Trans. Wis. Acad., Vol. XI. 
Plate XXXIII. 
0- 3 m Mch. Ape. Mat. June. July. Aug. Sept. Oct. Nov. Dec. 
Fig. 23. —Population of the 3 m. levels, 1896. Scale, 1 vertical space 
= 100,000 Crustacea per sq. meter. See p. 387. 
