PLATE XCVI. 



PAGE 



Hexactinella ventilahrum, Carter, . . 331 



Fig. 1. Lateral view of a dry specimen, from a photograph ; natm-al size. 



Fig. 2. Superior view, from a photograph ; x 0"5. 



Fig. 3. Vertical section of the exterior part of the skeleton with the loose spicules 

 in their natural position ; x 50. 



Fig. 4. Discohexaster with short principal and S-shaped terminal rays ; x 300 



Fig. 5. Discohexaster with long principal rays ; x 300. 



Fig. 6. Eough oxydiact corresponding to an uncinatum ; x 300. 



Fig. 7. Exterior part of a dermal scopula ; x 300. 



Fig. 8. Oxyhexaster with long straight terminal rays ; x 300. 



Fig. 9. Part of a gastral scopula ; x 300. 



For " Tretodictyum ci/athus" F. E. Scliulze, on the Plate, read " Hexactinella 

 ventilahrum," Carter. 



1 



