Plate 1. 



Page. 



Fig. 1. Dentalium laquentumYerriW. Greatly enlarged sculptural detail 23 



2. Dentalium texasianum Philippi. Posterior section 27 



3. Dentalium laqueatum Verrill. Tip greatly enlarged 24 



4. Dentalium, texasianum, texasianum Philippi, 24 mm 28 



5. Dentalium texasianum texasianum Philippi, 21 mm 28 



6. Dentalium laqueatum laqueatum. Verrill, 2() mm 24 



7. Dentalium laqueatum laqueatum Verrill, 54 mm 24 



8. Dentalium laqueatum, regulare, new subspecies. Type. 40.5 mm 26 



9. Dentalium texasianum Philippi. Anterior section 27 



152 



