206 Prof. H. James-Clark on the Spongise ciliatce 



with Rhizopods, and I will therefore only state here my firm 

 conviction that the true ciliated SjiongicR are not B,luzo]ioda in 

 any sense whatever, nor even closely related to them, but are 

 genuine, o^QWi^ovaA flagellate. Protozoa^ ^xA are most intimately 

 allied to such genera as Monas (§§1, 2), Bicosoeca (§§3, 4), 

 Codonmca (§5), Codosiga (§6), and Saljjmgoeca (§§7, 8, 9). 

 What are the special relationships of the numerous genera of 

 Sponges I am not prepared to say ; yet, in regard to Leucoso- 

 lenia hotryoides^ there can be no doubt that it is very closely 

 allied to Codosiga and Saljringoeca ; but to which one more than 

 to the other would be difficult to determine. Codosiga (§ 6) 

 is a compound form like Leucosolenia, and its individuals are 

 united by a common branching support, which has been shown, 

 by the changes which it passed through during fissigemmation, 

 to be as fully alive as the glairy, spicule-secreting cytoblastema 

 of the Sponge. SaJpingoeca (§§ 7, 8, 9), on the other hand, is 

 a single monad, but excretes around it an envelope, or calyx ^ 

 into which the body is smiken in the same way that the mo- 

 nads (fig. 41,?n(:Z) of the Sponge are imbedded in the surface 

 of their common dormitory. Inasmuch, however, as the calyx 

 is probably an excretion rather than a secretion, and appears as 

 inanimate as that of Cothiirnia^ Vaginicola, and other Vorti- 

 cellidte, it is more comparable to the spictila {sp) than to the 

 cytoblastema of Sponges. If one may draw an inference from 

 the above considerations, it does not seem at all improbable 

 that hereafter we shall find that the monads of the different 

 genera of Sponges resemble the various genera of single and 

 branching Flagellata ; and then we shall be able to divide the 

 former into such family groups as Monadoid^, Bicosoecoidge, 

 Codosigoidte, Anthophysoidas, &c. &c. 



Leucosolenia hotryoides^ Bowerbank, occm-s on om- sea-shore 

 among the groups of Dynamena, Sertularia, &c., and may be 

 readily recognized by its ivory-white colour. The colony 

 is an elongate mass, seldom exceeds an inch or an inch 

 and a half in length, and resembles an irregular group 

 of slender contorted spines or forked horns (fig. 40) , which 

 vary in thickness from one-thirtieth to one-sixteenth of an 

 inch in diameter. At the tip of each horn is an apertm-e, the 

 so-called excurrent orifice, large enough to be seen by the un- 

 assisted eye. The whole mass is so transparent that not only 

 the currents in the interior, but even the vibrating flagella and 

 the pulsation of the contractile vesicles, may be seen with a 

 strong light. The exterior consists of an excessively hyaline, 

 cytoblastematous layer, with scarcely, if any, trace of organiza- 

 tion of a cell-like character in it. Within this layer, or im- 

 mediately beneath it, but certainly not in the monadigerous 



