262 Bulletin American Museum of Natural History [Vol. LIII 
Melanoides wagenia, new species 
Plate XXII, Figure 14 
Stanleyville, from a brook near the falls of the Congo River; very 
abundant (H. Lang Coll.). 
The shell is much like M. admirabilis (E. A. Smith) of Lake Tanganyika. The 
spire, of weakly convex whorls, tapers regularly. Color deep olive-buff when cleaned 
of the blackish coating. Sculpture of regular axial ribs (about 20 on the penult 
whorl), which curve back a little below the suture, then forward and fade out at the 
periphery, the base of the last whorl having about six low spiral cords wider than their 
intervals. Sometimes one of these cords appears above the suture on the spire. 
The aperture is ovate, the outer lip thin, sinuous, curving forward below. The colu- 
mella is moderately thickened. 
Length, 26.0 mm.; diameter, 8.5 mm.; length of aperture, 8.7 mm.; 6 whorls 
remaining. Type. | 
Length, 22.0 mm.; diameter, 8.0 mm.; length of aperture, 7.7 mm.; 544 whorls 
remaining. 
Length, 22.5 mm.; diameter, 8.0 mm.; length of aperture, 7.3 mm.; 6 whorls 
remaining. 
This snail is extremely abundant and was collected by hundreds. 
It resembles M. admirabilis in sculpture-pattern, but is always smaller; 
the ribs much more numerous and they are not cut by a spiral impression 
a short distance below the suture, as in the Tanganyika shell. 
Variation is often toward weakening or obsolescence of the ribs and 
the basal spirals on the last whorls in old individuals. Among hundreds 
looked over, none was found having the color markings of the following 
race. 
Melanordes recticosta (v. Martens), from Angola, appears from the 
description somewhat related, but it is broader, with rather straight 
ribs and fewer. basal spirals. 
While this species and M. admirabilis have the sculpture of the 
subgenus Sermyla, they differ by the shape of the shell and aperture; 
we believe that there is no direct relationship. The sculpture of these 
African species is readily derivable from the tuberculata pattern, and 
in the neanic stage, described under M. w. tshopoicola, it resembles 
closely the pattern of M. anomala (Dautzenberg and Germain). 
Melanoides wagenia tshopoicola, new subspecies 
Plate XXII, Figures 15 and 16 
Sandbanks of the Tshopo River, near Stanleyville, in company with 
M. kisangant (H. Lang Coll.). 
The shell has the shape of M. wagenia, but differs in sculpture; the axial ribs are 
weaker and nearly straight; on the last whorl they are very weak or (in large speci 
