438 Miscellaneous. 



the gonys ; the margins of both mandibles are dentated in the 

 middle. 



The length from the upper part of the base of the casque to the 

 tip of the maxilla is five inches and three lines. 



The head which forms the subject of this description is supposed 

 to have been brought from West Africa. 



Observations on some points in the Emhrriology of the Lemuroidea, 

 and on the Zoological Affinities of those Animals. By M. Alph. 

 Milne-Edwards. 



In all existing systems of classification the Lemuroidea form ■\\4th 

 the Monkeys a single group, called the order Quadrumana. Various 

 anatomical considerations had led me to doubt the correctness of 

 this approximation ; and I had a lively desire to ascertain whether 

 the characters drawn from the development of the embryo would 

 support or contradict it. Therefore, when my friend M. A. Grandi- 

 dier started upon his last voyage of exploration in Madagascar, I 

 directed his attention to this point, requesting him to seek carefully 

 for female Lemuroidea in a state of gestation. The results obtained 

 by him surpassed my hopes ; for he procured foetuses belonging to 

 four different genera of the group Lemuroidea ; and these he has 

 been kind enough to place at my disposal. 



The dissections that I have made of these have enabled me to 

 ascertain that, with regard to the intra-uterine development, there 

 exist essential differences between the Lemuroidea and the Apes. 

 It is well known that in the latter the placenta is small, discoidal, 

 and intimately united with the uterine decidua, and that the um- 

 bilical vesicle is greatly reduced, and even disappears very early. 

 The Lemuroidea present a very different arrangement. Thus, in 

 Projnthecus, which maj^ be regarded as one of the highest repre- 

 sentatives of the type under consideration, and consequently as 

 nearest to the Monkeys, the chorion is almost entirely covered with 

 thick and close villosities, constituting a sort of vascular cushion, 

 and forming the placenta, which forms almost a complete hood over 

 the amnios, and which I shall denominate the bell placenta {pla- 

 centa en cloche) in opposition to the discoidal placenta of man and the 

 monkeys, the zonary placenta of the Carnivora, and the diffused 

 placenta of the Herbivora. The viUosities, which are very much 

 tufted towards the middle and upper portions of the ovum, gradually 

 diminish as they approach the cephalic pole, where they disappear 

 almost entirely over a small space. The uterine decidua is greatly 

 developed, and presents a corresponding arrangement. 



Between the chorion and the amniotic coat we find a vast mem- 

 branous sac extending in the direction of the major axis of the 

 ovum, and adhering to the umbilical cord by a short slender peduncle. 

 This sac is elongated so as to form at each of its extremities a sort 

 of digitiform horn, and only contracts slight adhesions to the two 

 Hdjacent coats ; none of the large vessels of the cord are distributed 

 upon it. If air is injected into this sac under water, it is distended 



