328 Prof. W. H. Flower on Extinct Lemurlna. 



1872, in which year Professor Marsh* and Professor Cope f 

 almost simultaneously announced the fact. Since that time 

 as many as fifteen genera have been assigned to the group, 

 including five previously described by Leidy from teeth alone 

 as being of uncertain position. These are nearly all from 

 Eocene formations, though two have been found in the lower 

 Miocene. 



Until we receive fuller information and figures or casts of 

 the remains of these animals, it is premature to speculate upon 

 their real characters or affinities. The difficulty of doing so 

 at present is enhanced by their describers, in the provisional 

 accounts already given, adopting the old assumption that 

 Lemurs and Monkeys are very nearly related, and speaking of 

 them sometimes as one and sometimes as the other. Of course 

 it is possiljle that these animals or some of them may have 

 been Monkeys, in which case they were not Lemurs ; or they 

 may have been Lemurs, in which case they were not Monkeys \. 

 It is possible also that they may form the connecting link be- 

 tween the two, and so justify their old association in one group. 

 Looking at their geographical position, we should be more in- 

 clined to regard them rather as the ancestral forms of the 

 present American monkeys, or perhaps of all the Simn7ia, 

 since there seems great reason now to believe that North 

 America was in those days a great region of development, in 

 which arose many of the forms which spread at a later j^eriod 

 over the Old World. In this case the Lemurs, which, judging 

 from their present distribution, appear to have spread east and 

 west from Madagascar, or the hypothetical submerged continent 

 " Lemuria," may have had quite a different origin. 



The question can only be determined by a rigid and unbiased 

 comparison of the remains, when sufficient materials have 

 accumulated, and is without doubt one well worthy of the 

 devotion of any amount of patience and labour which may 

 be bestowed upon it. 



* Am. .lourn. Sci. & Arts, vol. v. p. 405, Nov. 1872. 



t Proc. Amer. Philos. Soc. 1872, p. 554. See also Cope, "On the Pri- 

 mitive types of the cn-ders of the Mammalia Educabilia,'' Am. Philos. 

 Soc. April 18, 1873; and Marsh, Am. Jouru. Sci. & Arts, vol. ix., March 

 1875. 



X Prof. Marsh expressly states, " From numerous specimens the writer 

 has ascertained that the Limnotheridee should be placed in the Prosiniiae. 

 The brain was nearly smooth, and the cerebellum large and placed mainly 

 behind the cerebrum. The orbits are open behind, and the lachrymal 

 foramen is outside the orbit." The last-mentioned character is certainly 

 specially Lemurine, though the others are common to the early types of 

 mammals, and widelv different from those of modern monkeys. 



