88 Journal of the Asiatic Society of Bengal. [January, 1913.] 
Fig. 3.—Skeleton-spicules of Nudospongilla mappa (A. x 120: 
B. x 40). Fig. 3a.—Vertical section of part of skeleton 
from the external surface to the base of the sponge, x 20. 
Fig. 4.—Skeleton-spicules of Nudospongilla aster (A. x 120: B. 
x 40). Fig 4a.—Vertical section of part of external region 
of skeleton, x 20. 
Fig. 5.—Skeleton-spicules of Cortispongilla barroisi (Topsent), 
x 40. 
N.B.—In all the figures of vertical sections of the skeleton 
the upper profile represents the external surface. 
PuaTte IV. 
Vertical Sections of the External Region of the Skeleton 
in Five Genera of Freshwater Sponges: all x 16. 
Fig. 1.—Corvospongilla burmanica bombayensis, Annand. (from 
Idar State, Bombay Presidency). 
Fig. 2.—Potamolepis pechueli, Marsh. (from the Liapulu RB., 
Central Africa). 
Fig. 3.—Pachydictyum globosum, Weltner (schizotype). 
Fig. 4.—Cortispongilla barroisi, (Topsent) (topoty pe). 
Pig. 5.—Veluspa abietina, Schki. (from Lake Baikal). 
PLATE V. 
Dermal Pores, etc., in the Spongillidae. 
Fig. 1.—Spongilla proliferens, Annand.: a dermal pore-cell, x 
ta (fixed in absolute alcohol and stained with haematoxy- 
in 
Fig. 2.—Nudospongilla mappa: photograph of a part of the 
external surface of the type-specimen (dried), x 7; to show 
the circular pore-areas. Fig. 2a.—A single pore-area with 
the supporting skeleton as seen from the external surface 
(fixed with picroformol-acetic solution and stained with 
borax carmine), x 50. Fig. 2b.—Part of the same prepara- 
‘ion, x 200. 
Fig. 3.—Nudospongilla reversa: photograph of a part of the 
external surface of the type-specimen (dried), x 7; to show 
the scattered pore-areas. 
Fig. 4.—Uruguaya amazonica, Weltner : vertical section through 
an osculum, x 40; to show the thickened pneumatic exter- 
te 
nal membrane and the skeleton-spicules lying parallel to 
it. 
Note.—In figure 2b. the nuclei of the pore-cells are not clearly 
differentiated from chance accumulations of granules as 
was the case in the original drawing 
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