GENUS CALLODICTYON. 307 



This species, originally described by Ehrenberg under the title of Monas vivipara, 

 is distinguished more particularly by the presence of the innumerable moving cor- 

 puscles enclosed within the substance of the endoplasm, and which were mistaken by 

 that authority for its living progeny. Stein, who has recently figured it in connec- 

 tion with the same name, has added the fuller details of the flagella, mode of attach- 

 ment, and positions of the endoplast and contractile vesicle here recorded. The 

 author has recently encountered an animalcule closely resembling the present form 

 in hay infusions, it being of the same size and enclosing similar motile corpuscles 

 within the endoplasm ; the endoplast was, however, in these instances, situated to 

 the rear of the contractile vesicle. The ingestion of food was observed on numerous 

 occasions, a film of sarcode being thrown out at such times and enveloping the 

 captured particle. This film was projected indifferently from various parts of the 

 anterior border, and sometimes simultaneously from two separate portions of the 

 periphery. In no instance could the linear pigment-band or so-called oral ledge or 

 furrow, as indicated in Stein's drawings, be detected, and which circumstance, 

 together with the variation in the position of the endoplast, favours the opinion 

 that we have in this last-named instance a closely allied but specifically distinct 

 variety. 



Fam. XIV. TRIMASTIGID-ffi, S. K. 



Animalcules naked, free-swimming or temporarily adherent ; flagella 

 three in number, equal or subequal, inserted close to one another; no 

 distinct oral aperture. 



Genus I. CALLODICTYON, Carter. 



Animalcules naked, entirely free-swimming, more or less ovate but 

 plastic and somewhat variable in form ; endoplasm highly vacuolar or 

 cancellate, presenting a reticulate appearance ; flagella three in number, 

 similar in size and character, originating close to each other near the centre 

 of the anterior border ; no distinct oral aperture, all parts of the periphery 

 being equally capable of incepting food-substances. 



Callodictyon triciliatum, Carter. Pl. XIX. Figs. 16-19. 



Body subpyriform, straight or slightly curved, from one and a half to 

 twice as long as broad, widest anteriorly, tapering towards the posterior 

 end, which is sometimes sharply and sometimes obtusely pointed and 

 bifid at its extremity ; flagella slender, equal in length to about one-half 

 that of the body, inserted within a small depression in the centre of the 

 anterior border ; endoplasm transparent, divided up by innumerable equal- 

 sized spherical vacuoles so as to present a reticulate or cellular aspect ; 

 endoplast spherical, anteriorly situated ; no distinct contractile vacuole. 

 Length 1-770". Hab. — Fresh water with Euglencs : Bombay (H. J. C). 



This singular animalcule is figured and described under the above title in 

 Mr. Carter's account of the " Fresh- and Salt-water Rhizopoda of England and 

 India," in the 'Annals of Natural History' for April 1865. Its plastic nature, 

 and capacity of incepting food at any portion of its periphery, as in the case of 

 Amoeba, has induced this authority to refer the type to the section of the Rhizopoda, 

 but it is very evident that its rightful position is among that newly instituted Panto- 

 stomatous division of the Infusoria Flagellata as delimited in this treatise. The 

 voracity of this type, as evidenced by its discoverer, is very remarkable, organisms 



X 2 



