MORPHOLOGY OF OTOCYSTS OF GONIONEMUS. 



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vesicle (sv) completely envelope the secondary pedicel (sp). 

 The true otolith (o) is shown within the secondary vesicle. In 

 the section from which this drawing was made a small tangential 

 slice such as is shown in Fig. 3, Plate I., had been cut from the 

 surface of the spheriod thus disclosing the cavity of the sec- 

 ondary vesicle. No sensory hairs or ridges were demonstrated. 

 Perkins ( 1902 : 786) also calls attention to the absence of such 

 structures, though his observations were probably confined 1 to 

 the walls of the primary vesicle. In sections a thin tangential 

 slice from the surface of the spheroid. Text Figure 2, may at 



TEXT FIGURE 2. Tangential slice only partly removed from wall of 

 spheroid. 



first glance remind one of the projections figured by Hertwig 

 (1879: 183, Figs, i and 2) for Cannarina. 



The primary pedicel measures 0.043 nim - m diameter and 0.069 

 mm. in length. At its proximal end a single large nucleus is 

 found. This pedicel is very delicate for in sectioning, it, together 

 with the spheroid, is often torn loose from the cyst wall. In 

 other cases only the spheroid is torn away from the distal end of 

 the pedicel and may be found elsewhere on the slide. Goto 

 (1903: 8) records encountering the same difficulty in the prepara- 

 tion of sections. 



The secondary pedicel measures 0.115 mm. in length. Its 

 diameter near the middle is about 0.023 min. but the distal end is 



