452 THE ZOOLOGIST. 



to the water, and some time afterwards the greater part of it 

 was poured off. The residue was then examined by means 

 of the microscope, and an Asplachna of great transparency was 

 noticed, but it was by no means in a suitable state for specific 

 identification, contraction having taken place. Within it was 

 a small Eotifer, apparently a Brachionus. This Asplachna is 

 the only one so far obtained, and is conveniently mentioned here 

 because it was found in the northern section of the canal, the 

 peculiarities of the Rotiferan fauna of which are being considered. 

 It seemed to be a specimen of Gosse's A. brighhvellii. Beyond 

 this it will serve no useful purpose to say anything further, but 

 I hope to obtain specimens of Asplachna under conditions 

 favourable for satisfactory identification, in which event the 

 species so determined can be fully described. For the present 

 three species of special interest from various parts of the canal 

 will be described, viz. Brachionus quadratus, Rouss., Dinocharis 

 tetractis, Ehren., and Philodina citrina, Ehren. 



25. Bracliionus quadratus, Rouss. — A fine specimen of this 

 species was obtained by dredging along a distance of about one- 

 eighth of a mile in the canal south of Tring Station on May 26th, 

 1914. The surface of the lorica presented a peculiar appearance; 

 it was somewhat opaque, but, reflecting from many minute areas 

 numerous pencils of light, the whole effect was similar to that 

 obtained by reflecting light from a dark coloured plate of 

 crackled or frosted glass. The length of the lorica was about 

 Too m - I^ 3 s * x ora l spines, of characteristic form and arrange- 

 ment, were very conspicuous. A brilliant red eye-spot was seen 

 situated rather far back from the oral end, and on or near the 

 central line of the lorica. The Rotifer was very prone to anchor 

 itself after the manner of Noteus quadricornis, keeping its foot 

 and the hinder part of its body out of sight. When in this 

 position the trapezoidal form of its lorica was well seen. Occa- 

 sionally the Rotifer exposed to full view its dorsal surface, 

 remarkable for its large size and somewhat square form. On 

 account of its peculiar movements it was difficult to obtain a 

 good view of the foot, which was seen, however, to be long and 

 unusually thick and strong. 



26. Dinocliaris tetractis, Ehren. — From the water which 

 yielded the single specimen of B. quadratus, just described, 



