Mr. E. A. Smitli on African Mollusca. 319 



Specimen a is oval, more pointed behind than in front, 

 having the ventral and dorsal margins about equally curved. 

 On the other hand, example b is elongate, with the lower 

 margin quite straight along the middle, and, the valves being 

 somewhat pinched or compressed at that part, it has an 

 almost incurved appearance. 



2. Unio Verreauxi (Charpentier), Kiister. 



Unto Verreauxi, Charpentier, MSS., Kiister, Conch.-Cab. p. 150, pi. xliii. 

 %.6. 



Hob. Soutenthal Valley, Cape of Good Hope. 



I have not as yet seen a specimen sufficiently like the 

 figure of this species to determine whether it is really distinct 

 or not from U. coffer^ although there is every probability that 

 it will eventually prove to be merely a large broad form of it. 

 It most resembles specimen a of the variety natalensis 

 already described, but differs from it in being a little broader 

 posteriorly and in having the hinge-line straighter and more 

 raised at the hinder end. The fine lines mentioned by Kiister 

 as radiating from the umbones downwards are also traceable 

 more or less in most specimens of all the varieties of U. caffer 

 when regarded in certain lights. 



3. Unio kunenensts, Mousson. 



Unio kunenensis, Mousson, Journ. de Conch. 1887, p. 300, pi. xii. 

 tig. 10. 



Hub. A tributary of the Kunene or Cunune River, North 

 Ovambo or Ovampo, South-west Africa. 



This species, although found rather far north, may be classed 

 with the South-African species in contradistinction to those 

 found in the north, west, east, and central parts of the con- 

 tinent. 



It is quite different from the species already discussed, 

 having the surface for the most part ornamented with angular 

 wrinkling or corrugation. 



4. Mutela Wahlberji, Krauss. 



Irtdina Wahlberf/i, Krauss, Sudafr. Moll. p. 19, pi. ii. fig. 1. 



Spatha JVahlheryi, Clessin, Conch.-Cab. ed. 2 {Anodonta &c.), p. 187, 



pi. Ixiii. fig. 1. 

 Spatha natalensis, Lea, Proc. Acad. Nat. Sci. Philad. 18G4, p. 113 ; id. 



Journal, vol. vi. p. 04, pi. xx. fig. 58; Clessin, /. c. p. 189, pi. Ixu. 



figs. 7, 8. 

 Hob. Monkey River, a branch of the Limpopo [Krauss) ; 

 Umpingave River, Natal {Lea); Natal [Brit. Mus.). 



