A^e7i' Species of Aviastra. 29 



Section Heteramastra. 

 A. fletningi, n. sp. 



PL B. Fig. 7. 



Tlie shell is indistinctly rimate, sinistral, oblong-turrite, in 

 its fossil state whitish. The spire is elongate, faintly contracted 

 above, with slightly convex outlines. The embryonic whorls are 

 regularly and finely striate, the rest rather smooth with few dis- 

 tinct growth-wrinkles, slightly obliquely angled above the oblique 

 sutures from the penultimate to the neanic whorls. The last 

 whorl elongate, subcylindrical, tapering gradually to the base 

 and showing no trace of a supraperipheral angle. The aperture 

 is narrow, distinctly biangular, with its outer margin regularly 

 curved and furnished with a strong lip-rib. The columella is 

 straight with its outer margin closely appressed to the shell, except 

 at its base. The columellar fold is rather strong, subbasal in 

 position, subtransverse, terminatiug gradually near the margin of 

 the columella. 



Length 13.7, diam. 6.0, apert. 5.2 mm.; 634^ whls. (Holotype) 



East Maui : Pleistocene of Kanaio, about 2,000 feet elevation, 

 two miles east of Ulupalakua (D. Fleming). 



Holotype No. 41,989, paratypes No. 40,063, Bishop Museum. 



Only three specimens of this interesting species were taken 

 by Mr. Fleming. The type is perfect but the other two specimens 

 are quite badly broken. A. Jiemingi occupies a position between 

 A. Urva and A. hiitchinsonii and appears to be more closely related 

 to the former than the latter. It not only larger than A. l<zva but 

 is proportionally narrower and its surface is not so roughly striate, 

 besides the aperture is distinctly biangular. A. fle»ii)igi differs 

 from A. hutchinsonii by its more convex outlines, flatter more com- 

 pact and closer coiled whorls, narrower and biangular aperture, 

 etc. It does not seem to be in any way related to A. szibsoror 

 ainvahiensis, the latter belonging to the soror subseries. 



[247J 



