37 225 



pulatory organ consists of a chitinous sheath which may he regarded as a con- 

 tinuation of the envelopment of the testis. The sheath consists of two hyaline chili- 

 nous bands, separated from each other; between them is the real penis, which is 

 a little shorter than the sheath. The penis can be protruded and then the whole body 

 will be curved often in such a high degree, that it is almost ball-shaped. There are 

 two prostata glands. Above the testis is a globular mass, containing many opatjue corns 

 of irregular, often quadrangular, form. At all events there are three or four trans- 

 versal muscle bands, most probably more, and four strong pairs of longitudinal 

 muscles. Oil globules wanting. Two foot glands. Size of male 300 /* of female 300 



— 350;ll. 



The species was common in a little pond near Hellebæk, North Seeland (Time 

 "/v 22) ; it was easily recognisable from almost all other Diglenas only by means of 

 its size. The pond was covered by a peculiar carpet of waterplants mainly formed by 

 Myriophyllum and Lemna pohjrrhiza. When squeezing this material in a plancton 

 net, very many different Rotifers appeared. Among them one of the most characteristic 

 was this large, extremely voracious animal, which preyed upon all that came near 

 it. Isolated in the vessels manj^ eggs were laid upon algæthreads and a few males 

 appeared in the light-illuminated border of the vessel. 



Diglena catellina Ehrbg. 



Male : Weber. 1888 p. 46. 



1898 p. 494. PI. XIX fig. 13. 

 Tab. I, fig. 8. 



Weber (1888 p. 46; PI. XXXIV fig. 1, 4, 5) describes the male as follows. 



Body cylindrical, ditTering in form from that of the female, a little smaller, more stretch- 

 ed, narrower and slightly curved on the dorsum. Cuticula very thin and hyaline. The wheel- 

 organ exactly in accordance with that of the female; a feeble groove where the mouth is to 

 be found in the female. A well-developed muscular system which has not been more thoroughly 

 studied. The digestive sj'stem totallj' absent; in its place a long series of granulations. Vas- 

 culary sj'stem consisting in two canals, beginning near the brain and opening on each side 

 of the penis; the opening round, encircled by cilia; only three vihratile tags seen; in the female 

 four. No contractile vesicle; an olive-formed brain with a dorsal antenna. Two eyes on the 

 forepart of the head. The foot with long; slender, acute toes. Testis piriform, very large, 

 suspended by means of fine ligaments from the body wall and by means of a muscle to the wheel- 

 organ. Near the base a longitudinal .striation, probably deriving from muscles. Penis covered 

 by a cuticula, it is very different from those hitherto described in Rotifera. Weber describes 

 it as follows: »A la base du testicule et y faisant suite, nous voyons chez D. calcllitia un organe 

 en forme de navette, formé de deux bandes aplaties, concaves à l'intérieur et convexes a l'ex- 

 térieur, se réunissant et se terminant en pointe à l'extrémité postérieure du pénis. Les deux 

 bandes chitineuses sont la continuation de l'enveloppe du testicule; elles sont ilurcs, séparées 

 l'un de l'autre par un espace dans lec|uel se trouve le ])énis. Cette enveloppe chitineuse pro- 

 tège le pénis délicat et sert à forcer le cloaque de la femelle. C'est un étui proteeleur, droit, 

 long et étroit. Le pénis lui-même est fort mince et cylindrique; son orifice n'atteint pas 

 l'extrémité de l'étui, qui est ouvert, fendu dans toute sa longueur. Autour de cette gaine cornée 

 du pénis, nous voyons une gaine musculaire en fourreau et des muscles rétracteurs de cet 



