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A new species in the dendrochirotid holothurian genus Ocnus sensu lato is described from approximately 600 m depth in Taiaroa Canyon, off Otago, New Zealand. Ocnus sacculus new species has single rows of tubefeet only in the 3 ventral radii. Body‐wall ossicles consist of cups, knobbed 4‐holed buttons, and multi‐layered plates averaging 0.7 mm in diameter. Three brood pouches lie anteriorly on the inner surface of the body wall in 3 dorsal interradii; the mid‐dorsal pouch is largest. The pouches apparently have no permanent contact with the exterior; presumably birth takes place by rupture of the body wall.  相似文献   
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 An intercomparison of the thermal structure and the annual cycle in the tropical lower stratosphere of two reanalysis datasets is presented. These are from the National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) and the European Centre for Medium Range Weather Forecasts (ECMWF Re-Analysis: ERA). Generally, the ERA data are coldest and in better agreement with radiosonde observations; this is particularly apparent at 100 hPa where there is also a strong geographic bias, the maximum differences (more than 4 K) occurring over the southern Pacific and the Indian Ocean, with much smaller (sometimes reversed) differences over land. The NCEP temperatures are biased towards satellite-derived values, while the ERA data resolve the low tropopause temperatures much better. The lower ERA temperatures have important implications for the cross-tropopause exchange of water vapor. The meridional-height structure of the annual cycles agree quite well, but the amplitude in the ERA data is about 50% stronger than in NCEP at 70 hPa (in better agreement with previous studies) and weaker at lower pressures. As in previous studies, an anticorrelation is found between the tropical and extratropical temperatures of the reanalyses. The mean meridional flow at the equator is northward all year at all stratospheric levels in the NCEP data, implying a mass transport from the Southern to the Northern Hemisphere; in the ERA data the expected annual cycle (flow from summer to winter) is reproduced with very small annual mean exchange. Received: 17 June 1997/Accepted: 17 December 1997  相似文献   
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