PLATE L. 



PAGE 



Fig. I. Stylocordyla stijntata, var. glohosa, segment of horizontal section; ect., 



ectosome ; ch., choanosome ; p., pore; i.e., inhalent canal; e.c, 



small exlialeut canal opening into large exhalent canal ; /., fibrous 



wall of large exhalent canal ; x 44, . . xxxii, xliii, xlvi, &c. 



Fig. 1«. Portion of similar section at the junction of ectosome and clioano.some ; y.c, 

 V glandular [1) cells of the ectosome ; f.t., fibrou.s ti.ssue of the ectosome ; i.e., 



inhalent canals; f.c, flagellated chambers; e.o., opening of a flagellated 



chamber into an exhalent canaliculus ; x 284. 

 Fig. 16. Small portion of section through choanosome, showing the flagellated 



chambers. 



Fig. 2. Suberites perfectus, section at right angles to the surface; ect., ectosome; 

 ch., choanosome; p., pores; s.c, subdermal caYvties; f.t., fibrous 

 tissue ; x 66, ....... xxiii 



Fig. 2a. Fibrous tissue, from a spot where the granular bodies {g.) are much more 



developed than usual ; x 284. 

 Fig. 21. Fibrous tissue, from a spot where the granular bodies (g.) are developed to 



about the usual extent ; x 284. 



Fig. 3. Tentorium semisuherites, external view of the entire sponge, showing o, 



the osculum, and p.a., the single, large ^iore-area ; natural 



size, ...... xxxi, xl, xliii 



Fig. 3«. Vertical section through the pore-area; ed., ectosome; ch., choanosome; a., 

 outer layer of ectosome ; b., middle layer of ectosome ; r., inner layer of 

 ectosome; ^j., pores; s.c, vertically elongated subdermal cavities ; p'., narrow 

 canaliculus leading from subdermal cavity into i.e., inhalent canal ; x 44. 



TTie spicules are printed in blue. 



