~“ 
296 Mr. O. Thomas on the Echimyine. 
de Deos, Bahia, by M. Blanchet, and sent by M. Pictet to the 
Zoological Society’s Museumin 1838 (B.M.no. 55. 12. 24. 116). 
Unfortunately the skull is missing, one ramus of the lower 
jaw being alone preserved; but from this, as from the figures 
of the teeth published by Geoffroy and Wagner, there can be 
no doubt that this handsome species, of which no recent 
specimens have been recorded, has the laminated upper teeth 
above described. Whence it follows that the genus should 
be termed Nelomys, this name antedating Phyllomys by two 
years. All the species of the genus are spiny, for it now 
proves that the non-spiny species deserve generic separation 
from true Velomys. 
“« Loncheres’’ caniceps, Giinth., from Antioquia, is the first 
described of these latter, and, besides the type, the Museum 
contains an example from Bayone, North Keuador, collected 
by Flemming and Miketta. Two other allied species, both 
from Panama, are Loncheres labilis, Bangs, and Isothrix 
darling?, Goldman. All three have been placed in Phyllomys 
by Goldman. 
But on examination of the teeth of the two specimens of 
caniceps above referred to, I have found that not only are the 
upper molars transversely laminated, as in Nelomys, but the 
lower molars are of similar structure, which is not the case 
in Nelomys, whose,lower teeth, unlike the upper, are compli- 
cated, very much as in Hehimys, with the laminz variously 
forked and united. Excellent figures of two stages of the 
Nelomys molars were given by Hensel *, and from these the 
characters may be readily perceived. 
But in caniceps, and presumably in labil’s and darling?, all 
the lamine of the lower teeth are as completely separated as 
those of the upper teeth, and though the middle one of each 
molar is slightly bowed and angularly convex forward in the 
centre, yet there is no complexity or junction between different 
laminee, as is the case in Nelomys. 
On this account I have suggested t that a new genus, 
termed Diplomys, should be formed for caniceps and its 
relatives. Briefly stated, its diagnosis would be as follows :— 
Lower molars simply and transversely laminated, duplicating 
the character of the upper ones. 
Fur rather harsh, but not definitely spinous. Other 
characters as in Nelomys. 
Genotype. Diplomys caniceps (Loncheres caniceps, Giinth.). 
Other species. 1). labilis (Bangs), D. darling? (Goldman), 
Range. Panama, Colombia, and Ecuador. 
* Abh. Ak. Berl. 1872, pl. i. figs. 11 & 12. 
t Ann. & Mag. Nat. Hist. (8) xviii. p. 240. 
