Tanaidacea (Crustacea: Peracarida) of the North-east Atlantic: the genera Leptognathioides and Portaratrum of the ‘ Atlantic Margin’ Bird, Graham J. Journal of Natural History 2014 2014-04-23 48 29 - 30 1771 1815 [541,770,1368,1392] Malacostraca Leptognathioides Animalia Tanaidacea 15 1785 Arthropoda species undetermined    Remarks A few specimens previously identified by me as  L. politaappear in localities ‘out of place’ for this taxon and may represent  L. biarticulata. These samples are BIOFAR Stn 416 ( eleven specimens, IcelandBasin slope, 1038 m) and BIOICE Stn 2853 ( three specimens, IcelandBasin slope, 1840 m). The latter sample was the basis for the deepest record for  L. politain Bird (2001). Further study of these materials, currently at the Kaldbak Laboratory and IMNH respectively, would be required to validate the identifications, although the latter record is the more probable for  L. biarticulata.    Key to Leptognathioides species 1. Uropod exopod two-segmented (segment-2 small) ..................................... 2 - Uropod exopod one-segmented .................................................................. 3 2. Cheliped basis distal mass hardly longer than posterior lobe; pereopod-1 carpus superodistal margin with one bayonet spine and seta ........................  .......................................................................... Leptognathioides biarticulata  IcelandBasin - Cheliped basis distal mass clearly longer than posterior lobe; pereopod-1 carpus superodistal margin with three spines/setae………………………........ .............................................................................  Leptognathioidessp.KK#1 Kurile-Kamchatka Trench 3. Cheliped propodus inferior margin with obvious step, or process; incisive margin distal tooth very broad, about half length of margin; pereonites 2–4 [at least] as long as, or longer than, broad ................................................... 4 - Cheliped propodus inferior margin with at most a slight process; incisive margin distal tooth less than half length of margin; pereonites all shorter than broad .......................................................................................................... 5 4. Pereonites 2–4 only, as long as or longer than broad; pleotelson rounded ... .........................................................................................................  L. potens NE Atlantic - Pereonites 2–6 as long as or longer than broad; pleotelson with parallel-sided lateral margins ..................................................................................  L. rectus Weddell Sea 5. Cheliped fixed finger incisive margin with strong proximal triangular tooth; pleopod exopod with proximal seta ..................................................  L. polita N Atlantic - Cheliped fixed finger incisive margin with weak or no proximal triangular tooth; pleopod exopod without proximal seta .................................  L. vicina NW Atlantic