99 



a Wellington boot cut off lit the neck, with the toe below and 

 heel above. The aperture is oval, subterminal, or like the 

 opening of the shoe ; in the dried state it has a thick, short, 

 tubular rim, which in living specimens is not apparent. 

 Beneath the rim there is frequently seen a short tubulous 

 spine ; this is the rudiment of another cell. This is proved 

 by many specimens showing the different gradations to the 

 perfect cell, and that all the branches arise from this situa- 

 tion, while the other cells are attached to each other by the 

 heel and toe. When the specimens are living, the cells are 

 so transparent that the polype may he seen through ; so 

 that when the animal is expanded two muscles are distinctly 

 to he seen, one attached to the base and the other to the back 

 of the cell, and the animal is found to be encased in a 

 close tubular sheath, to which the muscles are attached, and 

 which is partially protruded when the polype is expanded. 



* * Cells paired with a joint between each pair. 



TUFTED IVORY COLALLINE. Crisia Eburnea. Cells 

 loosely aggregated, cylindrical, bent, tubular; orifices 

 free. PI. 18, fig. 2. 



Tufted Ivory Coralline, Ellis' Coral., p. 39, table 21, no. 6, 

 fig. a A. Sertularia eburnea, Turton's Lin., vol. 4, p. 686. 

 Stewart's Elem., vol.2, p. 440. Cellaria eburnea, Ellis and 

 Solander's Zooph., p. 24, no. 7. Crisia eburnea, Lamou- 

 roux's Cor. Flex., p. 138, no. 244. Fleming's Brit. An., 

 p. 540, no 156, Templeton in Mag. Nat. Hist., vol. 9, 

 p. 468. Johnston's Brit. Zooph., p. 262, pi. 31, fig. 3, 4. 



Ilab. On the roots of sea weed, and the sides of the 

 Corwich crab, abundant. Talland sand bay, Whitsand bay, 

 Lantivet bay, St. Austle bay, Polperro, Port-Holland beach. 

 On the crumb of bread sponge. Common. 



This white calcareous zoophyte varies in height from 

 one-fourth to one inch, and grows in white ivory tufts, many 

 of which are sometimes united to each other at intervals 

 by a creeping fibre. The polypidom is sometimes much 

 branched, and always in an alternate manner. The cells are 

 biserial, tubular, with free apertures, are loosely aggregated, 

 and nearly opposite. They are frosted, or marked with 

 minute dots with plain transparent centres. In young spe- 

 cimens, the branches all arch inwards, and give the small 

 tufts a pretty appearance. The vesicles are very rarely to 

 be found. They are rough or frosted, and somewhat urn- 

 shaped with narrow tubular necks, which are not placed in 

 the centre. 



BLACK JOINTED CORALLINE. Crisia Luxata. Cells 

 closely aggregated, cylindrical, nearly straight, wilh short 

 tubular orifices ; joints black. PI. 18, fig. 3. 



