98 Dr. A. C. Stokes oti some 



EXPLANATION OF PLATE U. 

 Fig. 1. Perichxta ceylonica, Olitellum ami neighbouring- segments : a 



and b, openings of glands lettered a and b in tig. 2. 

 Fig, 2. Prostate glands of same : «, coiled tubular gland j 6, multilobate 



gland. 

 Fig. 3. Genital seta of same. 

 Fig. 3 a. Distal extremity of genital seta. 

 Fig. 4. Diagrammatic transverse section of segment 9 of Moniliyastcr 



Banvelli. ce, alimentary caual ; D, dorsal blood-vessel ; g, veu- 



ti'al blood-vessel; n, nerve-cord; T, testis; I'.f/., v as deferens ; 



2), prostate; v.s., lateral blood-vessel connecting dorsal and ventral 



blood-vessels; s, ventral pair of setge ; s', dorsal pair of seta3. 

 Fig. 5. C.p., copulatory pouch of ssmie ; n, nerve-cord ; s, ventral pair of 



sette ; s', dorsal pair of sette. 

 Fig. 6. Portion of vas deferens of same (y.d. in tig. 4), highly magnitied. 

 Fig. 7. Copulatory pouch of an example of Ferich<eta jpost/mma : three 



pouches in one segment (no. 6). 



XI. — Some new Infusoria from American Fresh Waters. — 

 No. 2. Bj Dr. Alfred C. Stokes. 



[Plate I.] 

 Heteromita variabilisy sp. nov. (PI. I. fig. 1.) 



Body soft, tlexible, and very changeable in shape, sub- 

 spherical, ovate, elongate, subcjlindrical, frequently with both 

 extremities curved towards the ventral aspect, and often with 

 the anterior border slightly and obliquely emarginate ; endo- 

 plasm granular ; tlagella very unequal in length, the trailing 

 appendage twice as Jong as the contracted body, the vibratile 

 one third or one fourtli ot the length of the body ; contractile 

 vesicle single, spherical, located near the centre of the ventral 

 sm'face ; nucleus single, subspherical, near the posterior ex- 

 tremity. Length of body ^ifo to ttW inch. 



Hab. The apparently empty body of a dead Ganthocamjptus 

 miniUuSj Mliller. 



Fig. 1 shows some of the changes in form assumed by this 

 remarkably metabolic creature, of which the posterior extre- 

 mity is especially solt and changeable in shape. The infu- 

 sorian differs from all other members of its genus in the 

 proportionate length of the tlagella, the vibratile appendage 

 being shorter than that of any previously recorded species. 

 The animalcules were observed crowding the empty body of 

 a dead Canthocamptus. 



Paramonas alata, sp. nov. (PI. I. fig. 2. Diagram.) 



Body ovate, persistent in form, about twice as long as 

 broad, widest and rounded posteriorly; traversed longitudinally 



