180 THE VOYAGE OF H.M.S. CHALLENGER. 



leno-th of the internodes, including the coenenchyma, is 8 mm., with a diameter of 1 mm.; 

 while the nodes measure 2 '5 by 3 mm. The branching seems to consist of a division 

 of each of the twigs, at the nodal regions, into two portions, which then proceed upwards 

 in a quasi-parallel manner ; the anastomosis taking place by a series of short lateral twigs, 

 al)out 3 mm. in length, which stretch from one node to another. 



The internodes when stript of coenenchyma are found to be broad, flattened, or 

 broadly oval on section ; in the older portions of the colony this is so markedly the case, 

 that while the broad diameter is I'd mm., the short diameter is only 0'575 mm., bevelling 

 ofi" to nothing at the edges ; they are of a bright pink. 



The polyps are scattered all over the branches, with shallow verrucse ; they are 

 somewhat lateral on the terminal portions, and they are not so numerous and indeed are 

 even absent from the dorsal aspect of the colony. The verruca3 are from 0'5 to 1 mm. 

 in height. 



The coenenchyma is thick ; the large spiny spindle-shaped spicules forming a dense 

 layer. 



The spicules measure : — the Stachelkeule, which have sometimes rather flattened 

 heads, 0-24-0-06 ; 0-2-0-1; 0-16-0-06 mm. The one-sided spiny spindles 0-1-0-06 ; 

 0*l-0'04 mm. The warty bent spindles measure 0'24-0"06 mm., these are mostly in the 

 coenenchyma. In the verrucse, the double crosses measure 0*01-0*04 ; 0'08-0'06 ; 

 O'OG-0'04 mm. At the base of the tentacles, the curved s^inj spindles measure 0*3- 

 0"02; 0"24-0'025; 0"22-0"025 mm. A few four-rayed forms are found, measuring 0*04- 

 0'04 mm. iu the polj^ps, where also occur some simj^le spindles with eight small central 

 knobs, 0-04-0-02 mm. 



The colour in spirits is a deep red ; the polyps yellow. The colours when dry fade 

 a good deal. 



Habitat. — Torres Strait. 



Melitodes fragilis, n. sp. (PI. XLI. fig. 1). 



Some few fragments of this small but interesting species were found in a dredging 

 at Amboina ; they were so entangled iu the meshes of the tow that it was impossible 

 to obtain a very accurate idea of the appearance of the perfect colony. It was 

 apparently of small size. 



The largest fragment is a detached branch of 40 mm. in height and 15 mm. in 

 width ; it branches irregularly, but the liranches have a tendency to assume the one plane. 

 The branches are twisted ; in this fragment there is but one anastomosis, which is 

 between two parallel branches, but in other fragments mesh -like anastomoses occur. 

 The internodes which are often curved and twisted vary greatly in length, measuriug 

 4, 8, and 12 mm. in length; in various fragments the laroest are 1-5 mm. in length. 



