57 245 



canal now used as ligamentuni for the testis are most probably almost always pre- 

 sent. The brain carries a red eye; dorsal and lateral antennæ are in all likelyhood 

 always present. In the excretory organ the contractile vesicle is absent; three or lour 

 vibratile tags; a large testis with prostata glands. Very peculiar is the structure of 

 the penis; with regard to this point I refer to B. pala. Above the testis a conglomerate 

 of opaque, sharp edged grains. It is of interest, that a series of transvei-sal muscle 

 bands can often be pointed out. 



The males are all extremely quick and are hatched in great numbers in tlie 

 sexual periods. Often I have had small clouds in the vessels, consisting almost 

 entirely of newly hatched males. 



Anuræadæ. 



The family Anuræadæ consists of the three genera Aniiræa, Aniirœopsis and 

 Notholca. Apart from A. aculeata there exists no drawing or description of anj' male, 

 belonging to this family; the male of the most common Rotifer, that of A. cochlearis 

 has hitherto been unknown. Rousselet (1903, p. 176) states that the male of N. 

 heptodon has been observed, but gives neither description nor figure. 



Anuræa aculeata Ehrbg. 



Male: Plate 1886, p. 64. 



Marks & Wasche 1903, p. 5U9. 



Krätzsehniar 1908, p. 630. 



Montet 1915, p. 342. 



Tab. XIII, fig. 1—2. 



Plate (1886, p. 65) with regard to the male says only as follows: 



"Sie haben cylindrische Gestalt: vorn sitzt der Räderorgan, unter dessen Wimpern sich 

 einige durcli besondere Länge auszeichnen, hinten verjüngt sicli der Körper zum Penis und 

 endet mit flimmernder, breiter Spitze. Von den übrigen Organen habe ich leider nur den 

 grossen Hoden und das Gehirn erkennen können, das ein dorsales Tastgriüjchen versorgt und 

 einen Augenfleck trägt. — Grösse 100 /(." 



A. aculeata var. brevispina. Marks & Wesché (1903, p. 509, PI. 26, fig. 2). 



The shape of tliis minute rotifer is inclined to be truncate, but globular, not so broad 

 as it is long, and the bodj', unlike that of tlie female, in a foot, ends usually pendant. — 

 Head stout, with a chitinous covering on the dorsal side, well marked in lateral view; this 

 folds up and encloses the head when the animal retracts the cilia. There is a deep constric- 

 tion at the neck. Body, enclosed in a carapace which has openings on the dorsum and sides, 

 so that it appears to be enclosed in three more or less arched plates; in the specimens seen 

 there was a conspicuous oil globule. The foot has a chitinous slieath, down which the passage 

 from the sperm-sack passes, so tliat it may be said to take the jdace of the penis. M the 

 extremely are two hyaline threads, as in Triarthra. Toes, none. Cilia fairly long. Brain, large 

 occupying all the head and part of the body. Eye large, bright red, circular in dorsal view, 

 narrow in lateral view, nearer the ventral than the dorsal side. Antennæ very minute on 

 head and sides of carapace. No digestive system. No foot glands seen but the animal seems 

 to spin a thread from foot. Vascular system very indistinct. No contractile vesicle. Generative 

 system a large pouch containing spermatozoa and other bodies; the pouch narrows to a 



D. K. Ü. ViUensk. Selsk. Skr., nalurv, og malhem. Afd.. 8. Bække. IV. 3. 33 



