142 THE ROTATORIA. <§. 131. 



Family : Monotrocha. 



Genera : Ptygura, Ichthijdium, Chaetonotus, Oecistes, Conochiius. 



Family : Schizotrocha. 



Genera : Megalot'i ocha, Tubicolaria, Stephanoceros, LacirMlaria, Melicerta, 



Floscularia. 



Family : Polytrocha. 



Genera : Entcroplea, Pleurotrocha, Hydatina, Notommata, Synckaeta, 

 Polyarthra, Diglena, Triarthra, Eosphora, Cycloglena, Theorus, Masti- 

 gocerca, Euchla7iis, Salpina, Stephaoiops, Squamella. 



Family: Zygotrocha. 

 Genera : Rotifer, Acthnirus, Ph'dodhm, Noteus, Amiraea, Brachionus. 



BIBLIOGRAPHY. 

 See the works already cited under Infusoria. 



ADDITIONAL BIBLIOGRAPHY. 



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

 in my notes, see the following : 



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

 thiere, in Wicgmanns Arch. 1846. 



Frey. Ueber die Bedeckungen der wirbellosen Thiere. Gottingen, 

 1848. 



UUdekem. Bull, de 'I'Acad. Roy. des So. 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- 

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



1 With Chaetonotus, and Philodma aculeata, spines. With Noteus, and Anuraea, th'Te are 

 tlie stniclurc uf IIil' skin Is iiuite different from spucieHi whose t'acrted sliin is rouslii^uL-d by iimumer- 

 Uiis ; fur iw surface bristled witli slilV points and al)le grauulatioua. 



