436 Mr. F. E. Beddard on a 



caused by reagents. The boundary-line of the micropyle is 

 perfectly continuous with the inner margin of the cyst- 

 membrane, and there is no appearance, at the point where the 

 clear spherical body is in contact with the cyst-membrane, of 

 any perforation of the latter. This structure is so very much 

 larger in this species than in Orthosi^ora^ that this statement 

 can be made with greater confidence, and it does not appear 

 to me likely that the preservation of the specimens in alcohol 

 is likely to have confused the relations of these parts, which 

 are entirely chitinous. The appearance of such an individual 

 as that represented in fig. 1 gives some colour to the view 

 that the structure in question is a funnel-shaped invagin- 

 ation of the cyst-membrane which opens into the interior 

 of the cyst ; but it is simply due to the optical effects pro- 

 duced by the position of the Coccidium. 



In other cases, where the micropyle is seen from above 

 (fig. 12) it presents the appearance of a free oil-globule con- 

 tained within the cyst. The second difference then between 

 the so-called micropyle of Orthospora and Coccidium perichcetce 

 (as I may term the species, perhaps both of them, which are 

 described in the present paper), is its very much greater size 

 in the latter. 



The third difference is that there are frequently two of these 

 structures present in a single cyst (see fig. 4) ; in these 

 cases they are not placed at opposite poles ; they may be 

 occasionally so placed, but I have noticed plenty of instances 

 where they are not. This fact will at once recall the appa- 

 rently similar structure of Eimeriafolciforni{s,\n which Eimer* 

 has noted the presence of two micropyles placed one at each 

 pole of the somewhat oval cyst. These structures have not 

 been described or figured by Schneider in his account f of 

 Eimer ia nova. 



Cyst-memhranes. — There are clearly two cyst-membranes 

 present in Coccidium perichceUe J ; the inner membrane is 

 much thicker in young stages than the outer membrane, 

 which is at that time very thin (fig. 9). Fig. 6 appears to 

 show a third, innermost, membrane, but I believe this appear- 

 ance to be due to the optical effect produced at a certain focus 

 by the inner membrane. 



The most remarkable difference, however, between the 

 cyst-membranes in this species and in Coccidium oviforme is 



* See Biitsclili, Bronu's * Tbierreich/ Bd. i. Protozoa, pi. xxxviii. 

 tig. 2 ft. 



t Loc. cit. p. 397. 



X These statements, as well as those about the micropyle, refer only to 

 the parasite of Ferichata annata. 



