Beference List of South African Non-marine Mollusca. 145 



270. TRACHYCYSTIS RIVULARIS (Krauss). 



1848 Helix rivularis, Krs., Siidafr. Moll. p. 77. pi. 4, f. 25. D.F. 

 ,, Pfr., Zeitschr. f. Malak. v. p. 114. D. 



1853 ,, ,, Mon. Hel. iii. p. 110. D. 



1874 Jick., Fauna N.-O.-Afr. p. 59. N. 



1887 Helix (Pella) rivularis, Krs., Tryon, Man. of Conch, iii. p. 107. 



pi. 20, f. 85-87. D.F. 

 Type in Stockholm Museum. 

 Hob. NATAL. Source^of Mooi Kiver (Wahlberg). 



var. DENSESTRIATA, nov. [S.A.M.] 



Shell small, rather depressed, umbilicate, thin, bright fulvo-cor- 

 neous, covered on both sides with close, prominent, regular, curved, 



1 

 X 3 



1. Trachycystis rivularis, Krs. (Type). 



2. ,, var. densestriata, Zwart Kop. 

 3! !', ,, Pietersburg. 

 4. ,, ordinaria, M. & P., Bloemfontein. 



5_ ;) ,, lirate var. , Kustfontein. 



transverse strige. Whorls 4^, rounded, gradually increasing. Suture 

 impressed. Aperture lunate, descending a little in front ; peristome 

 thin, simple ; columella weak, concave, margin slightly reflexed, but 

 in no way covering the umbilicus, which, though not wide, is deep, 

 extending to the apex. 



