W. WESCHE ON MALE ROTIFERS. 327 



A resting egg has, however, been seen, and I have myself observed 

 one in the moss Rotifer, Callidina plena Bryce.* 



The subject is full of uncertainty and complexity, but we might 

 have here a very rare " reversion to an original type." If that 

 were so, it would only be at long intervals that a male would be 

 seen, and that male would be of the lowest type, indistinguishable 

 from an infusorian without the most careful examination. 



We now come to the second male on my list NotoTn'niata naias 

 Ehr. I found this male as far back as January, 1894. 



The general shape is fusiform, with a slight tendency to 

 angularity. The head is well separated from the body, which is 

 long in proportion to its breadth and distinctly annulated. The 

 foot is long with four annulations. The toes are identical with 

 those of the female, each furnished with a big gland which extends 

 into the body some distance beyond the orifice of the penis. The 

 cilia are moderately long, with several indistinct setae. The 

 brain is large, and retracted by two powerful bifurcate muscles. 

 The eye is very large, dark red, standing out from the brain 

 (as in $ ), and there is a shght constriction where it joins the 

 brain. The dorsal antenna seemed placed very much forward on 

 the brain, but was not distinct. The lateral antennae were quite 

 clear, and on the lower part of the body. Below the brain was 

 a granular mass, and adjoining were some nebulous glands which 

 seem to be the remains of the digestive organs. The vascular 

 system was distinct, but no contractile vesicle could be seen. 

 The spermatheca was very large, extending well into the middle 

 of the body. 



Size j-^" = 212/>t. 



Habitat, pond at Neasden. Seen in January, 1894, and 

 March, 1902. 



The third male is that of Notops hyptopus Ehr. (The generic 

 name Notops is now altered to Gastropus by Dr. Weber.) The 

 male has much the same shape as the female, i.e., a rather 

 globular sack. The head is defined by folds of skin which can 



* See, however, note, p 324. 



