 
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. 
^ Linn. Syst. Nat. 12th ed. vol. i. p. 50 (1766). 



EDENTATA 



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 mammas 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 tridadyhis. More recently Dr. Gray described as many 
as eleven species, ranged in two genera, Bradypus and Ardopithecus ; 
but the distinctions which he assigned both to species and genera do 
not bear close examination. Some are covered uniformly ^Wth a 
gray or grayish-brown coat ; others have a dark collar of elongated 
hairs around the shoulders {B. torquatus) ; 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 shoulders, 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 diiferences in 
the skulls, as in the amount of inflation of the pterygoid bones, 
which indicate real differences of species ; but the materials in oui' 
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. cai^taneifips) 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 sovmd like a monkey 
when forcibly pulled away from the tree to which it was 
holding. 

Gholmpus} — Teeth -J: ; 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 (Fif. 59) 

^ Illiger, Prodromus Syst. Mamm. el Avium, p. 108 (1811). 



MEGA THERIID.E 



183 



unlike the true canines of heterodont mammals. Vertebrae : C 6 
or 7, D23-2-i, L 3, S 7-8, C 4-6. One species (C. didadylus) has 
the ordinary number of vertebra? in the neck ; but an otherwise 
closely allied form [G. hoffmanni) has but six. The tail is very 
rudimentary. The hand generally resembles that of Bradypiis ; 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. 
G. didadylus, ^Y\dch. 
has been longest 
known, is com- 
monly called by 
the native name 
of Unaii. It in- 
habits the forests 
of Brazil. G. hoff- 
manni (Fig. 58) 
has a more north- 
ern geographical 
range, extendine 




-Skull of Two-toed Sloth (Cholcepiis didactyhis). From 
Froc. Zool. Soc. 1871, p. 432. 



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} — 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 Chnlapus didadylus. 
Professor Cope states, however, that this jaw really belongs to a 
Glyptodont ; while it is referred by Dr. Ameghino to the next 
familJ^ 



Family Megatheriid.e. 

The members of this family are all extinct. Their characters, 
so fai' as is known from the well-preserved remains of manj' species 
found abundantly in deposits of Pleistocene age in both North and 
South America, were intermediate between those of the existing 
Bradypodiihr and the MyrmecopluKjidce, combining the head and 
1 Burmeister, Siizh. Al: Berlin, vol. xxviii. p. 613 (1882). 



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.^ This genus, and in a still 
more marked degree Megatherium, differ 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 




Pig. 60.— Section of upper molar teeth of Megatherium nmerka%nm. x J. 
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, Macropus, and others, though pro- 
duced in a diflFerent 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 grindino- 
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 Lydokker, in Nicholson and Lydekker's Manual of Palccontology, vol. ii. 
p. 1299 (1889). Originally described under the preoccupied name Ccelodon. 



MEGA IHERIID^ 185 



of this family may be conveniently designated, agree ■with the 
Sloths and Anteaters, and thereby differ 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 
Eiver Luxan, near Buenos Ayres, and sent in 1789 to the Eoyal 
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.^ In 1832 an 
important collection of bones of the Megatherium was discovered 
near the Rio Salado, and secured for the Museum of the College 




Fig. 61. — Oral surface of mandible oi Megatherium americanum. 
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 E. 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 {M. 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, ivhieh unfortunately was incorrectly 
articulated, and wanted the gi'eater part of the tail, was published by Pander 
' and D'Alton in 1821, and has been frequently reproduced iu subsequent 
works. 



i86 



EDENTA TA 



basin of the Eio de la Plata. Dr. Leidy lias described, from similar 
formations in Georgia and South Carolina, bones of a closely allied 
species, about one-fourth smaller, which he has named M. mirahile. 
Three other South American species have been described ; but M. 
Imirillardi, 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 amerieanmn. 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. 62, 



-Skeleton of Megatherium, from the specimen in the Museum of the Eoyal 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 Avide gap between the extremity of 
the nasals and the premaxillaj exhibited in Fig. 62, there was 
a prenasal bone, towards which a process extended upwards and 



MEGA THERIIDjE 187 



backwards from the extremity of the upper surface of the pre- 
maxillee. 

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 
Anteaters. 

The tail is large, and its basal vertebrse havd 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 
large, 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 



EDENTA TA 



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 whole 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 we may therefore imagine with 
a covering of coarse hair like that of its nearest living allies, the 
Sloths and Anteaters. 

Scelidotlieriwm, Mylodon, etc. — Of the more important remaining 
genera of this family a briefer notice will suffice. Scelidotheriiim (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- 
epioondylar foramen ; and the form and relations of the bones of 



MEGA THERIID^ 



189 



the feet differ considerably from those obtaining in the type genus. 

S. leptocephalum, 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 be taken to 

include a number 

of comparatively 

large Edentates, 

some of which have 

been described 

under the names of 

Chypotherium, Lest- 

odon, and Pseudo- 

lestodon. The teeth 

of the upper jaw 

are generally of an 

oval or subtriangu- 




Pm. 63.— Skeleton of Mylodon. rohmtus (Pleistocene, South 
America). From Owen. 



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. (GrypotJierium) 
darwini is a remarkable form, characterised by the presence of a 
bony arch connecting the premaxillse with the nasals, of which, as 
already mentioned, there is an Incomplete development in 
Megatherium. 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. Nothrotherium 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, Eeinhardt, 
and others. 

Promegatherium. — Two genera from the infra-Pampean beds 



I go EDENTATA 



of Argentina, described as Promegatlierium and Proinylodon, are 
respectively distiaguislied from Megathmum and Mylodon 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 Xorth American forms described as Jlorojjus and 
Morotherlum} and originally regarded as Edentates, would appear to 
be aberrant Ungulates. 



Family MYR5IEC0PHAGID.E. 

Externally clothed with hair. Xo teeth. Head elongated, 
ilouth tubular, with a small terminal aperture, through which the 
long, vermiform tongue, covered Avith the viscid secretion of the 
enormous submaxillary glands, is rapidly protruded in feeding, and 
withdrawn again with 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 
vertebrfe, 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 Xeotropical region. 

The reproductive organs, as noticed on p. ISl, are of the 
same general type as in the Bradypodidce. 

Myrmcajpliacia.'^ — Skull greatly elongated and narrow, its upper 
surface smooth and cylindriform. Anteriorh' the face is produced 
into a long, tubular rostrum, rounded above and flattened below, 
■^vith terminal nares, and composed of the mesethmoid ossified 
for more than half its length, the vomer, the maxillEe, and the long 
and naiTOw nasal bones, the premaxillaB being extremely short and 
confined to the margin of the anterior nares. The zygomatic arch 
is incomplete, the styhform jugal only articulating ^ith the maxilla 
in front, and not reaching to the very short zygomatic process of 
the squamosal. The lachrymal foramen is in front of the maroin of 
the orbit. There are no postorbital processes to the frontals, or any 
other demarcation betAveen the orbits and the temporal fossee. Palate 
extremely elongated, and produced backwards as far as the level of 

' See E. D. Cape, Amcr. Xaturalist, vol. xxiii. p. 152 (1SS9\ 
^ Linn. Sjjst. Xat. 12th ed. vol. i. p. 51 (1766). 



MYRMECOPHAGIDyE 191 

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 csecum. Mammae two, 
pectoral. 

There is one species,^ 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 

■' Professor Cope has recently come to the conclusion that there are three 
species ; but further evidence is required in support of this view. 



192 



EDENTATA 



burrow underground like the Armadillos. Thougli 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 {TaUisia), 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 




Fig. 64.— The Great Anteater (ilyrmecojihaga jubaki). (Prom Sclater, List of Animals in 
Zoological Society's Gardetis, 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). 

Tamandua} — 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 throu<rh- 
out and the whole of the terminal portion naked and scaly. The 
stomach is similar to that of Mynnecophaga, but with the muscular 
pyloric gizzard not quite so strongly developed. There is a distinct 
ileo-colic valve and a short globular cascum. The fore foot has a very 
large claw on the third toe, moderate-sized claws on the second and 
1 Gray, Annals of Philosophy, new series, vol. x. p. 343 (1825). 



MYRMECOPHA CrlDM 



193 



fourth, a very minute one on the first, and none on the fifth, which 
is entirely concealed within the skin. The hind foot has five 
subequal claws. Vertebree : C 7, D 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. 65. — Tamandua Anteater {Tamandua tetradadyla). From Prop. Zool. Soc. 1871, 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. 

Cydoturus} — 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. Vertebrse : G 7, D 16, L 2, S 4, 40. Eibs 
remarkably broad and flat. Clavicles well developed. Manus 
remarkably modified, the third digit being gi'eatly 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 

^ Gray, Amials of Philosophy, new series, vol. x. p. 343 (1825). 
13 



194 



EDEiXTATA 



is also completely modified into a cHmbing organ. The liaUirs: 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 

foregoing genera. Commence- 
ment of the colon provided with 
two small cseca (Fig. 66), resem- 
bling those of many birds, narrow 
at the base, and rather dilated 
at their terminal blind ends, and 
communicating with the general 
cavity by very minute apertures. 
Tail longer than the body, taper- 
ing, bare on the under surface, 
and very prehensUe. Fur soft 
and silky. 

This genus has also but one 
species certainly known, the Little or Two-toed Anteater (C. di- 
dadi/lus), an animal not larger than a Rat, of a general yeUowish- 
colour, and exclusively arboreal in its habits. It is a native of 
the hottest parts of South and Central America. 




Fig. 66. — Csca of the Two-toed Anteater 
(Cydoturus didactylus). i, neum ; 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 Umbs 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 



DASYPODIDJE 195 



monopiiyodont, but 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, axikjr 
losed together both by their bodies and arches. Lumbar vertebrae 
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 burrow 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, Ghlamy- 
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 Dasypodidm 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 



196 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 Chlamydophorinae. — In most anatomical characters, 
especially the structure of the fore foot, this little group resembles 
the DasypodviuB ; but it differs remarkably from aU other known 
Armadillos, living or extinct, in the peculiar modification of the 
dermal armour. 

Q 

Chlamydopliorus} — 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. Tertebrse : C 7, 
D 11, L 3, S 10, C 15. Upper part of head and trunk covered -vnth 
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 pehne 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 pehis. 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. Eves and 
ears very small, and concealed by the haii\ Extremities short. 
Eeet large, each with five well-developed claws, those on the fore 
feet very long, stout, and subcompressed, the structui'e of the digits 
being essentially the same as those of Xi'iiurm and Priodm. Nipples 
two, pectoral. Visceral anatomy closely resembling that of Dasymis, 
the caecum being broad, short, and bifid. 

The Pichiciago (C. tmncatm), a small burromng animal, about 
5 inches long, inhabits the sandy plains of the western pai-t of the 
Argentine Kepublic, especially the ncinity of :\Iendoza. Its 

1 Harlan, Ann. Xcw York Zi/ccum Xat. Rut. vol. i. p. 237 ns2i) — 
Amended from Chiamyplwrus. 



DASYPODID^ 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, 6'. 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 Das3T)odmse. — 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. Dasyjms, 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. Mammae one pair, 
pectoral. 

Dasypus.^ — Teeth -^^ or |-, of which the anterior in the upper 
jaw is usually implanted 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 Dasypodince 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. Vertebrae : 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). 



EDENTA TA 



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 (D. sexdndus) of 
Brazil and Paraguay. A very similar species, B. villosus, the Hairy 
Armadillo, replaces it south of the Rio Plata. There are also two 
very small species — JD. vellerosus, from the Argentine Eepublic and 
North Patagonia, and B. minutus from La Plata. The latter differs 
from the other three in having no tooth implanted in the pre- 
maxillary bone. Eemains apparently referable to B. villosus occur 
in the Pleistocene cavern-deposits of Brazil. 

Xenurus} — Teeth f 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, CIS. 
Head broad behind. Ears rather large and rounded, wide 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, mth 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, X. hispiclus and hgubris, 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, S^/st. Amphihien, etc., p. 36 (1830). 
2 F. Cuvier, Hist. Nat. dcs Mammiflres {lS22).—Friodontes. 



DASYPODIDJE 199 



all very small ; those in the anterior half of each series being strongly 
compressed, with flat sides and a straight free edge ; the posterior 
ones are more nearly cylindrical, with flat truncated, free surfaces. 
Vertebrae: 7, D 12, L 3, SIO, 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 Xenurus, 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, fiat, 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. 

Tolypeutes} — Teeth ^ or -I, 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. Vertebrae : C 7, D 11, L 3, S 12, 
C 13. Ears placed low on the sides of the head, rather large, 
broadly ovate. Carapace with 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 
filling 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 quickly, with a very peculiar gait, only 
the tips of the claws of the fore feet touching the ground. Three 
species are described: — T. tricinctus, the Apar; T. conurus, the 
' lUiger, Prodromus Syst. Mamm. et Avium, p. Ill (1811). 



EDENTA TA 



Matico ; and T. muriei. Eemains ajDparently referable to T. conurus 
are of not uncommon occurrence in the Brazilian cavern-deposits. 

Subfamily Tatusiinse. — This group contains but one genus, 
Tatusia} Teeth ^ or \, very small subcylindrical. The first and 
second subcompressed, the last considerably smaller than the others. 
They present the remarkable p)eculiarity (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. 




Fio. 67.~The Peba Armadillo (Tatusia novemcinctn). 

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 taperino- ; 
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 cm-ved, 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 difi-ers from all the other Armadillos in ha^-ino■ a pair 
of inguinal mamma?, in addition to the usual pectoral paii^^and in 

1 Lesson, Man. de Mamma!o;/ic, p. 309 (1827); ex. F. Cuvier, TatKsic. 



DASYPODID^ 



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. owvemcinda (Fig. 67), 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- 
phradus pilosus and Praopus 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. novemcinda, 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.^ 

In the Pleistocene cavern -deposits of Brazil have been found 
remains of T. novemcinda, and also of T. punctata, which appears to 
be an extinct form nearly allied to' T. happleri, 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. Dasypotherium 
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 Ghlamydotherium, 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 hrunetti {Ann. Sc. Nat. xvi. p. 8, 1872). 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 
alniost 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 Glyptodontid^. 

In the Pleistocene cavern -deposits of Brazil, but still more 
abundantly in the fluviatile 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 diiFer from the existing 
Dasypoclidm 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 skiill 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 -g in the known species, 
all much alike, having two deep grooves or 
flutings 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 iigured, especially by 
Burmeister (in the Jnnale.'i del JIii^co publico dc 
Buenos Aires), among which the following may 
be noticed. Hoploplim-us is characterised by the sculptured and 
frequently thin scutes of the carapace, those of the periphery being 
flat, 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, which 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. 68.~Toothof (?Ii(p. 
todoih from the side, and 
from the grinding surface. 
(After Owen.) 



GL YP TODONTID^ 



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. Panochthus com- 
prises very large Glyptodonts, 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. Eurifurus is distinguished by the radiate 
sculpture of the scutes of the carapace. Dcedicnnis, 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-Kke shape, flattened from above downwards. 




Fig. i?9.—GIyptodonclavipes (Pleistocene, South America). From Owen. The tail is incorrectly 
restored, and it is probable that the figured portion belongs to Eoplophorus. 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 irith a few large radiate discs, 
which, as in Panodifhu-i, probably carried horny spines in the li^-ing 
condition. The typical genus Gly/itod&n has each scute of the 
carapace ornamented with a rosette-like sculpture, the peripheral 
scutes being raised into conical prominences (Fig. 69). The caudal 
sheath, instead of being like the one represented in the figiu-e, was 
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 
tj-pe of Sdmtopleunim, on the supposition that the tail of Ghjptoikia 
was of the type represented in Fig. 69. The genus Tlv/mcophirus, 



204 EDENTATA 



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. G-lyptodonts 
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 Glyptodon 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 Eome vt^as built, for eternity." 



Family Manid^. 

Covered externally (except the under surface of the body and 
inside of the limbs) with large imbricated homy scales, and 
scattered hairs grooving 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 semicyHndri- 
cal surfaces of the posterior zygapophyses. Limbs short, Avith 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 foUowine 
family differ from all the preceding forms. 

Manis} — Skull somewhat of the form of an elongated cone, -vrith 
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, ovidng to the absence of 
the jugal bone. No distinct lachrymal bone. Palate long and 
narrow. The pterygoids extend backwards as far as the tjTnpanics, 
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, vnthout 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 thii-d 
trochanter to the femur. Ungual phalanges bifid at their ter- 
minations. Caudal vertebraa 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 lininw 
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). 



MANID^ 205 



secreting follicles, the ducts of which terminate in a common 
orifice. No caecum. 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 siirface 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 stiff 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 ^^•ith 
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 Manis 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 truly 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, without 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 



EDENTA TA 



as an organ of touch. There are three species, viz. Munis javanica, 
ranging from Burma, through Malacca and Java, to Borneo ; M. 
auritii, found in China, Formosa, and Nipal ; and the common Indian 
Pangolin, 31. 'pentadackjla, 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 
group : — the 
Long-tailed Pan- 
golin {M. 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 kno-mi 
among mammals ; 
the AATiite-bellied 
Pangolin (J/, fri- 
cusjjis), Fig. 70, 
closely allied to 
the last, but -n-ith 
longer and tri- 
cuspid scales, and 
white belly hairs. 
These two, like 
the Indian species, have a naked spot beneath the tail tip, a chai-- 
acter probably correlated -^vith the power of climbing, and thev 
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 (J/. 
kmmindd and gigantea), both of which have theii' 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, 71/. femmindi, extending also into south 
and eastern equatorial Africa. 

According to Professor AV. K. Parker,i 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 

^ Mammalian Descent, p. 95. 




Fig. 70.— The Wliite-bellied Pangolin (Manis tricusjn.^). 



MANID^ 207 



its body, with lines of thinner cuticle between. Under the micro- 
scope, sections of these thicker tracts show that they are composed 
of fine 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^ that there are occasional in- 
stances of the presence of eight cervical vertebrae 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 Manis trkuspis 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." 

^ Mammalian 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. 

Eemains of a large species of Manis, which are indistinguishable 
from the corresponding bones of the existing West African M. 
gigantea, 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 with 
the existing African fauna. 

Palceomanis} — 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 siurface 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 poUex, but all 
the other digits well developed, with 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. 

Oryderopus} — 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 below, 
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 havino- no 
milk-predecessors, may be regarded as true molars. The structure 
of all these teeth is quite peculiar among mammals, though 
resemblmg 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 up of an 
aggregation of parallel dental sygtems, having a slender pulp-cavity 

' Forsyth-Major, Comptes Mcndus, vol. evii. p. 1180 (1888). 
^ Geoffrey, Dicacle PMlosophique, 1795 (teste Agassiz). 



ORYCTEROPODID^ 2oq 

in the centre, from wMcli 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 subcyhndrical 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 reciirved 
coronoid, and an ascending pointed process on the hinder edge 
below the condyle, which is small, oval, and looks as much forwards 
as upwards. Vertebraj : C 7, D 13, L 8, S 6, C 27. The large 
number of lumbar vertebrae is peculiar among Edentates. Tongue 
less vermiform than in Myrmecopluiga, being thick and fleshy at the 
base, and gradually tapering to the apex. The saHvary 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 caecum ; 
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 Oryderopus 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 Eodents. The 
placenta is broadly zonary, but it is not known whether it is 
deciduate or not. It might readily be derived from the diffased 
placenta of Manis by the abortion of the foetal viUi at the two poles 
of the ovum. 

The Ori/deropodidcc have long been regarded as widely different 
from other Edentates, their presumed aflSnity with the Manidce 
being more or less problematical ; but the discovery recently made 
by Mr. 0. Thomas ^ that they have a milk-dentition stiU fiu-ther 
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, 
^ Proceedings of the Royal Society, vol. xlvii. p. 246 (1890). 
14 



EDENTA TA 



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 hy equal 
intervals; the foremost of all is situated immediately behind the 
premaxillo-maxiUary suture. In the mandible only four mUk-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 which 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 questions 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. Xow, 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 TubuHdentata, 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, we 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 pateontological 
knowledge of the extinct allies of either. Macrotherium 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 3Ianis, or Oryderopus were to be sought in that 
direction. Lastly, as the numerous fossil American Edentates do 



OR YCTEROPODID^ 2 1 1 

not slio-nr 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 phylogeny 
must therefore for the present remain one of the many unsolved 
zoological problems." 

The Aard-Varks (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. 

Two 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, difiering from the exist- 
ing forms by the larger proportionate size of the lateral meta- 
tarsals. 

Bibliography of Edentata. — Jv'o general work on the order has heen published 
since that of Rapp (Anat. Untersuchu'jigen ilher die Edeiitaten, 2d ed. 1852). 
Among nmnerous memoirs on special groups the following may be cited : — 
MyrmecopAagidce : — R. Owen, "Anatomy of Great Anteater," Trans. Zool. Soc. 
vol. iv. ; G. Pouchet, Mim. sur le G'rand Fourmilier, 1874 ; W. A. Forbes, 
"Anat. of Great Anteater," Proc. Zool. Soc. 1882, p. 287. Megatheriidte : — R. 
Owen, Extinct Gigantic Sloth {Mylodon Bobustus), 1842; Id., "On the Mega- 
therium," Phil. Trans. 1851-56; J. Leidy, "Extinct Sloth -tribe of North 
America," Smithsonian Contrib. to Krwwledge, vii. 1855 ; H. Burmeister, 
Description de la Eipublique Argentine, t. iii. llammiferes, 1879, — which contains 
fuU references to various memoirs by Owen, Gervais, Reiahardt, and others. 
Glyptodontidce : — Owen, Catalogue of Fossil Mammals, Mus. Boy. Coll. Surgeons, 
1845 ; T. H. Huxley, "Osteol. of Gljptodon," Phil. Trans. 1865 ; H. Burmeister, 
Aniiales del Museo Publico de Buenos Aires, and Bescript. de la Eipublique 
Argentina, 1879 ; H. Gervais and F. Ameghino, Les Mammifires Fossiles de 
VAmirique Miridionale, Paris, 1880, — which also contains a list of all the 
S. American Edentates described at that date. Basypodidoe : — J. Jlurie, "Ana- 
tomy of Tolypeutes," Trans. Linn. Soc. vol. xxx. 1874 ; A. H. Garrod, Proc. 
Zool. Soc. 1878. For Placentation of Edentates see W. Turner, Trails. Boy. Soc. 
Edin. xxvii. (1873) p. 72, and Journ. Anat. and Physiol, vols. viii. and x. ; A. 
MUne-Edwards, Ann. Sciences Nat. [6] viii. p. 1 ; and for brain, P. Gervais, 
"Formes cerebrales des Edentes," Nouv. Arch, du Museum, torn. v. ; W. Turner, 
Jour. Anatomy, i. 313 (1867). For the dentition of Oryderojms 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 Afianities of the Animals composing the Order 
Edentata," Proc. Zool. Soc. 1882, p. 358. 



