1927] Pilsbry-Bequaert, The Aquatic Mollusks of the Belgian Congo 225 
Lobogenes michaelis, new species 
Text Figure 23 
At the source of the Kimilolo River near Elisabethville (Michael 
Bequaert Coll.). 
The shell is imperforate, rather solid, ovate-conic with the apex obtuse; ecru- 
olive in color. The whorls are strongly convex below the suture, then rather weakly 
convex, the last whorl strongly convex also at the periphery. The surface is elossy, 
marked with low, forwardly-arched growth lines and having fine, very shallow spiral 
striation, which becomes subobsolete on the last whorl (and sometimes is nowhere 
noticeable). The aperture is about half the total length, ovate and slightly oblique. 
The outer lip is thin, its middle part produced forward in a conspicuous lobe. The 
columella is concave, very much thickened by a heavy white callus. 
Length, 3.8 mm.; diameter, 2.9 mm.; length of aperture, 2.0 mm.; 444 whorls. 
Q. 
Length, 3.0 mm.; diameter, 2.3 mm.; length of aperture, 1.8 mm.; 4 whorls. 
3. Type. 
The male measured may not be adult. It was the 
only one found in 8 specimens opened. 
The lobe of the lip is developed in the neanic 
stage, being distinct in a shell 1.8 mm. long. Columella 
and closed umbilicus are as in the adult stage. 
Lobogenes spiralis, new species 
Text Figure 24 . 
At the source of the Kimilolo River near Elisabeth- Fig. 24. Lobo- 
ville (Michael Bequaert Coll.), genes spiralis 
Pilsbry and 
Bequaert. Type. 
Kimilolo River. 
The shell is more slender than L. michaelis, slsteactly per- 
forate, and very distinctly striate spirally, the strie coarse. The 
aperture is smaller. The curvature of the lip is less pronounced, 
and the columella less heavily calloused. 
Length, 2.8 mm.; diameter, 2.0 mm.; aperture, 1.40 mm.; 4 whorls. Type. 
Rate 8 a si Va ane - 1.75 “ 436 whorls. 
INCERTZ SEDIS 
Tomicuia Benson 
Tomichia Benson, 1851, Ann. Mag. Nat. Hist., (2) VII, p. 378. Monotype: 
Truncatella ventricosa Reeve. 
This genus has been placed in the Prancatellidee but the external 
characters of the animal as described by Benson, and the radula, ex- 
amined by Troschel, Thiele and ourselves, show this classification to be 
erroneous. 
The teeth resemble those of Synceride and Amnicolide in general 
form. The central tooth (Fig. 25) has a long reflection with 213 
