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CONTRIBUTIONS TO A KNOWLEDGE OF SOUTH 
AFRICAN HIRUDINEA. 
ON SOME POINTS IN THE ANATOMY OF MARSUPI- 
OBDELLA AFBICANA. 
By Professor E. J. Goddard, B.A., D.Sc, and D. E. Malan, M.A. 
(Keceived October 15, 1912.) 
(Eead October 16, 1912.) 
Pis. XV.-XVII. 
IvIarsupiobdella africana. 
Eecently we described" the externals of this form, and laid down the 
diagnostic characters of the new genus. 
We propose in this brief paper to deal with the more interesting of the 
internal structures which have been specially modified by the development 
of the brood pouch, which is so enormously developed and unique as an 
internal structure in the Hirudinea. 
The chief modifications concern the digestive, reproductive, nervous, 
and muscle systems, and these are the result of displacement. 
Preliminarily, we take this opportunity of rectifying an omission. In 
the previous description we omitted to mention the presence of a pair of 
eyes on the second annulus. 
Body Wall and Brood Pouch. — The brood pouch occupies the greater 
portion of the body extending in a median longitudinal section through 
somites xv-xix inclusive. Transverse sections show clearly that both 
anteriorly and posteriorly horns are given off, and the importance of these 
varies according to the contents of the pouch, and these continue the 
pouch forwards into xiv and backwards into xx. Within the pouch we 
have found young in various stages of development from the segmenting 
egg to the fully developed young. The extensions and relations of the 
pouch to other body structures are clearly shown in the figures. 
The body wall has the typical Glossiphonid appearance, and the saixie 
applies in regard to the general body structure and sinuses. The great 
* "Annals of South African Museum," vol. xi., 1912, p. 309. 
