III. DESCRIPTION OF THE SPECIES COLLECTED IN THE PACIFIC 

 OCEAN BY THE ALBATROSS. 



HEXACTINELLIDA O. Schmidt. 



Siliceous sponges with hexactine (triaxon) spicules, and derivates of such. 



The Albatross collection of Pacific hexactineUids comprises, besides a 

 number of small, quite irrecognizable fragments and isolated hyalonematid 

 stalk-spicules, from Stations 3G84 (A. A. 17), 3685 (A.A. 25), 3689 (A.A. 134), 4630, 

 4631, 4649, 4651, 4656, 4685, 4709, 4711, 4721, 4732, 4736, 4742, which are not 

 further referred to in this Report, 124 more or less complete specimens and 130 

 fragments sufficiently large for study and at least approximate identification. 



The examination of this material has corroborated the correctness of F. E. 

 Schulze's ' division of the order Hexactinellida into the two suborders Hexas- 

 terophora and Amphidiscophora. 



The collection contains representatives of both suborders. 



Hexasterophora F. E. Schulze. 



HexactineUids generally (or always) with hexasters, always without amphi- 

 discs. The spicules are either all free, or some of them are joined by 

 secondarily deposited silica to form a firm supporting skeleton-net. 



The collection comprises sixty-seven more or less complete specimens and 

 124 fragments of Hexasterophora. 



The examination of these sponges does not make necessary any alteration 

 in F. E. Schulze's most recent arrangement of the Hexasterophora in ten fami- 

 lies ; - all of them find a place in these families. 



' F. E. Schulze. Revision des systemes der Hyalonematiden. Sitzungsb. Akad. Berlin, 1893, no. 

 30, p. 541; Amerikanische Hexactinelliden, 1899, p. 93. 



- F. E. Schulze. Hexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 172. 



