112 PKOCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



Subgenus Gymnarion, Pilsbry. 



Protoconch smooth, or more usually spirally punctate (though 

 apparently on a rather smaller scale than in Granularion) ; remaining 

 whorls very finely microscopically granulate, except on the base. 

 Shell-lobes narrow, separate, and usually quite small. Median 

 projection of jaw prominent. Central and lateral teeth normal, 

 marginals variable in form but never very numerous. Epiphallus 

 present, but flagella absent. Penis ending in a slight knob, into 

 which the epiphallus enters and the retractor muscle is inserted. 

 Spermatheca usually oval, with a comparatively short duct. 

 Genital atrium often bearing an elongated non-muscular amatorial 

 organ. 



Known distribution : Equatorial Africa, from Uganda to the 

 west coast, and extending in a southerly direction into Rhodesia and 

 Portuguese East Africa south of the River Zambesi, which is much 

 further south than the other subgenera are at present known to 

 extend. 



pUcatulus, V. Marts. 



aloysii-sabaudice, Poll. (type). 



sowerhyanus (Pfeiiier). 



gomesianus (Morelet). 



welwitschii (Morelet), 



nyasanus, Smith. 



masul'uensis, Smith. 



medjensis, Pilsbry. 



Further investigation will probably show that this group should 

 be separated generically from Zonitarion and Granularion, and just 

 possibly from Africarion also ; and it will almost certainly have to 

 be subdivided into two or three subgenera or sections. The species 

 here placed in the subgenus Granularion also appear to belong to 

 two or three different sections, but so little is known about their 

 anatomy that it is not yet possible to say how they should 

 be classified. Pilsbry has well said that at present most of the African 

 species of Helicarion form a " nearly meaningless mass of materials 

 which nobody can utilize until the descriptive work is all done over 

 from a different standpoint ". 



subgenus Africarion, and its identification with H. x>allens, Morelet, is still 

 not quite certain. The two Indian species which Godwin-Austen at one time 

 also placed in Africarion differ considerably from any of the African forms, 

 and are now placed in the genus PscHdaustenia, Cockerell (see Blanford and 

 Godwin-Austen, Fauna of Brit. India, Moll. Testacellidce and Zonitidm, 

 1905, pp. 206-9). It is possible, however, that H. subangulatus, v. Marts., 

 from the Semliki Valley near Mount Ruwenzori, may prove to belong to this 

 subgenus,, but at present its anatomy is unknown. 



