52 MR. E. T. BENNETT ON THE CHINCHILLIDZ. 
Lagotis, an inch and a half in length, with a breadth of an inch at its lower extremity. 
The latter part was broader in proportion in Chinchilla, the corresponding measurements 
being one inch, and seven eighths of an inch. The kidneys were of the usual form, the 
right considerably higher than the left ; the tubuli urinifert terminating, as in most Ro- 
dentia, in a single conical papilla: they measured, in Chinchilla, nearly three quarters 
of an inch in length by half an inch in breadth. The renal capsules were oblong white 
bodies, lying mesiad of the upper part of the kidneys, and measuring in Chinchilla 
nearly half an inch in length. In Lagotis, the omentum, which was of moderate size, 
as well as the mesentery, contained fat ; but this was wanting in Chinchilla, the indi- 
vidual having died most probably of a deficiency of nutriment, in consequence of an 
inability to masticate its food from the incisor teeth of the upper jaw having become 
excessively elongated and incurved, as happens not unfrequently in rabbits, rats, and 
other Rodentia. 
In Lagotis the urinary bladder was large, a good deal distended, and contained a 
firm, gritty, coagulated substance of a white colour, which Mr. Owen conjectured 
might possibly be formed by inspissated semen thrown back into it. The plewus pam- 
piniformis and spermatic omenta were well developed; and the vasa deferentia were 
large. The vesicule seminales formed tubes of three inches in length, giving off nu- 
merous ceca from one side. The testes were of the size of pigeon’s eggs, and the fibres 
derived from the transversalis muscle, adhering to the upper part of the epididymis, 
formed a sheath from which its extremity projected into the inguen. The prostate 
gland was large and lobed ; and the penis furnished with a bone. Both the Chinchillas, 
as well as that previously examined by Mr. Yarrell, were females: their organs pre- 
sented little that was remarkable. The cornua uteri measured three inches and a half 
in length. 
On opening the thorax of Lagotis, the heart was seen to be nearly quadrate in its 
form, with obscurely rounded angles; in Chinchilla it was more elongated and more 
rounded at the apex. The two superior vene cave were distinct. The lungs on the left 
side were divided into three lobes, of which the lowest was the largest ; and on the 
right into four, with the lowest also largest, and in Chinchilla deeply bifid. The section 
of the trachea was transversely oval, with the rings imperfect behind. The tongue, in 
both animals, was broad at the base, becoming narrower anterior to the molar teeth, 
from which point it was continued forwards nearly of the same breadth. It was rather 
flattened, and rounded at the extremity; its surface being finely papillose, except 
between the molar teeth, where it was smooth. Behind this part were two large oblong 
papille fossulate, disposed obliquely, with their posterior extremities directed inwards 
and towards the epiglottis. 
My friend Mr. Owen, to whom I was indebted for assistance in the dissection of 
Lagotis, and who has since examined another specimen of Chinchilla from the Society’s 
Collection, has favoured me with his notes, in which he gives a much greater length 
