illustrations. 
IX 
Natural history or the American lobster — Continued. Page. 
Fig. 35. Cephalothorax of lobster in first stage when under stimulus of pressure, drawn im- 
mediately after reddening through expansion of chromatophores 330 
36. Cephalothorax of the same individual 10 minutes after release from pressure, and 
after paling from contraction of chromatophores 330 
37, 38, and 39. Parts of seta; from cheliped of larval lobster showing different degrees of 
reduction from typical plumose type 333 
40. Swimming attitudes of young lobsters in the first free stages 335 
41. Second larva, or second swimming stage of lobster 337 
42. Third larva, or third swimming stage of lobster 339 
Anatomy and physiology of the wing-shell Atrina rjgida: 
Fig. 1. The shell 413 
2. Diagrammatic cross section of the body anterior to the adductor muscle 415 
3. Transverse section of gill 420 
4. Diagrammatic drawing of a bit of the gill 421 
5. Transverse section of a filament 422 
6. Drawing of kidney in position 430 
7. Bodies excreted from the kidney 431 
8. Section of the glandular portion of the kidney 431 
9. Drawing of the digestive system in position 432 
10. Drawing of the cerebral and pedal ganglia with their connectives 433 
11. Drawing of the visceral ganglia 433 
12. Drawing to show distribution of mantle nerves 434 
13. Drawing of transverse section of one lobe of otocyst 435 
14. Reconstruction of the compound otocyst from a series of sections 435 
15. Drawing of transverse section of the foot showing the position of the otocyst 436 
