220 On Four new South-American Mammals. 
Skull low and flattened. Nasals much expanded behind. 
Posterior lower premolar slightly smaller than the middle 
one. 
Dimensions of the type, in skin :-— 
Head and body 100 millim. ; tail 53; hind foot (moist- 
ened) 15; ear (above head) (c c.) 3. 
Skull: ‘basal length (c.) 25; nasals 12°5x 4:5 ; interorbital 
breadth 6; breadth of brain-case 11; palate length 15; com- 
bined length of m** 5:1. Lower jaw, condyle to tip of 
incisors 20°5 ; front of canine to back of m, 12. 
Hab. W. Cundinamarca, in the low-lying hot regions. 
Ly pes eM. Oat aes 
This species has most resemblance in colour to P. domes- 
ticus, Wagn., but differs by its much smaller size and 
smaller ears. From the known species of its own size it is 
readily distinguishable by its uniform brownish coloration. 
Ichthyomys trichotis, sp. n. 
Size smaller than in the other species. Colour dark 
smoky or slaty grey all over above and below, with the ex- 
ception of the chest and centre line of the belly, which are 
white. Ears short and narrow, their conch only standing 
up about 4 millim. above the crown, thickly clothed with hairs 
similar in colour and texture to those on the head, and of an 
equal length to that of the conch itself; as a result the ears 
are quite lost among the general fur of the head. Upper 
surface of hands silvery white, of feet rather more brownish ; 
hind toes apparently rather less broadly webbed than in the 
other species, and the pads smaller and more. distinctly 
defined. ‘Tail about as long as the body without the head, 
well haired, blackish throughout except at the extreme tip, 
which, as in L. hydrobates and Séderstrémi, is white. 
Skull unfortunately too much broken in the only speci- 
men to be described, and it can only be noted that the 
incisors, both above and below, are much thinner and 
narrower transversely and antero-posteriorly, and that the 
molars are of about the same size and proportions as those 
of I, hydrobates, or m® may be a little smaller. 
Dimensions of the type, in skin :— 
Head and body 130 millim.; tail 114; hind foot 28°5; 
ear, above head, 4. 
Skull: length of upper molar series 4°8, of lower molar 
series 4°9. Lower jaw, bone only, 13°5; to incisor tip 16°3. 
Hab. W. Cundinamarca, in low country near to Magda- 
lena R. 
Type. B.M. 97.7.2.2. 
‘This species resembles J, hydrobates, and, if really different, 
