1892.] MICROSCOPICAL JOURNAL. 275 



funnel ; the sides of the groove are thickly clothed with cilia, and 

 have a lip-like motion capable of opening out or closing the 

 groove more or less. 



The mastax, digestive organs, and vascular system appear to be 

 normal. The rami have four teeth and a number of ridges, which 

 get smaller and smaller ; these teeth and ridges were the first 

 structures observable in a developing egg. The cloaca is placed 

 high up on the dorsal side nearly on a level with the mastax. 

 The brain and two red eyes are conspicuous ; each eye consists of 

 a minute, clear, refracting sphere, seated on a hemispherical 

 cushion of red pigment. Four pairs of narrow bands of muscles 

 are attached to the head below the corona and run down over the 

 trunk to the extremity of the foot. The foot contains four sets of 

 long and well-developed glands, reaching into the body cavitv. 



Both C. volvox and Doss7iai-iiis lay eggs, but in C. njiicortiis 

 I have seen the fully-formed j-oung, with eyes and moving jaws, 

 within the mother, so that it is probable this species is vivip- 

 arous, like an Asplanchna. The clusters consist of very few indi- 

 viduals, from two to seven living together in a gelatinous secre- 

 tion ; although rolling freely in the water, the clusters are more 

 or less unsymmetrical. The size of the individual is i-ioo to 

 1-130 inch, which is very much smaller than C. volvox \ the 

 body is rather short, but the foot is short and does not much ex- 

 ceed the body in length. 



In October, 1891, I paid a second visit to Keston and collected 

 a large number of C. unicornis \ the colonies were more vigo- 

 rous than when first discovered and more numerous in individ- 

 uals, some of the larger ones having as many as twenty to twenty- 

 five individuals, but the majority of the colonies were smaller, and 

 they continued to present a more or less symmetrical appearance. 

 The single antenna, which is so conspicuous under a low power, 

 is found, when seen from the ventral or dorsal side under a high 

 power, to consist of two antenna? closely vmited. and inclosed in a 

 single sheath. The stout bristle resolves itself under a very high 

 power (i-io apochromatic water immersion) into two brushes of 

 very long and very fine seta^. and one belonging to each antenna, 

 as shown in Fig. 4. 



I have mentioned above that I have seen the young fully formed 

 in utero ; I have also seen it ijorn. One egg was Iving across the 

 body on the ventral side and filling fully one-third of the whole 

 body cavity. By degrees it was pushed toward the dorsal side, 

 and then gliding slowly past the stomach and intestine it came out 

 at the cloaca, which is situated high up on the dorsal side ; I 

 could see no trace of an oviduct, but it is evident that there must 

 exist one, otherwise it will be difficult to imagine how so-l.irge 

 an egg could find its way from the ventral side, past all the over- 

 lying viscera, to the cloaca at the opposite corner of the bodv 

 cavity. When laid the egg was fiillv mature, with jaws moving 

 incessantly, the ej-es distinct, and the cilia playing around the 



