Figure 16. Diplomma serpentina (Stimpson, 1855). A, photograph of narcotized specimen taken in life; B, photograph of the same specimen as (A) before anaesthetization, showing natural shape of head; C, horizontal section through head, showing arrangement of outer portion of body-wall longitudinal musculature and its derivatives; D, horizontal section through head, showing arrangement of inner portion of body-wall longitudinal musculature contributing to proboscis insertion; E, sagittal section through head, showing cephalic retractor muscle fibre derived from inner portion of divided body-wall longitudinal muscle layer. A, B, E, UPLB-NHM 0489; C, D, ZIHU-1354. Abbreviations: AG, acidophilic cephalic gland; BG, basophilic cephalic gland; BR, brain; CO, cerebral organ; CR, cephalic retractor muscle; IL, inner portion of body-wall longitudinal musculature; OL, outer portion of body-wall longitudinal musculature; PI, proboscis insertion; PR, proboscis. Scale bars: A = 3 mm; C, D = 100 Mm; E = 50 Mm.