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



and structure, which these two Bowerbankian species bear to the Farrea infundihxdi- 

 formis, Carter, which was described two years previously by Carter,^ but was entirely 

 unknown to Bowerbank, is certainly striking. Bowerbank, indeed, says nothing of 

 the elegant floricomes, which Carter's specimen possessed in rich abundance, but it is 

 quite possible that these fine forms may have escaped Bowerbank in the course of 

 his examination, and that accordingly all three species may perhaps l^e united into one. 



The fragment which Bowerbank has designated as Farrea Jistulata consists of a 

 bent tube of 23 mm. in length and 6 mm. in transverse diameter. It is not only open 

 at both extremities, but further exhibits a lateral orifice to which a short tube of equal 

 width is attached. The skeleton with its two or three square lattice-layers consists 

 of smooth, cylindrical beams, with wide central canals. From the intersections of the 

 outer as well as of the inner surface tolerably long tuberculated teeth project. 

 Bowerbank also describes a thin dermal membrane with numerous spicules ; but since 

 the latter are called " acerate " and " contort bihamate," and since, moreover, a sj)ecimen 

 of Hymedesmia johnsoni, Bowerbank, which is distinguished by "acerate" and " trenchant 

 contort bihamate " spicules, was found to have settled in the interior of the tube, there 

 can be no doubt that those free spicules of the outer skin-like casing do not belong to 

 the Hexactinellid any more than the spicules of those Desmacidonids which are firmly 

 fixed in the interior. The whole fragment may have lain dead for a long time on the 

 bottom of the sea before it was brought up, and the width of the central canal of the 

 beams is on that supposition readily explained. 



Farrea Iwvis is the name given by Bowerbank to a new species, of which he 

 possessed only a small fragment, consisting of a tube-like siliceous network from 4 to 5 

 mm. in breadth, and scarcely 1 cm. in length. Since the entire system of beams which 

 encloses approximately square meshes only forms a single layer, Bowerbank looks 

 upon this as a " dermal network." The beams of the network are smooth throughout, 

 and so too are the long conical teeth which project outwards and inwards at right angles 

 to the intersections. The central canals, of which two, or sometimes even three, lie close 

 to one another, are very wide, and become confluent at the angles. 



Since the small fragment found in dredged sand was provided only in one small 

 place with a thin skin consisting of a dried soft mass without any spicules, it may be 

 inferred that the skin did not belong to the sponge, and here too, the breadth of the 

 central canals was caused by longer solution in sea-water. Bowerbank finally notes 

 the great resemblance between his Farrea lievis and the branched, partially anastomos- 

 ing, tubular network, figured by Saville Kent^ and designated Farrea occa. He also 

 calls attention to the fact, that that branched tube-like form agrees with a certain 

 " Farrea tubulata." I have carefully endeavoured, but to no purpose, to discover in 



1 Ann. and Mag. Nat. Hist., vol. xii. p. 448, 1873. 



2 Monthly Micr. Journ., pi. Ixiv. fig. 12, 1870. 



