142 THE -ROTATORIA. § 131, 



Family: Monotrocha. 



Genera : Ptjjgiira, IchÜiydium, Chaetonotus, Oecistes, Conochilus. 



Family : Schizotrocha, 



Genera : Megalotrocha, Tubicolaria, Stephanoceros, Laciradaria, Melicerta, 



Floscularia. 



Family : Polytrocha. 



Genera : Enteroplea, Pleurotrocha, Hydatma, Noto?nmata, Syjichaeta, 

 Polyarthra, Diglena, Triarthra, Eosphora, Cyrjoglena, Thecrus, Masti- 

 gocerca, Euchlcmis, Salphia, Stephanops, Squamella. 



Family : Zygotrocha. 

 Genera : Rotifer, Actimcrits, Philodina, Noteus, Anurae.a, Brachionus. 



BIBLIOGRAPHY. 



See the works already cited under Infusoria. 



ADDITIONAL BIBLIOGRAPHY. 



Besides the writings of Brightioell, Huxley, Leydig, and others, quoted 

 in my tiotes, see the following : 



O. Schmidt. Versuch einer Darstellung der Organisation der Räder- 

 thiere, in Wicginanns Arch. 1846. 



Frey. Ueber die Bedeckungen der wirbellosen Thiere. Göttingen, 

 1848. 



D'Udekem. Bull, de '1 'Acad. Roy. des Sc. de Belgique, XVIII. 1, 



1851. , . . . . - 



See also the 'new edition of Pritchard's Infusoria, given under Book 

 first. — Ed. 



CHAPTER I. 



Cutaneous system. 



§ 131. 



Nearly all the Rotatoria are covered with a smooth, hard skin,^' which 

 is thrown into folds by the contractions of the subcutaneous parenchyma ; 

 at the anterior extremity only, it is very delicate, and covered with vibra- 

 tilc organs, which also move to and fro with the parenchyma. With many, 



1 With Chaetonotus, and Philodma aculeata, spines. With Noteux, and Anuraea, there .are 

 the structure of the skin is ((uite clilVerent from species whose faceted skin is roughened by iuuumer- 

 Uiis i for its surface bristles willi still points and able granulations. 



