382 EDWARD S. MOUSE ON 



Fig. 3. Longitudinal section. 



Fig. 4. Bend of into.stiiic and iifduuciilar fanal. 



Fig. 5. Peduncular canal. 



Fig. 0. Stomacli with gastro- and illn-panetal liands. 



Fig. 7. 1). Stella, .showing head and lirachia. 



TLATE .'■)0. 



Details of alimentary tract of various forni.s. 

 Fig. 1 to 10. dlottidia pyramidata. 



Figs. 1 and 2 Longitudinal sections of mouth parts. 



Figs. 3 and 4. Moutli and bracliia from ventral .side showing mobility of tlie lips. 



Fig. 5. Dorsal view of pharyngeal region. 



Fig. G. Roof of pharynx from inside, showing triturating ridges. 



Figs. 7 and 8. Ventral and doreal views respectively of .stomacli and portion of intestine. 



Fig. 9. Transverse section of intestine showing attachment of ilio-]iarielal band. 



Fig. 10. Anus. 



Figs. 11 and 12. Rectum and aiuis of L. Ipjyldula. 



Fig. 13. Portion of right coelomic wall of D. lamellosa showing anus. 



Figs. 14 and 1.5. Gut of 1). lamellosa from an early stage. 



Fig. 16. Section of gut of T. xeptentrinnaUa. 



Fig. 17. Digestive tract of H. pslttacea, with stomachal glands removed. 



Fig. 18. Anterior ]iortion of digestive tract of TI. pnMarea showing stomachal glands. 



PLATE .51. 



Stomachal glands, sense organs and nerves of various forms. 

 The following figures represent a single coecum, or a cluster of coeca of the stomachal glands, unless otherwise mentioned . 

 Fig. 1. 0. pyramidata. 

 Fig. 2. L. anaiina. 



Figs. 3, 4, an<l H. Showing the entire cluster on one or both sides of the stomach of young J), lamellosa. 

 Fig. 0. n. Stella. 



Figs. 7 and 8. T. septentrional is. 

 Fig. 9. T. coreanica. 

 Figs. 10 and 11. H. psittaeea, young. 

 Fig. 12. H. psittaeea, adult. 

 Fig. 13. Dallina (jrayii. 



Fig. 14. Longitudinal section of mouth parts of (I. pyramidata, showing infr.i-oesophageal ganglion and nerve. 

 Fig. 15. Pallial folds with pigmentation, supposed to be sensitive to light, idem. 

 Fig. 16. Greatly enlarged view of pigmentation of one fold. 

 Figs. 17 and 18. Nerve and otocyst of L. lepidula. 



Fig. 19. Nerve with nerve twigs and section of nerve of G. yi/raiiiidata. 

 Fig. 20. Otocyst of L. anatina. 



PLATE .52. 

 Nerves and other details of various forms. 

 Figs. 1 and 2. Otocyst and surrounding parts of L. lepidula. 



Fig. 3. Infra-oesophageal ganglia of D. Stella. 



