512 ANATOMY OF VERTEBEATES. 



of the Aye-aye to gain a majority against keeping Cheiromys 

 amongst the mice. The singular group of Lemuricloe, which, from 

 the superior brain-development, especially the posterior extension 

 of the cerebrum over the cerebellum, I associate with the Gyren- 

 cephala,^ and by the hinder thumb with the Quadimmana, offers 

 great diversity in dentition and minor characters. 



A. Vertebral Column. — All Quadrumana have the seven cer- 

 vical vertebra?. In the Lemurine or Strepsirrhime group the 

 folio wins; are the numbers of the other vertebras : — 



The majority, including the type-form, of the LemuridcB thus 

 have 19 dorso-lumbar vertebras: the slow nocturnal species have 

 longer and less flexible trunks, approaching in tlie number of 

 dorso-lumbars — 24 — to the vertebral characters of the lissence- 

 phalous Sloths. The tail is, as usual, the seat of the greatest 

 diversity ; the slow lemurs, again, in the shortness of this terminal 

 appendage, recal a bradypodal character. In Stenops gracilis a 

 metapophysial tubercle is developed on each of the twelve anterior 

 dorsals : on the thirteenth it takes the place of the diapophysis, 

 and in the fourteenth extends forward, and offers an articular sur- 

 face for the outer side of the postzygapophysis : it has the same 

 disposition in the lumbar series, Avhere the diapophyses are serial 

 repetitions of the base supporting the anchylosed rib in the first 

 lumbar vertebra. The succeeding lumbars slightly decrease in 

 size as they approach the sacrum. Xo centre of motion of the 

 trunk is indicated by the direction of the dorso-lumbar neural 

 spines. In the more active and flexible-bodied Lemuridce the 

 trunk-vertebras resemble in proportions, connections, and direc- 

 tion of neural spines those of the agile Carnivora. In Lemur 



' See CI*, p. 8, pi. xi. figs. 6, 7. The extension of the ccrebelhim over more 

 or less of tlie cerebrum is the primary and more constant character of the group 

 called, from the secondary character of convolutions, ' Gyrencephala.' The smooth 

 brain of the small jMonkey {Midas rufimanus) is figured in lxiv. to illustrate such 

 primary character. To bo consistent, INIr, Murray would have to remove the JNIar- 

 mosets as well as the Galagos to the Inscctivora; ci.* pp. 9 and 10. 



