282 PLATE LXXXIV. 



spicula acuate, large and long, disposed in slightly 

 radiating fasciculi. Oscula and pores inconspicuous. 

 Dermal membrane pellucid, abundantly spiculous ; 

 spicula acerate, long and very slender, frequently 

 flexuous ; irregularly disposed. Skeleton. Compact ; 

 spicula acuate, large, long, and frequently flexuous, 

 rarely acerate or cylindrical. Internal defensive spicula 

 entirely spined, attenuato-acuate, short and stout ; 

 sjDines acutely conical. 



Colour. — In the dried state, light fa'n^n yellow. 



Habitat. — Shetland, Rev. A. M. Norman. 



Examined. — In the dried state. 



I am indebted to my friend the Rev. A. M. Norman 

 for the loan of this interesting specimen. It was 

 dredged by him at Shetland in 1863. It is eight and 

 three quarter inches in height and its greatest lateral 

 expansion is about four inches. The whole of the 

 branches are in nearly the same plane and its mode of 

 growth is remarkable, the primary l^ranches being 

 projected upwards, dividing dichotomously or trichoto- 

 mously, while the secondary ones are projected at right 

 angles from the primary ones ; a peculiarity of growth 

 that may well be accepted as a sjoecific character. The 

 branches are all nearly uniformly cylindrical. When 

 relaxed in water the portion so treated exhibited 

 scarcely any traces of the external defensive spicula, and 

 in its living condition the surface would jDrobably 

 appear quite smooth. In the dried state the surface is 

 distinctly but minutely hispid. When a portion of 

 the surface mounted in Canada balsam is viewed as a 

 transparent object with a power of about 100 linear, it 

 presents a remarkable appearance. It is deeply and 

 rather irregularly pitted, the boundaries of the pits being 

 formed by lines of fasciculi of large external defensive 

 spicula, each bundle consisting of from two to five or six 

 slightly diverging spicula, the lines of fasciculi being 

 connected by elevated ridges of dermal tissue ; this 

 deeply pitted character exhibiting the mode of disposi- 

 tion of the defensive fasciculi in a very striking manner, 



