396 



SHELLS. 



[Chap. XI. 



a few of those which exhibit striking peculiarities, or 

 which admit of the most common observation. 



Star Fish. — Very large species of Ophiuridce are to be 

 met with at Trincomalie, crawling busily about, and in- 

 sinuating their long serpentine arms into the irregulari- 

 ties and perforations in the rocks. To these they attach 

 themselves with such a firm grasp, especially when they 

 perceive that they have attracted attention, that it is 

 almost impossible to procure unmutilated specimens 

 without previously depriving them of life, or at least 

 modifying their muscular tenacity. The upper surface 

 is of a dark purple colour, and coarsely spined; the 

 arms of the largest specimens are more than a foot in 

 length, and very fragile. 



The star fishes, with immovable rays *, are by no 

 means rare ; many kinds are brought up in the nets, or 

 maybe extracted from the stomachs of the larger market 

 fish. One very large species 2 , figured by Joinville in 

 the manuscript volume in the library at the India House, 

 is not uncommon ; it has thick arms, from which and 

 the disc numerous large fleshy cirrhi of a bright crimson 

 colour project downwards, giving the creature a remark- 

 able aspect. No description of it, so far as I am aware, 

 has appeared in any systematic work on zoology. 



Sea Slugs. — There are a few species of Holothurice, 

 of which the trepang is the best known example. It is 

 largely collected in the Grulf of Manaar, and dried in the 

 sun to prepare it for export to China. A good descrip- 

 tion and figures of its varieties are still desiderata. 



Parasitic Worms. — Of these entozoa, the Filaria 

 medinensis, or Guinea-worm, which burrows in the 



1 Asterias, Linn. 



2 Pentaceros? 



