30 THE KOTIFERA. 



Genus PBOALES, Gosse. 



GEN. CH. Of moderate or small size; body generally cylindric, or larviform ; 

 ciliated face more or less prone ; brain clear ; auricles and tail wanting. 



This again is an extensive group, containing many species, some of them of familiar 

 occurrence, often obscure, of indefinite character, and hard to be distinguished. Some 

 are entozoically parasitic on other creatures. The vibratile cilia are disposed on a face, 

 along that side of the head which is more or less in the ventral plane. Their bodies are 

 usually litlie, soft, and versatile ; their motions rapid and various. 



P. DECiriENS, Ehrcnberg. 



(PI. XVIII. fig. 6.) 



Notommata decipieyis . . . Ehrenberg, Die Infiis. 1838, p. 431, Taf. Hi. fig. 6. 

 „ vermiailaris . . Dujavdin, Hist. Nat. Zooph. p. 648, pi. xxi. fig. 7. 



[SP. CH. Bodij cylindric, slender, icorm-like ; foot undeveloped; toes viinute. 



This much resembles a dipterous larva ; having a soft, flexuose, slender body, with 

 a rounded front, and two minute, conical toes, without any sensible foot. A large, oc- 

 cipital brain carries a red eye, distinct, though small ; a crystalline lens is conspicuous, 

 seated on, and partly imbedded in, the pigment-globule ; the latter much the larger. 

 (See Duj. loc. cit.) Near the front are two clear colourless granules, usually distinct in 

 the many examples that I have met witli. These may be readily mistaken for eyes 

 •when the animal is in motion. A mastax with trophi of normal form leads by a very 

 long and slender oesophagus to a cylindric alimentary canal, with usual accompaniments. 



I first found this in 1849, in waters near London both north and south. Since then 

 it has occurred repeatedly in various localities. When I saw my first example, it was 

 spinning round on its long axis. After a while it became less impatient, but still very 

 lively. It frequently bent itself up double, in the manner of a caterpillar, and occasion- 

 ally shrank up into a wrinkled, shapeless ball, remaining thus awhile quiet. Gliding 

 through the water by means of its rotatory cilia, its motion was not particularly rapid. 

 Though I have called the trophi normal, there is, in the form of the rami, a manifest 

 approach to these organs in Diglena. — P.H.G.] 



Length, -pj^ to -^^y inch. Habitat. Near London ; Epping Forest ; Birmingham ; 

 Stapleton Park, Yorkshire ; Dundee (P.H.G.) : pools : not common. 



P. FELis, Ehrcnberg. 

 (PI. XVIII. fig. 17.) 



Kotommala fclis .... Ehrenberg, Die 7n/HS. p. 431, Taf. lii. fig. 7. 



[SP. CH. Body cylindric, slender ; a large decurved fleshy proboscis ; eye very 

 large; trophi Diglcnoid ; foot stout ; toBi slender, p)ointcd. 



Of this httlc species, the slender tnuik is strongly fluted longitudinally. The curious 

 projection which Ehrenberg calls a horn, is a thick soft lobe of translucent flesh, which 

 ciu'ves down before the head, perhaps a tentative organ, and recals what we see in some 

 of the Diglena. So also do the pincer-shaped rami ; and, as in that genus, they are 

 capable of being rapidly and forcibly thrust forth, with a snapping action. The brain is 

 broad, and descends far ; it bears on its round extremity an eye so large that it occupies 

 fully half the diameter of the body. Yet it is seldom seen ; being a lens seated 

 transversely, and edgewise to the observer. The stomach too, with high lateral 

 shoulders, usually densely filled, hinders the observation, not only of the eye, but of all 



