extensively palmate, whilst in Borboroccetes the hinder legs are much longer, and
the toes scarcely at all webbed. The former structure indicates a greater power
of swimming, and the latter of leaping.
B o r b o r o c c e t e s B i b r o n i i . 3Iihi.
P late X V I I. F ig. 1.
Dentihus palatinis in fasciculis disiantibus obliquis pone nares posteriores positis;
palmis bituberculatis.
Habitat, Chiloe and Valdivia.
D e s c r ip t io n .—H e a d depressed, th e v e rte x slightly concave b etwe en th e o rb its ; fro n t (space in cluded
betwe en two lines d rawn from th e a n te rio r c o rn e r o f th e orbits to th e p o in t o f the
nose) tria n g u la r an d distin c t. N o strils la teral. E y e s ra th e r p rom in en t. T o n g u e broad,
ovate, a c um in a ted in fro n t, b e h in d en tire an d ro u n d ed , th e posterior h a lf an d th e sides d e tached.
P a la tin e te e th in two oval parcels, d ire c t obliquely backwards a n d inwards, an d
s itu a ted a t some distance b eh in d th e lin e o f th e p o sterio r m a rg in o f th e nares. T ym p an um
concealed. B o d y ra th e r depressed a n d sh o rt. S k in smooth a n d with o u t pores o r glands,
ex c ep tin g on th e posterior a n d in ferio r surface o f th e thighs, whe re th e re are some small
g ra n u la r elevations. F o re legs two-thirds th e le n g th o f th e h e a d an d body. T h e fore-arra
ra th e r la rg e r th a n th e u p p e r arm. T h e fingers en tire ly sepa rated, th e th ird considerably th e
longest. A small tuberc le u n d e r each jo in t, a n d two on th e p a lm n e a r th e wrist. L e n g th of
th e h in d e r legs to th a t o f th e head a n d bod y as 5 to 3, o r ra th e r more. T o e s co n n e cted only a t
th e ir base. A small tu b erc le u n d e r ea ch jo in t, an d a very depressed one a t th e base o f the
in n e r toe.
C olour o f th e u p p e r p a rts fuscous, with a late ra l fascia ex te n d in g from th e o rb it n ea rly to the
thigh, o f a d ark-brow n colour, b o rd e red w ith w h itish ; a n d an o th e r o f an elonga ted trian g u lar
form on ea ch ilium. Legs w ith transverse incomplete facias o f th e same colour. U n d e r
p arts g rey , w ith numerous brown dots.
DIMENSIONS.
I d. Lines.
Length of the body and h e a d ................................... 1 5
of the anterior extremities .......................... 1 0
of the posterior extremities ..................... 2 6
Taken a t Valdivia and a t Chiloe, in a thick forest, by Mr. Darwin.