PLATE XCIII. 



PAGE 



Hexactinella tubulosa, F. E. S., . . . 328 



Fig. 1. A dried specimen, from a photograph ; natural size. 

 Fig. 2. Transverse section of the tube wall without the soft parts ; x 30. 

 Fis- 3. Small uucinatuni ; x 450. 



Fig. 4. Dermal scopula with four strong, barbed, uuknobbed prongs ; x 300. 

 Fig. 5. Gastral scopula with four strong, barbed, unknobbed prongs ; x 300. 

 Fig. 6. Small smooth oxydiact ; x 450. 



Fig. 7. Oxyhexaster with somewhat long principal rays ; x 450. 

 Fig. 8. Simple oxyhexact with rough rays ; x 450. 



The generic name " Tretoclictyum " was printed off on the Plate before the pul^lication 

 of Carter's description of his genus Hexactinella, to which I now refer this species. 



