OCR Text |
Show 464 MR. H. R. HOGG ON AUSTRALASIAN SPIDERS. [Dec. 2, Genus E odelena, nov. This genus I have formed for two specimens, one a fully developed male, the other not adult, sent to the British Museum by Prof. Baldwin Spencer, of Melbourne, in 1888. They were collected on King's Island, Bass's Straits, and, but for their smaller size, in general appearance are scarcely distinguishable from Delena cancericles Walck. On looking at the male palp, however, it is seen that what should be a flagellum of ten spirals makes less than one whole turn round the end of the conductor, which is merely flattened and curls round far enough to be the shape of a hook. As the palp does not develop by degrees, but comes out fully formed after casting the skin at the last moult, this must either be a reversion to an ancient form or a remanet. The fact that the palpal development is so similar through different genera indicates that it is an older development than that of the form of cephalothorax &c.; and as the flattened forms must almost of a certainty succeed the unflattened, it is more likely to be a reversion to the original type than to have remained on without alteration. However, if such were thought likely, the hills (now islands in Bass's Straits) would be a not unlikely place for the ancestors to remain. It is in any case an interesting instance of the reproduction of a missing link, and indicates the line along which the specialization has taken place. Type, Eodelena spenceri. E odelena spenceri, nov. sp. (Text-fig. 104.) This species differs in nowise in coloration and shape from Delena cancerides, but has the important difference detailed above, and the tibial apophysis of male palp is single instead of double. In the front row of eyes the laterals are nearer to the medians than in that species, being once and a half the distance between the latter. Measurements in millimetres. Male. Long. Broad. Cephalothorax .> • • 6 * 6 * Abdomen ......... 6| 5I Mandibles......... 3 Pat. & Metat. Coxae. Tr. & fem. tib. & tars. Legs ................. 1. 24 8 1 0 1 2. 2 1 0 13 12 3. 2 7 7 7 4. 0^14 8 8 8 Palpi ................. 1 2| H 2 30| = 37j 23 = 26| |