Search results for "Pygidium"
showing 5 items of 5 documents
Pseudomastus deltaicus , gen. et sp.n. (Polychaeta: Capitellidae) from a shallow- water bay in the North- Western Mediterranean Sea
1992
4 Páginas ; 2 Figuras
The exocrine glands of Dysdercus cingulatus (Heteroptera, Pyrrhocoridae): Morphology and function of nymphal glands.
2018
The exocrine glandular system of the nymphs and the adults of Dysdercus cingulatus were studied. The D. cingulatus nymphs present 3 dorso-abdominal glands (lying under the 3rd, 4th, and 5th abdominal terga) and a pair of dorso-lateral pygidial glands on the pygidium (tergum 8). Histological and ultrastructural studies show that the upper and lower walls of the dorso-abdominal glands differ in structure; 3 types of cells were described: epidermal cells, unicellular secretory cells, and multicellular secretory units. Each of these exocrine glands plays an important part in the behavior of the nymphs (gregariousness, alarm, defense). The morphology of the various glands is discussed, and the c…
Pheromones inBlattella germanica andBlaberus craniifer (Blaberoidea): Glandular source, morphology and analyses of pheromonally released behaviours
1993
Females ofBlattella germanica andBlaberus craniifer produce a volatile sex pheromone attractive at a distance for conspecific males. During the emission of the pheromone, females ofB. craniifer adopt a typical calling posture; we never observe such a stance inB. germanica females. For both species, the glandular structures responsible for pheromonal production are located on the female pygidium. InB. germanica, the thickness of the glandular epithelium is clearly correlated with the attractiveness of females, being maximum for 13 day old females. The functions of the pygidial glands are discussed in both species.
ParadoxidesbrachyrhachisLinnarsson, 1883 versusParadoxidesmediterraneusPompeckj, 1901: a problematic determination
2010
A revision of paradoxidid trilobites reveals that previous identifications of specimens from Sardinia and Spain as the Nordic trilobite species Paradoxides brachyrhachis Linnarsson, 1883, are mistaken. The southern species, occurring also in France, is here referred to Eccaparadoxides mediterraneus (Pompeckj, 1901). Main differences are seen in the preocular field, pleural furrow and pygidium. The species P. brachyrhachis is referred with question to the genus Mawddachites Fletcher 2007.
Contribution of Morphometrics to the Systematics of the Ordovician GenusNeseuretus(Calymenidae, Trilobita) from the Armorican Massif, France
2013
The genusNeseuretusHicks, 1873 is the most abundant trilobite of the Ordovician siltite succession of the Andouillé and Traveusot Formations in the French Armorican massif. The systematics of some species ofNeseuretusis still unclear. Armorican and Iberian domains formed part of a distinctive paleobiogeographical province in the Ordovician and, while fiveNeseuretusspecies were defined in Iberia that follow each other through time, from the Middle to the Upper Ordovician, only oneNeseuretusspecies,N. tristani, has been identified in the Armorican massif so far. The discovery of new fossil deposits in the Ménez-Belair syncline has led to the identification and re-description of threeNeseuretu…