Plate IV. 

 Tethys cervina Dall and Simpson 



Fig. 2^. Median and first three lateral teeth of twentieth and 



twenty-first rows of radula. x 62. 

 Fig. 24. Fourth to tenth lateral teeth of same rows of radula. 



X 62. 

 Fig. 25. Eleventh to twenty-second (outermost) lateral teeth 



of same rows. The three figures of this plate represent 



the whole extent of two rows of teeth from the middle 



to the side of the radula. x 62. 



