[Organization of the nasal septum bone and its homologue. II. Os alare et systema palatinum axiale (in fish)].

The aim of these investigations was differentiation and systematization of elements of osseous medial palate and attempt to discover of spheno-orbital bone homologue in fish (os orbito-sphenoideum). 50 adults fish heads of carps, perch , tench , common pikes and trout were examined. The methodology was described elsewhere. It was stated that in examined animals the pair premaxilla was divided into three parts: corps, palate and frontal process. The para-sphenoid bone was also a double biomechanical system, composed of septum homologue and transverse lamina , the same as in other vertebrates. All above mentioned parts create the palatal axial system. The orbital-sphenoidal bones in fishes are homologue to the sphenoidal bone in birds.