Dr. J. E. Gray on the " Glass-Rope " Hyalonema. 289 



I described (t. 1, & t. 2. f. 1 & 2) — all the sponges having a flat 

 base, by which they were evidently attached to some marine 

 body. 



Professor Brandt also figured (t. 1. f. 4 & 5) a specimen which 

 has the basal part surrounded by a slender oblong mass of 

 sponge; but this sponge does not show any expanded base, and 

 seems only like a parasitic sponge attached to the base of the 

 coral, as sponges are often found on sea-weeds ; and the figure 

 shows a sponge of a much finer texture, so that it does not seem 

 to be the same kind of sponge as that attached to my specimen 

 or those described and figured by Professor Schultze. 



Observing that the polypes on all sides of the cylindrical coral 

 were equally developed, I came to the conclusion that the coral 

 must have grown in an erect position, so that the animals could 

 all have equal access to the sea and an equal opportunity of pro- 

 curing their food. 



Again, the specimens being sunk in a sponge that had a flat 

 base by which it was attached to some marine body, I concluded 

 that the natural habit of the animal was to develope itself in a 

 sponge, so as to support itself in an erect position ; and this idea 

 was strengthened by finding that the sponge near the part where 

 the coral perforated it was of a more condensed and harder tex- 

 ture than the other parts of it. I concluded that there was a 

 kind of mutual understanding (such as we often find between 

 animals that are parasitic on one another) between the sponge 

 and the coral. 



It was for that reason that I formed for the genus the order 

 before referred to, which I called Spongicolce or Hyalophyta. 

 (See Ann. & Mag. Nat. Hist. 1859, iv. p. 439.) 



It is true that the larger number of the specimens that are 

 imported from Japan are without any appearance of a sponge 

 at their more slender base; but I think it is very probable 

 that the Japanese, who collect them as ornaments for sale, and 

 who generally take ofi" the larger part of the bark of the upper 

 portion of the coral, may also carefully remove any sponge which 

 they may think disfigures the specimen. 



This habit of living sunk in a sponge does not seem to be- 

 long to all the species of the genus, and may not be univer- 

 sal, or even general among the species found in Japan; and 

 that may explain why the specimens imported are generally 

 destitute of any appearance of ever having been immersed in a 

 sponge. 



Professor Barboza du Bocage specially observes that the Por- 

 tuguese species has never been found living in a sponge ; his 

 words are, — "La cohabitation ou Pexistence simultanee sur le 

 meme axis de polypes et d'eponges, qu'on a remarquee sur quel- 



