668 GARY N. CALKINS 



2. B. undulans St. The color is purple red; the peristome 

 does not reach to the middle of the body but is usually limited 

 to the anterior third, with a well-developed undulating mem- 

 brane attached to the entire posterior half of the left peristome 

 edge. One nucleus in the anterior half and one in the ' pos- 

 terior half, with or without a connecting strand of nuclear 

 material. 



Stein maintained that Perty's two species were neither new 

 nor distinct from one another, and interpreted Perty's 'mole- 

 cular rows' as the body stripings. Stein's B. lateritia was more 

 frequently seen, undulans only a few times and then in connec- 

 tion with numbers of lateritia. Biitschli regards Stein's undu- 

 lans as the same as Ehrenberg's Uroleptus musculus, appar- 

 ently ignoring the difference in the undulating membrane of 

 Stein's two species, but accepting Stein's characteristics as given 

 for B. undulans. Stokes, finally, has apparently described the 

 genus under the name Apgaria. 



While there is little difficulty in deciding upon the generic 

 name Blepharisma, the task is not so easy with the type species. 

 Stein has shown that Peity's two species cannot hold, while 

 the descriptions of Stein's own species, careful and detailed as 

 they are, cannot be traced back to any one type of Ehrenberg 

 or Miiller. Both his lateritia and undulans could be included 

 in Ehrenberg's Bursaria lateritia which in turn, might go back 

 to Miiller's Trichoda aurantiaca and T. ignita. Neither Miiller's 

 nor Ehrenberg's descriptions of these species were sufficiently 

 accurate to be recognizable today; similarly with all other char- 

 acterizations save those of Stein, where we have to decide as 

 to the validity of the two species lateritia and undulans. 



The essential differences in structure between the two species 

 given by Stein are in connection with the undulating membrane 

 and the macronuclei. In lateritia the undulating membrane 

 is said to be a mere bristle or cirrus-like structure inserted near 

 the mouth in the angle of the peristome, while in undulans, 

 the undulating membrane is much more extensive, extending 

 half way up the peristome left edge. The bristle or cirrus was, 

 probably, only the proximal edge of the undulating membrane. 



