XXVI 



INTEOBUCTION. 



Fig. ii. 



A. Sakiella honeda, enlarged. Dorsal side, viewed from above, to show 

 . position of the pericardium (^j), heart with auricle {ah) and veutricle {vh), 



kidney {Jc), pulmonary cavity [pc), liver (I), anu* («), mantle-edge {m). 

 A'. Dorsal side, seen from below. Eectum {rev), kidney-opening iko), 

 pulmonary vein {l^v), right shell-lobe {rsl), left shell-lobe {hi). 



B. Microcystis amhce, showing embryonic shells within the oviduct, x 9. 



B'. An embryonic shell, showing development of the foot, with eye and 

 anal and respiratory orifices. X 44. 



C. Shell of Sitala attegia. Diagram to illustrate the different parts and 



usual measurements. 



D. A spermatophore of Sesara infrendens, much enlarged. After Stoliczka. 



Parts of the shell and ustcal measurements. 



1-7. The a])ical whorl to the 7th 

 (the last or body-whorl). 

 .5. The antepenultimate whorl. 

 6. The penultimate whorl. 



8. The apex. 



9. The umbilical region. 

 8-9. The axis. 8-14. Spire. 



10. The aperture : the upper, 

 outer, and inner angles of, 

 the interval between being 

 the wall 01 the aperture. 



11. The peristome and outer 



lip. 



12. The columellar margin. 



13. The suture. 



14. The periphery or keel. 

 A-B. Major diameter. 

 A-C. Height of shell. 

 A-D. Do. of axis. 



E-F. Do. of aperture. 

 G-II. Breadth of aperture. 



