Pomona College, Claremont, California 149 



EXPLANATION OF FIGURES 



Figure I. Longitudinal section through a radial nerve of Lyieih'tnus anamesus H. L. 



C. The aboral end is toward the top of the page. X75. 

 Figure 2. Cross section through a large part of a radial nerve of Lytechhius. A 



branch to a tube foot is shown at the right. X160. 

 Figure 3. Cross section of a radial nerve of Lytechhius nearer one end than Fig. 2. 



X160. 

 Figure 4. Cross section through the band of nervous tissue found at the base of one 



of the larger spines of Lylechintis. X160. 

 Figure 5. Section through a radial nerve of Lytechinus, drawn with best oil objective 



obtainable. X750. 

 Figure 6. Section through a radial nerve of Stronyylocenlrotus franclsconus A. Ag. 



Drawn the same as Figure 5. X750. 



