OCR Text |
Show 1891.] ON BUTTERFLIES FROM SOUTH-WESTERN AFRICA. 59 Figs. 4 & 5. Lateral and dorsal views respectively of left valve of small adult Unio, showing the notches, x, produced on each line of growth by the previous constriction caused by the shell-teeth of the Glochidium-shell. Fig. 6. Diagram to show the direction of ciliary currents on external surface of nephridium. 7. Diagram to show valvular action of ventral edge of mantle-flaps. a, a', right and left valves of shell; b, b', right and left mantle-folds; c, c', thickened margins of b, b'; d, d', lines of attachment of b, b' to a, a'. The arrows indicate the direction of water-pressure. 8. Diagram of relation of gill-lamella? to show how the ova are prevented from falling into the internal gill, a, visceral mass ; c, mantle-flap ; d, axis of gill; e, inner, er, outer lamella of external gill-plate; f, outer, fr, inner lamella of internal gill-plate; g, line of concrescence ; i, suprabranchial space of subpallial chamber. 3. On Butterflies collected in Tropical South-western Africa by Mr. A. W . Eriksson. By ROLAND TRIMEN, F.R.S., &c.j Curator of the South-African Museum, Cape Town. [Eeceived December 8,1890.] (Plates VIII. & IX.) "Well known for his many years' experience as explorer and hunter in the tropical Interior, and for the zeal and success with which he has collected and observed the ornithological fauna, Mr. Axel W . Eriksson has latterly, at m y instance, turned his attention to the insects inhabiting the less known tracts. The collection of which the Butterflies now under notice formed the larger part was made by him during six months-1st August, 1887, to 25th January, 1888-spent in travelling between Ehanda, in the Southern Ombuela (or Ambuella) country, and Omborombongo, in Central Damara-land. The country traversed may be said in general terms to be bounded, except to the South-west, by the rivers Cunene, Okavango, and Omaramba-Oamatako, and it extends from North to South over about five and a half degrees of latitude (15° 15' to 20° 45' S.), and from West to East almost the same of longitude (15° to 21° 20' E.). The route pursued and the time spent in each locality appear from Mr. Eriksson's notes to have been as follows, viz.:-Omrora, " between Ovaquenyama and Ombuela," 1st to 25th August; Ehanda, 26th August to* 30th September ; Humbe, Cunene River, October ; Omrora again, November; Otiembora, 20th November to 3rd December ; the course of the Okavango River, "between the tributaries Omaramba-Caronga and Omaramba-Oamatako," December; the course of the Omaramba-Oamatako, " between its junction with the Okavango and Otjitoe/' 2nd to 14th January, 1888 ; and the course of the same river, "between Otjitoe and Omborombongo," 15th to 25th January. This route is remote from the sea-coast, never |