182 BULLETIN 37, UNITED STATES NATIONAL MUSEUM. 



PLATE XVIII. 



FIG. 1. Scala hellenica var. Morchiana Dall ; 6.87. 



2. Scala discobolaria Dall ; 6.5. 



3. ActcKon pcrforatus Dali ; 7.75. 



4. Scala aurifila Dall ; 11.0. 



5. Niso inlemt-pta Sowerby var. albida Dall ; 8.1. 



6. Niso interrupta var. albida Dall, base ; 3.5. 



7. Aclis nucleala Dall; 9.3. 



8. Aclis lata Dall ; 5.5. 



9. Scala contorquata Dall ; 4.7. 



10. Scala polacia Dall, aperture imperfect ; 7.25. 



11. Scala formosissima Jeffreys ; 8.5. The aperture is a little distorted where 



it joins the body whorl. 



11 b. Scala belanrita Dall ; 8.3. 



12. Aclis egrefjia Dall; 13.0. 



PLATE XIX. 



FlG. 1. Rissoa precipitata Dall ; 4.0. 



2. Marginella seminula Dall ; 7.0. 



3. Marginalia Watsoni Dall ; 9.5. 



4. Marginella fusina Dall ; 8.0. 



5. Marginella yucatecana Dall ; 5.62. 



6. Marginella succinea Courad ; 12.0. 



7. Marginella torticula Dall; 11.5. 



8. Columbella (Anachis ?) Verrillii Dall ; 9.0. 



9. Pedicularia decussata Gould, profile ; 6.0. 



9 b. Pedicularia decussata, young, showing spiral apex; 2.5. 



10. Eissoa xantlnas Watson, var. acuticostata Dall ; 3.7. 

 10 b. Eucosmia brei'is Orbigny ; 2.0. 



10 c. Columbella ( Anachis) amphissella Dall ; 4.0. 



10 d. Dalium solidiim Dall ; 41.0. 



11. Eulima (Melanella) arcuata C. B. Adams ; 4.0. 

 lib. Leiostraca fusus Dall ; 13.5. 



lie. Eulimella unifasciata Forbes ; 6.0. 



PLATE XX. 



FIG. 1. Cerithiopsis Sigsbeeatia Dall ; 10.5. 



2. Cerithiopsis Martensii Dall ; 11.25. 



3. Cerithiopsis crystallina Dall ; 16.0. Poor figure. 



4. Eumeta subnJata Montagu ; 14.25. 



5. Cerithiopsis abrupta Watson ; 4.3 



5 a. Triforis triserialia Dall ; 8.25. 



6. Ti iforis ci/lindrella Dall ; 6.5. 



6 a. Triforis triserialis Dall ; 15.5. 



7. Mathilda yuc,atecatia Dall ; 8.0. 



8. Triforis triserialis var. intermedia Dall ; 11.0. 



9. Triforis abrupta Dall ; 7.5. 



10. Triforis longissima Dall ; 26.0. 



11. Triforis bigemma var. hircus Dall; 12.5. 



11 b. Triforis torticula Dall ; 10.5. 



12. Triforis colon Dall ; 12.0. 



12 b. Triforis infiata Watson var. ibex Dall ; 11.0. 



