1152 PROF. J. p. HILL AND MK. R. H. BUENE ON THE 



(Hubrecht, 8, p. 93), nor with that of the somewhat similai* 

 villi of Galago (Strahl, 14 & 15, ]3l. 38. fig. 17) ; it is simply a 

 slight elaboration, such as that described by Strahl in the later 

 stages of Propithecus, of the laminar arrangement typical of all 

 the Madagascar species. 



In opening the uterus of specimen A, it was observed that the 

 folds and corrugations upon the surface of the chorion fit closely 

 into the corresponding depressions in the uterine mucosa. The 

 connection between the two is, however, relatively slight, and by 

 gentle traction the chorionic sac can be detached from the viterus 

 without rupture of tissue. The degree of cohesion between the 

 two diifers in different parts, depending on the size and compli- 

 cation of the folds and the depth to which they interdigitate 

 with the corresponding irregularities of the uterine mucosa, 

 being greatest in the non-fostal (rigiit) horn, where the chorionic 

 folds are most pronounced (PI. 1. fig. 1) and least towards the 

 cervix, where they are fewer and less prominent. 



Although, as mentioned above, the folds cover most parts of 

 the chorion, there are areas from which they are almost or 

 entirely absent (PI. I. fig. 1). Such bare places are very ill- 

 defined, and although at first sight they suggest the bare patches 

 described by Milne Edwaids (3) and Turner (S), and figured by 

 Strahl for Propithecus (15, pi. 37. fig. 14), they can hardly bear 

 a strict comparison with them. In the first place, they are in 

 every way so much less definite arid in the second place, they 

 have apparently no uterine counterpart in the form of bare areas 

 of the mucosa. 



The position of these relatively bare areas is no more definite 

 than their boundaries ; some can be observed towards the base of 

 the left (foetal) horn and in the region of the corpus uteri, more 

 particularly towards the cervix where the chorionic folds become 

 smaller and less numerous than elsewhere and ultimately vanish, 

 leaving the conical process of the chorion that occupies the cervix 

 perfectly smooth. In this complete absence of folds at the pos- 

 terior extremity of the chorionic sac in specimen A, the placenta 

 conforms to the type " placenta en cloche," as originally described 

 in Propithecus by Milne Edwards (1). 



The chorionic sac of specimen B was figured by Hubrecht 

 (10, pi. GG, fig. 151). It had been opened dorsally from a point 

 opposite the lumbar region of the foetus to the head. In all 

 essential features it resembles that of specimen A. The laminar 

 folds are fairly evenly distributed upon the surface of the sac 

 opposite the right side of the foetus (PI. III. fig. 4) ; they are 

 closely crowded together, and are arranged for the most part trans- 

 versely to its long axis. Towards the hinder end they become (as 

 in specimen A) less continuous and less closely packed than further 

 forward, and show four areas apparently bare, but in reality 

 covered with fine ridges and grooves, giving an appearance of fine 

 striation (Pis. III., IV. figs. 4 & 10). Opposite the left side of the 

 foetus (Pis. III., IV. figs. 5 & 7) is the process or appendage, as 



