32 Coelenterata. 



B. Alcyonaria. 



SeeBenham, Crossland, Gravier( 2 ), Hickson( 3 , 4 ), Joubin, Jungersen, Nutting ( 2 j, 

 Roule( 2 , 3 ), Simpson, Thomas, Thomson & Henderson ( 4 ), Thomson & Ritchie. 



Kiikenthal( 3 ) gives a systematic review of the Alcyonacea and describes 12 sp. 

 (11 n.) obtained by the "Valdivia" together with others and from various other 

 sources. Only Glavularia chwii n. is from a depth of over 1000 metres, 

 Xenia antarctica n. , Alcyonium reptans n. , Anthomastus antarcticus n. and 

 Eunephthya antarctica n. are from 457 and 567 metres, the remaining specimens 

 are from the deeper littoral zone. C. ctmni is the first species of C. from 

 deep water in the Indian Ocean. X. antarctica extends the distribution of this 

 genus into the Antarctic, this sp. differs from others in having peculiar warts 

 on the tentacles, the pinnules are elongate, the polyps few and large, coelentera 

 wide, the surface of the colony cuticularised (bearing broad wart-like outgrowths 

 between which are grooves closely packed with sand, sponge-spicules, etc. which 

 in the complete absence of spicules have assumed a protective function), the 

 stornodseum folded, the mesenterial filaments (dorsal) extraordinarily well deve- 

 loped, mesenteries with strong muscle-ridges and there is a preponderance of 

 solid cords of endoderm in conformity with the reduction of the entodermic 

 canals. X. uniserta n. from the coast of S. Africa is not a reef dweller like 

 most species of X. and provides a transition between X. ant. and the ordinary 

 species; the autozooids have no siphonoglyph, a condition probably in correlation 

 with the large number of siphonozooids present. X. ant. and X. unis. are 

 relatively rigid while shallow water forms are softer (as is also the case in 

 the Nephthyidse) perhaps an adaptation in connection with the exposure of the 

 latter to the breaking of the waves. The non-reef-dwelling species (X. unis. 

 and X. capensis) have only two rows of pinnules on each tentacle. A new 

 sub-family Nidaliinse of the Aleyoniidse is formed to contain the genera Nidalia 

 (diagnoses of 5 n. sp.) and Nidaliopsis n. 1 n. sp. There are also described 

 Alcyonium 2 (1 n.), subg. Metalcyonium 1 n., subg. Erythropodium 3 n., Antho- 

 mastus antarcticus n. the first Antarctic species of the genus, and A. elegans n. 

 the second species from S. Africa, Capnella rugosa the first record of this 

 genus from the S. African region, Eunephthya antarctica n., on which male 

 and female products are found in the same polyp and even on the same mesen- 

 tery, also interesting because all the species hitherto described have been from 

 northern seas. The author gives an account of the phylogeny and geographical 

 distribution of the Alcyonacea. He leaves the doubtful family Haimeida? and passes 

 to the Cornularidse, the numerous genera of which are reduced to four. 

 Cornularia is the most primitive in its horny envelope and its non-retractile 

 polyps connected by the basal primary stolon; arising from Corn, is (1) Anthelia 

 in which also the polyps are non-retractile but the stolon consists of a net- 

 work of anastomosing canals and there is a spicular mesogloeal skeleton and (2) 

 Clavularia in which the distal thin walled part of the polyp is retractile into 

 a more proximal stout- walled "calyx" and the spicular armature is considerably 

 increased; in Sympodium - there is probably only one sp. (ccerul&um) the 

 stolon forms a thick membranous base into which the short polyps are re- 

 tractile and also characteristic are the discoidal small spicules. From the 

 Cornularidse 3 families have arisen - (1) Xeniida? from the genus Anthelia, 

 both have retractile polyps but in X. the stolon has become a thick compact 

 fleshy mass surrounding the lower parts of the polyps ; X. antarct. and ivandeli 

 (Iceland), with primitive characters may be placed in the subgenus Ceratocaulon 



