288 100 



a long process to the dorsal antennæ. Eyes, two, red and well marked. Antennæ, all three in 

 the centre of the body, almost in a line. Setæ very fine and difficult to make out. Digestive 

 system, represented by a hyaline membrane, appearing to be in an atrophied condition. Vas- 

 cular system, faint; no contractile vesicle seen. Generative system, very large; spermatozoa 

 masses in testis; orifice of penis slightly ciliated and situated down the dorsal side of the 

 foot; no granular masses as in Brachionus. Size male 127— 135 /<. Time May 12th." 



RoussELET (1908, p. 27) says that, 



according to a letter to him, Bilfinger has observed the male, which agrees with that of 

 P. elliptica in every particular. 



It seems that also Dieffenbach (1912, p. 196) 

 has seen it and confirms the above named observation. 



Though I have seen very large maxima of P. patina especially in the winter 

 season I have failed to get the male. 



Pompholyx sulcata Hudson. 

 Tab. XIV, fig. 1. 



Description. Body globular, without tlie four longitudinal fun•o^vs, charac- 

 teristic of the female; the skin very soft, no regular lorica; a dorsal surface slightly 

 separated from the ventral one by means of a rather indistinct line, ending round 

 the opening for the testis. Near the forepart of the body a transversal line; before 

 it the chitine folded longitudinally, so that the body, seen from the front, when the 

 wheel-organ is drawn in, is crater-shaped. The wheel-organ consists only of a single 

 row of rather short cilia; as far as I have been able to see, the disc is not bare as 

 in the female, but covered with cilia. The band of cilia encircles the disc without 

 any interruption ventrally in the middle line. 



Below the ciliarj' wreath a series of indistinct hypodermal cells; a large brain, 

 carrying two red eyespots, each with a lens, situated in a spot, corresponding to 

 that of the female. I have not been able to see either dorsal or lateral antennæ; as 

 far as I know, they have never been observed in the female either. There is not 

 the slightest trace of an alimentär}' canal ; nor have I seen any part of the excretory 

 organ. There are two pairs of rather conspicuous muscles, running from the forepart 

 of the wheel-organ, one pair fastened near the middle of the body, the other nearer 

 to the hindpart. The whole animal seems to consist almost entirely of an extremely 

 large pyriform testis, iilling more than two thirds of the body cavity. Scattered over 

 and round the testis are large oil globules, different in number and size; the testis 

 itself contains rather few spermatozoa; I have hitherto not seen any of the staff-formed 

 ones. No prostata glands are found, and I have seen no penis. When strongly con- 

 tracted the body tapers behind, into two small tubercles, limiting the opening for 

 the testis; this opening is rather large and encircled by a row of short cilia. Size 

 of male 40/*, of female 90 /<-. Time 25/VIII 21. I have never seen the copula, but 

 very often observed the male rotating round the female. The males were hatched in 

 great numbers from the male eggs, carried by the females in my vessel. 



