NO. 1569. WEST AMERICAN MOLLUSKS—BARTSCH. 257 



are about fourteen tubercles on the fourth (the first sculptured) 

 whorl and twenty-four on the tenth and the penultimate turn. On 

 the last ten whorls the tubercles at the summit of the whorls are 

 considerably stronger than the other two and darker colored. The 

 sutures on the later whorls are deeply channeled; the channels are 

 crossed by a slender riblet at each tubercle. Periphery of the last 

 whorl marked by a strong keel which is weakly tuberculate. Base 

 marked by two spiral keels a little weaker than the peripheral one. 

 These two are ornamented by feebly developed tubercles, the deep 

 channels between them being crossed by the continuations of the 

 slender axial riblets. Aperture of irregular outline; posterior angle 

 well rounded, strongly channeled anteriorly; outer lip sinuous to 

 correspond with the external sculpture; columella very strong, 

 twisted. 



The type, Cat. No. 56014, U.S.N.M., is from Panama. It has 

 seventeen whorls, and measures: Length, 8.7 mm.; diameter, 2.2 nun. 



TRIPHORIS DALLI, new species. 



Plate XVI, fig. 14. 



Shell acicular, increasing regularly in size, irregularly variegated 

 with varying shades of brown, yellow, and white. Nuclear wdiorls 

 four, browm, marked by two strong, narrow spiral tlii-eads wliich divide 

 the space between the sutures into tlu'ee parts, of whicli the anterior 

 two are about equal, while the posterior one is a little wider than the 

 rest. In addition to the spiral tlu'eads, the surface is marked by 

 many regular, slender, axial riblets, almost as strong as the spiral 

 keels; of these there are about tliirty upon the second and twenty- 

 eight upon the fourth turn. The fu-st tlu-ee postnuclear turns are 

 white, the remaining variegated. The early ones are marked by a 

 double row of tubercles, one at the summit, the other at the periphery, 

 separated by a broad channel. The anterior one is the stronger. 

 Beginning with the fourth turn, a slender thread makes its appearance 

 in the intermediate channel, a little posterior to the middle. This 

 remains slender and on none of the turns, not even the last, becomes 

 as strongly developed as the other two. The postnuclear whorls 

 are also marked by poorly developed, rather broad, axial riblets, the 

 intersection of which with the spiral keels marks the tubercles. The 

 tubercles slope more abruptly posteriorly than anteriorly. The 

 entire surface is crossed, in addition to the above-described sculpture, 

 by microscopic spiral and axial lines. Sutures strongly impressed. 

 Periphery of the last whorl marked by a well-impressed channel. 

 Base rather short, evenly rounded, marked by tlii-ee keels, of which 

 the fu'st adjoins the peripheral sulcus and is beaded and colored like 

 its posterior neighbor. The other two keels are not tuberculate and 



Proc. N. M. vol. xxxiii— 07 17 



