Page:The Zoologist, 4th series, vol 1 (1897).djvu/550

518 an area, say eight square miles; but I am not sufficiently acquainted with them to know whether this is an unusually large number.

Perhaps the few succeeding notes, such as they are, may be of use and interest to you. I reached this locality in the end of July, when there were apparently no Cicadas about. The little blackish species, Tibicen nigricans, Stål, was the first to appear, which it did during the second week in August, remaining till the end of September. Its call is quite distinct from all the other species, and not nearly so loud. It consists merely of a short chirp, hanging slightly on one note, and ending with a quick rise, the sound being incessantly repeated. The next species, Platypleura rutherfordi, Dist., began calling in the middle of September. I made no particular note of its cry, except that it was much louder than that of the former, and continuous. It was apparently confined to the smoother trunks of the "mosasa" tree. It continued calling until Oct. 15th, when I shifted camp four miles away. At this spot it did not occur, owing, I presume, to the fact that the "mosasa" tree is not found there, being replaced by a very nearly allied species, called by the Kafirs "mfuti." However, when I went back on the 22nd I could not find any of them. At my new camp, on Oct. 17th, I caught three species.

The species, Pœcilopsaltria marshalli, Dist., occurs only on "mopani" trees, frequenting the smaller branches, to which its colouring is very well adapted. Indeed, I have found it to be one of the most difficult to detect, which doubtless accounts for the fact that it is the most easily approached, and sits very close. Indeed, I have often struck the branch on which one has been sitting, sharply with my net, without disturbing it. Its cry is the most monotonous of any species I know, being one continuous unbroken churr. I noticed a Cicada calling among "mopanis" in the end of September, which was probably this species. It disappeared in the middle of this month.

Pœcilopsaltria bombifrons, Karsch, is not confined to any one tree, but frequents the small, smooth branches of many trees and shrubs. Its cry has a considerable range, starting on a somewhat low note and gradually rising to a high pitch, then falling again, and so on. I once came across a very large concourse of this species, there being quite sixty on a small bush, and making a terrible noise. At the first sweep I took two males and five females, and of the twenty I caught only six were males. By the way, I have noticed several facts which would lead me to suppose that Cicadas were polygamous, and I should be much interested to know whether your experience would bear this out.