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PROCEEDINGS OF THE NATIONAL MUSEUM 



Figure 34. — Proboscis and its parts: A, Sagittal section (semidiagrammatic) of proboscis 

 (BM, dotted line showing limits of buccal muscle and cartilage; BU, oral cavity; HY, 

 hyaline sheath or basal membrane of radula; JA, left jaw; LP, labial pads; OE, esophagus; 

 RA, radula or odontophore; RU, rudiment of radula). B, Dorsal (left) and anterior 

 (right) view of paired jaws (HY, hyaline sheath; JA, jaws). C, Outer view of right 

 jaw (PL, platelets; RU, rudiment of jaw). D, Dorsal view of exposed radula (HY, 

 hyaline sheath or basal membrane; RA, teeth of radula; RU, rudiment). E, Three 

 rows of radula teeth in their natural position (CE, centra! or rachidian tooth; DE, denticles 

 found on leading edge of all teeth; LA, lateral tooth; MI, inner marginal; MO, outer 

 marginal). 