CHAPTEE Ylll 

THE ORDEES SEREXIA A^T> CETACEA 

Order Sieexia. 

The purely aquatic halnts and fish-like form of the animals of this 
order caused them to be formerly confounded -svirh the Cetacea, 
hut 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 which it is soaicely separated by any 
externally visible consti-ietion or neck. Xosti-ils Talvular, 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 Hps beset with stiff bristles. Genei-al form of the body 
depressed, fusifoim. Xo dorsal fin. Tail flattened and horizontally 
expanded. Eore limbs paddle-shaped, the digits being enveloped 
in a common cutaneous covering, on which rudiments of nails are 
sometimes present. Xo trace of hind limbs in existing forms. Ex- 
ternal surface covered Tvith a tough, finely wrinkled, or verv 
rugose skin, naked, or with fine haii-s sparsely scattered over it. 

The skeleton is remarkable for the massiveness and densitv 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-movino- 
animals, and aid in keeping them to the bottom of the shallow 
waters in which they dwell, whUe feeding on aquatic veiietables. 
The skuU 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 amons Ungu- 
lates, and presenting some approach to that so characteristic of the 
Cetacea. The nasal bones are generally absent in the recent forms 



SI RENT A 213 



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 disc-like epiphyses in the young state, as 
in nearly all other mammals ; traces of epiphyses have, however, 
been recently detected in Manatiis, and they were fully developed in 
Halitherium and other fossil forms. The anterior caudal vertebrae 
have well-developed chevron bones. In one genus (Mmuitus) there 
are only six cervical vertebrae. 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 Halitherium 
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 (Rhytina) 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, caecal sacs or diverticula. The intestinal canal is long, and 
has very muscular walls. There is a CEecum, either simple, conical, 
and with extremely thick walls, 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 SIREXIA 



owing to the very oblique position of the diaphragm, the thoracic 
carity extends far back over the abdomen. The epiglottis and 
arytenoid cartilages of the larynx do not form a tabular 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 bicomuate. The 
placenta (in the Diigc>ng) is non-deciduate and zonary. The um- 
bilical vesicle disappears early. The mamuMe are two, and pectoral, 
or rather post-axillary in position. 

The Sirenia pass their whole 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 alga? or 
freshwater grasses, upon which they browse beneath the surface, as 
the terrestrial herbivorous mammals do upon the gTeen 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 Du^ong 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 earlv 
voyagers in the Indian Ocean, to the legendary beings, half human 
and half fish, in allusion to which the name Sirenia was bestowed bv 
Miger on the order, though certainly the face of a Dugong. when 
closely inspected, does not bear the slightest resemblance tothat of 
the mermaid of romance. The species now existing are verv few 
and there is reason to believe that the time is not far distant" when 
they will all become extinct. One species, Bhytina stdleri, of the 
Xorth Pacific, was totally exterminated through the agencv of man 
during the last centiuy; 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 diminis h in numbers as civilised populations occupy the 
regions forming their natiu^l habitat. The siu-viving 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 Eed Sea to 
2sorth AustraUa. 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 Xorth 
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 nummuEtic limestone moimtain ranges of Eirvpt were 
deposited. ^ ^' 



MAN A TID^ 



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^. 

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. 

ManatusJ — Incisors f, rudimentary, concealed beneath the horny 
oral plates, and disappearing before maturity. Molars ^j-, but 
rarely more than -f- 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 vertebrae present the remarkable anomaly of being reduced to 
six in number, the usual vertebral formula being C 6, D 1 7, 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 ; premaxillse 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 Maimti 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 ivill be treated of further on, but it -^vill be chiefly to the 
latter and better known form that the following description applies. 

The size of the Manatee has been much exaggerated, but 

^ Storr, Prodromics Meth. Mamvi. p. 41 (1780). 



SIREXJA 



there is no trustworthy cAadence 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-bke, 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 di^aded from the body by a ver}' slight constriction or neck. 
The fore hmbs are flattened oval paddles, placed rather low on the 
sides of the body, and showing externally no signs of di-^-ision into 
fingers, but with a tolerably free motion at the shoulder, elbow, 
and wrist joints, and with three diminutive flat nails near their 
extremities. Xo 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 Hne 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 




5l> 

Fig. 71. — American Manatee Qlanatus americanus), from life. Froc. Zool. Soc, liSl. p. 457. 

valve-like shts, at the apex of the muzzle. The eves are verv 
minute, placed at the sides of the head, and -nith 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 ^vrinkled. At a httle distance 
it appears naked, but a close inspection, at all events in voung 
animals, shows a scanty covering of very delicate hairs, and' both 
upper and under lips are well supplied mth short stiff liristles. 

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 larc^e 
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 



MANAT1D.-E 



217 



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 premaxillse, 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 




Fig. 72. — Skull of African Manatee (Manatus senegalensis). } 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 
jolates, 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, ^-nnr o^ '^^ 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. Dii'ectly 
the leaf is within grasp the lip-pads are approximated, the leaf is 
firmly seized between their contiguous bristly surfaces, and then 



MANATID^ 219 



dra"5ra inwards by a backward movement of the lower margin of 
the lip as a whole." The animal is thus enabled by the unaided 
means of the upper lip to introduce food placed before it without 
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 iUirie, 
Trans. Zool. Soc. vol. xi. 

or in captivity, indicate that it has not the jDOwer 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 ■' 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. Jahrhuch, vol. i. p. 1 (1886). 



SIREXIA 



bones. Of these the American Manatee may be known as J/. 
amerieanuf, although it has been described under the names of 
M. latiivsiri^. and J/. ati<froJi<. The African Manatee {if. senegaleruis) 
differs from the American sijecies in the following cranial characters : 
the anterior pait of the rostrum is shorter, shallower, and altogether 
smaller ; the orbit is smaller : the zTgomatic 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 Sat. 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. J/, inungu'ti is a fluviatile species confined to the 
Amivzon and Orinoco, which has been but recently fully brought 
tmder the notice of zoolodsts. 



FamUy Hat .tcqeidj. 

Haliojiv.^ — In the upper jaw a pair of large, nearly straight, tusk- 
like incisors, directed downwards and fonrards. partially coated 
with enamel In the male they have persistent pulps, and bevelled 
cutting edges, which project a short dist;mce from the mouth, but 
in the female, though they remain through life in the alveolar 
cavity, they are not exseited, and, the pulp-cavity being filled with 
osteodentine. they soon cease to grow (as in the female Xarwhal). 
In the young there is also a second small deciduous incisor on 
each side above. At this age there are also beneath the homy 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 matruity. The molars 
are tisuaUy f . sometimes 4: altogether, but not all in place at once, 
as the iirst falls before the last rises above the gum : thev are more 
or less nearly cylindrical in section (except the" last, which is com- 
pressed and grooved laterally), vithout 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. SkuU with rostrum 
formed by the union of the premasdUse 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 conesponding manner. Tertebne : C 7. D 1^^-19 L and 
C30. Tail broadly notched in the middle Hue, and with two 
pointed lateral lobes, ^o naUs on the fore limbs. Ciecum sinde. 

- i::: -er. Pn'^IrMms S^'^t. M:'um. c'. Ani:m, p. 140 ;ii:i). 



RHYTINID^ 17.1 

The Dugongs are more distinctly marine in their habits than the 
Manatees, feeding chiefly on sea -water algae. 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. tabernaculi 
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, which 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^s:. 

Rhytina?- — 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. Vertebrae : C 7, D 19, Land 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. Caecum 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 
ivrecked upon it in 1741. Twenty-seven years afterwards (1768), 
as is commonly supposed, the last of the race was killed,^ and its 

1 Illiger, Prodromus Syst. Mamm. et Avium, p. 141 (1811). — Amended from 
Bytina. 

^ Nordenskiold, 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 1864 ; but this conclusion 
is disputed by later writers. 



SIREIVIA 



very existence would have been unknoTrn to science but for the 
interesting account of its anatomy and habits left by SteUer, 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 
alwavs so restricted. When first discovered it was extremely 
numerous in the shallow bays round Behring Island, finding 
abundant nutriment in the large lam in arise growing in the sea. 
Its extirpation is entirely due to the Eussian hunters and traders 
who followed upon the track of the explorers, and, upon SteUer'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 SteUer's account, the Ehytina had a skin of a dark 
brown colour, sometimes spotted or streaked with white. The fore 
limb was covered with short brush-Kke hairs. 



Extinct Sikeniaxs. 

Salitherium,} — The ^Miocene and early Pliocene seas of Europe 
abounded in Sirenians, to which the generic name of HaUtherium 
was given by Kaup, but which have also received other names. 
They had large tusk-like iacisors ia the upper jaw, as in the 
existing Dugongs, though not so greatly developed. Their molar 
teeth were f or f, anteriorly simple and single-rooted, posteriorly 
those above with three and those below Avith 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 mi l k -teeth. Germs of inferior incisors were also 
present. Some species at least had nasal bones, short, broad, 
but normal ia position, whereas in all the existing genera these 
bones are quite rudimentary. Another and still more important 
e^^dence of conformity to the general mammalian tj^e is the 
better development of the pehac bone, and the presence of a small 
styliform femui- articulated to the acetabulum, although no traces 
of any other part of the Hmb have been discovered. These ancient 
Sirenians, which may be regarded as representing a distinct family 
— EaJitlieriidcE — were thus, in dental, cranial, and other osteolooical 
characters, less specialised than are either of the existing species 

1 Kaup, Xcxits JahrbucJi, 1S3S, pp. 319 and 536. 



HALITHERIID^ 



223 




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 west 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 Fio. 74.— The penultimate and last right lower molars 
a skull and several ^^ Halitherium fossile ; from the Miocene of the Continent. 
, , , -, , T j_ i T (After De Blainville.) 

teeth have been detected 

among the rolled debris of which the Eed 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. — Eemains from the Pliocene of France described as 
Frohalicore 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 Halicm'e with Halitherium, but even 
its ordinal position is uncertain. 

A portion of a skull found in the Pliocene of Belgium has been 
described as C'rassitherium 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 Trachytherimn of the French 
Miocene, better preserved remains have subsequently been described 
by Delfortrie. These show that the rostrum is more elongated 
than in Halitherium, 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. 

Pachyacanthus 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 [Jnited 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 Halitherium, the dentition being apparently i %, c \, 

p + m f ^ j = 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 Prorastomus sirenoides. Some 
writers regard this genus as the type of a distinct family — the 
Prorastomatidce. Unfortunately we have no knowledge of the geo- 
logical antiquity of the formation in which it was embedded. Lastly 
must be mentioned the Eotherium egyptiacum, 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 Manatus, 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 then- 
association with 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, Symbolm Sirenologiccc, 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 Rhytina. 



CETACEA 225 



Anatomy of Dugong : — Everard Home, Phil. Trans. 1820, p. 315; Owen, Froc. 
Zool. Soc. 1838, p. 29. Placenta of do.:~yf. Turner, Trans. Roy. Soc. Edin. 
vol. xxxT. (1889). Manatee: — AV. Vrolik, Bijdragen tot de DierTcwnde, 1851; 
J. Murie, "On the Form and Structure of tlie Manatee," Trans. Zool. Soc. Land. 
vol. viii. p. 127, 1872, and "Further Obseryations on the Manatee," Ibid. vol. 
xi. p. 19, 1880 ; A. H. Garrod, " Notes on the Manatee recently living in the 
Zoological Society's Gardens," Ibid. vol. x. p. 137, 1875 ; H. C. Chapman, 
"Observations on the Structure of the Manatee," Proc. Acad. Nat. Sciences of 
Philadelphia, 1875, 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 de Zoologie, torn. i. p. 332, 1872. E. 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 Avhich 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 off 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 



226 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 vertebrae, 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. Xone 
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.^ 
There are largely developed chevron bones, the presence of which 
indicates the distinction between the caudal and lumbar vertebrae. 

The skull jJFig. 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, 
premaxillae, 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 imperfect, the flattened ends of the bones coming in 
contact with 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.^ 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 Tliis 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 existing 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 laminae or "baleen." 
The salivary glands are rudimentary or absent. The stomach is 
multilocular, its structure being fully noticed under the genus 



jva 



Fr 




BxO 



Fio. 76.— A section of the skull of a young Dolphin (GloUceplialus mdos). X J. PMx, Pre- 
maxiUa ; Mx, maxilla ; ME, ossified portion of the mesethmoid ; an, anterior nares ; Na, 
nasal ; IP, Inter-parietal ; Fr, frontal ; Pa, parietal ; SO, supraoccipital ; ExO, exoccipital . 
BO, basioccipital ; Sq, squamosal ; Per, periotic ; AS, alisphenoid ; PS, presphenoid ; Ft, 
pterygoid ; pn, 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 ; 
Ih, basi-hyal ; th, thyro-hyal. (From Flower's Osteology of Mammalia.) 

PJwccena. The intestinal canal is simple, and only in some species 
provided with a small cajcum. The liver is very little fissured, and 
there is no gall-bladder. The vascular system is greatly complicated 
by arterial and venous plexuses, or retia mimbilia. The larynx is of 
peculiar shape, the arytenoid cartilages and the epiglottis being 
inuch 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 
tirachea, 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 lobulatei The 
testes are abdominal. There are no vesiculae seminales, nor os 
penis. The uterus is bicornuate, and the placenta nondeciduate 
and diifase. 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 water 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 frequently 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 stUl 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 
consequence 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 pierces the lungs or air passage's 
of the unfortunate victim, and then fountains of blood may bej 
forced high in the air through the blowholes, as commonly depicted 



GENERAL CHARACTERS 229 

in scenes of Arctic 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 predaceous, 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 Tmthidce, 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 we have any 
cei'tain ei'idence. "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, swimmiag 
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 ^ATiale is a fish. To reaKse 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 



230 CETACEA 

reptiles, birds, and mammals, the ^ATiale resembles the last-named 
and diiFers 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 commion 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 suit€d for 
sw im ming 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 water, is reduced to the merest rudiments — a 
few short bristles about the chin or upper Hp — 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 foimd 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 "\ATiales 
or Odontoceti and the Baleen "\'\Tiales 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,^ 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 
difierent fashions from common ancestors. 

. Among the Mystacocetes, in the especially distinguishing 
characters of the division, the Eorquals 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 Eorquals {Cetotlwium) 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 gTcater 
length of the cervical vertebrte, 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 Flatanisia, 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 type, 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, 
with 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,^ 
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 with the primitive forms of many other 
types. The forward position of the narial aperture and the length 
and flatness of the nasal bones, which distinguish them from all 
existing forms, we must also suppose to be a character at one time 
common to all Cetaceans, though now retained (but to a less degree) 
only by the Mystacocetes. Even Squalodon, which 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 with the ordinary Dolphins in its essential cranial 
characters. 

The origin of the Cetacea is at present involved in much ob- 
scurity. They present no signs of closer affinity to any of the 
lower classes of vertebrates than do many other members of their 
own class. Indeed in all that essentially distinguishes a mammal 
from the oviparous vertebrates, whether 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 which the heterodont type of dentition was fully 

1 The ankylosed mass of cervical vertebraj, on whicli the genus Palceocetiis 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 Otariidce 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 aquatic 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 {Lictra 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 Zeuglodon, 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,^ 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 " ^ 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, 

' There is much resemblance in the larynx of the Hippopotamus, but none 
in that of the Seal, to the same organ in the Cetacea. 

- German Meerschwein, whence the French Marsouin. "Porpoise" is said 
to be derived from " Pwc-poisson." 



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. 

Subcyfder Mystacoceti, 
the Baljenoidea, Whalebone, or True JVTiales} 

Family Balenid^. 

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 vertebrae ; their capitular 
processes, when present, not articulating directly with the bodies of 
the vertebrfe. 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, when in the foetal state, numerous minute 
calcified teeth lying in the dental groove of both upper and lower 
jaws. They are best developed about the middle of foetal life, after 
which period they are absorbed, and no trace of them remains at the 
time of birth.2 The baleen or whalebone 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 Svved. hval ; Anglo-Saxon hwccl ; Germ, wal, 
lualfisA. The meaning apparently is "roller," the word bein" closely allied to 
"wheel" (Skeat). 

= These were discovered in the Greenland "Whale hy Geoffrey St. Hilaire, 
whose observations were confirmed and extended to other genera by Esohricht! 
They have been very fully described in Bakcnoptera rostrata by Julin (Archiv's 
dc Biologic, i. 18S0). 



BAL^NID^ 235 

the palate, with a bare interval along the middle line. These plates 
are placed transversely to the long axis of the palate, Avith very short 
intervals between them. Each plate or blade is somewhat triangular 
in form, with the base attached to the palate and the apex hanging 
downwards. 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 maxillse, 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 papillae, 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 papillfe, 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 hair-like 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 Ehinoceros. The whalebone in fact consists of nothing 
more than modified papillae 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 diiTerent 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 



236 CETACEA 



whalebone blades, and escapes through the lips, leaving the living 
prey to be swallowed. ^ 

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 Eight Whales (Balcena) and Eorquals or Fin- Whales 
{Balcenoptera), the latter distinguished by their smaller heads, 
elongated and slender form, free cervical vertebrae, tetradactylous 
manus, 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.^ — Skin of throat smooth, not furrowed. No dorsal fin. 
Cervical vertebrae united into a single mass. Pectoral limb short, 
. broad, and pentadactylous. 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 ivithout a well-marked depression at the 
anterior extremity of the superior border of the inner surface for 
the Eustachian canal. 




Fia. 76. —Greenland or Arctic Kiglit Whale (Balcena mysticctus) 



The Greenland, or more properly Arctic, Eight Whale (Balcena 
imjstketus) 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 atructuro of whalebone see Hunter, "Observations on the Structure 
and Economy of Whales," Phil. Trans. 1787 ; Eschricht and Reinhardt, On the 
Oreenland Eight Whale, English translation by the Ray Society, 1866, pp. 67-78 ; 
and Sir W. Turner, in Trans. Boy. Soc. Edin. 1870. 

^ Linn. Syst. Nat. 12th ed. vol. i. p. 105 (1766). 



BALJENID^ 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 sufl5cient 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 when the jaws were 
separated, through which the water and the minute particles of food 
would escape together. But instead of this the long, slender, 
brush-like, 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 lower 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, '\\'here a cold stream 
sets down from the north, its range is somewhat fai'ther. In the 
Behring Sea, according to Scammon, " it is seldom seen south of 
the iifty-fifth parallel, which is about the farthest southern extent 
of the winter ice, while on the Sea of Okhotsk its southern limit is 
about the latitude of 54°." As has been abundantly shown by 
Eschricht and Reinhardt in the case of the Greenland seas, " every- 
thing tends to prove," Scammon says, " that the Ikila'ita iiii/sfmiiis 
is truly an ' ice whale,' 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 A\-here winter ice-fields are occasionallj^ met 
with." The occurrence of this species, therefore, on the British or 
any European coast is exceedingly unlikely, as when ali\'e 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 04° N. lat. 
along the north of Iceland towards Spitzbergen, and a glance at a 
phj'sical chart will show that there are no ciu-reTits setting south- 
wards which could bear a disabled animal or a floating carcase to 
British shores. To this A yriori 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 Eight Whale 
doins; the same. 




Fia. 77.— Southern Right Whale (nuhnm imslyalis). 



The southern Right ■W^ia.lc {B. aiis/mli,, 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 diflercnt shaped 
contour of the upper margin of the loM-er lip, and a greater number 



bal^nida: 239 

(fifteen) of ribs and dorsal vertebras. 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 : — B. biscayensis of the North Atlantic, £. japonica of 
the North Pacific, B. australis of the South Atlantic, and B. anti- 
podarum and B. novm-zealandi(B of the South Pacific. The diiFerential 
characters by which they have been separated, external as vs^ell as 
anatomical, are, however, slight and subject to individual variation ; 
and the number of specimens available for comparison in museums 
is not yet sufiicient 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 Eight 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 Whale " 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 Eight 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 Eeinhardt 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 



CETACEA 



of the United States several Whales of this species have been taken 
"\vithin 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, Eight Whales are never or rarely seen ; but 
the southern temperate ocean, especially the neighboitthood of the 
Cape of Good Hope, Kerguelen's Island, Australia, and New Zea- 
land, is inhabited by "Black ^Vhales," once abundant, but now 
nearly exterminated through the wanton destruction of the females 
as they %'isit the bays and inlets round the coast, their constant 
habit in the breeding time. The range of these "\Miales southward 
has not been accurately determined ; but no species corresponding 
mth the Arctic Eight Whale has as yet been met with in the 
Antarctic icy seas. 






Fig. 7S.— The riglit tympanic bone of an immatm-e indiridual of the Greenland Whale 
iBakciM mysticetus), from the inner (,A) and onter (B) aspects. } natural size fFrom the 
Proc. Zool. Soc.) 

Eemains of Eight A^Tiales are of not uncommon occuiTence 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. mysticdus, in which this bone is long and anonlated 
anteriorly (Fig. 78); while the tympanies from the same deposits 
described as B. primigenia are shorter and more rounded at the 
antero- inferior angle, thus resembling those of B. ausfralis. A 
smaller species, having an estimated length of about 20 feet, has 
been described as Balcenula balcenopsis, the generic distinction bein^ 
made on account of the free condition of the atlas and seventh 
cervical vertebra ; but it seems scarcely ad^^sable to regard such a 
feature as indicating more than a less specialised species. Balcem 
(Bdhviwtii^) iusifjim is a whale of somewhat larger dimensions, in 
which the atlas is generally, and the seventh cervical vertebra 




BAL^NID^ 241 

always, free, while in young individuals the axis vertebra may 
likewise be separate. 

Neobalcena.^ — Head about one-fourtb the total length. Skin of 
the throat not plicated. A small falcate dorsal fin. Vertebrae, 
C 7, D 17, L 3, C 16 = 43 The cervical vertebrae are united. The 
manus small, narrow, and tetradactylous, wanting the poUex. 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, iV. nmr- 
ginata, from the Australian and New Zealand seas is the smallest 
of the Whalebone Whales, being not more than 20 feet in length. 

Rliachianedes} — 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 BalcBna. The baleen is the 
shortest and coarsest of any of the group. Its osteology is im- 
perfectly known. One species, B. glaums, the Gray Whale of the 
North Pacific. 

Megaptera.^ — Head of moderate size. Baleen plates short and 
broad. Vertebra, C 7, D 14, L 11, C 21 =53. Cervical vertebras 
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, -n-ith 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 loops) 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 Graj', Supi>l. Cat. Seals and Whales in Brit. Mus. p. 39 (1871). 

2 Cope, Proc. Ac. Kat. Sci. PMlad. 1869, p. 15. 

= Gray, Zoology of ErAus and Terror, p. 16 (1846). 

