594 COLLECTIONS FROM THE WESTERN INDIAN OCEAN. 



5. Phyllospongia madagascarensis. 

 Carteriospongia madagascarensis, Hyatt, Mem. Bost. Soc. ii. p. 542. 



Extremely variable in external form, viz. from single flexible 

 cylindrical stems about 2 millim. in diameter to palmate fronds 

 arising from similar stems, forming large compound growths ; the 

 cylindrical form also occurs compound ; the same colony may show 

 transitions from the cylindrical to the palmate type. A spirit-speci- 

 men of the cylindrical form has a pale brownish-yellow colour, and 

 its surface is seen under the lens to be very minutely hispid with the 

 projecting ends of the primary fibres. The primary fibres are mostly 

 somewhat, though slightly, sand-cored near the surface (much less 

 than in C.pcnnatula) ; they measure about *04 millim. in diameter, 

 the secondaries somewhat less; fibres very pale yellow in spirit- 

 specimens, colourless in dry skeletons. Surface-texture much finer 

 than in C. pennatula ; surface never broken up into the ridges and 

 grooves which distinguish macerated specimens of that species. 

 Vents slightly projecting, and sparsely distributed up and down the 

 cylindrical axes ; abundant, not projecting, on one side of the pal- 

 mate fronds, diameter about '7 millim. Consistence in all cases 

 very soft and flexible in the macerated state. Owing to the unbroken 

 character of the surface, this species is best placed under Phyllo- 

 spongia. I am indebted to Dr. Polejaeff for pointing out the 

 importance of this character in Phyllospongia. 



Hah. Amirante Islands, beach and 17 fins. 



Distribution. Madagascar {Hyatt). 



Phyllospongia madagascarensis, var. supraoculata, nov. 

 (Plate LIII. figs. M, M'.) 



Some specimens of firm texture, not readily compressible, with 

 very smooth dense surface ; form simple palmate, much and deeply 

 divided or multicaulate ; sometimes partly cylindrical. Vents very 

 small, viz. about -4 millim. in diameter, on one side of the frond and 

 also on its free margin. Meshes of skeleton very close (i. e. pri- 

 maries only -1 millim. apart at surface) ; sand-cores of primary 

 fibres extending a very short distance below the surface. Colour, 

 in dry state (well preserved specimens), cream to pure white. 



Several small specimens, the greatest height and lateral expansion 

 being about 70 millim. (2f inches). 



Hob. Providence Island, Mascarene group ; African Island, Ami- 

 rante group, beach. 



CAPTERISPONGIA. 



Carteriospjmgia, Hyatt, Mem. Bost. Soc. ii. p. 540. 

 Mauricea, Carter, Ann, $ Mag. X. H 1877, xx. p. 174. 



Curiously enough, these two generic terms were published within 

 four months of each other {Carteriospongia, May. Mauricea, Sep- 

 tember, 1877). As, however, the former, besides having this slight 



