1927] Pilsbry-Bequaert, The Aquatic Mollusks of the Belgian Congo 251 
Hydrognoma GisTEL, 1848, ‘Naturgesch. Thierr. f. Héhere Schulen,’ p. 169. 
Substitute for Melania Lane 
Tiara HERMANNSEN, 1849, ‘Ind. Gen. Malac. ) I, p.576. Emendation of Thiara 
Type: Melania amarula Linneus. 
The typical species, M. amarula (Linneus), of Madagascar, the 
Comoros, Mauritius, and Réunion, occurs in East Africa as a subspecies 
coacta (Meuschen), which according to Germain (1921, ‘Faune Malacol. 
Iles Mascareignes,’ p. 362) is but little different from the type. It is 
found along the coast from Ugogo to Lourenzo Marques and Zululand 
(at Izezela, Umkomaas, and Amanzimtoti River; Connolly, 1915, Ann. 
South African Mus., XIII, p. 100). Tiara vowamica Bourguignat (1889, 
‘Moll. Afrique Equator.,’ p. 183) and Melania crenularis E. v. Martens 
(1860, Malakoz. Blatter, VI, p. 216) Germain lists as synonyms of 
coacta. 
MELANOIDES Olivier 
Melanoides OutviErR, 1804, ‘Voyage dans l’Empire Othoman,’ IT, p. 40, footnote. 
Monotype: Melanoides fasciolata Olivier = Nerita tuberculata O. F. Miller. 
Melania subgenus Striatella Brot, 1870, American Journ. Conch., VI, 2, Appen- 
dix, p. 290, for several species, including M. tuberculata (Miller); 1874, in Martini 
and Chemnitz, ‘Syst. Conch. Cab.,’ I, 24, Melaniaceen, p. 7; divides it into two sec- 
tions with M. corporosa Gould and M. tuberculata (Miiller) as respective types. In 
1885, Fischer (‘Manuel de Conchyl.,’ p. 701) gives M. tuberculata as example of 
Striatella and this species is here designated as the type. 
Melania section Eumelania RovERETO, 1899, Atti Soc. Ligustica Se. Nat., X, p. 
109. Substitute for Striatella Brot, 1870.1 
Pallarya P. Hesse, 1916, Nachrichtsbl. Deutsch. Malakoz. Ges., XLVIII, p. 124. 
Substitute for Striatella Brot, 1870.1 
Nyassia BourcuiIenaT, 1889, Bull. Soc. Malacol. France, VI, p. 5. Type by 
present designation: Melania nodicincta Dohrn. 
Nyassella BoURGUIGNAT, 1889, op. cit., VI, p. 17. Type by present designation: 
Nyassella smitht Bourguignat. 
Micronyassia BouRGUIGNAT, 1889, op. cit., VI, p.24. Type by present designa- 
tion: Melaniaturritispira E. A. Smith. 
Nyassomelania BouRGUIGNAT, 1889, op. cit., VI, p. 30. Type by present desig- 
nation: Nyassomelania leia Bourguignat. 
Shell never very large or heavy; long and slender, with both axial and spiral 
sculpture, at least in the early neanic stage, sometimes spinose along the upper part 
of the whorls. Aperture ovate, the peristome somewhat sinuous, the inner lip not 
calloused. Operculum ovate, paucispiral, the nucleus near the baso-columellar margin, 
the spiral figure very small. 
Mantle having a row of digitiform processes near its margin. Radula relatively 
very small. Central tooth short and wide, with numerous (usually 9 to 11) denticles 
anda plain body. Laterals with numerous denticles, the body with a median convex- 
1This new name was unnecessary since Sériatella Brot, 1870, is not preoccupied by Striatella aerdh, 
1832, the latter being a genus of plants (Diatomacez). 
