I have not attempted to write a complete synonymy of the species of Monkeys. The literature is scattered over many, often obscure, periodicals, and without seeing the actual specimens described by some of the older writers, it would be easy to introduce a great deal of confusion into the synonymy. I have, therefore, only attempted to give the principal references.

I must express my obligation to Dr. Günther, F.R.S., the Keeper of the Zoological Department in the British Museum, for the facilities of study afforded to me in that institution. To Mr. Oldfield Thomas I am likewise greatly indebted for much assistance, and for many a kindly hint.

Dr. Forsyth Major, who is well-known as one of the foremost authorities on the Lemurs, not only gave me valuable information as to the species and literature of the Lemuroidea, but was even so good as to furnish me with the descriptions of several new species.

Lastly, to my friend the Editor, I have to return my sincere thanks for the patience with which he has revised my MSS., and for the verification of numbers of references, only to be found in the great libraries of London, and inaccessible to an author dwelling in the provinces.

HENRY O. FORBES.

SYSTEMATIC INDEX.

PAGE
ORDER PRIMATES[1]
SUB-ORDER I. LEMUROIDEA[8]
FAMILY I. CHIROMYIDÆ[14]
I. Chiromys, Cuvier[14]
01. madagascariensis (Gm.)[14]
FAMILY II. TARSIIDÆ[18]
I. Tarsius, Storr.[18]
01. tarsius (Erxl.)[20], [286]
02. fuscus, Fischer[21]
FAMILY III. LEMURIDÆ[22]
SUB-FAMILY I. LORISINÆ[24]
I. Perodicticus, Bennett[26]
01. calabarensis, Smith[27]
02. potto (Geoffr.)[28]
II. Loris, Geoffr.[31]
01. gracilis, Geoffr.[31]
III. Nycticebus, Geoffr.[33]
01. tardigradus (Linn.)[33], [286]
SUB-FAMILY II. GALAGINÆ[37]
I. Galago, Geoffr.[38]
01. garnetti (Ogilby)[40]
02. senegalensis, Geoffr.[41]
03. alleni, Waterh.[43]
04. demidoffi, Fischer[44]
05. monteiri, Bartlett[46]
06. crassicaudata, Geoffr.[47]
II. Chirogale, Geoffr.[49]
01. milii, Geoffr.[50]
02. melanotis, Forsyth Major[51]
03. trichotis, Günth.[52]
04. crossleyi, Grandid.[53]
III. Microcebus, Geoffr.[54]
01. minor (Gray)[55]
02. myoxinus, Peters[56]
03. smithii (Gray)[57]
04. furcifer (Blainv.)[59]
05. coquereli (Grandid.)[60]
IV. Opolemur, Gray [61]
01. samati (Grandid.)[62]
02. thomasi, Forsyth Major[63]
SUB-FAMILY III. LEMURINÆ[64]
I. Lemur, Linn.[65]
01. varius, Is. Geoffr.[68]
02. macaco, Linn.[69]
03. mongoz, Linn.[71]
α. rufipes[72]
β. rufifrons[72]
γ. cinereiceps[72]
δ. collaris[72]
ε. rufus[73]
ζ. nigrifrons[73]
η. albifrons[73]
04. nigerrimus, Scl.[73]
05. albimanus, Is. Geoffr.[74]
06. coronatus, Gray[75]
07. rubriventer, Is. Geoffr.[76]
08. catta, Linn.[76]
II. Mixocebus, Peters[78]
01. caniceps, Peters[78]
III. Hapalemur, Is. Geoffr.[79]
01. griseus (Geoffr.)[81]
02. simus, Gray[82]
IV. Lepidolemur, Is. Geoffr.[83]
Section A.—Species Majores.
01. mustelinus, Is. Geoffr.[86]
02. ruficaudatus, Grandid.[86]
03. edwardsi, Forsyth Major[87]
04. microdon, Forsyth Major[88]
Section B.—Species Minores.
05. globiceps, Forsyth Major[89]
06. grandidieri, Forsyth Major[89]
07. leucopus, Forsyth Major[89]
SUB-FAMILY IV. INDRISINÆ[90]
I. Avahis, Jourdan[94]
01. laniger (Gm.)[94]
II. Propithecus, Bennett [96]
01. diadema, Bennett[98]
α. sericeus[99]
β. edwardsi[99]
02. verreauxi, Grandid.[100]
α. deckeni[101]
β. coquereli[102]
02a. majori, Rothschild[286]
03. coronatus, Milne-Edwards[102]
III. Indris, Cuv. et Geoffr.[105]
01. brevicaudatus, Geoffr.[105]
EXTINCT LEMUROIDEA[110]
FAMILY I. MEGALADAPIDÆ[112]
01. Megaladapis, Forsyth Major[112]
FAMILY LEMURIDÆ[22], [114]
FAMILY ANAPTOMORPHIDÆ[114]
01. Microchærus, Wood[115]
02. Mixodectes, Cope[116]
