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Bevalet, M. ch.
Emerton, J. H.
Holder, Charles Freder...
Fischer, E. N.
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Wellfleet quahauging fleet at their moorings in Duck Creek. Practically all these boats are equipped with gasoline engines, a common type being power cat boats without masts
Principal enemy of the adult quahaug is the common winkle or cockle (Lunatia duplicata or heros), pictured at the right and left in the illustration. In the corners are quahaug shells, through which a clean countersunk hole has been bored by this mollusk at the umbo. In the center is a starfish, the great pest of the oyster beds, and on rare occasions an enemy of the quahaugs.
Photograph taken from a model in the Museum of Natural History in New York. The different portions of the anatomy are indicated by the labels. The sympol A. A. and P. A. refer to the anterior and posterior adductor muscles, which hold the two valves of the shell together. The posterior part of the animal is represented by the siphon, which consists of two parts, an incurrent and an excurrent, through which the water enters and leaves the quahaug in the directions indicated by the arrows. In the mantle chamber the food is filtered from the water by the gills, which are here shown cut off near their base.
Growth of a quahaug in the raft boxes, Monomoy Point, from one and one-half to five and one-half years old, is shown with the corresponding increase in volume. Starting with 1 bushel of one and one-half-year-old quahaugs, there would result at the age of five and one-half years approximately 19 bushels. The figures on the left give the size of the quahaug...; those on the right represent the volume in bushels corresponding to the various years.
Map showing the distribution of the quahaug in Massachusetts. The black areas indicate ground where quahaugs are found.
1 millimeter in size, half buried in the sand. The animal is feeding, water passing in and out of the extended siphon, as shown by the arrows.
1 millimeter (1/25 inch) in length, attached to sand grains by the byssus (B). The ssipphon (S) consists of two parts, an incurrent encircle dby twelve tentacles, through which the water enters the mantle chamber of the animal, and an excurrent with four tentacles and filmy telescopic tube through which the water passes out of the mantle cavity. The byssus areises from a gland on the under side of the foot (ft).
Fig.15.--Ciliated gastrula, ten hours after fecundation. The embryo Can now swim through the water by means of hairlike cilia. The larger cells have become invaginated.
Fig.16.--Trochosphere stage, twelve to fourteen hours after fecundation. The body has elongated and the cilia are now confined to the front end. The opening of the primitive mouth (pm) cn be seen on the lower side, while above is a slight indentation corresponding to the eginning of the shell gland (sg).
Fig.17.--Formation of the shell, which arises at two symmetrical points of calcification, right and left of the median line, and gradually envelops the animal.
Fig.18.--Early veliger swimmer with velum extended from the shell, about thirty-six hours after fecundation. aa, anterior adductor muscle, pa, posterior adductor muscle, s, stomach, a, anus, mt, mouth, v, velum.
Fig.19.--Veliger slightly older than shown in Fig.18. The intesting (i) has elongated, and the liver (l) is more prominent.
Fig.1.--Mature egg ready for union with male cell.
Fig.2.--Spermatozoa (male cells). Note length of tail and shape of head. No attempts were made to study the minute anatomy.
Fig.3.--Egg, twenty-five minutes after fecundation, showing the two polar cells (pc) and the faintly developed yolk love.
Fig.4.--Egg just previous to the first cleavage, showing large yolk lobe.
Fig.5.--The two-celled stage at the completion of the first cleavage, fifty minutes after fecundation. The larger cell contains the yolk lobe.
Figs. 6,7,8,9.--This series illustrates the process of cleavage in the egg during the change from the two-celled to the four-celled stage.
Fig.10.--The four-celled stage, one hundred and ten munites after fecundation. Side view.
Figs. 11,12.--The eight-celled stage, one hundred and forty-five minutes after fecundation.
Fig.13.--The sixteen-celled stae, one hundred and eighty-five munites after fecundation. Side view.
