FIGURE 10 in Biology, morphology and taxonomy of a snail-feeding leech from North Carolina, USA, provisionally identified as Helobdella lineata (Verrill, 1874) (Glossiphoniidae): First evidence for extra-oral digestion in the Hirudinea

FIGURE 10. Evidence that the neck region of H. lineata is capable of extending and swelling (see section on feeding biology). A, proboscis everted; B–D, proboscis at rest, i.e. not everted. A (HL-9D), neck region narrows (white arrow) when proboscis is extended; B (HL-15A), annulation of the neck region at rest is more subdivided than annuli in mid-body region; C (HL-13A), ventral nerve cord (blue) between ganglia VIII–IX and IX–X is characteristically sinuous (black arrow) when individual is at rest. D (HL-13A), single salivary ductules are sinuous (black arrow) within the proboscis when individual is at rest. Abbreviations: co, circumpharyngeal commissure (brain); sd, single salivary ductule (brown); sb, salivary bundle (brown). Scale bar: 10 mm.