250 Mr. H. J. Carter on Difflugia pyriformis. 



(albuminous?) substance. Animal consisting of diaphane and 

 sarcode, tte former disposed in a transparent layer around the 

 latter, xnd sending off processes of attachment from its posterior 

 third^to the inner surface of the test ; sarcode more or less 

 clquded by the presence of chlorophyll-cells, which impart a 

 green colour to the body, by the " moleculse," the " granules," 

 /and portions of food in process of digestion. Granules abun- 

 dant, minute, colourless. Nucleus situated in the posterior 

 end of the body, fixed, and consisting of a transparent spherical 

 cell bearing on one part of its inner surface the nucleolus in 

 the form of a circular, colourless, opake, discoid body much 

 less in diameter than the nuclear cell. Contracting vesicles or 

 " vesiculse " not seen, but probably in plurality, and situated 

 round the border of the posterior end, as in D. tricuspis, Cart. 



Hah. Fresh water, in stagnant pools, with decaying leaves 

 and vegetable matter. Active in the spring (April), passive and 

 more or less retracted within the test in the autumn (August). 

 Locomotion and capture of food performed by digital prolonga- 

 tions of the body slowly projected through the aperture of the 

 test, and into which the chlorophyll-cells do not enter. 



Size. Length -^ih, greatest breadth -rs-otb, and width of 

 aperture -j^th of an inch. Thus the test is a little longer than 

 twice its breadth. In ujMvards of 200 specimens the measure- 

 ments varied very little from those given. 



Loc. England, south coast of Devonshire. 



Observations. — I learn from MM. Claparede and Lachmann 

 (Etudes sur les Infusoires et Ehizopodes, p. 448, for a copy of 

 which work, received since my return from India, I now beg to 

 acknowledge myself under great obligation to the authors — the 

 latter, alas ! removed by death too soon for the interests of 

 science) that there is a Difflugia pyriformis, Perty (Zur Kennt- 

 niss, &c., p. 187, pi. 9. ob. Abth. f. 9) ; and I see a figure of 

 D. pyriformis in pi. 21. f. 17 of Pritchard's 'History of the 

 Infusoria' (ed. 1861) without further mention, but so much like 

 the one which I have above described, that, on the evidence 

 altogether, I do not hesitate to call the Devonshire specimens 

 D. pyriformis, Perty. Also, among upwards of 200 specimens 

 of D. pyriformis, I have only found five with that diverticulum 

 at the posterior end which led Ehrenberg to call it D. acuminata, 

 but in other respects so like, in the green body and sandy com- 

 position of the test, that I cannot help thinking it is only a 

 variety of D. pyriformis. Each of these five, however, were only 

 about — oirth of an inch long, including the diverticulum, while 

 D. acuminata (ap. Pritchard) is set down at y-Q-th of an inch in 

 length. Lastly, among the 200 were also tliree or four sub- 

 globose specimens, like D. proteiformis, Ehr., which are set 



