MAMMALIA — RODENTIA. 
49 
teeth have a furrow lengthways. Lund’s N. antricola is evidently 
nearly allied to Loncheres unicolor, Riipp., which I have characterized 
in these Archives last year (1 Bd. s. 361), without being perfectly sure 
of ranking it under Loncheres, since its teeth were not known to me. 
Two other Brazilian species, L, macrura and nigri-spina, Natt., are 
described at the same place. 
CuNicuLARiA. — Riippell has added one of the most 
remarkable forms to Mammalia in his new genus Hetero- 
CEPHALUS. 
It is represented in the Mus. Senckenb. iii. p. 99, tab. 8, fig. 1, and 
tab. 10, fig. 3. Skin almost wholly naked, with single hairs here and 
there ; body plump ; eyes small ; external muscles of the ear obsolete ; 
limbs strong, five toed, with stout claws ; tail rather short ; cutting 
teeth strong, smooth, obliquely sharpened; molars |, consisting of a 
simple cylinder, the upper ones with an indentation on the inside, the 
under with two indistinct protuberances pushing against each other. 
To the only hitherto known species, Riippell has given the name 
Heterooephalus glaber ; body, in a straight line, 4" ; tail V' ?>"' ; fore- 
foot, with middle claw, ; hind-foot, with middle claw, 10'" : lives in 
holes in the meadows of Schoa. The reporter, from the plate, finds the 
skull most nearly resembling that of the Oeorhychus. 
Ruppell has made another important addition to this family, in a 
second North African species of Rhizomys {Tachyoryctes). Lib. cit. 
p. 97, tab. 8, fig. 2 ; tab. 10, fig. 2. He calls this species Rhizomys 
macrocephalus ; hair pretty long and extremely delicate ; whole upper 
surface rich reddish-brown with a beautiful silky gloss verging towards 
metallic (hairs dark bluish-grey, with brown tips) ; under side dirty 
yellow grey ; body 12" ; tail 1" 9"' habitat, earth passages of the 
pasture meadows of Schoa. 
J. E. Gray has defined another species under the name of Rhizomys 
minor ; fur grey with browner ends, long, very silky ; whiskers brown ; 
sides of head rather browner; tail naked; body 6^" ; tail If" ; Indian 
or Cochin China? (Ann. x. p. 266.) 
Bachmann, in the Journ. of Philad. viii. 1, p. 103, has more exactly 
characterized Ascomys {Geomys) borealis. Rich., and A. Townsendii, 
Rich., hitherto only known by an unsatisfactory notice. A. borealis is 
pale grey ; superiorly washed with yellow ; under side, feet, claws, and 
tail white ; cutting teeth anteriorly yellow ; in the upper ones a slight 
groove, towards the inner margin, is visible by means of a magnifying 
glass ; body ; tail 2". Bachmann acknowledges, that he has not 
been able to find out the difference between this and the A. Townsendii, 
He states the body of this latter to be the tail 2f". Richardson 
93 
