456 THE ZOOLOGIST. 



30. Rotifer tardus, Ehren. — This Eotifer is easily identified. 

 The swollen segments of its body, its ungainly shape, rendered 

 dirty-looking by mud and other foreign matter adhering to its 

 sticky surface, and its clumsy movements are alone almost 

 sufficient to distinguish it from other bdelloids. So far, speci- 

 mens have been found in Chipperfield Common Pool and in 

 moss from Shire Lane, near Hastoe. On September 15th, 1913, 

 a specimen was obtained from Chipperfield Common Pool by 

 dredging at the bottom near the end of the plank walk. This 

 specimen was so thickly covered with foreign matter that the 

 longitudinal ribbing, which is a marked feature of the species, 

 was not at all clearly seen ; on the other hand, its dorsal 

 antenna, its thick foot passing into its body without any sign of 

 an abrupt juncture, and its rather stout and long rostrum were 

 conspicuous. On this rostrum were the eye-spots ; at first sight 

 these seemed to be elongated single spots, but closer examina- 

 tion showed that each consisted of two separate spots. On 

 October 16th, 1913, a specimen of R. tardus was obtained from 

 the damp and luxuriant growth of moss in the ditch on the 

 Bucks side of Shire Lane, near Hastoe. The more central parts 

 of the specimen were brown and the extremities colourless ; and, 

 although there was a quantity of foreign matter on its sticky 

 surface, its longitudinal ribbing was well shown. The eye-spots 

 were not so well seen as those of the specimen from Chipperfield 

 Common Pool, nor did they seem to be made up of separate 

 small ones. 



Except when these specimens of R. tardus expanded their 

 wheels and frontal column and swam about, their movements 

 were quite sluggish and clumsy. 



31. Rhinops vitrea, Hudson. — This is another Eotifer of 

 ungainly form. Several specimens of the species were obtained 

 from Bedmond Pool on April 11th, 1914, and from Hastoe Pool 

 on May 26th, 1914. When seen in dorsal or in ventral view, 

 they presented a symmetrical form, with the dorsal proboscis 

 widening out into the " shoulders" of the Piotifer, and the rest 

 of the animal narrowing gradually and passing without an 

 apparent break into the short conical and flabby foot which, as 

 well as the peripheral parts of the body of the Rotifer, was of 

 hyaline transparency. The foot, indistinctly jointed, carried 



