Mr. O. Thomas on the Echimyine. 297 
It thus appears that the ranges of the genera of the present 
group are to a great extent separate, Nelomys being South 
Brazilian, Echimys and Isothria occurring in ‘Amazonia and 
the Pipaicies to the northwards, while “Diplomys is alone 
foundain Colombia and Panama. 
With regard to the species of Velomys, much confusion and 
ignorance exists, largely owing to the fact that so many of 
the earlier species were described without their exact localities 
being known, and often without reference to their dental 
characters. For these reasons it is impossible to identify 
with any certainty, and I would propose altogether to set 
aside, the animals bearing the specific names of didelphordes, 
ecm. obscurus, Wagu., and unicolor, Riipp., until such 
time as a competent examination of the type-specimens shows 
what the names represent. Possibly, however, all three are 
_the form of the Rio Janeiro region, for which I now pro- 
visionally use Lund’s name brasz/iensis. 
Wagner’s nigrispina, of Sio Paulo, is as yet unrepresented 
in the Museum ; but, thanks to the kindness of Dr. H. von 
Ihering, we have three specimens of the largest species, 
thomasi, of the Island of Sao Sebastiao, originally described 
asa Mesomys. And of the smaller southern forms, medius 
and dasythriz we have a number of specimens, including the 
type of the former and a co- typical siull from Hensel’s 
collection of the latter. 
From the most northern point of the range of the genus, 
north-west of Bahia, we have a fine series of a species which 
appears to be new, and may be called 
Nelomys lamarum, sp. n. 
Size small, about as in brasiliensis and dasythrix. General 
colour paler than in any other species, the general tone above 
little darker than ‘‘ ochraceous buff”’ ; sides clearer and paler, 
becoming more drabby on the sides of the belly. Underside 
generally pure white to the roots of the hairs from chin to 
inguinal region, but the white is of very variable breadth, 
either extending uearly the full breadth of the belly, nar- 
rowed to a mere middle line, which is the most usual condition, 
or altogether interrupted over the ventral area. Head rather 
greyer than back ; whiskers and the inconspicuous tufts over 
the ears brown. Spines of back about 18 mm. in length, 
grey, with a blackish subterminal band and a buffy tip; hairs 
between the spines similarly grey, with bright buffy or 
ochraceous ends. Hands and feet buffy whitish. ‘Tail about 
as long as the trunk, its base hairy, the remainder thinly 
hairy, the hairs not hiding the scales, the terminal tuft little 
