207 



PLATE LXXIV. 



HALICHONDRIA FALCULA. 



Fig. 1. Represents the type-specimen in the cabinet 

 of the Rev. A. M. Norman. Natural size. 



Fig. 2. A skeleton spiculum. X 250 linear. 



Fig. 3. One of the trenchant, contort, bihamate, 

 retentive spicula. X 250 linear. 



HALICHONDRIA MUTULA, Bowerbank. 



Fig 4. Represents the type-specimen in the cabinet 

 of the Rev. A. M. Norman. Natural zize. 



Fig. 5. A skeleton spiculum. X 123 linear. 



Fig. 6. One of the slender, acuate, tension spicula 

 X 123 linear. 



Fig. 7. A tricurvato-acerate tension spiculum. 

 X 123 linear. 



Fig. 8. One of the minute, dentato-palmate, equi- 

 anchorate, retentive spicula. X 530 linear. 



HALICHONDRIA EXPANSA, Bowerbcmk. 



Fig. 9. Represents the type-specimen from the Isle 

 of Skye. In the cabinet of the Rev. A. M. Norman. 

 Natural size. 



Fig. 10. One of the long, slender, incipiently- 

 spinous, tension spicula of the dermal membrane. 

 X 250 linear. 



Fig. 11. A skeleton spiculum, entirely and in- 

 cipiently spinous. X 250 linear. 



Fig. 12. One of the bi-dentate, iuequi-anchorate 



