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A New Male Rotifer {Metopidia solidus). 



By Walter Wesche. 



{Read June 2\st, 1901). 

 Early in January of the current year I obtained some weed 

 from a pond on Golder'.s Hill, Hampstead Heath, which I placed 

 in tap water. On looking over the water several fully grown 

 specimens of the rotifer Metopidia solidus were seen. The weed 

 soon decayed, and, as it did so, great numbers of this species 

 appeared ; the mature form was constantly found, and with it 

 several interesting immature forms. On Feb. 17th it was 



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Metoindia solidus. — Fig. 1. Dorsal view, ^. Fig. 2. Lateral view, ^. 

 Fig. 3. Dorsal view, ^ (another specimen). Fig. 4. Foot and 

 toes of ^ . 



my good fortune to find a male, and on the following evening 

 two more were met with. Like all male rotifers that I am 

 acquainted with, the specimen most carefully watched was 

 exceedingly restless, and quick in mcJvement, but after two 

 hours' confinement in a liv'e-box he obviously became moribund, 

 and anchoring himself by the toes, he gave me an opportunity 

 of more exactly observing him. The lower joint of the foot 

 is mostly kept deflected, both in swimming and resting, and 

 this renders it rather diflacult to obtain an exact measurement, 

 but I think -^\-^ inch (113 jx) may be accepted as fairly accurate. 

 This is the extreme length of the fully extended rotifer. 



