52 B. GEASSI AND A. SANDIAS. 



The surface of tlie body is covered with flagella about 18 /z 

 in length ; if it is viewed lengthways, the flagella are seen to 

 be arranged in oblique lines which run in opposite directions 

 on the two faces, as an alteration of the fine adjustment shows. 

 Appropriate observation suggests that they are disposed uni- 

 seriately in spiral lines, but their mode of origin at the anterior 

 extremity and the number of turns made by each line appear 

 impossible to determine, on account of the close juxtaposition 

 of these turns over the anterior papilla. The spirals may or 

 may not extend to the posterior extremity, and the lines of 

 origin of the flagella appear subelevated throughout. 



The ectoplasm difi'ers from the endoplasm only in its greater 

 density and freedom from food-granules. 



In connection with the anterior extremity is a tubular 

 organ, as in Trichonympha. 



All the larger examples possess five or more rodlets, which 

 may be somewhat bent at the level of the nucleus, as if to 

 embrace it; they converge in front of it and lie in close proxi- 

 mity to each other, being disposed according to a slightly 

 curved surface, and thus giving the animal a bilateral 

 symmetry. 



VII. 



HoLOMASTiGOTES ELONGATUM, gcn. et sp., Grassi. (PI, 20, 

 figs. 21—24.) 'Atti Ace. Lincei' (5), i, p. 36. 



Reaching a length of 60 n, and a corresponding width of 

 20 to 24 in. Oval, very elongate, with the posterior extremity 

 usually the more attenuated. The anterior papilla wanting ; 

 the flagella arranged as in the preceding species in spiral 

 lines, easily seen, during contraction of the body, to start from 

 the anterior pole. During elongation other spiral lines, which 

 do not extend to the anterior extremity, are seen to be inter- 

 calated between those bearing the flagella. 



Ectoplasm as in the preceding species : the endoplasm con- 

 stantly contains very numerous, scarcely refringent granules, 

 which might be taken at first sight for nuclei; they disappear 

 with acetic acid, and do not stain. Similar granules may 



