246 58 



long neck, which is worked up and down the foot, and is capable of protrusion from its 

 extremity. Size male S4 u. Time 2nd April. 



Kr.\tzschmar (1908, p. 630. Tab. XIV, lig. 1 — 2) has given a verj- thorough 

 description of the male and three interesting figures. His paper is of great interest, 

 because his observations are based upon cuts; as far as I know, it is the first time 

 a Rotifer male has been treated under microtome. 



The main points in the description are as follows: 



Body conical; a dorsal lorica with a median cleft; ventral side without lorica; wheel- 

 organ can be withdrawn Ln the lorica by means of strong muscles. It presents no peculiarities. 

 Xo alimentary canal; a large brain with a crimson eye; no antennae obser\-ed; a large testis 

 with spermatids and spermatozoa; penis large, in cross section oval; the ductus seminalis 

 covered with cilia; two ventrally and two dorsally situated muscles. Over the testis a large 

 oil globule. Krâtzsch.\lvr supposes that the function of this oil globule is to prevent the 

 rotating motion in such a way that the swimming course becomes straight, the way being 

 shortened in this manner, and the speed of the male sex being augmented. The pheno- 

 menon is due to the fact that the buoyancy of the oil globule is greater than the force which 

 is used during the rotating motion. It is further of the greatest interest, that Krâtschm.a^r 

 has been able to show by means of cuts, that this organ is in connection with the excre- 

 tory organ. The oil globule is surrounded by a light-refracting sphere, which is further 

 surrounded by an opaque mass of dark grains; the two lateral canals unite below the 

 brain and dilate into a large sack, enveloping the oil globule and the surrounding cell 

 masses; from the underside of the sack runs a canal which opens dorsaUy upon the animal 

 in the median line; the opening is surrounded by a ring; the lumen of the canal is always 

 conspicuous, and the walls are stiff; it is supposed, that there is always a connection between 

 sack and outer medium. It is of special interest that Krâtschm.\r has shown that the muscles 

 are transversally striped. One pair of transversal muscles are obsened. Size: Length of body 

 70". Breadth 35/(. Penis 20 /t. 



MoNTET (1915, p. 342, PI. 13, fig. 39) figures the male, but gives no description at all; the 

 figure is very difficult to understand. 



Male: Description: Body broad, conical, tailless, broadest in the middle, and 

 with a peculiar notch dorsally. A relatively thick cuticula, but no conspicuous lorica; 

 this is most developed on the dorsal side. Ventrally is found a quadrangular plate 

 from the edges of which lines run out to the sides of the body. In some individuals 

 I think, I have seen a lorica, somewhat resembling that of Salpina with a median 

 cleft ranning from a little below the wheel-organ downwards to the penis. But this 

 line is not conspicuous in all individuals. The wheel-organ consists in a single ciliary 

 wreath, slanting a little ventrally, encircling a disc with three bunches of longer 

 cilia and four strong setæ. Xo alimentary canal; a very large, remarkably broad 

 brain with a broad red eye spot. I have not been able to see any dorsal antenna. 

 Two conspicuous lateral antennæ are situated in the posterior part of the bodj'. 

 Of the excretory organ I have only been able to see a short part, h'ing between 

 brain and testis; it is provided with two vibralile tags; no contractile vesicle. Testis 

 large, globular, with two sorts of spermatozoa. Penis well-developed, strong, rather 

 thick, with two small muscles; ductus seminalis covered with cilia and round the 

 opening a tuft of cilia; in the posterior corners of the penis two strong hairs. Well- 



