PKOF. S. J. HICKSON : TWO SEA-PEXS FROM WEST AUSTRALIA. 23 
the genus that has hitherto Ijeen identified from the West coast of Australia, 
namely Ft. hyme^iocaulon. Broch (1910) examined and carefully described 
two specimens of this species from Shark's Bay. One was 94 mm. in length 
and one 140 mm. in length, and therefore it is probable that they possessed 
most of the adult characters. My reasons for believing that tiie young 
specimen from the Wallaby Group is not P. hymenocmdon are : (1) that the 
siphonozooid plate is marginal in P. hymenocaulon and basal in our specimen, 
and (2) that the spicules in the stalk of P. hymenocaulon are smaller and 
more numerous than in our specimen. I do not wish to maintain that these 
reasons are conclusive, but I am inclined to think that the species to which 
the specimen belongs is one of my Group II. 3 (see Monograph on ' Siboga ' 
Pennatulacea, p. 231), represented by such species as Pt. grisenm or Pt. 
malayense. 
