AMEGHINO: LA PEBFORACIÓX ASTRAC4 ALTANA. 93 



teralis is never found as a distinct miiscle ontside the order with 

 whicli we are now concerned, whilst the short head of the flexor 

 crnris lateralis is only to be seen in the Edentates, Platyrrhine 

 Monkeys, and Anthropoids. There are other peculiarities common 

 to the two animáis, such as the total absence of fabellae from the 

 gastrocnemius, the occasional presence of a fibular origin for the 

 extensor brevis digitorum pedis, and the absence of the sterno- 

 facialis (sphincter colli) part of the pannicnlus, which are no so 

 strikirig as the former two, but which, taken together, are enough 

 tu make us think that there is a closer kiushiiD between the Sloths 

 and the Pangolins than they are generally supposed to possess. It 

 would be easy to pick ont points of similarity between the Sloths, 

 Ant-eaters, and Armadillos by reason of which they differ from the 

 generalized mammalian type, and which clearl}'^ point to their near 

 relationship with one another; it would also be easy to indicate by 

 means of its museles that, although Manís cannot be a very dis- 

 tant relation of the Bradypodidae, it is more closely allied to the 

 Myrmecophacjidae and Dasypodidae. When we come to consider 

 the Orycteropidae, however, we are more struck with the generali- 

 zed mammalian arrangement of its museles than by any special 

 edentate characteristics; the three points on which welaid somucli 

 stress in claiming a place for the Pangolins in the Edentate order 

 are wanting in the Aard-vark. There is no rectus thoracis lateralis, 

 no femoral head to the flexor cruris lateralis, and it has fabellae 

 in its gastrocnemius just like any other mammal. In addition to 

 this the sterno-facialis, which in all other Edentates is suppressed, 

 is very strongly marked and covers a part of the pectoral as in 

 Erinaceus amongthe Insectívora and Bathyergus amongRodentia. 

 There are, however, a few points in which the Aard-vark differs 

 from most mammals and resembles the Edentata. One of these is 

 the presence of more than one soapular head for the exteusor cu- 

 biti (tríceps), and another is the double tibialis posticus. We have 

 never yet seen either of these arrangements in any other mammais 

 but the Edentates; and we cannot help regarding this animal as a 

 link between the Edentates and the more generalized stock from 

 which that order has diverged. We have read with much interest 

 a paper by Dr. EUiot Smith (Trans. Linn. Soc, 2nd ser. Zool. vo). 

 VII, pt. 7, p. 387) in which he says that "if the brain of Oryctero- 

 ptis were given to an anatomist acquainted with all the other va- 

 riations of the mammalian type of brain, there is probabl}' only 

 one feature which would lead him to hesitate in describing it as an 



