442 Dr. A. C. Stokes on some 



tioned, but always there. Its movements are very similar to 

 those of T. flavicans. The food-masses also receive the 

 spherical form ; but the rotation of the endoplasm so notice- 

 able in T. fiaoicans is here seldom visible. In colour the 

 infusorian is a deep amber, the tint varying with that of the 

 infusion and, to a certain extent, with age, the young animal- 

 cules being paler than the mature. Reproduction takes place 

 by encystment, with subsequent binary or quadruple fission, 

 the young resembling the undivided forms in all except 

 colour. Conjugation has not been observed. 



Lacrymaria truncata, sp. nov. (PL XV. fig. 10.) 



Body flask-shaped or clavate, flattened, very soft and 

 flexible, four and one half to five times as long as broad, 

 narrowed into a neck-like region anteriorly, the frontal border 

 of which is somewhat dilated and obliquely truncate, the 

 apical groove conspicuous ; the posterior extremity rounded ; 

 entire surface strongly and longitudinally striate ; cuticular 

 cilia long and fine ; oral aperture terminal, followed by a long 

 conical membranous pharynx, visible only after death ; apical 

 o-roove bearing a single row of cilia ; contractile vesicle 

 sino-le, spherical, postero-terminal ; nucleus long, band-shaped, 

 variously curved and twisted, having several laterally-attached 

 nuclei ; anal aperture postero-terminal. Length of body ^^ 

 inch. 



Rah. Standing water, with dead leaves. 



This is the only freshwater member of the genus thus far 

 observed. It is remarkable for the very long and band-like 

 nucleus, and especially for the capacious conical pharyngeal 

 passage, which has hitherto not been recorded as appearing 

 in any of the several marine species. It is here visible only 

 after the animalcule's death, which in this instance was 

 accomplished by the glycerole of tannin, when it becomes 

 conspicuous, and is seen to occupy almost the entire width of 

 the frontal border, thence tapering to an acute termination 

 and extending through about one third of the entire body. 



In most of the species the apical extremity is conical ; 

 here however, it is conspicuously flattened, oblique, and 

 truncate. As the infusorian now referred to is undoubtedly 

 a member of the genus Lacrymaria, a slight change in the 

 generic diagnosis would seem necessary ; and such change 

 would be preferable to the erection of a new generic title for 

 the creature, as might seem desirable on account of the cushion- 

 like apical extremity and the extensively developed pharyn- 

 geal passage. The latter probably brings the genus closer to 



