摘要:

AbstractProschizorhynchus nahantensissp. n. andProschizorhynchus papillatussp. n. are described and their taxonomy discussed.P. nahantensisis characterized by its penis papilla which has a proximal spherical and distal tubular portion. A simple stylet is present. The female system is distinguished by the external opening of the vagina and the prominent bursal mouthpiece.P. papillatusis distinguished by the two muscle layers of the copulatory organ, the large straight stylet in the penis papilla, a single gonopore and uterus. Notes on the ecology of the species are included. Views are given on the taxonomy of the genusProschizorhynchusMeixner, 1928.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1974.tb00808.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractA qualitative and quantitative study of eugregarine parasites in different dragonfly species was performed around a breeding site at Bergen (Western Norway). Dragonfly larvae were never found to harbour gregarines. As a general rule, the number of dragonflies infected and the number of gregarines present in each individual host increased during the flying season. In the zygopteransCoenagrion hastulatum(Charp.),Enallagma cyathi‐gerum(Charp.), andPyrrhosoma nymphula(Sulz.), the majority became heavily infected. Discoloured, feeble specimens captured in the field exhibited extensive damage to the midgut, probably progressing to bacterial septicaemia. The histopathology of the midgut wall has been recorded from scarcely visible alterations to massive disruption of the epithelium. In these species, gregarine infection apparently reduced the longevity of adults. The population ofLestes sponsa(Hansem.) was moderately infected and injuries of the midgut seldom occurred. In the only infected anisopteran,Sympetrum danae(Sulz.), gregarines seemed unimportant and caused no damage to their hosts. Each gregarine species seemed to thrive in several dragonfly hosts, and a host could harbour at least two different gregarine species at the same time. The pattern of infection is discussed against the background of climatic and edaphic condition

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1974.tb00809.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe present paper contains a revision of the Arctic‐Atlantic Rissoidae (Gastropoda, Prosobranchia). Twenty‐two species are recognized. Two new species,Alvania obliquaandAlvania pseudoareolataare described, both previously wrongly identified. One new genus,Frigidoalcania, is established withRissoa janmayenias type‐sp

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1974.tb00810.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe skeletal marks present in numerous po'ikilo‐therm Vertebrates are, for numerous workers, the expression of an annual growth periodicity. They have been used, therefore, to calculate the individual age. Nevertheless, few works exist about the nature of these marks. We have begun, by various techniques to study the histo‐logical structure of these marks on a series of nativeVipera aspis(L.). Skeletal marks are made of two types of osseous tissues: (1) lamellar bone, with parallel fibers, for theannuli, considered to be the result of a period of slow growth; (2) woven fibered bone, for the zones, considered to be the expression of a period of rapid growth. The value of these skeletal marks as an index of age is still to be demonstrated by experimental methods.RésumeéLes marques squelettiques présentes chez de nombreux Vertébrés poikilothemes, témoignent pour les auteurs d'une périodicité annuelle de la croissance. Elks ont de ce fait été utilisées dans le calcul de 1'âge individuel. Cependant peu de travaux nous renseignent sur la nature de ces formations. Nous avons entrepris sur un lot de Vipera aspis (L.) indigènes et par des techniques variées, l'étude de la structure histologique de ces stries de croissance. Celles‐ci correspondent A deux types de tissus osseux: (1) os lamellaire ou L fibres paralleles, pour les annuli, considéré comme le resultat d'une phase de croissance ralentie; (2) os A fibres entrecroisées, pour les zones, consider6 comme le resultat d'une phase de croissance rapide. La valeur des marques squelettiques comme critère d'Lge reste cependant A démontrer par

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1974.tb00811.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY