Kolpodea.'] infusomal animalcules. 587 



Body elliptical or reniform, compressed. An oblique wreath of 

 long cilia reaches to the middle, where the mouth, with its slight 

 tongue- like process, is situated. Found in the river mussel (Mya). 

 Size 1-2-lOth to 1-2 1 0th. 



Paramecium milium {Cydidivm milmm, M.) — Body small, ob- 

 long, trilateral ; rounded equally at both ends. In coloured water 

 the body is seen vibrating. Size 1-1 150th. 



Genus Amphileptus. — The double-necked Aniinalcides have 

 neither tongue-like process nor eye, but are provided with a pro- 

 boscis and tail. Body elongated, fusiform or lanceolate. In three 

 species the organs of locomotion are numerous cilia disposed in 

 longitudinal series ; in one, cilia are not visible, but in this the 

 flexible attenuated extremities of the body serve their office. In 

 some, the tail (foot) and proboscis (brow) are rudimentary. In five 

 species numerous digestive cells, filled with food, may be seen ; in 

 seven the mouth is distinct ; and in five of them a discharging 

 opening. All have a colourless digestive juice, except A. murgaritifer, 

 in which it is pale rose-red. Ova granules ai'e observable in seven 

 species, in one are green, in the others whitish. In four species a 

 contractile vesicle is seen ; in three sexual glands, which in two are 

 globular, double, and moniliforra in the third self-division, has been 

 observed : in one species it occurs transversely and longitudinally, 

 and in another transversely only. The figures of this genus were 

 engraved before I discovered Dr. Ehrenberg had not arranged his 

 illustrations according to the classification. 



Speaking of M. Ehrenberg's distribution of this genus, Dujardin 

 remarks, "this author whilst assigning as characteristic, the pre- 

 sence of a proboscis and tail, yet places among it, as species, animal- 

 cules without tail, and dilated or rounded posteriorly; and on the 

 other hand, ever seeking a distinctive character for his different 

 families, in the position of the anus, which he attributes to all his 

 enterodelous Infusoria, he has left in his genus Trachelius, several 

 species, which to us appear to belong to Amphileptus, and has him- 

 self several times transferred some species from one genus to the 

 other." 



The Amphileptus anser is taken by Dujardin as the type of a 

 genus termed Dilepttis, and A. meleagris of a genus LoxophyJlmn. 



