Continued studies on the streptaxids among the terrestrial molluscs of Malaŵi have revealed the existence of various undescribed species of Gulella L. Pfeiffer, 1865, sensu lato. Recently additional material has been received from Messrs H.P.M.G. Menkhorst (Krimpen a/d IJssel) and W.N. Gray (Brixham, U.K.), who donated their collections to the Leiden Museum (now NCB Naturalis, abbreviated RMNH). Valuable Malaŵi material in the Museum of Comparative Zoology/Harvard University (abbreviated MCZ), collected by Arthur Loveridge in the years 1948-1949, has also been made available for examination. Material for comparison was kindly loaned by the Musée Royal de l’Afrique Centrale (Tervuren, Belgium, abbreviated MRAC).
This is an opportunity to publish the descriptions of four new species of Gulella s.l. The genus is used here in its broadest sense – the time has not yet come to subdivide it because too few anatomical data are available (there are as yet no published data on the anatomy of the type species) and it would be sensible to wait for more molecular data – all reasons why the species below are simply described as new taxa in Gulella s.l. Attention is drawn to Rowson et al. (2010: 93-94), who already have started to unravel this problem.
The abbreviation l/d stands for the ratio length/major diameter as an indication of the shape of the shell; l/d values are calculated from micrometer readings before conversion to mm.