16 



i-lr 



w>i: 










:- 5e:":r5 01 5"^:>eciinen5 of liiaerent ages anci sfxes 

s ^c55 cji:i!:i;r„~ ::i:.:i mose oi £::.jKd and i^'j.'.rn- 

r _. TiV. .■ ::icT :i:;ve r>eeii deso-ril-ed under the 

i names of JiVjjf>;T_7^fi> and £u:iin-:\'Sii. 

~ i?-:'.T;;;_;"-::'L;.- — Head jmall and fa:, and 

I :;cap\a.a .;— ana ■;r:ad. -witri a large acr^jnnon 
V ana eora; ::a 2:r;cfif. Pectoral lim":. :em\aac:v- 

_ -t-j-- -- -.ng. n:a'-n innatra. an'a rounaoa. wiiii 
~. :ar :a.v;.a:ra v;rn. :n tnaLKenea and pyi-iform. 
i: ana :ne no:-:n irr :ne Ensraoidan canal iharplv 

denned ; inner svnnaoe dartened. Trithoiit the 

vertical croove found in J/-.;n:'- ■- 

The Eorouah. Fin-^^il^s. Fin-sackf. Fm^ 

ner;. or Eaain'/^aoks. a; they are varionslv called. 



= La-;rr.eie. 



■Oa tl:; Aait:a:y cf 3I-:jjy.t^r^ 



BALMNID^ 



243 




have the plicated skin of the throat like that of Megaptera, 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 difiiculty 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) Balanoptera sib- 
haldi, 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 
vertebra}, of which 16 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 Balcenoptera musculus from 
the inner (A) and outer (B) aspects, i 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) 
Balcenoptera 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, lightcoloured spots, whilst 
the under parts are more or less white ; the whole of the taU 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 vertebrae, with 14 pairs of ribs. This species, according to 
Collett, feeds chiefly on minute crustaceans, mainly Calanus finmar- 
chicus and Buphausia 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 rostrata, the 
lesser Fin- Whale or Eorqual, 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, 11 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. 

Eorquals 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 



BALJENIDyE 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.^ 

Tympanies, vertebrae, 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. clefinita (sibbaldina) being apparently 
nearly related to the existing B. sibbaldi. A caudal vertebra from 
the Upper Eocene of Hampshire has been referred to Balcenoptera, but 
does not afford sufficient evidence to prove the existence of the 
genus at that date. 

Extinct Genera. — The extinct genus Cetotherium of the European 
Pliocene may be taken to include a number of fossil Whalebone 
Whales allied to the Balsenopterine 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 
Balcenoptera. 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 
vertebras is also greater. In the typical forms {e.g. C. hrialmonti 
and C. duUum) the mandibular condyle is simple ; but in C. 
{Heterocetm) hrevifrons it is furnished with a projecting posterior 
talon, as in the Sperm Whale. 

Eerpetocetus 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. 

Palceocetus, as- already mentioned (p. 232), is founded upon the 
ankylosed cervical vertebrae 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 Bakenidci' it indi- 
cates a Eight Whale. 

1 See P. J. "Van Beneden, "Histoire Naturelles des Balenopteres, " M6m. Acad. 
Belgiqite, xli. 1887. 



246 CETACEA 

Suborder Arcileoceti. 

Family ZETJGLODONTIDiE. 

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.'- 

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 « -|, c \, p and m -f = 36, resembling that 
of some Seals.^ 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, difiering from 
that of other Cetaceans in the large extent to which the premaxUlae 
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 
vertebrae free. The characters of the dorsal vertebrae and mode of 
articulation of the ribs appear to have resembled those of Platanista 
rather than Balcena, Physeter, or Delphinus. Lumbar vertebrae 
with elongated bodies, low neural spines, and the transverse pro- 
cesses placed low down on the bodies. Characters of the limbs 
not known with certainty.^ 

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'Arcy Thompson lias brouglit forward some 
arguments to show that the Zeuglodonts have no direct affinities with the Cetacea, 
but have on the other hand the strongest possible relation with the Pinnipede 
Garni vora. "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. 

^ A mutilated humerus of Zeuglodon cetoides 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 ti-uly Cetacean. 



PHYSETERIDM 247 

yoked together." This name was substituted by Owen for the 
earlier one Basilosaurus of Harlan, with the consent of that author, 
on the mammalian nature of the animal being demonstrated.^ 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 vertebrae. 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 vahoilar 
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 Physeterid^. 

No functional teeth in the upper jaw. Mandibular teeth various, 
often much reduced in number. Bones of the cranium raised so as 

^ See Trans. Geol. Soe. 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 vi^all 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 vertebrae, 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 Physeterinse. — 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.''- — Upper teeth apparently of uncertain number, rudi- 
mentary, and functionless, being embedded in the gum. Lower jaw 




Fia 



S2.— Skull of Spei'ill Whale (Physeter macrocepltalus). 



with from 20 to 2.5 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 edo-es 
raised into a very high and greatly compressed semicircular crest 
or wall. Zygomatic processes of jugal bones thick and massive. 
Eostrum greatly elongated, broad at the base, and gradually tapering 
' Linn. Syst. Nat. 12tli ed. vol. i. p. 107 (176C). 



PHYSETERID.-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 24 ; 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 smTounding 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 




:._The Sperm Whale (Fhyseter 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 fuU-gTOwn 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 which 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 



CETACEA 



floating on the surface of the seas it inhabits. Its genuineness is 
proved by the presence of the homy 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 niunbers have been greatly diminished. 

Cogw.} — 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 styUform. 
Mandible with the symphysis less than half the length of the entire 
ramus. Vertebrae : C 7, D 13 or 14, L and C 30 ; total 50 or 51. 
All the cervical vertebrae 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 BlainvUle under the name of Physekr bremejjs. 
This was afterwards with good reason generically separated by Gray. 
Until within a very few years ago only five other individuals had 
been met with, eaph of which had been described under a different 
specific name (^-iz. graiji, macJeat/i, simus, flmcen, 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 difierences 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. In-ei-keps. This 
animal appears to attain the length of 10 feet when adult, and has 
1 Gray, Zoology of F rebus and Terror, p. 22 US46). UsuaUy spelt Kogia. 



PHYSE TERID^ 2 5 1 

been met with at various distant localities in the Southern Ocean, 
and also off 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 eases 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 {Dinoziphius) 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 Hoplocetus. The genus Balcenodon 
is founded upon a very imperfect large tooth from the English Crag, 
which is not suflaciently 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 Delphinidm. 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. 

Hypewodon} — A small conical pointed tooth at the apex of each 
ramixs of the mandible, concealed by the gum during life. Skull 
with the upper ends of the premaxillse 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 premaxiUEe, 
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 
maxillae 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 bixt slightly ossified. 
Vertebrae: C 7, D 9, L 10, C 19 ; total 45. All the cer-sacal 
vertebrae united. Upper surface of the head in front of the blow- 




FlG. Si.— Hyperoddon rostmtus. From a female specunen taken off the coast of Scotland, 18S-2. 

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. pkmifrons — 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.^ So different, indeed, is the appearance of 
the skull of an old male from that of a female individual that 

1 Lacepede, "Table des Ordres," Hist. Xaf. dcs Citacis, p. xliv. (1804). 
- See the figures in the Proc. Zool. Soc. 1S82, pp. 728, 729. 



PHYSETERID.'E 253 



it Tras long considered that they belonged to different species — 
the male form having been described as H. kitifrons. The length 
of an adult male reaches 30 feet, while that of the female does not 
exceed 2 J: feet. 

The Hj'peroodon, sometimes called " Bottlenose," a name also 
vaguely given to several species of Dolphin, is a regular inhabitant 
of the Xorth 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-oU, this AATiale 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 
untU 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 ia 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° X. lat., and down the east side 
round Cape Farewell, aU round Iceland, north along the Greenland 
ice to 77° K". lat. ; also along the west coast of Spitzbergen, 
and east to Cherry Island in lat. 72^ X. and long. 19° E. Beyond 
these Hmits 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 fom- 
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, untU their cm-iosity 
is satisfied. . . . They vary in colom- from black in the young to 
light bro'mi 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 beUy. 
They can leap many feet out of the water, even having time while 



254 CETACEA 



in the aii- to tiu-n round their heads and look about them, taking 
the -(vater head tiist, and not falling helplessly into it sidewiiys like 
the larirer ^vhales. The fnll-arcmi whale is 30 feet loni:; bv ilO 
feet in cii'cumference, and yields two tons of oil besides two hiuidred- 
weight of spermaceti. . . . Then- ordinary food consists of a bliiish- 
white cuttle-fish, sis inches long by three inches in ciicimiference, 
and pointed towards the tail. . . . They evidently ha\"e a great 
depth to go to find them, judging from the length of time that 
they remain away, and from the long hea^•y blasts they make on 
coming to the siu-face again." 

Periotic bones of Hi/jkroodon are found in the Eed Crag of 
Suflblk, presenting no character by which they can be specifically 
distinguished from those of the common existing species. 

Zijphius.^-^A single conical tooth of moderate size on each side 
of the mandible close to the anterior extremity, and dii-ected 
forwards and upwards. Skidl with the premaxillre 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 
clU7^^ng forwards, the right being considerably more developed than 
the left ; the conjoint nasals forming a strongly pronounced s^tu- 
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 premaxillfe. Anteorbital notch not distinct. Eostrum (seen 
from above) triangular, gradually tapering fi-om the base to the 
apex : upper and outer edges of maxilla at base of rostntm i-aised 
into low roughened tuberosities. Mesethmoid cartilage densely 
ossified in adult age, and coalescing with the siu-roimding bones of 
the rostrum. Vertebni? : C 7, D 10, L 10, C 22 ; total "-19. The 
three anterior cer^•ical vertebra? imited, the rest free. 

The type of this genus is Z. cavirostrh of Cuvier, foiuided upon 
an imperfect skull picked up in 1804 on the Mediterranean coast 
of France, and described and figured in the 0^/cmens Fossihs under 
the impression that it was that of an extinct species. IMany other 
individuals have, however, been subsequently met with in various 
parts of the world, from the Shetland Islands to New Ze;iland, 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 Ptiimhi/iidiug and Epiodon 
being probably referable to the type species. 

It is quite probable that some of the Physoteroid teeth from the 
Crag deposits mentioned on p. 251 may be referable to ZipMus. 

Mesoplodon.- — A much compressed and pointed tooth in each 

^ Cuvier, Ossemcm Fossi/cs, 2d ed. vol. v. p. 352 (1823). 
2 Gervais, Ann. Sci. Xat. s6r. 3, vol. xiv. p. 16 (1S50). For the very com- 
plicated spionymy of this genus, see Tnvis. Zool. Soi: vol. viii. p. 20S. 



PHYSETERIDyE 255 



ramus of the mandible, variously situated, but generally at some 
distance behind the apex (Fig. 86) ; its point directed upwards, and 
often somewhat backwards, occasionally developed to a great size. 




Fio. So. — .Ut'50i)?0(?(i)i hiHtRS. From Reinhai'dt. 

Skull with the region around the nares as in Hyperoodon, except 
that the nasals are narrow and more sunk between the upper ends 
of the premaxillre ; like those of Hijpcroodon, they are concave in 
the middle line in front and above. Xo maxillary tuberosities. 
Anteorbital notch not very distinct. Eostrum long, narrow, and 
solid throuffhout. Mesethmoid in adult a2;e ossified in its entire 




Fu^. S(3. — Left Literal view of skull of Mc^oplodon densirostris. 

length, coalescing with the surrounding bones, and showing as a 
narrow band on the upper surface of the rostrum. Yertebraj : 
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 difterent 
members of this genus agree in their essential structm-e, 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 aijo ailvances, as seen most strikingly in the case of M. lai/ardi, 
where the long, narrow, flat, strap-like teeth, cvu-ving inwards at 
their extremities, actually meet over the rostrum, and must greatly 
interfere with the movements of the jaw. In one species (J/, iirai/i) 
a row of minute, conical, pointed teeth, like those of ordinai-y 
Dolphins, 1 7 to 1 9 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, 
with 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. hidens, M. europceus, M. densirostris, M. layardi, 
M. grayi, and M. hedori ; 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 
and water -worn fragments of 
animal remains which compose 
Fig. 87.-The left periotic bone of jifeso- the well-known "bone-bed" at 

plodon : from the Red Crag of Suffolk, The 4.1,1, £4.1, t>j/^ jrcij! 

smooth concave surface in the right upper ^^^ ^^Se of the Red Crag of Suf- 
corner of the figure forms the anterior ar- folk. Several Species have been 

ticuiation with the tympanic. (From the founded upon the evidence of 

Cat. Foss. Mamm. Brit. Mus. pt. v. p. 70.) , , , -r^ . , . t ,. 

these rostra. Feriotic 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} — 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 premaxillae 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. Eostrum 
long and narrow. Mesethmoid only partially ossified. Small 
rugous eminences on the outer edge of the upper surface of the 
maxillse 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. 

' Duvernoy, Ann. Sci. Nat.-Zoologie, ser. 3, vol. .\v. p. 4,1 (1S51). 



SQUALODOXTID.E 257 



ClwDci/tliiii^.^ — The rostral portions of crania from the Antwerp 
and Sufiolk Crags, on the evidence of which this genus has been 
established, agree with those of Mcaojtlodoii in having the premaxilte 
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, howeAer, in that 
the mesethmoid cartilage remains unossified, whereby a, tistular 
\'acuity remains. In some species the soldering of the inn«r 
surfaces of the premaxillas is incomplete. The interorbital region 
of the skull is flat ; and there ai-e two pits in the nasal region, of 
which the right is the larger. 



Fainilu Squalopontid-e. 

Numerous extinct forms, chiefly known by teeth and fragments 
of crania, may be provisionally placetl here, until more of their 
osteological characters shall be brought to light. They differ from 
all existing Cetaceans in ha^'ing the teeth distinctly difterentiated 
into groups, as in the Archa^oceti, 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. 

Siiiii(Iim!oh.- — All the forms may be included in this genus, the 
so-called liJii-.ojtnoii not being distinct. Dentition: ;' ^, c \, simple 
teeth of the molar series (premolars ?) -I-, two-rooted molars -f = t|-; 
total 60. The double-rooted molars difter from those of Zen<iloilon 
in having the denticulations of the crown confined to the posterior 
Jiortlor, or at all events much less developed on the front edge. 
^'ery 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 A'ionua basin, many parts 
of France, and the Antwerp and Suftblk Crags. They have also 
been found in formations of corresponding age in Xorth America 
and South Australia. A few isolated teeth have been met with in 
the ca\-e-deposits of Italv, which, if contemporaneous with the beds 
in ^^■hich they occur, indicate the sur'\'i^■al of the genus into the 
Pleistocene period. 

Familij Pl.-\taxistid.e. 

Under this heading may be placed three very singular genera, 
which, though diftering considerably from each other, have several 

^ Duverno}-, o^'. cit. p. 61. 
'- Grateloup, Act. Ac. J!. Sci. £oni<-aii.r, ISiO, p. 20S. 
17 



258 CETACEA 

points in common, and do not altogether come under the definition 
either of the Physeteridce or the BeljMnidce., 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 
vertebrae 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?- — 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. Maxillse 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 rudimentarj^, -srithout 
crystalline lens. External respiratory aperture longitudinal, linear. 
VertebrsB : C 7, D 10, L 9, C 26 ; total 52. A small c^cum. No 
pelvic bones. Dorsal fin represented by a low ridge. 

One species, P. gangetiai, entirely fluviatile, being extensively 
distributed throughout nearly the whole of the river systems, not 




Fig. SS. — Platanista gangeiica. (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.^ 



' Wagler, Syst. Amphib. etc., p. 35 (1830). 



- The anatomy of Platanista is fully described by J. Anderson, Zoological 
Results of Two Expeditions to IVcstcrn Yumum, 1878. 



PLATANISTIDM 259 



Inia} — Teeth variable, from 26 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. Vertebras : C 7, D 13, L 3, C 18 ; total 
41. Transverse processes of lumbar vertebrae very broad. Sternum 
short and broad, and consisting of a single segment only. Dorsal 
fin a mere ridge. The long cylindrical rostrum externally furnished 
ivith scattered, stout, and crisp hairs. One species only is known, 
I. geoffroyensis, about 7 feet in length, inhabiting the upper Amazon 
and its tributary streams. 

Pontoporia.^ — Teeth 50 to 60 on either side of each jaw, with a 
cingulum at the base of the crown. Jaws very long and slender. 
Vertebrse: C7, DIO, L5,C19; total 41. Transverse processes 
of the lumbar vertebrae extremely broad. Sternum elongated, 
composed of two segments, with four sternal ribs attached. Dorsal 
fin rather small, triangular, pointed. External respiratory aperture 




Pia. S9.— Poii«opoi-jci UainviUH. (From Burmeister.) 

transverse, crescentic. This genus connects the last two forms with 
the true JDelphinidce. The only species, P. blamvillei, 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 farms. — 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 
SchizodelpUs are generally referred to the present family. The 
former has wide transverse processes to the lumbar vertebrae, as in 
Inia, 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, Bhabdosteus, etc., are referred by Professor E. D. Cope to 

' D'Orbigny, Nouv. Ann. Mus. Paris, vol. iii. p. 31 (1834). 
2 Gray, Zoology of Erebus and Terror, p. 46 (1846). 



26o CETACEA 



this family. Agabelus, from the same deposits, is an apparently- 
allied, but toothless type. 



Family Delphinid.i. 

Teeth usually numerous in both jaws. Pterygoid bones short, 
thin, each involuted to form with a process of the palate bone the 
outer wall 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 articidation with the 
free border of the tympanic ill-defined, and situated close to one 
edge. Transverse processes of the dorsal vertebras gradually trans- 
ferred from the arches to the bodies of the vertebra without any 
sudden break, and becoming posteriorly continuous serially with the 
transverse processes of the lumbar vertebrae. Anterior ribs attached 
to the transverse process by the tubercle, and to the bodj^ 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 gToup, 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 difiiculties in grouping them into natui'al subfamilies. 
Even the formation of well-defined genera is by no means satis- 
factory in all cases. They may, however, be divided, perhaps 
artificially, into two groups. 

Gi-oup A. — Head rounded, without distinct rostrum or beak. 
Eostrum of skull about as long as cranial portion. 

Mmwdon} — 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, projectin"- 
horizontally from the head in the form of a cylindrical, or slightly 
tapering, pointed tusk, without enamel, and ■i\dth the suliace 
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. Nat. 12tli ed. vol. i. p. 105 (1766). 



DELPHINIDM 



261 



small, not meeting in the middle line, but approxi- 
mating posteriorly. Vertebrae: C 7, D 11, L 6, 
C 26 ; 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 (M. nwiwceros), in which the 
horn-like tusk of the male often grows to a 
length of 7 or 8 feet. In very young aninials 
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 vdth 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 diff'erent 
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 



■T 



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. 
Delphinaptenis} — 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 -g- 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- 
what curved downwards. Vertebrae : C 7, D 1 1, 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 Wliale (De^jhinajiterTis le-ucas). From a specimen taken in the river 
St. Lawrence, and exiiibited in London, ISTj". 

One existing species, D. 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 

1 LacepMe, Hist. Ned. des Citacis, p. xli. (1804), 




DELPHINIDM 263 

American coast as the river St. Lawrence, which it ascends for a 
considerable distance. On rare occasions it has been seen on the 
coast of Scotland. 

Eemains of a Cetacean from the Lower Pliocene of Tuscany have 
been referred by Brandt to this genus under the name D. hrocchii 

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 vertebrae are firmly united. 

Phoccena} — Teeth f f, small, occupying nearly the whole length 
of the rostrum, with compressed, spade-shaped crowns, separated 
from the root by a constricted 
neck (Fig. 92). Eostrum rather 
shorter than the cranium 
proper, broad at the base and 
tapering towards the apex. 
Premaxillse raised into tuber- 
osities in front of the nares. 
The frontal bones forming a _„„_,, ,_ _ . ^ , ■ 

° Fig. 92. — Teeth of Porpoise. Twice natural size. 

somewhat square, elevated pro- 
tuberance in the middle line of the skull behind the nares, rising 
altogether above the flattened nasals. Pterygoids very small, 
and widely separated in the middle line. Symphysis of mandible 
very short. Vertebrae : 7, D 13, L 14, C 31 ; total 65 (subject 
to slight individual variations). First to sixth cervical vertebrse, 
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 
poissoti, 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 Meerschwein, whence the usual modern 
French name of the animal, marsouin. " 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 communis, 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, Signe Animal, vol. i. p. 279 (1817). 



264 



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, ^\ inches ; length of base of dorsal fin, 
8 inches ; length of pectoral fin, ^\ inches ; breadth of pectoral fin, 
Z\ 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 (Plwcrena 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 white. 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 diff'erent 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 flank, 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 



DELPHINWyE 



265 



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 vsrest as the coasts 
of 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 vsdth 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 n«t identical species from the American 
coast of the North Pacific has been described under the name of 
Fhoccena vomerina, and another from the mouth of the Rio de la 
Plata as P. spinipennis. 

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 (ft). It is 
lined by a thick 
white epithelium, 
which ceases 
abruptly at the 
entrance into 
next cavity, 
corresponds 
the cardiac com- 
partment of the 
stomach in the 
Ungulates and 
certain Rodents ; 
but, although its 
walls do not appear to contain peptic glands, its contents undergo 
partial digestion— probably caused by the regurgitation into it 



the 
It 
to 




Fig. 94.— Diagrammatic section of the stomach of the Porpoise, 
a, (Esophagus ; b, left, or cardiac, compaitment ; c, middle compart- 
ment ; d and e, the two divisions of the right, or pyloric, compart- 
ment ; /, pylorus ; g, duodenum, dilated at its commencement ; /i, 
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 {i 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, Glohi- 
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 Belphinus plmcrenoides by Cuvier, 
B. melas by Schlegel, forms the type of Gray's genus Xeomeris?- 
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 whether they can be regarded as constituting a specific 
character. 

Cephalm-hynchus.^ — Eostrum- 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), If to f^. Vertebrse : C 7, D 13, L 1.5, C 30 ; total 65. 
Dorsal fin low, obtusely triangular or rounded. Pectoral fins rather 

1 Zoology of Erebus mid Terror, p. 30 (1846). The name is preoccupied by 
Lamarck for a genus of Polyzoa (1816), 

2 Gray, Cat. Cetacea Brit. Mas. p. 106 (1850). 



DELPHINIDyE 267 

small, narrow, and ovate. Typified by G. lieavisidei, 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. 

Orcella} — Teeth \f to lA, 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. h-evirostris, 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.^ 

Orca.^ — Teeth about if, 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. Eostrum about equal in 
length to the cranial part of the skull, broad and flattened above, 
rounded in front ; premaxillse 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 ScJmert- 
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. ilus. p. 285 (1866). 
^ Anatomical and Zoological Researches, comjirising an Account oftlic Zoological 
Results of the tivo 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 {prca 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. 

