184 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Ccelentera. 



Structure and Development of Flabellum.* — J. Stanley Gardiner 

 discusses the genus Flabellum and the species F. pavoninum and F. 

 rubrum. He gives an account of the general and minute structure of 

 F. rubrum, and some notes on its post-larval development. In F. 

 rubrum there appear to be three distinct specific or discontinuous 

 variations. 



Noteworthy in the larval development is the occurrence of a mouth 

 almost as large as that of the calicle, and without tentacles or stomo- 

 dseum. The stomodaeum of the adult is probably formed by the 

 external body-wall growing inwards, catching up the edges of the 

 mesenteries in its progress, until it finally reaches the mesenterial fila- 

 ments, which fuse together and help to make the stomodseal wall. The 

 larval conditions — probably brought about by an enormous enlargement 

 of the gastropore in the first place — is perhaps related to the need for 

 rapid growth and abundant nutrition, which might be assisted by a 

 widely open mouth. It is a larval character, not a palingenetic re- 

 capitulation. 



Notes on Variation, Protandry, and Senescence in Flabellum.t — 

 J. Stanley Gardiner finds that F. stokesi and F. nutrix are varieties of 

 F. rubrum, the three forms illustrating discontinuous variability in the 

 same area. When the polyps are 15-17 mm. in length, all the mesen- 

 teries have testes, and those on the larger mesenteries are functional. 

 With increase of size beyond 25 mm. in length, the ova ripen, and the 

 ovaries replace the testes. 



The author discusses signs of senescence (?) in Flabellum and Madre- 

 pora, and suggests that the operative cause is probably the same as that 

 which ultimately produces the death of our forest trees. He thinks 

 that senescence is a general phenomenon in animal life, though definite 

 evidence of this is scarce. He also inquires whether the dying away 

 observed in particular species of coral over large areas may be com- 

 parable to the death of the bamboo after flowering. But no conclusion 

 can be come to without more facts. 



New Pennatulacea and Gorgonacea.t — Th. Moroff has worked 

 over the Pennatulacea in the museum at Munich, and describes several 

 new species, two of Pteroides, one of Pennatula, one of Ptilosarcus, one 

 of Virgularia, two of Pavonaria, one of Acanthoptilum, and one of 

 Gavernularia. He also describes from Japan Pleurocorallium confusum 

 sp. n., Pleurocoralloides g. n., Paramuricea procera sp. n., and Plex- 

 auroides asper sp. n. 



Studies on Graptolites.§ — Sv. L. Tornquist describes forms of 

 Didymograptus, Isograptus, and Mceandrograptus from the lower zones 

 of the Scanian and Vestrogothian Phyllo-Tetragraptus beds. In Didy- 

 mograptus (sensu strictiori), the cavity of the ramifying portion of the 



* Marine Investigation in South Africa, ii. pp. 117-54 (4 pis.).' 



f Proc. Cambridge Phil. Soc, xi. (1902) pp. 463-71. 



t Zool. Jahrb., xvii. (1902) pp. 363-410. 



§ Acta Univ. Lund, xxxvii. No. 5 (1901) pp. 1-32 (3 pis.). 



