Plate 7. 



Fig. 1, a, h, c. Farrca occa claviformis. Gasti'al clavulae with degenerate teeth; x 450. 



2. " " " Dermal pentaet with clavulae ; x 250. 



3. " " " Gastral claviila; rare form ; x 450. 



4. Farrea mexlcana. Gastral auchorate clavula ; x 450. 



5. " " " " " X 450. 



6. Fai-riM ncca dainformis. Gastral pentact with clavulae ; x 250. 



7. Fnrren mexicdiia. From a photograph ; }. 



8. " " I'eiitaet witli umbellate clavulae ; x 250. 



9. Eurete erectiim tubuUfenun. I'art 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, cnp-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 ; \. 



10. Farren niexicana. Gastral anchorate clavula ; x 450. 



11. " " " " " ; from above ; x 450. 



12. Eurete crectum tuhulifrnivi. From a photograph. Upper end of sponge, from 



above ; }. 