Pseiidmxa} — Teeth about \^. Cranial and dental characters 
generally like those of Orca, except that the roots of the teeth are 
cylindrical. Vertebree : C 7, D 10, L 9, C 24 ; total 50. First 
to sixth or seventh cervical vertebrae united. Bodies of the lumbar 
vertebrae 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 R. Owen 
Phoccena crassidens. Animals of apparently the same species were 
afterwards met with in small herds on the Danish coast, and fully 
described by Reinhardt. 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. 

Globicephalus.^ — Teeth ^—^, 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. 

^ Reinhardt, Overs. Dan. Sc:xk. Fork. 1862, p. 151. 
2 Lesson, N. Tab. d. Mgnc Animal — Mamm. p. 200 (1842). 



DELPHIXID^ 269 



Premaxill;-e strongly concave in front of the nares, as wide at the 
middle of the rostrum as at the base, or wider, and very nearly or 
completely concealing the maxiUse in the anterior half of this 
region. Pterygoids of normal form, meeting, or very nearly so, 
in the middle" line. Vertebra;: C 7, D 11, L 12-U, C 28-29; 
total 58 or 59. Bodies of the anterior five or six cervical vertebras 
united. Length of the bodies of the lumbar and anterior caudal 
•vertebra^ 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 thu-d shorter (\\\\k 9 phalanges), the first, 
foiu-th, 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 ti'iangidar, the length of its base considerably exceeding its 
vertical height. 

The t}-pe of this well-marked genus is G. 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 sm-face, which is lighter. These 
animals are extremely greg'arious, and, unlike the Killers, are mild 
and inoflensive in disposition, feeding principally on cephalopods. 
Their eminently sociable character constantlj- leads to their destruc- 
tion, since when attacked they instinctivel}' rush together and 
blindly foUow the leaders of the herd. When they are seen in 
the neighbourhood of land, the fishermen endeavour to get to sea- 
ward of them in their boats, and with shouting and firing of guns 
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 
weU-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 p,(, 96.— The left penotic boue 
indistinguishable, either by external or ot GioMcephaiiis unoidens ; h-om tbe 
osteological characters, from those of the ^^.^J^'^S^,:^ 

Xorth Atlantic. anterior facet for articulatiou with 

Teeth, periotic (Fig. 96) and tym- the tympamo ; the posterior tym- 

, J. i.-u O JV„n- n™ r, panic articulation being on the op- 

panic bones from the Suffolk Crag, ^^^it.^u.oftheiigme. (From the 
described as G. uncidens, indicate a form cat. foss. .v.i.nin. bi-u. mvs. pt. v.) 
apparently closely allied to the existing 

species. "The periotic is figured in order to illustrate the dis- 
tinctive characters of that bone in the BeljpMnida'. 




270 CETACEA 



Grampus.'^ — Teeth none in the upper jaw ; in the mandible few 
(3 to 7 on each side), and confined to the region of the symphysis. 
Vertebrse: 7, D12, L19, 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. 

Feresia.^ — This genus, known at present only by two skulls, 
may be provisionally placed here. These appear to indicate a form 
connecting Globicephalus, Giwiipus, and Lagenorhynchus. From the 
latter they differ chiefly in the smaller number (about |-|) and much 
larger size (6-7 mm. in diameter at base of crown) of the teeth. 

Lagenorhynchus^^ — Eostrum 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), |-f to %%. 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, axe 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. Eostrum of skull considerably longer than the 
cranial portion. Atlas and axis firmly united ; all the other cervical 
vertebrae free. 

If we add to it the above-mentioned genus, Lageiim-hyiichus, 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 Srebus and Terror, p. 30 (1846). 

'' Gray, Froc. Zool. Soc. 1870, p. 77. 
3 Gray, Zoology of Erebus and Terror, p. 35 (1846). 



DELPHI XID.E 



Ikliilniiu^} — Tooth vory numorous in both jaws, } ;| to J;;, 
oooupyinp; iioarly tho whole longth of the rostrum, small, oloso-sot, 
conical, poiiitod, slightly oiirvod. Kostriim oloii;;atO(l, usually about 
double tho lciiL!;th of the oranial portion of tho skull. Ptcrj-goids of 
normal form, mootiui;- in tho middle line throughout thoir length. 
Talate with docp lateral grooves. Vortcbra- 73 to 75. Pectoral tin 
of moderate size, narrow, jiointod, somewhat falcate, yoeoiul and 
thiril digits well ilevelopod ; tho rest rudimoutal. 

The typo of the goims is tho Common Dolphin of the !Moditer- 
ranean (/'. ilcljiltls, Fig. 117), also found in the Atlantic, and of 




Vui. '.17.— Till' Coinniou Dolrhin (Ikt ithi n u$ ihti'lii<). I'roiii Reiuhai'dt. 

which a closely allied if not identical form is met with in the 
.\ustralian soas (JK /drsliri) and in the >,'orth Pacitic {D. bainU). 
Other species arc Jh jaiiira, D. major, etc. 

Tur^iops.- — Ivostrum tapering moderately from base to apex ; 
palate not grooved; symphysis of mandible short; other cranial 
charai'tors as in Ihlphiiui^. Teeth H ] to .;?, stout (6 to 7 mm. in 
autero-posterior diameter). "\'ertelira^ : C 7, D lo, L 17, C '27 : total 
1)4. Limbs as in Ihlpliiiiii^. Kopresonted by the widely distributed 
T. tiirsid ; T. t-iildhniiii being a second form. Fossil remains of this 
genus from the Italian riiocene have been recently described. 

rivih'ljiliiiiiisS" — Kostruui somewhat variable ; mandibuhu" sym- 
physis short (less than one-fifth the length of the ramus) ; other 
cranial characters as in the preceding geinis. Teeth i;;;- to 5j;, 
small, not exceeding 3 mm. in diameter. Vertebra' 73 to 7S. 
Limbs as in 7V//»/i /»».-;. Four leading types of this genus are 
recognised (all of which have numerous synonyms) viz. 7'. nhsntrm, 
/'. (iiphiwi/iii'. I\ i/i'iis, and P. Itiiiiiiro:<tris. 

Peron's Dolphin {Di'lj>hiiiiis kiiri'iiiiniij>hiis, Peron. or Li'uco- 
rlhviiplnis prroiii, Lilljeborg) resembles some forms of Frdih'lphimi^i in 
its cranial characters ; but having no dorsal tin, it has been separated 
generically by some writers. It is not improbable that IKIjihiinis 
hoiYdli^, Peale, from the North Pacitic. in which there is likewise no 
dorsal fin, may be an allied form. 

1^7- //(>.' — Kostrum long, narrow, and compressed, very distinct 
from the cranium ; mandibular symphysis as long as. or longer than 

1 l.inn. .N>,-.'. -Vii/. I'-Hh oil. vol. i. p. lOS (KiUn. 

- Gorv.-ii.-i. Jfiit. -V.i,'. t1,s Mammirins. vol. ii. p. l!i!;i (1S."'.''\ 

■' t!orv:ii.<. (hfuhjrcpliit- des Cclocis. p. 604 (l.'^SO^ 

■* Gray. Zoohhjif of Prdiiif ttiid Ttrroi; p. 43 vl^""i<5N 



272 CETACEA 



one-fourth the length of the ramus ; other cranial characters as in 
the preceding genus. Teeth |-]- to -ff, of comparatively large size 
(5-6 mm. in diameter) ; surface of their crowns finely grooved. 
Vertebrae: 7, D 12, L 15, C 32 ; total 66. Eepresented by 
S. rostraius, from which the forms which have received other names 
are probably not specifically separable. 

Sotalia} — 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 Steno. Teeth tolerably large (4-5 mm. in diameter), f-g- to ff, 
with smooth enamelled surface. Vertebras : C 7, D 12, L 10-14, 
C22 ; total 51-55. Pectoral fin broad at base, the breadth being 
caused by the considerable development and jDosition of the two 
outer digits. Six species are provisionally recognised as distinct, 
including the Chinese White Dolphin (S. sinensis) and S. pallidns 
from the river Amazon. 

Bibliography of Cetacea. — D. F. Esoliriclit, UnLrsiichungcn iibcr die Xordischcn 
WalUhicrc, 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, OsUographic des 
Citacis, 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 
Mim. de I' Acad. Imp. de St. PMersbourg, 7'^™= ser. vol. xx. 1873 ; C. M. Scammou, 
ilarim ilammah of the N. TV. Coast of North America, 1874 ; "\V. H. Flower, 
" On the characters and Divisions of the Families of the Delphinidcc," Proc. Zool. 
Soc. 1883, p. 466, and Zist of the Spccimmis of Cetacea in the British JIha-iiiii, 
1885 ; F. W.True, " Review of the Family Delphinida;, " 5«?/. U.S. A'at. Mkscum, 
No. 36, 1889 ; P. J. Van Beneden, Sistoirc Katurellc elcs Cetacis des Mors 
d'Eitrope, 1889. 

For fossil forms, in addition to the works of Van Beneden, Gervais, and Brandt, 
already cited, the reader may refer to various memoirs published hy the former 
writer in the Bull. Ac. li. Belgique and Ann. Mus. B. Hist. Xal. Be/,j. 
See also R. Lydekker, " The Cetacea of the Suffolk Crag," Qiuirt. Journ. Gcol. 
Soc. vol. xlii. p. 7 (1887), and Catalogue of the Fossil Mammalia iu the British 
Museum, pt. v. (1887). 



^ Gray, Cat. Seals and JVhales Brit. Mus. 2d ed. p. 393 (1866). 



CHAPTEE IX 

THE OKDER 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 Bellua^, of Linnseus, the Euminantia 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 kno^vn 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- 
dactylc 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 tubcrculated or 
ridged surfaces. There are no clavicles.^ 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. 

^ Since this was in type tlie discovery of transient rudimentary clavicles in 
the embryo of the Sheep has been announced by Wiucza {Morpholog. Jalirh. xvi. 
p. 647). 

IS 



2/4 



iWGL'LATA 



The more goneraliscd of the fossil forms do not conform in all 
respects to the above-moutioiied charartors ; (.■la^•i(.■los being present 
ill Typothcrium, and perhaps in some of the Ooudylarthra, while in 
the latter group the humerus may ha-\-e an entejiieondylar foramen, 
and thus approximate to the eorresponding bone of the Carnivora. 
Wide as is the g-ap between existing Carnivores and I'ligulates, there 
are indeed more or less strongly marked evidences of affinity 
between the earlier members of the two orders, as will be aguin 
noticed under the head of the suborder Comlylarthra. A departure 
from the normal type of foot-structure is exhibited by the extinct 
j\[acrothcnum, provisionally included in the Pcrissodactyla, where 
the digits terminated in long and eur\ed claws. 

As a general rule, the cheek-teeth liaxe distinct roots, and in 
those of the existing suborders a gradual increase in the height of 
the croi'iTis of these teeth may be noticed in jiassing 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, arc termed hrachi/doiit (Fig. l'2'2) ; while those with 
higher crowns, in which the bases of the iiifoldiiigs of enamel are 
invisible from the grinding surface, are known as lii/iisudiiiit (Fig. 12.'!). 
Again, when the tubercles on the crowns of the molars are more or 

less couc-like in form the tooth 
is said to bo hiiiio(hiiit : but wlien 
they ai'e expanded in an antero- 
posterior direction and curved into 
a crescent shape the tooth is 
dcscrilied as nt'lcnodiuit. 

The whole order may be 
divided into the Ungulata ^'el■a, 
containing the suborders Perisso- 
dactyla and Artiodactyla, and a 
somewhat heterogeneous assem- 
blage of animals which may be 
called Snbungnlata or Ungulata 
Polydactyla. Cope has pointed 
out a chara,cter in the structure 
of the t-upus by which the latter 
are dill'erentiated from the former. 
Thus in all the Subuiigulata the 
bones of the proximal and distal 
row r(itain the primiti\-e or morii 
typical relation to each other (see 
Pig. !>S) ; the OS magnum of the 
second row articulating mainly 
with the lunar of the tirst, or 
with the cuneiform, but not with the scaphoid. But in the group to 




Fia. OS.— Eight fore foot of IncUnii EIu 
plmut. X |. U, ulna ; R, radius ; c, cunoi 
form; /, lunar; so, scaphoid; u, uncilVirm 
m, maguum ; td, trapezoid ; tut, tnipozium 
I to V, first to nfth 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 ivith the more specialised 
group of the Ungulata Vera, in which the Artiodactyla will be 
taken first. 

Ungulata Vkra.^ 

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 mammae 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- 
daotyles. 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 Baridce (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 

^ Also known as Diplarthra. 
^ 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 Ehinoceroses. 

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 without a milk-predecessor. 
Xasal bones not expanded posteriorly. Xo alisphenoid canal. 




...4 ^..^ 



It 



' mMk 




Fig. 99.— Bones of right fore foot of existing Artiodactyles. A, Pig (Sus scrofa), xj; B 
Red Deer (^Cervus elaphus), xy, C, Camel (Camdm bactriamis), xi- C, Ulna; E, radius; .' 
cuneiform; !, lunar; s, scaphoid ; u, unciform ; m, magnum; Ul, trapezoid; (in, 'trapezium' 
From Flower's Osteology of Mammalia. 

Dorsal and lumbar vertebrae together always nineteen, though the 
former may vary from twelve to fifteen. Femur without* thii-d 
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 
axis or median line of the whole foot is a line drawn between the 
third and fourth digits, while in the Perissodactyles it is a line 
drawn down the centre of the third dis,at. Distal articular surface 



ARTIODACTYLA 



of the astragalus divided into two nearly equal facets, one for the 
navicular and the other for the cuboid bone. The calcaneum -nith 
an articular facet for the lower end of the fibula. Stomach almost 
always more or less complex. Colon convoluted. Cfecum small, 
riaccntii diifused or cotyledonary. JMammas 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 Tertiai-y 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 eai-liest known and most generalised manifestation have 
been the following : — 

1. As regards the toeth. Assumption bj' the grinding surfaces 
of the molar teeth either of a bunodont or of a selenodont form. 
Moditication 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. Reduction of the ulna from a complete 
and distinct bone to a comparatively rudimentary state, in which it 
coalesces more or less firmlv with the radius. Seduction of the 
fibula till nothing but its lower extremity remains. Keduction 
and final loss of external pair of digits (second and fifth), with coal- 
escence of the metapodi;U bones of the two middle digits. Union 
of the navicular and cuboid, and sometimes the ectocunciform, 
bones of the tarsus. 

;>. 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. ^lodification of placenta from 
simple diftused to cotyledonary form. 

The primitixe Artiodactyles, -n-ith the typical number (4-t) of 
incisor, canine, and molar teeth, brachydont molars, conical odon- 
toid process, four distinct toes on each foot, irith metapodium and 
all curpal bones distinct, no frontal appendages, and (in all prolia- 
bility) simple stomach and diffused placenta, were sepai-ated at a 
\-ery 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 UNGULATA 



Tragulina, and Pecora — into which the existing menibers 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 frequently present. 

Eemains 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. Hippopotamidm ; II. Suidm, or true Pigs; III. 
Dicotylidm, or Peccaries. ^ 

Family Hippopotamid.s:. 

Muzzle very broad and rounded. Feet short and broad, having 
four subequal toes, with 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 laro-e 
curved, continuously growing ; those of the upper jaw direct'ed 
downwards. Stomach complex. No CEecum. 

Hippopotamus.'^ — This genus may be taken to include all the 
known members of the family ; it appears to have been always 
^ In the table on p. 89 the Peooaries are included in the Suidcc. 
^ Linn. Syst. Nat. 12th ed. vol. i. p. 101 (1766). 



/iVpPCF0r.4Mir>-£ 



:'^ 



confined :o ilie Old TTorld. The dentition may l>e expressed by the 

lonmila i ?^1;. c\. p ,. m ^. The crowns of the molars ^Fi^. 100) 

■vrhen ^Tova present trefoil-shaped iiuiaoes of dentine ; and those of 
the premolars are sharp. The 
faciid portion of the skidl is much 

elongated, the orbits are tubular 
and very piominent, and the man- 
dible has a large rounded descend- 
ing riange Ltt its anirle. The eai-s vr: 



ai-e sm.vU. the tail is short, and the \%! 

leg-s are likewise so short that the 

belly is r.dsed but a little distatioe 

above the givtir.d. The brain is 

not richly convoluted, and dirt'ers 

very oorisideiTib'.y from that oi .,,_ 

the PiiTS. approximating in some :r '..:. 

respects to that of the Camel and 

Giraffe, bat on the -svhole star.d::.:; verv 




G-;-.. line snrtace :i a wptii i:; Isr 

much bv itself. The 



stomach of the common s'oecies is of enormous dimensions, having 




Fig. i;:.— Ti; H:: 



an axial length of 11 feet, and meastnir.g upwards of lo lect along 
the greater eiuvatiu-e. Its axis is longitttdinal. the pylorus being 
situated almost in the p>eh'if. and it is di\-ided into three distinct 
comiwitments, of which the thiixi is cvlindricai. The Mver of the 



adult is of extremelv simfle i- 'vm, eloni-ated 



. and narrow 



from above downw.irds. With the exception of a few tttfts of 



28o UXGULATA 



hair on tlie 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 tivo inches in thickness, is entirely desti- 
tute of covering. 

The common Hippopotamus {R. amphihiiis), 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 Xile which Hved for nearly 
thirty years in the gijrdens of the Zoological Society of London 
measured 1 H 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 Xile, they reach cultivated ground, thej^ do immense damage 
to growing crops, destroying by their ponderous tread even more 
than they devoru-. 

A much smaller species, laiown as the Pigmy Hippopotamus 
(E. Ubei-ietisis), inhabits some of the rivers of Western Africa, and 
is characterised by having only a single pair of lower incisors, 
lilainly on this account, it has been proposed to reg-ard this species 
as representing a distinct genus, under the name of Ch(enypsis .■ but 
since it agrees so essentially in other characters ivith 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 H. aniphiMiis ,■ but this is a feature 
generally found in young indi\aduals 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 tlie genus was widely 



SUID.^ 2Si 

s]n'ead over the Old AVorld. 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 specitically 
distinguished from H. amphibius. In the Pleistocene and Pliocene of 
India there are two species having three pairs of incisors in both 
jaws. Of those H. jjahrindkns has the second pair in the lower jaw 
very minute, and e\"idently just about to disappear ; from which we 
le;u-n that it is this pair which is missing in H. amphiUus. In the 
still more sreneralised H. simlensis the three incisors in the 
lower jaw arc of equal size. Hexaprotodont species also occiu- 
in the Upper Tertiaries of Burma ajid Algeria. Small tetra- 
protodont species (H. jvniJandi and H. minutus) have left their 
remains in enormous quantities in the caves and fissiu'es of Sicily 
and :Malta.. 

Famili/ SriD.i-. 

An elong-ated mobile snout, with an expanded, truncated, nearly 
naked, flat, oval terminal surface in which the nostrils are placed. 
Feet narroAv ; 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 ^-ariable 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 
cro'ttiis of the molars do not wear into such distinct trefoils as in 
the Hippopotamus, aiid are oblong 
in shape. The last molar of both 
the upper and lower jaw (Fig. 102) 
has an additional hinder lobe or 
talon, varying in size in the dift'erent 
species. The upper premolars ai'e 
simpler than the ti-ue molars. fig. lo:.— Oimding sm-mce of a worn 

^^/..'l l^OUtition : / -5, C- l) 4 )U third right lower mol.ir of the WUd Boar 

^ , , , , TT ' • "•' ^ J- • (<;iss.To-;i). AfterOwen. 

i; ; total 44:. Upper mcisoi-s 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 firet, the third much smaller. Canines strongly 
developed and with persistent roots and partial enamel- co^ering, 
those of the upper jaw not ha\-ing the usual dofliiward direction, 

1 Liun. .<; .n'. X.'t. lith ed. vol. i. p. 102 ^ITdoV 




282 UNGULATA 



but curving strongly outwards, upwards, and finally inwards, while 
those of the lower jaw are directed upwards and outwards with 
a gentle backward curve, their hinder edges working and wearing 
against the front edges of the upper canines.^ They appear 
externally to the mouth as tusks, the form of the upper lip being 
modified to allow of then- 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 equal (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. Vertebrse : C 7, D 13-14, L 6, S 4, C 20-24. The hairy 
covering of the body varies much under difi'erent conditions of 
climate, but when best developed, as in the European Wild Boar, 
consists of long stifi^ 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 

^ If from any accidental circumstances these teetli are not constantly worn 
down by friction, tliey grow into a complete circle, the point penetrating the 
hone 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. 



SUJDJE 



283 



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. ^ 

A. — Sus proper comprises a number of animals ^ 

found in a wild state thioughout the gieatei pait 

of Europe (except -where exteimm- 

ated by human agency), the north 

of Africa, southern contniental 

Asia, and the 
great 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 SCrofa, Fig. 103.— Left lateral view of the dentition of tlie Boar {Sm scrofa), 

the Wild Boar th<^ ™ots of the teeth being exposed by removing the external lamina 
(- T7 A • of bone. 

01 Jiurope, Asia 

Minor, and North Africa, once common throughout the British 

Isles ; S. sennaarensis, North-East Africa ; S. cristahis, India ; S. 





