338 REVISION OF THE MONAXONID SPONGES, ii., 



the longer spicules. They range in length, with increasing 

 stoutness, from 30 to 255 /x, and attain a maximum diameter 

 slightly exceeding 8/z.; the shortest vary in diameter from 2 to 

 4/x. Intermediate forms between the oxea and strongyla, if 

 they exist, are very rare. 



Loc. — Port Jackson. 



Remarks.' — Fetrosia hehes agrees in essential general fea- 

 tures with P. crassa Carter, which, according to Lundbeck, is 

 closely allied to F. dura Nardo, the type-species of the genus. 

 The species is of interest, as it appears to afford indubitable 

 proof of the very near relationship to Fetrosia of the genus 

 Strongylophora Dendy(15), which was placed by its author in 

 the Gelliinai, although regarded by him as being of somewhat 

 doubtful systematic position. I am even inclined to think 

 that the two genera will have to be united, though it is pos- 

 sible that their combined species may be found capable of 

 separation into two genera upon a new basis of distinction. 

 One finds that Thiele (41), prior to the establishment of 

 Dendy's genus, has referred to the genus Fetrosia, without 

 comment, a species {F. strongylata), which possesses exactly 

 the same peculiarities of spiculation as Strongylopkora duris- 

 siina; and these two species differ from Fetrosia Iiebes appa- 

 rently only in one noteworthy feature, viz., the uniformly 

 small size of their dermal oxea. 



Halichondria rubra. 



As Whitelegge(54) has indicated, the specimens labelled as the 

 types of this species and of its variety digilata are similar in 

 skeletal characters to Rhaphisia{Hemitedania, g.nov) anonyma 

 Carter ; indeed, the only feature which at all distinguishes 

 them is their tubular digitate habit (resembling that of Sipho- 

 noc/ialina), and as other specimens occur in the collection 

 which are intermediate between digitate and submassive in 

 external form, this cannot be regarded as of specific value. 

 Whitelegge makes it appear as if the specimens were quite 

 satisfactory examples of Halichondria rubra, and actually 



