PLATE IV. 



ANATOMY OP THE DORCASIINAE. 



Figs. 1-6. Pallial organ* seen from below, showing the arrangement of the 

 pulmonary veins, with the mantle-edge and left body-lobes above, the pericardium 

 and kidney below, and the rectum on the left side. (Somewhat diagrammatic.) 

 Fig. 1. Trigonephrus globulus (Mull.). 

 ,, 2. T. porphyrostoma (M. & P.). 

 ,, 3. T. namaquensis (M. <t P.). 

 ,, 4. T. lucanus (Miill.). 

 ,, 5. Dorcasia coagulitm (v. Mts.). 

 ,, 6. D. ale.ramiri, var. rotnndata, Mouss. 



Figs. 7 & 8. Dorsal views of buccal mass, showing the end of the radula-sac 

 and the opening of the oesophagus. (Natural size.) 



Fig. 7. TrigonepJuiis globulus (Miill.). 



,, 8. T. namaquensis (M. & P.). 



Figs. 9-16. Representative teeth from the radula (seen from above). 

 Fig. 9.Trigonephru8 globulus (Miill.) x 150. 

 ,, 10. T. rosaceus (Miill.) x 150. 

 ,, 11. T. porphyrostoma (M. & P.) X 150. 

 ,, 12. T. namaquensis (M. & P.) x 150. 

 13. T. litcanus (Miill.) x 175. 

 ,, 14. Dorcasia coagulum (v. Mts.) x 250. 

 ,, 15. D. rogersi, nov. x 250. 

 ,, 16. D. alexandri, var. rotnndata, Mouss. x 250. 

 Figs. 17-24. Anterior views otjaw. 



Fig. 17. Trigonephrus globulus (Miill.) x 7'5. 

 ,, 18. T. rosaceus (Miill.) x 7 - 5. 

 ., 19. 2'. porphyrostoma. (M. & P.) x 7-5. 

 ,, 20. T. namaquensis (M. & P.) x 7-5. 

 ,, 21. T. lucanus (Miill.) white var. x 7'5. 

 ,, 22. Dorcasia coagulum (v. Mts.) x 10. 

 ,, 23. D. rogersi, nov. x 10. 

 ,, 24. D. alexandri, var. rotnndata, Mouss. x 10. 



Figs. 25 & 26. Digestive system, seen from above, after the intestine and 

 rectum, with the anterior division of the liver, have been turned over to the left. 

 Fig. 25. Trigonephrus porphyrostoma (M. & P.) x 1. 



26. Dorcasia coagulum (v. Mts.) x 2. 

 Figs. 27-30. Part of the wall of the penis, seen from within. 

 Fig. 27. Trigonephras globulus (Miill.) x 6. 

 ,, 28. T. porphyrostoma (M. & P.) x 5. 

 ,, 29. T. lucanus (Miill.) x 6. 

 ,, 30. Dorcasia coagulum (v. Mts.) x 6. 



