A new nematode species, Guyanema longispiculum sp. n. is described from the abdominal cavity of the freshwater armoured catfish, Loricariichthys hrunneus (Hancock), from two localities in western Venezuela. It differs from all hitherto known members of the genus in having unusually long spicules (0.480-0.609 mm) and from individual species also by other morphological and biometrical features. It is characterized by the presence of eight cephalic papillae arranged in two circlets, localization of deirids anterior to the nerve ring, a conical, undivided tip of the tail in both sexes, four pairs of preanal and six pairs of postanal papillae in the male, and a markedly elevated vulva in the female. A key to species of Guyanema is presented.
The paper presents a historical review of development of the Tessar objective, probably the most known photographic objective, which is widespread in the photographic and reproduction world. Nowdays it is still manufactured in many companies, especially as a standard photographic objective for both professional and amateur devices, and as an objective for enlargers as well. and Práce ukazuje vývoj objektivu TESSAR, pravděpodobně nejznámějšího fotografického objektivu, který dosáhl nebývalého rozšíření ve fotografické a reprodukční technice. Do dnešní doby se stále vyrábí různými firmami, a to zejména jako standardní fotografický objektiv pro profesionální i amatérské fotopřístroje a jako objektiv pro zvětšovací přístroje.