PLATE 24 

 Teredo navalis L. 



Fig. 9. External view of the anterior end of the body from the right. Part of the 

 i ijilit valve and mantle have been dissected away. 



Figs. 10-13. Photomicrographs of cross-sections of a small male specimen, 

 anterior aspect. These four figures correspond, respectively to figures 2, 3, 4, and 5 

 on plate '22. Since the photomicrographs are of a smaller animal than that repre- 

 sented by the diagrams, the acini of the liver and the lobules of the gonad are rela- 

 tively larger in the former. Magnification ?6 diameters. 



The specimen from which these sections were made was taken from a pile at 

 Crockett, San Francisco Hay, on July 6, 1922. It was fixed in Gilson's fluid, imbedded 

 in parafin, the sections-cut 10 microns thick, and stained in Delafield's haematoxylin. 



[474] 



