a number of coral-girt islands in the neighbourhood, where 

 hares and partridges may be shot, and sluggish Holiithurians 

 captured in abundance at low tide as they lie impassive on 

 the sandy shore, which is strewed with broken coral frag- 

 ments, detached by wave-action from the neighbouring 

 reef, and riddled with the burrows of nimble Ocypods {0. 

 macrocera and 0. ceratojihthalma.) The habits of the latter 

 species of crustacean are well described by Sir J. Emerson 

 Tennent, who writes ^ : — 



'• The ocypode burrows in the dry soil, making deep excava- 

 tions, bringing up literally armf uls of sand, which, with a spring 

 in the air, and employing its other limbs, it jerks far from its 

 burrows, distributing it in a circle to the distance of several feet. 

 So inconvenient are the operations of these industrious pests 

 that men are kept constantly employed at Colombo in filling up 

 the holes formed by them on the surface of the Q-alle face. This, 

 the only equestrian promenade of the capital, is so infested by 

 these active little creatures that accidents often occur through 

 horses stumbhng in their troublesome excavations." 



Not far from the north end of the town of Tuticorin, 

 on the sandy shore, are the kilns, in which corals, coarse 

 mollusc shells [Ostrcea, Venus, Cardhim, &c.), and melobesian 

 nodules (calcareous algse) are burned and converted into 

 chundm,^ i.e., prepared lime used for building purposes, and 

 by natives for chewing with betel. A native informs me 

 that in the Bombay and Bengal Presidencies and in the 

 North- Western Provinces pearls are bought by wealthy 

 natives to be used instead of chundm with the betel. In 

 India relations and friends put some rice into the mouth of 

 the dead before cremation, but in China seed pearls are used 

 for the same purpose. 



During my visit to Tuticorin in 1887, I used to watch, 

 almost daily, grand, massive blocks of Pontes, Astrcea and 

 various species of other stony coral genera, being brought in 

 canoes from the reefs and thrown into the ground to form 

 the foundation of the new cotton mills, which, in consequence, 

 bear the name of the Coral Mills. 



Lecturing at the Eoyal Institution ^ on the " Structure, 

 Origin, and Distribution of Coral Reefs and Islands," 



1 Sketches of the Natural History of Ceylon, 1861. 



^ The familiar house frog {Rhacophorns maciilatiis) of Madras is popularly 

 known as the " chun&m frog " from its habit of sticking on to the chun&ia 

 walls of dwelling houses. 



3 Friday, March 16, 1888. 



