262 Prof. H. James-Clark on the Spongise ciliatje 



^' minor flagelliim ; fJ^, gubernaclum : fr, frontal area : i, neck or anterior 

 half of body : Ip, lip : m, moutli ; w\ jaws : mcl, monads of the Sponge, &c. : 

 n, reproductive organ : o, ostioles : pd, pedicel ; pr/', top oi2)d; jid-, forks 

 oipd : r, retractor muscle ; r\ furrow in which r is imbedded and attached : 

 s, eye-spot : si, sP-, saltatory cilia : sp, triradiate spicula ; sp^, acicidate 

 spicula : t, margin of the inrolled side of A?usone)na ; V-, the deep furrow 

 or covered way behind t : v, broader valve of Dijsteria ; v^, the nari'ower 

 valve. 



Figs. 1-4. Monas termo, Ehr.?. Fig. 1, a group of free monads, 500 diam. 

 Fig. 2, a free monad seen from the narrower side, with the lip 

 (Ip) next the obsei'ver, and the contractile vesicle (cv) in profile, 

 950 diam. Fig. 3, an attached form seen from the broad side, 

 1200 diam. Kg. 4, a free monad in the act of swallowing a 

 large morsel of food, 950 diam. 



Figs. 5, 5*, 5^, 6. Monas neglecta, n. sp. Fig. 5, broad-side view of a pedi- 

 cellated monad, 950 diam. Fig. 5^, a posterior view, showing 

 the axial attachment of the pedicel {pd^) and the contractile 

 vesicle (cv) in profile, and the flagellum (Jl) in the distance, 

 950 diam. Fig. 5'', a free monad in the act of swimming, 950 

 diam. Fig. 6, an attached form, contorted in the act of swal- 

 lowing a large morsel of food, 950 diam. 



Figs. 7-27. Codosiga 2Mlcherrima, n. sp. Fig. 7, a colony of eight mo- 

 nads, drawn within an hour after the fissigemmation of three of 

 its members, 150 diam. Fig. 8, a group of five, in a bird's-eye 

 view, 500 diam. Fig. 9, a single monad Tvath three contractUe 

 vesicles (cr), the dotted lines indicate the degi-ee of the lateral 

 vibrative expansion of the membranous collar (b), 950 diam. 

 Fig. 10, the same as fig. 9, preparing to undergo fissigemmation ; 

 the body is contracted and widened, and the collar (b) broadened. 

 Figs. 11-22, to illustrate the process of fissigemmation, 750 

 diam. ; for particulars see the text (pp. 196-199). Fig. 23, a free 

 monad in the act of swimming, the vibrating flagellum (fl) 

 acting as a propulsory agent and following in the rear, 950 diam. 

 Fig. 24, a single pedicellated monad from old, stale water, the 

 membranous collar (6) contracted into a cone, and the flagellum 

 (Jl) -vibrating rapidly, 950 diam. Fig. 24% a very large pedi- 

 cellated form, just hetore fissigem77iation begins, the body par- 

 tially contracted, and the collar (b) vibrating ; the pecvdiar sig- 

 moid ciu've of the flagellum (Jl) is well shown here, 950 diam., 

 — figs. 25, 26, 27, showing the diff'erent degrees of contraction 

 of the membranous coUar (b) of the same individual : in fig. 25 

 the fiagellu7n (fi) is vibrating rapidly, just at the moment when 

 the collar (b) has retm-ned to its usual form and attitude, 750 

 diam. 



Figs. 28-32". Salpitigoeca maritia, n. sp. Figs. 28, 29, 30, _ the same in- 

 dividual in different states of expansion, 1900 diam. Fig. 31, 

 the body completely filling the calyx, so that the latter is 

 scarcely 'distinguishable except at its mouth (c^), 1900 diam. 

 Fig, 32, showing the calyx as a distinct envelope considerably 

 separated from the body at the bottom (c) and at the aperture 

 (c-i), 1900 diam. Fig. '32", an empty calyx closed, 1900 diam. 



Figs. 33, 33", 33"', 33*^. Bicosoeca lacustris, n. sp. Fig. 33, an adidt with 

 the lip (I}}) nearest the eye, the flagellum (fl) in the back- 

 ground, and the longitudinal fun-ow seen through the body. 

 The flagellum (fi) is imcoiling just as the body emerges from 

 the bottom of the calyx (c), 950 diam. Fig, 33", a yoimg 



