56 



comparativp: table of 



Name. 



A. truncata, Sludev. 



A. liorridn, Stiulcr. 



A. muricata, Verrill, 

 var. indica, Thomson 

 and Henderson. 



A. australiensin, Hent- 

 scliel. 



A. achrammi, T>. and M. 



Branching. 



Branclied in one plane ; 

 branches arise at 45°. 



Branched in one plane. 

 Brandies distant, from 

 two sides, arising at 

 right angles, then 

 running parallel to the 

 main stem. 



Coenenchynia. 



Rugose. 



Verrucic. 



Bristling with projecting 

 points. 



Very profuse, confined to 

 one plane. 



Branched more or less in 

 one jilane ; lateral 

 twigs at right angles to 

 main stem and larger 

 branches, to which, 

 however, the longer 

 twigs soon become 

 parallel. 



Very thin. 



Very thin, surrounding 

 six flat longitudinal 

 canals. 



Flaliellate, reticu! 

 much branched. 



ate, . Thin. 



Cylindrical, 1-2 mm. in 

 height and 1-1 o mm. 

 in diameter ; sjjicules 

 arranged in eight 

 groups. 



Short, cylindrical or 

 somewhat constricted 

 near the base. Beneath 

 the projecting spicules 

 around the oial open- 

 ing there is a collar of 

 transversely placed 

 spicules. 



2-5'3 mm. in height, 

 with a basal diameter 

 of 0"9 mm., and a width 

 of 1'1-1'2 mm. at the 

 crown ; there are eight 

 projecting spicules at 

 the free end. 



Cylindrical to c u p- 

 shaped ; uppermost 

 peripheral spicules of 

 verructe are in eight 

 groups, each with two 

 projecting spines. 



Cylindrical, slightly elon- 

 gated. Somewhat nar- 

 rower at the base ; with 

 5-10 very long project- 

 ing spines. 



