Opalinidae (Sarcomastigophora) in North American Amphibia. GenusOpalina Purkinje & Valentin, 1835

During 1992, the cloaca of 83 specimens of North American Amphibia from Algonquin Park and Kingston, Ontario, Canada, and from El Paso County, Texas, USA, comprising 14 species in seven families, were checked for opalinids. Opalina martinonae n. sp. was found in five of nine Rana sylvatica (Ranidae); O. obtrigonoidea Metcalf, 1923 in six of 11 Bufo americanus (Bufonidae) and two of nine Pseudacris crucifer (Hylidae); O. pickeringi Metcalf, 1923 in two of nine Pseudacris crucifer and in one of six Rana pipiens; and O. virguloidea Metcalf, 1923 in two of six Hyla versicolor (Hylidae). Opalina flava Stokes, 1884 is proposed for Cepedea flava (Stokes, 1884) Metcalf, 1923. The occurrence, evolution and biogeography of North American Opalina are discussed.     

耐受性定律的一个数学注记

在许多著作中关于耐受性定律的叙述大同小异。为了视限制因子原理和Liebig 最小因子定律为耐受性定律的特殊情况(某些侧面),我们采用[1]对耐受性定律的叙述:一种环境因子对每一种生物都有一个范     

关于Taylor幂法则的统计学讨论

自Greenwood于1920年把负二项分布引做昆虫种群空间格局模型以来,昆虫种群空间格局分析的理论和方法大致经历了两个阶段的发展:五、六十年代以前,是以少数离散型概率分布为主要模型;其后,各种聚集性指标和一些回归公式被提出,显示了比原有     

Opalinidae (Slopalinida) in South American Amphibia. GenusOpalina Purkinje & Valentin, 1835 in Colombia

In September and October, 1992, 97 Colombian amphibians at eight sites and comprising 25 species in eight families were checked for opalinids in the cloaca.Opalina elongata Carini, 1937 was found in one juvenile ofCentrolenella sp. (Centrolenidae) andO. phyllomedusae Metcalf, 1923 (status amend.) in one of twoPhyllomedusa hipocondrialis (Hylidae) both from Villavicencio (Meta). Metcalf's Neotropical species ofOpalina are reviewed.