NO. 1569. WEST AMERICAN MOLLVSKS—BARTSCH. 255 



TRIPHORIS PENINSULARIS, new species. 

 Plate XVI, fig. 2. 



Shell sinistral, small, broadly elongate, conic, dark brown. Nuclear 

 whorls four, light brown, increasing regularly in size, provided with 

 spiral and axial sculpture (but this is too badly worn to l)e properly 

 diagnosed in all our specimens). Post-nuclear whorls eight, sepa- 

 rated by channelled sutures. The first four post-nuclear whorls 

 have a double spiral row of tubercles, the posterior row being a little 

 more strongly developed than the anterior. These rows are sepa- 

 rated by a channel about as wide as the tubercular ridges. Begin- 

 ning with the fifth whorl, a slender tuberculate cord appears in the 

 middle of the channel which separates the two spiral ridges; this 

 grows steadily in size with each turn, until on the last volution it is 

 quite as strong as the suprasutural cord. On the later turns the 

 middle and suprasutural spiral cords and their tubercles fall off quite 

 abruptly at their posterior border and slope roundly toward their 

 anterior limit. The tubercles on all the turns are joined b}^ rather 

 w^ide spiral bars and axial ribs, which inclose deep squarish pits 

 between them. Periphery and base of the last turn well rounded, the 

 former marked by a low somewhat flattened keel, which is separated 

 from the supraperipheral cord by a channel as wide as the one which 

 separates the supraperipheral J^eel from the middle one. The channel 

 is crossed by the extension of the axial riblets. The base is marked 

 by two spiral cords about as broad and of the same character as the 

 peripheral one. These cords are separated by channels as broad as 

 that which separate the peripheral cord from the supraperipheral 

 one and are crossed by feeble extensions of the axial riblets. The 

 anterior basal cord is situated upon the base of columella and its 

 anterior border fuses almost imperceptibly with it. The entire sur- 

 face is crossed by many exceedingly fine spiral striations and lines of 

 growth. Aperture subquadrate, posterior angle obtuse, anteriorly 

 strongly channelled; outer lip subpatulous anteriorly, not sinuous; 

 columella short, thick, twisted. Columella and the parietal wall are 

 covered with a strongly developed callus. 



There are three specimens of this species in the collection of the 

 U. S. National Museum, Cat. No. 106424, collected by ^Ir. Henry 

 Hemphill, at Point Abreojos, Lower Califorina. The type, which is 

 one of these tliree, has lost three of its nuclear whorls; the remaining 

 nine turns measure: Length, 4.0 mm.; diameter, L5 mm. 



TRIPHORIS EXCOLPUS, new species. 



Plate XVI, fig. 8. 



Shell sinistral, with alternating brown and white zones. (Nuclear 

 whorls decollated.) The first three of the succeeding turns are 

 marked by a double spiral row of tubercles. On the first two turns 



