Plate 7. 



Fig. 



<c 



iC 



CI 



u 



u 



a 



a 



a 



1, a, b, c. Farrea occa claviformis. Gastral clayulae with degenerate teeth; x 450 



u 



u 



u 



2. 



3. 



5. 



11. 



« 



a 



it 



it 



a 



C( 



Dermal pentact with elavulae ; x 250. 

 Gastral clavula; rare form; x 450. 



4. Farrea mexicana. Gastral anchorate clavula; x 450, 



a 



a 



a 



« 



c< 



x450. 



6. Farrea occa claviformis. Gastral pentact with elavulae ; x 250. 



7. Farrea m,exicana. From a photograph ; \, 



8. " " Pentact with umbellate elavulae ; x 250. 



9. Eurete erectum tubuliferum. 



Part of surface view of sponge taken from the side. 

 Axis of entire sponge about vertical. A com- 

 pletely bifurcated (tubular) lateral branch lies 

 to the right, showing a tubular ridge, which 

 marks the line along which the lips of the 

 earlier, cup-like branch fused. A similar 

 tubular ridge lies at right angles to the just- 

 mentioned line of fusion, extending from the 

 tubular branch on to axis of sponge. From a 



photograph ; 



i 



10. Farrea mexicana. Gastral anchorate clavula ; x 450. 



<c 



u 



(( 



u 



a 



; from above ; x 450. 



12. Eurete erectum tubuliferum. From a photograph. Upper end of sponge, from 



above ; \. 







