Gyrosigma peisonis var. major var. nov., a new variety of Gyrosigma peisonis (Bacillariophyta) from Lake Qinghai, China

The morphology and ultrastructure of Gyrosigma peisonis var. major var. nov., a new variety of Gyrosigma peisonis found in Lake Qinghai (China), are described here on the basis of light and scanning electron microscopy. Most of the morphological features of this new variety are identical to those of the nominal variety Gyrosigma peisonis var. peisonis, but the variety major differs in its distinctly larger cell size and its higher value for the longitudinal/transverse stria density ratio, however. The seasonal variation of this taxon, which was investigated by a sediment-trap study is also discussed.

Electron Microscopy of Globular Hyaline Micro-Thrombi

Globular hyaline micro-thrombi(GHM) are round or oval, eosinophilic, strongly PAS-positive intravascular coagulation products with a diameter between 3 and 60/u. Immunhistochemical investigations give strong evidence that they are composed of highly polymerized fibrinogen derivatives. The ultrastructure of these GHM is characterized by spherical space lattices of frequently interconnected bundles of fibres with a periodic transverse stria-tion and the fibrin-characteristic axial periodicity of 23 nm. The densely packed spherical space lattices are surrounded by a so-called corona, plump or slender bundles of fibrin fibres characterized by the same uniforme periodic axial striation of 23 nm that spread radially over the surface of the micro-thrombi. GHM apparently originate from the interlocking and internetting of intravascularly preformed, partly polymerized, filamentary intermediates of fibrinogen-fibrin conversion in the flowing blood. Part of these GHM, on the other hand, lack this axial periodicity and the fibrillary structure of the spherical space lattices is replaced by nearly amorphous finegrained precipitates. The disappearance of the axial periodicity and of the fibrillary structure of the spherical space lattices is considered to be the morphological equivalent of a secondary fibrinolysis in the centre of the GHM. The morphogenesis of GHM in states of hyperdynamic shock is discussed.

New injurious Curculionidae (Col.)

Aedophronus echinatus, sp. n. (Pl. xxi, fig. 2).Derm black, with dense brown scaling, usually with an indefinite mottling of darker and paler scales ; the inflexed margins of the elytra fuscous.Head not very convex, with the median stria extending to the vertex and the anterior transverse stria slightly curved ; the infra-ocular margin much narrower than the base of the scape and not projecting ; the setae short, stout and curved backwards ; the eyes comparatively large, highest much behind the middle, and with the hind margin devoid of scaling. Rostrum longer than the head (5·5 : 4), much shorter than its basal width (5·5 : 7·5), narrowed in front, straight at the sides, with a shallow impression on the apical half and with no median carina ; the marginal carina of the epistome obtuse but distinct. Prothorax transverse (3·5 : 6), strongly rounded at the sides, widest at the middle, subtruncate at the apex, which is only slightly narrower than the base ; the dorsum with an abbreviated median stria on the basal half and bearing on the disk short curved setae like those on the head, the lateral ones much longer, stout, straight and pointed (when unbroken), the longest being about as long as the scape.