MYTILID.*. 



low 



Shell of Xytilu, alula. 



m, Talren elated, with bjMU ; ft, external view of one of the valves ; e, inter- 

 nal riew, holni the muteolar impreuloni. 



revealed the cause of the disorder; but as such casualties result 

 mostly in summer, it is prolwble that some natural change is takfbg 

 place in the animal, which renders it at that season unfit for food. It 

 would therefore be prudent to use it only in the winter months. The 

 idea that it is owing to the fish having absorbed copper is quite 

 unfounded. The application of heat in cooking does not destroy the 

 noxious property, as it does that of many vegetable poisons, for those 

 which are dressed are as hurtful as those eaten raw. Neither does 

 decay seem to be the source of the deleterious principle, since bad 

 effect* follow the use of those which ore quite fresh ; nor does decay 

 decompose the poison, though most animal poisons are destroyed by 

 putrefaction, for fatal cases have ensued from the eating of decaying 

 muscles. The consequences have been imputed to idiosyncrasy in 

 those who eat the muscles ; but this is obviously inadequate to explain 

 the circti instances, since in most of the instances every person (amount- 

 ing in one case to thirty individuals) who tasted them suffered ; and 

 even cat* and dogs, as well as human beings, died from eating them. 

 The morbid symptoms vary, and in some of the cases are connected 

 with inflammation of the stomach and intestines. " Two affections of 

 this kind have been noticed ; one is an eruptive disease, resembling 

 nettle-rash, and accompanied with violent asthma ; the other a coma- 

 tow, or paralytic disorder, of a very peculiar description. The 

 symptoms have usually commenced between one and two hours after 

 eating, and rapidly attained their greatest intensity. The first 

 symptoms were like those of violent catarrh, swelling and itching of 

 the eyelid*, and generally nettle-rash followed; and the eruption 

 afterwards gave place to symptoms of the most urgent asthma. The 

 swelling is not always confined to the eyelids, but has usually extended 

 over the whole face. In several eases the eruption was preceded by 

 asthma, lividity of the face, insensibility, and convulsive movements 



of the extremities ; in others nausea and vomiting, followed by heat 

 and constriction of the mouth and throat ; difficulty of swallowing 

 and speaking freely; numbness about the mouth, gradually extending 

 to the arms, with great debility of the limbs." The abdomen is often 

 affected with pain, increased on pressure ; the functions of the kidneys 

 disturWd, but generally increased ; the bowels sometimes obstinately 

 constipated. Epileptic symptoms, or delirium, convulsions, and coma, 

 have appeared in the greater number of fatal cases, rather than inflam- 

 matory action. 



Emetics, such as sulphate of zinc, which acts quickly, have been of 

 service ; but ether seems the most effectual means of relieving the 

 difficulty of breathing and the other nervous symptoms. 



Particular localities are celebrated as producing this muscle in per- 

 fection. " Ne fraudentur gloria sua littora, exclaims Pennant, 

 " I must in justice to Lancashire add, that the finest muscles are 

 those called Hambleton Hookers, from a village in that county. 

 They are taken out of the sea and placed in the rivtr Weir, within 

 reach of the tide, where they grow very fat and delicious." In ' The 

 Forme of Cury ' (1390) is a receipt for dressing ' HuakeU in Browet,' 

 and also one for making ' Cawdel of Muskels.' 



Small or seed pearls frequently occur in this species, and some yean 

 ago these were employed for medical purpose*. 



* Xylili with the shell striated longitudinally. 



if. Maycllaniciu. Shell oblong ; whitish below, purple violet above, 

 with long thick undulated furrows ; the umboues acute, and not much 

 curved. Length varying, generally from 4 to 5 inches. 



It is found in the Straits of Magalhaens, ChilcSe, 4c. 



The flesh is well-flavoured and nutritious. The shells of old indi- 

 viduals, when polished, are brilliant, with a nacreous deep purple 

 tinged with violet 



tfylilia JfagfllanicM, attached to a rock by 1U bvMX. 



It is not improbable that this species ministered in a degree to the 

 woful wants of Byron and his wretched companions after the wreck 

 of the Wager. " Having thus established," gays that officer, " some 

 sort of settlement, we bad the more leisure to look about us, . 

 make our researches with greater accuracy than wo had before, after 

 such supplies as the most desolate coasts are seldom unfurnished with. 

 Accordingly we soon provided ourselves with some sea-fowl, and found 

 limpet*, muscles, and other shell-fish in tolerable abundance ; but this 

 rummaging of the shore was now become extremely irksome to those 

 who had any feeling, by the bodies of our drowned people thrown 

 among the rocks, some of which were hideous spectacles, from the 

 mangled condition they were in by the violent surf that drove in upon 

 the coast. These horrors were overcome by the distresses of our 

 people, who were even glad of the occasion of killing the gallinazo 

 (the carrion crow of that country) while preying on these carcasses, in 

 order to make a meal of them." 



Hero may bo introduced the Sfytilui polymoiyhut of Pallas, Qmelin, 

 and others, thus characterised as a genus by Dr. Vanbeueden, under 

 the name of 



Drrittcna. Mantle entirely shut, presenting three apertures, one of 

 which is furnished with a siphon. Anterior extremity of the body 

 bifurcated and lodging in the middle of the division the transverse 

 anterior muscle. Abdomen depressed; extremities of the . bronchia 

 floating in their posterior half. 



The shell is regular, equivalve, inequilateral, umbo with a septum 

 in it* interior. Three muscular impressions, the middle one unique 

 and linear. 



I ir. Vanbeneden thinks that the organ of the byssus, which he 

 designates, after 1'oli, by the name of ' languettc,' has been erroneously 



