(18) Farrea spec. I.e., p. 4i77, S. Penguin Island (Crozets) 46" 16' S., 48" 

 27' E., 2926 m.=1600 ftlis. 



(19) HexactineUa spec. I.e., p. 478, S. Possession Island (Crozets) 46" 53' 

 S., 51" 52' B., 1006 m.= 550 fths. 



Lately two species were collected by the "Pola" Expedition. These I 

 described in the " Bericht der Commission fiir Oceanographische Forschungen, 

 Zoologische Brgebnisse XVI ", in 1900. They are : — 



(20) Aulocystis grayi (Bwbk.) I.e., p. 1, pi. I-II, Red Sea 22" 51' 5" to 26° 75' 

 N., 490-868 m.^268-474 fths. 



(2n Tretoealyx polx F. E. Sch. I.e., p. 9, pi. Ill, Red Sea 17" 42' 2" to 25° 

 57' N., 841-820 m.= 186-449 fths. 



Some of the young " Investigator "-Hexactinellida described in my pre- 

 vious Memoirs as distinct species can now be identified with sufficient certainty 

 as youthful forms of other species, so that the total number of the species col- 

 lected by the " Investigator" appears slightly reduced. 



