Comparison Between the N.Z. and Tasmanian Males

The Tasmanian male is drawn on Pl. 41, fig. 11, and parts of the N.Z. male are given on Pl. 41, fig. 11B and Pl. 41, Figs. 12A and 12B and 13B. Having regard to the state of the material, three parts for comparison were chosen: (1) The lengths of the 3rd and 4th segments of the antenna. (2) The shape of the haltere. (3) The lengths and shape of the coxa and femur of the hind leg.

In the first place the N.Z. male is a more heavily built insect (Text-fig. 2) and deeply pigmented. Dr. Evans' specimen of the Tasmanian male had been twentythree years in alcohol, had probably bleached somewhat but was throughout more yellowish than the N.Z. form. It is well to remark that in such cases colour is not always of certain value: for the N.Z. male was found near enough the opening of the cave to get some daylight, whereas the Tasmanian specimen was found in a darker place. In Pl. 41, fig. 11A, are five segments of the antenna of the Tasmanian male, and in Pl. 41, fig. 12A, four segments of the N.Z. male. Reference to segments 3 and 4 in each will show that the N.Z. male has thicker, heavier, shorter segments, the Tasmanian form longer and slenderer parts.

In Pl. 41, fig. 12D, are camera lucida drawings of the lengths of the antennae of first, the Tasmanian male, and below the N.Z. male and female Both of the latter specimens were presumably from full grown larvae, and were captured in the Waitomo caves. There are sixteen segments in the antennae of all these specimens In fig. 12D, the natural contour of the antennae has been drawn. In Figs. 13A and B, are firstly the haltere of the Tasmanian male (A), and (B), that of either sex in the N.Z. form: here again the N.Z. form is the thicker and less graceful In fig. 11B of Pl. 41, the coxa and femur of the metathoracic leg are given for comparison with the same region in fig. 11 of the Tasmanian form.

Ferguson does not state where he saw a N.Z. male. There is still doubt as to whether only one species of Bolitophila exists in N.Z., and the matter of comparisons between the N.Z. and the Tasmanian forms is not by any means settled. It is curious that Ferguson did not stress the fact of the remarkably delicate build of the Tasmanian male.