LYROPUPA. 271 



at the inner end, its free edge being reflected towards the 

 suture. The very deeply placed columellar lamella is not 

 visible in a frontal view; it is stout and semicircular. The 

 upper palatal fold is long, its free edge having two con- 

 cavities where the angular and the parietal lamellae approach 

 it ; its inner end curves downward a little, terminated on a very 

 low semicircular callous rim which bounds the cavity formed 

 by the posterior inflation of the basal crest. Upon this rim 

 stand two short, high oblique folds, upper and lower, converg- 

 ing towards each other inwardly. The lower palatal fold is 

 short and rather high. Externally the palatal folds are visible 

 as buff markings, the upper palatal and upper oblique fold 

 showing as a decurved band, the lower oblique fold and lower 

 palatal as indistinct spots (pi. 25, fig. 14). 



Length 1.95, diam. 1.18, aperture 0.73 mm.; 5% whorls 

 (type). 



Length 1.95, diam. 1.13, aperture 0.66 mm. Limahuli, fossil. 



Length 2.02, diam. 1.3 mm. Ekaula. 



Length 2, diam. 1.25 mm. ; 5% whorls. 



Length 1.9, diam. 1.25, aperture 0.6 mm. ; 5% whorls. 



Kauai: Hanakapiai (type loc.) ; Ekaula and Olokele 

 (Cooke) ; also fossil at Limahuli (Dole and Cooke). Type 

 11061 Bishop Museum ; paratypes 15575 Bishop Museum and 

 119449 A. N. S. P. 



This species is well distinguished by its short, compact 

 contour, numerous strong ribs, the absence of any trace of a 

 third or subbasal impression on the back, and by the strongly 

 developed apertural processes. 



L. thaumasm is closely related to L. cubana, and may prove 

 to be connected by intermediate forms. On comparison of 

 the type specimens there is no difference in color, sculpture 

 or convexity of the whorls, but cubana is clearly wider than 

 the shortest thaumasia at hand. In thaumasia of the same 

 length as cubana, 1.9 mm., there is nearly a half whorl more, 

 and the aperture is distinctly smaller. Its length, measured 

 vertically is slightly less than one-third that of the shell, while 

 in cubana it is decidedly more than that, contained 2^ times 

 in length of shell. There is no difference in the apertural 

 parts so far as visible in the mouth. 



