TRIFORIS. 187 



T. TRISTOMA, Blainv. PI. 39, fig. 42. 



Whorls 15, triseriately tuberculated, the upper row strongest, 

 suture whitish, channeled, with a minute row of granules ; yellow- 

 ish-chestnut, with a row of darker spots between the granules of 

 the lower series. Length, 12 mill. 



Australia. 



The species was based upon its " three-mouths," and can no longer 

 be identified with certainty. 



T. EXILIS, Dunker. PL 39, fig. 45. 



Whorls 10-11, triseriately granose, suture narrow, not deep, 

 brownish, with a lighter line. Length, 5 mill. 



Japan. 



T. PERVERSUS, Linn. PI. 39, figs. 44, 51. 



Whorls about 16-18, flat, clathrate, with three series of revolving 

 and numerous longitudinal riblets, the intersections nodulose, body 

 whorl with four spiral series, below which are two spiral ribs ; yel- 

 lowish brown, or chestnut color. Length, 15-30 mill. 



Europe, Canary Is. 



Thje synonyms are T. Maroccamis, Brug., T. radula, Olivi, T. 

 retieulatus, Donov., T. gramdosus, Scacchi, T. tuber cularis, Blainv., 

 T. seriatus, Muhlf., T. inversus, Costa, T. Savignyanus, Chiaje, to 

 which European authors often add Cerithium pusillum, Pfr. 



Var. BENOITIANUM, Aradas. 



Established on a single individual 34*5 mill, long, with four series 

 of granules on the spire and five on the body whorl, lip much 

 dilated. 



Ognina. 

 Var. ADVERSA, Montg. Fig. 51. 



Shell smaller, 15 mill. long. This == var. minor, Monts., and T. 

 Belli. Wood. It is found also on the California coast at least no 

 differences have been detected between these and European 

 examples. 



There are also vars. cylindrata, obesula and atteiiuata, Monts., 

 founded upon the form of the shell, and the following color-varieties. 



Yar. BICOLOR, Mts. Brown, with white tubercles. 

 Var. CINCTA, Mts. Brown, with a white median zone. 

 Var. PALLESCENS, Jeffreys. Light fawn color. 

 Var. LACTEA, Mts. White. 



