A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

 Of Nature trusts the mind which builds for aye." — WORDSWORTH. 



THURSDAY, NOVEMBER 3, 1887. 



THE ZOOLOGICAL RESULTS OF THE 

 ''CHALLENGER" EXPEDITION. 

 Report on the Scientific Results of the Voyage of H. M.S. 

 " Challenger" during the Years 1873-76 under the Com- 

 mand of Capt. G. S. Nares, R.N., F.R.S., and of the 

 late Capt. F. T. Thomson, R.N. Prepared under the 

 Superintendence of the late Sir C. Wyville Thomson, 

 Kt, F.R.S., &c., and now of John Murray, one of the 

 Naturalists of the Expedition. Zoology— Vols. XX. 

 and XXI. (Published by Order of Her Majesty's 

 Government, 1887.) 



THE twentieth volume of the "Zoological Reports of 

 the Voyage of H.M.S. Challenger" contains three 

 memoirs, of which the first is " On the Monaxonida," by 

 Stuart O. Ridley, M.A., and Arthur Dendy, B.Sc. The 

 collection of this group of the Sponges was, in the first 

 instance, intrusted to Mr. Ridley, who, to hasten the 

 completion of the work, was afterwards joined by Mr. 

 Dendy. 



When about ten years ago Prof. Zittel gave the name 

 Monactinellidas to an order of Sponges, the position of 

 this group became for the first time clearly defined. Prof 

 Sollas, some five years later, pointed out that Zittel's 

 name implied a wrong idea, for that the characteristic 

 spicules of the group were just as often " diactinal " as 

 " monactinal," and suggested that, as both these forms 

 were, however, " monaxonid," — that is, having only one 

 axis, which, in the case of the diactinal forms, passed 

 through both the rays— the group should be called 

 Monaxonidaj. As this group represents a division higher 

 than that of a family, for which the termination "idse" 

 stands, all subsequent writers have adopted the name 

 "Monaxonida." This group Sollas now regards as a 

 tribe of the sub-class Demospongiae, but the authors 

 of this Report consider it with Zittel as one of the orders 

 of the class. 



The classifications of Gray, Bowerbank, Schmidt, or 

 Carter, have now little but historic interest, while as for 

 the more recent writers it would even seem as if each new 

 Vol. XXXVII. — No. 940. 



series of novelties described necessitated a fresh shuiifling 

 of the orders, sub-orders, and families. 



In the chapter on the anatomy and histology of the 

 group the subject of the spicules is fully treated. It 

 appears to us that no apology was needed for passing 

 over the writings of Bowerbank on these forms ; and when 

 the authors too modestly refer us for further details as to 

 the nature, &c., of siliceous spicules to, among other 

 volumes, those of this author, we prefer, without meaning 

 the slightest reflection on his great labours, to turn instead 

 to the pages of the present Report. 



The very difificult subject of a nomenclature for the 

 spicules is treated at some length. Those of this order 

 are divided into the two classes of " mega-" and "micro-" 

 " sclera." In each of these there is a very numerous series of 

 forms, all of which get separate names, founded on some 

 prominent distinguishing character of the spicule. Let 

 us hope that the majority of these names may find accept- 

 ance with writers on this group of Sponges, so that one 

 difficulty in its study may be removed. 



Passing over the descriptions of the spongin, the 

 arrangement of the skeleton, and those of the ectosome 

 and choanosome, we must briefly notice a very remark- 

 able structure, which would appear to be quite unique, 

 and which is found in di Sponge {Cladorhiza tridentata, 

 sp. n.) from a depth of 1600 fathoms. The little Sponge 

 in which this occurs is in shape somewhat like a minia- 

 ture watch-stand. Embedded in the soft tissues, all around 

 the upper margin of the concavity, a large number of 

 small yellow globular bodies are found. Each globular 

 body consists of a central, more deeply staining and 

 granular portion, surrounded by and embedded in a 

 matrix of faintly staining, perfectly hyaline ground sub- 

 stance. The granular appearance of the central mass is 

 owing to very numerous embedded cells ; these are irre- 

 gular in shape and nucleated. Other peculiar cup-shaped 

 bodies occur towards the periphery of the Sponge, em- 

 bedded in the matrix. The authors think it probable 

 that the cup-shaped bodies are aggregations of glandular 

 cells similar to those met with in the ectosome of some 

 other Sponges, and hint that the whole structure may be 

 phosphorescent, and serve to attract minute organisms 

 upon which the Sponge feeds. In regaflKd "to the canal- 



