On Freshwater Fossils from Central South, Africa. 241 



From an examination of the few specimens in the collec- 

 tions I have had access to, Schiner's remarks appear correct, 

 but the drawing of the genitalia of D. cupreus by Loew is 

 probably not very correct — it does not represent the genitalia 

 of D. chalcogaster accurately. 



Walker's D. phoeax appears to be identical with tliis 

 species, but the type is in very bad condition, from S. Africa 

 {Dr. Smith), 44,6. 



Dysmachus chalcogaster, Wied. 



Zool. Mag. i. pp. 3, 35, 50 [Asilus] (1819) ; id. Dipt. Exot. p. 189, 13 

 [Asilus^ (1821) ; id. Ausszweifl. Ins. i. p. 442, 26 [.4«7m«] ; Schiner, 

 Verb, zool.-bot. Ges. Wien, xvi. p. 684, 26 [Lophonottis] ; id. xvii. 

 p. 401. 101 [Lophonottis] (1867). 



Dysmachtis cupreus, Loew, Dipt. Siidafrik. i. p. 154, 2, pi. ii. fig. 5 

 (1860). 



There do not appear to be any specimens of this species 

 in the Brit. Mus. Coll., but in the Cape Mus. Coll. are a 

 male and two females from Cape Colony answering to the 

 description as given by Wiedemann and Schiner. It has a 

 golden-yellow moustache, with black bristles at the sides 

 and above. Schiner gives the genitalia a» long and club- 

 shaped, the forceps bifid. The above specimens measure 

 23-27 mm. ; Wiedemann gives 16 ram. 



[To be continued.] 



XXXI. — On some Freshwater Fosails from Central South 

 Africa. By R. Bullen 2sewton, F.G.S. 



(Published by permission of the Trustees of the British Museum.) 



[Plate VIII.] 



Introduction. 



This communication deals with an enquiry into the history 

 of certain obscure freshwater fossils occurring in a iiii^hly 

 siliceous rock from Africa, the important outcome of which 

 is in respect of their geological age. In this coiniexioii, 

 therefore, I have had referred to me lor determination three 

 hand-specimens of a chalcedonized rock containing fossils, 

 which have been discovered by Mr. A. J. C. Molyneux, 

 F.G.S., in the Matabeleland region of Central South Africa. 

 Ann. (j& Mag. N. Hist. Ser. 9. Vol. v. 17 



