316 ox TSETSE-FLIES FROM AFRICA. [NoV. 17, 



Christmas- Island Dove {Chalcopha'ps natalis), from Christmas 

 Island, in the Indian Ocean, presented by Capt. A. W. Cole, Oct. 27th. 



Mr. Henry Scherren, F.Z.S., exhibited the front horn of a 

 Burchell's Khinoceros {Rhinoceros siinus), the largest yet received 

 in England from the Soudan. It was the property of Col. B. 

 T. Mahon, C.B., D.S.O. (for whom it had been mounted by 

 Mr. Rowland Ward), and measured along the anterior curve 

 36| in., with a circumference at the base of 19| in. This is only 

 three-fifths of the length of the record horn obtained in South 

 Africa by Roualeyn Gordon Cumming, which has a length of 

 62;^ in. In addition to the horn exhibited and that belonging to 

 Capt. Hawker (c/. above, p. 194), other horns from the same 

 region were in the possession of Major-Gen. Sir F. R. Wingate, 

 Hon. Capt. MclSTaughten, Major Sanders, and Capt. J. G. A. 

 Massey. Mr. Scherren stated that this Rhinoceros was reported 

 as being fairly numerous on the northern boundary of the Congo 

 Free State and in the adjacent parts of the Soudan, and that 

 Mr. Rowland Ward had knoMm of these horns coming from that 

 district for many years before Major Gibbons secured his specimen 

 {cf. P. Z. S. 1900, p. 949). 



Mr. R. I. Pocock, F.Z.S., exhibited a piece of basalt picked up 

 between tide-marks on the coast of Victoria, Australia, by 

 Mrs. Kenyon, which contained a specimen of lihe web of the 

 Marine Spider Desis kenyonce, described in the ' Proceedings ' of 

 last year \cf. 1902, ii. p. 102). Although broken, the web served 

 to illustrate the habit of these marine spiders of spinning a 

 closely-woven sheet of silk over a crevice in the rock as a pro- 

 tection against the rising tide. 



Mr. Pocock also gave an exposition, illusti'ated by drawings, of 

 a new suggestion as to the white rump-patches of Ungulata, witli 

 special reference to the races of Burchell's Zebra. 



Mr. E. E. Austen exhibited specimens, Avith pupae, of Glossina 

 palpalis Rob.-Desv., the species of Tsetse-fly which is the active 

 agent in the transmission of sleeping-sickness in Uganda, by 

 conveying Tryioanoso'ma castellanii Kruse, the parasite which is 

 the cause of the disease, from man to man. Examples of four 

 other species of Tsetse-flies were also shoAvn for the sake of com- 

 parison, and the general characteristics of the genus Glossina, 

 which is confined to Africa, were pointed out. Attention was 

 drawn to the remarkable mode of reproduction in the genus, 

 which renders it impossible to attack the insects in their breedings 

 places, as has been successfully accomplished in many places in the 

 case of mosquitos ; for, instead of laying eggs, Tsetse-flies produce 

 but a- single larva at a birth, which forthAvith craAvls aAvay and 

 assume? the pupal conrlition on reaching some sheltered spot. SeA'en 

 species of Tsetse-flies are at present knoAvn, and of these at least 

 two, Glossina morsitans WestAV. and Gl. pallidipes Austen, are 

 probably concerned in the dissemination of '• IS^agana." or Tsetse- 



