o/ 



SYSTEMATIC HISTORY OF THE INFUSOEIA. 



characters and distinctions of species, along Ts^th the names he has assigned 

 them. 



The genus Opalina was constituted by Pm^kinje, and has been generally 

 accepted. Dujardin introduced 0])alinci into his family Leucophryina along 

 with Leucoplvnjs and Spathidium, and characterized that family as of a com- 

 pressed-oval or oblong figure, clothed with closely-arranged ciHa in regular 

 series, and apparently destitute of a mouth. 



Opalina Ranarum = Bursaria Rana- 

 rmn (E.). — The mouth described by 

 Elirenberg in this species is merely a fold 

 of the sm-face, as may be proved by add- 

 ing a dilute solution of iodine, of alcohol, 

 or of acetic acid, which will cause the 

 animal to swell up aud evenly distend 

 the entire surface. Stein could find no 

 nucleus. This species is common in the 

 intestine and bladder of frogs. Perty 

 makes it to include besides Bursaria 

 Ranarum (E.), also B. Entozoon, B. 

 Nucleus, and probably B. intestinalis. 



O. Planariarum (Siebold) = O. poly- 

 morpha (SchiQtze). — The body has the 

 form of a long cylindrical sac, pointed and 

 wedge-shaped posteriorly, and expanded 

 iu front as a remarkable semicircular 

 disc, by the central part of which it ad- 

 heres to the surface of the intestine it 

 occupies, the border being crowmed with 

 a wreath of long cilia. The actual point 

 of attachment appears destitute of cilia ; 

 but the posterior sm-face is thickly studded 

 with shorter ones. The contents consist 

 of a homogeneous molecidar substance, 

 with numerous interspersed hyaline 

 spaces. A long pulsating vesicle (or, 

 from its length, a vessel) and a nucleus 

 are also seen ^vithin the interior. The 

 pulsating vessel extends to the extreme 

 point of the body behind, just beneath 

 the integment, but not in union with it, 

 aud terminates on the anterior side of 

 the semicircular process in front. Its 

 walls are structureless and transparent; 

 aud by its alternate contractions and ex- 

 pansions it pushes forth the contained 

 water alternately from each end. The 

 position of the nucleus in the interior is 

 not constant ; it consists of a finely 

 granular mass containing some larger 

 granules, and is sharply defined. Fission 

 is transverse, the nucleus and contractile 

 vessel dividing consentaneously Muth the 

 body. Stein could not discover the 

 orifices at the end of the pulsating vessel 

 described by Schidtze. Maximum size 

 1-3'" in length ; breadth 1-20'" ; length 

 of nucleus 1-25"'. 



0. Lumhrici (Stein). — Is represented 

 bv Leucophrys striata and L. nodulata 

 (l)uj.), the latter being an altered form 



of the former, dependent on iiTegular 

 endosmosis of the water in which it is 

 placed. Transverse fission occurs in aU 

 sizes, which vary from 1-60"' to 1-14'". 

 Parasitic in earth-worms (Ltmibrim). 



0. armata (Stein) = O. Lumhrici 

 (Duj.). — Has an oval compressed figm-e 

 like the foregoing, from which it differs 

 by ha\ung a strong, horny, micinate pro- 

 cess at the anterior extremity, on the 

 under surface of the body, and, extending 

 fi-om it, a fold of the sm-face. The other- 

 Tvdse homogeneous and finely granular 

 nucleus is remarkable by exhibiting a 

 greater or less number of solid oval 

 nuclei and elongated rods. Specimens 

 of this species are peculiar by their uni- 

 formity of size, which somewhat exceeds 

 that of the largest O. Luinhrici, being 

 from 1-12"' to 1-8'" : hence Stein pre- 

 sumes that O. armata is nothing more 

 than a fm-ther developed phase of 0. 

 Lumhricij from which it diners only in 

 size and in the presence of the prehensile 

 apparatus. He surmises fm*ther that 

 this and other OpaUncB may be members 

 in the chain of development of worms. 



0. A))odontce (Stein) = Leucophrys 

 Anodontce(E.). — Mouthless, oval, turgid, 

 transparent ; ciliated equally throughout. 

 1-36'". Parasitic in Anodofita and 3fy- 

 tilus edulis. 



0. branchiaru?n. — Is characterized by 

 its very lar^e nucleus, which equals in 

 volume the half of the entire organism. 

 Its contom* is also similar ; and it might 

 be taken for an imprisoned animal. 

 Common in the ovisacs of Gammarus 

 Pulex. 



O. lineata (Schultze). — Is without 

 uncini, and has, like the last, a very large 

 nucleus. In Nais liitoraUs (see Schultze's 

 work Beitrciye zur Naturgeschichte der 

 Turhellarien, Clreifswald, 1851, p. 69). 



O. Ndidos (Duj.) (XXVI. 28, 29).— Is, 

 like the preceding, unfui-uished with a 

 prehensile apparatus. Figm-e oval, or 

 very elongated and nearly cylindrical, 

 longitudinally and transversely striated : 

 the fold extends from the anterior ex- 

 tremity nearly to the middle. Numerous 

 clear spaces in the interior, irregularly 

 distributed. 1-22'" to 1-11'". Parasitic 