Fig. 104.— Left lateral view of the skull of Siis longirostris. i natural size. (From Xehring.) 

vitMus, Java, Borneo, Amboyna, Batchian ; S. papwensi^ New 
Guinea; S. timorensis, Timor and Eotti; S. andamanensis, Anda- 



284 



UNGULATA 



man Islands ; .S'. faevanu.s, Formosa ; S. leucomystox, Japan ; S. 
verracu.ms, Java, Borneo, Ceram ; S. larlatm, Borneo ; S. cdebensis, 
Celebes, Philippines, and ^Moluccas ; S. longirosfris, Borneo and 
Java. The last four species form an allied group in which the 
facial portion of the skull may be greatly 
elongated ; ,S'. harbatus and <S'. celebensis 
being characterised by the small size and 
simple structure of the talon of the third 
molars. The skull of S. longirostris is 
shown in Figs. 104 and 105. The small 
S. andamamnm also has very simple third 
molars. ,S'. nttatu?, S. leucomy-itax^ S. cris- 
fahts, S. fa'evanus, 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. Xehring is inclined to 
think that the whole 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 stiQ 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 
Xew Zealand a wild or rather "feral" 
race is already established, the origin of 
which is of course quite recent, since it is 
Fig. i05.-Fiontai aspect of ^eU ascertained that no animal of the 

tbe cranium of Sus longirostris. -, ■ -, i- i "^ ".-j. i/iic 

J natniai size. (From Xehring.) '^^^ ^ver lived upon the island untU 
after its settlement by Europeans. 
"\Miether the various breeds of domestic Pigs have been derived 
from one or several soui'ces is still unknown. As in so manv 
similar cases, there is no historic evidence upon the subject, 
and the researches of natm-alists, as Xathusius, Eiitimever 
EoUeston, Xehring, and others, who have endeavoui-ed to seUle 
the question on anatomical e^adence, have not led to anv 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 




SUIDJE 



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 with 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 
Pigs which have run wild in Jamaica and the semiferal Pigs of I^ew 
Granada 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 Si^anish 




Fig. lOG. — 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 stiU 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 Forcula, but all the alleged distinctive characters 
prove on more careful investigation to have little real value. 0'\Wng 
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 



2S6 



UXGL'LATA 



specimens in the London Zoological Gardens has. however, afforded 
opportunities for careful anatomical observation.^ 

C. — Two well-marked species ot African Smne have been with 
more reason separated under the name of Potamochani<. The denti- 
tion differs from that of the true >V>. inasmuch as the anterior 
premolars have a tendency to disappear : sometimes in adult 
specimens the first upper premolar is retained, but it is usuallj 
absent, as well as the fii-st and often the second lower premolars. 
The molar teeth are alsii less complex ; the last especially having a 




107.— The Keil River-Hojj (,Mis jw/viis). From Sclater, Guide to Animals 
m Zoolc'jCeal ^ocUty's GanUnSj 1SS3, p. ISo, 

much less developed talon. There are likewise characteristic cranial 
differences. The two species are very distinct in outwai-d appearance 
and coloration. One is .S'. africanus. the South African Eiver-Hoii\ 
or Bosch-Yark, of a gxay coloiu-, and the other ^S j).>;vh~-. the West 
African Eed Eiver-Hog (Fig. 107), remarkable for its %-ivid colouring 
and long pencilled ears. It should be noted that the younii of both 
those species, as well as of the pigmy .S. salfaniiig, present the striped 
character of the true ^'«v, a strong indication of close affinities, 
whereas in all the follo^\'ing forms this is absent. 

The genus ^^(/.*, in the above extended sense, is well represented 
in the Tertiaries of the Old "World from the period of the Lower 
Pliocene upwards. Li the Pliocene and Pleistocene of Lidia 
^ Soo Gai-son, Prix: Zoo!. So.: Loin!. ISS:"., p. 413. 



;\>.;>i.;aV, >>_\ > ^jih/h'j It'll jr.- ■/whif <M liie A'^^'OTi.-.v, ^li^^^-■f■n^\ >. J&J.B 
:.:'vV sl^;', :.< . ^■.Aivw; iVJso.; '!''\ iJli'-::;" .■, v. ,"; t. .\.: .\ ; \ s:'^\\; ■^;. ■,;■,;■> ; 

3ii:i-!-i;;r,3.ni^ > _/.//',//./, ^N■,^ I'li lit'- Diiw^i- ,^.i N . . ; :, Vi ; -i:; -,r. 1:5,5:,;i 




ri.v iitv Siina rfJ*"!.; 



^»jsa> aJ'« -laV 



;.V'/.. Y/sc. ---i\r.:.;.!,.v. » «^ c-;, ;• j . w | ; i^itaI S^. Tin- :,->ta3 
;-.:.is.i; ;-.n.: j}!r 3"«'.^ s.VjJj'rjiX ^i:y-»,-.I',:-> i-tf Ivijli ;.:.M> >irwi: ■.':'^^ :.:• 

T)K" >,',>;;.;>, !^~.V><-is?jl\ :}3f ;:,,<;, «Y >■.■.,;,.]«■ jsaji^ >,,-.'-:,.iT lJl;S31 w > - 

Iti'si lJ53- iTiiis: •;.'>!\-'n~-i-:s:-:j \ i"rf !)•, i> _i^v-,,;;> is ]in- i\3:-.'i^iv,5i-.i.-..: \ i5rA o].>}> 
»li«M vM j>if .■,•..■...;:-> >->! :.hr Ifts]?!. rhi\s;; Joi-iha T',^ ,,> ;13T 

\'is;\. s.'- liiJiJ J.br) 1n->r,: ;--.n.t'-r I.hf TOrcijlJi, l~iOT ri:r.'. ,;:^ thi^ M. .. ill 
3.br •tiuV: -,\'s,'.. Vjr "huV ,> laljjesr 3Ji;531 U>rj.>,, ,■.:!.. .■,..^;- lis, kxv-;,:\'i>.. 
.5. \«--.-.v-;v:vj>,, 4«ii3 fjriillY imrti :.i-, \>-;..\> «iT.'.Vi, .■.'.-.■.■•,»; i-cr qmn-- 
IV. .. :. ., 4.h; >.kiji i-vi jiix-. JiiwJirt»ti Yraij-lirA' : C J, P iJv 1 1 tx 
> ^., . : : ■- is "h:i: tvanf >-.a;\ ;;> , ;. n2i'ir;:.\ icmiii^ cm]y » Ti<> 

^ ij^**.il, X'rr^ il. ,1'. i. Ilk.. T. .<!.<iT (-Si' >, ' ' lAi'Jr.rjjS:!. " 



UNGULATA 



entirely devoid of hair. With regard to the curiously modified 
dentition, Wallace {Malay Archipelago, vol. i. p. 435) makes the 
following 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 were 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 Eabbit 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." 

Phacochcerus} — 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 BaUrusa. 
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\, c \, ]} ^, 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 siu-face, 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 -svith pulp-cavity, dentine, 
and enamel covering, and packed together mth 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 Pio- into 
that of PhacochcErus y and, as already mentioned, some of the fossil 
Indian and African species of Sus indicate the mode in which this 
^ Cuvier, Eigne- Animal, vol. i. p. 236 (1817). . 



DICOTYLID^ 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 Warf>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 : — P. africanus, Elian's Wart-Hog, widely distributed 
over the continent ; and P. cethiopicus, Pallas's Wart-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. 

Family Dicotylid^. 

Snout as in Suidce. Dentition : i §, c -5-, ^ f, 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 csecum. 
Confined to the New World. 

Dicotyles.^ — The teeth of the Peccaries (Dicotyles) 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 foiu'th) 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: 7, D 14, L 5, S 4, 7. 
As in the Pigs, the snout is truncated, and the 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 with thick bristly 
hair, and rather behind the middle of the back is a large and 

^ Cuvier, Eigne Animal, vol. i. p. 237 (1817). 
19 



290 UNGULATA 



peculiar gland, which secretes an oleaginous substance vpith 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,^ 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 Patao-onia. 
G-enerally 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, ynXh 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. laUatus, 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 mth in large herds of 
from fifty to a hundred or more indi^-iduals, 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 lie has pro- 
posed the name D. angnlaris. 



DICOTYUD.^ 291 



iiifli'i-rjig severe •wounds "with it; shaip TTist;. A ianter frho en- 
counter; a herd oi them in a iore;i La; ofreii to climb a tree a= 
Ids only chance of safetr. Both specie; are ommTorC'ii;. h'-rj-n^- on 
roots, fallen fmits, worms, and carrion; and when theT approach 
the neiglilxiTirhood of TiEages and cultivated lands thev ofter. 
iiiiicT j.T'iaT devastation upon the crops of the inhabitants. 

EeiiiiiiijS of the rs-o esisrinj: ;pecie; 01 Peccary, a; well a; C'f one 
much larger extinct form, are found in the cavem^ieposit; of BrazQ ; 
while laPj^e Pecearie; also occur in the Plei;tocene of the United 
>^ite;. which, although ther have been lefeiTed to a distinct ^enu-. 
Platygotms, on account of their relatively smaller iiici;or; and some- 
what simpler premolars, may well be included in DkoiyUs. 

AUieA Eziind G-iTierc-. — ^In the Tertiarr deposits of both 
the Old and Xew World occur remaia; of Pig-lite animal; 
which, so ias a; we can jadge. appear to connect the Peccaries 
so closely with the true Pig; as to render the LvyAyJidA' 
really inseparable ftom the .iiiidiT:. Of the;e the Anaeri<2an 
gemi; Chaenc^us has the lower canine with a triangular cro;; 
section and received into a notch in the upper jaw, a; in the Pec- 
caries, but the fourth upper premolar is simpler than the molars, as 
in the under-mentioned genus Hyoihicrium. The typical loini; have 
only three premolar;, but in other;, which it ha; been propo;ed to 
separate generi'ially a; Boihriol/ilii. there are four of these teeth. 
Hyoihmuin, at the Pliocene 
and Z^Iiocene of the Old 
World, i; a ^enerali;ed 
form allied both to S'U and 
Jji<xdyles a; w^ell as to certain 
extinct genera. The ujjper 
molars (Fig. 110) are char- 
acterised by their ;c[uare 

crowns the la;t having no FlcllO. — Iht three 'iett.n^peimoiaTBrjtEyoaierium 

oj-nnct third lobe, and com- 
ing ioto use before the first is much worn, while the la;t premolar is 
simpler than the true molars. The canines, which have an oval ;ection 
and are scarcely larger than the inci;or;, are not received into a 
notch in the upper jaw. In the PKocene of India there occur; an 
apjiarently aUied genu; known as Hijyjxihyu.?, in which the crowii; 
of the molars are much taller, and have lateral infolding; of the 
enamel, producing; a very complex pattern on the worn ciot;ti-. 
The European Pliocene genu; Liifriodon, with the dental formula 
J .^. c \, p ^,m I, difier; from all the preceding in having the 
anterior and po;terior pairs of tubercle; of the molar; united into 
ridge; running aero;; their crowns, so that the;e teeth resemble the 
lower molar; of the Tapir. The genu; i; also found in the Lower 
PUocene 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 
groups mentioned below so closely as to show that in a strictly 
palseontological 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. 

Chmropotamidce. — 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 Anthracotheriitm ; while the premolars are not secant, and may 
be very large. The best known forms are the small Gebochmrus of 
the Phosphorites of Central France ; Chceropotamus of the Upper 
Eocene, the type species of which was of the size of a large Pig, 
with the dental formula if, c \, p ^, m f , and no distinctly 
selenodont structure in the molars ; the much larger Elotlieriwm, 
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 Teiracoiwdon 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 AcJicenodon should perhaps also be placed here. 

Anthracotheriidce. — The genera Anthracotherium and Syopotamus, 
of the upper Eocene and Miocene, 
have the typical Eutherian dental for- 
mula ; the upper molars (Pig. 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 
the columns or tubercles will be at 
once apparent, the broken antero- 
median column representing the proto- 
conule. Some of the species are of 
large size, while others are comparatively small. 




Fio. 111.— The imperfect third left 
upper molar of Hyopotamus giganteus, 
MioceDe, India. (From the Palceonto- 
logm Indica.) 



EXr/XCT FA-V/UES 



:o; 




Fio. 112.— A righr 
upper molar of ilcry- 



M^nicojtotamiis. — The genus MeniO'j\>famus oi the lo\rer Pliocene 
of India may be leganied as an Aiithi-acotheroid which has lost 
the autero-median column to the upper molars 
(FiiT. 112\ so that these teeth are consequenth- 
quadrituberculate : and may thus be regtirded as 
t\-pical examples of the bmchy-selenodont modifica- 
tion of molai- structure. 

CrUiloj'ida: — The Pliocene genus Coti/ivj>-< (Oic- 
tMlon 1) is the t_\-pe of a laige American family in 
Avhich the upper molai-s are seleuodont and usually 
have fom- cohrmns, while the lower caiune is approxi- 
mated to the incisoi-s and its form and function Pliocene, indi.^. 
assumed by the lii-st premolar. The last upper ^^X^LT'""" 
premolar is simpler than the molars. There is no 
flange to the angle of the mandible : and the feet have fom- digits. 
The affinities of this peculiar family are probably -svidely spread, 
but they may have been derived from the Anilnvcvihinidij. The 
t\-pe irenus has the full Eutherian dentition, but in some of the 
more specialised forms {Ci/clojiidiuf) the upper incisors may be 
wanting, and large \-acuities oecm- in the laehi-\-mal region. The 
genoralisod genus Fivh'nvdoii. of the Upper or Uinta Eocene, has 
five cusps on the upper molars, ai-ranged as in the Anthiv.cvthtriida: 
The pollex is retivined in the manus of the tvpe genus. 

The family may be divided into subfamilies as follows : — 

I. Upper molars A\-itli four oolumns. 

1. Orbiis open, uo lachrymal fosM, a diastema, the last upper 
pi"emolar with two outer columns, outer wall of upper 
molars concave and inclined inwards. — Aorioi-hirimr 

■2. Orbits closed, a lachrymal fosf;i, no diastema, the last upper 
premolai- with one outer column ; outer wall of upper 
molais Jlattened. — Cotiilojuna ^Cot>i'<?}'.'. E}'jyt\v-on. M-. 7- 
cocha-rvs. CyelopuUu-. etc.] 
II. Upper luolar? with five columns. — ProioriontiniT ^Pnitoreoo.oii''. 

Anojtloi/iiriida. 
— This family in- 
cluiies several 
Upper Eocene 
Eiu'opean genera. 
with selenodont 
upper molars, 
carrying five 
columns ai'ranged 
as in Aiifhma)- 
iherium. One of 




Fio. lis. — Re^Toratiou of JH0j7^*^f"n[r; o ■.fHHne 
^Upl^^ Eocene). Ciivier. 

^ This name (Leidy. 15M i> pr?oocnpied by 0. 



,Apu<?iz. IS 



294 UNGULATA 



the earliest known, Auo'plothcmm, was fully described by Cuvier 
from remains found in the Pai'is 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 Avas in many respects a much- 
specialised form, apparently not on the line of descent of any of 
the existing groups. 

Dacrythermm is an allied genus whose dentition leads on to that 
of the smaller Xiphochm. 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 pideti, of the Swiss Eocene, is a species of Dacrytheriuw . 

Gwnotheriidce. — 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 jlntlmmithciiidiv. The known 
forms are from the Upper Eocene and Lower Miocene of Europe. 
In Cmnotherium the molars are selenodont, while they are bunodont 
in Dichohunus. Homacoclun, of the Bridger Eocene of the United 
States, is closely allied to the the latter. The first lower premolai- 
of Dichohunus assumes the form and function of a canine. Spiwio- 
therium [Metriotherium) is a much larger form, in which the molars 
are not unlike those of Aiithracotherium, if the arrangement of the 
cusps were reversed; it occurs in the Eocene Phosphorites of 
France. ^ It is suggested that the TyUipuihi, may have originated 
from this group. 

Tapirulus is a small Eocene Artiodactyle with the columns of 
the vipper molars, which are somewhat like those of J/i/ojintdiinis, 
tending to form transverse ridges; its family position is uncertain.' 

DichodontidcB. — The Euroi)ean genera included in this family all 
have quadrituberoular selenodont molars, and show signs of approxi- 
mating more or less closely to existing types. JlirJniihiii, 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 l)cing 
unknown in any other Sclcnodonts. In Lojihiomrri/.r, „i the same 
beds, the somewhat higher crowns of the, molars approximate to 
those of the C/'rvidir, but the hinder lolies of the upper ones ar-e 
imperfectly developed; the genus may l)e allicul to the Tnuiullhv. 
In the small Gelocus, of the Lower Miocene, the molars are not 



CA.MEUn.K 295 

Uliliko tlioKc of Pifhiitltiii ; bill' lli« liaviculiir aiul (■iilxiid lioiics of 
(.Ii(( liu'sus \v<'i'(t fiisod t.oj;(<llu^r, luid tho nieliiljirsiils had unitud to 
loriii a " wiiiiioii-l>oiu'," all lioi|i;li llio iiK^lacai'pals still idinaiiicd 
disliiicl. It ia not improhabki lliat iijijx^' incisors wci'c. waiitinj,' ; 
and it haa luicii sujL;g('stt^d that wo liaNc in this j^orms tho ancoslral 
ty|)o of tlio Tri(i/itli(lir and Cirridtv. 



TVLOI'IUIA. 

Fiiiiiili/ ('Ai\iKi,iit.v:. 

'I'luM };ro\i|> is i'((|)rc'S('iitod at tho ])i'(ison(. day by liio two sjx'cics 
of CaiMols of tho Old World and (bo Llamas of South Anu^rioa, 
(•oll(H'livoly coiistil-uting' tho fanuly ('iiiiii'liiltf. Tho spooial cliaraoturs 
which (ho Llamas and Cainols havo in connuon, and the condona- 
tion of whicii disliM<;insiios thom from tho rest of tho Artiodac^l ylos, 
a.ro as follows. Tho |)i'oma\illio havo tho. full mnubor of incisor 
lootli in (ho yoniii; stale, and tho oiitormostr is iKn'sistont through 
lifo as an isolated laniariform tooth. Tho eaniiios a.i-o })ros(int in 
bolh jaws, and Ihoso of tho niandiblo arc. dillorontiatod from tlu< 
lonj;, |irocun>boiil, and spat idato incisors, boiiij;- snboroct and pointod. 
Tho ci'owns of tho truo molars belong to tho croscontic or scilen- 
odont type, and ni'o very hy|)sodoiit; but oni^ or more of (ho 
anterior premolars is usuall)' do(achod from the sei'ies, and is 
of simplo poinlod f(jrm. Tlu^ audi(ory bulla is tilled with cancellous 
t'issu(<. Tho hinder part- of the body is nnich contracted, and tliti 
foimu' long and vertically ])lacod, so that- tlio knotvjoint is lowoi' 
in posit.ion, and (ho (high altogodier more dotaclK^I from tho 
abdonuin (liau in nios(. ((uadrupodal mammals. Tho limbs aro 
long, but will) only (he (bird and fourth digits (hu'olopod ; no 
(races of any of (ho others being prosen(. The ti-apozoid and mag- 
in\m of tho carpns, and tlui cuboid and na\icnlar of (ho tarsns are 
dislinct. Tho (wo nu>(apodial bones of oach limb are continent for 
tho groad'c part, of their length, (hough separated lov a considerable 
(lis(jinc(i at (ho Iowim' end. Thoir dis(al articular sui'fa<'es, iris(ea,d 
of being pulley like, \vi(h deep ridges and groo\'es, as in otlu'r rocen(. 
Ar(iodac(ylos, ai'o sinipl(\ ro\uidod, and snioodi. Tho ))ri)ximal 
phalanges arc^ expanded at their distal ends, and (he wide, d(>pressiMl 
middle phalangc^s aro oniliedded in a broad cutaneous pad, forming 
tho solo of tho foot, on which tho animal res(s in w.nlking, ins(cad 
of on (ho hoofs. Tho ungual phiilangos aro Ncry small anil nodular, 
no( lla(toned lai their inner or opposed surfaces, and not c(nuple(ely 
oncasi^d in hoofs, b\it bearing nails on their upper surface onlw 
Tlu< corxical region is long and tlexnous, iind tlio \ oitobi-aMif which 
it is couiposod are reniarkablo fin' the position of the canal for 



296 UNGULATA 



the transmission of the ^'ertebral arteiy, which does not perforate 
the transverse process, but passes obliquely through the anterior 
part of the pedicle of the arch (a condition onlj' found in two other 
genera of mammals, 3lacraiichcnia and illi/riiiecojihai/a). 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 'N'illi 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 \\-alls, with muscular septa, 
and a sphincter-like arrangement of their orifices, by which thej' can 
be shut off from the rest of the cavit}-, and into which the fluid 
portion only of the contents of the stomach is allowed to enter. '^ 
The placenta is diffuse, as in the Suina and Tiagulina, not coty- 
ledonary, as in the Pecora. Finally, the Caiiididoi 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. 

Gamdns} — Dentition of adult : i ^, (• \, p #, m f ; 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 premaxillse not articulating 
with the arched and somewhat elongated nasals. "N^ertebra^ : C 7, 
D 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 de^'eloped, 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 {Camclus dnmcdarnix), and the double- 
humped Bactrian Camel (C. hiuinumis, Fig. 114).^ The former 

^ The stomach of tlie 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 adapti\-e 
modifications. 

^ Linn. iSyst. Nat. 12th ed. vol. i. p. 90 (1766). 

3 There i,s 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 



CAMELIDJE 297 

is quite unknown in a wild state, but it is reported that wild 
Bactrian Camels occvu- 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 (Camelus bactriamis). 

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, well 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 mth 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 vertebrae 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 : i J, c y, ^ #, m f ; 
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 o-enerally 
resembles that of Camelus, the relatively larger brain-cavity and 
1 lUiger, Prodromus Syst. Mmnm. p. 103 (1811). 



CAMELIDyE 



299 



orbits and less developed cranial ridges being due to its smaller 
size. The nasal bones are shorter and broader, and are joined 
by the premaxillse. Vertebrae: C 7, D 12, L 7, S 4, C 15-20. 
Ears rather long and pointed. No dorsal hump. Feet narrow, 
the toes being more 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 




Fig. 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, 
glides, 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 



30O 



UNGULATA 



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 Gamdus in the Systema Natures of Linnseus. They were, 
however, separated by Cuvier in 1800 under the name of Lama, 
changed by lUiger in 1811 io Auchenia (in allusion to the great 
length of neck, oii-xfiv), 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- 
nised by some naturalists 
as distinct species, and have 
had specific designations 
attached to them, thouo;h 
usually with expressions of 
doubt, and vdth. 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. liiutnaciis (Mo- 
lina) ; and (4) the Vicugna, 
A. vicugna (Molina), or A. 
ricunna, (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 diff'er from each other' 




Fig. 116. — Head of Vicugna, from an animal livluo- 
in the Gardens of the Zoological Society of London. 



CAM ELI D^ 



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, 
be 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, but 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,^ 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 Bistory of the Strait of 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 G-uanaco 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, 
IDarticularly that of the species called Pacas, which have very lont^ 
fleeces ; and the expense of their food is trifling, as a handful of 
maize sufiices 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 



CAMELIDjE 303 

when one Indian had killed a sheep his neighbours came and took 
what 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. Eemains apparently referable to the existing 
species occur in the cavern-deposits of BrazdI. In the Pleistocene 
of Mexico we meet with A. (Palauchenia) 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) 
hesterna, 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) mtakeriana, 
where, however, the upper one is of simpler structure. 

Extinct Cameloids. — 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 



304 UNGULA TA 



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 -Kke 
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, we 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 I, c i, ^ A TO f ; and from this type a transition may be 
traced to Poebrotherium, 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 Leptotragidus of 
the Uinta Eocene, which appears to have been closely allied' to 
Poebrotherium. 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 mth the magnum. It is 
suggested that Leptotragulus may have been derived from the 



TRAGULID^ 305 



Bunodont genus Homacodon of the Bridger Eocene, mentioned 
among the Ccenotheriid(e. 

Tragulixa. 
Family Teagulid^. 

