1917.] NATURAL SCIENCES OF PHILADELPHIA. 209 



Moomomi, on the north coast of western Molokai, type and many- 

 other specimens No. 117054, A. N. S. P., collected by Pilsbry, 1913. 



The umbihcus and the groove below it are larger than in other 

 Hawaiian species. The shell is thinner than that of P. variahilis or 

 P. hryani. 



The specimens vary in pattern, but nearly all were bleached. 



Phasianella thaanumi n. sp. PI. XV, figs. 12, 14. 



The shell is very thin, perforate, short, obliquely conic, the spire 

 short, somewhat attenuate, last whorl very rapidly enlarging. Surface 

 smooth, pale olive buff, translucent, with four indistinct, narrow 

 whitish bands on the latter part of the last whorl, where there are 

 also some very faint brownish flecks. 



- The very large and decidedly oblique aperture is subrotund, but a 

 little longer than wide. The outer lip is well expanded. Columella 

 is narrowly expanded, thin, regularly arched, and there is a forwardly 

 salient angle where it joins the basal lip. The operculum is olive- 

 buff, strongly convex and smooth externally. 



Length 2.1, diam. 1.8, longest axis of aperture 1.35 mm. 



Hilo, Hawaii, D. Thaanum. Type and paratype No. 117053> 

 A. N. S. P., from No. 8393 of Mr. Thaanum's collection. 



This species is very distinct by the projection of the peristome at 

 the foot of the columella. The rapidly enlarging whorls and marked 

 expansion of the lip are also characteristic. The surface has a thin 

 calcareous incrustation, unlike the clean, glossy appearance of most 

 Phasianellas. 



ALCYNA. 



Alcyna contains shells similar to Phasianella except that the 

 columella has a strong tooth. The operculum is not yet known. 

 So far as we know, the greatest development of Alcyna is on the 

 Hawaiian shores, where six species have been found. Four of these 

 were described by W. H. Pease, 1860- '69. As none of them has 

 been fully characterized, and only one figured, I am giving new 

 figures of all but one, A. striata Pease,^ the specimens of which could 

 not be found in the Pease collection, being either lost or misplaced. 



Mr. Kuhns dredged A. kuhnsi in 25 to 50 fathoms. Four species 

 collected by the writer were found in strand debris, on the shores of 

 Oahu, Molokai and Kahoolawe. 



1 AlcijJM striata Pse., Amer. Jour, of Conch., V, p. 70; Man. of Conch., X, p. 182, 

 reprint of original description. 



