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THE NASAL APPARATUS IN DIPNOI, WITH SPECIAL REFERENCE TO PROTOPTERUS
Author(s) -
THOMSON KEITH STEWART
Publication year - 1965
Publication title -
proceedings of the zoological society of london
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 96
eISSN - 1469-7998
pISSN - 0370-2774
DOI - 10.1111/j.1469-7998.1965.tb02015.x
Subject(s) - anatomy , snout , biology
An investigation is made of the homology of the nasal apparatus of the Dipnoi, in order to determine whether the posterior naris is homologous with the choana of tetrapods or with the posterior external naris of fishes. The ontogeny of the nasal capsule of Protopterus is described in detail. The nervous and venous systems of tho snout region of Protopterus are also duscrbed. It is found that whereas the pattern of the nervous and vascular systems is very similar in all Dipnoi, the structuro of the nasal capsule in the Lepidosiren‐Protopterus stock differs greatly from that of the Neoceratodus stock. the homology of the various components of the depnoan nasal coasule is revised and it is shown that there are no evidences of a direct relationship of the Dipnoi with the tetrapods. It is further concluded that the posterior naris of Dipnoi is homologous with the posterior external naris of fishes.