Xo teeth in premaxillae. Upper canines well developed, especi- 
ally in the males ; narrow and pointed. Lower canines incisiform. 
Xo caninifoma 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 -f. 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. Xavicular, cuboid, and ectocunei- 
form bones of tarsus united. Tympanic bullas of skull fiUed with 
canceUar tissue. Xo frontal appendages. Euminating, but the 
stomach with only three distinct compartments, the manipHes or 
third cavity of the stomach of the Pecora being rudimentary. 
Placenta diffused. 

This section is represented only by the single family TraguUdce-, 
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 
Jfoschus, 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 palaeonto- 
logical researches among allied forms ; and most obdurate, inasmuch 
Hs aU 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. 

Tragulus,^ containing the smallest of the existing Ungulates, 
animals having more of the general aspects and habits of some 
Rodents, as the Agoutis, than of the rest of their own order. The 
best -known species are T. javanicus, T. napu, T. stanleyanus, and 

^ Pallas, Spicilegia Zoologica, vol. xiii. p. 27 (1779). 
20 



3o6 



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. 
Dorcatherium ^ 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 Tragulus) is usually i ■§•, c \, p |, m |- =34. Vertebrae : C 7, 
D 13, L 6, S 5, C 12-13. The only existing species, D. aquaticuin 
(Fig. 118), from the west coast of Africa, is rather larger than any 








'^''^tkt^ //* 






Fig. lis.— The African Water-Chevrotain (Dorcatherium aquatimm). 

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 (B. 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 

^ Kaup, Ossemens Fossiks de Darmstadt, pt. 5, p. 92 (1836). This name 
which was proposed for a fossil species, antedates Myomoschus, Graj', applied to 
the living form. 



PECORA 307 

from various Miocene and Pliocene deposits appear to connect the 
modern Tragulina so closely with Gelocus (p. 294), and thus Avith 
the ancestral Cervidce, 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. Prodremotherium, 
of the Upper Eocene Phosphorites of France, differs in that the 
metacarpals also form a cannon-bone ; while in the American 
Hypertragulus, both metacarpals and metatarsals remain separate. 
Bachitherium, of the French Phosphorites, apparently presents 
afiinity with Gelocus, 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. 



Pbcora, or Cotylophora. 

No premaxillary teeth or caniniform premolars. Upper canines 
generally absent, though sometimes largely developed. Inferior 
incisors, three on each side with an incisiform canine in contact 
with them. Molariform teeth consisting of p f, m f, in con- 
tinuous series. Auditory bullse 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.-*^ 

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 diSerent organs (feet, skull, frontal appendages, 
teeth, cutaneous glands, etc.) have proceeded with such apparent 
irregularity and absence of correlation that the different modifica- 

^ For tlie anatomy of this group see A. H. Garrod, Proc. Zool. ,Soc. 1577, 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 Gervidce and the Bovidm, — otherwise the 
antlered and horned Euminants. Intermediate smaller branches 
produced the existing Musk-Deer and Giraffe, as well as the extinct 
HeUadotlierium inclining to the first^named group, and the extinct 
SivatJieriwn, Brahnatherium, 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 (Tekaceros 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. " Antlers " ai-e outgrowths 
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 

Fro. 119.— A shed right antler of the Red Deer a^nd is " shed " (Fig. 119). A 
<Ce™is eiapTms), found in an Irish lake, a, Brow rtlOre Or leSS elonsated portion 
tine; &, beztine; c, trestine; (^, crown or royal ^ ic j* i jj i ■ 

tine. (After Owen.) '^^ pedicle always remains on 

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 gi-adually tapering. 
Sometimes they are more or less expanded and flattened the 




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 
they 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 
existing Deer of 
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 Eeindeer), 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 hez tine, and the third one the tres tine ; the mass of 
points at the summit of the antler being termed either the royal 
and smroyal 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 hm: 




Fig. 120.- 



irai 



'^m 



-Head of Deer {Cervus schomburgki), showing antlers 
From Sclater, Proc. Zool. Soc. 1877, p. 682. 



3IO 



UNGULATA 



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 
CO ntinuously, 
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 
{Antiloaipra), 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 

-Head of Antelope (ffazeZiffi/ranM), showing horns. From malo= r.f oil o^Jc*. 
Sir V. Broolte, Proo. Zoo!. Soc. 1878, p. 724. males Ot all exist- 




FlG. 121.. 



ing .Boj'if^fE possess 
them, and they are also present (though usually not so fully 
developed) in the females of all except the genera Bosdaphus, 
Strepsiceros, Tragelaphus, Antilope, Mpyc&ros, Saiga, Cohiis, Cenicapra 
Felea, Mnoira.gus, Neoiragus, Cephalophus, and Tetraceros; as well as 
in some species of Gazella, such as G. pidicaudata and G. walleri 

Another character by which different members of the Pecora can be 
distinguished among themselves is derivedfrom the nature of themolar 
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 



PECORA 



i:;(.Mierally be distinguished, inasmuch as the true molars of the Vervuhv 

ai'c more or less brachydont, and those of the BofiiJw generally 

hypsodont, i.e. the teeth of the former ha^'o 

comparatively short crowns (Fig. l'2'2), which, 

as in most mammals, take their place at once 

with the nock (or point ^vhore the crown and 

root join) on a level with or a little above the 

alveolar border, and remain in this position 

throughout the animal's life ; whereas in the 

other forms(Fig. 1 :23),the crown being lengthened 

and the root small, the nock does not come up 

to tiio alveolar level until a considerable part 

of the surface has worn away, and the crown of 

tlie tooth thus apjicars for the greater part of 

the animal's life partially buried in the socket. 

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 




Fig. I'J^. — Crown sur- 
face of n -woni left upper 
molar of r(ihvomff!i.v siva- 
It'iisi.^, to show bracliydout 
typo. (From the Pala-onlo- 
logia ])uUca.) 





Flo. 1-J;i.— Iimoi- tmi outer aspects of an .almost nnwoni left upper molar of the Nilghai 
(/iisc/njJiiis Iriuixamdiis), to show hypsodont f)po. (From the I'tilaoiilologla Imlica.) 



in the first-described they diA'crge 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, aiul is entirely or nearly wanting in the short- 
crowned teeth. The same modification from low to high crowns 
>vithout essential alteration of pattern is seen in an e^■en still 
more marked manner in some of the Perissodactyle Ungulates, 
the tooth of the Horse bearing to that of Jnchithciium the same 
relation as that of an Ox does to the earlv selenodont Artiodactyles. 



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 ivith. Even among 
the Deer themselves, as pointed out by Lartet, the most ancient 
have very short molars, and the depressions on the grinding sm-face 
are so shallow that the bottom is always visible ; while in the Ccriidw 
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 Antekpes (as 
Tragelaplms) retain much of the brachydont character, which is, 
however, completely lost in the more modern and highly specialised 
Sheep and Oxen. 



"\ii 




Fig. 124.— Stomach of Euminaut opened to show internal structure, a, CEsophagus ; h, 
rumen or paunch ; c, reticulum or honey-comb bag ; d, psalterium or mauyplies ; c, ahomas'um 
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 Eeticulum 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 wide 
orifice of communication with the second stomach or honev- 
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 manyplies is globular in form, and its lining membrane 
is raised into longitudinal folds or laminse 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, ajid undergoes a further trituration by the molai- 
teeth and mixture with the secretion of the salivary and buccal 
glands. It is then swallowed again, but now passes directly through 
the before-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 festal 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 
Moschus). This family contains numerous species, having a wide 
geographical distribution, ranging in the New World from the Arctic 



314 



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} — The Musk-Deer (Fig. 125) in many respects stands by 




Fig. 125.— Tlie Musk-Deer (Jdosoh-us moscTiiJerus). 

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 (Eydivpotes) • 
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. Vertebrae : C7, Dl4 L5 S5 C6 
Among the anatomical peculiarities in which it differs from all 
true Deer and agrees ivith the Bovidce is the presence of a gall- 
^ Linn. Syst. Nat. 12th ed. vol. i. p. 91 (1766). 



CERVID.-E 315 



bladtlt'i-. The hemispheres of the brain are but sHghtly con^-oluted, 
and the cotyledons of the placenta are arranged in a peculiar linear 
manner. 1 

Although, owing to variations of colour presented liy different 
individuals in different localities and seasons, several nominal species 
have been described, zoologists are now generally agreed that there 
is but one, the Moschun moschifenis of LinuiBus. In size it is rather 
less than the European Roe 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 groat 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 pecu.liarly brittle and pith-like character, 
breaking with the application of an extremely slight force ; it is 
generally of a grayish-bro^vn colour, sometimes inclined to yellowish- 
red, and often variegated Avith 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-Avest and Cochin-China on the south-east, 
always, however, at considerable elevations, — being rarely found in 
summer below 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 tlay-time. It is a hardy, solitary, and retiring 
animal, chiefly nocturnal in its habits, and almost always found 
alone, rarely in pairs, and ne-ver 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. 

]\Iost of the animals of the group to which the Musk-Deer 
belongs, in fact the large majority of mammals, have some portion 
of the ctitaneous siu'face peculiarly modified and provided with 
glands secreting some odorous and oleaginous substance specially 
characteristic of the species. This, correlated ^viih 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 jiroseuce 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, 
,is in Sheep, sometimes on the face in front of the eyes, as in many 

' Far the anatomy o{ Afoschios see Flower, Proc. Zool. Soc. lS7o. p. 159; 
and Garrod, ibid. 1S7", p. iS". 



3i6 UNGULATA 



Deer and Antelopes. Sometimes it is in tlie 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 nan-ow 
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 ^ the - 
existing Gervince 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 premaxillse nearly always articulate -with the nasals. 

Cervulus.^ — 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- 
maxilla3 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 

' Proc. Zool. Soc. 1878, p. 889. 
- Be Blaiiiville, BiiU. Soc. Philom. 1816, p. 74. 



CERVID.£ 317 



Cemihis of BlainviUe and most zoologists : — Sti/Iocerug of Hamilton- 
Smith, and Prox of Ogilby. They are all of small size compared 
■nith the majoriiy of Deer, 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 gixing off a very short broTV tine, inclines backwards and up- 
wards, is unbranched and pointed, and when fully developed ciu'ves 
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 ser^-ing 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 sti-ongly developed and sharp, ctuTing 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 
foimd 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 Mtintjacs are sohtary 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 
eomini; to the skirts of the woods at morning and evenina; to 
graze. They carry the head and neck low 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 throtigh tangled 
tuiderwood. They are often called by Indian sportsmen "Barking 
Deer," a name given on account of ■their alarm cry, a kind of 
short shrill bark, Hke that of a fox but louder, which may often 
be heard in the jiuigles they frequent both by day and by night. 
WTien attacked liv dogs the males use their sharp canine teeth 
with great ^^gour, inflicting upon their opponents deep and even 
dangerous wovmds. 

There is some difference of opinion among zoologists as to the 
number of species of the genus Cernihi.?. Sir Victor Brooke, who 
investigated this question in 1S78 (iee Prociedings of fhf Zoological 
Sjckti/ (f London for that year, p. S9S). came to the conclusion that 
there are certainly three which are quite well marked, ■viz. — 

C. muntja: (Fig. 126), foimd in British India, Bm-ma, the Malay 
Peninsula. Sumatra. Java, Hainan, Banca, and Borneo. The general 



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 sj)ecimens from Java, Sumatra, and Borneo are 




Fig. 126.— The Mmitjac (Cermilus 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 S^vin- 
hoe, from Moupin, and near Hangchow, China. 

C. 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. fees. 

Small Deer from the European Pliocene have been provisionally 
referred to Cervulus, but the so-called Frox furcatus, of the Miocene, 
is now included in Falceomerijx. 

FHaphodus.^— Antlers very small, unbranched, supported on long, 

^ Milne-Edwards, Kcntv. Arch, du Musimn, vol. vii. Bull. p. 93 (1873). 



CERVIDAS 



319 



slender, converging pedicles. Ascending rami of premaxillse shorter 
than nasals. No supraorbital ridges or frontal glands. Ui^per 
canines of male long, but not everted. A distinct frontal tuft 
of hair. Other characters as in Cervulus. 

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 



'A_^ 




4 -xix 



Fig. 1'27. — Male of Elaphodus inichianus. From Selater 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 mesoouneiform 
may also ankylose with the ectocuneiform, and traces of the meta- 
carpals may remain. The hair is coarse and somewhat quill-like. 

Cervus} — The great majority of the Deer of the Old World may 
be included in this large genus, which is one not easy 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. Vertebrae : 7, D 13, L 6, S 4, 11-14. The size of the 

1 Linn. Syst. Kat. 12th ed. vol. i. p. 92 (1766). 



320 UNGULATA 



lachrymal fossa and vacuity, and the degree of inflation of the audi- 
tory bulla, are subject to variation in the difi"erent groups into 
which the genus may be divided. 

The Eusine group is characteristic of the Oriental region, where 
it is typically represented by the Sambur (C. aristotelis) of India, 
Biurma, and China. The antlers are rounded, and often strongly 
grooved, without a bez tine, and -ivith 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. 0. equinus, of Borneo, Sumatra, and 
Singapore, C. swinhoei, of Formosa, C. philippimis, 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 Roe. C. hippelaphus of Java, 
C. timoriensis, and C. moluccensis are distinguished by the posterior 
branch of the beam of the antler being considerably larger than the 
anterior. 

The Bucervine 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 Eusine 
group ; the large brow tine is given ofi' from the beam at an obtuse 
angle and curves upwards ; the beam bifurcates into two branches, 
which again divide. Skull as in the Eusine 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 Elaphurine group is represented only by the very aberrant 
C. davidianus 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 ofi' a long and 
straight back tine (correlated by Sir V. Brooke with the posterior 
branch of the Eusine antler) ; the summit of the beam is forked 
and in old individuals the two tines of the fork may again branch. 
JS'asals 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 Axinc group includes only the well-known Axis of India, 
readily distinguished by the white spots with which the body is 



CERVID^ 



321 



marked. , Antlers of a . Eusine 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 Palaearctic region, frequently known as the Pseudaxin& 
group, which appears to connect the Axine with the Elaphine 
type. Well-known representatives of this group are G. sika (Fig. 
128) of Japan, 0. mantchuricus of China, and C. taevanus of Formosa. 




FiQ. 128. — The Japanese Deer ^Ceruus sika). From Lord Powerscourt, Proc. Zool. Soc. 
1SS4, p. 20E1. 



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 
moderately 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 PHocene of Europe, such as C perrieri 
and C. etueriarmn, appear to be allied both to the Pseudaxine and 
Axine groups. 

The Maphine 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 



322 



UNGULATA 



number of snags, often arranged in a cuiD-like manner. Skull as 
in the preceding group. All the species large. The Eed 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 Eusiiie 
species) are spotted, are born at the end of May or the beginning 




Pig. 129.— Head of the Wapiti (Cervus caimdetisis). 

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 
m the cave-deposits of England and the Continent antlers are met 
with rivalling those of the Wapiti in size ; these large fossil antlers 



CERVIDM 323 



probably indicating tbe ancestral form from which, the Eed Deer 
and several of the allied species are descended. 

The North American Wapiti (Cervus canadensis, Fig. 129), the 
Persian Maral (C. niaral), the Kashmir Stag {G. cashmeerianus), as 
well as 0. affinis of Tibet, are all closely allied to the Eed Deer, but 
are of larger size, this being especially the case with the first two. 
A fine 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 Eed 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. 
mesopotamicus) 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. hrowni and C. falconeri appear to have been closely allied to the 
existing species. The remarkable 0. verticwnis, 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 brow 
tine, a small bez tine, and a third posterior tine. The skeleton 
measures upwards of 6 feet at the withers. Eemains 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 



UNGULA TA 



terised by retaining the distal extremities of the lateral (second 
and fifth) metacarpals. With the exception of Alces, Capreolus, 
and Hydropotes (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). 




Fia. 130.— Skeleton of the Gigantic Irish Deer (flervus gigantms). After Owen. 



Bangifer.^— The Eeindeer, or Caribou as it is termed in North 
America, is the sole representative of the genus Bangifer, 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 Eeindeer is a heavily built animal, with short limbs, in which 

1 Hamilton-Smith, in Griffith's Animal Kingdom, vol. v. p. 304 (1827). 



CERVIDyE 



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 
(Fig. 131) are 
of very large 
relative size. 
There is a bez 
as well as a 
brow tine, which 
are peculiar in 
being either 
branched or 
palmated. In 
the American 
race (Caribou), 
as well as 
in some of 
the specimens 
found fossil in 
the English 
Pleistocene 
(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. Vertebree : 
7, DU, 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 
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 




Fia. 131. — Skull and antlers of tlie Reindeer (Rangifer tarandus), 
from an English Pleistocene deposit. 6r, Brow tine ; ie, bez tine. 
(After Owen.) 



326 



UNGULATA 



for beneath the snow. The wild Eeindeer 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. 
Eemains referable to 
the existing species are 
found in the cavern 
and other Pleistocene 
deposits of Europe. 

^/tr5.i— The Elk or 
Moose {Alces marliJis) 
has the same general 
distribution as the 
Eeindeer, and is like- 




FiG. 132.— Hinder part of the base of the cranium of the 
Virginian Deer (Cariacus virginianus). From Garrod, Proc. 

zooi. soc. isrr, p. 13. 



IS 

wise the single existing 
representative of its 
genus. It is the largest 
existing member of the 
family, attaining some- 
times a height of S feet 



at the withers. 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 suflPer much inconvenience from the great 
expanse of their antlers, as in making their way amono- "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 
1 Hamilton-Smith, in Griffith's Avimnl Kiniidom, vol. v. p. 303 (1827). 



CERVID^ 327 



principal weapons, and with a single blow from the latter 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} — A remarkable extinct Deer from the Pleistocene of 
North America, described as Cervalces, appears in some respects 




*' ^ 



Fig. 133.— Head of Elk (^AUesmacklis). 

(although a true Telemetacarpalian) to connect Alces with C'erms. 
Thus the palmated antlers are divided into anterior and posterior 
branches, but below this division there are two tines apparently 
corresponding to the bez and posterior tines of Oervus giganteus 
(Fig. 130). 

Owpreolus.^ — 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. Premaxillse not 
always articulating with nasals. Auditory bullae slightly inflated, 
rugose externally. Vertebrae : C 7, D 1 3, L 6, S 6, C 8. Tail very 
short. G-lands in fore feet rudimentary ; large in hind feet. 

The Eoe, or Eoe Deer (Cap-eolus caprea), is a small form dis- 

^ Scott, Proc. Ac. Nat. Sci. Philad. 1885, p. 181. 
2 Hamilton-Smith, in Cfriffith's Animal Kingdom, 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 Capredus. 

Hydropotes} — No antlers in either sex. Lachrymal fossa deep 
and short (Fig. 134) ; lachrymal vacuity of moderate size. Orbits 




Fio. 134.-The left lateral view of the skull of a male CMnese Water Deer (Evdrovotes 
tmrmls), 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. Vertebrae: 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 (ff. inermis) is the 
sole representative of this 
genus. In the absence of 
antlers and the large can- 
ines of the male it resem- 
bles MoscJms, although very 
diff'erent in other respects. 
Thus the brain (Fig. 135) 

convoluted, as in other Cervince, and approxlLltL toThat^of pX^- 
^ Swinhoe, Proc. Zool. Soc. 1870, p. 90. 




Fig. 136.— Upper surface of the brain of Hydropotes 
inermis. (From Garrod, Proo. Zool. Soc. 1877, p. 792.) 



CERVIDjE 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 Eydropotes 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 Flatyprosopus, presents such 
a marked remblance to Hydropotes in the form of the angle as to 
suggest a more or less intimate affinity. 

Cariams} — Skull (Fig. 132) with the vomer dividing the 
posterior nares into two distinct chambers ; premaxillse not reach- 
ing nasals. Antlers never greatly exceeding the length of the head. 
Lachrymal vacuity very large, and lachrymal fossa small. Auditory 
bullae slightly inflated. Vertebra: C 7, D 13, L 6, S 4, C13. 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 Gervus. 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 0. mezicanus and other forms, the antlers do not divide 
dichotomously, and the lachrymal fossa is of moderate depth. The 
Mule Deer (0. inacrotis) 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. 
jpaludosus 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. cMlensis and 
C 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 bullae slightly 
inflated, and rugose. Upper canines may be present. The species 
are of medium size. 0. 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. 



UXGULATA 



of the hair on the face, agrees yrixh the next one in having simple 
spike-like antlers. 

The South American Coamnc group comprises the small forms 
known as Brockets, in which the antlers form simple spikes not 
exceeding haK the length of the head. Some six species are known. 

Eemains of Cariacus, mostly or entirely refei^able to existing 
species, are of common occurrence in the Brazilian care-deposits. 
BJaitomeryx, of the Pliocene of Xorth America, is believed to be an 
allied type. 

Pudua.^ — Antlers in the form of minute simple spikes. 
Distinguished from the Coassine group of Cariacus by the articulation 
of the premaxillie with the nasals (as in the Furdjerine group), 
and the coalescence of the ectocuneiform with the nayiculo-cuboid. 
as well as by various external characrers. Xo upper canines. Re- 
presented only by the very sm^ P. humiUs of the Chilian Andes. 

E.rtind Genera. — ^In the European and other Tertiary deposits 
several genera of extinct Cercida occur, of which the more important 
may be briefly mentioned. Amphitragulus, of the Lower Jkliocene 
of the Continent, has foiu: lower premolars, brachydont molars, and 
no antlers ; the largest species being somewhat bigger than the 
Miisk-Deer. The closely allied Palaomeryx {Dremotkirium or Micro- 
meryx) generally has but three lower premolars, and the brachydont 
upper molars (Fig. 122), Kke those of Amphitragvlus, want the small 
accessory inner column- found in modern Deer. In P. fdgnou.xi, of 
the Lower ^Miocene, the lateral metacarpals, although slender, were 
complete, and the males had large canines, but no antlers. 
P.furcatus, of the ^liddle ^Miocene, had small antlers, and the canines 
appear to have been reduced in size. This genus, besides being repre- 
sented in the Eirropean Miocene, also occui-s in the Pliocene of Lidia 
and China : some of the species being as large as the Eed Deer. 



Family Giraffidj:. 

In the existing genus the frontal appendages consist of a paii- 
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 skuU, covered externallv 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 with age. and 
is sometimes spoken of as a thiid horn. SkuU with a lachn-mal 
vacuity. Xo upper canines. :Molai-s brachydont, with niirose 

^ Gray, Pnv. Zool. Slv. ISoO, p. 242. 

= This accessorj- column is sliown in the figure of the molar of £o^-Inr,htts on 
p. 311. 