03. Cynodontomys, Cope[116]
04. Omomys, Leidy[117]
05. Anaptomorphus, Cope[117]
FAMILY ADAPIDÆ[119]
01. Adapis, Cuvier[120]
02. Tomitherium, Cope[120]
03. Laopithecus, Marsh[121]
04. Pelycodus, Cope[121]
05. Microsyops, Leidy[122]
06. Hyopsodus, Leidy[123]
SUB-ORDER II.—ANTHROPOIDEA [123]
FAMILY I. HAPALIDÆ[129]
I. Hapale, Illig.[131]
01. jacchus (Linn.)[132]
02. humeralifer, Geoffr.[133]
03. aurita (Geoffr.)[133]
04. leucopus, Günther[134]
05. chrysoleuca, Wagn.[135]
06. pygmæa (Spix)[135]
07. melanura (Geoffr.)[136]
II. Midas, Geoffr. [138]
01. rosalia (Linn.)[138]
02. geoffroyi (Pucher.)[139]
03. œdipus (Linn.)[140]
04. labiatus, Geoffr.[141]
05. rufiventer, Gray[142]
α. mystax, Spix[142]
β. pileatus, Is. Geoffr.[143]
06. weddelli, Deville[143]
07. nigrifrons, Geoffr.[143]
08. fuscicollis, Spix[144]
09. chrysopygus (Wagner)[144]
10. nigricollis, Spix[145]
11. illigeri (Pucher.)[145]
12. bicolor, Spix[147]
13. midas (Linn.)[148]
14. ursulus, Geoffr.[148]
FAMILY II. CEBIDÆ[150]
SUB-FAMILY I. NYCTIPITHECINÆ[152]
I. Chrysothrix, Kaup[152]
01. usta (Is. Geoffr.)[154]
02. entomophaga (d'Orb.)[155]
03. sciurea (Linn.)[156]
04. œrstedi, Reinh.[158]
II. Callithrix, Geoffr.[158]
01. torquata (Hoffm.)[159]
02. cuprea, Spix[160]
03. amicta (Humb.)[161]
04. cinerascens, Spix[161]
05. moloch (Hoffm.)[162]
06. ornata, Gray[162]
07. personata, Geoffr.[163]
08. nigrifrons, Spix[164]
09. castaneiventris, Gray[164]
10. melanochir, Neuwied[165]
11. gigot, Spix[165]
III. Nyctipithecus, Spix[166]
01. trivirgatus (Humb.)[168]
02. lemurinus, Is. Geoffr.[168]
03. rufipes, Sclater [169]
04. azaræ (Humb.)[170]
05. felinus, Spix[170]
SUB-FAMILY II. PITHECIINÆ[173]
I. Brachyurus, Spix[174]
01. melanocephalus (Humb.)[175]
02. rubicundus, Is. Geoffr.[176]
03. calvus, Is. Geoffr.[177]
II. Pithecia, Geoffr.[182]
01. monachus, Humb. and Bonpl.[182]
02. pithecia (Linn.)[185]
03. satanas (Hoffm.)[186]
04. chiropotes (Humb.)[187]
05. albinasa, Is. Geoffr.[188]
SUB-FAMILY MYCETINÆ[189]
I. Alouatta, Lacép.[192]
01. seniculus, Linn.[192]
02. nigra (Geoffr.)[195]
03. beelzebul (L.)[197]
04. ursina (Humb.)[198]
05. villosa (Gray)[199]
06. palliata (Gray)[202]
SUB-FAMILY CEBINÆ[204]
I. Cebus, Erxl.[204]
01. hypoleucus (Humb.)[207]
02. lunatus, F. Cuv.[208]
03. flavus, Geoffr.[208]
04. monachus, F. Cuv.[209]
05. fatuellus (Linn.)[211]
06. variegatus, Geoffr.[211]
07. cirrifer, Geoffr.[212]
08. robustus, Kuhl.[212]
09. annellatus, Gray[213]
10. albifrons (Humb.)[213]
11. capucinus (Linn.)[215]
12. vellerosus, Is. Geoffr.[217]
13. flavescens, Gray[217]
14. chrysopus, F. Cuv.[218]
15. subcristatus, Gray [218]
16. capillatus, Gray[219]
17. azaræ, Rennger[219]
18. fallax, Schl.[220]
II. Lagothrix, Geoffr.[220]
01. lagothrix (Humb.)[222]
02. infumatus (Spix)[223]
III. Brachyteles, Spix[224]
01. arachnoides (Geoffr.)[226]
IV. Ateles, Geoffr.[227]
01. variegatus, Wagner[231]
02. geoffroyi, Kuhl[233]
03. rufiventris, Scl.[236]
04. paniscus (Linn.)[237]
05. marginatus, Kuhl[239]
06. ater, F. Cuv.[241]
07. grisescens, Gray[242]
08. fusciceps, Gray[242]
09. cucullatus, Gray[243]
10. vellerosus, Gray[244]
FAMILY CERCOPITHECIDÆ[249]
SUB-FAMILY CERCOPITHECINÆ[252]
I. Papio, Erxl.[253]
01. maimon (Linn.)[258]
02. leucophæus (F. Cuv.)[260]
03. doguera (Pucher. and Schimp.)[262]
04. porcarius (Bodd.)[263]
05. babouin (Desm.)[265]
06. anubis (F. Cuv. and Geoffr.)[266]
07. thoth (Ogilby)[268]
08. ibeanus, Thomas[269]
09. sphynx (Geoffr.)[269]
10. hamadryas (Linn.)[272]
11. langheldi, Matschie[275]
II. Theropithecus, Is. Geoffr.[276]
01. gelada (Rüpp.)[276]
02. obscurus, Hengl.[278]
III. Cynopithecus, Is. Geoffr.[280]
01. niger (Desm.)[281]

