110 BULLETIN 90, UNITED STATES NATIONAL MUSEUM. 



Section SENECTUS Swainson. 



Henectus Swainson, Mai., pp. 214, 348, 1840. Type, Turho clirysostomus 

 Linnaeus. 



This group was indicated by Da Costa in the anonymous Museum 

 Calonnianum, which has been excluded from nomenclature by the 

 International Committee's decision. 



TURBO (SENECTUS) CRENORUGATUS Heilprin. 



Turho crcnorngatus Heilprin, Trans. Wagner Inst., vol. 1, p. 113, pi. 16, 

 fig. 54, 1887.— Dall, Trans. Wagner Inst., vol. 3, pt. 2, p. 382, 1892. 



Tampa silex beds at Ballast Point, Tampa bay, Florida ; Heilprin, 

 Willcox, Burns, and Dall. U. S. Nat. Mus. No. 112984. 



This species is not uncommon among the silicified fossils at 

 Ballast Point, but rarely found in good condition, and, so far, always 

 immature. That it must grow to a much larger size than any yet 

 reported is certain, since Mr. Willcox found an operculum which 

 measured in greatest diameter 31 mm., more than twice the size of 

 any which fit the aperture of the largest shell yet found at the same 

 locality. 



Genus ASTRAEA Bolten. 



Astraea Bolten, Mus. Boltenianuni. 1798, p. 79. Type, Trochus itnperialis 



Gmelln. Not Astraea Lamarck, 1801. 

 Astraea Dall, U. S. Geol. Surv,, Prof, ijaper No. 59, p. 92, 1909. 

 Astralium Link, 1807. 

 Imperator Montfort, 1810. 



Subgenus LITHOPOMA Gray. 



Lithoponia Gray, Fig. Moll. An., vol. 4, p. 88, 1850. Type, Trochus tuber 

 Linnaeus. 



ASTRAEA (LITHOPOMA), sp. indet. 



Astraliumi sp. indet. Dall, Trans. Wagner Inst., vol. 3, pt. 2, p. 385, 1892. 



An indeterminate species of Astraea is represented by fragments 



and imperfect casts from the Tampa silex beds and the limestone of 



Walmlla County, near Wakulla, Florida; Dall and Vaughan. Also 



in the Chipola marl of Calhoun County, Florida ; Burns. 



Family TROCHIDAE. 



Genus TEGULA Lesson. 



Tegula Lesson, 111. de Zool., livr., 17, 1834, pi. 51 (no pagination on the 

 text). Type T. elegans Lesson,=!r. pellis-serpentis Mawe. 



Tegula, being the older name, takes precedence over Chlorostoma 

 and Omphalius as subgenera, if the latter be accepted as valid groups. 