GIRAFFIDyE 



331 



enamel ; tlie upper ones having no inner accessory column. Lateral 
digits entirely absent on both fore and hind feet, even the hoofs 
not developed. Humerus -with double bicipital groove. Vertebrae : 









FiG. 136. — The Giraffe {Giraffa camelopardalts). 

C 7, D 14, L 5, S 3, C 20. Gall-bladder generally absent. Male 
reproductive organs and placenta of a Bovine type. Dentition : 

« 4 c ■?. P I. ''« I- 

Giraffa.^ — The Giraffe (G. camelopardalis) is the sole existing 
representative of the genus, now confined to the Ethiopian region. 

^ Zimmermann, Geograph. Gcschichte, vol. ii. p. 125 (1780). 



332 UNGULATA 



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 1 6 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 G-iraffe 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 species 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 Bovidce, 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, irith 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 Giraffidce 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 Fishnutherium, of the Pliocene of India 
and Burma, seems to make the nearest approach to the Giraffe, but 



ANTILOCAPRIDM 333 

the limbs and cervical vertebrae were decidedly shorter, although of 
a similar slender type. Eelladotherium, 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 vpith 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 Sivatherium 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 vnth. 
the Antelopes. The skxill 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 t}iQBovidce, but the horns deciduous and branched. 

Antilocapra} — 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. 
When the horn is about to be cast ofi" 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. Jmim. de Physique, vol. Ixxxvii. p. 149 (1818). 



334 UNGULATA 



Family BoviD^. 

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 Gervidm 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 mth 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 characterised by their 
great height at the withers as compared with the rump. SkuU 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. 

Alcelaplius.'^ — If Damalis 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 mammte. 
^ Blainville, Bull. Soc. Philom. 1816, p. 75. 



BOVID.E 



335 



In the typiccal forms, such as the Buhaline Antelope {A. buba- 
liiiiis), the Harte-beest (J. caaimi, Fig. 137), ;ind the Tora Antelope 
{A. turn, 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- 
beost, which is found throughout Central and Southern Africa, 
stands nearly 5 feet high at the ^^'ithers, 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 Alcehvphus {A. pahvimlkus) 




Fm. 137. —The Hnrte-lu'ost {Alcdnphns caama). 

in which the skull had the long facial portion characteristic of the 
typical group, while the horns approximate to those of the 
Ixnitebok. The Blessbok (A. albifrons) and Bontebok {A. 2'i/iWJ"'^)> 
belonging to the genus Ihmalis 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. 0. J. Anderson observes that " it is of a beautiful 
violet colour, and is found in company with black AMldoboests 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 jiastiu'e on the grassy products of these plains, 
which ailbrd 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 Tvas written these Antelopes 
have been greatly reduced in number. A. {Damalis) hunteri, from 
East Africa, appears to be aUied to A. senegalensis, but in the more 
elongated facial portion of the skull approximates to the Harte-beest, 
and thus confirms the -nevr that Damalis should not form a distinct 
genus. 




Fig. 138.— Head of Alcelaphus tora. From Sclater, Proc. Zool. Soc. 1S7S, p. 702. 

Conmcketes} — Head short and massive, with the muflaie very 
broad and bristly. Nostrils widely separated, hairy within. Horns 
on the vertex of the skuU, 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. TaU very long, covered throughout with long 
hairs. Four mammee. Two species, C. taurina and C. gnu (Fig. 139), 

' lAQ]iteustem, Berlin Ges. Katuforsch. Frewnde Maga-in vol vi pp 152 165 
(1814). 



BOVIDM 



337 



both from South Africa. The former, or Brindled G-nu, 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 Eiver. 

The AVhite -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 




"""""" /,f 



Fia. 139. — The White-tailed Gnu (Connochcetes gnu). 

development of the horns of the Gnu,^ 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 
being 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. 

Ce.plialuphine Section. — Small or medium-sized African and 
Indian Antelopes, with simple horn.s 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. 1889, p. 2. 
22 



338 



UNGULATA 



Cephalophus} — 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. 
sylvicultm- and C. longiceps are the largest species. 

Tetraceros.'^ — 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. qmidricornis). 

The Four-horned Antelope is found 
throughout the peninsula of India in 
jungle. The general colour is broivn, 
lighter beneath and on the inside of 
the limbs. Remains of this species 
are found fossil in the cave-dejDosits 
of Madras, and a small Euminant from 
the Pliocene of the Siwalik HiUs has 
Fig. i40.-Paiataiand outer aspects of ^^^en provisionally referred to this 




the three right upper premolars and first genUS. 
molar of the Four -horned Antelope {Tetra- 
euros qiiadricornis). From the PalcEon- 
tologia Indica. 



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, premaxillte 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. saltiamis), from Abyssinia, 
and also N. IdrU and N. damarensis ; the two latter having a small 
third lobe to the last molar. Writing of the first-named species, 

^ Hamilton-Smitli, in Griffith's Animal Kingdom, vol. iv. p. 258 (1827). 
Taken to include Grimmia, Terplione, etc. , of Gray. 
- Leach, Trans. Linn. Soc. vol. xiv. p. 624 (1823). 
^ Hamilton-Smith, in Griffith's Animal Kingdom, vol. iv. p. 269 (1827). 



BO VIDyE 339 



Mr. W. T. Blanford ^ observes that " the Beni-IsraeJ, or Om-dig-dig, 
one of the smallest Antelopes known, abounds on the shores of 
the Eed Sea and throughout the tropical and subtropical regions of 
Abyssinia. 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." 

ISfanotragus.^ — Horns small, parallel with frontals, and rising 
immediately above postorbital process of frontals, in front of the 
fronto- parietal suture. Lachrymal fossa very large, suddenly 
descending in front of the orbit, and extending on to the 
maxUla ; 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.^ 

The typical species is the Eoyal Antelope (jV. pygmmus) of 
Guinea, the smallest existing representative of the Pecora. This 
species, together with N. moschatus and N. traguhts have no lateral 
hoofs, or tufts on the knees. In the Scopophorine group, comprising 
N. scoparia, iV". montanus, and N. hastatus, both these appendages 
are present ; while in the Oreotragine group (iV. melanotis and 
N. oreotragus) the former are present and the latter absent. 

Pelea.^ — Horns rather small, compressed, upright, scarcely 
diverging, and placed immediately over the orbits. No suborbital 
gland, nor lachrymal fossa ; premaxillae not reaching nasals. Tail 
short and bushy. Colour uniform. One species — the Eehbok 
{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 dilfers widely from the Water-buck and 
its allies. 

Cobus.^ — Large Antelopes, with the horns large, elongate, sub- 
lyrate, and ringed at the base, and with rudimentary suborbital 
glands. Skull -svith a deep frontal hollow, no lachrymal depression, 

' Geology and Zoology of Abyssinia, p. 268. 

2 Sundevall, Kongl. Vetensk. Akad. Sandl. for 1844, p. 191. Taken to 
iuclude Galotragiis, Scopophorus, Nesotragus, Pediotragus, and Oreotragus of Gray. 

= See V. Brooke, Proc. Zool. Soc. 1872, pp. 642 and 875. 

* Gray, Cat. Ungulate Mamm. Brit. Mus. p. 90 (1852). 

^ Andrew Smith, Illustrations of Zoology of South Africa, Xo. 12 (1840), 
" Kobus." Is taken to include Adenota and Onotragus of Gray. 



340 UNGULATA 



large lachrymal vacuity, and the premaxillfe 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 Cohus, but it has 
no distinct supraorbital pits. 

Cervicapra} — 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 {G. arundineum) is of a grizzly ochre colour ; it 
stands nearly 3 feet in height, and has horns about 1 foot in 
length. The Nagor (0. redunca) is about 6 inches shorter, with 
horns of half the length, and fulvous brown above and white 
below ; the West African C. loliw 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 Avith large 
pits at apertures of supraorbital foramina of frontals, and generally 
a distinct lachrymal fossa. Molars of upper jaw narrow, -svithout 
inner accessory column, and resembling those of the Sheep and 
Goats. Tail moderate, compressed, hairy above. 

Antilope.^ — Horns, present only in the male, long, cylindrical, 
subspiral, and diverging. Suborbital gland large, vnth. 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. Syn. EUotragxis. 
^ Pallas, Spioilegia Zoologica, vol. i. p. 3 (1767). 



BO VI DM 341 



Jumna which cannot be distinguished from those of the existing 
species. 

JE^yce/ros?- — 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 (^. 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. ^. petersi is 
from the Congo. 

Saiga? — 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, D 13, L 6, S 4, C 10. One 
species. Eastern Europe and Western Asia. 

The Saiga {S. tarfarica) is a clumsily built and somewhat 
sheep-like Antelope inhabiting the steppes ; it occurs fossil in the 
Pleistocene of France and England. 

Pantholops.^ — 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^ — 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 Avith 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 

^ Sundevall, Kongl. Vetensk. Akad. Handl. for 1845, p. 271. 

2 Gray,'iw« Mamm. Brit. Mus. p. 160 (1843). 

3 Hodgson, Proc. Zool. Soc. 1834, p. 81. 

* De Blainville, Bull. Soc. Philoni. 1816, p. 75. Is taken to inalude Frocapra 
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 twenty- 
four existing species, are typically Palaearctic desert forms, the 
Springbok ((?. euclwre) being an outlying South African species. 
G. pidicaudata 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 ^ 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. tilonurci, G. naso. 

2. Horns non-lyrate — G. cuvieri, G. leptoceros, G. spekei, 

G. arabica, G. iennetti, G. fuscifrons, G. muscatensis. 
II. Female without horns. 

G. suhgutturosa, G. gutturosa, G. picticaudata. 

b. White of rump j)rojecting forwards in an angle into the fawn 

colour of the haunches. Horns in both sexes. 

G. dama, G. mohr, G. soemmerringi, G. granti (Fig. 121), 
G. thomsoni. 

B. A white stripe clown the back, two lower premolars. Horns in 

both sexes. — G. euchore. 

The East African G. walleri is an aberrant species, in which the 
females are hornless, which has been made the type of the genus 
Lithocmnius. 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 Gazella are found in the Pliocene and Pleistocene 
deposits of Europe and India. G. deperdita {h-evicorni^), 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 existinc; forms. 

Eippotragine Sediou.—hiclndes 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 mth 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 Hst. 



BO VIDM 343 



Upper molars extremely hypsodont, very broad, and with large 
accessory columns, thus closely resembling those of the Oxen. 
Some 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 orbit 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 {H. 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-ui:) is distinguished by the glaucous hue of the hair. The other 
species are the Equine Antelope {H. equinus) 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 (H. sivalensis), and Sir V. Brooke suggests 
that the European Pliocene Antilope redicoriiis is not generically 
separable. 

Ori/x.- — Horns long, slender, nearly straight or somewhat 
recurved, rising behind the orljit, 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 liase of the horns. The head otherwise is white, as also are 
the limbs, mth the exception of the thighs, which are black. 
The Gemsbok generally goes in pairs, or in small herds of three 
or fom\ The Beisa (0. bdsa) of Abyssinia is distinguished bj'' 
the absence of the tuft of hair on the throat. Writing of this 

1 Sundevall, Kongl. Trfok*. Akad. Hand/, for 1844, p. 196. 
= De Blaiuville, Bull. Soc. Phi/om. 1816, p. 75. 



344 



UNGULATA 



species in his Geology and Zoology of Alyssinia, 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 walk or a 
trot ; they rarely break into a gallop unless greatly alarmed. 
When frightened they dash off, sometimes snorting and putting 







Fig. 141. — The Gemsbok {Oryx gazejla). 

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. beairix) is a much 
smaller animal, with the black markings confined to the head, fore 
limbs, and flanks. Finally, the Leucoryx (0. leucoii/.r) of North 
Africa, while agreeing in size with the Beatrix, differs by its cm-ved 
horns and uniform coloration. 

The extinct Falamip; of the Lower Pliocene of Europe and the 
Isle of Samos, appears to have been an ancestral form of 0;//,r, said 
to show some signs of affinity with Hippotraiius. 



BOVIDJS 345 



Addax} — Horns with the same inclination as in Oryx, but with 
a slight spiral twist. No mane on nape, but a slight one on the 
throat. Hoofs rounded. One species {A. nasomaculatus), 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 
outwards from the base of the horn. Skull without lachrymal 
fossa, but with a large or small lachrymal fissure ; usually large 
pits at the apertures of the supraorbital foramina on the frontals ; 
premaxillse reaching nasals. Mufile large and moist ; nostrils 
approximated. Molars hypsodont or brachydont. Vertical white 
stripes frequently present on the body. 

a. Hind limbs much shorter than the fore. Horns behind the orbit, 

.sliort, conical, faintly angulated. Nose bovine. Body without 
vertical stripes. Molars (Fig. 123, p. 311) hypsodont, with 
a large accessory column in those of the upper jaw. One 
Oriental genus. 
Boselccphus.^ — The one genus of this subsection is represented 
only by the well-known Nilghai {B. tragocainelus) 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 difierent 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 Eafinesque, Anal. Nat. 1815, p. 56. 

^ De Blainville, Bull. Soc. Philom. 1816, p. 75. Syn. Portax, Hamilton- 
Smith. 



346 



UNCULATA 



generally striped. Molars hrachydont, those of the 
upper jaw in existing forms with a small inner accessory 
column. Three existing Ethiopian genera. 
Tragelaphus.'^ — Female hornless. Horns of males (Fig. 142) over 




Fig. 142.— Head of Tragelaplms gratus. From Sclater, Proe. Zool. Soe. 1S83, p. 36. 

orbit, with one or two spiral turns, obsciirely 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 VID.E 



347 



The Harnessed Antelopes are among the handsomest of the 
whole group. The small Guib {T. scriptus) is not larger than a 
Goat, but T. angasi is 3 feet 4 inches in height at the shoulder. In 
T. scriptus, T. .angasi, and 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, back, and belly. 
1\ gratus agrees with this group in coloration (the mane being 




Pig. 143.— The Kudu (Strepsiceros kudu). From Sclater, List of Animals in Zoological Society's 
Gardens, 1888, p. 136. 

absent), but differs in the extreme elongation of its hoofs. The 
Nakong, T. spekei, while having the long hoofs of T. gratus, 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. 1 43) more twisted 
than in Tragelaplms, forming an open spiral, with the anterior ridge 
1 Gray, List. 3Iamm. Brit. Mits. 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. hulu, 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.'^ — Females horned. Horns tmsted 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 favm colour, Avhile 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 Tyjjes.— 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, Palmm-eas, which occurs in the Lower Pliocene of Europe 
and Algeria, appears to present affinities both to Orcas 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 tortkornis, of the French Pliocene 
1 Desmarest, Mammaloijie, p. 471 (1822). 



BOVID^ 349 



resembles Tragelwphus in the greater development of the posterior 
as compared with the anterior ridge of the horn-cores, and has 
accordingly been referred to that genus. Protragelaphus, 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 this 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 Pakeotragine 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 ; 
Palmotragoceros 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 Oriotherium, 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. 

Bicpicapiine 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. 

Rupicapra} — Horns short and cylindrical, rising perpendicularly 
from the forehead for some distance, then bending sharply back- 
wards and downwards, forming hooks with pointed tips. Premaxillee 
not reaching the nasals. One species, Palsearctic. 

The Gemse, or Alpine Chamois {R. 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, vdth 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. PMlom. 1816, p. 75. 



35° 



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.— WemoriiOJciMS crispus. From Solater, List of Animals in Zoological Society's Gardens, 

1883, p. 151. 

each other that often end fatally. The period of gestation is 
twenty weeks, when the female, beneath the shelter of a projectino- 
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.^ — 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 premaxillee 
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 



to Formosa, the ^Malay Peninsula, and Sumatra. The smallest 
species is the Himalayan Goral {K. goral). Of the larger forms ^ye 
may mention the Himalaj'an Serow {X. hubaUnUi<) the Cambing- 
XJtan (-V. sumafreiisi^) of Sumatra, and the Japanese -V. crispits 
(Fig. Hi). Of the Serow, Colonel Kinloch remai-ks that "it 
is a large and powerful beast. The body is covered irith 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 coloui- 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 
do^^^l steep hills. It is a solitary animal, and nowhere numerous." 

Haploceios.^ — The Eocky-3Iountain Goat {Haj-iIocer(X< moiitaints), 
inhabiting the northern parts of California, appears to be very 
closely allied to Xcmorhtedtis. The horns are somewhat compressed 
at the base ; there is no suborbital gland ; and the ears are small. 
The hail-, 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 lai-ge Sheep. 

Budorcds.- — The Takin {£. ttuicolor) of the Mishmi Hills in 
Assam, and an aUied species from Eastern Tibet, are larger forms 
apparently related to Xcmorh<niu-s, but with, a much greater develop- 
ment of the horns. The horns of what is considered to be the 
male ^ arise from the vertex of the skull, and are nearly in con- 
tact in the middle Une; they first bend outwards and downwards, 
and then suddenly upwards and backwards. Those regarded by 
31r. Hume as referable to the female are directed at first outwards, 
and then gradually curve upwards and backwards, ■without any down- 
wai-d rtexure or angidation. The horns of the male may be 2 feet in 
length, ■\\'ith a basal diameter of 1 3 inches. The muzzle is hairy, with 
a small naked mufile. 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 kno^Ti of the habits of the Takin, which 
ne\'er appears to have been seen aUve by Europeans. 

Cajirini' Section. — Both sexes ivith horns, but those of the female 
small. Horns usually compressed, triangidar, with transverse 
ridges, and either cm-%-ing backwards or spiral. Muzzle hairy, 
without naked muffle. Suborbital gland small or absent : lachrymal 

' Hamilton- Smith, iu Gririith's Animal Kingdvui, vol. v. p. 35i (lS2r\ 
Ameuded from " Aplocerus." 

- Hodgson, Journ. As. Soc. Bengal, vol. xix. p. 65 (15.10). 
■' Soo A. 0. Hume, Prcn: Zool. Siv. ISSr, pp. 4So-4Sc:. 



3S2 



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 




ef^..s;^ 



Fig. 145.— The Alpine Ibex (Ca-gra ibex). 

the latest developments of the Bovida', since they are unknown 
before the Pliocene period ; and are essentially mountain forms. 

C'apra.^ — Horns flattened from side to side, and either curing 
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 with a strono- 
odour. Vertebrae: C 7, D 13, L 6, S 4, C 9-13. Some dozen species^ 
ranging over all the higher mountains of Southern Em-ope, 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. Kiit. 12tli ed. vol. i. p. 94 (1766). 



BOVIDjE 353 



The Em-opean Ibex or Steinbok (Fig. 145), which may be 
taken as a typical Goat, 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 -H-inter. The 
horns of the male rise in a bold baclnvard sweep from the forehead, 
and are charactei'ised by the strong transverse ridges on the broad 
and flat anterior surface. They are said to be not more than some 
2 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 foUomng list, mainly 
taken from two papers by Mr. Sclater,^ gives the distribution 
of the various species of Goats, with some remarks on their 
peculiarities : — 

(1) C. ihex, confined to the Alps of Switzerland, Savoy, and 
the Tyrol, and now nearly extinct, except where artificially pre- 
served. (2) C. sibiiica, closelj' allied to the preceding, but with 
larger horns, occui-s in the Altai Mountains, and throughout the 
Himalaya from Kashmir to Nipal, and northward towards Turke- 
stan. (3) C. 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. caiiaisica, a A'ery 
distinct species, confined to the Caucasus, where it inhabits the 
western part of the Great Caucasus ; ^^^th thick horns curving 
backwards and outwards in one plane, with the exception of their 
tips, which incline inwards.^ (5) C. pallad is an allied species from 
the Eastern Caucasus, distinguished, among other featui-es, by the 
curvatui'e of the horns, which lie flatter and twist more outward 
from the forehead, mth a greater terminal inward bend. (6) C. 
j-ii/rcnaica-, of the Pn-enees, and the higher ranges of Central Spain, 
Andalusia, and Portugal, is another nearly related species. (7) 
C. a'ffagrus, formerly abundant over the Grecian Ai'chipelago, 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. (S) C. dorau, a Goat from the island of Jura, near Euboja, 
has been described under this name, and is apparenth- nearly allied 

1 Proc. Zoo!. Soc. 1SS6, p. 314 ; and 1SS7, p. 55i. 

- Specimens referred by Dinnik to C. caucasica have been made tlie types of 
another species — C. sei\-rt:iOvi. 

23 



354 UNGULATA 



to C. CBgagrus. (9) C. walie, an apparently well - characterised 
species from the highest ranges of Abyssinia. (10) C. falconeri; 
the Markhoor diifers 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) 0. hylocrius, 
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 we have but little knowledge. Eemains of 
C. pyrenaica 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. sivalensis 
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} — 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 smaU. Foot-glands 
in all the feet. Chin not bearded ; ^ males without a strong odour 
Vertebra: 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 
^ Linn. Syst. Wat. 12tli ed. vol. i. p. 97 (1766). 
= There may be a beard on the throat, as in 0. cydoceros. 



BOVID^ 



widely separated and much larger than the posterior pair. The 
Bharal, 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- 
posterior line. These transitions towards the caprine type are, 
however, not sufficient to support the \iew 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 wild 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. karelini, but, according to 
Mr. W. T. Blanford,^ is not distinct specifically from 0. poli. East^ 
ward and northward is found the ArgaU {0. argali), "\vith a wide and 
not very weU 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 Rocky Mountains and 
adjacent highlands of western 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 Ruminant, 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. 



3S6 



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. nahura), 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. cydoceros of Northern 



^^^-'^ 




Fig. 146.— The Moufflon (0» 



s musimon). 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 Moufiion of Corsica and Sardinia 
(see Pig. 146), believed to have been formerly also a native of 
Spain. In the three latter species the females are hornless. Lastly, 
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 lono- hair 
on the throat, chest, and fore legs. '^ 



BOVW-S 



We thus find that Sheep are essentially inhabitants of high 
mountainous pirts of the world, for dwelling among which their 
wonderful powers of climbing and leaping give them special 
advantages. Xo species freqiient 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 Xorth America, one into Southern Eiu'ope, and one into Xorth 
Africa. Xo wild Sheep exist in any other part of the world, 
ttnless the so-called Musk-Ox of the Ai'ctic 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 wotild be s;tfer to s;\y that no remains that can be with 
certainty referred to the gentis have been met with in the hitherto 
explored true Tertiary beds, which have yielded such abimdant 
modifications of Antelopes and Deer. They are generally con- 
sidered not to be indigenous in the British Isles, btit to have been 
introdticed by man fi-om the East in prehistoric times. A fossil 
Sheep {Oris Mvigni). apparently allied to the Argiih, has, however, 
been described from the so-called Forest-bed of the Xorfolk coast. 

