EXPLANATION OF PLATES. 



Plate 1. 



Page. 

 Fig. 1. Pyramidella ( Voluspa) cerrosana, new species, type 25.5 mm 20 



2. Pyramidella (Longchscus) bicolor Menke, type 9.8 mm 22 



3. Pyrmnidclla ( Voluspa) auricoma Dall, type 10.6 mm 20 



4. Pyramidella (Pharcidella) hastata A. Adams, type 11.5 mm 25 



The fine spiral striations have been omitted in this figure. 



5. Pyramidella {Pyramidella) hairdi, new species, type 5.1 mm 19 



The fine spiral striations have been omitted in this figure. 

 5a. Nucleus of same, lateral view much enlarged. 



6. Pyramidella (Longchscus) adarasi Carpenter, type 11.3 mm 21 



The fine spiral striations have been omitted in this figure. 



6a. Nucleus of same, lateral view much enlarged. 



7. Pyramidella (Longchseus) mazatlanica, new species, type 11 mm 24 



7a. Nucleus of same, lateral view much enlarged. 



8. Pyramidella (Pharcidella) panamensis, new species, type 8.8 mm 26 



8a. Nucleus of same, lateral view much enlarged. 



9. Pyramidella (Longchxus) conica C. B. Adams, type 13 mm 23 



10. Pyramidella (Pharcidella) achates Gould, type 9.8 mm 27 



11. Pyrainidella (Pharcidella) moffati Dall and Bartsch, type 11.5 mm. 26 



12. Pyramidella (Longchxus) mexicana, new species, type 19 mm 23 



Plate 2. 



Fig. 1. Turbonilla ( Turbonilla) ima, new species, type 9.4 mm 31 



2. Turbonilla (Chemnitzia) aculeus C. B. Adams, type 4.4 mm 38 



2a. Nucleus of same, lateral view much enlarged. 



3. Turbonilla ( Turbonilla) lucana, new species, type 6 mm 82 



4. Turbonilla (Chemnitzia) paramoea, new name, type 5.9 mm 37 



4a. Nucleus of same, lateral view much enlarged. 



5. Turbonilla (Chemnitzia) hypolispa, new species, cotype 8.1 mm 34 



5a. Nucleus of same, lateral view much enlarged. 



6. Turbonilla ( Turbonilla) centrota, new name, type 2.8 mm 30 



6a. Nucleus of same, lateral view much enlarged. 



7. Turbonilla (Chemnitzia) santarosana, new species, type 4.5 mm 36 



7a. Nucleus of same, lateral view much enlarged. 



8. Turbonilla ( Turbonilla) gilli Dall and Bartsch, type 3.3 mm 29 



9. Turbonilla ( Chemnitzia) muricata Carpenter, type 2.3 mm 36 



10. Turbonilla (Chemnitzia) xpynota, new species, type 3.2 mm 35 



10a. Nucleus of same, lateral view much enlarged. 



11. Turbonilla (Chemnitzia) muricataides Dall and Bartsch, type 3 mm 38 



11a. Nucleus of same, lateral view much enlarged. 



12. Turbonilla (Turbonilla) gilli delmontensis Dall and Bartsch, type 3.4 



mm 30 



13. Turbonilla ( Turbonilla) diegensis, new species, type 5.3 mm. 31 



13a. Nucleus of same, lateral view much enlarged. 



235 



