286 



Table of Species of Pteroeide.'^ inclnded in fhi.s rollecfion, arranged according 



to Kolliker's classification. 



I. Zooid-plate basal. 



(A) Zooid-streak of the keel long and narrow. 



(1) Eachis more than six times longer than broad argenteum group. 



without definite rays P. nigrum, KolUker. 



(2) Eachis at most twice as long as broad . lacazii group. 



11-16 rays P. lacazii var. spinosum, Kijlliker. 



colony very rigid and much contorted, 14 rays P. ilicifolium, n. sp. 



21-27 rays P. tnultiradiatum, KoUiker. 



8-10 rays P. intermedium, n. sp. 



(B) Zooid-streak of the keel short and broad . . griseum group. 



11-22 rays, mostly 14-16 P. griseum, Kolliker. 



15-19 rays P. rohustmn, n. sp. 



II. Zooid-plate median. 



(A) Pinnules ventrally passing on to the keel with a 



cushion ........ caledonicum gi'oup. 



(B) Pinnules without a ventral cushion . . . pellucidum group. 



rays all seem to arise from one point P. mac-andrewi, Kolliker. 



8-10 rays P. andamanense, n. sp. 



pinnules transparent, 17 rays P. indicum, n. sp. 



9-11 rays P. punctatum, n. sp. 



III. Zooid-plate marginal. 



(A) Short main rays which only extend to the polyp 



zone ........ breviradiatum group. 



(B) Long main rays. 

 (AA) Pinnules thick. 



(1) Pinnules with superior zooids ; distinct 



rays ; regular spines ; ventral zooid- 

 streak ...... tenerum group. 



zooid-plate large, 18-23 rays P. flavidum, Kolhker. 



(2) Eays indistinct ; spines irregular ; no 

 ventral zooid-streak ; rarely superior 



zooids ...... sarcocaulon group. 



28-33 rays P. crassmn, KolUker. 

 (BB) Pinnules thin. 



(1) Keel spongy ..... hymenocaulon gi-oup. 



11 rays P. hymenocaulon, Bleeker. 



20-24 rays P. steenstrupi, Kolliker. 



(2) Keel firmer in the interior . . . esperi group. 



ventral zooid-streak, 11-14 rays P. esperi, Herklots. 



14 rays P. esperi, var. armatum, nov. 



Pteroeides nigrum, Kolliker. 



A single colony from which the tip of the rachis has been broken, leaving 

 the nude axis projecting. 



