364 ,IMAI;V OF CURRENT RESEARCHES RELATING TO 



formation of bhe larval skeleton, in examples of all the divisions of 

 Echinoderma, and discusses bhe general import of his results, with par- 

 ticular reference to the co-operation of the various components of the 

 cell. The author enters into an analytical discussion of the relations of 

 nucleus and protoplasm, and of the role of the chromatin. His general 

 view is that t lie chromatin functions as a regulative substance, by which 

 the formative processes going on in the cytoplasm are determined. 



Structure of Pentaceros reticulatus.* — D. II. Tennent and V. H. 

 Keiller describe this common West Indian starfish. Of the organs de- 

 scribed and figured, those which seem of most interest are the intestinal 

 caeca. They were sometimes found greatly distended, and stimulation 

 caused contraction. When individuals from which the aboral wall was 

 removed were allowed to remain undisturbed in sea- water, the organs 

 again became distended. Later on they contracted of their own acccord. 

 This supports the view, based in the main upon the similarity of position, 

 that these caeca of the starfish are analogous with the respiratory trees of 

 the Holothurian. 



Coelentera. 



Australian Alcyonarians.f — J. Arthur Thomson and Doris L. 

 Mackinnon report on a collection of thirty-five species made by H.M.C.S. 

 ' Thetis ' off the coast of New South "Wales. The collection has a very 

 definite character, due to the proportionately large number of Isidae 

 (e.g. six species of Mopsea, four new) and of Prirnnoidse (e.g. five new 

 species of Plumarella). These Isid and Primnoid colonies are extra- 

 ordinarily beautiful, and their superficial resemblance to large fronds of 

 Sertularians is very striking. Another feature of the collection is the 

 frequent occurrence of encrusting colonies of Alcyoniiim (Erythropodivm) 

 membranaceum and A. reptans, which grow over Gorgonid axis in a very 

 misleading fashion. 



Keroeididae. £ — Kumao Kinoshita proposes to erect a new family, 

 Keroeididae, within the order G-orgonacea. He has convinced himself 

 that Keroeides is no true Scleraxonian, and must be removed from the 

 Suberogorgiidas. Perhaps the same must be said of Simpson's new 

 genus, Dendrogorgia. The new family, Keroeididae, is defined as follows : 

 Colony erect ; axis rigid, consisting of a central cord and of a cortical 

 layer composed of smooth spicules conglomerated together by a horny 

 matrix ; the axis epithelium remains only at the tips of the branches ; 

 polyps retractile into more or less well-developed calyces : spicules not 

 seal v. 



Excluding Keroeides (and Dendrogorgia provisionally) the family 

 Suberogorgiidae may be characterized as follows: Scleraxonians with 

 distinct axis, which is not jointed, formed of fused spicules and horny 

 matrix, with a rudimentary central cord composed of cortex spicules'; 



* Publications Carnegie Inst. Washington, No. 132 (1910) pp. 111-16 (3 pis. 

 and 2 figs.). 



t Scientific Results of the Trawling Expedition of H.M.C.S. ' Thetis.' Part 13, 

 Alcyonana (Sydney, 1911) pp. 661-95 (22 pis.). 



t Annot. Zool. Japon., vii. (1910) pp. 223-30 (1 pi. and 1 fig.). 



