510 REVISION OF THE AXINELLID^E, ii., 



ingly-disposed spicules occur on the main fibres, but are rare or 

 absent on the connecting fibres. The spiculation is almost 

 identically the same as that of A. plicafa, the chief point of 

 difference being that the microstrongyla are much more various 

 in form and size, and frequently pass into spherulse. 



Zoc. —Port Phillip. 



Introductory. — The species is represented in the Australian 

 Museum by two half-specimens from Port Phillip, and a com- 

 plete spe^men (of somewhat different habit) the locality of which 

 is uncertain; in addition, a third half-specimen is included 

 among the original specimens described, by Dendy, as Sigmaxi- 

 nella ciocalyptoides, — viz., the one referred to by him as R.N. 338. 

 The last-mentioned, liowever, does not constitute a fouith ex- 

 ample of the species, but is plainly only the other half of one of 

 the Australian Museum specimens. All the specimens are well 

 preserved in alcohol. 



External features. — The two Port Phillip examples are massive 

 sponges, of erect, somewhat quadiangulately prismatic shape, 

 slightly narrowed below to form a broad base of attachment, 

 and with a very rugged, monticulate upper surface (PI. xxx., 

 tigs. 4, 5) : the slightly larger is 115 mm. in height, and would 

 measure, if complete, about 60 or 70 mm. in breadth and in 

 thickness. The third specimen (PI. xxxi., fig.3), which is very 

 much smaller, — measuring only 55 mm. in height,— is similarly 

 massive in its lowermost portion, but divides above into many 

 separate (or more or less incompletely separate) tapering digita- 

 tions of various size, the largest measuring 25 mm. in length and 

 5 or 6 mm. in diameter at the base. The difference in habit in 

 the two cases, however, is probably to be regarded only as one 

 of degree, since the rugged character of the distal surface of the 

 more massive specimens is such as might be due to incipient 

 digitation. 



The whole surface, including that of the processes, is covered 

 with conuli formed in the same manner as 'vi\ A. plicata; they 

 are sometimes low and sharp, sometimes acuminate or even 

 filiform, up to 2 or 3 mm. in length, and situated at an average 

 distance apart varying from one to several millimetres. The 



