266 MYRIOZOID^. 



sometimes on one side only, and frequently in the centre. 

 Specimens seem to occur in which these appendages are 

 wanting altogether. 



Habitat. On shells from moderate depths. 



Localities. Shetland (Barlee): coast of Antrim (Hynd- 

 man): Hastings (Miss Jelly): Guernsey (T. H.): Birter- 

 buy Bay (A. M. N.). 



Geographical Distribution. Madeira; Algiers (J. 

 Y. J.). 



This eminently characteristic species is readily distin- 

 guished from all other British forms. It grows in some- 

 what circular patches, slightly depressed at the centre, 

 where the cells are much smaller than elsewhere. From 

 this point well-marked rows of cells radiate with perfect 

 regularity towards the margin. A very peculiar appear- 

 ance is given to the colony by the hooded ovicells, which 

 are produced in great profusion. The peristome rises to 

 a considerable height in the fertile cell, projecting in 

 front, and united at the sides to the ovicell, so as to form 

 a wall round the mouth, which conceals the real opening. 

 In some cases it is extended as an arch across the front 

 of the ovicell itself. In fresh specimens the cells are dis- 

 tinctly defined by a raised marginal line. The long, de- 

 pendent avicularia are frequently wanting. 



c. Usually without avicularia. 



ScHIZOPORELLA SINUOSA, Busk. 

 Plate XLII. figs. 1-6. 



LEriiALiA siNrosA, Busk. Quart. Journ. Micr. Sc. viii. (1860), 125, pi. xxir. 



figs. 2, o. 

 EsciiARELLA LINEARIS, ibnua SECiNOAui \, Smitt, ffifv. K. Vetciisk.-Ak. 



Forli. lR(r7, Bihang, 14 and 0',>, pi. xxv. fig.s. 74-77. 



