ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
185 
were seen which only wanted their generative apparatus to be young 
Distoma. The author was not able to trace the parasite beyond the 
body-cavity of its host. 
5. Incertae Sedis. 
Rotifers of Gulf of Bothnia.* — In addition to describing the rotifer- 
fauna of the Gulf of Bothnia, Dr. L. H. Plate makes some observations 
on the anatomy of the Philodinidae and the systematic position of the 
Rotifera. About a dozen species were observed, three of which — 
Synchseta monopus, S. apus, and Asplanchna syringoides — are new. 
The author’s views as to the systematic position of the Rotifera will 
be best understood from his own diagram. 
(Feripatubs ) 
Dr. Plate gives an account of his recent observations on the anatomy 
of Motifer vulgaris, which appears to be still incompletely known. The 
most important points on which exact information is required are the 
structure of the cloaca and contractile vesicle, the question of the mode 
of escape of the embryos, and the structural arrangements of the peri- 
pheral nervous system. The two lateral water-vessels open into the 
bladder, at its anterior and ventral margin, in a way which has not been 
observed as yet in any other Rotifer. The two canals unite to form 
a glandular body, which has the same structure as the enlargement 
formed by each water-vessel in the anterior end of the body ; a finely 
and closely granulated mass of protoplasm is traversed by a wall-less 
lumen which forms coils within it. It is possible that this common 
tract of the excretory canals in Botifer has been already seen by other 
observers, and regarded by them as being a vesicle in a state of systole. 
The cord which extends from the hinder end of the gonad is either 
connective or muscular tissue, but it is not a rudimentary oviduct ; it 
* Zeitschr. f. Wise. Zool., xlix. (1889) pp. 1-41 (1 pi.). 
