INFUSORIA. 



47 



Schizosiphoii. Stylonichia mytilus, which is abundant in vegetable infusions, ilhistrates 

 a type of structure somewliat common in this sub-order : the presence of stylets and 

 hooked hairs. It is elongate, elliptical, with a slight left-handed curvature, taperin^ 

 backwards from the centre ; two of the fine anal stylets project beyond the body, the 

 three long caudal set* are radiating ; there are five claw-like ventral stylets and several 

 frontal ones. Euplotes also includes well-known forms. They differ from those of the 

 last-mentioned, first in being encuirassed, second in the styles, although frontal, ventral 

 and anal are represented. 



Okder III. — TENTACULIFERA. 



It remains to introduce some typical forms of the order Tentaculifera. Compared 

 with the orders already described, the specific forms are comparatively few, but their 

 remarkable structure renders them as interesting. Until recently the Tentaculifera 

 were not recognized as a distinct order of Infusoria. By Ehrenberg they were arranged 

 with the diatoms and desmids. Stein in his earlier publications regarded them as 

 developmental stages of the Vorticellidie. To Claparede and Lachmann is due the 

 honor of pointing out their true nature. The term Tentaculifera was proposed by Prof. 

 Huxley, while Suctoria, — the name applied by Claparede and Lachmann,- — has, by 

 Kent, been retained for the division in which the tentacles are wholly or partly suctorial. 

 He has also called those whose tentacles are non-suctorial, but merely adhesive, Actin- 

 aria. The animalcules in tlieir adult life bear neither flagella nor cilia, their embryos, 

 however, are ciliate. Maupas claims that adults of some Podophrym and all the Sphce- 

 rophryce are able to resume their cilia and become free. Their food is taken by means 

 of tentacles developed from their cuticle, the tubular sort terminating in a sucking disc ; 

 and the protoplasm of the body extending into the tentacles. When an infusorian is 

 caught by an Acineta and held at the extremity of one of the tentacles, a rupture is 

 produced in the cuticle of the victim at the point of contact. The axillary substance 

 of the tentacle penetrates this perforation. The tentacle now increases in size, due, 

 doubtless, to a flow of sarcode from the body of the Acineta. On penetrating the body 

 of the prey this sarcode, according to Ma>ipas, mingles with the substance of the vic- 

 tim's body, and then returns to its place of departure. A nucleus and one or more con- 

 tractile vesicles are usually present. The Tentaculifera increase by division and by 

 budding. 



StJB-OrDER I. — SUCTOKIA. 

 The species of Acineta and its allies are numerous ; the animalcules have many ten- 

 tacles, while in the genera Rhyncheta and Urnula, there are only one or two ; all arc 

 stalked, some are loricate, others naked. The Sphoirophryce are free forms, frequently 

 parasitic within other Infusoria. Sphcerophrya sol is found in Faramecitim aurelia, 

 S. stentorea in iStentor roeselii, etc. They are spherical, with suctorial tentacles scat- 

 tered over their surface. The earlier stages of the next genus are free, and may be 

 taken for /Sphmrophryce, and the latter in turn have been mistaken for the acinetiform 

 embryos of their hosts. The genus Podophrya also includes many species. They dif- 

 fer materially f)-om the preceding in that they are pedicillate, while some species differ 

 from others in having the suctorial tentacles in fascicles. To the latter belongs P. 

 quadripartita, which has been often seen by the writer on the stalks of Epistylis pilicu- 



