Phil"dina€a.'\ INFUSORIAL animalcules. 663 



Dinocharis (fig. 455.) Muscles arc scon in the genera just named. 

 The nuti'itive apparatus consists of an cesopliagoal head, with two 

 jaws; in three genera these are double -toothed {zygogomphia) ; in 

 two the teeth are in rows {Juchogomphia.) In the four principal 

 genera the alimentarj' canal is filiform ; it is furnished "with a 

 bladder-like expansion at its commencement {trachelocystea), and 

 surrounded by a turbid cellular or glandular mass. In one genus 

 the alimentary canal is conical (coclogastrica), in the two African 

 genera it is unknov.Ti. In four genera the intestine has glands ; in a 

 like number, an ovarium and glands are present; a contractile 

 vesicle exists only in Rotifer and Phihdina, which, together 

 with Actinurus, are also sometimes viviparous. In Rotifer and 

 Phihdina portions of a vascular system are visible, in the form of 

 from nine to twelve transverse vessels ; the same genera, as also 

 Actinurus and Monolahis, have spur-like rcspiratoiy tubes. In 

 thirteen species red eyes are present, and beneath these organs only, 

 is nervous matter apparent. 



The genera are disposed as follows : 



proboscis and foot processes present Callidina. 



rotary organ peJiclcd Ilydrias. 



Eyes absent. | no proboscis or ' 

 horn-like processes ' 



Eyes present < 



. rotary organ not pcdioled Typhlina. 



C toes two Rotifer. 



foot having horn-like J 

 processes ] 



t toesthree Actinurus. 



foot without horn-like processes, I tit „ i v 



toes two ] Monolahis 



. two cervical Philodina. 



" The characters employed," says Dujardin, " by M. Ehrenberg, 

 for the distinction of his genera of Philodincea, have certainly too 

 slight a constancy to be admitted ; that author has himself seen the 

 red specks, which he calls eyes, vaiy in number and position in his 

 Eotifers. As to the appendages of the tail (toes), they are not 

 always alike -vdsible, although actually present, because the animal 

 does not extend them except at certain moments ; the central terminal 

 appendage — that by "v^'hich the Rotifers affix themselves to solid 



