DESCRIPTION OF GENERA AND SPECIES. 



Order MONAXONIDA. 



1878. Monactinellidx, Zittel, Zur Stammegcschiclite der Spongien,i p. 9. 

 1883. Monaxonidx, SoUas, Cassell's Natural History, vol. vi. p. 326. 



Siliceous sponges with uniaxial megasclera. 



Suborder I. HALICHONDRINA. 



1885. Halichondrina, Vosmaer, Bronn's Klass. u. Ordnung. d. Thierreichs, Porifera, p. 335. 

 Typically non-corticate ; skeleton usually reticulate ; megasclera usuaUy either oxea 

 or styli. 



Family I. Homorrhaphid^.^ 



1886. HomorrhapMdx, Eidley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii. p. 326. 

 Megasclera all diactinal, either oxea or strongyla ; no microsclera. 



Subfamily 1. RENiERiNiE. 



1870. Renierinse, pars, Schmidt, Spoug. Atlant. Gebiet., p. 39. 



1886. Renierina, Ridley and Deudy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviiL p. 326. 



The spicules may be united together by a small proportion of spongin, but are 



never completely enveloped in it. 



Genus Halichondria, Fleming (Pis. I., II., XLVI.). 



1828. Halichondria, Fleming, History of British Animals, p. 520. 

 1862. Reniera, pars, Schmidt, Spong. Adiiat. Meeres, p. 72, &c. 

 1870. Amorphina, Schmidt, Spong. Atlant. Gebiet., p. 40. 



Skeleton confused, may be fibrous but never regularly reticulate. Spicules oxea or 

 strongyla, usually long and slender. Spongin scarcely appreciable. 



1 Festgabe der pbilosopMschen Facultat zum 50 jahrigen DoctorjubUaum des Professor von Siebold, Munchen. 



2 From Gr. o>oV, one and the same ; and pct0k> needle. 



(ZOOL. CHALL. EXP. PART LIX. 1887.) 



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