92 A MONOGRAPH OF THE 



4. Tethea Ltn curium, Johnston. 



Alctonium LTNCURnJM, lAnnaus. 



Sponge. Massive, globular, sessile. Surface smooth and 

 even. Oscula and pores inconspicuous. Dermis thick 

 and coriaceous ; furnished abundantly with large sub- 

 sphero-stellate spicula with acutely conical radii, and 

 near the external surface with numerous minute 

 attenuato-stellate spicula. Skeleton. Spicula fusiformi- 

 acuate, large and long, fasciculated into long stout 

 bundles, which expand greatly at their distal corym- 

 bose terminations. Interstitial membranes furnished 

 abundantly with long, slender, fusiformi-acerate tension 

 spicula, dispersed in lines radiating from the centre of 

 the sponge towards the inner surface of the dermis, 

 and with numerous minute attenuato-stellate spicula. 

 Gemmules. External, pullulating from near the base 

 of the sponge ; spicula, same forms as those of the 

 parent. 



Colour. — Alive, dull orange, to bright chrome yellow. 



Habitat. — Plymouth, Mr. Thomas Howard Stewart ; 

 Torquay, Dr. Battersley and Mr. Gosse; Guernsey, Mrs. 

 Buckland; Diamond Ground, off Hastings, J. S. Bowerbaiik; 

 thirteen fathoms off Tremain Bay, Guernsey, Rev. A. M. 

 Norman. 



Examined. — In the living state. 



The general external characters presented to the un- 

 assisted eye are accurately described by Dr. Johnston, in 

 his ' History of British Sponges,' p. 85, but the warted 

 appearances represented by Figs. 12, a, h, p. 87, are. not 

 strictly natural. This character has been produced by the 

 corymbose terminations of the large radial skeleton fasciculi 

 remaining stationary, while the surrounding coriaceous and 



