574 



Transactions. 



Art. L. — Sponges collected at the Kermadec Islands by Mr. W. B. B. Oliver. 

 By Professor H. B. Kirk, M.A. 



[Read before the WelU)i(j1oii Philosophicdl Society, 5lh October, 1910.] 

 Plate XXVII. 



In May of this year I received from Mr. W. R. B. Oliver a small collection of 

 sponges from the Kermadec Islands. Apparently about eleven or twelve 

 species are represented in the collection. Nearly all of these, so far as I 

 have at present been able to examine them, are species hitherto undescribed. 

 This is surprising, in view of the fact that the " Challenger " collections 

 contained some sponges from the Kermadec Islands, and Von Lendenfeld 

 has described others. It is remarkable also that there is so much distinct- 

 ness from the Australian sponges. It is, however, highly probable that 

 most of these Kermadec Island sponges are found in New Zealand. I hope 

 to deal with the remainder of this collection in a subsequent paper. 



In the descriptions in this paper I have not generally given the diameter 

 of fibres, but the scale of the drawing is shown in each case. All drawings 

 of fibrous skeletons are from specimens treated with water and afterwards 

 carefully dehydrated and brought into balsam. In the dried specimens 

 as received the fibres were in nearly all cases much shrunken. 



Genus Tethya Lamarck. 



More or less spherical Tethyidae, without highly specialized pore-bearing 

 grooves, and without a sand-layer in the choanosome. 



Tethya lyncurium Lin. var. australis var. no v. Fig. 1. 



Sponge about 2 cm. in diameter and 1-5 cm. in height. Surface marked 

 by rounded elevations and depressions, the elevations echinated by the 

 spicules of the brush. No appearance of tesselation. Colour of formalin- 

 preserved specimen pale yellow. 



Fig. 1. — Tethya, lyncurinm var. australis. 

 \a, \l). Styli. 2. Strongyle. 3. Oxeote. 4. Sphcraster. 5. Chiaster. 



The general arrangement of the skeleton is that of the typical T.' lyn- 

 curium. Megascleres are for the most part styli (fig. 1, lo, \h) with [the 

 base rounded, the apex usually blunt but sometimes sharp, and ^the 

 widest part of the spicule about a third of the distance from the base. 

 The styli vary in size; an average size is 1-3 mm. by 0-02 mm. There] are 