The Sheep was a domestic animal in Asia and Etuope before 
the dawn of history, though quite imknown as such in the X'ew 
World tmtil after the Spanish conqitest. It has now been intro- 
duced by man into almost all parts of the world where settled agri- 
ctilttu-al operations are earned on, but flotuishes especially in the 
temperate regions of both hemispheres. AMiether otu- 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 conjecttu-e. The variations of external 
characters seen in the diflerent domestic breeds are very gieat. 
They are chiefly manifested in the form and number of the horns. 
which may be increased from the normal two to foiu' 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 pecidiar elevation or arching of the 
nas;tl bones in some E;istern races ; in the lengih of the tail, and 
the development of great masses of fat at each side of its root, or 
in the tail itseK ; and in the colotu and quality of the fleece. 

Orihos.^ — This genus is generally considered to be a connecting- 
link between the Caprine and Bovine sections, but should rather 
be regarded as an aberrant fs-pe of the former. Horns of adult 
male rounded, smooth, and closely approximated at their bases, 
where they are depressed and rugose ; ctu-^-ing downwards, and 
then upwards and forwards. ^Muzzle caprine ; no suborbital gland, 
no lachrymal fossii or fisstue in skull ; orbits tubtilar : a large narial 
aperttu-e and very short nas;ils ; premaxUlfe not reaching nasals. 
^ De BkinTille, BuU. $<\: Fhi'cm. ISlci. p. "(>. 



358 



UNGULATA 



Tail short, and molar teeth caprine. One existing and two fossil 
species, Palsearctic and Nearctic. 

The animal commonly known as the Musk-Ox (Ovibos moschatus), 
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 



cfeC*. 









" ' \\*>.. 



J! ^^jMkjm' 




■^ P c T ^'' " '^ 

.YiQ. 147.— Tlie Musk-Ox {Ovibos moschatus). 

observed that, except as regards the osteology, very little is knoivn 
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 ; their 
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 between the nostrils and 
the upper lip is covered with short close hair, as in Sheep and Goats, 
without any trace of the bare muflSe of the Oxen. The gi-eater part 



BOVID^ 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 do'W'Ti, — 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 Grinnell 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 



36o 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'^ 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 vrfthin 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. lonibifrons and 
0. cavifrons) have been described from Pleistocene beds in the 
United States, the one from Kentucky and the other from the 
Arkansas Eiver. 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 Paleearctic, 
Oriental, and Ethiopian regions, with one Nearctic species and an 
outlying and aberrant species in Celebes. 

£os.^ — The whole of the species of Oxen were included by 
Linnreus 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, Bihos, 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 ^^'ide 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. 

^ Zoologist, September 1877. 
= Linn. Syst. Nat. 12th ed. vol. i. p. 98 (1766). 



BOVID^ 



The first group includes the Buffaloes (genus Bubalus), 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 premaxillse reach to the nasals, and 
the vomer is peculiar in being so much ossifled 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 (B. depressicornis) of Celebes, the type of the genus Anoa or 
Probubalus, which has the same cranial structure as in the more 
typical Bufialoes, 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 bvffelus), which has been domesticated over South-East Asia, 
Egypt, and Southern Europe, is, in the Aidld 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 Narbada 
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,'- 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. Soc. 1873, p. 474. 



362 UNGULATA 



B. cciffer 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.i The large northern 
form described as B. ceguinoctialis 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. hachyceros. 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 rugae. 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 premaxillae do not extend 
upwards to reach the nasals. The Bisons (Fig. 148) have the body 
covered with short, crisp, woolly hair, while 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 group is represented by two species — the European and 
the American Bison. The former is the Bos bonasus of Linnreus, 
and is also identical with the Bos bison of Eay. 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. pumilvs by 
the absence of a fringe to the ears, but specimens in the British Museum show 



that this is not the case. 



BO VI D^ 363 



abundant over a large portion of Europe in the Pleistocene period 
— the fossil race described as B. priscus 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,i " 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. 148. — The American Bison (Bos amencanus). After Homaday. 

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 Bail way 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, 
^ 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 Wood-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 




Pig. 149.— The Tak {Bos j 



I, 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, knoAvn 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 flanks ; 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 wearied 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 sivalensis, 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. gaums) 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 
premaxillae 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, however, the large and convex intercornual frontal crest, 
which 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 with on the flat. It is very shy and readily 
frightened ; and it has never been domesticated. The Gayal, or 
Mithan, of which a figure is given in woodcut 150, is at once dis- 
tinguished from the Gaur by the straight line between 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 



1 (Bos frontalis). From Sclater, List of Animals in Zoological 
Society's Gardens, 1883. 



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 palce.ogaums, is believed to indicate 
a species nearly allied to the Gaur, if indeed it be specifically 
'distinct. 



BOVIDJE 367 



The true Oxen, or Taurine group, are now represented solely 
by Bos taurus and Bos 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 premaxillaB 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 Caesar, by whom they were described as the 
Urus, equal to the German Aurochs ; and the large skulls found in 
tiu-bary 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. taurus, of which it has been thought the 
Chillingham cattle are smaller descendants.'- 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. indictis) it is quite 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 premaxillte 
from the nasals. 

The earliest representatives of this group occur in the Pliocene 
of the Siwalik Hills in Northern India. One of these species 
{B. 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. elatus, 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 Leptohos) were 
often or always hornless. The limbs were unusually slender. 
This group also occurs in the Pliocene of the Siwalik Hills. 

^ The late Mr. Alston, Fauna of Scotland, " Mammalia " (Glasgow, 1880), p. 25, 
considers that the Chillingham cattle are descendants of a race which had escaped 
from domestication. 



368 



UNGULATA 



Suhm-der Peeissodactyla 

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. Palaeontological 

ABC 




Fig. 151.— Bones of right fore foot of existing Perissodactyles. A, Tapii- (rapjres tndicus), 
xj; B, Rhinoceros (fiUnoairos sumatrensis), xi; G, Horse (Equus mhcdlus), xj. U, ulna; 
B, radius; c, cuneiform ; I, lunar; s, scaphoid; i(, unciform ; m, magnum ; td, trapezoid- tm' 
trapezium.— From Flower, Osteology of Mammalia. 

records, however, show very clearly that these are but the sm-^^vino■ 
remnants of a very extensive and much -varied assemblao-e 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 



PERISSODACTYLA 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 vertebrae never fewer than 
twenty-two, usually twenty-three in the existing species. Nasal 
bones expanded posteriorly. An alisphenoid canal. Femur with 
a third trochanter.^ 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. 151). 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 pulley-like smface 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, which 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 csecum 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 when 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 
^ "Wanting in the aberrant Clialicotheriuin. 
24 



370 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 aiford much information as to the general structure of 
the members of the suborder. 



Family Tapirid^. 

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, i Outer columns of upper molars conical. Four digits 
in the manus, and three in the pes. 

Tapints.^ — Dentition « f, c i, jj |, m g ; 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 -^vider 
transversely than from before backwards, each ha^'ing four cusps, 
connected by a pair of transverse ridges, anterior and posterior'. 
The first lower premolar compressed in front ; the others composed 
of a simple pair oi 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. 1882, p. 775. 

2 Cuvier, Tableau Aliment, de I'Hist. Nat. p. 152 (1798) ; ex Brisson. 



TAPIRID^ 371 

triangular, and pointed in front. Vertebrae : C 7, D 18, L 5, S 6, 
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 maxillse (genus Elasmognathus, G-ill). 
Two species, both from Central America, Tapirus bairdi and T. dowi. 
The former is found in Mexico, Honduras, Nicaragua, Costa Eioa, 
and Panama ; the latter in Guatemala, Nicaragua, and Costa Eica. 
(B) With ossification of the septum not extending farther forward 
than the nasal bones {Tapirus 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. americanus 
(T. terrestris, Linn.), the common Tapir of the forests and lowlands 
of Brazil and Paraguay (Fig. 152); and T. roulini, 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 when 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 Ijy what is 
known of the geological history of the race ; for the Tapirs must 



372 



UNGULATA 



once have had a very 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. priscus, T. arvernensis, etc., have been 
found in France, Germany, and in the Eed 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 ^vider than at present. 



■^, L,-^.(-X, 







Fio. 152.— The American Tapir (Japirus mneruMnus). 

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 durino- such an 
enormous period of time. 

The anatomy of the soft parts of the Tapirs i conforms to the 

^ See J. Murie, Journ. Anat. and Physiol, vol. vi. p. 131, I871 • W. N" Pai-l-er 
Proc. Zool. Soe. 1882, p. 768 ; and F. E. Beddard, Proc. Zool. Soi 1889,'p. 252 ' 



LOPHIODONTID^ 373 

general Perissodactyle type, as exemplified in the Ehinoceros and 
the Horse, although on the whole (as might have been expected) 
presenting a closer resemblance to the former. T. americaniis 
differs from T. indicus by the absence, or at any rate the less 
development, of the intestinal valvnlae conniventes, the presence 
of a moderator band in the heart, the shape of the glans penis, 
and the more elongated csecum, 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. 

Pakeotapirus. — 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 LoPHiODONTiDiE. 

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 
■vWth 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 Eabbit 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, 
i %, c ]-, p ^, m §, 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. Eyrachyus, 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 PUolophus 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. 163.— Eight side of skull of Hyracotherlnum leporinum, from the London Clay, i natural 
size. (After Owen.) 3, Occiput ; f , sagittal crest ; 11, frontals ; 15, nasals ; 21, maxilla ; 22, 
premaxilla ; d, mandibular condyle ; a, aperture of facial nerve ; p 1-4, premolars ; m 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.^ This 
genus, indeed, so closely connects Hyracotherium with the genera 
Epihippus^ and Jnchilophus as to show that the distinction between 
the LopUodontidcn and Fakeotheriidce is really an arbitrary one. 
EpiUppus, 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 Anchilophns by the lower cusps and more 
imperfect transverse ridges of these teeth. The so-called Orohippus 
agilis belongs to this genus. Isedolophus is another American Eocene 
genus which may be provisionally placed in this family; it is 
regarded by Professors Scott and Osborn as connecting Systemodon 
"■ The Swiss P. sidcrolithicus has only one cusp in the last upper premolar. 



PAL.-EOTHERIIDyE 



375 



with the Tapiridce ; 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^OTHERIID^. 

Molars (Fig. 155) brachydont, with the valleys between the 
ridges never filled with cement ; upper premolars either simpler than 




Pig. 164.— Eestoration of Palmotherium (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 
vnth 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, 
Pakeotherium, was made known to 
science in the early part of the ^^^^^ ^ 

present century by Cuvier, who External surfaces ofouter columns; a, postero- 

restored the skeleton (Fig. 154) external column (metacone); 6 antero-ex^ 

.,, , ^ 1 vi iV ? j: t-U^ temal column (paracone) ; c, postero-internal 

With a short neck like that Ot me ^oju^ (^ypocone) ; d, antero-intemal column 

Tapirs, although it has been sub- (protocone) ; i, anterior intermediate column 

sequently found that the neck (protoconule); e, median valley;;,, posterior 

was considerably longer. This "'' ^^' 

genus (which may be taken to include Paloplotherium) ranges from 




Fig. 156.— a half-worn right upper molar of 
Palccotlurium magmim. (After Owen.) /, /, 



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. Anchilophus, of the Upper Eocene of Europe, 
and Anchitherium, of the Miocene of Europe and North America, 
connect the preceding forms with the Equidce. In the latter genus 
there is the full number of teeth, the last lower molar has almost 
completely lost the third lobe of Anchilophus, 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 Mesohippiis 
and Miohippus) the lateral digits are larger than in the European 
Middle Miocene Anchitherium aurelianense ; 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 EquiDjE. 

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. Digits 
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 Egiddce 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 Phenacodus (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 



EQUID^ 



377 



although one 



species retained a rudiment of the 



(Fig. 156, ci), 
metacarpal of the poUex. 

The transition from these animals of the Eocene period to the 
Horses of modern times has been accompanied by a gradual increase 
in size. The diminutive Hyracoiherium of the Lower, and Pachy- 
iiolophus of the Middle and Upper Eocene were succeeded in the 
Miocene period by the forms to which the name of Anehitherium 
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 Equidce occur which 
approach in size the existing Horse. Important structural modi- 
fications have also taken place, with corresponding changes in the 




Fig. 156.— 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 (iii). a, PacJiynoloijlitis (Eocene) ; 6, Anehitherium (Early Miocene) ; c, Aiichitheriwni 
(Late Miocene) ; d, Ilipparion (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 require 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 



378 



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 ciu'ious 
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 AncMihirmm ; &, 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 filling the 
cavities and 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 



EQUID^ 



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 cro^vn continued lengthening 
until in the modern Horses it has assumed the form called " hyps- 
odont" (Fig. 158, h). Instead of contracting into a neck, and 
forming roots, its sides continue parallel for a considerable depth in 
the 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 Rodent'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 
place to find their sustenance among the 
comparatively dry and harsh herbage 
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 fan fasmi 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 weight 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, while 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 whole weight of the 
body and all the muscular power are concentrated, give them speed 



Fig. 158. — a, Outer view of second 
upper molar tooth of AnchUherium 
(brachydont form) ; &, corresponding 
tooth of Horse (hypsodont form). 



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. 

FrotoMppus.^ — In this Lower Pliocene North American genus 
(also described as Merychippus) the cheek-teeth resemble those of 
the generalised species of Eguus, but have shorter crowns ; while 
the milk-molars approximate to the permanent molars of Anchi- 
therium. Each foot has three digits. 

Hipparion.^ — Upper cheek-teeth (Fig. 159), with the antero- 




c f d i 

Fig. 169.— Three right upper cheek-teeth of Hippanon. a, Antero-external column; b, 
postero-external column ; o, postero-internal column, or posterior pillar ; d, antero-internal 
column, or anterior pillar ; /, posterior intermediate column ; i, anterior intermediate column. 
(From the Palceontologia Indica,) 

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 Leidy, Proe. Ac. Nat. Sci. Philad. 1858, p. 26. 
^ Christol, Ann. Sci. Indust. Mid. France, vol. i. p. 180 (1832). 



EQUID^ 381 

of North America, there were three digits in the feet (Fig. 156, d); 
but in the Indian H. antilopmum (separated by Cope as Eirppo- 
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 Eqims 
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 with a single complete 
digit, but mth remnants of the proximal portions of the second 
and fourth metapodials (Fig. 156, e) ; some extinct forms having 
claw-like 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 
North America for which the name Pliohippus 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 siirface of the anterior pillar 
of the upper molars. In one of the species from the Lower 
Pliocene of India {E. sivalensis) — 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 Equidce in 
America, their complete extinction, and their perfect acclimatisation 
1 Linn. St/sL Nat. 12th ed. vol. i. p. 100 (1766). 



382 UNGULATA 



when reintroduced by man, form curious but as yet unsolved 
problems in geogi-aphical distribution. 

Existing Species. — The existing species of the genus are the 
following : — 

The Horse, JEquus caballus, is distinguished from the others by 
the long hairs of the tail being more abundant and growing quite 
from the baise 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 mid Horses were extremely abundant in the 
Neolithic 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 Donwstication, 1868, vol. 
i. chap. ii. 



EQUIDJE 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 Horse from Central Asia, named E. pxzevalskii,^ 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. caballus 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. asinus), and the wild 
Asses of Africa {E. asinus, var. afrkanus and var. somalicus ^). 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 frequently banded. 
Of the wild forms the Nubian race (var. afrkanus) 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 ^ {E. hemionus), they present such marked variations in size 
and form that they have commonly been divided into three — the 
Syrian Wild Ass (E. liemippus), 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 

^ See Nature, 21st August 1884, and Zool. Garten, vol. xxviii. p. 453. 
2 See Sclater, Froc. Zool. Soc. 1884, p. 542. 

* See Blanford, Zoology and Geology of Eastern Persia (Journeys of the Persian 
Boundary Oommission), p. 84. 



384 



UNGULATA 



either of the others, and differs from them in external appearance, 
having more the aspect of the horse. They are all remai'kaljly 
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 was 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 




Fia. leo.— The Quagga (Eijuus quatjoa). 

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^ 



38s 



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 BurcheU's Zebra. 

Of the Zebras proper, the one which was iirst known to Europeans, 
and was formerly considered the most common, is the True Zebra 
(E. 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. 161. — True or Mountain Zebra (Efjuus zebra). 

become very scarce, and is even, like the Quagga, threatened with 
extermination at no distant date. The second species, BurcheU's 
Zebra (£. bmxhelli), still roams \n large herds over the plains to the 
north of the Orange Eiver, but in yearly diminishing numbers. 
Both species are subject to considerable individual variations in 
marking, but the following are the principal characters by which 
they can be distinguished. 

B. zebra (Fig. 161) is the smaller of the two (about 4 feet high 
at the shoulders), and has longer ears, a taU more scantily clothed 
Avith 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 



386 



UXGULATA 



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 taU. There is often 
a median longitudinal stripe under the chest. 







Fig. 162.— Burchell's Zebra (Equus Imrcheai). 

E. lurclielU (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 nearlv 
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. chipmani). There is a strongly marked median lon^ntudinal 
ventral black stripe, to which the lower ends of the transverse side 
stripes are usuaUy 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 \ride intervals between the broad 



EQUIDyE 387 

black stripes of tie flanks and haunches fainter stripes are generally 
seen. 

E. grevyi. — Under this name a Zebra has been described which 
Tvas sent in 1 882 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 sufiicient 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 
Biu'cheU'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, which 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 piu-e species, it is 
doubtful if any case has occiured 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 ofispring 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 



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, 
whose 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 ivith 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 we have 
examined bear little resemblance to those of Hipparion or Anclii- 
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, 



EQUID^ 



389 



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 



PMi, 




Fig. 163. — Side view of skull of Horse, with the bone removed so as to expose the whole of 
the teeth. VMx, Premaxilla ; Ux, maxilla ; li^a, nasal ; Ma, malar or jiigal ; i, lachrymal ; Ft, 
frontal ; Sg, squamosal ; Pa, parietal ; OG, occipital condyle ; ^"p, paroccipital process ; ii, i2, 
and i3, the three incisors ; c, the canine ; pwii, the situation of the rudimentary first premolar, 
which has heen lost in the lower, but is present in the upper jaw ; pm2, p7rt3, and pm4, the 
three fully developed premolars ; m^, m2, and m3, 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 



390 UNGULATA 



forms part of the posterior and inferior boundary of the orbit, an 
arrangement not met mth in other mammals. The closure of the 
orbit behind distinguishes the skull of the Horse from that of the 
Ehinoceros 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 premaxillae. 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 maxillae, 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 gi-eatly 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 other-s\Tise loose tympano- 
periotic bone. Behind this the exocoipital 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 laro-e 



EQUID^ 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 sends 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 Ehinoceros. 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 
symphysis, 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 vertebrae. 
There may be nineteen rib-bearing vertebrae, 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 Euminants. The bodies of the cervical vertebrae are elon- 
gated, strongly keeled, and markedly opisthocoelous, or concave 
behind and convex in front. Their neural laminae are very broad, 
the spines almost obsolete, except in the seventh, and the trans- 
verse processes not largely developed. In the trunk vertebrae the 
opisthocoelous 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 nuchce, or "paxwax," which passing forwards in the 
middle line of the neck above the neural arches of the cervical ver- 
tebrae, to which it is also connected, is attached to the occiput and 
supports the weight of the head. The transverse processes of the 
lumbar vertebrae 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 
vertebrae, 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 roimded, 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 suffraginis, 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 metacarpo-phalangeal articulation, and a single large 
transversely extended sesamoid behind the joint between the 
second and third phalanx, called the " navicular bone." i 

The carpal joint, corresponding to the wrist of man, is commonly 
called the " knee " of the Horse, the joint between 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 lower part beino- 
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^ 



393 



but 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 
bones 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 ^ of the limbs are modified from those of the ordi- 
nary mammalian type in accordance with the reduced condition of 
the bones and 
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- 
form 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 extensw communis 
digitorum of the arm and extensor longus digiiorum 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 

^ 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 (fts suffraginis) ; 3, second phalanx (os coronce) ; 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 ; S, tendon of superficial fiexor (Jl. perforatus) ; 
9, tendon of deep flexor (fi. perforans) ; 10, suspensory ligament of 
fetlock ; ll, inferior or short sesamoid ligament ; 12, derma or slcin 
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 ; 17, hoof ; 18, fatty 
cushion of fetlock. 



394 UNGULATA 



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 flexm- perforatus 
(8), dividing to allow the other to pass through, and then inserted 
into the middle phalanx. The flexoi' perfwans (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 
(tihialis posticus of man) is united with 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 -^nthin 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 papillae or laminse. From 
this the horny material which constitutes the hoof is exuded. A 



EQUIDJE 395 

thickened ring encircling the upper part, called coronary cushion 
(13), and the sole (15), 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, vidth 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 papillae of the keratogenous membrane, 
so that a section near the base of the hoof, cut transversely to the 
long axis of these papillse, 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," gi'owing like the hoof from enlarged papillae of the skin, are 
found on the inner face of the fore limb, above the carpal joint, in 
all species of Equiia, 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^, c \, p ^, 
m I = 42. The incisors of each jaw are placed in close contact, 
forming a semicircle. The crowns are broad, somewhat awl- 
shaped, and of nearly equal 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 which 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 efiiciency 
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. 165.— Longitudinal and transverse section of upper quite rudimentary, often 

incisor of Horse, ft Pulp cavity ; d, dentine or ivory ; e, p^rippiallv in tTio l^wo^ 

enamel ;c, outer layer of cement ;c', inner layer of cement! ?®P^°^^^^y ^^ tjie lower 

lining a, the pit or cavity of the crown of the tooth. ]3''^j not developed at all, 

and generally fall by the 
time the animal attains maturity, so that there are but six func- 
tiona,! 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 away;— 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 deiinite 
pattern, which give it great efficiency as a grinding instrument (see 
Fig. 157, & and c). The free surfaces of the upper teeth are 




EQUIDAZ 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^, in f = 24, — the canines 
and first or rvidimentary 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 liefore the end of the second year. At 
iibout 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 foiu 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. 

JVg(vtiir Organs. — The lips are fiexible and prehensile. The 
membrane that lines them and the cheeks is quite smooth. The 
palate is long and narrow; its mucous surface has seventeen pairs 
of not xovy sharply defined oblique ridges, extending as far Ixick as 
the last molar tooth, beyond which the \elum palati extends for 
about 3 inches, having a soft corrugated sm-face, and ending 
posteriorly in an arched border without uvula. This embraces the 
base of the epiglottis, and shuts oft" all communication between 
the ca\-it_y of the mouth and the nasal passages, respiration 
being, under ordinary circumstances, carried on exclusively 
through the nostrils. Between the mucous membrane and 
the bone of the hard palate is a dense vascular and nervous 
jilexus. The membrane lining the fauces is soft and corrugated. 
An elongated raised glandular mass, 3 inches long and 1 inch from 



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 papillas 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 e