Fig.1--Leftsecond periopod from anterior or upper side, partly dissected to show the relations of muscles and tendons in the principal segments; hinges (h) and nerves (n1 and n2) are indicated; and exterior and flexor muscles (ex, fl) are numbered to correspond to segments of origin. Fig.2--Shell of right toothed forceps in sectional view from above, the show tendons crossing distal joints. s h, lower sliding hinge, form inside; mb, interarticular membrane (dotted line marking position of former tendon pocket)
Left crusher claw of lobster, partly dissected from upper side, to show relations of muscles, nerves, blood vessels, and skin with principal branches of claw arteries and nerves laid bare. art, large artery which supplies both muscles of claw, and breaks into a regular system of branches in fine meat of tips; n (1), n (2), posterior and anterior nerve trunks supplying, respectively, the exterior (Ex6) and thumb, and the flexor (fl6) and index
Left second to fifth periopods or slender legs of adult lobster from anterior side, showing numbered segments of permanent limb, distribution of sensory tufts (s s), gills (pb) and gill separators (ep), arrangement of ball and socket basal hinges, median ball (h, b), and peripheral socket (h, s) tendons of basal joints (t fl. I aand t ex. I), and cleaning pick and brush (cl. br) of last leg. Star in figure 4 marks position of exopodite or outer swimming branch of thoracic limb, shed at fourth stage
Transverse section of body of female lobster in plane of gastric mill..... ad. m. abductor mandibuli muscle; art, branchio-cardiac vessel; arth. br., arthrobranch; br. cav., branchal cavity; brs, branchiostegite; d. g. g. duct of gastric gland; fl. g. ch. based flexor of great chelipad; g. g. gastric gland; int. s. internal skeleton in roof of sternal sinus; n. (x), main nerve of great cheliped; p. g. m. i., first division of posterior gastric muscle; p. br., pleurobranch; Podo br., posobranch; i. ad. m., tendon of abductor mandibull muscle; th. fl, floor of thoracic cavity
Half section of lobster cut in median plane to illustrate general anatomy. From soft shell female, 6 1/2 inches long, slightly favored in head to show nervous system. Esophageal and gastric ganglion (the latter below reference line to anterior gastric muscle) and anterior visceral and median nerves are shown. Muscle marked levator abdominis (thoracico-abdominis) originates far forward in the thorax and joins enveloping muscles of the flexor system of abdomen. Note that abdominal sternal spines are much longer than in sexually mature animals
Abalone shells and pearls. Black abalone (Haliotis cracherodii)-1; Red abalone (H. rufescens-2; Green abalone (H. fulgens)-3; Common boring mollusc (Pholadidea parva) which causes the formation of blister pearls-4; Another mollusc (Adula stylina) which bores into the heavy rim of the abalone shell-5; Exterior of the abalone shell showing the aperture of the bore of the parasitic mollusc-6; Abalone pearl-7
Mya arenaria. Ten camera outlines of shells varying in length from 0.4 mm to 7.5 mm. They are intended to illustrate the change from a rounded outline in smaller individuals to the elongated condition of older forms. There is at first a more rapid posterior, and subsequently a more rapid anterior, growth of shell, which causes the relative position of the umbo to shift forward, and then back to a position midway between the two extremities of the shell
Large Baroque Pearls : irregular nacreous growths, with more or less beauty of luster and color. (Rear)
Nos.1,7,8,11, Showing a twisted structure; NO.12, with a row of protuberances; Nos.2,3,4,6,10, More regular; NO.9, immsnse mass of hinge-matter, salmon-pink in color
Dipsas plicatus, Interior and Exterior, Interior containing tinfoil figures of Buddha.
Four inches long. Pearl-coated figure of Buddha, obverse and reverse, showing concave depression ofiginally filled with tinfoil or wax ...from temples in Souchow, China
Valve of Unio in its Natural State, and the same with 'blanks' cut out from it. Blanks as cut; three upper figures showing inside, three lower showing outside with or or less of the epidermis. The same ground but not 'centered' or polished. The same centered. i.e. with the central depression made, but not the holes. The same with the holes drilled complete. A dozen buttons, as fastened on card for sale
Salmon-Colored Pearl, weighing 14 1/2 pearl grains, lying loose where it was formed in a shell, from Linn Junction, Iowa. The pearl is nearly hemispherical, or 'button-shaped,' somewhat one sided, but perfect above. It occupied a depression at the posterior end of the right valve, and had caused a marked outgrowth or protuberance of the other valve.
A-Interior view of the right valve, with the pearl in place
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