82 



this species is perforated witli cylindrical pores of two de- 

 scriptions, larger and fewer ones, which, however, have a diameter 

 of less than a millimetre, and interspersed among these, innumer- 

 able smaller perforations, that are about one-fourth of the diameter 

 of the larger pores. Eelatively considerable areas may, more- 

 over, occur, in which the corallum, while riddled with the smaller, 

 are entirely deficient in the larger pores. "Within a few hours 

 after bringing specimens from the reef, and placing suitable 

 fragments in sea-water, living organisms, in the form of two 

 slender transparent tentacles, were seen protruding from each of 

 the smaller pores, followed by a short portion of a cylindrical 

 semi-transparent body. The aid of a pocket lens was necessary 

 to make out these details distinctly. At first sight, it was 

 suspected that the organisms were allied to the bitentaculate 

 hydroid zoophyte, described many years since, by Mr. P. H. 

 Gosse, under the title of Lar sahellnrun., and which inference, 

 had it proved correct, would have appi'oximated HeJiopora to 

 Millepora and other Hyilroidea. Following, however, the super- 

 ficial examination by sections through the corallimi, laying open 

 the pores from which the tentacles protruded, the true character 

 of their owners was revealed. It was then shown that these 

 tentacles were the terminal appendages of a long, slender, seti- 

 ferous worm, since ascertained to belong to the same family, and 

 to be verv closely allied to, Leucodore ciliata, a species that has 

 been recently accredited with compassing the destruction of the 

 New South Wales oyster beds. Hundreds of these worms were 

 exposed to view in a section of the coral less than one inch 

 square, and either remained ensconced in their respective tubules, 

 or, wriggling out, fell through the water to the bottom of the 

 glass dish, in which they were under examination. The investi- 

 gation was continued, with the object of ascertaining whether 

 any separate organisms were associated with the larger pores. 

 These pores, however, appeared to be hermetically closed, with 

 one or two exceptions, and in which worms, similar in aspect to, 

 but of larger size than those inhabiting the smaller pores, were 

 seen protruding from their orifice^. It appeared reasonable, 



