144 



BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



ABBREVIATIONS. 



For explanation of the letters and exponents designating blastomeres, see 

 explanation of the nomenclature of cleavage (pp. 74-76) . 



ast'ccel. 



app. 



at 1 . 



bl'po. 



bl'drm. 



cav.sg. 



cl.pol*. 

 d. 



Astrocoel. 

 Appendage. 

 First antenna. 

 Second antenna. 

 Blastopore. 

 Blastoderm. 

 Cleavage cavity. 

 First polar cell. 

 Second polar cell. 

 Dorsal. 



ec'bl. Ectoblast. 



en'bl. Entoblast. 



Ibr. Labrum. 



mb.vt. Vitelline membrane. 



md. Mandible. 



ms'bl. Mesoblast of double origin. 



ms'bl'. " Secondary mesoblast " (ecto- 



blastic mesoblast). 



pr'nl. $ Male pronucleus. 



pr'nl. 9 Female pronucleus. 



The Roman numerals I. II. (Figs. 28, 30) indicate the position of the first and 

 second cleavage planes, respectively ; the Arabic numerals 1-4 (Figs. 91, 93, 122- 

 126), the sequence in which the transverse furrows marking off the Nauplius 

 appendages make their appearance. 



Plate i. 



Plate 2. 



Plate 3. 



Plate 4. 



Plate 5. 



Plate 6. 



Figs. 1-16. 

 Figs. 17-22. 

 Figs. 23-30. 

 Figs. 31-38. 

 Figs. 39-46. 

 Figs. 47-55. 



Plate 7. 

 Plate 8. 

 Plate 9. 

 Plate 10. 

 Plate 11. 

 Plate 12. 



Figs. 56-65. 

 Figs. 66-73. 

 Figs. 74-86. 

 Figs. 87-94. 

 Figs. 95-110. 

 Figs. 111-126. 



