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



Figs. 38, 39. Salpingoeca gracilis, n. sp. 950 Jiara. Fig. 38, the body retracted within the calyx (c, c 1 ). Fig. 

 39, the same as fig. 38, partially protruded from the calyx. 



Figs. 40-44. Leucosolenia ( Grantia) botryoides, Bowrbk. Fig. 40, a colony of sponge ; natural size. Fig. 41, 

 view of a profile section of the monadigerous layer ; the monads (md) closely packed together, side by side, with 

 the membranous collar (b) and the flagellum ( ft) projecting into the general cavity of the colony. 950 diarn. Figs 

 42, 43, 44, isolated monads with the membranous collar (It) in various attitudes. 950 diam. See also fig. 64. 



Figs. 45, 46. Astasia tricophora, Clap. Fig. 45, a dorsal view, the mouth seen through the head, and the guber 

 naclum (fl 2 ) in the background. 500 diam. Fig. 46, the body in an amoeboid, contorted state. 500 diam. 



Explanation of Plate X. 



Figs. 47-63. Anthophysa Mulleri, Bory. Fig. 47, a colony of adults attached to a single tubular branchlet or 

 pedicel (pd). One of the monads is in the act of passing a morsel into its mouth (m). 950 diam. Fig. 48, a pair 

 of adults, seen in profile. 950 diam. Fig. 49, a pair of young monads ; one in profile and the other presenting its 

 narrow side. 950 diam. Figs. 50 and 51, different attitudes of the same monad as the one in profile in fig. 49, during 

 the introception of food. 950 diam. Figs. 52-61, to illustrate the process of fissigemmation. 950 diam. Fig. 62, a 

 piece of a tubular branchlet like fig. 47, (pd). 1900 diam. Fig. 63, a piece of a flat branch from an old part of the 

 colony. 950 diam. 



Fig. 64. Leucosolenia botryoides, Bowrbk. A portion of the monadigerous layer (md) seen through the spiculifer- 

 ous stratum, with the spicula next the eye. 500 diam. 



Figs. 65-69. Anisonema concava, n. sp. All magnified 500 diameters. Fig. 65, a dorsal view, the inrolled 

 margin (t) seen through the body. Fig. 66, a ventral view of fig. 65, the base of the gubernaclum (fl 2 ) covered 

 by the inrolled edge (t). Fig. 67, a profile view of the right side of the body, showing its concavo-convex character. 

 Fig. 68, an end view, to show the lateral extent of the covered way from which the gubernaclum (fl 2 ) and the an- 

 terior flagellum (fl) spring. Fig. 69, a ventral view of an animal which possesses two extra flagella (fl s ). It is 

 probably in the incipient stage of fissigemmation. 



Figs. 70-74. Heteromastix proteiformis,Jas.-C\k. All the figures are magnified 500 diameters. Fig. 70, profile 

 view of the right side of a fully extended animal, the gubernaclum ( fl 1 ) trailing beneath. Fig. 71, the same as fig. 

 70, in a partially contracted state. Fig. 72, an individual seen directly from below, with its anterior end strongly 

 retracted and broadened. Fig. 73, an animal partially contracted and propped up on its tail by its flagella (fl,fl~), 

 and exposing its ventral, ciliated furrow (/) to full view. Fig. 74, an end view of the head, with the group of cilia 

 (cl) on the lower side. 



Figs. 75, 76. Pleuronema instabilis, Jas.-Clk. Fig. 75, a dorsal (ventral, homologically speaking,) view. 1000 

 diam. Fig. 76. an end view of the head ; the contractile vesicle (cv) in the foreground, and the, flagellum (fl) in 

 the di>tance. A part of the ventral side is destitute of cilia. 500 diam. 



Figs. 77, 78. Dysteria prorcefrons, Jas.-Clk. Fig. 77, a view of the dorsal (homologically the ventral,) side, the 



broader valve (v) next the eye, and the narrower, three-beaked valve (v\ bk) in the extreme distance. 600 diam. 



Fig. 78, a fore-shortened view of the body as it appears when turned up on its right edge ; the head next the 



observer, and the pivot (fl 2 ) in the distance. 600 diam. 



Published September, 1867. 



