224. Bulletin American Museum of Natural History [Vol. LIII 
Fig. 22. Lobogenes michaelis Pilsbry and Bequaert. Head, both sexes. 
LOBOGENES, new genus 
Shell with the general form of Amnicola; outer lip thin, produced forward in a 
broad, median lobe; columella heavily calloused. Operculum thin, wholly corneous, . 
paucispiral with nucleus at about the lower fourth. 
fl Penis (Fig. 22) very large, dagger-shaped, abruptly widened at the base of attach- 
ment. Radula about as in Paludestrina or Bythinella viridis, the central tooth with 
single basal denticles situated high on the margins. Formula of denticles eae 
Type: Lobogenes michaelis Pilsbry and Bequaert. 
Fig. 23. Lobogenes lmichaelis Pilsbry and Bequaert: a-b, type; c-d, two para- 
types. Kimilolo River. | 
ee 2 
This group has dentition entirely like the slender paludestrinids of 
Europe and America, the denticles being much more numerous on the 
outer than on the inner marginal, and the central tooth with single 
basal denticles. It differs from all the paludestrinids by the heavily 
calloused columella, like that of Lathoglyphus. The lobed outer lip 
reminds one of some of the species of the South American genus Potamo- 
lithus. | 
