524 SHODIES OK SHMIDEN DS 
By following this method on suitable material the complete 
ontogeny of any species may be worked out. In order to work 
out the phylogeny of any form it is necessary to combine this 
with comparative study of antecedent genera and species. When 
this is done for all the Ammonodea, their genealogy will be more 
perfectly known than any other family tree possibly can be. 
JIL ANAS, 413 
Fic. 1. Protoconch of Schloenbachia, showing the first six sutures of the 
attached coil. Enlarged thirty times. 
Fic. 2. Larval stage of Schloenbachia, diameter o™™.68; thirty times 
enlarged ; three-fourths of first whorl. 2a, side view; 20, front view. 
Fic. 3. Larval stage of Schloenbachia, diameter o™".64; thirty times 
enlarged. Showing sutures from the third to the tenth. From above. 
Fic. 4. Larval stage of Schloenbachia, diameter 1™™.20; fifteen times 
enlarged. One anda half whorls. 4a, front view; 44, side view. 
Fig. 5. End of larval stage of Schloenbachia, diameter 2™™.25 ; fifteen 
times enlarged. Paralegoceras stage. 5a, side view; 50, front view. 
Fic. 6. Cross section of Schloenbachia, diameter 6™™.25; fifteen times 
enlarged; four whorls. Adolescent stage. The protoconch is seen in the 
center P. 
Fig. 7. Cross section of Schloenbachia, 22™™.25; three and a half times 
enlarged; six whorls. Adult stage. 
JAMES PERRIN SMITH. 
STANFORD UNIVERSITY, 
California. 
