MYTILID.E. 



MYTIUD.K. 



1010 



the Mediterranean and at the Antilles, when they arc found in stones 

 and niaaiwa of madrepore, and sometime*, but much more rarely, in 

 i thick tbclU. 



LiHioJomm Daetylut. 



a, Younft, with byMtui ; *, full-jtrown, inside of valve ; c, ditto, ouuidc of 

 valve ; rf, three (>ccinun in a raus of madrepore. 



Thia species is highly nutritious and well flavoured. Imprisoned 

 aa the animal is in the atone or madrepore, frequently with a very 

 small opening communicating with the sea, it must obtain a plentiful 

 supply of food, probably by means of the current* produced by the 

 animal, for the shells are always full and the animal plump. A stew 

 of these Lilkodomi i described by those who have partaken of it as 

 excellent 



With regard to the power of piercing rocks, stones, wood, &c., pos- 

 sessed by Lamellibranchiate animals, Mr. Garner, in a paper in the' 

 ' Philosophical Transactions,' observes that such piercing cannot in 

 every case take place by the mechanical nction of the valves, and he 

 instances those of Lithodomui as not at all adopted for such an action. 

 He also denies the possibility of the perforation being caused by a 

 solvent fluid secreted by the animal. [LiTiinrtiAiiin.K.] 



J'mna (Linn.) Animal elongated, rather thick, aubtriangular ; lobes 

 of the mantle united on the dorval border, separated throughout the 

 reit of their extent, ordinarily ciliated on the edges; foot slender, 

 conic, vermiform, carrying at its base a silky byssus ; mouth between 

 two lips, foliaceous within, very much elongated, and terminated by 

 two pairs of short palps, the two palps of one side soldered nearly 

 throughout their length ; two adductor muscle*, the anus terminating 

 behind the posterior one. (Desliayec.) 



Shell fibrous, horny, rather delicate, fragile, compressed, regular, 

 equi valve, longitudinal, triangular, pointed anteriorly, rounded or 

 truncated posteriorly ; anterior umbo but little distinct ; hinge linear, 

 atriate, toothless ; ligament marginal, a great portion of it internal, 

 very narrow and compact, occupying more than the anterior half of 

 the dorsal border of the shell, in a narrow and elongated gutter; 

 anterior muscular imprcmion very small and entirely in the angle, 

 posterior mtucular impression very large. (Rang.) 



Poli has given beautiful figure* of the animal, which he calls 

 diimtrra, and most elaborate details of its anatomy ; and to hi* great 

 work we refer the reader. There are no projecting siphons, and the 

 conic tongue like foot is employed by the animal to fix itself by the 

 byssns, which i not scanty and coarse, like that of the Mytili, but 

 long, fine, lustrous, and abundant ; so that, though it takes no dye, it 

 i* employed in manufactures in Italy. [Brsgus; COXCIIIPERA.] The 

 Pitnur approximate more especially to the Mytili, but the shell of 

 the former, with its straight utnbones and iU gaping opposite extre- 

 mity, strongly Iitini{iiilic th- in. There i a tendency in their shell 



to divide itself into laminae, and thus it approaches that of the 

 Malltacea. 



The species are generally found in deep water, but they have been 

 taken at depths ranging from the surface to seventeen fathoms ; moit 

 frequently on sandy bottoms, where they were moored by their by u, 

 and at no great distance from the shore. It is said that the animal 

 sometimes fixes itself by the aid of its byssus, and sometimes remove* 

 itself by the aid of iU foot Small c.-uaUceans, both brachy urous and 

 macruroiis, are sometimes found in their sheila. Species occur nearly 

 in all seas. Host of them are muricated when young with vaulted 

 or subtubular spines; but as they increase in age these are worn 

 down, and at last almost entirely disappear. We have had individuals 

 of the great Mediterranean Pinna before us, gradually increasing from 

 a very small size to nearly two feet in length. When specimens taken 

 at wide intervals were compared, the difference was so great that they 

 might easily have passed as distinct species, as indeed they have been 

 described by some authors. We have seen many pearls from tlii* 

 Pinna not ill-formed and of an amber colour, but none of any 

 considerable size. 



P. PlabtUum may be taken as an example of the genu*. ' About 30 

 recent niH 20 foril species of t'-i genus have been described. 





'SI 



finna Flakrllum, 



a, Young, with plne, and the brutu, natural tine ; t>, full-grown, innldc view 

 of valve, one-fifth natural ilie. 



Pouil Mytiliiltc. 



MytitHs. Mr. 0. B. Sowerby (' Genera ') states that the fosnil r pecies 

 with which he is acquainted are not numerous ; they occur however, 

 ho observes, in some of the beds below the chalk as well as in most 

 of those above it, but particularly in the crag. 



M. Dej-hayes, in bis Tables (1833), makes the number of fossil species 

 (tertiary) 15. M. Clnmnit:\i and M. etlulii he states to be both living 

 and foseil (tertiary). In the last edition of Lamarck (1836), he remarks 

 that Brocchi mentions a fossil shell to which the latter gives the name 

 of M. ,,lulii; but M. Deshayes does not believe that this fossil in 

 the analogue of M. edulii, Linn., but of another edible species very 

 common in the Mediterranean. Of fossil species he admits 9 only in 

 that work. Dr. Mantel) notices a species in the cliff between Brighton 

 and Rottingdean (diluvium) ; and another, .!/. liinrmlniu*, in the 

 Shftnklin csnd. Priifisfor Phillip" nots a .". ri'imittri from !!" infVii' r 



