, PLATE XIX. 



Figs. 1-6. riiilomedes lomae, male. 



1. Shell of adult. X 52. 



2. Frontal organ. X 190. 



3. Shell of young. X 52. 



4. Mandible. X 105. 



5. Portion of mandibular palp, showing sensory appendage. X 



6. Furea. X 105. 



Figs. 7-11. Cylindroleheris mariae. 



7. Shell of female. X 52. 



8. Shell of male. X 52. 



9. Frontal organ of male. X 275. 



10. Secondary branch of female antenna. X 275. 



11. Secondary branch of male antenna. X 193. 



Fig. 12. Pleoschisma ohlonga, shell of male. X 57. 



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