File:American malacological bulletin (1986) (17968295698).jpg

Title: American malacological bulletin
Identifier: americanmal4519861987amer (find matches)
Year: 1983 (1980s)
Authors: American Malacological Union
Subjects: Mollusks; Mollusks
Publisher: (Hattiesburg, Miss. ?) : (American Malacological Union)
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Biodiversity Heritage Library

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
SMITH: MARGARITIFERID STOMACH ANATOMY 15 of the esophagus are held in place by bands of attachment muscle (AM). The morphology of the stomach roof is in general agreement with other unionaceans (Graham, 1949; Purchon, 1958; Dinamani, 1967; Kat 1983a,b). The dorsal hood (DH) represents the most outstanding feature of the roof and is supported along with other portions of the left wall by attachment muscles (AM). Two prominent ridges (RS) are visi- ble through the roof. These ridges delimit the principal sorting areas of the interior surface of the roof. Internally (Fig. 2), the stomach floor, and in particular the lateral and posterior walls, are generally similar to other unionaceans. The gastric shield, not shown in the figure, shows no differnces from Anodonta spp. (Graham, 1949; Pur- chon, 1958) or Lamellidens sp. (Dinamani, 1967). The same is true for the posterior wall and the left wall, with some ex- ceptions depending upon the species investigated. The right embayment (RE) increases the area of the stomach. Ducts leading to the digestive diverticula originate from the anterior right and left walls (LAD, RD), and from a pocket in the left posterior wall (LPD) ventral and posterior to the dorsal hood (DH) and a shallow left embayment (LE). The right wall, par- ticularly the right sorting area (RSA), combining the "longitudinal ridge" (Purchon, 1958) and the "anterior fold" (Dinamani, 1967), showed considerable variation
Text Appearing After Image:
Fig. 2. Generalized interior and digestive duct systems of the margaritiferid stomach. Abbreviations: APR = anterior pedal retrac- tor muscle, ASA = anterior sorting area, DH = dorsal hood, LAD = left anterior duct system, LE = left embayment, LPD = left posterior duct system, MG = midgut and style sac, MT = minor typhlosole, OES = esophagus, PSA = posterior sorting area, RD = right duct system, RE = right embayment, RSA = right sorting area, T = major typhlosole, VE = ventral embayment. Horizontal field width = 13 mm.

Note About Images