﻿276 "ENDEAVOUR" SCIENTIFIC RESULTS. 



Echinoclathria is ultimately separable from Ophlitaspongia 

 only by virtue of its characteristic honeycomb-like structure ; 

 for although the auxiliary spicules of the former are typically 

 quasi-diactinal, yet in E. carteri, as in the species of Ophlita- 

 spongia, they are stylote. This structural peculiarity of 

 Echinoclathria (and of Aulena) is, however, theoretically of 

 questionable generic -value, inasmuch as it is probably nothing 

 more than the extreme specialisation of a not uncommon mode 

 of growth, and is, in fact, actually attained in other genera 

 in the case of Plectispa macropora and certain species of 

 Echinochalina. Consequently, whether the proposal might be 

 to merge Echinoclathyia and Aulena in 0phlitasp07igia or to 

 keep all three genera distinct, no serious objection could in 

 either case be raised, but the more reasonable course seems 

 to be to regard the series of forms which they embrace as con- 

 stituting two genera, with the line of division falling between 

 Ophlitaspongia and Echinoclathria rather than between Echi- 

 noclathria and Aulena. 



I might here remark that the peculiar genus Allantophora, 

 Whitelegge,! which its author regarded as intermediate be- 

 tween Ophlitaspongia and Echinoclathria, offers no justifica- 

 tion for its retention amongst the Myxillinre, and perhaps had 

 better be placed, provisionally, with the Mycalinae. In its 

 microscleric characters, the genus — which is represented by 

 but a single species — stands unique ; but of known forms it 

 perhaps most nearly approaches the equally peculiar Crambe 

 cratv.be, O. Schmidt. 2 Apart from a certain amount of 

 similarity in the formation of their fibres, an argument in 

 favour of a relationship between the two lies in the possibility 

 of an homology between the desmoids of Crambe and the 

 microstrongyles of Allantophora. I cannot agree with White- 

 legge that in A. plicata, the so-called echinating spicules are in 

 anv wav different from those of the fibre-axis. 



EcHiNOCL.'VTHRiA FAVUS {Carter), Ridley and Dendy. 



(Fig. 61.) 



1885. Echinoclathria favus, Carter, Ann. Mag. Nat. Hist. (5), 

 xvi., 1885, p. 292. 



1887. Echinoclathria favus, Ridley and Dendy, "Challenger" 

 Monaxonida, 1887, p. 160, pi. xxxi., figs. 4, 5, 5a. 



1 Whitelegge— Mem. Austr. Mus., iv., 1907, p. 505. 



2 Thiele— Arch. f. Nature., 1899, p. 87. 



