PARTULA, MARIANNE ISLANDS. 313 



The nodule on the parietal wall, shown in Lesson's figure 

 but not mentioned in the description, is a feature appearing 

 also in species of the Society, Fiji and Marianne groups. 

 The relationships of the species are obscure. I would not 

 venture to assign it to any of the subgenera. 



XIII. MARIANNE (Ladrone) ISLAND GROUP. 

 (Section MARIANNA n. sect.). 



Harmonia HARTMAN, Catal. Genus Partula, 1881, p. 13, 

 type P. gMa, Fer. (proec.). 



The shell is ovate or inflated with a small umbilicus and a 

 lip more or less thickened within; parietal wall plain or 

 bearing a very deeply placed callous nodule. Type P. gibba. 



Guam, the chief island of the group, is the only one which 

 has been collected on. 



109. P. GIBBA Ferussac. PI. 39, figs. 1 to 11. 



Shell conic-ovate, perforate, rather solid, striatulate, pellu- 

 cid, engraved longitudinally with equal lines, white or flesh- 

 colored, the spire acute, rose-red, the suture milk-white ; epi- 

 dermis thin, rufescent. Whorls 44/2 , 'the last swollen, gibbous, 

 larger than the rest. Aperture long-ovate, subquadrangular ; 

 peristome reflexed, broadly dilated, white. (Per.). 



Marianne Is.: Guam (Gaudicho, Quadras, Rush et al.) 



Partula gibba FER., Tableaux Systematiques des Animaux; 

 Mollusques etc., suive d'un Prodrome general pour tout les 

 Moll., etc. p. 66, (1821), and in Freycinet, Voyage autour du 

 Monde de FUranie et la Physicienne, Zoologie, p. 485, pi. 68, 

 f. 15, 16, 17. REEVE, Conch. Icon. pi. 3, f. 15. PFR., Monogr. 

 iii, 453 ; iv, 514 ; vi, 160 ; viii, 208 ; Conchyl. Cab. -p. 269, pi. 

 64, f. 9-14. Bulimus gibbus PFR., Monogr. ii, 69. DESK, in 

 Fer., Hist. p. 122, pi. 158, f. 19, 20. Helix gibba QUOY et 

 GAIM., Zool. Astrolabe ii, p. 113, pi. 9, f. 18-20. Partula 

 mastersi PFR., P. Z. S. 1857, p. 110; Monogr. iv, 513 (Guam). 



Ferussac's type of P. gibba was a small, short example. 

 His figure is copied (pi. 39, fig. 1). The last whorl is pale 

 yellowish-corneous, spire of a rather peculiar dull scarlet 



