. Bulletin of the Buffalo Society of Natural Sciences. Natural history -- New York (State); Natural history. 239 limestone, at Section 7; between the Trilobite beds ;in<l the vStrophalosia bed, in Avery's Creek, and on the Lake Shore (not uncommon). Note.— This species is, at Eighteen Mile Creek, almost entirely confined to the Encrinal limestone; but at Morse Creek, near Athol Spring's, it is common in the shales below the limestone. Class Pelecypoda. Goldfuss. (Lamellibranchiata. Blainville.) The Pelecypoda or Lamellibranchiata are marine or fresh-water mol- luscs, with a bivalve shell. T
. Bulletin of the Buffalo Society of Natural Sciences. Natural history -- New York (State); Natural history. 239 limestone, at Section 7; between the Trilobite beds ;in<l the vStrophalosia bed, in Avery's Creek, and on the Lake Shore (not uncommon). Note.— This species is, at Eighteen Mile Creek, almost entirely confined to the Encrinal limestone; but at Morse Creek, near Athol Spring's, it is common in the shales below the limestone. Class Pelecypoda. Goldfuss. (Lamellibranchiata. Blainville.) The Pelecypoda or Lamellibranchiata are marine or fresh-water mol- luscs, with a bivalve shell. The valves are complementary, and are in the majority of species of nearly similar outline and size. In each valve may be distinguished an initial point, or beak, around which the con- centric lines of growth mark the successive additions of shelly matter. The orientation of most shells is effected by holding them with the hinge line uppermost and the beaks pointing away from the observer. Thus placed, the upper border is the dorsal and the lower the ventral border. The end farthest awTay from the observer is the anterior end; that nearest, the posterior end. The valves are designated as the right and left valves, respectively. The articulation of the valves is commonly effected by the interlocking of teeth which are borne on the hinge or cardinal margin of the valves. They are very various, but they can usually be divided into the short, stout "cardinal teeth," which are situated under or near the beak, and the ridge-like lateral teeth. The opening of the valves is brought about by an elastic ligament stretched across the hinge from valve to valve, behind the beak, which acts when- ever the tension of the ad- ductor muscles, which close the valves, is relaxed. In many forms, an elastic, com- pressible cartilage, lodged in special grooves or pits, takes the place of the external ligament. The scars marking the attachment of the adductor or closing muscle, or muscles,
Size: 1798px × 1390px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectnaturalhistory, booky
