268 PROCEEDINGS OF THE MALACOIOGICAL SOCIETY. 



SOME NOTES ON THE NON-MARINE MOLLUSCAN FAUNA OF THE 

 HAWAIIAN ISLANDS, WITH DIAGNOSES OF NEW SPECIES. 



By C. P. Ancet. 



£ead IZth January, 1899. 



(PLATES XII AND XIII, Figs. 8, 16, 20.) 



1. Endodonta (Thaitmatodon) nuda, n.sp. PI. XII, Pig. 1. 



Testa articularis, rotuliformis, depressa, aperte umbilicata (umbilicus 

 sat magnus, circularis, tertio diametri minor), micans, lutea, strigis 

 fuscis in ultimo anfractu fulguratis, ijiferne evanidis amoene picta, 

 costulis lamellosis confertis, circa umbilicum magis approximatis 

 exarata. Spira plana, anfractus 5 convexi, angusti, lente accre- 

 scentes, sutura impressa; ultimus cylindricus, baud deflexus. Aper- 

 tura vix obliqua, rotundato-lunata, lamellis 2 volventibus in pariete 

 (supera majore) et palatalibus 5 minus prolongatis, sequidistantibus 

 obstructa. Peristoma simplex, acutum, marginibus remotis. Diam. 3, 

 alt. 1'25 mm. 



Hah. — Olaa, Central Hawaii (M. Tbaanum). 



This is a very distinct little form ; the armature of the aperture 

 resembles that of E. contorta, Per., of Oahu, but the shell is not 

 hirsute, though quite fresh. 



2. MicKocxsTis SEEicANS, u.sp. PL XII, Fig. 5. 



Testa orbicularis, depressa, imperf orata (in loco perforationis minute 

 foveata), tenuis, pellucida, Igete cornea, nitens, supra subsericeo- 

 micans. Spira obtusa, vix elata, valde depressa, anfractus 4^, 

 convexiusculi, lente accrescentes, lineis incrementi inconspicuis, sutura 

 superficiali divisi; ultimus mediocriter altus, initio (ad insertionem 

 superam aperturee et supra peripheriam) obtuse angulatus, postea 

 rotundatus, infra depresso-convexiusculus. Apertura lunata, fere 

 recta, margine externo cum basali regulariter curvato ; columella 

 minute incrassata. Diam. maj. 7*33, min. 6'5 mm. ; alt. 4'25 mm. 



JSai. — Olaa, Central Hawaii (Thaanum). 



This is very distinct from its nearest ally, 31. cicercula, Gould, 

 which is found on a different part of Hawaii. It is more depressed 

 above, has 4-J-, not 5 whorls, and a somewhat silky lustre on its upper 

 surface. 



3. Ptekodiscus petasus, n.sp. PI. XII, Fig. 4. 



Testa latissime et perspective umbilicata, sublenticularis, tenuis, 

 luteo-fusca, concolor, vix nitens, ruditer et confertim rugoso-striata, 

 striis lamellosis. Spira late conoidea, lateribus subconcavis, vertice 

 prominulo, obtusiusculo. Anfractus 5, fere plani, sutura lineari et 



