158 CALIFORNIA ACADEMY OF SCIENCES. [Proc. ^n Ser. 



EXPLANATION OF THE FIGURES. 

 Plate XIX. 



Phylloceras onoense Stanton. 



Fig. I. Protoconch and three chambers, diam. 0.45 mm., front view, forty 



times enlarged. 

 Figs. 2, 3. Larva, one and one-sixth coils, diam. 0.87 mm., forty times 



enlarged. 

 Figs. 4, 5. Larva, one and three-fourths coils, diam. 1.42 mm., twenty 



times enlarged. 

 Figs. 6, 7. Transition from larval to adolescent stage, two and one-sixth 



coils, diam. 1.90 mm., twenty times enlarged. 

 Fig. 8. Outline at diam. 2.46 mm., twenty times enlarged, adolescent 



stage. 

 Fig. 9. Outline at diam. 4.50 mm., thirteen times enlarged. 

 Fig. JO. Outline at diam. 7.00 mm., seven times enlarged. 

 Fig. II. Outline at diam. 10.00 mm., four times enlarged. 



