Limea lirata, Allen, 2010
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publication ID |
https://doi.org/ 10.1080/00222930310001647442 |
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persistent identifier |
https://treatment.plazi.org/id/7A20464E-EC0D-FFFF-FD9C-6825FCC7C8EA |
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treatment provided by |
Felipe |
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scientific name |
Limea lirata |
| status |
sp. nov. |
Limea lirata View in CoL n. sp.
( figures 36 View FIG , 37 View FIG , 46c View FIG )
Type locality. North America Basin, Atlantis II sta. 119, 32 ‡ 15.8 ’ N,
64 ‡ 31.6 ’ W, 2095 m.
Holotype. BMNH.
Material examined. Atlantis II sta. 119, 32 ‡ 15.8 ’ N, 64 ‡ 31.6 ’ W, 2095 m, 171 spec.
Distribution. Found only at one station on the lower slope of the North America Basin.
Description ( figures 36a, b View FIG , 46c View FIG ). Shell very small (max. recorded height 2 mm), height to length ratio 1:0.79, extremely fragile, moderately inflated, equivalve, ovate, somewhat inequilateral, oblique, approximately 18 ‡ to vertical, very pale fawncoloured periostracum, transluscent, ornamented with many extremely fine concentric striae, fine particles attach to shell surface and which give rise to colour, single, fine internal axial ridge and groove in both valves not reflected on outer surface and more pronouced in some specimens than others, ears not pronounced, no subauricular sinuses, postero-dorsal margin rounded at hinge margin, antero-dorsal margin makes angle with hinge margin, ventral shell margin broadly curved; umbos moderately prominent; hinge margin straight, hinge plate extremely narrow, with few barely discernible irregularly spaced teeth teeth particularly on the posterior plate; ligament small, elongate oval, resilifer protrudes ventral to umbo. Prodissoconch I length~123 M m; interdissoconch indistingishable.
Anatomy ( figure 37a, b View FIG ). Mantle margin relatively broad, each middle sensory fold bears one small anal tentacle and four relatively elongate annulated tentacles, evenly spaced comprising an antero-lateral, a postero-lateral and an anterior and a posterior ventro-lateral, additionally three or four antero-lateral papillae dorsal to antero-lateral tentacle; gill consists of an inner demibranch comprising 15–16 homorhabdic filaments, most anterior reflected to form a short ascending lamella. In other respects the anatomy is similar to that of other species described here.
Remarks. The species is named after the distinctive lirate sculpture of the shell. This is the smallest species in the collections. It is reminiscent of Limea clandestina described by Salas (1994) and Hoeksema and Janse (2002) from the West European Basin. This latter species is also extremely small (ca 1 mm) and regarded as neotenous by Salas (1994), however, it differs from L. lirata by having a much more slender and very much longer toothed, hinge plate. Larger specimens of L. clandestina unlike L. lirata bear marginal ribs and are not so oblique.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.