60 



cular filaments ; anal tube cylindric, externally visible ; bran- 

 chial leaflets equal on each side. (Forbes.) 

 Shell ; nearly equivalve, inequilateral, auriculated, gaping on one 

 side ; umboes divaricate, their internal areas being inclined 

 outwards ; hinge toothless, but sometimes indistinctly crenulated 

 on either side ; ligament partially external, contained in a cen- 

 tral triangular pit. 



One of the most obvious peculiarities of the Lima is that their shell is 

 of a pure transparent-white substance, sometimes, however, covered with 

 a brown epidermis ; and the animal is peculiar in having the mantle fringed 

 with a multitude of long tentacular filaments, which are sometimes of a 

 beautiful scarlet-tinged orange-colour. In form the shell has a close re- 

 semblance to Pecten, but the umboes have a tendency to project outwards, 

 and to form, in both valves, an inner area. The species are mostly cha- 

 racterized by a scaly sculpture, and gape, more or less, on the anterior side 

 for the passage of a byssus, by the aid of which it weaves together frag- 

 ments of coral, and builds a kind of nest for itself.* Three species are 

 British. 



1. angulata, Sow. 



2. arcuata, id. 



3. Basilanica, Ad. 8f R. 



4. bullata, Bom. 



5. Caribbasa, D'Orb. 



6. Curningii, Sow. 



7. dentata, id. 



8. excavata, Chemn. 



Species. 



9. fasciata, Linn. 



10. fragilis, Chemn. 



11. hians, Gmel. 



12. inflata, Chemn. 



13. Loacombii, Leach. 



14. inulticostata, Soto. 



15. orientalis, Ad. $r R. 



16. paucicostata, Soto. 



17. rotundata, id. 



18. Sarsii, Loven. 



19. scabra, Born. 



20. squamosa, Lam. 



21. subauriculata, Mont. 



22. tenera, Chemn. 



23. ventricosa, Soto. 



24. vulgaris, Link. 



* Speaking of the Lima hians, Dr. Landsborough says : — " The coral nest is curiously con- 

 structed, and remarkably well fitted to be a sate residence for this beautiful animal. The fragile 

 shell does uot nearly cover the mollusk, the most delicate part of it, a beautiful orange friuge- 

 work, beiug altogether outside of the shell. It is not contented with hiding itself among the 

 loose coral, for the first rude wave might lay it naked and bare. It becomes a marine mason, 

 and builds a house or nest. It chooses to dwell in a coral grotto ; but in constructing this grotto 

 it shows that it is not only a mason but a rope-spinner, and a tapestry-weaver, and a plasterer. 

 Wheu the Lima is taken out of its nest, and put iuto a jar of sea- water, it is one of the most beau- 

 tiful marine animals you can look upon. The shell is beautiful ; the body of the animal within 

 is beautiful ; and the orange fringe-work outside the shell is highly ornamental. Instead of 

 being sluggish, it swims about with great vigour. Its mode of swimming is the same as that of 

 the scallop. It opens its valve, and suddenly shutting them expels the water, so that it is im- 

 pelled onwards or upwards ; and when the impulse thus given is spent, it repeats the operation, 

 and thus moves on by a succession of jumps. When moving through the water in this way the 

 reddish fringe-work is like the tail of a fiery comet." — Excursions to Arran, p. 319. 



