NARRATIVE OF THE CRUISE. 



445 



each arm of a six-rayed spicule is applied to the corresponding arm of a neighbouring 

 spicule, both spicules thus becoming enclosed by a common siliceous covering. The 

 connected skeletons of the Dictyonina consist of a lattice-work with irregularly cubic 

 meshes. Spicules belonging to the soft parts may be present or absent. 



" In many sponges which, according to the rest of their organisation, belong without 

 doubt to Zittel's ' Dictyoninen,' I have failed to observe that union of neighbouring 

 spicules by the enclosure of the corresponding approximated branches in a common sili- 

 ceous coating, which he mentions ; on the contrary I found in these cases the spicules 



Fie. 167.— Section of the wall of Walteriaflemmingii, n. gen. et sp., a representative of the Euplectellida? (j). 



either united crossing each other quite irregularly or disposed in a different manner, 

 which also has been already observed by Oscar Schmidt and Zittel ; that is to say, the 

 rays of the spicules were fused with other spicules in the angles between their rays, and 

 thus united into a firm skeleton. 



" On the other hand, in not a few Lyssacina, I have, like Oscar Schmidt, met with a 

 firm union of spicules of a particular kind, sometimes in a very irregular disposition, 

 sometimes by lateral soldering, sometimes of closely approximated parallel spicules con- 

 nected by transverse pieces (synapticulse); this may take place only in the basal portion 



