H. JAMES-CLARK ON THE AFFINITIES OF SPONGES. 339 



or invested food. — e, furrow in fissigemmation ; e 1 , anterior end of e; e", prolongation of e, e 1 . — /, broad sulcus, (in 



Heteromastix). • fl, flagellum ; fl\ minor flagellum ; fl 2 , gubernaclum. — fr, frontal area. — i, neck, or anterior half 



of body. lp, lip. — m, mouth ; m\ jaws. — md, monads of the Sponge, etc. — n, reproductive organ. — o, ostioles. 



W, pedicel; pd 1 , top oipd ; pd 2 , forks of pd. — r, retractor muscle ; r\ furrow in which r is imbedded, and attached. 



S; eve-spot. — si, si, 1 saltatory cilia. — sp, triradiate spicula, sp 1 , aciculate spicula. — t, margin of the inrolled side 



of Anisonema ; t 1 , the deep furrow or covered way behind t. — v, broader valve of Dysteria ; v\ the narrower valve. 



Explanation of Plate IX. 



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 (lp) next the observer, and the contractile vesicle (cv) in profile. 950 diam. Fig. 3, an 

 attached form seen from the broad side. 1200 diam. Fig. 4, a free monad in the act of swallowing a large morsel 

 of food. 950 diam. 



Figs. 5, 5 a , 5 b , 6. Monas neglecia, n. sp. Fig. 5, broad-side view of a pedicellated monad. 950 diam. Fig. 5% a 

 posterior view showing the axial attachment of the pedicel (pd 1 ) and the contractile vesicle (cv) in profile, and the 

 flagellum ( fl) in the distance. 950 diam. Fig. 5 b , a free monad in the act of swimming. 950 diam. Fig. G, an at- 

 tached form, contorted in the act of swallowing a large morsel of food. 950 diam. 



Figs. 7-27. Codosiga pulcherrimus, n. sp. Fig. 7, a colony of eight monads, drawn within an hour after the fissigem- 

 mation 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, with three contractile vesicles (cv). The dotted lines indicate the degree 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 (p. 316). Fig. 23, a free monad in the act of swimming; the vibrating 

 flagellum (/) 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 (b) contracted into a cone, and the flagellum (fl) vibrating 

 rapidly. 950 diam. Fig. 24% a very large pedicellated form, just before fissigemmation begins ; the body partially 

 contracted, and the collar (b) vibrating. The peculiar sigmoid curve of the. flagellum (fl) is well shown here. 950 

 diam. Fi<*s. 25, 26, 27, showing the different degrees of contraction of the membranous collar (b) of the same in- 

 dividual. In fig. 25, the. flagellum (fl) is vibrating rapidly, just at the moment when the collar (b) has returned to 

 its usual form and attitude. 750 diam. 



Figs. 28-32". Salping&ca marinus, n. sp. Figs. 28, 29, 30, the same individual 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 1 ). 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 1 ). 1900 diam. Fig. 32 a , an empty calyx closed. 1900 diam. 



Figs. 33, 33°, 33% 33 c . Bicosaca lacustris, n. sp. Fig. 33, an adult, with the lip (lp) nearest the eye, the flagel- 

 lum (fl) in the background, and the longitudinal furrow seen through the body. The flagellum (fl) is uncoiling just 

 as the body emerges from the bottom of the calyx (c). 950 diam. Fig. 33% a young animal in profile, showing the 

 peculiar attitude and curve of the flagellum (fl), the narrow aperture (c 1 ) of the calyx (c), and the unilateral attach- 

 ment of the retractor muscle (r). The pedicel (pd) is just beginning to develop. 950 diam. Fig. 33% a young form 

 partially emerged from the bottom of the calyx (c), the latter contracted at the mouth (c 1 ) and the flagellum (fl) 

 forcing its way through, as is usual, in a loop. 950 diam. Fig. 33 c , the same as fig. 33% retracted to the bottom of the 

 calyx (c) and the aperture (c 1 ) of the latter nearly closed. 950 diam. 



Figs. 34, 35. Bicosmca gracilipes, n. sp. Fig. 34, the longitudinal furrow (r 1 ) and the flagellum (fl) next the 

 eye; the lip (lp) in the background. 1900 diam. Fig. 35, the body retracted to the bottom of the calyx (c), and 

 the flagellum beginning to uncoil. 950 diam. 



Fig. 36. Godonceca costata, n. sp. The body seated in the bottom of the pedicellated calyx (c). 950 diam. 

 Figs. 37, 37% 37% 37% 37% Salpingceca amphoridium, n. sp. All magnified 950 diameters. Fig. 37, an individ- 

 ual suspended freely in its calyx (c, c 1 ). The dotted lines indicate the attitude which the collar (b) assumed for a 

 while during the observation upon this specimen. A particle of foecal matter has just left the anus (a). Fig. 37% 

 the lower part of the calyx filled by the body, the upper part (c 1 ) free from the neck (i) of the animal, and the 

 membranous collar unusually narrowed. Fig. 37% the calyx mostly filled by the body, the head (*) bent to one side, 

 and the flagellum (fl) in the act of expelling a particle of undesirable matter. Fig. 37 c , an empty calyx, slightly 

 contracted in dimensions. Fig. 37% the body contracted and filling the calyx, and the membranous collar (J) partially 

 retracted. 



