WATSON : ANATOMY OF HELICARION. Ill 



Subgenus Geanularion, Germain. 



Protoconch spirally punctate (excepting in H. suhsucculentus), 

 often having the appearance of being slightly tilted to one side ; 

 remaining whorls glossy, with little or no microscopical spiral 

 sculpture. Shell- lobes usually rather more granular than in the last 

 subgenus, the left broad and nearly always rounded, the right more 

 variable, but never ridged, often more or less concrescent with the 

 left. Medium projection of jaw present, but usually rather low. 

 Central and lateral teeth normal, marginals numerous, Epiphallus 

 bearing two rather small flagella, rarely reduced to one. Penial 

 sheath when present not extending to the retractor muscle. 

 Spermatheca usually spherical. Genital atrium not bearing a 

 dart-sac, which is either absent or takes the form of a hemispherical 

 protuberance at the junction of the vagina and oviduct. 



Known distribution : Equatorial Africa, from British East Africa 

 to the west coast, and extending northwards into the Sudan. 



succulentus, v. Marts. 

 stuhlmanni, v. Marts.^ 

 insularis, Thiele. 

 schubotzi, Thiele. 

 suhsucculentus, Pilsbry, 

 cryptophallus, n.sp. 

 columellaris, d'Ailly. 

 duporti, Germain (type). 

 pertenuis, d'Ailly. 

 issangoensis, Thiele. 

 maculifer (Pilsbry). 

 auriformis, Thiele. 



Subgenus Africarion, Godwin-Austen. 



Shell-lobes rounded, concrescent, with a dark band on the left 

 side. Median projection of jaw rather small, but prominent. Central 

 and lateral teeth normal, marginals not very numerous. Spermatheca 

 spherical. No flagella, epiphallus, or dart-sac. 



Known distribution : Abyssinia. 



pollens, Morelet (?).'^ 



^ The species referred to in this paper as H. stuhlmanni, v. Marts., is that 

 described as such by Thiele [DeuUch. Zentral-Afrika-Exped. (1907-08), vol. iii, 

 1912, pp. 194-195, pi. vi, fig. 64). But Thiele states that his examples 

 have neither the microscopical spiral stri» seen in the type-specimen, nor 

 the coarse furrows that von Martens describes as characteristic of his 

 species. Moreover, von Martens states that the animal is dark grey (in 

 alcohol), and that its right shell-lobe is triangular (Deutsch-Ost-Afrika, 

 vol. iv, 1897, p. 37), while Thiele describes the animal as of a light colour, 

 with rounded pallial lobes. It therefore seems possible that the form 

 described by Thiele is not identical with von Martens' species. 



' The Abyssinian form described by Godwin-Austen {Moll, of India, vol. i, 

 1883, pp. 154-6, pi. xlii) is at present, the only species known to belong to the 



