ON FURTHER OBSERVATIONS ON MALE ROTIFERS. 507 



and some specimens tliat we should describe as very short A. 

 aculeata or long A. brevispina. Several of the A. brevispina 

 females carried eggs; but one which particularly attracted the 

 attention of Mr. Wesche, had two, which appeared rather smaller 

 than the ordinary eg^. This female was isolated, and twenty- 

 four hours later was seen with the lower egg-shell empty, and 

 the male figured (Fig. 2) was seen swimming. On the next day 

 a dipping from the same water contained another male, which 

 was identical with that hatched out, and Mr. Wesche was thus 

 •enabled to say with certainty that it was also the male of 

 A. brevispina. 



Dr. Plate gives a descrijotion of the male of A. aculeata Ehr., 

 "but no figure. As he never succeeded in fixing this animal, his 

 observations are necessarily incomplete, but we gather from his 

 remarks that it presents no striking character to differentiate it 

 from A, brevisjnna ; indeed, most observers are of opinion that 

 A. brevisjnna Gosse, A. aculeata Ehr., A. tecta Gosse, and 

 A. curvicornis Ehr. are all varieties of one species. Although 

 this view would seem to be confirmed as regards A. brevis2nna 

 and A . aculeata by our finding them in company together with 

 intermediate specimens, we have thought it desirable to describe 

 the male now found as the male of A. brevisjnna, it having been 

 hatched from an Qgg carried by a female of that form. It is 

 possible that a more complete examination than has yet been 

 made of the male of a typical ^4. aculeata may reveal some reliable 

 distinction at present unsuspected. 



A very strong superficial likeness exists between the male of 

 A . brevispina SiTid. ihQ male of Triarthra longiseta ; but examina- 

 tion with high powers dispels this. Tr. longiseta has no lorica 

 or chitinous case to the foot, but has glands to the lateral 

 antennae, which are very well marked. The points on which 

 they agree are the general shape, the eye, the absence of toes, 

 and the setae upon the extremity of the foot. This likeness in 

 the males suggests a common parentage, although that very 

 important organ, the mastax, differs considerably in the females 

 of these two species. 



The male oi Pterodina 2)citina Ehr. has several points of interest. 

 Like the female, it has two frontal eyes, and the antennae are 

 situated in the same places ; but its appearance otherwise is quite 

 dissimilar. It is vermiform in shape, and swims somewhat after 



