BICELLARIA CILIATA. 69 



Habitat. Ou Algae and zoophytes (especially), and on 

 stonesj shells, &c., from between tide-marks to moderately 

 deep water. 



Localities. Cornwall, on corallines and sponges ; near 

 the Eddystone, not common; Mount's Bay (Couch) : South 

 Devon, on Sertularian hydroids &c., common ; Ilfracombe, 

 rock-pools and dredged in 8-10 fathoms ; Filey, on zoo- 

 phytes and under stones ; Fleetwood, on a buoy ; Menai 

 Straits; Swanage Bay (T. H.) : Tenby (F. Walker): 

 Hastings (INIiss Jelly) : Northumberland, rare (Alder) : 

 south coast of Durham (J. Hogg) : St. Andrews, frequent 

 from the Coralline ground (Dr. Mcintosh) : Ayrshire, rare 

 (Landsb.) : Peterhead and Wick, rare ; Durness, Sutlier- 

 landshire (C. W. P.) : Shetland, 45 fathoms, haddock- 

 ground, Out Skerries, very rare (A. M. N.) : coasts of 

 Ireland, sparingly (W. Thompson). 



Geographical Distribution. Ostend (Van Ben.) : La 

 Rochelle, Gironde (Fischer) : RoscoflP (Joliet) : Bay of 

 Gullmaren, Bahusia (Loven and Lilljeborg) : Heligo- 

 land, 5-6 fathoms ; N. America (Kirchenpauer) : South 

 Africa, var.* (T. H.). 



The enormous development of the spines is the most 

 striking feature of this attractive species. Those on the 

 upper margin, which are of great length, curve inwards 

 over the higher part of the cell, while the solitary onef 

 below is directed upwards, so that the polypide is com- 

 pletely embowered, and, no doubt, is largely benefited by 



* In the South- African form the cells are much shorter than in the 

 British ; the portion below the joint is much less elongated, and the cells are 

 therefore more closely packed together. The avieulai'ium is of larger size ; 

 and the inferior spine, so far as I have seen, is always more or less lateral. 

 The habit seems also to be stiffer. These slight differences have an interest 

 as showing by what almost imperceptible degrees forms are modified and 

 change their aspect. 



t There are occasionally two at the bottom of the aperture. 



