46 



I. IJIMA. 



d'. Autodermalia ; pentactins with bovs-like rudiment of 



distal sixth ray; occasionally hexactins Jl/aluscus. 



d". Autodermalia slauractins or pentactins, or both ; with- 

 out rudiment of distal ray and never hexactinie. 



e'. Forms without distinct stalk Vilivllula. 



e". Forms with long, distinct stalk Oralavmorpha. 



c". Discohexaster in two kinds Rossella. 



Bat h y do rus, F. E. Beh. 



Àutodermalia, tliactins, .sta urite tin s or pentactins. Hypodermal pentactin 

 present. Gastralia, probably always hexactins. Parenchymal niegascleres with 

 or without hexactins. Intermedia, oxyhexaster only. 



Artificial Key to Species. 



a'. Autcdei malia, almost exclusively straight diaetins B. baculifer. 



a". Autoderiralia, ]iiedominatingly stauraetins. 

 b'. General surface smooth, without diactinic prost.ilia. 

 c'. Cup-like forms, expanded above and without margin- 

 al fringe of spicules B. laevù. 



c // . Tubu'ar forms, wilh a fringe of marginalia B. Jimbrialus. 



b". General surface with diactinic prostalia. 

 c'. Oxyhexaster with principals exceedingly shoitencd as 



to be almost annulled B. sleilulus. 



c". Oxyhexaster with distinct cylindrical principals B. spinosus. 



11. B. fimbriaius, F. E. Sch. 



Schulze (Chall. Rep. Ilex., p. 152, pi. LVIIi). (Rev. Asc. u. Ross., p. 



533) . 



Loc. : North Paeitie. 



12. B. stellatus, F. E. Sch. 



Schulze (Chall. Rep. Hex., p. 152, pl. L1X 1 — 5). (Rev. Asc. u. Ross., 

 p. 534). 



Loc. : Messier Channel in Patagonia. 



13. B. spinosus, F. E. Sch. 



Schulze (Chall. Rep. Hex., p. 153, pl. L1X 6—9). (Rev. Asc. u. Ross., p. 



534) . 



