NARRATIVE OF THE CRUISE. 



451 



Family IV. Rossellid^e. 



Subfamily 1. Rossellinae. 



(1) Lanuginella, Osc. Schmidt. 



(2) Pohjlophus, n. 



(3) J{ossella,.CsLrter. 



(4) Acanthascus, n. 



(5) Bathydorus, n. 



Subfamily 2. Crateromorphhui'. 



(1) Crateromorpha, Gray. 



(2) Rhabdocalyptus, n. 



Subfamily 3. Aulochoninse. 

 (1) Aulochonen, n. 



Appendix. 



Hyalostylus, n. 

 Aulocalyx, n. 



Order II. DICTYONINA, Zittel. 

 Suborder 1. Uncinataria. 

 Tribe I. C 1 a v u 1 a r i a. 



Family I. Farueid^e. 

 (1) Farrea, Bowerbank. 



Tribe II. Scopularia. 

 Family I. Euretid/e. 



(1) Eurete, Semper. 



(2) Ptiriphrarjella, Marshall. 



(3) Lefroyella, Wyv. Thorns. 



Family II. MelittioniDjE. 



(1) Aphrocallistes, Gray. 



(2) Melittiaulus, n. 



Family III. Chon'et.asmatid^e. 

 (1) Chonelasma, n. 



Family IV. Volvulinid^;. 



(1) Volvulina, Osc. Schmidt. 



(2) Tretodictyum, n. 



(3) Fieldinyia, Sav. Kent. 



Family V. Sclerothamnid^e. 

 (1) Sclerothamnus, Marshall. 



Suborder 2. Inermia. 



Family I. Mtlicsid^. 

 (1) Myliusia, Gray. 



Family II. Dactylocalycid*. 



(1) Dathylocalyx, Ora}'. 



(2) Scleroplegma, Osc. Schmidt. 

 ?(3) Margaritella, Osc. Schmidt. 



Family III. EuryplegmatiDjE. 

 (1) Euryplegma, n. 

 ? (2) Joannella, Osc. Schmidt 



Family IV. Aulocystidje. 



(1) Aulocystis, n. 



(2) Cystispiongia, Rcemer. 



The Tctractinellida. — Professor W. J. Sollas, who is preparing a Report on the 

 Tetractinellid Sponges collected by the Expedition, writes as follows : — " Although my 

 investigation of the Tetractinellida of the Challenger Expedition is by no means yet com- 

 plete, it is sufficiently advanced to show that considerable additions have been made to 

 our knowledge of this group. The excellent state of preservation in which the spirit 

 specimens have been brought home has afforded me an opportunity of ascertaining the 

 anatomy and histology of most of the recognised genera of the group. This is espe- 

 cially fortunate in the case of the Lithistidse, of the soft parts of which next to nothing 

 was hitherto known. These sponges conform in all essential characters of the canal 

 system to the complicated racemose type which occurs in the majority of sponges, 

 and neither in the characters of the pores, subdermal cavities, nor of the flagellated 

 chambers, offer anything markedly distinguishing the group from the non-cortical 

 Choristid Tetractinellids. 



" The Choristidse have not only afforded rich material for working out the relations 

 of the genera of the group, but furnish also some new forms of considerable interest on 

 account of the reduction and other modifications presented by the Tetractinellid spicules 

 characteristic of the order. 



" It would be premature to discuss questions of distribution before the practical study 



