CALCAREOUS SPONGES. 787 



"the instances Avhich are of systematic impoi'tance have been 

 referred to, thougli the list of references is by no means com- 

 plete. Under each genus the date and type-species are given, in 

 ■order to simplify the work of determining the true names of 

 genera in accordance with the laws of priori t}?-, should any of 

 these names be revived for future use. We also give (in brackets) 

 the name under which the type species will be found in the present 

 paper. 



Alcyoncellum Quoy et Gaimard [1833]. 



Type species, as regards calcareous sponges, A. gelatinosum 

 de Blainville, ( = Sycon gelatinoswm). 

 The name Alcyoncellum was originally proposed by Quoy and 

 •Gaimard for certain hexactinellid sponges, but was subsequently 

 used by de Blainville [1834-1837] to inclndeSycon {Alcyoncellum) 

 gelatinosum. Gray [1867] has also used the name for a genus of 

 calcareous sponges, and with the same type species. The name is 

 now regarded as a synonym of both Euplectella and Sycon. 



Amphoridium Haechel [1870]. 



Type species A. viridis Schmidt. 



Schmidt's Ute viridis is absolutely unrecognisable, even 

 generically. 



Amphorula HaecJcel [1870]. 



Type species A. solida O. Schmidt, {=Leucandra solida). 



Artynas Haechel [1870]. 



Type species A. compressus Fabricius, ( = <?r«'«ii« coiiifressa^. 



Artynella Raeckel [1870]. 



Type species A. compressa Fabricius, {=Grantia cotnpressa). 



Artynes Gray [1867]. 



Type species A. comj^ressa Fabricius, {=^Grantia compressa). 



Artynium Haechel [1870]. 



Type species A. comjn^essum Fabricius, { = Grantia compressa). 



Artynophyllum Haechel [1870]. 



Type species A. compressimi Fabricius, {^Grantia comj^ressa). 



AscALTis Haechel [1872]. 



Type species A. canariensis Michlucho-Maclay, (= Leuco- 

 solenia canariensis). 



AscANDRA Haechel [1872]. 



Type species A. cordata Haeckel, {^=Leucosolenia cordata). 



The name Ascandra has been used in almost exactly Haeckel's 

 •sense by several subsequent writers, notably von Lendenfeld, 

 Breitfuss, Arnesen, and various systematists who have followed 



Proc. Zool. Soc. — -1913, No. LII. 52 



