PLANARIANS FROM MAURITIUS AND RODRIGUES 147 
vestibulum is supplied with an annular outbulging, which 
extends more deeply backwards than forwards. To me, this 
outbulging appears to serve as a seminal receptacle during 
copulation. 
Amblyplana trifuscolineata, n. sp. 
(PL. 4, figs. 4, 5.—Text-figs. 5, 6.) 
This new species is represented by a single specimen which 
was taken by Mr. Thomasset under a half-rotten log in the 
island of Mauritius. 
Kxternal Characters (Pl. 4, figs. 4, 5)—The body, 
which is nearly circular in cross-section, is rounded at the 
posterior end, and has the lateral margins even and nearly 
parallel for a large part of its length, but tapering in front to 
the bluntly poimted extremity. The sole corresponds nearly to 
one-third the width of the body, extending to both extremities. 
It measures 25 mm. long by about 3 mm. across in the broadest 
part. 
In coloration this species nearly resembles Geba’s Am bly - 
plana tristriata, described by that author from the 
Comoro Island. The dorsal surface is of a dark colour with a 
touch of olive-hke brown, and marked with three longitudinal 
black stripes, a median and a pair of laterals, the latter con- 
verging towards the extremities of the body, without coalescing. 
Ventrally, the colour is similar to that of the dorsal side, except 
for the creeping surface which is pale, while each side of it has 
a diffused brownish black tinge. 
Near the anterior tip of the body le the eyes, one on each 
side, as shown in T'ext-fig. 5. 
The mouth-opening, which leads into the peripharyngeal 
chamber, is situated at a short distance behind the centre of the 
body. I could.make out its position by a slight protrusion of 
the pharynx. 
The common genital opening lies at the hind end of the first 
third of the distance from the mouth-opening to the posterior 
extremity of the body. 
L2 
