A NEW GENUS OF THE HEXACTINELLID SPONGIDA. 229 



open tubular unbranched and widely netted structure, besides basal cusbion or root of 

 great long anchoring spicula, sufficiently distinguish and separate tbem from our specimen 

 •in question, apart from the shape of the various spicula themselves. In Meyerina the 

 more approximated condition of the glassy fibres composing the stem, the somewhat 

 spiral and therefore to a certain extent whorled nature of outer, pronounced elevations 

 of the same, and marked veil or latticework suggest closer ties with Dendrospongia ; but 

 Meyerina is unbranched, and besides has a birotulate form of flesh-spicule entirely absent 

 in that compared. But, moreover, the Euplectellidae, spite of their looser build of vitreous 

 fibre, have frills bearing some relation to the said whorls, and an exceedingly delicate 

 veil, though their true spicular skeleton, as well as that (A Meyerina, has not such rough- 

 ened nor spino-mucronate anastomotic fibre. In Aphrocallistes its branching character 

 makes a closer approach, so far as mere outward configuration is concerned ; but in the 

 Malaccan as well as Atlantic species the widish tubular branches, relatively thin walls, 

 absence of exterior whorled elevations, and other differences of framework stamp sepa- 

 ration from Dendrospongia. The former genus notwithstanding has scopuline and flesh- 

 spicula, and, at least in A. beatrix, such echinate closely reticulate main fibre as to show 

 relationship with the latter, though not of the closest tie. The massive subglobose 

 species of Dactylocalyx from Malacca, and even the branching forms of this genus from 

 other regions, though possessing an anastomotic network of glassy fibre bearing a certain 

 .resemblance to some parts of Dendrospongia, nevertheless in other particulars strikingly 

 depart from the latter. Such genera as the goblet-shaped Crateromorpha and Labaria, 

 and the " sculptor's mallet "-like Hyalonema, in most aspects show recedence of type 

 from our Zebu representative. 



Again, other genera of the Atlantic and American seas, the purse-figured Holtenia, 

 Rossella, and nut-like Sympagella, the bird' s-nestF her onema, and the felt or blanket sponge 

 Askonema, to wit, present relationships rather with one another than in any specially 

 marked degree to that under consideration. To Aulodictyon and Farrea, however, there 

 undoubtedly seems to be a nearer affinity, if much weight is alone to be placed on the 

 flesh-spicular identity. Examples of neither of those two genera, so far as I am aware, 

 have ever been obtained in a perfect and complete form, save the diminutive F. infundi- 

 buliformis, Carter; but still sufficient is known to yield a useful comparison. Both are 

 to some extent diminutive branching Hexactinellid sponges, but even in this respect widely 

 different from the great, handsome, dendritic Steere's sponge. They are, besides, hollow 

 and less or more tubular, with very thin walls and no trace of whorled tufted branches. 

 In one species of Farrea the closely reticulate vitreous fibre is thickly spined (and rnucro- 

 nate according to Carter) ; there also obtains scopuline, acerate ?, and rosette-shaped 

 spicules, bearing considerable likeness to those of Dendrospongia. 



With all this similarity to species of Farrea in spicular form, considerably departed from 

 in other features, it seems to me that Steere's sponge in reality presents intermediate skeletal 

 'characters between Meyerina, Aphrocallistes, and Farrea, while yet so characteristic 

 from all in several respects, that it is hard even to admit positive close affiliation to one or 

 •other. - I expect the future may reveal some form from the eastern seas that may modify 

 the difficulties of their relationships. 



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