the South-African Stenogyrince. 2d I 



placed at present ; but while so much uncertainty exists 

 regarding the habits and anatomy of many of the animals, I 

 think it inadvisable to further complicate matters by a possibly 

 erroneous reclassification. 



In the following notes, every shell of which I have counted 

 the whorls and taken the measurements has been so dealt 

 with lying flat on its back, aperture upwards. The very 

 important measurement which I call length of last whorl is 

 that taken from the extreme base of the aperture to the centre 

 of the suture immediately above it. 



I have usually taken as type the largest specimen available. 

 Nearly all Stenogyrinse begin to reproduce before attaining 

 full size, though, as a general rule, the presence of eggs in 

 the ovary may be taken as proof that the shell is at least 

 two-thirds grown. Some species, however, certainly begin 

 to reproduce before their shells attain half the size of typically 

 large specimens. Whether these individuals would, in ordi- 

 nary course, continue growth to large dimensions, or whether 

 their growth at the time of reproduction is almost completed, 

 has not, I believe, yet been determined. 



In the present survey I have taken as my northern geogra- 

 phical limit the Tropic of Capricorn, thus excluding the genus 

 Subulina, which is a tropical rather than a South- African 

 form. 



With the exception of Euonyma unicornis, the types of all 

 the new species have been presented by Messrs. Ponsonby, 

 Farquhar, or myself to the British Museum. 



Reference List, with Notes. 



Family Achatinidae. 



Subfamily Stenoqyrinjs. 



Genus Euonyma, M. & P., 1906. 



(Ann. & Mag. Nat. Hist, xviii. p. 316.) 



Proposed by Melvill and Ponsonby for the sinistral form 

 Iceocochlis, and extended by Pilsbry to embrace the South- 

 African group of " rather large, slender Stenogyroid snails " 

 which he considers to differ from Opeas chiefly in their larger 

 size and general aspect, and to be kept separate from Steno- 

 gyra solely by the diverse geographical distribution, Stenogyra 

 in the restricted sense comprising only tropical American 

 species. 



It rests with some future student of anatomy to decide 



17* 



