SPECIES OF ZONITIDA: FROM EQUATORIAL AFRICA, 803 
marked with radiate arcuate growth-plications and discoloured 
with a purplish tinge in the circum-umbilical region ; perforation 
narrow, deep, slightly overhung by the outward expansion of the 
columella; columella triangularly outwardly expanded above, 
descending in a gentle curve, the margins slightly converging, 
receding below; aperture subovate. 
Alt. 11, diam. maj. 12°5, diam. min. 10°25 mm. 
Aperture: alt. 6, diam. 5-75 mm. 
Hab. Uarogi Hills, British Hast Africa, at an altitude of 
between 6000 and 7000 feet. (A. Blayney Percival.) 
MIKENOBLLA NEGLECTA, sp. n. (PI. II. fig. 27.) 
Shell globosely turbinate, narrowly perforate, thin, unicolorous, 
pale yellowish brown; whorls 53, regularly increasing, marked 
only with slightly arcuate, transverse growth-plice ; base of shell 
convex; umbilicus very narrow, almost covered by the outward 
reflexion of the columella; columella broadly outwardly reflexed 
above, very narrowly so below; aperture subovate. 
Alt. 11, diam. maj. 13°25 (nearly) mm. 
Aperture: alt. 7-5, diam. 6°5 mm. 
Hab. Kiduha, $.W. Uganda. (Robin Kemp.) 
URGUESSELLA, gen. nov. 
Shell perforate, thin, corneous, depressed, hirsute, the last 
whorl descending rather rapidly in front. 
Genotype: U. urguessensis Preston. 
The following two species should undoubtedly be included in 
Urguessella :— 
Trachycystis nigrotincta Preston, from British Hast Africa, Rev. 
Zool. Africaine, vol. i. p. 325, pl. xvii. fig. 9. 
T. fusco-olivacea Smith, from Nyassaland, Proc. Zool. Soe. 
London, 1899, p. 585. 
URGUESSELLA URGUESSENSIS, sp. n. (PI. III. figs. 25, 25 a, 25 6.) 
Shell perforate, turbinate, with subplanulate spire, yellowish 
brown, covered with a hirsute periostracum, the hairs being about 
one millimetre in length, yellow in colour, placed at a moderate 
distance apart and arranged in very oblique rows; whorls 43, 
regularly increasing, the last descending in front; suture 1m- 
pressed ; base of shell somewhat convex ; umbilicus rather narrow, 
deep; columella triangularly outwardly expanded above, de- 
scending in a rounded curve; labrum white, thin, very narrowly 
outwardly expanded and reflexed; aperture somewhat rect- 
angularly ovate, on the parietal wall; just without the aperture, 
where the hairs no longer appear, the surface of the shell is seen 
to be marked with transverse pustulous riblets. 
Alt. 5:25, diam. maj. 9°25, diam. min. 8 mm. 
Aperture: alt. 3°75, diam. 4 mm. 
Hab. Urguess, British East Africa. (A. Blayney Percival.) 
