124 



concave below, through which the polype protrudes. The 

 cells are arranged in alternate rows, and are about three 

 times as long as they are wide. About December, January, 

 and February, numerous yellow semi-translucent sacs pro- 

 trude irregularly from all parts of the surface, which are 

 filled with a gelatinous fluid, which afterwards becomes 

 granular. On examination they appear to rise from the 

 sides of the cells, and make their external appearance 

 through the polype mouths, and finally grow to nearly twice 

 the length of the cells. The production of these sacs, is the 

 destruction of the polypes of the cells in which they grow. 

 The polype is active, with twelve ciliated tentacula in a 

 single circle. 



F. LINEATA. Encrusting; cells oval, radiating from a 

 centre; apertures armed with numerous horizontal teeth 

 pointing towards the centre. 



Flustra lineata, Turton's Lin., vol. 4, p. 665. Johnston's 

 Brit. Zooph., p. 288, pi. 28, fig. 4. 



Hab. On stones in pools between tide marks, common. 

 Polperro, Whitsand bay. Goran. Fowey, &c. 



This encrusting species, appears to be enveloped in doubt 

 and obscurity. It occurs in patches of about one inch 

 diameter, but most frequently about one half or three-fourths 

 of an inch. The cells are oval, in juxtaposition and very 

 small. The apertures are armed with numerous slight 

 horizontal teeth which meet about the centre; sometimes 

 the teeth on one side are very greatly developed, while those 

 of the other are nearly abortive ; but in ail cases from the 

 presence of these teeth, the cells are hardly to be distin- 

 guished by the naked eye. On the distal margin are two 

 long diverging spines. 



Several gentlemen well acquainted with this department 

 of Natural History, have expressed a doubt as to the cha- 

 racter of this species; but though they have considered it 

 as an abnormal condition of some other species, they have 

 not even named the one to which they suppose it to belong. 

 After many examinations of many specimens, I cannot dis- 

 cover the reason for this opinion. However, to ascertain the 

 probability of such a deviation, I have procured specimens 

 from twenty-five localities, differing from each other, and 

 J\ir. Peach has procured me several others, from Goran and 

 the neighbourhood, and a few have been procured from the 

 coast of Devonshire, all of which possess the same characters, 

 which if abnormal is very remarkable. 1 believe it to be as 

 good a species as any other in the list, though it seems not to 

 be the Flustra lineata of Johnston's work. 



