476 T. H. MORGAN. 



Fig. 72, a b. — Disagreement between surface line (a) and septa (b). 



Fig. 73. — Dissection of a compound metamere. Septa do not agree with 

 surface lines. 



Fig. 74, a b. — Vas deferens doubled on right side. L. terrestris. 



Figs. 75 — 78. — Abnormal arrangement of metameres in young worms at 

 time of emergence from coccoon. Fig. 75, category i; Fig. 76, category vii; 

 Fig. 77, category viii ; Fig. 78, category x (PI. 40). 



PLATE 43. 



Figs. 79 — 81. — Regenerating posterior ends of the body of L. foetidus, 

 See text for description. 

 Figs. 82 — 85. — Abnormal arrangement of the metameres in Amphinome. 



Figs. 86 — 88. — Abnormal arrangements of the rings of leeches (Macrob- 

 dilla decora). 



Fig. 89, a b c. — Compound metamere 5 — f in abdomen of locust. 

 Figs. 90 — 95.— Abnormal arrangements of the rings of the lobster, 

 Homarus americanus. 



Fig. 96. — Nine segments of the arm of a brittle-star (Opbiuridea) from 

 Jamaica, as seen from below. Every fourth segment is a pigmented colour-ring. 



Fig. 97. — Nine segments of another individual, showing the middle pig- 

 mented ring broken. 



Fig. 98. — To show a further separation of colour-rings. 



