104 HISTORY OF BRITISH ZOOPHYTES. 



1. CLAVA MTJLTICORNIS, P. S. Pallas*. 



Hab. Parasitical on seaweeds, corallines, etc., between 

 tide-marks; Harwich, Pallas. Not uncommon. The po- 

 lypes are gregarious, about half an inch in height, with a 

 knobbed, rose-coloured, fleshy head, with scattered filiform 

 tentacula, which the creature can elongate at will, though 

 not so much as the Hydra. Dr. Coldstream says, that after 

 being kept in sea- water for some hours, some of the animals 

 protrude the inner surface of the mouth so as to present a 

 convex disc, with the tentacula ranged round it. 



Genus II. HYDRACTINIA, Van Beneden. 



Gen. Char. Polypes naked, gregarious, united on a common 

 crustaceous base ; tentacula in one subalternating circle ; eggs 

 or bulbules sessile, clustered on untentaculated individuals. 

 Johnston. 



1. HYDRACTINIA ECHINATA, G. Montagu. (Plate I. fig. 1.) 

 Hab. On old univalve shells, from deep water. Not un- 

 common. 



* The name affixed to the specific character by Dr. Johnston, is that of 

 the person who, so far as he could ascertain the fact, has added the species 

 to the British fauna. Pallas was bora in Berlin. 



