Report on the zoological collections made in the Indo-Pacific Ocean ...

SPONGUDA. 593regularity and straightness of the primaries, the secondaries moreconstantly form right angles with them, and the meshes are morecommonly rectangular. (3) The primary fibres are more or less constantlysand-cored ; the core occupies about half the thickness of thefibre.In the characters of the purely horny fibre and the size of themeshes decidua agrees with mauritiana ; the diameter of the fibrevaries from -025 to -063 millim. in the specimen examined (i. e. aboutthe same range as in mauritiana).Hah. African Island, Amirante group, from beach.Distribution. Mauritius, Havana {Hijatt).It is possible that the forms which I have called varieties shouldrank as distinct species ; but until the arrangement of the soft partsis known I prefer to keep them under one specific heading. Youngerspecimens of var. decidua have shallower channels, and one hasbroader tufts and ridges than the rest, thus approaching var. mauritiana.The distinctness of the two forms, found at precisely thesame spot, shows that the diff'erences between them cannot be due tolocality.4. Phyllospongia papyracea.Spongia papyracea, £Jsper, Pflanzentli. Fortsetz. ii. p. 38, pi. Ixv.,pi. Ixv. A. tigs. 1 & 2.Phyllospougia papyracea, Ehlers, Espersch. Spong. p. 22 (? Hyatt,Metn. Bost. Soc. ii. p. 543, pi. xvii. fig. 31).A dry specimen, 195 millim. (7f inches) high by 155 millim.(6| in.) in greatest lateral extent. It is proliferous, a single basegiving rise to the main frond, which is irregularly flabelliform, andto a few smaller strip-like fronds, some of which unite with eachother by their edges at a short distance above the base ; main frondalso proliferating by giving off" at or near its margin, and in oneinstance from the face, a few small secondary fronds similar incharacter to the smaller fronds which arise from the base. Yentsfew, near margin on both front and back of large fronds, diameter1 millim. Primary fibres •035-*053 millim. in diameter ; secondaryfibres about "035 millim. thick; both devoid of foreign bodies. Someminute intermediate fibres or dense strands of sarcode are also present.Meshes of main skeleton about '15 miUim. wide, of dermalskeleton •18-*28 millim. A few scattered foreign bodies in thedermal fibres. In other respects it agrees with Espcr's figure, andhis and Ehlers's descriptions. The latter writer says of the fibresof the Esperian specimens that they are " homogeneous," which mayfairly be taken to imply that, as in this specimen, they contain noextraneous matter. Hyatt, however, assigns to this species specimens(from the Cape of Good Hope) which, from his description, Iunderstand to contain a large amount of foreign material in theprimary fibres.Hah. Mozambique.Distribution. Tranquebar {l^spcr).2ft