12 ME. G. A. K. MARSHALL ON COLEOPTERA [Jail. 19, 



The most stiiking point in connection with these figvu-es is 

 the mai'kecl isolation of the south- westei-n insect fauna as com- 

 pared with that of the rest of the sub-continent. Of the 93 species 

 of Ilijjporrhintis occurring in the Oape Colony, only three are at 

 present known to exceed its limits. Of these one is the most 

 wide-i-anging S. African species, furims. The others are quadri- 

 nodis, of which I have seen only a single example from Natal ; 

 and binodis, a littoral species which extends from Algoa Bay along 

 the Natal coast and up to Delagoa Bay. The insect fauna, of the 

 Orange River Colony is at present so little known, that the figures 

 in the above-given table can give no true idea of the occurrence 

 of Ilipporrhinus in tha,t region ; but it seems probable that the 

 genus has extended from its original headquartei's in the south- 

 west through that Colony into the Transvaal, rather than thi'ough 

 the forest-regions of the Transkei, Pondoland, and Natal. It must 

 be noted, however, that nothing whatever is known at present. of 

 the Cui'culionidfe of Basutoland or Griqualand East. 



This pi-esumed migration of the genus is supported by the 

 gradual diminution of the species northwards, and also by the 

 fact that tlie only two which occvir to the north of the Zambesi, 

 viz. tennegranosus and myasce, are clearly only modified forms 

 of common South African species, viz. furvus and «s/jer respec- 

 tively. The j)rogenitors of the two former species probably 

 extended their raiige at a time when the mountainous backbone 

 of Eastern Africa, was more continuous than it is today, for within 

 the tropics the genus does not appear to exist below the 3000 ft. 

 level. From Natal and the Transvaal the northward movement 

 has probably taken place along the eastern face of the inland 

 plateau, for the insects of Umtali (3700 ft.) show many affinities 

 with the fauna of those Colonies which are not observable at 

 Salisbury, only 175 miles north-west of it. At present only five 

 species of Ilipj^orrhinus have been found at Umtali ; of these 

 only two occur also at Salisbury, whereas no less than four out of 

 the five are Transvaal species. So fai- as the coastal belt is con- 

 cerned, Delagoa Bay is the most north ei'ly point from which the 

 genus has been recorded, and it is doubtful whether it extends 

 very much furthei' ; foi- it is certainly absent from Beira, 3;^° 

 within the tropic, where Mi'. P. A. Sheppard has been carefully 

 collecting Coleoptera for some years past. 



The southern origin of Hipporrhinns further receives interesting 

 confirmation from the fact that some of its nearest allies are to 

 be found in Australia. Indeed in the case of certain species of 

 the genus Leptops, so close is the genei-al resemblance to Hip>2)or- 

 rhinus that they are frequently included in the latter genus in 

 collections. However, the neai-ly allied South African Soniatotides 

 show an even closer structural affinity with the Amycteiides of 

 Austi'alia. The existence, in past geological epochs, of some 

 land connection between South Africa and Australia is rendei'ed 

 highly piobable by the occurrence of similai- affinities in widely dif- 

 ferent orders of animals and plants, wliich cannot be satisfactorily 



