1884.] On the Skull in the Mammalia. 79 



Since then, whilst gathering fresh and fresh mammalian materials, 

 the greater part of my actual work has been on the skull of the other 

 classes. 



There have been two reasons for this : first, the difficulty of 

 obtaining subjects for dissection, and then the fact that the 

 mammalian skull is the most difficult of interpretation, and asks for 

 an interpreter who is quite familiar with that of more simple 

 types. 



Now, I hope to take up Order after Order of this, the highest group 

 of the Vertebrata. Of course this will employ me for many years to 

 come. 



I would, if it were possible, take the lowest types first, namely, the 

 Monotremes or " Prototheria," but this cannot be done. Even the 

 Marsupials or "Metatheria" will have to come after the Insectivora, 

 that is, they will be treated of in the next paper but one. 



I am not of opinion that this irregular way of working has any 

 harm in it ; when once the facts have been gathered and arranged the 

 mind will be able to draw its deductions ; if the garners be but full, a 

 little irregularity in the harvesting will not count for much. 



The materials for the present paper have taken me more than 

 twenty years to collect. Hearty thanks are due to those friends* who 

 have helped me according to their power. 



I have worked out the skull in several embryos of the Armadillos, 

 these belong to two genera and three species. 



In the Bradypodidae (Sloths) I have had two stages of the embryo, 

 and two of the young, these belong to two genera and three species. 



In the Anteater (Cyclnturus') I have worked out the skull in two 

 young specimens ; in the Pangolins (Manida3) in an early and a latter 

 embryo, in the new-born young, and in the adult ; and in Orycteropus 

 in the nearly ripe embryo. 



I now offer, in the main paper, the results of this piece of research ; 

 this has not been done, however, until much more of the same kind 

 of work has been either finished or got well in hand, as I am 

 anxious for the structure of the skull in the various orders to have 

 become familiar to me for the sake of comparison, expressed or 

 unexpressed. 



I have come to the conclusion that the Edentata 1 are nearer of kin 

 to the Monotremata than to the Marsupialia, and that if they did, 

 as indeed they must have done, pass through a Metatherian, or 

 Marsupial stage, they did not utilise it but ran through it in an 

 abbreviated pre-natal stage. 



Of course the remarkable modification of their jaws, due to 

 abortion, and in some cases complete suppression, of their teeth, 



* Professors Flower and Mivart, Drs. Giinther and Sclater, and H. M. Ward, 

 Esq., F.Z.S. 



