B-18 



the mouth of the polyp when the tentacles are retracted and thus 

 form a conical operculum. The living colonies are light red or 

 salmon-pink, but the colors fade to white in preserved specimens. 

 The species occurs in the eastern and western North Atlantic 

 generally at depths of 50 to 200 fm. 



In the historical survey P. reseda was only found in Norfolk 

 Canyon at approximately 400 m. In the field study this species 

 was fo\ind at 450 m in Baltimore Canyon, and at 560 m in Lydonia 

 Canyon. 



Aaanella arbusaula (Johnson) 



Mopsea avhusaula^ Johnson, 1862:245 



Aaanella arbusaula, Kukenthal, 1919:578 



Aaanella normani, Verrill, 1878a:212; 1883:14; 1922:44 



Aaanella afbusaula^ Deichmann, 1936:243 



As in other members of the family Isididae, Aaanella arbusaula 



can be recognized by its distinctly jointed or segmented axis. 



The axis, which is easily seen in living colonies because of the 



thinness and transparency of the overlying coenenchymal tissue, 



is composed of two types of alternating segments: white, purely 



calcareous internodes and brown or amber colored nodes formed 



from a proteinaceous horn-like skeletal material. In Aaanella 



arbusaula the base of the colony consists of a multibranched 



calcareous structure which acts as an anchor- like support on soft 



substrates. The calcareous internodes are much longer than the 



nodes and increase in length higher up on the colony. However, 



branches arise only from the nodes - three or four per node on 



the stem and larger branches (arranged in an irregular but somewhat 



spiral pattern around the axis) but only one or two per node on the 



