q8 E. L. SHAFFER. 



EXPLANATION OF PLATES. 



All drawings (except Figs. 28, 29, 30) were made with camera lucida using Nc. 

 12 ocular and 1/16 mm. oil immersion objective. Figs. 28, 29, 30 were made 

 using No. 18 ocular and 1/16 mm. oil objective. 



PLATE I. 

 (Figs, i to 12.) 



FIGS, i to 6. Metaphase plates of spermatogonia in the six beetles studied all 

 showing 20 chromosomes including an unequal pair (XY). 



FIG. i. L. delata. 



FIG. 2. L. fusca. 



FIG. 3. L. tristis. 



FIG. 4. L. gracilis. 



FIG. 5. Pelidonota. 



FIG. 6. Cotalpa. 



FIG. 7. Metaphase plate of follicle cell from ovary of L. delata showing ten 

 equal pairs. 



FIGS. 8 to 12. Metaphase plates of ist spermatocytes showing ten bivalent 

 chromosomes. 



FIG. 8. L. delata. 



FIG. 9. L. fusca. 



FIG. 10. L. gracilis. 



FIG. ii. Pelidonota. 



FIG. 12. Cotalpa. 



