258 LYEOPUPA. 



On Lanai, as on Kahoolawe, this is the only Lyropupa known 

 to exist. 



While some slight insular differentiation has been noted 

 above, it is too variable to allow us to speak of races on the 

 different islands. Cases of similar distribution have been re- 

 corded in Leptachatma and the Tornatellinidae. 



L. kahoolavensis puukolekolemis P. & C., n. subsp. PI. 26, 

 figs. 9, 12. 



Recent specimens from Puukolekole, Molokai, collected by 

 Thaanum, are tawny or a little darker, irregularly sculptured, 

 numerous riblets being intercalated on the lower half of the 

 last whorl or two. The sinulus is more distinct than in Oahuan 

 perlonga as the upper palatal fold emerges nearly to the edge. 

 The lower palatal fold is a rather large callous pad, as seen 

 in the mouth. It has a lower connection backward with the 

 high tubercle below the inner end of the upper palatal. There 

 is a quite weakly indicated basal callus, and the usual tubercle 

 deep within. 



Length 2.1, diam. 1.2 mm.; 5 whorls (fig. 9). 



Length 2.25, diam. 1.25 mm. ; 5 whorls. 



This form has a lower palatal fold intermediate in develop- 

 ment between kahoolavensis and perlonga, but the sculpture 

 is practically as in the latter. It is more specialized than the 

 fossil kahoolavensis, as the connection between the anterior 

 and posterior portions of the lower palatal is low, and except 

 in certain lights the fold appears interrupted. 



16. LYBOPUPA PERLONGA (Pease). PL 23, figs. 1-6, 13, 14; 

 pi. 24, figs. 6, 7. 



"Shell elongate, cylindrical, rimate-perf orate, dextral, pale- 

 straw color, longitudinally thread-like costate, the costae 

 oblique, remote, flexuous; spire obtuse; suture impressed; 

 whorls 5, somewhat flat, the last concentrically sulcate at the 

 middle, indented near the base; the base compressed, rotund- 

 ate-angulate about the umbilicus; aperture somewhat quad- 

 rangular, slightly extended, contracted at the base, rotund, pos- 

 teriorly bilamellate, the upper lip sinuous above, unilamellate ; 



