334 SUMMARY OF CURRENT RESEARCHES RELATING TO 



At present, the two lines of evolution represented by the Corynid© 

 and Clavidfe must be left distinct. In the family Corynidpe there is a 

 development in two directions, towards Myriothelidse {C. gigantea) and 

 towards Tubuhridse. The family Pennaridae dissolves itself into 

 Corynidse and Tubularidse. The other branch of athecate hydroids, 

 with Clavidaa as its starting point, forms a fairly compact series ; the 

 Bougainvillidfe deserve to be kept distinct, and the Eudendridaa have 

 a peculiar position as an independent family. The Haleciidae form the 

 starting-point for the various families of the thecophorous hydroids, 

 and are in turn derived from Bougainvillidse. Here, as in many other 

 points, K. C. Schneider's arguments are accepted. In Haleciidaa, the 

 genus Ophiodes forms the transition to Plumularidse, while, on the other 

 hand, the Carnpanularidae must also seek their origin in this family. 



Caryophyllia of Port-Vendres.* — Prof. H. de Lacaze-Duthiers dis- 

 cusses a peculiar habitat and the associated structural peculiarities. 

 The form in question seems to be C. clavus, which usually lives at a 

 depth of 200 metres. The embryos have been carried into a novel 

 environment, and the result is a local modification. They multiply by 

 forming " bouquets " by the superposition and fixation of individuals 

 which show neither fissiparity nor blastogenesis. 



Porifera. 



Skeleton of Astrosclera.f — Mr. J. J. Lister, in describing the struc- 

 ture of Astrosclera loilleyana, a new sponge obtained by Dr. Willey in 

 the Loyalty Islands, points out certain resemblances between its skeleton 

 and that of certain fossil sponges belonging to the Pharetrones. The 

 elements of the skeleton differ however in structure, for while those of 

 Astrosclera are polyhedral masses consisting of radially arranged crystals 

 of aragonite, those of the Pharetrones are more or less modified three- 

 or four-rayed spicules of calcite. ]n certain specimens of Pharetronids 

 from the Tyrol, however, the skeleton has a radiating structure resem- 

 bling that of Astrosclera. Close examination confirms the usual view 

 that this radiation is secondary and due to recrystallisation ; but the fact 

 of its occurrence as the result of a physical process in Pharetronids, and 

 as the result of the activity of living protoplasm in Astrosclera, is of 

 some importance in relation to the problem of the origin of sponge- 

 spicules. 



Species of Hyalonema.J — Prof. F. E. Schulze finds that H. affine 

 W. Marshall, H. apertum F. E. Sch., and H. mahrenthali F. E. ISch., 

 must be united in one species. But the Japanese and Indian specimens 

 are distinct enough to warrant their being regarded as sub-species, — 

 H. affine japonicum and H. affine reliculatum respectively. 



Protozoa. 



North Atlantic Thalamophora.§— Herr Hans Kiser reports on the 

 collection of the Norwegian North Atlantic Expedition (1876-8). There 



* Arch. Zool. Exper., vii. (1899)*pp. 529-62 (1 pi.). 



t Proc. Cambridge Phil. Soc, x. (1900) pp. 189-90. 



t SB. Ges. Naturfreimde Berlin, 1899, pp. 112-29 (1 fig.). 



§ Norske NorJhavs-Expedition, xxv. (1899) 14 pp., 1 pi. and 1 map. 



