662 DESCEiPTioN OF {VolygasMca , 



Laceymakia tornatilis. — Neck retractile, sometimes disappearing 

 entirely, presenting then only the cilia croMTiing its extremity. 



L. farcta. — Flask-shaped, with a short neck. Found in ditch- 

 water about Paris. Length 1 -260th. 



Genus Leucophkys. — Body with vibratilc cilia, covering its whole 

 surface ; mouth obliquely terminal, without teeth. From the ob- 

 liquity of the mouth the upper part appears like a lip. The cilia 

 which cover the body, are short and disposed in rows ; those around 

 the mouth are longer, and produce very powerful currents. In 

 swimming all the species revolve ujDon the longer axis. A serpentine 

 alimentary canal (with numerous grape -like stomach-cells, more than 

 fifty), terminating at the opposite extremity to the mouth, is present. 

 In three species, numerous ova granules are observed, and in some, 

 one or two globular glands and simple contractile bladders. Transverse 

 and longitudinal self-division have been observed. 



Leucophrys forms, in the system of Dujardin, with Spathidium and 

 Opalina, the family ' Leucophryens ; ' characterized by having an 

 oval or oblong depressed body, covered with cilia densely, but regu- 

 larly disposed. They have no evident mouth ; if one be present, 

 it can only imbibe fluid, for foreign solid particles are not to be found 

 in their vacuolae ; hence they probably live only by absoi-ption. Most 

 of them are parasitic in Annelida and Batrachia, and soon perish in 

 pure water, like Helminthoid (tape) worms. In Opalina, an anterior 

 oblique cleft probably indicates a mouth. Dujardin says — '' It is to 

 the genus Bursa/ria that Ehrcnbcrg has transferred most of the true 

 ' Leucophr yens,' in conjunction with other Infusoria having a very 

 distinct mouth." 



Dujardin' s characters of Leucophrys are : — Body depressed, ovah 

 or oblong, equally rounded at the two ends, covered by long, very 

 numerous, vibratile cilia, in parallel rows; no mouth — " I have 

 restricted the term to animalcules parasitic in Zumlrici ; hut should 

 probably include the form met with by Ehrenberg in the Anodo7ite." 



Jj. patula {Trichoda patula, M — Bursaria patula, Duj.) — Body oval, 

 campanulate, turgid, as shewn in fig. 276, 277. It is sometimes 

 quite pellucid, at others of a whitish colour ; mouth ample and 

 gaping ; the stomach-cells arc very large, and fill themselves in an 

 irregular manner. When the animalcule is quiet, the passage of the 



