596 COLLECTIONS FROM THE WESTERN INDIAN OCEAN. 



appears as if covered by a dense fine incrustation : the vents are 

 small, -5 to 1 millim. across, placed on both sides of the fronds. The 

 primary fibres are strongly sand-cored for some distance below the 

 surface, but little or no sand occurs in the centre of the frond. 

 Var. complexa of Hyatt seems to be founded on fresh specimens, 

 whereas his typical form seems to have suffered from abrasion. 



Hab. Glorioso Islands, beach. 



Distribution. Australian seas (Lamarck); Mauritius (Carter); 

 Zanzibar (Hyatt). 



Obs. I have had the advantage of being able to examine original 

 specimens of Carter and Lamarck while making my identification. 



HIRCINIHXE. 



9. Hircinia fusca. 

 Carter, Ann. $ Mag. N. H. 1880, vi. p. 36. 



Branched cylindrical solid stems, 8 millim. in mean diameter, 

 becoming somewhat dilated at the ends ; conuli of skeleton only 

 about 1 millim. high. Central core of foreign bodies in primary and 

 secondary fibres not large, and sometimes absent here and there ; 

 fibres also coated in places with foreign bodies ; diameter of pri- 

 maries about "18 millim., of secondaries -1 millim. Mr. Carter's 

 description is extremely short, but seems to be sufficient for the 

 purpose of the present identification. A skeleton occurs in the 

 present collection. 



Hab. Eoudeuse Island, Amirante group, 10 fms. 



Distribution. Ceylon (Carter). 



10. Hircinia byssoides. 

 Spongia byssoides, Lamarck, Ann. Mus. Hist. Nat. xx. p. 375. 



Some small horizontally-spreading sessile specimens, about 4 

 millim. in thickness and 30-40 millim. in greatest diameter. Texture 

 in spirit, with sarcode attached, harsh, firm. Primary fibres cored 

 at intervals with small core of foreign bodies, about *07to *1 millim. 

 wide ; all fibres strongly laminate, of light to dark amber-yellow 

 colour. Diameter of primary fibres -1 to - 24 millim., of secondaries 

 •1 to - 14 millim. There is also an intermediate system of narrow 

 uncored fibres, '035 to -05 millim. wide. Colour (in spirit) black. 

 Conuli about 1 millim. high, 2 millim. apart. 



This species agrees fairly well with Lamarck's species, of which I 

 have examined a specimen, but the fibre is decidedly stouter. The 

 form is rather that of his var. t 3, which is described in the words 

 " massis pianulatis"; the original specimen of this in the Paris 

 Museum is firm and harsh to the touch, like the present specimen. 



Hab. Glorioso Islands, Seychelle Islands, 7-12 fms. 



Distribution. Southern Seas or Australia (Lamarck). 



