440 On iioo neio Central- African Mammalia. 



ever, not so strongly made as in the latter, and if its cells 

 furnish nutritive material to the sperm-cells, their importance 

 is probably only that of an intermediate station. After the 

 last division the coil form of the nucleus passes into a per- 

 fectly dense chromatin-globule. This becomes the head of 

 the spermatozoon, and the scanty clear protoplasm which 

 surrounds it is drawn out into the filament. Sometimes 

 within the same follicle the development of the spermatozoa 

 goes on at different rates, so that, for example, one half of 

 it appears filled with mature spermatozoa, the tails of which 

 are all directed towards the centre, while the other half still 

 shows different stages of division. 



The development of the ova, as of the spermatozoa of 

 Spongilltty consequently approaches in a most satisfactory 

 manner to the processes repeatedly observed in higher animals, 

 although many peculiarities cannot be denied. 



LXV. — Diagnoses of two new Central" African Mammalia. 

 By Oldfield Thomas. 



The two following new species occur in the collection recently 

 sent to the Natural-History Museum by Emin Pasha. 



Dendrohyrax Emtm\ sp. n« 



Allied to and of about the size of B. arhoreus, Sm.^ 

 but, instead of greyish brown, uniformly pale yellowish white 

 all over above and below, very much the colour of the centre 

 of the belly of D. arboreus. 



Hah. Tingasi, Monbuttu, Central Africa. 



Anomalurus pusillus^ sp. n. 



Allied to and coloured above like A. Beecrofti^ Fraser, but 

 differing markedly by its much smaller size (hind foot 42 

 millim., molar series 9'5 millim. long) and by its greyish-white 

 instead of rufous underside. 



Bah. Bellima and Tingasi, Monbuttu. 



