104 HISTORY OF BRITISH ZOOPHYTES. 
1. Cuava mutticornis, P. 8. 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. Hypracrinia 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 born in Berlin. 
