194 Transactions of the Royal Society of South Africa. 
described it under the name Planaria subclavata. Rudolphi (22) placed it 
in his own genus Amphistovna. Diesing (9) established the genus Diplo- 
discus, and referred Amphistoma subclavata to Diplodiscus, calling it Diplo- 
discus subclavatus. Later authors — Filippi, 1855 ; La Valette de St. 
George, 1855 ; and Pagenstecker, 1857 — devoted themselves to observa- 
tions on its anatomy and life-history. Von Linstow described the repro- 
ductive system fully, and observed the independent movements of the 
vitellogenous granules. It was Looss (16), however, who, in 1892, published 
a complete account of this well-known parasite and fully established its 
life-history. 
Judging from the size of the suckers, length of intestinal limbs and shape 
of the testes, I found the South African specimens from the rectum of 
Xenopus laevis (Stellenbosch, Paarl, and Kuilsrivier) identical with the 
European representatives. The Australian representatives constitute the 
species D. megalochrus Johnston and D. microchrus Johnston (14). 
I wish here to record the discovery of two other trematodes found in 
Xenopus laevis, which I have thus far been unable to refer to their natural 
position among the Malacotylea. The following is a preliminary account. 
Preliminary Account of a Distomid found in the Gall-bladder 
of Xenopus laevis. 
The presence of these worms in the gall-bladder of Xenopus laevis 
imparts a pronounced yellowish-green colour to that organ. On opening up 
the gall-bladder the worms were found shrouded in a dense mass of a partly 
coagulated substance. They occur singly or in pairs, more often in pairs. 
The body, about 7 mm. long, is divided into two distinct regions of more or 
less equal length : an anterior narrow region -5 mm. wide, and a posterior, 
flattened, oval region about 2 mm. wide. Posteriorly it ends in a moderately 
smooth curve. The anterior half is mobile, carrying the anterior and posterior 
suckers, of which the former has a diameter of -17 mm. and the latter of -1 mm. 
It has a well-developed bulbous pharynx, short oesophagus, and intestinal 
limbs which do not extend to the posterior extremity. The testes are 
rounded, and placed symmetrically at the same level on each side of the 
body just within the intestinal limbs in the posterior region of the body. 
The compact rounded ovary is almost symmetrically placed in front of the 
testes, slightly to the left of the middle line. The coils of the uterus, filled 
with yellowish-brown eggs, are confined to the region between and behind 
the testes, and do not extend over the intestinal limbs on each side. The 
vitellaria are lateral, extending from the level of the posterior sucker to a 
point a short distance in front of the termination of the intestinal limbs. 
They form dendritic clusters arranged on each side external to the intestinal 
