Figure 86. Bonito hook shanks, front: a, average type of shank (C. 2797) with well marked head, 95 mm. long, greatest width is 17 mm., tail width is 11 mm.; b, longer and wider shank (C. 2792) with large head and mesial edge ground down to comparatively large triangular surface (8), 103 mm. long, greatest width is 20 mm., tail width is 13 mm.; c, small shank (C. 2803) with small head formed from side section of hinge, 81 mm. long; greatest width is 13 mm., tail width is 9 mm.; d, long shank (C. 2794) with small head formed from side section of hinge, nacreous surface irregular at head end owing to irregularity of sides of hinge, 117 mm. long, greatest width is 16 mm., tail width is 11 mm.; e, long shank (C. 2937) from outer section through hinge, owing to shortness mesial edge not ground down to form triangular surface, 101 mm. long, greatest width is 15 mm., tail width is 10 mm. 1, head; 2, tail; 3, head point; 4, mesial edge; 5, head hole; 6, front natural nacreous surface; 7, expansion of sides formed by thickness of shell into antero-lateral surfaces which meet in mesial edge; 8, small traangular surface ground down on mesial edge to hold snood firmly; 9, tail grooves, made after fitting point.