Volume 79, Issue 4
April 1974, pages 147-172
pp 147-153 April 1974
The nocturnal periodicity of six species of black flies (Diptera : Simuliidae) of Darjeeling was found out from the data of light trapping made in three equal shifts for each of the five nights selected in 1969. The incidence of these flies was marked by hourly variation. Each ofpraelargum, gracilis, himalayense, grisescens andtenuistylum showed its peak abundance in the middle of night, whilerufibasis was at its peak at the end of night. The percentage composition ofgracilis andgrisescens in the last shift was higher than that in the first shift, and this was the general trend of the species of these flies taken together. The incidence ofpraelargum andtenuistylum in the first shift was higher than that in the last shift. Inhimalayense the distribution was similar in any of the two shifts, while inrufibasis it was found to rise gradually, thereby attaining itself to its peak at the end of night. The incidence shown by the two sexes of a species did not always obey the general trend and this is discussed in detail in this communication.
pp 154-159 April 1974
Acanthospermum hispidum DC. exhibits several anatomical characters commonly met with in the family Asteraceae,e.g., (i) variety of trichomes, (ii) a ring of discrete vascular bundles, heterogenecus pericycle and resin ducts in the stem, and (iii) anomocytic stomata and absence of hypoderm in the leaf. These with some others can serve as a diagnostic combination of characters for the species. Among the latter, mention may be made of (i) absence of root-pith, (ii) trichome complement made up of glandular and non-glandular uniseriate hairs, (iii) resin ducts present in root, stem and leaf, (iv) collenchymatous stem hypodermis interrupted by chlorenchyma below the stomata, (v) trilacunar node, (vi) foliar supply disposed as a crescentic arc of three discrete vascular bundles, (vii) dorsiventral mesophyll, (viii) absence of hypoderm in the leaf, and (ix) superficial origin of cork cambium in root and stem.
pp 160-172 April 1974
Four novelties belonging to the genusFimbristylis which came to light during the revision are described here. They belong to the sectionsDichelostylis, Pogonostylis, Trichelostylis andHeleocharoides respectively.