820 ORDER TENTACULIFERA-SUCTORIA. 



Podophrya quadripartita, C. & L. PL. XLVI. FIG. 18. 



Body more or less ovate, tapering posteriorly, the anterior extremity 

 divided into four blunt rounded lobes, each of which bears a fascicle of 

 tubular suckers ; pedicle elongate, from one to one and a half times the 

 length of the body, expanding slightly towards its point of junction with 

 the body ; contractile vesicles varying in number from one or two to as many 

 as five or six ; endoplast oval, central. Length of body 1-300" to 1-200". 



HAB. Fresh water, on Epistylis plicatilis ; also attached to various 

 water plants and to Paludina and other fresh-water Mollusca. 



This form is identical with Stein's originally supposed Adneta-pha.se of Epistylis 

 plicatilis, afterwards receiving from him the name of Acineta quadriloba, but which 

 has necessarily to give place to the prior one of Claparede and Lachmann here 

 employed. Internal embryos of two sizes are, according to Claparede and Lach- 

 mann, developed in this species : larger ones which enclose a portion only of the 

 parent endoplast, and are liberated, according to Biitschli, through a specially 

 developed orifice, as in the case of Dendrocometes paradoxus ; and smaller ones, 

 to the number of sixteen or twenty, produced through the subdivision of the entire 

 endoplastic mass. In both cases the free-swimming gemmules at the time of libera- 

 tion exhibit a peritrichous type of ciliation, having an equatorial girdle supplemented 

 by an anterior tuft of cilia. The number of contractile vesicles which characterize 

 the parent form are found to be hereditarily represented in this embryonic phase. 

 The endoplast, at the time of partition, as observed by Biitschli, exchanges its 

 customary granular structure for a striate or fibrillate one, assuming its normal aspect 

 again after the birth of the embryo. Among the innumerable examples of this 

 species developed on a species of Conferva, recently remitted to the author by Mr. 

 Badcock, and referred to in the account given of Trichophrya epistylidis, it was 

 observed that the posterior moiety of the body was in many instances very attenuate, 

 not exceeding twice the diameter of the adjacent pedicle, and while in some cases the 

 transition from the thick anterior to the attenuate posterior region was abrupt, in 

 others the attenuation was gradual and uniform. Specimens preserved with a one 

 per cent, solution of osmic acid were found to retain their characteristic form in a 

 most remarkable manner, the central ovate endoplast being furthermore by the 

 application of this reagent most conspicuously developed. In their earlier pedi- 

 cellate condition the zooids of this species possess but a single fascicle of tentacles 

 which is shortly replaced by two, the full complement of four such bundles being 

 characteristic only of the adult state. The suggested relationship of Trichophrya 

 epistylidis to Podophrya quadripartita is discussed in the account given of that 

 species. 



Podophrya elongata, C. & L. PL. XLVIII. FIGS. 21 AND 22. 



Body elongate, subfusiform, five or six times as long as broad, bearing a 

 fascicle of suckers at the anterior extremity, one on each side at the posterior 

 extremity, and two oppositely disposed lateral groups ; pedicle thick, even in 

 width, longitudinally striate and often transversely plicate, usually about 

 one-third the length of the body, but occasionally greatly exceeding these 

 proportions ; contractile vesicles multiple, one larger one frequently deve- 

 loped near the apical extremity, and other smaller ones irregularly distri- 

 buted; endoplast band-like, vertical. Length 1-120". 



HAB. Fresh water, on the mollusc Paludina vimpara and various 

 water plants. 



