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Show 1882.] THE STRAITS OF MAGELLAN. 651 other hand, there is no such interspace, in consequence of the different form of tbe basal joints, while the distal edge of the succeeding joints is provided with a delicate spinous process, which appears to be absent from the northern form. The accompanying drawings represent the second pinnules of A. eschrichti (A), and its variety (B). A difference of this kind can hardly be taken to be specific, though, of course, there is a " personal equation " in zoology which renders it within the bounds of possibility that some brother naturalist m a y look upon it as having a higher distinguishing value than I a m inclined to ascribe to it. Morphologically, the forms appear to belong to the same species ; and the differences are best marked, in the language of systematic zoology, by speaking of the new Crinoid as Antedon eschrichti, var. magellanica. B It is not for the first time that attention has been directed to a resemblance between an arctic and an antarctic form; but never, perhaps, has the resemblance been so difficult of explanation. For myself, I feel compelled to confess that by no effort of the imagination can I figure to myself the passage of this fixed form oyer so wide a tract of sea and coast. If such has taken place, it will have to be allowed that the larva can hardly be free for so short a time as is the case with the best-known British species. Nor can it be well |