196 "ENDEAVOUR" SCIENTIFIC RESULTS. 



Megascleres. — 



(i.) The stoutest styli are 5.5 ^ in diameter in one speci- 

 men, 7 fi in a second, and of intermediate stoutness 

 in the third. 



(ii.) The longest styli are 290-320 ;/ in length ; 5 // in maxi- 

 mum diameter in the first specimen, 6.5 in the 

 second. 



(iii.) Acanthostyll, 45-56 x 5-6 ]i. 



(iv. ) The special dermal styli are usuall}' less than 

 130 X 4^t. 



Microscleres. — 



(i.) Larger chelae, 14-18;* long. 



(ii.) Contort chelae, 8-1 1 ;«. 



(iii.) Toxa : observed lengths, 40-415 >t. 



Dendy's identification of this variety with those quoted as 

 synonyms is confirmed by an examination which I have made 

 of pieces of their type-specimens. 



Loc. — Port Phillip {Carter; Dendy; Austr. Mus. Coll.). 



Rhaphidophlus tvpicl'S, var. obesls, nom. nov. 

 (Plate xx\iii., fig. i, and fig. 40.) 



The sponges described by Whitelegge under the name of 

 Clathria typica agree among themselves and differ from those 

 of the other varieties by virtue of their low stature, and their 

 non-branching stoutly proportioned lamellar, or, at times, 

 submassive habit. They comprise nine specimens, all of which 

 are in a dry, macerated, and dermally denuded condition. The 

 specimen of most symmetrical shape has the form of a thick 

 sessile plate, sub-circular in outline, thinnest along the slightly 

 and irregularly notched margin, and with both surfaces 

 rendered very uneven by incipient outgrowths. This specimen, 

 which is greater in height than any of the others, makes some 

 approach in habit to the variety anchoratus, though it is well 

 distinguished from any known example of the latter by virtue 

 of its much more massive proportions. It measures 150 mm. 

 in height and breadth, and varies in thickness from 10 to 

 15 mm. near the margin, to 25 mm. in the central portion. 

 Although such simplicity of form is rarely attained, the 

 dominant growth-tendency of the sponges of this variety is 

 always in the direction of plate-formation. But almost in- 

 variably the primary plate undergoes proliferation in various 

 ways, occasionally by bifurcation, sometimes by means of 

 additional upgrowths from a slightly expanded base, but most 

 usually bv means of lamellar outgrowths from the side, which 



