7. Anthozoa (incl. Hydrocorallia). A. Zoantharia. 29 



Carpenter found that, when the polyps of Isophyllia are stimulated by 

 meat juice, the oral disc is drawn downwards by the contraction of the re- 

 tractor muscles of the mesenteries, and the margin of the oral surface is folded 

 inwards over the disc by the action of a well developed sphincter. Meanwhile 

 the stomodseum is everted and mesenterial filaments are extruded through the 

 mouth and temporary apertures in the oral disc. Carmine particles dropped 

 on the oral surface of an expanded polyp are transferred, by ciliary action, to 

 the periphery; if they have been previously soaked in meat juice the cilia 

 usually continue to beat in an outward direction, but occasionally they reverse 

 their effective strokes. The tentacles react quickly to contact and fix the 

 touching object to their knob-like distal ends, which are heavily loaded with 

 netnatocysts. When the end of a tentacle is stimulated with meat extract, the 

 retractor muscles of the polyp contract. In normal feeding, which occurs 

 after dark, small planctonic organisms become fixed to the tentacles, the oral 

 disc sinks and the marginal zone folds inwards until it completely roofs over 

 the tentacles and the depressed oral disc. Into the superficial chamber so 

 formed the stomodseum and mesenterial filaments project and the latter pro- 

 bably digest and ingest the captured plancton, little of which enters the re- 

 duced ccelenteron. There is experimental evidence of the transmission of im- 

 pulses from the ectodermal receptor cells, through the mesogloea, to the endo- 

 dermal effectors (muscles) and even from one polyp to another. The author 

 suggests that the branching cells (> connective tissue cells ) in the mesogloea, 

 extending from the ectoderm to the endoderm, may prove to be primitive syn- 

 aptic neurones. 



Hickson describes Pyrophyllia n. inflata n. from a bottom deposit (156 fa- 

 thoms) obtained in the Gulf of Oman (Persian Gulf). The corals are solitary, 

 slightly bent and horn-shaped, with an inflated base which shows no evidence 

 of attachment. They are 4 to 5 mm. long and 1 mm. wide at the margin of 

 the calyx. Every specimen has 8 stout protosepta, 8 slender metasepta and a 

 laminate columella. The septa (which have no perforations, granulations or 

 synapticulse) and columella are not straight laminae but have a regular undu- 

 lating course. Near the base all the protosepta are fused with the columella, 

 but higher the fusion is not so complete and is irregular. The metasepta do 

 not fuse either with the protosepta or the columella. There is no epitheca 

 (as distinct from the theca). There are 16 costal ridges; 15 to 20 annular 

 ridges mark successive growth- periods. The soft parts seem to have 

 been confined, or almost so, to the upper part of the corallum. P. is sepa- 

 rated from Quynia annulata and Haplophyllia paradoxa by the regular radiate 

 arrangement and invariable number of its septa. G. and P, should be placed 

 in a distinct family Guyniidse, next the Turbinoliidse ; H. seems to be 

 distinct from these and may be only a stage in the growth of a genus like 

 Duncania. 



Pax( 2 ) describes, from Gaussberg, Caryophyllia antarctica, Flabellum ineorb- 

 stans and F. sp. He gives an account of the skeleton of F. inc., referring to 

 its minute structure, centres of calcification, etc. There are 4 regular cycles 

 of septa 6, 6, 12, 24; the 5th cycle consists of 16 septa, 12 at one end 

 and 4 at the other end of the elliptical calyx. The skeleton consists chiefly 

 of aragonite, a small amount of magnesium carbonate and a little organic 

 matter. The body wall consists of a glandular ectoderm, mesoglosa, without 

 cells, a circular muscle layer and parenchymatous endoderm. There are, on 

 the tentacles, button-like batteries of nematocysts, nearly all thin-walled, 

 but here and there among them is a thick-walled nematocyst or a gland cell. 



