156 | Bulletin American Museum of Natural History [Vol. LIII 
Pseudancylus hamacenicus (Bourguignat) = Ancylus hamacenicus BoURGUIGNAT, 
1883, Ann. Sc. Nat. Zool., (6) XV, p. 84. Ancylus (Ancylastrum) compressus JICKELI, 
1874, Nova Acta Ac. Nat. Cur. Dresden, XX XVII, 1, p. 223, Pl. vu, fig. 26 (not 
Ancylus compressus Nyst, 1843). Near Mekerka on the Toquor River, Eritrea. 
UNCLASSIFIED ANCYLID 
“ Ancylus” ruandensis J. Thiele 
Ancylus ruandensis J. Tareue, 1911, ‘Wiss. Ergebn. D. Z. Afr. Exp. (1907-08), ’ 
III, p. 208, Pl. v, figs. 48 and 48a. | 
Lake Luhondo in Ruanda (type locality; Schubotz Coll.). 
“ Ancylus”’ vicinus J. Thiele 
Ancylus vicinus T. Tureie, 1911, ‘Wiss. Ergebn. D. Z. Afr. Exp. (1907-08),’ 
‘III, p. 208, Pl. v, fig. 49. 
Falls between Lakes Bolero and Luhondo, in Ruanda (type locality; Schubotz 
Coll.). 
“‘Ancylus’”’ tanganyicensis (EH. A. Smith) 
Plate XII, Figures 6 and 6a 
Ancylus tanganyicensis EK. A. Smrru, 1906, Proc. Zo6dl. Soc. London, I, p. 184, Pl. 
x, figs. 17 and 18. B. Wauxmr, 1924, ‘Ancylide of South Africa,’ p. 80 (note on denti- 
tion). 
oie, tanganyicensis EK. A. Smith. B. Wauxkemr, 1914, The Nautilus, XX VII, 
~ LEG: 
: Lake Tanganyika: Niamkolo, at the southern end of the Lake (type locality; 
W. A. Cunnington Coll.). 
Kasakaku Bay, Lake Tanganyika (Stappers Coll.). 
A small, regularly elliptical species with nearly central apex, which 
shows no trace of apical pit. It has a rather indistinct sculpture of radial 
striz crossed by concentric strie, giving a somewhat cancellated appear- 
ance. ‘The anterior slope is nearly straight, the posterior slightly concave 
near the summit, which is quite obtuse; side slopes straight. Sculp- 
ture of very fine, irregular but distinct radial strie. 
Length, 2.0 mm.; width, 1.55 mm.; altitude, 0.7 mm. 
The apical sculpture differs from that of Ferrissta by the presence of 
concentric striz; the radials are rather coarse and low. In some lights a 
cancellation reminiscent of Burnupia is seen. Walker states that the 
radula is very similar to that of Gundlachia equeefensis, and he believes 
that it belongs to that genus. 
SCUTIBRANCHIATA RHIPIDOGLOSSA 
Neritidze 
| Shell imperforate, globose or hemispherical, with short spire, or non-spiral 
somewhat limpet-like with marginal apex. Internal partitions of the shell resorbed. 
Aperture semi-ovate, entire, with acute outer lip; columellar region expanded, flat. 
