402 GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION. 



archipelagos Sumatra, Java, Borneo. Loris, with a single spe- 

 cies, the graceful loris (L. gracilis), is a native of Ceylon. Two 

 other species of the same sub-family, resembling the last in their 

 habits, but provided with a rudimentary tail, and with a greatly 

 reduced index-finger, inhabit the west coast of Africa : the potto 

 (Perodicticus potto) is a native of the Gaboon region and the ter- 

 ritory of Sierra Leone, and the awantibo (P. [Arctocebus] Calaba- 

 rensis) of Old Calabar. 



The most aberrant form of lemur is the Madagascan aye-aye 

 (Chiromys Madagascariensis), an animal of about the size of a cat, 

 with a rodent-like dentition, and singularly elongated fingers fur- 

 nished with pointed claws. For a long time the position of this 

 remarkable animal was misunderstood, it having been placed alter- 

 nately with the lemurs, insectivores, and rodents. It constitutes 

 the type of a distinct family, Chiromyidae. 



The somewhat anomalous distribution of this group of animals, 

 taken as a whole their headquarters in Madagascar, with a thin- 

 ning out towards the west on the African continent, and their re- 

 appearance in Ceylon and the mainland of Asia has suggested to 

 some naturalists the notion that at a former, and fairly ancient, pe- 

 riod of the earth's history direct land connection existed between 

 these various points, bridging over the chasms that now separate 

 them in the way of water, and permitting of ready migration from 

 one region to another. For this hypothetically assumed, now 

 sunken, continent, Mr. Sclater has proposed the name "Lemuria." 

 In how far such a connecting land-mass may have existed in fact, 

 or in how far, if it actually existed, it was directly concerned with 

 the present distribution of the lemurs, still remains to be deter- 

 mined. 



The earliest lemuroid remains of the Old World are probably 

 those of Ca3nopithecus lemuroides, described by Rutimeyer from 

 the Eocene deposits of Egerkingen, Jura Mountains, and supposed 

 by their discoverer to represent an animal of intermediate relation- 

 ships between the true lemurs and the American monkeys. This 

 form is not unlikely identical with a species described from the 

 gypsum deposits of the Paris Basin and the phosphorites of Quercy 

 (Oligocene) as Adapis Parisiensis for a long time supposed to 

 represent an ungulate with which, also, the Palaeolemur Betillei, 



