208 PLATE LXXIV. 



retentive spicula from the dermal membrane. X 530 



linear. 



Fig. 13. A dentato -palmate, inequi-anchorate spicu- 



lum from the dermal membrane. X 530 linear. 



HALICHONDRIA AMBIGUA, Bowerbank. 



Fig. 14 Represents the type-specimen in the cabinet 

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



Fig. 15. One of the acerate skeleton spicula. 

 X 123 linear. 



HYMENIACIDON TEGETECULA, Bowerlank. 



Fig. 16. - -Represents the type-specimen in the 

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



Fig. 17. One of the skeleton spicula. X 250 

 linear. 



HALICHONDRIA PALCULA, Bowerbank. 

 Plate LXXIV. 



Sponge massive, sessile ; surface uneven, minutely 

 spinous and reticulated. Oscula simple, dispersed. 

 Pores inconspicuous ; dermal membrane pellucid, fur- 

 nished with a stout, irregular, polyspiculous net- 

 work : pores dispersed amidst the areas. Skeleton. 

 Rete polyspiculous, very irregular and diffused ; spicula 

 fusiformi-acuate, slender and long. Interstitial mem- 

 branes. Tension spicula same as those of the skeleton, 

 but smaller, few in number. Retentive spicula, 

 trenchant contort bihamate, stout and large, very few 

 in number. Gemmules membranous, aspiculous. 



Colour. In the dried state, cream white. 



Habitat. Shetland ; Rev. A. M. Norman. 



Examined. In the dried state. 



The general appearance of this sponge is much like 



