Contribution to Our Knowledge of the Myxinoids

Abstract

EVER since Johannes Mtiller introduced the Myxinoids to the scientific world, interest in these primitive forms has continued unabated, both as regards their peculiarities of structure and function and their consequent position in the vertebrate series, and the interrelations of the different varieties among themselves. Owing to the wide geographical distribution of the Myxinoids, the relative scarcity of individuals, and the difficulty of securing material for study, especially the living animals, previous papers have been based upon the study of museum specimens, and our knowledge has, in consequence, been very incomplete. It was my good fortune to obtain, during the summer of I904, several hundred individuals of Bdellostonua dlomnbeyi Lac. in sound, healthy condition, which I kept alive in aquaria. I was able to provide conditions closely approximating their usual habitat, and, under these favorable circumstances, I kept them under constant observation for four months. The observations made have been checked by a study of the conditions of their normal habitat. This paper, therefore, is based mainly upon a study of living individuals in conditions approaching as nearly as possible the normal environment; and these notes are published in the hope of throwing some new light upon this interesting form, and for the purpose of correcting some erroneous statements that, through lack of means of observation, have gained currency. I wish to express my thanks to Dr. C. H. Gilbert, of Stanford University, who kindly placed at my disposal the facilities of Stanford's seaside laboratory at Pacific Grove, California; to