240 52 



Brachionus. 



Of the ten males ot Rotifers which Gosse (1856, p. 313) described and figured in his 

 famous work, the seven belonged to the genus Brachionus. Some of these seven species (B. 

 amphiceros, dorcas) are unquestionably only temporary forms of the same species. It is not 

 possible, from the description and drawings, to distinguish these species in the male sex from 

 each other. It is stated with regard to these males that the lorica is only feebly developed, 

 that the head is more or less conical, set with large setiform cilia all over the front, that 

 behind the front there are several lobes, with a red eye commonly on the truncate apex of 

 the posterior lobe. The body cavity is filled behind with a mass in the middle of which is 

 situated the group of opaque white granules, contained in an irregular bladder. The central 

 part is occupied by the spermatic sac, connected by a bottle-like neck with the head-mass, where 

 a distinct corrugation probably marks an orifice, closed by a sphincter, which leads to the 

 discharging duct. The spermatozoa are observed (about thirt\'). With the spermatozoa are 

 extruded many spicula-like bodies. The penis is thick and united to the foot, terminating in 

 a short truncate tube, the excretory organs are seen and described as a chain of irregular 

 masses, running down from the head to the posterior part of the body, extending down into 

 the penis-foot. 



Even if it is impossible to distinguish the ditTerent Brachionus males, which Gosse has 

 described and figured, he who has observed the males oi B. angularis and B. dorcas (= B. paid) 

 will unquestionably understand, that Gosse reaUy has observed and figured the males of these 

 two species. Quite correctly Gosse described the male of B. angularis as covered with a 

 tortoise-like lorica, and states that there is a conspicuous construction between head and body, 

 and that all internal organs are invisible, the interior being occupied by a vast number of 

 minute granules or globules, irregularly clustered. In contrast to this little opaque male 

 (length r.Jnth) stands the large, highly hyaline male of B. dorcas, measuring oJoth of an inch 

 in length and very well' figured (fig. IS — 19) and described. 



Hitherto the following Brachionus males have been observed : 



Brachionus pala Ehrhg GossE(1856,p.316,Tab. I,fig.2); Weber(1898,p.672, 



PI. 23, fig. 16); Plate (1886, p. 67, PI. 3, fig. 25). 



— urceolaris O. F. M. .. Cohn (1856, p. 470, Tab. 24, fig. S— 9); Weber 



(1888, p. 56, PI. 35, fig. 2; 1898, p. 678, PI. 23, 

 fig. 20); ToTH (1861, Tab. I, fig. 9). 



— Mülleri Ehrbg Gosse (1856, p. 319, Tab. II, fig. 20). 



— angularis Gosse ... Gosse (1856, p. 317, Tab. I, fig. 13 — 14). 



— Bakeri O. F. M Gosse (1856, p. 318, Tab. I, fig. 12). Rousselet 



1897, p. 328, PL 16. 

 rubens Ehrbg Rousselet (1907, p. 153, PI. 12, fig. 11). 



— quadratns Rousselet. Rousselet (1907, p. 150, PI. 12, fig. 7). 



— sericus Rousselet - . . Rousselet (1907, p. 149, PI. 11, fig. 4). 



— furculatus Thorpe (1891, p. 301); Rousselet (1906, p. 397, 



PI. XIV. fig. 5). 



I 



