322 COCOS ISLAND NESOPUPAE. 



oval, hardly oblique, slightly diagonal, lip-insertions distant,, 

 hardly converging. There is no trace of an angular lamella ; 

 parietal lamella very strong, upright, oblique, slanting out- 

 ward; columellar lamella rather strong, deeply seated, hori- 

 zontal, and perpendicular to the inner margin of the colu- 

 mella; lower palatal fold short, lamella-like, rather deeply 

 seated; upper palatal nearly equal and parallel to the lower, 

 but not so deeply placed. Peristome expanded, its outer mar- 

 gin very thin, membranous, the inner margin slightly thick- 

 ened. Length 1.4, diam. 0.98, apert. (diag.) 0.62 mm. 



Kauai: Hanapepe falls, on Trichomanes (Heller). Type 

 11078, paratype 20176 Bishop Museum. 



This most interesting little species was found by Mr. Forbes 

 on mounted fern specimens collected by Heller, and now in 

 the Bishop Museum herbarium. It is represented by two speci- 

 mens which agree very closely, though one of them is slightly 

 broken near the summit. This species was at first considered 

 a not quite fully developed P. thaanumi. Comparison with 

 nearly adult specimens of thaanumi, shows that the angular 

 lamella is present in that species before the peristome is at 

 all thickened. P. alloia is easily distinguished from P. singu- 

 laris by its blunter summit, shorter and broader outline and 

 fewer whorls. 



II. Cocos ISLAND SPECIES. 

 Section Cocopupa P. & C., n. sect. 



The shell is minutely pitted with very little striation, the 

 teeth typical for Nesopupa except that the inner end of the 

 columellar lamella does not turn downward; last whorl not 

 distinctly furrowed back of the lip. 



Cocos Island, in the Pacific about 550 miles southwest of 

 Panama, has several species which have been referred to 

 Ochroderma, a genus of the Caroline Islands ; but this relation- 

 ship has not been fully established by anatomical comparison 

 (see Vol. XVIII, p. 325). In the Galapagos Islands, however, 

 there is a truly Polynesian snail, Tornatellides chathamensis 

 (Vol. XXII, 201) ; so that the occurrence of the Polynesian 



