266 TORN ATELL ARIA. 



Columella nearly straight, expanded above the umbilicus, with 

 two well developed lamellae extending to the outer margin of 

 the columella. Peristome thin, erect, slightly arcuate. Length 



4.5, diam. 2.5, axis of apert. 1.8 mm. Height of parietal la- 

 mella 0.35 mm. 



Hawaii: Hilo (Thaanum), Olaa (Thaanum, Cooke). Type 

 no. 14194 Bishop Mus. Cotypes 33959 and 14018 Bishop 

 museum; 111858 A. N. S. P. and in Mr. Thaanum 's collection. 



T. sykesii is closely related to T. henshawi. In the former 

 the shell is shorter, stouter and the spire has slightly more 

 convex outlines. The parietal lamella is stronger, with min- 

 ute serrations along its inner margin and the front end is 

 usually eroded. In T. syUesn the columellar folds are more 

 strongly developed. A pale peripheral band is never present 

 in T. henshawi. 



The shell differs from T. a. hawaiiensis by having two 

 strongly developed and subequal columellar lamellae, and the 

 broad, outwardly flaring parietal lamella is eroded and irre- 

 gular in front. It is three-fourths of a whorl long. Color 

 cinnamon-buff. An Olaa specimen measures, length 4.4 ; diam. 



2.6, length of aperture 1.75 mm. ; 7^4 whorls. 



It is less glossy and darker colored than T. smithi, and 

 it has a much more prominent parietal lamella. The umbili- 

 cus is about one-eleventh of the total diameter. 



In immature specimens the lower columellar fold is slightly 

 stronger than the upper. There are about 12 fine low spiral 

 striae on the embryonic whorls. 



lla. T. SYKESI ILLIBATA C. & P., n. var. PL 55, fig. 7. 



In size, form and color-pattern this variety agrees closely 

 with the typical form from Hawaii. The parietal lamella of 

 illibata is lower, without the minute serrations on its inner 

 margin and its front margin is never eroded. The columellar 

 folds are much weaker. In young specimens the lower colu- 

 mellar fold is much stronger than the upper. There are about 

 12 distinct spiral striae on the embryonic whorls. 



Length 4.5, diam. 2.5, axis of apert. 1.8 mm. Height of 

 parietal lamella 0.27 mm. 



