. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. Deronectes depressus, Fab., and elegans, Panzer. 297 characters, taken in conjunction with the thorax-characters, generally enable one to separate the males with comparative ease, and so far, with one exception, I have always been able to determine the species on these characters, a subse- quent examination of the sedeagus confirming my previous determination. 3. The jEdeagus.—In the northern species this organ, viewed from above, has a broad apex, while in the common form it
. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. Deronectes depressus, Fab., and elegans, Panzer. 297 characters, taken in conjunction with the thorax-characters, generally enable one to separate the males with comparative ease, and so far, with one exception, I have always been able to determine the species on these characters, a subse- quent examination of the sedeagus confirming my previous determination. 3. The jEdeagus.—In the northern species this organ, viewed from above, has a broad apex, while in the common form it has a pointed one, and until my recent visit to Gallo- way I regarded this character as definitely proving that we have two distinct species. On looking through my additional material from eighteen more lochs, I had no difficulty in separating the males of the two forms on the thoracic and. Apices of sedeagi of specimens of D. depressus (" the northern species ") and D. elegans ("the common species "), chosen to show the range of variation.—Figs. 1-9. I), depressus (1, Talkin Tarn ; 2, L. of the Lowes ; 3, L. Urr ; 4, L. Doon ; 5-9, L. Dungeon). Figs. 10-18. D. elegans (10, 11, R. Spey; 12, 13, Long L. of the Dungeon; 14, L. Stroan ?; 15, L. Aber; 16, ; 17, Broadford River, Skye; 18, Moorlinch, N. Somerset). tarsal claw-characters except in one case—Loch Dnngeon* the specimens from which I put down as " ; On examining the sedeagus of these specimens I found a range of width in the apex from that of typical " northern " specimens to a comparatively narrow and bluntly pointed form (vide figs. 5-9 infra). Now I had previously noticed that there was a variation in. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original London, Taylor and Francis, Ltd
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