SPONGES.-HALLMANN. ,-- 



WD' 



spicules, is about two-thirds to three-fourths of the length of 

 the principal spicules.^ 



This species will probably prove to be identical with £. 

 hilamellatmn, Lamarck. 2 



Locs. — Lendenfeld records the species from Western Aus- 

 tralia, and the type-specimen is labelled to that effect. All the 

 remaining specimens, however, are from the eastern coast. 

 Port Jackson (Austr. Mus. Coll.) ; Coast of Queensland, seven, 

 miles south-south-east of Double Island Point, 32-33 fms. 

 ("Endeavour.") 



Genus Rhaphidophlus, Elders. 



1870. Rhaphidoplihis, Ehlers, "Die Esper'schen Spongien" 

 (Erlangen), 1870, pp. 19, 31. 



1870. Tenacia, O. Schmidt, "Grundziige einer Spongien- 

 Fauna des Atlantischen Gebietes," 1870, p. 56. 



1875. Echinoriema, Carter, Ann. Mag. Nat. Hist. (4), xvi.„ 



1875, P- 185. 

 1888. Clathriopsamma (pars), Lendenfeld, Cat. Sponges 



Austr. Mus., 1888, p. 227. 



As in Clathria, the main skeleton is a reticulation of 

 ivell-developed horny fibres cored by {principal) styli and 

 echinated by {typically spined) accessories ; and the micro- 

 scleres are palmate isochelce and toxa. The distinctive 

 feature is the presence of a dermal skeleton of vertically 

 arranged styli, which are derivatives of, and are typically 

 shorter than, the auxiliary styli. The chelce are of one 

 or two kinds, and the toxa, which are sometimes of great 

 length, may lose their distinctive character and may either 

 assume the form of indefinitely-shaped trichitoidal spicules 

 or become indistinguishable from ordinary oxea. 



The abandonment of the genus Rhaphidophlus has been 

 recommended on the ground that the single feature distinguish- 

 ing it from Clathria shows such varying degrees of develop- 

 ment in different species that no hard and fast line can be 

 drawn between the two genera. It should, however, be 

 pointed out that, whereas in some species of the Rhaphi- 

 dophlus-Clathria group the dermal skeleton is composed of 



1 Whitelegge mentions the occurrence in this species of "straight 

 smooth styli, size .8 to 1 by .0015 mm." As I have failed to find any such. 

 I am of the opinion that the spicules observed by Whitelegge were 

 intrusive. 



2 Since writing the above I have seen Hentsehel's description of 

 E. bilamellatum (Fauna Sudwest-Australiens, Bd. iii., 1911. p. 385), and 

 have now no reason to doubt that E. elegavs is identical with that 

 species. 



