434 Mr. F. E. Beddavd on a 



stated that Coccidia are only found parasitic in Vertebrates, 

 Myriopods, Turbellaria, and Mollusks ; I am able now to extend 

 this statement, and to add earthworms to the list of animals 

 which are known to harbour Coccidia. I have made a prac- 

 tice of examining all the earthworms which pass through my 

 hands for Gregarines ; 1 have never as yet detected Coccidia 

 in any genus except Perichceta ; in two species of that genus 

 I have noticed these Gregarines, viz. in Perichoita novce- 

 zelandiw^ and in P. armata f ; in both species they occupied 

 the same part of the body, viz. the perivisceral cavity. 



In both cases the Coccidium differs in certain particulars 

 from any Coccidium that has been hitherto described ; it 

 seems also possible that the Coccidium which infests Peri- 

 ch(eta novce-zelandice belongs to a different species from that 

 which infests Perichceta armata ; upon this point, however, 

 I cannot be certain. 



I could discover only a few examples of Coccidium in Peri- 

 chata novce-zelandice J and therefore some stages may have 

 been wanting which would, if present, have sliovvn the species 

 to be identical with that inhabiting the body of PerichcBta 

 armata. The characteristic Gregarine of the first-mentioned 

 Perichceta^ was so numerous that there was perhaps no room 

 for the Coccidium to multiply very freely. 



On the other hand, the Coccidium of Perichceta armata, 

 when it occurred at all, which was very rarely, was extremely 

 abundant ; I have been able therefore to get together some 

 drawings, which are reproduced in PI. XV., and which illus- 

 trate some of the principal phases in the life-history of the 

 Coccidium. The majority of the figures in the plate illus- 

 trate the Coccidium of Perichceta armata ; fig. 16 refers to 

 the Coccidium of Perichceta novce-zelandice. 



In both cases the parasite has the form which is charac- 

 teristic of Coccidium^ that is to say it is oval or rather egg- 

 shaped, with slightly flattened sides. Certain individuals, for 

 example those represented in figs. 10, 11, are hardly distin- 

 guishable from Coccidium oviforme §. The cell-contents are 

 granular, with very coarse granules, and there is no differentia- 

 tion into endo- and ectoplasm ; the cyst-membrane is distinctly 

 double in some cases (fig. 9), less distinctly double in others 

 (fig. 10). 



* I have not yet described this species, -n-hich I owe to the kindness of 

 Mr. W. W, Smith, of Ashburton, New Zealand. 



t The specimens of this worm, in which the Coccidium occurs, were 

 kindly seut to me from Borneo by Mr. Everett. 



X See ]'. Z. S. 1888, pt. iii. 



§ For an account of this parasite see ' The Parasites of Man ' (Leuck- 

 art), translated by W. E. Hoyle, Edinburj^h : p. 203 ct seq. 



