258 TECTARIUS. 



T. TECTIFORMIS, Watson. PJ. 47, fig. 55. 



Umbilicated, with longitudinal plications, small at the suture, 

 then becoming evanescent, but reappearing more prominently at 

 the periphery, where they become tubercles on the carina, vanishing 

 on the flattened base, peripheral carina visible on the spire-whorls, 

 whole surface covered by fine, unequal spiral threads; yellowish 

 white. Length,? 22'5 mill. 



Japan; 565 fins. 



The apex and base of the single specimen obtained were broken. 

 Watson is not certain of the generic position of this shell, which 

 was obtained by the Challenger Expedition. 



T. MURICATUS, Linn. PL 48, fig. 68. 



Imperforate or rimate, solid, yellowish or greyish white ; whorls 

 rounded, a little flattened below the suture, encircled by close series 

 of granules, the series either in juxtaposition or with intermediate 

 spiral striae; aperture light chestnut color, usually smooth within, 

 or very faintly ridged. Length, 1 in. 



West Indies, Bahamas, Florida. 



This species has been known to live about a year in a cabinet. 

 deprived of its native element. 



T.NODULosrs, Gmel. PL 47, %s. f>!M>4; PL 48, figs. 72. 74, 75. 



Bluish grey, spirally striate, whorls biangulate in the middle, the 

 angles tuberculated, usually yellowish white, aperture and columella 

 chestnut or chocolate color, the former often obsoletely banded, 

 base of aperture a little produced. Length, 18 mill. 



North Carolina, Balunnn*, \\'e*t /y/<//Vx, Ccyton, Philippines, 

 Australia, Neiv Zealand, Marquesas. 



T. dilatatus Orb. (fig. 60), T. tuberculatus, Menke, T. thiarella, 

 Anton, (fig. 59), T. trocliiformis, Phil., T. nodu/osu*, d'Orb., not 

 GmeL, T. tuberculatus, Gray (fig. 74), T. Antoni, Phil., T. *c<iln-n, 

 Anton., are all synonyms referring to the American form, generally 

 known as T. dilatatus; whilst the oriental examples have been 

 heretofore known as T. nodulo&us (fig. 75), with T. trochoides, Gray 

 (fig. 61), T. vilis, Menke (fig. 64), T. Malaccana, Phil. (fig. (J3), T. 

 monilifera, Soul. (fig. 62), T. pyramidalis, Quoy. (fig. 72), and T. 

 trochiformis, Dillw., as synonyms. My sufficient justification in 

 uniting species with such distant habitats, and no intermediate lo- 

 calities, is that it is impossible to distinguish them by any character. 



