. MADREPORES." 371 



differ from other corals in not having a smooth skeleton, 

 but one inducted by numbers of small cells for the resi- 

 dence of the living animal : these are very visible in 

 the Madrepore muricata, when the polype is dead and de- 

 composed ; but most distinct in the Oculina ramea, as 

 they are situated at the apparently broken stumps that 

 branch from the trunk of the skeleton (fig. 195, No. 5). 

 Every branch is seen to be covered with multitudes of 

 small pits or dots, scarcely visible to unassisted vision ; but 

 when viewed under the microscope, are found to be cells of 

 the most beautiful construction, remarkable alike for their 

 mathematical regularity and the exquisite fineness of the 

 materials employed in their composition. A magnified 

 drawing of one of the cells is given at No. 6. The living 

 polypes are most beautiful in their native waters ; their 

 varying colours adding to the richness of the hues covering 

 the bed of the ocean. 



CaryopJiilleadce, " Nut-leaf corals." The Caryophillia 

 Smithii is found fixed to rocks ; it is round, and of a dingy 

 white colour. Dr. Fleming says of the plates : " The 

 lamellae are disposed in fours, and may be divided into 

 three different kinds. The first are the highest and the 

 broadest at the margin ; but as they descend into the 

 disc, they become narrower before they join the central 

 plate. The second kind are narrower than the preceding 

 at the margin, but towards the middle they suddenly 

 enlarge and join the middle plate. The third kind are the 

 smallest, and terminate before reaching the middle plate. 

 The space included between a pair of the first kind of 

 plates contains one of the second kind in the middle, with 

 one of the third kind in each of the lateral spaces. Those 

 on the sides are rough, with small scattered tubercles, and 

 their margins are curled. This last circumstance occasions 

 the roughness externally, where the longitudinal strise are 

 the remains of the gills. The plate which occupies the 

 bottom of the cavity is smooth, variously twisted, and con- 

 nected with the base of the lateral plates." 



Dr. Coldstream, writing to his friend Dr. Johnston, gives 



the following interesting account of the animal : " When 



the soft parts are fully expanded, the appearance of the 



whole animal resembles very closely that of an Actinia. 



B B 2 



