CEllITHIUM. 133 



exhibiting a certain delicacy of colour and design, and are 

 probably carnivorous ; the latter, which inhabit fresh or 

 brackish water at the mouths of estuaries, or live in swamps 

 among the roots of trees, are of a lighter description, and 

 mostly of a uniform dull colour, covered with a horny epi- 

 dermis. These are oviparous, and may be often found 

 suspended from the branches of trees by means of silken 

 threads, which the creature spins readily after the manner of 

 the silkworm. This pecuharity, first observed in the West 

 Indies by the Eev. Lansdowne Guilding, has also been 

 described by Dr. Trail, in a journal of natural history 

 recently published at Singapore, as also by Mr. Adams, 

 during his visit to Borneo. 



Mangrove-swamps, and the mouths of rivers in Singapore 

 and Borneo, are favourite resorts of the Cerithia, where 

 they may be seen at one time crawling on the stones and 

 leaves, at another suspended by glutinous threads to the 

 boughs and roots of the mangroves. When about to close 

 his doors during the cold season, the inhabitant carefully 

 contracts himself into his shell, and brings his round horny 

 and semitransparent operculum, or door, to fit closely into 

 the aperture, having previously fixed sixty or seventy glassy, 

 transparent, and glutinous threads about the outer or right 



