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A MESOSTOMA FEOM BLOEMFONTEIN 
(M. KABBOOENSE, n. sp.). 
By T. F. Dkeyer, B.A., Ph.D. 
(Bead September 16, 1914.) 
About a dozen specimens were collected in a small temporary pond on 
clay soil on the hill behind the Grey University College. The pond is 
always contaminated with cattle droppings. 
As long as the pond contains water it is regularly visited every week, 
but although this has been done for the last two years, the worms have 
only been found once — in May, 1914. They were all more or less con- 
gregated together in one part of the pond, and were all actively producing 
spermatozoa ; a few" had no eggs in the uteri, but most had from one to 
four reddish-brown "winter-eggs " in each uterus. 
The worms measured (preserved in HgClj) : Length up to 10 mm. ; 
breadth 4-5 mm. A typical specimen was 9-5 long by 4 broad, with the 
genital aperture 4*5 from the anterior end (6, Fig. 1) and 5 from the 
posterior end ; with the mouth (5) 2 mm. anterior to the genital aperture. 
The outline of the preserved specimen is shown in Fig. 1 ; the anterior 
end is squarish on account of the sucker (4 in A — A, Fig. 1) being 
retracted. On the dorsal surface in the anterior region there are two 
sharply defined ridges (1, Fig. 1). Laterally the body is expanded into 
two flaps which tend to curl upwards, especially in the posterior region. 
The pharynx is of the type called rosulatus ; the excretory system 
resembles closely that of M. elireiihergii, except that the "oral" cup is 
not well defined ; there are two eyes with black pigment which, in sec- 
tions, is seen to be prolonged into the mesenchym as fine strands ; the 
colour is dirty yellowish white with the region of the gut dirty brown 
owing to the secretions of the vitellaria and of the endoderm cells ; the 
ectoderm is densely packed with rhabdites ; the cerebral ganglion is pro- 
duced backwards into a pair of ventral and a pair of lateral nerve chords ; 
there is no otocyst. 
The reproductive system, which is of prime importance for the classi- 
fication, is described in greater detail. 
