BY WILLIAM A. IIASWELL, M.A., B.SC. 1021 



dependent on the power which the latter possesses of killing or 

 stunning by the action of its thread-cells small organisms that 

 approach the neighbourhood of its tentacles — a plentiful supply of 

 food being thus provided for the anemone itself and for am other 

 animal, such as the hermit-crab or the colony of Phoronis that 

 may live in association with it, and common enemies being at the 

 same time warded oft'. In return for this the Phorones help to 

 build and to strengthen the protecting case in which the 

 Cerianthus lives. 



ON THE PYCNOGONIDA OF THE AUSTRALIAN COAST, 

 WITH DESCRIPTIONS OF NEW SPECIES. 



[Plates LIV., LV., LVL, LYTL] 



By William A. Haswell, M.A., B.Sc. 



Very few Australian species of Pycnogonida have been described. 

 In the list of the known members of the order given by Hoeck in 

 his Report on the Pycnogonida of the Challenger Expedition (188 1) 

 there are only seven Australian species mentioned and of these 

 seven, several are rather to be regarded as belonging to the deep-sea 

 fauna than to the fauna of Australia. 



The following is a list of all the Australian forms now known : — 



Fam. NymphonidjE. 



Nymphon validum, n. sp. Port Stephens. 

 Nymphon aequidigitatum, n. sp. Port Jackson. 

 Nymphopsis armatus, n. gen et sp. Port Molle. 



Fam. C'OLOSSENDEID.E. 



Ammothea longicollis, n. sp. Port Jackson. 

 Ammothea assimilis, n. sp. Port Jackson. 



