)Q2 Mr. H. J. Carter on the Hexactinellida?. 



Species solid, not excavated, provided with anchoring -spicules and a 

 jlesh-spicule, which is birotulate. 



Birotulate spicule consisting of a straight subspined shaft 

 terminated at each end by eight separate recurved blades 

 (fig. 21) ; or sometimes four- and six-armed, with as many 

 heads, thus assuming the form of a rosette (fig. 22) ; or without 

 heads, and covered throughout or at the extremities with a 

 number of short vertical spines. 



Anchoring-spicules of two kinds, viz. smooth and spini- 

 ferous, twisted into the form of a cord which runs through the 

 head. Free terminations of the spicules unknown. 



Hyalonema Sieboldn, Gray. Japan. (24) 

 lusttamcum, Bocage. Portugal. (25) 



Species more or less globular, excavated, provided with anchoring- 

 spicules, and characterized by the birotulate jiesh-spicule above 

 mentioned. 



Anchoring-spicules of two kinds, viz. smooth and spini- 

 ferous, the latter terminating at its free extremity in a recurved 

 double hook ; termination of the former unknown. 



Holtenia Carpenteri, Wy. Thomson. Sea south of Faroe 



Islands. (26) 

 Pheronema Annce, Leidy. Santa Cruz. (27) 



Grayz, Kent. Portugal. (28) 



Meyer ina claviformis, Gray. Cebu, Philippines. (29) 



Species possessing the birotulate Jlesh-spicule in which the terminations 

 of both hinds of anchoring-spicules are hnown. 



Free termination of spiniferous anchoring-spicule much the 

 same as that above mentioned ; termination of the smooth 

 anchoring-spicule consisting of a double hook or arm, opposite, 

 compressed, slightly recurved, and twice the size of the head 

 of the spiniferous form (PI. XIV. fig. 2). 



Labaria hemisphcerica. Gray. Cebu, Philippines. (30) 



Spicules held together in one part by vitrified fibre and in the 

 other by amorphous sarcode. 



Species tubular, unbranched, closed at the extremity. 



Body sarcospiculous ; lid vitreous. Provided with two kinds 

 of anchoring-spicules and two forms of rosettes, the same as 

 those of Euplectella aspergillum. 



Euplectella cucumer } Owen. Seychelles. (31) 



