100 RECORDS OF THE AUSTRALIAN MUSETTM. 



EUSPONGIA PIKEI, Hyatt, Sp. 



(Plate xii., figs. 21 -21a). 



Stelospongia pikei, Hyatt, Mem. Best. Soc. Nat. Hist., ii., 4, 1877, 

 p. 532, pi. xvii., fig. 20. 



Euspongia pikei, Lendenfeld, Aust. Mus. Cat., xiii.. Sponges, 1888, 

 p. 132; id., Mon. Horny Sponges, 1889, p. 279, pi. xxii., 

 figs. 3, 8, 12. 



This species is represented in the Lendenfeldian collection by 

 two specimens, one (No. 57) from Port Chalmers, New Zealand, 

 and the other (No. 351) from the coast of New South Wales. 



In habit the sponge varies from half-cup shape to subflabellate, 

 and in some specimens it is flabellate, with numerous lobate pro- 

 cesses. The sponge may be pedunculate, or have a broad base of 

 attachment. The laraellaj rarely exceed 130 mm. in height, 80 to 

 100 mm. in breadth, and 10 mm. in thickness. The oscula are 

 between 2 and 3 mm. in diameter ; they occur on the rounded 

 margins and are also scattered over the convex surfaces, where 

 they are often prominent. The whole surface is covered with 

 minute conuH, which are situated on the slightly elevated ridges 

 of the reticulation ; between the ridges numerous inhalent pores 

 are situated, their diameter is about 1 or 2 mm., and rather less 

 than that distance apart. Texture in the dry condition, light, 

 spongy, moderately firm and elastic, but easily breaking with 

 slight pressure. Colour, yellowish-gray, with a dull surface, quite 

 unlike that of any other Euspongia known to the writer. 



Skeleton consisting of bundles of trellised main fibres, which 

 curve gracefully outwards towards the surface, these are connected 

 by a series of very fine secondaries. The track of the main trellis 

 bundles is marked by the presence of a thick line of foreign bodies ; 

 the latter appear to be cemented in the spaces of the trellised 

 fibres, and do not, so far as I can determine, form an axial core 

 in the fibres. The stouter trellis-like bundles are from 0-3 to 05 

 mm. apart, and often 5 mm. in diameter, with two or more 

 strands of foreign bodies. The more slender bundles usually have 

 a single thread of sand grains, and are from 0-1 to 2 mm. in 

 diameter. The individual main fibres are 004 mm. in diameter, 

 and are usually separated by spaces about 1 mm. or less. The 

 secondaries measure about 01 mm.; the mesh is angular and 

 frequently elongate, with the longer diameter transverse to the 

 trellised bundles; length of mesh 0-1 mm. 



The form described above closely agrees with Hyatt's figure ; 

 the description has been chiefly drawn from the dry example 

 named Euspongia pikei, by Dr. Lendenfeld (No. 351) ; the latter 

 author, in his account of the skeleton, states that " The main 

 fibres of the skeleton are irregular, flattened, and perforated 

 trellis-like. These perforated plates attain a maximum breadth 

 of 0*25 mm. No foreign bodies are observed in them." If the 



