322 Bulletin American Museum of Natural History [Vol. LIII 
Melania damoni BE. A. Smith. PEuseneer, 1886, Bull. Mus. Hist. Nat. Belgique, 
IV, p. 108. 
Paramelania (Bourguignatia) imperialis Giraud. E.v. Martens, 1897, ‘Deutsch 
Ost Afr., [V, Beschalte Weichth.,’ p. 207. 
Paramelama imperialis Giraud. Marte, AND DavuTzENBERG, 1899, Journ. de 
Conchyl., XLVII, p. 178. 
Paramelania imperialis var. guillemer MARTEL AND DAvuTZENBERG, 1899, Journ. 
de Conchyl., XLVII, p. 178, Pl. viu, fig. 23 (Mpala). 
Paramelania imperialis var. mpalaensis MARTEL AND DAUTZENBERG, 1899, 
Journ. de Conchyl., XLVII, p. 180, Pl. vit, fig. 24 (Mpala). 
Pyrgulifera damonit EH, A. Smith. C. A. Wurtz, 1881, Nature, XXV, p. 102; 
1882, Proc. U. S. Nat. Mus., V, p. 98, Pl. 11, fig. 13. Tauscu, 1884, Sitz. Ber. Ak. 
Wiss. Wien, Math. Naturw. K1., XC, Abt. 1, p. 61, Pl. 1, fig. 4. 
Lake Tanganyika: originally described from that lake without more definite 
locality (Damon Coll.); Mpala, on the southwestern shore (Giraud Coll.; Guillemé 
Coll.); Tembwe and Mrumbi on the western shore at a depth of 30 to 40 fathoms; 
Mshale, on the northeastern shore at a depth of 25 fathoms; also at the southern end 
(W. A. Cunnington Coll.); on the western coast (Guillemé Coll.). 
Stappers dredged this species at a number of places: Bay of Kilewa; off Uvira; 
bay of Kasakalawe; delta of the Ruzizi River; near the mouth of the Sambala River; 
between the Moba and the Lobozi Rivers; and off Tulo. Hedley found it on the 
beach at Albertville. 
a b Cc 
Fig. 67. a-c, Paramelania (Bythoceras) iridescens (Moore), At b, a specimen 
from Kilewa. 
Subgenus ByrHoceras J. E. S. Moore 
Bythoceras J. Hi. S. Moors, 1898 (March), Proc. Roy. Soc. London, LXII, p. 
452; 1898 (July), Proc. Malacol. Soc. London, ITI, 2, p. 98. Monotype: Bythoceras 
tridescens J. E. S. Moore. 
According to E. A. Smith (1906, Proc. Zool. Soc. London, I, p. 182), 
there seems to be very little in the character of the shells, opercula, 
and radule to separate this from Paramelania. Moore states that the 