LIST OF PLATES.

[I.]—Aye-AyeChiromys madagascariensis.
[II.]—Spectral TarsierTarsius tarsius.
[III.]—Javan Slow-LorisNycticebus tardigradus.
[IV.]—Allen's GalagoGalago alleni.
[V.]—Black-eared Mouse-LemurChirogale melanotis.
[VI.]—Smith's Dwarf-LemurMicrocebus smithii.
[VII.]—Red-ruffed LemurLemur ruber.
[VIII.]—Grey Gentle-LemurHapalemur griseus.
[IX.]—White-footed Sportive-LemurLepidolemur leucopus.
[X.]—Woolly AvahiAvahis laniger.
[XI.]—Coquerel's SifakaPropithecus coquereli.
[XII.]—EndrinaIndris brevicaudatus.
[XIII.]—Geoffroy's TamarinMidas geoffroyi.
[XIV.]—Red TitiCallithrix cuprea.
[XV.]—Red-footed Douroucouli or Night-MonkeyNyctipithecus rufipes.
[XVI.]—Bald UakariBrachyurus calvus.
[XVII.]—White-nosed SakiPithecia albinasa.
[XVIII.]—Red HowlerAlouatta senicula.
[XIX.]—Smooth-headed CapuchinCebus monachus.
[XX.]—Humboldt's Woolly-MonkeyLagothrix lagothrix.
[XXI.]—Variegated Spider-MonkeyAteles variegatus.
[XXII.]—DrillPapio leucophæus.

ALLEN'S NATURALIST'S LIBRARY.