184 BRITISH ENTOMOSTRACA. 



In Number 283 of the ' Philosophical Transactions' for 

 January and February, 1703, the same author gives a 

 description of a polype (the H^dra viridis of Miiller) 

 growing upon the lemna, or duck-weed, which calls forth 

 another paper from an anonymous correspondent, in 

 Number 288, for November and December, 1703, in 

 which the writer mentions his having frequently observed 

 the same polype growing upon insects, especially upon 

 " two sorts, of the crustaceous kind." Of these two 

 species of animals, which he states are monoculous he gives 

 figures, sufficiently correct to show them to be the Cyclops 

 quadricoruis and Diapiomiis Castor, the first being a tole- 

 rable figure, though the second is very indifferent. The 

 same writer also takes notice of a third animal of the 

 same family, which is much smaller, and like a shrimp, 

 but which he could never figure, evidently the Cantho- 

 camptus minutus. • 



Baker, in his 'Microscope made Easy,' 1743, makes 

 a few remarks upon the same animals, and copies the 

 figures from the ' Philosophical Transactions ;' and in his 

 'Employment for the iMicroscope,' 1764, he publishes a 

 letter from a correspondent, who gives a variety of details 

 with regard to the animal which Ijceuwenhoek describes, 

 finds great fault with his figure, but gives a much worse 

 one himself! 



De Geer, in his ' Memoires pour servir a I'Histoire des 

 Insectes/ vol. vii, published in 1778, is the next author, 

 I believe, who has entered into any details relative to this 

 family. He describes at considerable length, and figures 

 with tolerable accuracy, the Cjidops qitadricornis, and 

 confirms many of Leeuwenhoek's statements respecting it, 

 particularly the great difference between the young and 

 the old animal. 



Otho Eridericus Miiller * is the next succeeding author 

 who has particularly noticed the family. Previous to his 



* Zoolog. Dau. Prodrom., 1770; Eutomostiaca, seu lusecta Tcstacea, 

 &c., 1785. 



