b STOMATELLID^E. 



An arrangement of Stomatellidse, including the characters of a 

 new genus and of several new species. By Arthur Adams, R. N., 

 F. L. S., etc. This paper was published in Proc. Zool. Soc. Lond. 

 1850, and Annals and Magazine of Nat. Hist, vii, 1851. 



Monograph of Stomatellinse, a subfamily of Trochidse. By A. 

 Adams, in Sowerby's Thesaurus Conchyliorum, vol. ii (1855). 



Monographs of Stomatella, Stomatia, Gena and Broderipia, by G. 

 B. Sowerby Jr., in Reeve's Conchologia Iconica, vol. xix, April, 

 1874. 



Synopsis of Genera. 

 Genus STOMATELLA Lamarck, 1819. 



Shell imperforate, spiral, orbicularly depressed ; spire elevated 

 but short, conic ; whorls rounded not plicate below sutures, .the last 

 forming the greater part of the shell ; surface spirally ribbed, 

 variegated ; aperture large, wider than long, pearly inside ; oper- 

 culum circular, multispiral, horny. Type, S. imbricata Lam. 



Subgenus SYNAPTOCOCHLEA Pilsbry, 1890. 



Shell oval, intermediate between Stomatella and Gena in contour ; 

 spire very short, sub-marginal ; surface spirally striated or decus- 

 sated ; aperture very large, longer than wide. Operculate. Type, 

 8. montrouzieri Pilsbry. 



Subgenus NIPHONIA A. Adams, 1860. 



Shell depressed-globose, thin, imperforate ; 'whorls rapidly increas- 

 ing ; aperture large, circular ; peristome duplicated, outer margin 

 thin, acute, ascending on the last whorl, inner margin thickened, 

 continuous with outer lip. (Ad.) Type, N. pulchella Ad. 



Genus PHANETA H. Adams, 1870. 



Shell imperforate, trochiform ; spire of few whorls, the last car- 

 mated, expanded ; base depressed ; aperture ample, rounded, an- 

 teriorly subsinuated, pearly inside; columella revolute, acute; per- 

 istome simple, straight. (Ad.) Type, P. everetti Ad. 



Borneo. 



A fluviatile mollusk. 



Genus STOMATIA (Helbling) Lamarck, 1801. 



Shell spiral, oblong or depressed orbicular ; spire prominent but 

 short ; surface tubercled or keeled ; whorls with a series of short 



