PLATE XL. 
Figs. 1, 2. Anthastra parvispicula, 
Figure 1. A poral cFone in transverse section, to show the position of two 
supposed sesthocytes ; x 73. The sesthocytes are indicated by two 
dashes on the right of the figure, slanting downwards towards a recess 
in the chone. 
,, 2. Part of the preceding, more highly magnified, to show the supposed 
sesthocytes, which present a somewhat darker tint than the other 
cellular constituents of the tissue ; x 292. 
Figs. 3, 4. Cydonium glariosus, 
„ 3. Transverse section through the cortex and adjacent choanosome, showing 
embedded sand grains and pencils of small oxeas ; x 32. 
,, 4. Tangential slice from the surface of the sponge, showing the pores, and 
the asters below the epithelium ; x 180. 
Fig. 5. CranieUa simillima, 
„ 5. Longitudinal median section through the solid planula; x 73. The 
columnar cells of the outer layer are shown more highly magnified 
above the chief figure ; x 430. 
Fig. 6. Characella aspera, 
„ 6. The sponge ; nat. size. 
Fig. 7. Placospongia carinata, 
„ 7. Transverse section ; x 10. 
Fig. 8. Astrella vosmaeri, . 
„ 8. Transverse section through the cortex, showing the characters of the 
chones; x 51. 
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