REPORT ON THE MONAXONIDA. ix 



Schmidt, in his work on the Atlantic Sponges/ makes the following main 

 divisions, which represent his latest independent classification : — 



1. Hexactinellidse. 



2. Lithistidx. 



3. Halisareinx and Gumminex. 



4. Geraospo7igix. 



5. Chalinex. 



6. Renierinse. 



7. Suheritidinse. 



8. Desmacidinx. 



9. Ulialinopsidinx. 



10. Ancorinidx. 



11. Geodinidx. 



12. Calrisjinngix, 



Here Groups 5, 6, 7, 8 and 9 correspond to Zittel's Monactinellidfe (Monaxonida), 

 and, at a later date (1880), as has already been pointed out by Yosmaer, Professor 

 Schmidt adopts Zittel's modification, grouping together Nos. 5 to 9 as Monactinellidse, and 

 10 and 11 as Tetractinellidse.^ 



We next come to Mr. Carter's classification of the Sponges, which is as follows : ^ — 



Class SPONGIDA. 

 Order 1. Cuniosa. 



Families — 1. Halisarcida. 2. Gumminida. 



Order 2. Geratina. 



Families — 1. Luffarida. 2. Aplysinida. 3. Pseudoceratida. 



Order 3. Fsarnmonemata. 



Families^ — 1. Bibulida. 2. Hircinida. 3. Pseudohircinida. 



Order 4. BapMdonemata. 



Families — 1. Chalinida. 2. Cavoolialinida. 3. Acervochalinida. 4. Pseudochalinida. 



Order 5. Echinonemata. 



Families — 1. Ectyonida. 2. AxinelUda. 



Order 6. Holoraj-iliidota. 



Families — 1. Eerderida. 2. Suberitida. 3. Pachytragida. 4. Pachastrellida. 5. 

 Potamospongida. 



Order 7. Hexactinellida. 



Families — 1. VitreohexactineUida. 2. SarcohexactineUida. 3. Sarcovitreohexactinellida. 



In this scheme the following families are Monaxonida : — 



Chalmida. 

 Cavochalinida. 

 A eervochalinida. 



Pseudochalinida. 



Ectyonida. 



AxinelUda. 



Renierida. 

 Suberitida. 

 Potamospongida. 



All these schemes of classification have been fully discussed by Dr. Vosmaer in his 

 useful and comprehensive work on the Porifera, in Bronn's Klasseu u. Ordnung. des 

 Thierreichs, a work which has been of great service to us in compiling these pages ; 

 hence no discussion is needed here, and we give them, as shortly as possible, only 



1 Grundzuge einer Spongien-Fauna des Atlantischen Gebietes, 1870. 



2 Spoug. Meerb. von Mex., pt. 2. 



2 Ann. and Mag. Nat. Hist., ser. 4, voL xvi. p. 126. 

 (zooL. chall. EXP. — part LIS. — 1887,) Nnn h 



