The annals and magazine of natural history : zoology, botany, and geology . ereas theouter (posterior) claw in the northern species is often slightly shorter than the inner (anterior) one, in the common speciesthe two claws are more usually equal in length. The claw- Deioncctea ilepressus, Fal>.^ and clele one to si-parato the mah»3 with comparativeease, and so Far, with one exception, I have always beenahle to tletcrinine the specios on these characters, a subse-quent cxaniiinitiou of the jodeagus confirming my previousiletermination. 3. The yKJeaove, has a broad apex, wiiile in the common
The annals and magazine of natural history : zoology, botany, and geology . ereas theouter (posterior) claw in the northern species is often slightly shorter than the inner (anterior) one, in the common speciesthe two claws are more usually equal in length. The claw- Deioncctea ilepressus, Fal>.^ and clele one to si-parato the mah»3 with comparativeease, and so Far, with one exception, I have always beenahle to tletcrinine the specios on these characters, a subse-quent cxaniiinitiou of the jodeagus confirming my previousiletermination. 3. The yKJeaove, has a broad apex, wiiile in the commonform it has a pointed one, and until my recent visit to Gallo-way I re;farded this character as definitely proving that welinve two distinct species. On looking throu<^h my additionalmaterial from eighteen more lochs, I had no difficulty inseparating the males of the two forms on tiie thoracic and. Apices of ledeajri of specimens of IJ. dfjn-essus ( the northern species )and U. vleyaus (* the coniuion sjiecies ), chosen to show the rangeof variation.—Figs. 1-9. 1). dv]>rctim« (1, Talliin Tarn ; 2, L. of theLowes; 3, L. Urr; 4, L. Uoon ; fj-O, L. Dun^eon). Figs. ), eltffrtnt (10, 11, li. Spey ; 12, 1.^, Long L. of the Dun>jreon ;14, L. Stroan : 16, L. Aber; 10, L. Skene ; 17, Broadford liiver,Skye; 18, Moorlinch, N. Soujerset). tarsal claw-characters except in one case—Loch Dnngeon>the specimens from ?which I put down as tmcertain. Onexamining the redengus of these specimens I found a range ofwidth in the apex from that of typical northern specimensto a comparatively narrow and bluntly pointed form {videfigs, ^-i) infra). Now I had previously noticed that there was a variation in 298 Caph F. BalCour-Browne on ?width in botli species, but until I examined the LocliDunjioon specimens there was always a wide gap betweenthe two types of aideagus, the northern
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Keywords: ., bookcentury1800, bookidser9annalsmaga, booksubjectnaturalhistory
