A PRELIMINARY TAXONOMIC REVISION OF THE BRITISH WHITEFISH WITH ESPECIAL REFERENCE TO THE GWYNIAD OF LLYN TEGID (BALA)

The paper deals with a biometrical analysis of forty-one specimens of the Gwyniad, Coregonus clupeoides pennantii (Cuv. et Val.) of Bala Lake, (Llyn Tegid) North Wales. Tho Gwyniad shows the greatest relationship to the continental coregonids Coregonus lavaretus . It is proposed that the taxonomy of the British whitefishes be revised and that the Gwyniad be classified as Coregonus lavaretus pennantii (Cuv. et Val.). Similarly, it is proposed that the Powan of Loch Lomond be classified as Coregonus lavaretus clupeoides Lacépède. The classification of the Schelly from the English Lake District needs further investigation.     

A NEW MACROPETALICHTHYID FROM CHINA, WITH SPECIAL REFERENCE TO THE HISTORICAL ZOOGEOGRAPHY OF THE MACROPETALICHTHYIDAE (PLACODERMI)

SudsrucodedMChy,1848OrderthytdaJaekd,1911wMarmpeytdaeEastman,l898beusHmpopsges'nov'Tpe~Hofrpetahchdnytonguaeasisgen'etSP'nov'~dsSmall-edmacropetalichthytd'Roedandpincalplatheincontac,completeymparahngthepreorbitalplaus'Posteriorpit-linesextendingposteri0riytothetal-line,and0SSficahoncenterofthenuchalplatesitUatalattheposteriorhalfoftheplate'Supia0rbitalsensorycanalnotconvergingwiththeposteri0rpit-lines'~gyHOl-(Gr')whole,enhre,COmPlete;-Petahchthy(G'),ofAnuedinthe.genencnamesofthePeta…     

棉红蜘蛛(Tetranychus bimaculatus Harvey)研究初步报告:(一)寄主植物与预防蛛害的关系

一、引言 棉红蜘蛛(Tetranychus bimaculatus Harvey)是我国棉花主要害虫之一,它的分布很广,被害棉株轻的叶片变色,重的则落叶落铃,影响棉花产量很严重。早在1923年史振东即有报导。但是这样厉害的大害虫,在反动政府时代除了吴振钟、傅