SPOXGES FROM COASTAL BEACHES OF N. S. WALES— WHITELEGGE. 103 



130 in breadth, and 10 mm. in thickness, the peduncle is 75 mm. 

 in length, 5 mm. in its lesser and 35 mm. in its greater 

 diameter. 



Thorecta farlovii, Lendenfeld,'-' is undoubtedly distinct from the 

 var. densa, Hyatt,-- as figured on plate x\ui., yet this fig. 14 is 

 quoted in the Monograph under T. farlovii. 



Hyatt's illustration clearly exhibits " superficially extending 

 oscula tubes and corresponding grooves in the skeleton," which 

 ought — according to the definition of the genus Thorecta — to forbid 

 its admission as a species of that genus. 



The following remarks in reference to the aflSnities of the genus 

 Thorecta are sufficient to show that the author of them had not 

 seen examples of Hyatt's var. densa : — " We may derive it [the 

 genus Thorecta^ from Coscinoderma, which it resembles very 

 closely in the structure of the canal system, and the peculiar 

 arenaceous cortex, by assuming that the skeleton-net, which is 

 very dense in Coscinoderma, has become looser, the meshes wider, 

 and the fibres stouter." 



It is very unlikely that a form such as the var. densa, Hyatt, 

 — which is closer in texture than the type of the genus Coscino- 

 derma — would be placed in the genus Tliorecta. (See Plate xiii., 

 fig. 27), 



It seems highly probable that Thorecta farlovii, Lendenfeld, is 

 identical with SpongeJia jmhnata, Hyatt ; it does not agree with 

 Hyatt's figure 15 on plate xvii , but with one of the "two other 

 specimens" mentioned on page 532. Hyatt remarks that "The 

 largest is a foot broad by nine inches in height, and the surface is 

 pitted with shallow depressions or hollows, about one half of an 

 inch in diameter." The above lines apply to a sponge which is 

 not uncommon on the coast, of which I have seen very many 

 specimens. Lendenfeld's figures of T. farlovii are good representa- 

 tions of this form, but it is quite distinct from Spongelia farlovii, 

 var. densa, Hyatt. A comparison of the figures is sufficient to 

 prove their distinctness. Hyatt's figure exhibits a series of "super- 

 ficially extending oscula tubes," and presents a broken surface on 

 the left lower portion of the frond, which clearly indicates the 

 density of the sponge. Such a broken surface is scarcely possible 

 in a soft wide meshed sponge. 



If the whole of the evidence afforded by the preceding remarks, 

 and the published descriptions and figures are duly considered, it 

 will be seen that Spongelia farlovii, var. densa, Hyatt, really 



21 Lendenfeld— Mon. Horny Sponges, 1889, p. 353. 



22 Hyatt— Mem. Bost. Soc. Nat, Hist., ii., (4), 1887, p. 536, pi. xvii., 

 fiff. 14. 



