326 H - JAMES-CLARK ON THE AFFINITIES OF SPONGES. 



The mouth is the only organ which has not been actually observed, although its posi- 

 tion has been inferred, not only from the otherwise similar structure of the monad of this 

 creature to that of Codosiga (§ 6), but because currents of floating particles are constantly 

 whirled in by the tlagella and made to impinge upon the area within the collar. In addi- 

 tion to this it may be added that more or less numerous coarse and fine particles (fig. 44, d) 

 are always present, and scattered irregularly about the interior of the monads, apparently 

 under various degrees of digestive decomposition. 



The contractile vesicles (cv) are two in number, and lie near each other, at or about the 

 middle of the body. When fully expanded they are from one fifth to one fourth the diame- 

 ter of the monad, and have a perfectly globular shape. In appearance, and manner and rate 

 of systole and diastole they resemble those of Codosiga so closely that the former might be 

 substituted for the latter with scarcely a chance for a detection of the change. As the rate 

 of systole of each vesicle, which is once in half a minute, was observed directly through the 

 undisturbed layers of the colony, and moreover at the edge of the ostioles, there need be 

 no hesitation in accepting the record as that of the normal measure of pulsation. 



§ 11. Anthophysa Mulleri, Bory. 

 (Plate X., figs. 47-63.) 



A description of this infusorian — but without illustrations — has already been sent for 

 publication to the "American Journal of Science," and will appear in its September number. 

 In order to carry out the object of this memoir to its fullest extent, I propose here to make 

 quite large extracts from this paper, and also to add a number of figures, both for the better 

 understanding of the character of the animal, and for the sake of comparison with others, 

 which are illustrated in the accompanying plates. 



The mononematous Flagellata which are described in the foregoing pages (§§ 1-10), are 

 connected with the heteronematous forms through two diverse lines ; or rather they are 

 closely allied to two different types of diversiflagellate infusoria, of which Anthophysa is an 

 example of one type, and Anisonerna (§ 13) a representative of the other; both of the flagella 

 of the former being proboscidiform, and of the latter, one being gubernaculiform and the 

 other proboscidiform. The intimate alliance of Anthophysa with Monas may be best ex- 

 pressed by saying that the former is a Monas modified by the addition of a comparatively 

 minute cilium which is affixed to the head near the flagellum. 



Anthophysa Mulleri, Bory (Epistylis? vegetans, Ehr.) is quite common among fresh-water 

 plants, such as Myriophylhm, CeratophyUum, and TJtricularia, and adheres to their filiform 

 leaves like an irregular, floccose, brownish deposit. 



" Under a low magnifying power this floccose matter appears to consist of clusters of very 

 jagged, irregularly branching and contorted, semi-transparent, intertwined stems and project- 

 ing, tapering, and flexible twigs (pd). Each of the tips of the latter sustains a single, more 

 or less globose mass of spindle-shaped bodies (md), which radiate from a common centre of 

 attachment, and are kept in a constant agitation by the spasmodic jerks of a long, stout, 

 usually rigid, arcuate filament (fl), with which the free end of each one is endowed. The 

 whole bristling mass revolves alternately from right to left, and from left to right ; whirling 

 upon its slender pivot with such a degree of freedom that one might almost suspect that it 

 merely rested upon it, and had no truer adhesion to it than the juggler's top to the end of 



