57 



SPECIES OF ACAI^TKOGORGIA— continued. 



Polyps. 



Occur in spirals 

 around the 

 branches. 



In 



short spirals 

 over the whole 

 cccnenchyma, so 

 that the latter is 

 almost hidden. 



Densely crowded 

 all round the 

 stem and 

 branches. 



Irregularly dis- 

 posed ; crowded 

 at the tips of the 

 brandies, more 

 distant below ; 

 no true opercu- 

 lum, but spicules 

 on base of ten- 

 tacles. 



Alternate. 



Axis. 



Horny, fle.xible, 

 yellowish-brown. 



Thin, flexible. 



Dark brown, 

 fading to light 

 yellow in the 

 younger parts ; 

 covered with 

 close-set furrows 

 at the base. 



Horny, brown or 

 yellow grey, 

 approaching 

 white in twigs. 



Very black. 



Spicules. 



((() Oa-nenchynia — 

 spindles some- 

 times cluli-shaped. 



(h) Verrucio — bent 

 spindles ; those at 

 the apex are long 

 and bent at the 

 base, covered with 

 spines, wliich are 

 often branched. 



((•) Tentacles — short 

 spiny spindles 

 arranged trans- 

 versely. 



('0 Verrucfe — spiny 

 spindles feebly 

 bent. 



(h) CVi-nenchyma — 

 (1) r a lu i fi e d, 

 plate-like, with 

 numerous sharp 

 spines ; (2) spiny 

 spindles curved or 

 forked. 



(1) Ccenenchyma — 



(a) simple, some- 

 what curved spin- 

 dles, with few 

 small warts 039 

 mm. in length ; 



(b) spindles with 

 strong lateral out- 

 growths leading to 

 X- and H-shajjed 

 forms O'll mm. in 

 length. 



(2) Verrucaj — sim- 

 ple spindles. 



(3) Tentacle base — 

 small, curved, flat, 

 irregular, 0-12 mm. 

 in length. 



Colour. 



Notes. 



r.rown. 



The spicules of the 

 ccenenchyma recall 

 those of Paramu- 



White. 



White. 



Closely resembles 

 both A. spiiiosa, 

 Hiles, and A. 

 muricata, Verrill, 

 but ditfering from 

 the latter in 

 polyps and sj^ioules. 



Near A. ridleyi, 

 Wright and 



Studer. 



