THE OPALINID CILIATE IXFUSORIANS. 439 



like the body. In occasional examples a protuberance is dichotom- 

 ously branched. After 18 hours in salt solution the appearance is un- 

 changed. The protuberances are said to be formed by a split appear- 

 ing in the body, the tip of the protuberance being the last portion, ex- 

 cept the persistently attached base, to separate from the body. Von 

 Linden discusses the question Avhether these are atypical locomotor 

 organs, or are pathological, or are connected with division, inclining 

 to the latter interpretation, though complete separation was not 

 observed. [These phenomena seem to be similar to, though more 

 exaggerated than, those Metcalf (1909) described for Opalina ohtrl- 

 goncb when the presexual mania for fission begins.] Von Linden's 

 figures look much more like palina ranaritmWYAW C e pedea dlmuliatn. 

 The arrangement of the nuclei in longitudinal rows (see his figures 1 

 and 2) is different from anything I have observed in any Cepedea or 

 Opalina. 



Cepede (1910) gives full reference to the discussions of the tax- 

 onomy of the true Opalinidae and the other Ciliata Holotricha 

 Astomata. There is no detailed treatment of the true Opalinidae in 

 Cepede's own discussion. This fine paper very clearly shows that the 

 true Opalinidae are not closely related to the other astomatous Ciliates. 



Cleland and Johnston (1910), '•'■Opalina sp.*' This degenerate 

 ciliate infusorian is comparatively common in the intestine of Hi/la 

 aurea., H. caei^lea., Limnodynastes peronii and L. dorsalis. [Of 

 course these parasites w^ere not true Opal'mae according to our jiresent 

 taxonomy but probably ProtoopaJina. The record from Hyla 

 caerulea is new.] 



Faure-Fremiet (1910) refers to paramyelin in ''•Opalina^'' as a 

 product of degeneration of the cytoplasm, a combination of soluble 

 and insoluble albuminoids and certain molecules of fatty acid ; refers 

 to the work of Balbiani, Kunstler and Gineste, Gineste, and especially 

 Metcalf, upon cytoplasmic spherules. 



Hartman (1910) compares the ectoplasm of T richonympha ''^hert- 

 wigi " with that of " Opalina'^' also discusses gamete formation in the 

 two genera. He rejects the idea of genetic relationship. 



Nagler (1910) refers to Schouteden (1907). 



Cockerell (1911) mentions '^Opalina sp." as occurring in "the 

 frog" in Boulder County, Colorado, United States of America. 



Doflein (1911), in this fourth edition of his textbook, gives a brief 

 description of the structure and life history of Opalina ranarum. 

 Brief reference is made to the cilia, to the presence of true [?] gly- 

 cogen and fat and to the excretory organs. The Opalinidae are 

 classed primitive members of the Ciliata Holotricha. The ectoplasm 

 is erroneously stated to be homogeneous, while the endoplasm is granu- 

 lated. Metcalf is mistakenly quoted as saying that Opalina mnwnim 



