No. 2.] THE ECHINODERM SPERMATOZOON. 



265 



DESCRIPTION OF PLATES. 



All figures except 6, 7, 8, 9, 10, ii, 12, and 13 are magnified 1500 diameters. 

 Camera drawings, with Zeiss 3 mm., 1.30 apert. apochrom. hom. immers. objective, 

 and compensating ocular 18. All the details so far as possible are drawn to scale. 

 The coloring was done directly from the preparations. 



Only in Figs, i, 2, 3 A, 4 A, 5 C and D, 35, 36, 40, 42, 43, 44, 45, 48, 50, and 55 

 is the length of the tail represented. 



