102 EINAR LÖNNBERG, MAMMALS COLLECTED BY THE SWEDISH ZOOLOGICAL EXPEDITION ETC. 
A series of eleven specimens from this locality display a rather great variation 
with regard to colour as well. The young are, of course, black, but the adult have 
sometimes hardly any black at all on the head, and sometimes an old specimen with 
well developed crests on the skull has the entire head black. There is also a nearly 
albinistic specimen in the collection. This one is whitish ash-coloured with pale 
buffish tips to some of the hairs. 
Around Meru boma these Mole-rats were very common in the shambas. 
Bathyergide. 
Heterocephalus glaber progrediens n. sp. 
This peculiar Naked Rat was observed in the thornbush country north of Guaso 
Nyiri, and four specimens were captured. When one sees this quaint and naked being 
the first impression is that it is the newborn young of some large rodent. The 
nakedness, blindness, comparatively small feet but big head make it look like a foetus. 
But the ferociousness with which it at once bites anybody or anything that touches 
it, soon takes away the belief in its youth and harmlessness. It lives entirely under 
the ground, and its burrows appear to be long but mostly situated rather near the 
surface. Here and there the burrow has openings through which the earth is thrown 
out rapidly in thin squirts. The result of this is small hills which DRAKE-BROCKMAN 
very properly with regard to their appearance compares with »miniature volcanoes».' 
Often quite a number of such little hills are situated near each other in rows along 
the burrows. It appears most probable that the animals do most of the digging 
with their powerful incisors as the feet look very weak. The throwing out of the 
earth is of course effected with the hind feet, which are especially adapted for that. 
The outer appearance of these peculiar animals has been repeatedly described by 
FUPPEL,” ÖLDFIELD THOMAS,” PARONA & CATTANEO'" etc. 
One of my specimens is figured Pl. III, fig. 2, and the head of the same, a 
little enlarged, is seen on the same plate fig. 3 from its anterior end. "These two 
figures show the arrangement of the hair and bristles on the head and body, while 
the peculiar fringes on the feet are elucidated by fig. 4 which shows a hind foot 
seen from above, twice enlarged. 
In the interior of the mouth as well some scattered bristle-like hairs are found 
on the insides of the cheeks in front of the molars as may be seen on Pl. III, fig. 5. 
In this figure as well the structure of the palate is shown. It differs from that of 
Fornarina plullipsi THOMAS in having only two pair of palate-ridges, the anterior 
pair of which is confluent, while Fornarina to judge from the figure communicated 
by THOMAS: (1. e. Pl: LIV: fig. 2) has four. 
1 The Mammals of Somaliland, London 1910, p. 137. 
> Mus. Senckenb. Abh., Bd. III, Frankfurt 1845, p. 99—101. 
2 Proc. Zool. Soc... London 1885, p. 8405-849; 
! Ann. Mus. Civ. Genoa, Ser. 2, Vol. XI, p. 419—445: 
