60 BULLETIN 90, UNITED STATES NATIONAL MUSEUM. 



OLIVELLA EUTORTA, new species. 

 Plate 10, fig. 10. 



Shell small, stout, solid, with 5^ whorls separated by a deeply- 

 channeled sutnre; first whorl rounded and siibglobular ; subsequent 

 whorls smooth, moderately convex; aperture wide in front, behind 

 ending in a deep narrow sinus at the end of the suture, between the 

 body and the outer lip; anterior third of the body covered by a 

 revolving band of enamel with a groove at the posterior edge, other- 

 wise smooth; the outer lip sharp, smooth within; body with a thin 

 wash of callus, pillar thick, callous, twisted, with its anterior edge 

 forming a strong rounded fold with a depression behind it, the inner 

 surface of the pillar finely spirally Urate; canal wide, shallow. 

 Length, 12; length of aperture, 8.5; maximum diameter of shell, 

 6 mm. 



Tampa silex beds at Ballast Point, Tampa Bay, Florida. 



Type-specimen from the Post collection, U. S. Nat. Mus. No. 

 165047. 



OLIVELLA COLLETA, new species. 

 Plate 12, fig. 9. 



Shell very small, smooth, slender, with about 5^ whorls, separated 

 by a deeply channeled suture; nucleus minute subglobular, of about 

 one whorl; subsequent whorls subcylindrical, smooth; last whorl 

 attenuated in front, with a faint fasciolar band of enamel close to 

 the anterior edge; aperture narrow behind, wide in front; outer lip 

 thin, sharp, simple; inner lip not callous; pillar with one or two 

 faint very anterior folds ; canal wide and deep. Length of shell 4.5, 

 of aperture 2.5, maximum diameter 1.8 mm. 



Tampa silex beds at Ballast Point, Tampa Bay, Florida. 



One specimen from the Post collection, U. S. Nat. Mus. No. 165048. 



Genus ANCILLA Lamarck. 



Ancilla Lamarck, Prodrome, p. 90, No. 6, 1799. Type, Voluta ampla 

 Gmelin ; Syst. an. s. Vert. 1801, p. 73 ; sole example cited, A. cinnamomea 

 Lamarck ; Dall, Trans. Wagner Inst., vol. 3, pt. 2, p. 225, 1892. 



Ancillaria Lamarck, Ann. du Mus., Paris, vol. 16, p. 305, 1811. Not An- 

 cilia Meuscheu, 1787. 



The name of this genus was changed by Lamarck because it was 

 thought too close to Ancylus (Geoffroy) Miiller, 1774. Meuschen's 

 name is misspelled Ancilla in the Index Animalium, but in any case, 

 as his system was frankly not Linnean, we are fortunately not 

 obliged to consider his names, which are all in the plural number 

 and not systematically binomial. 



