IBMUBID^. 43 



Suborder LEMUROIBEA, 



The Lemurs or Half-Apes, Prosimice of some authors, differ so 

 widely from the Monkeys, both externally and anatomically, as to 

 have been classed by many naturalists in a distinct order. The 

 principal distinctions are the form of the skull and teetb, the 

 greater extent to which the cerebellum is uncovered by the cere- 

 brum, the greater development of the poUex, and the long claw- 

 shaped nail on the second digit of the foot in Lemurs, and the 

 presence in these animals of a perforate clitoris, a two-horned 

 uterus, and a bell-shaped, diffuse, and non-deciduate placenta. 

 The skull in Lemurs has a long narrow muzzle ; the orbits are not 

 surrounded by bone behind, as in Monkeys, but open freely 

 beneath the bony orbit into the temporal fossa ; and the lachrymal 

 foramen, instead of being internal, opens on the outside of the 

 skull. The upper incisors are, in nearly all Lemurs, divided by a 

 toothless interspace in the middle of tlie upper jaw ; and the 

 lower incisors are long, narrow, and projecting ; whilst the lower 

 canines are, in most of the forms, only distinguished from the 

 incisors by greater depth, and have been, by sevei'al writers, 

 counted as incisors. In most species, too, the anterior or first 

 lower premolar is larger than the second and third, and resembles 

 a canine, whilst the other premolars and molars are very different 

 in shape from those in all the Old-World Monkeys (those of the 

 Marmosets are intermediate in form), beiiig more or less ovate in 

 section instead of rectangular. Most of the characters enumerated 

 as distinguishing the Lemurs are found also in other and lower 

 orders of Mammalia. (For additional details on the Lemuroidea, 

 see Mivart, P. Z. S. 1873, p. 503, and ' Encyclopaedia Britannica,' 

 article "Lemur.") 



The Lemuroidea ave divided into three families — Lemuridce, com- 

 prising the greater number of the genera ; Tarsiidce, consisting of 

 a single genus and species, Tarsius spectrum, found in the Malav 

 Archipelago, but not known to occur on the continent of Asia ; 

 and Chiromyidce, also comprising a solitary representative only, the 

 Aye- Aye of Madagascar. The first family is alone represented in 

 South-eastern Asia. 



Family LEMURID^. 



Two genera occur within our area, aU the others are restricted 

 to Africa and Madagascar, the majority being peculiar to the last- 

 named island. The two found in India, Ceylon, and Burma are 

 thus distinguished : — 



