288 •ENDEAVOrK" SCIENTIFIC RESULTS 



EcHixocHALiXA, Thiele {emend). 



1903. Echinochalina, Thiele, Kieselschwamme von Ternate, 

 ii., 1903, p. 961. 



Sponge of various habit; in some cases, like Echino- 

 clathria, consisting of a honeycomh-like reticulation of 

 thin laniellce. Skeleton a reticulation of horny fibres cored 

 by smooth cylindrical spicules — either monactinal or 

 quasi-diactinal — and echinaled by smooth conoidal styli. 

 The former spicules represent the auxiliary, the latter the 

 principal, niegascleres of other MyxUlince : no other kind 

 of niegasclere is present. Microscleres are typically 

 absent. 



1 he genus Echinochalina was introduced by Thiele for a 

 species which he regards as identical with Ophlitaspongia 

 australiensis, Ridley. In expressing the opinion that the 

 species should be removed from the genus to which Ridley 

 assigned it, Thiele savs, "eher scheint sie mir sich an Echino- 

 dictyum anzuschliessen, da sie wie diese Gattung Ziige von 

 gleichendigen Nadeln enhalt, von denen ungleichendige 

 abstehen ; wahrend aber bei Echinodictyum die gleichendigen 

 Spicula grosse Amphioxe sind, sind es hier schwache Amphi- 

 strongyle und die abstehenden Style sind hier glatt, bei Echino- 

 dictyum stachlig. " Topsent is also of the opinion that Echino- 

 chalina is related to Echinodictyum, for he says,i "II ne se 

 distingue du genre Echinodictyum qu'en ce que les spicules 

 qui herissent les fibres sont de styles lisses, les Echinochalina 

 etant, en somme, aux Echinodictyum ce que les Ophlitaspongia 

 sont aux Clathria.'' Both writers, however, have disregarded 

 certain very important differences in the spiculation of the two 

 genera, which render it highly improbable that they are in any 

 way closely related : as an example of such a difference it may 

 be mentioned that, whereas in Echinodictyu]ii there are typi- 

 caly three kinds of niegascleres, there are in Echinochalina 

 only two. 



Besides Echinochalina australiensis, Thiele includes in his 

 genus Echinoclathria glabra, Ridley and Dendy, and Thalas- 

 sodendron digilata, Lendenfeld ; Whitelegge has since added 

 a fourth species, Echinochalina retictdata, and two others are 

 described in the present paper. Of these E. glabra and E. 

 reticulata are of special interest, since both in their honeycomb- 

 like external structure and in the forms of their spicules they 

 bear so striking a resemblance to species of Echinoclathria 

 that their close relationship to the latter seems indisputable. 

 One can therefore assert with some confidence concerning 

 these two species that they differ from Echinoclathria only in 

 the fact that their fibres are cored, not by principal spicules, 



1 Topsent— Arch. Zool. Exp., Notes et Eevue, 1904, p. xciii. 



