Fic. 
9) 
EXPLANATION OF PLATE XVII. 
Atopos (Parapodangia) gravelyi, n. sp. | 
8.—Longitudinal section of the radular portion of the pro- 
boscis (diagrammatic) in the middle line. 
g.—Transverse section of the same, a-b. 
10.-— Dorsal view of the aperture of the radula sac. 
11.—A tooth of radula [Zeiss ocular vi, Leitz obj. 6]. 
12.—Longitudinal section of radula sac. [Zeiss ocular vi, 
Leitz obj. 3]- 
13.—A portion of the same, marked B roughly in fig. 12. 
I4.—A portion of the same as in fig. 12, marked A. 
15.—Digestive gland, X I. I, oesophagus; 2, rectum. 
16.—Anterior portion of digestive gland, ventral view, X I. 
17.—'Transverse sections of the digestive gland at various 
levels shown in fig 15. 
