324 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Hydrocoralline from Rockall.* — J. Arthur Thomson records the 

 occurrence of Stylaster gemmascens from Rockall in the North Atlantic. 



Fossil Corals from Ceram.f — H. Gerth discusses an interesting 

 Hydrozoon fossil from East Ceram which turns out to be a species of 

 Herastriclium. He also discusses what Tornquist called Neostroma, and 

 shows that it is neither a Hydrozoon (Stromatoporoid) nor a Spongio- 

 rnorphid, but a kiud of Actinacis. 



Porifera. 



New Monaxonids.J — E. Topsent discusses the species of the peculiar 

 Monaxonid sponges belonging to the genus Cladorhiza, and describes a 

 well-defined new species G. grimaldii from near Madeira and G. thomsoni 

 dredged by the ' Scotia ' (W. S. Bruce) between Gough Island and the 

 Cape. He also establishes a new genus Euchelvpluma, closely allied to 

 Asbestopluma. 



Hexactinellid Sponge Spicules and their Names.§ — R. Kirkpatrick 

 points out that there are two main groups — one (" holactine ") in which 

 all the rays have an axial canal, the other (" astral ") in which the central 

 end is hollow and the rest solid. The part of the ray with the axial 

 canal is here termed the " actine," the solid part or parts of the so-called 

 ray or ray-system being termed end-spines or "distal appendages." 

 Holactine spicules have only actines. Astral spicules have end spines 

 or distal appendages at the ends of the actines. The author works out 

 a detailed classification of the forms of hexactinellid spicule belonging 

 to these two groups. 



Merlia normani.|| — R. Kirkpatrick has come to the conclusion that 

 this remarkable sponge has both a calcareous and a siliceous skeleton. 

 It is not a parasite growing over and into a calcareous organism ; it is 

 now beyond doubt seen to be a sponge, and nothing but a sponge. It is 

 of unique interest, not only in itself, but also on account of the resem- 

 blance, in some respects, of its calcareous skeleton to certain of the Mon- 

 ticuliporas. 



Affinities of Astrosclera willeyana.f — R. Kirkpatrick refers to this 

 interesting form, which J. J. Lister regarded as an aberrant calcareous 

 sponge. Further investigation has led Kirkpatrick to conclude that it is 

 a siliceous Ectyonine sponge related to Hymerhaphia. It does not secrete 

 aragonite, as was supposed, but has a supplementary skeleton formed of 

 foreign particles of aragonite, at first discrete, and afterwards welded into 

 concrete walls and blocks. 



Development of Sycon raphanus.** — Ernst Hammer describes the 

 ova and their growth, e.g. how the young amoeboid cells ingest and 



* Proc. Roy. Phys. Soc. Edinburgh, xviii. (1910) p. 61. 

 t SB. Nat. Ver. Preuss. Rheinlande, 1909, pp. 17-25 (8 figs.). 

 % Bull. lust. Oc6anographique, No. 151 (1909) pp. 1-23 (2 pis.). 

 § Ann. Nat. Hist., v. (1910) pp. 20S-13 (1 pi.). 

 || Tom. cit.,pp. 288-91. f Tom. cit., pp. 380-3 (1 pi.). 



** Arch. Biontolog., ii. (1909) pp. 291-334 (6 pis.). 



