238 50 



lies the mouth; between the two wreaths laterally two lobes carrying bunches of 

 cilia. The proboscis itself at the corners with two bunches of strong cilia; itself on 

 its whole under surface covered with a coating of very short fine hairs. A fully 

 developed alimentary canal with well developed mastax, furnished with trophi of 

 quite the same structure as in the female; a rather short oesophagus, a large stomach 

 with thick walls; to them are attached two coneshaped, gastric glands. There is 

 further a conspicuous intestine, but I have not been able to see any anus. Like 

 RoussELET I have seen the jaws move. There is a large brain, sending off nerves 

 to the proboscis and dorsally to the dorsal antenna; two lateral antennæ are present. 

 In the proboscis there are, as in the female, two red eyes, furnished with lenses. 

 There are two lateral canals, carrying four, perhaps five, pairs of vibratile tags. I 

 have not been able to see any contractile vesicle, as observed by Rousselet. There 

 is a large testis with two pairs of prostata glands ; ductus seminalis long, coated with 

 cilia and opening in the hind part of the first foot joint, carrying a double row of 

 cilia, second foot joint with two long foot glands; two very short toes. There are 

 nine transversal muscles, and a verj' complex system of longitudinal muscles for the 

 wlieel-organ, the foot, the penis and the testis. The course of these muscles will 

 best be studied in the figure. Size of male 300 — 360 /i, of female 360 — 400 fi. 



R. vilrea is found in about ten small ponds, all rich in organic matter and verj' 

 often of a green colour; a few times I have also met with it in the pelagic regions 

 of peat bogs. It is a spring form which appears in the middle of April often disap- 

 pearing already in May, lying all the rest of the year as resting eggs. 



Notops brachionus Ehrbg. 



Male: Hudson-Gosse: 1889 II, p. 12. 



Montet: 1815, p. 320. 



Tab. X, fig. 5—6. 



HuDSON-GossE (1889ii, p. 12, PI. XV, fig. 1 b) figure and describe the male. 



It is very unlike its mother in shape and size; a side view shows that the head slopes 

 back to a hump on the apex of which is a bunch of tactile setæ. A nerve-thread from the 

 nervous ganglion passes to these and lies between two fine muscular fibres. A moderately sized 

 sperm-sack ends in a ciliated penis, just above the foot, which contains two large club-shaped 

 glands. Close to the sac is a small contractile vesicle, the lateral canals of which can be 

 traced on either side of the ventral surface. 



Montet (1815, p. 320, PI. 12, fig. 31) gives a figure of the male but no de- 

 scription at all. He has seen the testis, the foot glands and excretory organ, the 

 wheel-organ is represented as a circle of cilia with three hair-pads on the disc and 

 two strong tactile hairs. As far as I can see two small tubercle-like protuberances 

 without cilia are present. There is a rudiment of the alimentary canal containing a 

 round body (most probably an oilglobule). 



Description: Rody almost broadest anteriorly, tapering behind with a peculiar 



