. Bulletin of the Natural History Museum Zoology. FOREGUT ANATOMY OF CRASSISPIRINE GASTROPODS 61. Fig. 6 Crassispira (Glossispira) harfordiana flucki (Brown & Pilsbry, 1913). A, semidiagrammatic longitudinal section of the foregut (salivary glands not shown); B, longitudinal section of the proboscis tip; C, section of the buccal mass, showing the opening of the radular sac. Crassispira (Glossispira) harfordiana flucki (Brown & Pilsbry, 1913) (Figs 4d, 6, 30e) Rhynchodeum and proboscis The rhynchostomal sphincter is small and slightly posteriorly situ- ated. The epithelium of the rhynch
. Bulletin of the Natural History Museum Zoology. FOREGUT ANATOMY OF CRASSISPIRINE GASTROPODS 61. Fig. 6 Crassispira (Glossispira) harfordiana flucki (Brown & Pilsbry, 1913). A, semidiagrammatic longitudinal section of the foregut (salivary glands not shown); B, longitudinal section of the proboscis tip; C, section of the buccal mass, showing the opening of the radular sac. Crassispira (Glossispira) harfordiana flucki (Brown & Pilsbry, 1913) (Figs 4d, 6, 30e) Rhynchodeum and proboscis The rhynchostomal sphincter is small and slightly posteriorly situ- ated. The epithelium of the rhynchodeum wall is glandular and that of the posterior rhynchodeal wall is not continuous with that of the proboscis wall. The proboscis tip is not inverted. The proboscis is very long and highly coiled (longer than the rhynchocoel and shown uncoiled in Fig. 6). The muscles of the proboscis wall are equally developed along its length, except at the very anterior. The anterior part of the proboscis from the mouth opening to the buccal mass is very thin (about mm compared to the proboscis length of about 5-6 mm) and highly folded. The proboscis tip is highly expanded to form a wineglass-shaped structure (Fig. 6, 30e). Closer to the tip, there is a septum with a small, circular sphincter surrounding the narrow opening. The septum delimits the sac-like enlargement of the buccal tube. The epithelium lining this is signifi- cantly taller than that of the rest of the tube, forming a low epithelial pad. At the base of the enlargement, there is a second small sphincter. Pieces of one, or possibly more, marginal teeth (fragmented during sectioning) were seen attached to the epithelium. The distance between the two sphincters corresponds to about one tooth length. It is possible, that the enlargement serves as a storage area for detached marginal teeth. There is no intermediate sphincter in the buccal tube. Buccal cavity and oesophagus The buccal mass is long (equivalent to about one quart
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