182 Tra7\sactions of the Royal Society of South Africa. 



into the buccal retractor and the left tentacular retractor, and the latter 

 again divides into branches going to the upper and lower left tentacles and 

 to the front of the head. The asymmetrical origin of the buccal retractor 

 is probably not a primitive feature, as this muscle is innervated by a 

 symmetrical pair of nerves, that to the right side of the retractor arising 

 from the right cerebral ganglion, and that to the left side from the left 

 ganglion. 



Although the outer skin of the upper tentacles seems to be devoid of 

 pigment, the retractors of these tentacles are pigmented in the usual manner, 

 which does not appear to be the case in the genus Subulina. 



Reproductive organs (PI. V, fig. 15).— The follicles of the hermaphrodite 

 gland are embedded in the posterior division of the liver. The hermaphro- 

 dite duct is but slightly swollen and convoluted. No vesicula seminalis 

 was found, unless it is represented by a slightly enlarged and abruptly 

 convoluted portion of the duct close to the albumen gland. The uterine 

 part of the common duct is greatly swollen by the presence of the relatively 

 large embryos within it. One of these embryos is shown in fig. 9. They 

 measure about 3|x2 mm., and three of them were found in the uterus of 

 one adult snail, and five in another. As they were not enclosed in any 

 egg-shells, there can be little doubt that this species is viviparous. 



The receptaculum seminis or spermatheca is rather small, and lies close 

 to the common duct towards its anterior end ; it is borne on a slender 

 receptacular duct of moderate length. The free oviduct is very short, but 

 the vagina is decidedly long, though rather narrow. The genital atrium or 

 vestibule is very short. The vas deferens is slender, and enters the hinder 

 end of the penis beside the insertion of the penial retractor. There is no 

 distinct epiphallus. The penis is rather narrow near the genital atrium, 

 but is broad posteriorly ; and although it is of no great size, it is not nearly 

 so small as in Subulina octona* 



The spermatozoa have small heads, and very long slender tails, with a 

 spiral filament or flange near the anterior end (PI. V, fig. 12). 



Genus Curvella Chaper, 1885. 

 Curvella nyasana Smith, 1899. 



1899. Curvella nyasana Smith, P.Z.S., p. 588, pi. 33, fig. 44. D.F. 



Hah. L. Marques. District N. of Macequece, 4500 ft. ; Mtisherra K. 

 Valley (Cressy). 



This species was described from Mt. Chiradzulu, other Nyasaland 

 localities being Zomba, Masuku Plateau, and the Nyika Eange. The series 



* See Wiegmann, Beitrage z. Anat. d. Landschnecken d. Indischen Archipels (in 

 Zool. Erg. Niederlandisch Ost-Indien, vol. iii.), 1892, pi. xvi, fig. 3. 



