7. Anthozoa (incl. Hydro corallia). B. Alcyonaria. 39 



corals predominating. No trace of Tertiary organisms could be detected; no 

 basis of old Tertiary limestone was reached. The mass of vegetable matter on 

 the floor of the lagoon (at the rate of accumulation inferred from observations 

 on living Hal.) represents a period of about 800 years and during this period 

 there has been a subsidence of about 150 feet. Hinde points out that the 

 rock in the upper part of the boring is to a large extent a limestone, in the 

 lower part a dolomite or dolomitic limestone. The corals found in the bor- 

 ings comprise 2 Hydrocorallines, 2 Alcyonaria, 13 Madreporaria Aporosa (10 of 

 which belong to the Astrseidse), 6 M. Perforata and 5 M. Fungida. Of these 

 28 genera 22 are living on the reefs or in the lagoon of Funafuti, the other 

 6 are Stylaster, Euphyllia, Galaxea, Siderastrcea, Cycloseris and Goniopora. 

 Hydnophora, Galaxea, Cycloseris and Turbinaria are found only in the lower 

 third of the boring, while Millepora, Lobophytum, Stylophora, Pocillopora, 

 Astrcea, Orbicella, Fungia, Madrepora (one n. sp. is described), Astrceopora, 

 Montipora and Porites range from the top to the bottom. The corals in the 

 upper part (down to 180 feet) are in their positions of growth and often over- 

 grown with Lith., but not much changed; below this level they have been 

 reduced to mere casts. There seems to have been a continuous formation of 

 reef rock from the depth of 1114 feet to the present time. 



Hedley maintains that the lagoon of coral reefs is an area of rapid accumu- 

 lation from both growth and deposition and that if the atoll be stationary the 

 lagoon must in time be filled in, but if subsidence occur the lagoon is preserved. 

 Schwarz combats Gardiner's views [see Bericht for 1903 Coel. p 19, 20] 

 on the formation of coral reefs and especially the importance attached to 

 erosion. He believes that below a few feet erosion does not take place to 

 any appreciable extent and that the formation of coral reefs may be explained 

 by subsidence. See also Gardiner ( :j ). 



B. Alcyonaria. 



See Burchardt. Henderson, Hentschei, Holm, Wilson, and above p 23 Kingsley, 

 P 35 AgassizC., p 39 Hinde, p 37 Sollas, p 38 David & Sweet, David & 

 Halligan & Finckh. 



Pratt concludes that Aleyoniwm exercises considerable choice in selection of 

 food material. Gland cells are present in the stomodaium of A. and all other 

 allied genera examined. Food (and carmine) particles are ingested and sub- 

 sequently digested by the amoeboid endoderm cells of the ventral and lateral 

 mesenterial filaments and of the ccelenteron and canals. Carmine particles are 

 also found in the stellate cells of the so-called "nerve-plexus" which are 

 shown to be amoeboid [see Bericht for 1902 Coel. p 27]. Amoeboid endoderm 

 cells containing carmine particles were observed to protrude processes into the 

 mesoglcea and to assume a condition identical in appearance with the cells of 

 the "nerve-plexus". This system of amoeboid cells is a nutritive plexus 

 by means of which nutriment may be conveyed from the digestive endoderm 

 cells of the zooids to all parts of the colony. 



Hickson gives a preliminary account of the siphonozooids of Pennatula 

 murrayi from the Moluccas (Siboga Expedition). There is a large siphon o- 

 zooid at the base of each pinnule, in addition to many other smaller ones 

 on the dorsal and lateral regions of the rachis. The large siphonoz. differs 

 from the ordinary ones in the large size of its stomodaeuin, rudimentary siphono- 

 glyph and great development of muscles on the lateral mesenteries. 



Jungersen gives a list, a revision of the classification and a general review 



