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 
may be 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 Holothurim, 
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. 
Pentaceros ? 
