374 



ScAi.Y Pinna. - 



-JIOLLUSCA.- 



-AVICULID.E. 



The young bhells are very thin aud brittle, but some 

 of tlie species, when they reach their full size, are thick 

 and solid, and attain a length of upwards of two feet. 

 The nacreous lining of the interior is thin and scarcely 

 extends half-way from the beak. The colour of this 

 internal pearly coat is usually of a reddish hue, and 

 frequently pearls of a considerable size are found in the 

 shells, partaking of the same tint, or that of amber. 

 Specimens may be seen in the collection of the British 

 Museum. Some of the Pinnas are used as articles of 

 food ; while others are valued for the powerful, silky 

 byssiis which, it has been mentioned, they possess. 



" THE SCALY PINNA {Pinna squamosa)— V\-A\.<i 11, fig. 

 20 — has long been known for the silky material which it 

 alfords, and whicli has been woven into various articles 

 of dress. '' This silk," says Dr. Johnston, " is the byssus, 

 cr rather the cable of the animal, by means of which it 

 is moored to the rocks, in the same manner that our 

 coiaraon mussel is. In a crude state the silk is called 

 lutapenna: the threads are extremely fine, of a perfect 

 equalness in diameter through their whole length, and 

 of great strength. It is cleansed from its impurities 

 by washing in soap and water, drying, and rubbing 

 witli the hands. It is then passed through combs of 

 bone, and afterwards, for finer pur|)oses, tiirough iron 

 combs or cords, so tliat a pound of the coarse filaments 

 is usually reduced to about three ounces of fine thread. 

 When mixed with about one-third of real silk, it is 

 spun on the distaff, and knit into gloves, caps, stock- 

 ings, vests, &o., forming a stulf of a beautiful brownish- 

 yellow colour (resembling tlie burnished golden hue on 

 the back of certain flies and beetles), but very liable to 

 be moth-eaten, and requiring to be wrapped in fine 

 iinen. A pair of gloves costs on the spot about six 

 shillings, and a pair of .stockings eleven ; but its sale is 

 not very extensive, and the manufacture is peculiar to 

 Toronto." Specimens of the byssus, and gloves made 

 from it, may be seen in the collection of the British 

 Museum. It has long been known that a little crab 

 infests the mantle or gills of this same Pinna, and in- 

 deed the common mussel of our own shores also. The 

 fact was known to the ancient naturalists, who, as Dr. 

 Johnston observes, " never left an observation to stand, 

 like truth, all naked, but ever clothed it with some 

 pretty vestment." They believed that this little crab 

 (belonging to the genus Pinnotheres) formed a close alli- 

 ance with the shell-fish, and acted the part of a guar- 

 dian to its blind host. The story is told by Pliny, and 

 is thus translated by Dr. Holland : — " The Nacre, also 

 called Pinna, is of the kind of shell-fishes. It is alwaies 

 found and caught in muddie places, but never without 

 a companion, which they call Pinnoter, orPinnophylax. 

 And it is no other but a little shrimpe, or, in some 

 places, the smallest crab, which beareth the Nacre 

 compauie, and waites upon liim for to get some vic- 

 tuals. The nature of the Nacre is to gape wide, and 

 showeth unto the little fishes her seelie body, without 

 any eie at all. They come leaping by and by close 

 unto her ; and seeing they have good leave, grow so 

 hardy and bold as to skip into her shel and fill it ful. 

 The shrimp lying in spiall, seeing this good time and 

 oiiportunitie, giveth token thereof to the Nacre, secretly 

 with a little pinch. She hath no sooner this signall 



but she shuts her mouth, and whatsoever was within 

 crushes and kills it presently ; and then she divides 

 the bootie with the little crab or shrimp, her sentinel 

 and companion." The family Pinnadce isa very natural 

 one, and contains only two genera — Pinna, distinguished 

 by having the shell elongated and marked with a longi- 

 tudinal crack filled with cartilage in the middle of 

 each valve ; and Alrina, which has a shorter shell and 

 no such crack. 



Family— A VICULID^ {The Wing-shells). 



The shells are inequivalve, very oblique in most in- 

 stances, resting on the right valve, which is the smaller, 

 and wdiich has a notch in the front margin for the pas- 

 sage of the byssus. The ligament is marginal, and the 

 cartilage is contained in one or several grooves, the 

 hinge being without teeth, or obscurely dentated. The 

 beaks are anterior and eared, tlie posterior ear wing- 

 like. The outer surface of the valves is foliated, with 

 an indistinct epidermis, and the interior is highly 

 nacred or pearly. There are several genera, as Malleus, 

 the Hammer-oyster; ^r/cufa, the Wing-shell ; Mar- 

 garitijihora, the Pearl-oyster; Perna, and Crenatula— 

 but we have only space for a notice of the Pearl-oyster. 



Genus Margaritiphora {the Pearl-oyster). — This 

 genus has a less oblique shell than most of the family, 

 and the valves are flatter and nearly equal. They are 

 somewhat orbicular in shape, and the hinge margin is 

 not produced posteriorly into ears. The hinge is with- 

 out teeth, and the ligament is external and dilated in 

 the middle. The external surface of the shell is squa- 

 mose, and the interior is of a pearly lustre. The Pearl- 

 oysters are famed for their production of the beautiful 

 Oriental pearl, and the substance, so much used in the 

 arts and manufactures, called " mother of pearl." The 

 shells are found at Ceylon, the Persian Gulf, Mada- 

 gascar, the Swan Kiver, Panama, and other parts of 

 the coast of America, and are usually procured from 

 about twelve fatlioms water. Pearls, being amongst 

 the most beautiful ornaments for female attire, have for 

 a very long time been highly prized, and the love for 

 their use has often called down stern denunciations, 

 from satirists and morahsts, of female vanity. " Pearls 

 of great price" have been eagerly souglit after by man- 

 kind from the earliest ages. The Romans had an inor- 

 dinate love for ornamenting themselves with pearls. 

 Pliny tells us that Lollia Paulina ("late wife, and after 

 widow, to Cains Caligifla, the emperor,") used to wear 

 such a quantity of pearls and emeralds about her person, 

 tliat the value was rated, according to her own estima- 

 tion, at 400,000 sestertii. " I have seen her," he says, 

 " so beset and bedeckt all over with hemeraulds and 

 pearls, disposed in rows, ranks, and courses one by 

 another; round about the attire of her head, her cowle, 

 her borders, her peruk of hair, her bond grace and 

 ohaplet ; at her eares pendant, about her neck in a car- 

 canet, upon her wrist in bracelets, and on her fingers 

 in rings ; that she glittered and shone again like the sun 

 as she went." In those days the most extravagant 

 prices were given for pearls. Julius Caesar, we are 

 told, presented Servilia, the mother of JI. Brutus, witli 

 a pearl worth £48,417 ; and the celebrated Cleopatra, 



