1883.j The Extinct Rodentia of North America. 375 
distal extremity of a femur with a patella. These were the 
first evidences of the existence of 
the large rodent Amélyrhiza inun- 
data, which was described in the 
Proceedings of the American 
Philosophical Society for 1868. 
Other bones were found in other 
breccia masses, which I could not 
clearly refer to any other animal. 
With them occurred a shell of Tur- 
bo pica. 
Having learned that Dr. E. van 
Rigjersma, colonial physician of 
the Danish island of Saint Martins, 
was interested in the natural sci- 
ences, I wrote, asking him to make 
an examination of the deposit in 
question, and to secure, if possible, 
all fossils discovered in excavating 
it. He accordingly very kindly went 
to Anguilla and ,was rewarded by 
the possession of numerous addi- 
tional teeth and bones of Ambly- 
rhiza. Subsequent visits added 
two species of this genus, together 
with the bones of a species of g T 
A verda uncertain genus ; bones ; Fic. a = dg: o 
à probable rodent of smaller size '0™ Anguna, imo- 
of two species of birds, of a lizard are Psa ga mS A 
and a shell chisel of human man- ep ee tye i a 
ture, 
rom above. 
* . ` mandible of A. datidens Cope, show- 
pe Maree Species are A. inun- ing molar and lateral coronoid pro- 
data: A. quadrans and A. latidens °° 
Cope. The first named is the smallest species, and the teeth 
= Charleston are perhaps referable to it. All the species 
agree in Presenting the following characters : 
an Premaxillary bones and the symphysis mandibuli are 
much produced and narrowed, and were probably enclosed 
™ fur-bearing integument, as in the existing Chinchillas. The 
: - 
an Loxomylus longidens was probably based on inferior molars of this or of a 
y allied species, 
