THE SPONGES OF THE WEST-CENTRAL PACIFIC 



95 



Text Figure No. 57. Spicules of Oxymycale strongylophora. A: Strongyle, X 182. 



B: The two ends of one of the strongyles, midportion not shown. C : Larger anisochela. 



D: Smaller anisochela. E: Yet smaller, exceedingly thin as isochelas. F: Larger sigma. 



G: Smaller sigma. H: Raphide. B-H: X 781. 



Mycale in the family Ophlitaspongiidae. Within the genus Mycale there are 

 two groups which have similar skeletal characteristics, but are very distinct 

 from each other in that one has very fine-grained, dense structure whereas the 

 other is exceedingly coarse and cavernous (see de Laubenfels, 1926, page 

 570). The present species, strongylophora, is like the latter sort of Mycale. 

 The point here emphasized is that we may have two groups of sponges exceed- 

 ingly similar in spiculation but very different as to protoplasm. Contrariwise, 

 we may have two that are very similar as to protoplasm, but very different as 

 to spicules. This brings about very great problems in systematization. Were 

 this species now under consideration to be placed within the family Ophlita- 

 spongiidae, one might just as well put many of the rest of those genera and 

 species, which are now in Desmacidonidae, also in the same family Ophlita- 

 spongiidae. The results would be chaotic. It is the present opinion of the 

 writer that the course of action most in harmony with nature would be to 

 reshuffle the Poecilosclerina completely into families bearing no relationship 

 at all to the present ones but, instead, emphasizing protoplasmic structures. 

 Thus, the sponges now in the genus Mycale might find themselves in two 



