NOTES ON SOME CANADIAN INFUSORIA. 305 



of the posterior half ; whereas in my form they are almost at right 

 angles, and are more like Engelmann's description, "not quite S- 

 shaped." 



(2) The situation of the anal aperture. 



(3) The presence of two contractile vesicles. 



(4) The presence of terminal setae distinguish it from C. and L's 

 form, but in this particular it resembles those of Engelmann and 

 Stein. 



(5) The granules of the external portion of the protoplasm are 

 arranged in rows so as to give the borders of the body a striated 

 appearance, one stria apparently corresponding with each cilium. 

 This appearance is particularly noticeable, and is not represented in 

 any of the descriptions above referred to, and it may certainly be 

 concluded that it was not present. 



(6) The nucleus (n) is situated near the pharynx, and is ovoidal, 

 with an endoplastule. In this it resembles Stein, but differs from 

 the other observers. 



(7) The peristome field does not bend round the body as repre- 

 sented by Stein and C. and L., but merely runs obliquely downward, 

 being expanded at the top. This is dependent on the lesser extent 

 of the twisting in my form. 



As regards the size of my form, it ranges from 0.17-0.19 mm., 

 while Engelmann's measured 0.15 mm., and, according to Kent, 

 Stein's (?) measures ^Ju ^ of an inch, equivalent to 0.08-0.3 mm., 

 a sufficiently large range to include almost anything, but which may 

 be explained by the existence, according to Stein, of three distinct 

 forms. Of the pharyngeal cilia, I can say nothing, not having suffi- 

 ciently studied them. 



Taking into consideration these various points, I think the form 

 under observation was sufficiently characterized to be denoted a new 

 species, but so much variation occurs in the descriptions of M. sig- 

 moides, as given by different observers, that I do not feel justified in 

 giving my form a name, until by renewed research I have fully 

 satisfied myself of its specific distinctness. 



SCYPHIDIA INCLINANS, D'UDK„ 



The genus Scyphidia belongs to the solitary, sessile Vorticellidce, 

 and attaches itself to foreign objects by means of an acetabuliform 

 organ. Considerable doubt prevails as to the true position of many 



