304 UMBILICUS. 



TUEEIS. Montf. 1810. A genus composed of those species of 

 MiTEA, Auct. wHch have the whorls angulated, with the aperture 

 lengthened and undulated. 



TUEEITED. The spire of an univalve shell is said to be turrited 

 when the whorls of which it is composed are regulated so as to 

 have the appearance of little turrets rising above each other, as 

 in Mitra, fig. 431. Vulpccula, Gray. 



TTJEEITELLA. Lam. Terebellum, Erowne. {A little tower.) 

 Fam. Turbinacea, Lam. Cricostomata, 'Bl.—Descr. Turrited, 

 elongated, generally grooved spirally ; spire pointed, consisting 

 of numerous whorls ; aperture rounded or angulated ; inner and 

 outer lips thin, confluent anteriorly ; operculum horny. — Obs. 

 The shells composing this well-defined genus, are commonly 

 called screws, a name to which the spiral grooves of most of the 

 species seems to entitle them. Mr. Eeeve's Monograph contains 

 sixty-five species. T. imbricata. PI. xvi. fig. 370. 



TUETONIA. Hanley. See "Kelliad^," T. minuta, PI. xxvii. 

 fig. 567. 



TYMPANOSTOMA. Schum. (^Timbrel mouth.) Potamis, Brongn. 

 Potamus muricata, fig. 377. 



TYPHIS. Montf. A genus composed of Mueex tubifer, Auct. 

 and other similar species, which have the canal closed and a 

 perforated tube between each varix on the angulated part of the 

 whorls. Besides the fossil species originally described, there are 

 now five species known, which are figured in part 200, of the 

 Conchological Illustrations by the Author. Typhis tubifer, 

 PI. xvii. fig. 397. PI. xxvi. fig. 554, 555, 556. 



ULTIMIIS. Montf. (The last.) A genus composed of Ovulum 

 gibbosum, Auct. and other species in which the canals are not 

 distinctly defined, nor elongated. This fanciful name is given 

 to the genus on account of its being described in the last page 

 of the book. PL xx. fig. 443. 



UMBILICATED. (Umbilicatus.) Having an umbilicus, as Kau- 

 tilus umbilicatus. 



UMBILICUS. (A navel.) The hollow formed in spiral shells 

 when the inner side of the volutions do not join each other, so 



