176 CEYLON PEARL OYSTER REPORT. 



I have also seen three small isochelse about - 018 millim. long, and two or three 

 siemata, one of which measured about 0"05 millim. from bend to bend; but these 

 spicules are so scarce that I am doubtful whether they are proper to the sponge. 



This is an interesting species, having (if we leave out of account the doubtful 

 microscleres) the spiculation of an Echinodictyum combined with the habit of an 

 Echinoclaihria. It is evidently nearly related to Tuiele's Echinodictyum cavernomm 

 from Celebes (39), but differs in its pale colour and in the presence of the large styli. 



R.N. 325 (Ceylon seas). 



Aulospongus, Norman. 



Massive Ectyoninaa with plumose columnar skeleton, comprising both smooth and 

 spined styli in the spiculation. Without microscleres. 



In my ' Report on a Second Collection of Sponges from the Gulf of Manaar ' (3) I 

 expressed the opinion that Norman's genus Aulospongus (55) was unnecessary, and 

 that the species for which it was established might be included in the genus AxineLla. 

 Further consideration has, however, induced me to alter my views on this question, 

 and to consider the presence of the spined styli as constituting a sufficient generic 

 distinction from Axinella, and, indeed, necessitating the removal of the genus to the 

 Ectyoninse. 



This genus is evidently closely related to Raspailia, and constitutes one of the 

 apparent connecting links between the Ectyoninae and Axinellidae. Thiele (39) has 

 referred to the genus Raspailia two or three Japanese species, one, at least, of which 

 {Raspailia (?) villosa) should perhaps be included in Aulospongus. The Australian 

 Raspailia cacticutis (vide Dendy, 10) may also possibly belong here, and likewise 

 Mr. Carter's Dictyocylindrus sessilis from the Gulf of Manaar (4). 



Aulospongus tubulatus (Bowerbank). 



1873, Haliphysema tubulatum, Bowerbank (8) ; 1878, Aulospongus tubulatus, Norman (55); 

 1889, Axinella tubulata, Dendy (3). 



There are a number of specimens of this sponge in Professor 



Herdman's collection. The species (fig. 3) forms one of the 



most characteristic elements in the Sponge-Fauna of Ceylon, 



and is of especial biological interest as affording an example 



of symbiosis, or perhaps commensalism, between a Sponge 



and an Annelid. I have nothing to add to the account which 



I gave in my ' Report on a Second Collection of Sponges 



from the Gulf of Manaar ' (3). 



Vi &J"'77'' S 'r'Tl R-N. 1, 2, 3 (and others not numbered ; all from Gulf of 



(Bowerb.) ; from Gull ot ' ' v 



Manaar; at. >ize. Manaar (Stats. V., IX., XV., LV., LXL, LXVIIL). 



