42 BRITISH SPONGIAD2E. 



TETHYA CRANIUM, var. 2, ZETLANDICA, Garter, 1. c. 



Surface smooth, interrupted by thick-set papillae 

 irregularly disposed. Sarcode entirely without biha- 

 mates. The young within the body showing the 

 same absence of bihamates, and having the spicules 

 radiatiugly arranged, but not spirally twisted 

 (Carter). 



TETHYA CRANIUM, var. 3, ACOFERA, Norman. 



In most respects like the type, bihamates abundant ; 

 along with the f usiformi-acerate spicula of the skeleton 

 large numbers of fusiformi-acuates occur, consti- 

 tuting perhaps one third of the number of skeleton 

 spicula. 



A single specimen in my collection. 



TETHYA CRANIUM, var. 4, ABYSSOEUM, Carter, Ann. Nat. 

 Hist., ser. 4, vol. xviii, 1876, p. 405, pi. xvi, 

 fig.. 49. 



Bihamates ( 15 1 uo th inch long) twice as large as usual, 

 and under \ inch object glass seen to be covered with 

 minute vertical spines. 



Abundant among the " Porcupine" dredgings in 

 the deep sea between the North of Scotland and the 

 Faroe Islands. 



