species are to be found moored by their coarse filamentous byssus, 

 generally to such rocks or other submarine bodies as are exposed at 

 some periods of the tide, where tides exist, and covered by the sea at 

 high water. Mr. G. B. Sowerby does not think' that, after being once 

 attached, they habitually disengage themselves, though it appears to 

 him probable that, when disengaged by the force of the sea, they may 

 live for some time without being in any manner affixed. 



M. Desbayes, in the last edition of Lamarck, thus describes the 

 animal : Oval, elongated ; the lobes of the mantle simple or fringed, 

 united posteriorly in a single point so as to form an anal siphon; 

 mouth rather large, furnished with two pairs of soft palps, which are 

 pointed and fixed by their summit only. Foot slender, cylindraceous, 

 carrying at its base and posteriorly to it a silky byssus ; abdominal 

 mass moderate, and on each side a pah* of branchite nearly equal ; two 

 adductor muscles ; the one anterior and very small, the orher posterior, 

 large, and rounded. 



O Q X 



Gland of the byssus, mantle, oviduct, &c. of Jfytitus cdtilis. Garner. 



A, right lobe of the mantle ; D, rectum ; G, branchice ; II, foot ; J, posterior 

 muscle ; L, superior tube ; O, heart ; P, ventricle ; Q, auricle ; X, pericar- 

 dium ; 6, tentacles ; rf, byssus ; f, gland of the byssus ; g, retractile muscle of 

 the foot ; A, valves of the mantle ; ', oviduct ; i, orifice of the excretory organ 

 t, Internal ditto. 



The species are numerous, and most of them are used as food ; but 

 they should be eaten with caution, for serious illness and even death 

 have ensued from a meal made on some of them. The byssus, or beard, 

 aa it ia popularly called, should be carefully cleared away, and they 

 should be particularly avoided when cholera is about, or even when 

 diarrhoea is prevalent 



Captain I'. P. King, R.N. ('Voyages of the* Adventure and Beagle,' 

 vol. i.), mentions the Choro (Mytilus Choros of Molina) as among those 

 shell-fish of the island of Chiloe which are more particularly deserving 

 of notice. Speaking of this large muscle, Captain King says, " Molina 

 has described the Choro of Conception, which is not at all different 

 from that of Cbilo'e. It ia often found seven or eight inches long. 

 The fish is aa large as a goose's egg, and of a very rich flavour; there 

 are two kinds, one of a dark-brown and the other of a yellow colour; 

 but the last is most esteemed. There is also another sort, much larger 

 than the Choro, yet equally delicate and good, the fish of which is as 

 large as a swan's egg : it is called Cholgua ; but as the shells seem to 

 be of the same species, I think the distinction can only be owing to 

 size. In Febres's ' Dictionary of the Chileno Language,' the worJ 

 Cholchua is rendered into Spanish by ' Cascarade Choros Blancos,' 01 

 ' Shell of the White Muscle.' Cholhua, or Cholgua (the letters g and 

 A are indiscriminately used), must be a corruption; for it is now usec 

 in ChiMe to distinguish the large from the small choros. The manner 

 in which the natives of these islands, both Indians and descendants o: 

 foreigners, cook shell-fish is very similar to that used for baking in the 

 South Sea Islands and on some parts of the coast of New Holland 

 A hole is dug in the ground, in which large smooth stones are laid 

 and upon them a fire is kindled. When they are sufficiently heatec 

 the ashes are cleared away, and shell-fish are heaped upon the stones 

 nd covered first with leaves or straw and then with earth. The fish 

 thm baked are exceedingly tender and good ; and this mode of cooking 



Ova of Mi/li/us cilulis. (l-18th inch focus.) 



Mtj'.iltix ejitlis. 



a, detached valve ; the animal in situ with byssus ; the mantle slightly con- 

 tracted ; 4, valves conjoined ; animal as seen when the shell is partly forced 

 open, with byssus. 



The Common Edible Muscle is found in extensive beds below low- 

 water mark, and also at a greater depth. Rocks and stones between 

 high-water and low-water marks are also covered with them. We once 

 saw a lobster, which is now, we believe, in one of our museums, with 

 its shell coated with them. The species is used largely as an article 

 of food, and is considered rich and sapid by many ; but it entirely 

 disagrees with some constitutions, and, besides other derangements, 

 has been known to cause blotches, swellings, &c. Some cases are 

 recorded where these and other affections have been produced by 

 eating these muscles, whilst some who have partaken from the same 

 dish have escaped all evil consequences. These derangements have 

 been attributed by some to the byssus, by others to the Pea-Crab 

 [PIJJNOTHERIANS], a little crustacean which shelters itself, especially at 

 particular seasons, in the shell of the muscle, and by others again to 

 the muscle itself being in an unwholesome state or out of season. 

 There can be little doubt that the muscle, like the oyster, and indeed 

 like most other edible animals, is comparatively unfit for the food of 

 man at certain periods; but that the Pea-Crab has anything to do 

 per se with the poisonous qualities of these esculents is denied by 

 all who have written on the subject. When any symptoms of derange- 

 ment occur after eating muscles an emetic should be taken and after- 

 wards a dose of castor-oil. Cases of this kind are however rare. 

 Pennant remarks, that for one who is affected by eating muscles a 

 hundred remain uninjured. 



No anatomical investigation into the condition of such specimens 

 as prove injurious, nor chemical analysis of their composition, has 



