170 Bulletin American Museum of Natural History [Vol. LIII 
8. Shell very thin, almost wholly corneous, with wavy spots; the early whorls 
angular or subcarinate. Umbilicus perforate or vestigial; columella not 
calloused..... Sta aS PMR SEN Tt ite ne Noto be a eR Saulea Gray. 
Shell heavy, thick, not spotted; the early whorls not subcarinate; the peri- 
ostracum densely rippled-lineolate. Axis imperforate; columella heavily 
EE MUKOSU 1o)cX0 WACIME gen MISS an Gut ESA ee a Oe Afropomus Pilsbry and Bequaert. 
9. Shell heavy, globosely conic, imperforate; the columella strongly calloused; 
surface often spirally lirate. Operculum narrow. 
Subgenus Leroya Bourguignat. 
Shell thinner, lighter; the umbilicus either broadly open, perforate or closed; 
but the columella thin, not calloused. Operculum broad.............. 10. 
10. Shell longer than wide; the umbilicus very narrow, perforate or closed, without 
a bordering angle; all of the whorls convex, not angular. 
Subgenus Meladomus Swainson. 
Shell usually as wide as long or wider; umbilicus open, often bounded by an 
angle; whorls of the spire often angular.....Subgenus Lanistes, proper. 
Pomacea Perry 
_Ampullarius DENYs DE Montrort, 1810, ‘Conchyl. Systém..,’ IT, p. 242. Mono- 
type: Nerita urceus O. F. Miller. Not Ampullaria Lamarck. 
Pomacea Pmrry, 1811, ‘Conchology,’ letter-press to Pl. xxvim1. Type: Pom- 
acea maculata Perry = Nerita urceus O. F. Miller. 
Conchylium Cuvisr, 1816, ‘Le Régne Animal.,’ II, p. 426, comprising four sub- 
genera: Ampullaria, Melania, Phasianella, and Janthina. Type by present designa- 
tion: Bulimus urceus Bruguiére. 
Pomus H. and A. Adams, 1856, ‘Genera of Recent Mollusca,’ p. 346. Type P. 
urceus (O. F. Muller). 
Pomacea is the prevalent type found in the New World, but it 
is not represented in the Old World, unless by the groups Saulea and 
Afropomus. ‘These we are provisionally treating as genera; but if they 
prove to be longisiphonate, when the animals are examined, they may 
more justly be ranked as subgenera of Pomacea, with which they agree 
in character of the operculum. 
SAULEA Gray 
Saulea GRAY, 1867, Proc. Zool. Soc. London, p. 1000. Monotype: Helix vitrea 
Born. 
This group, which Dall ranks as a section of Pila, has a thin, wholly 
corneous operculum as in American Ampullariide. When the soft 
parts are known, it may very likely prove generically distinct and we 
provisionally give it generic rank. The operculum and shell of the type 
species are figured on Pl. XIV, figs. 2 and 3. 
The dry remains of a rotten animal washed out of a shell of S. vitrea 
furnished a few isolated teeth (Fig. 13a). The central has strongly 
sloping lateral margins as in Lanistes. It has five cusps, seen much 
