. Bulletin - United States National Museum. Science. 294 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. Nor are the relative numerical proportions of the two classes to each other any more significant. With the evidence at his command Vanhoffen had every reason to use the number of otoliths to each otocyst as a systematic character. But facts afforded by the present specimens show that it can not be given so much weight. Thus in the larger Philippine example I have found otocysts with 1, 2, 3, and 4 otoliths, usually two large and the others small; and in the smaller one, instances with 1, 2, an
. Bulletin - United States National Museum. Science. 294 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. Nor are the relative numerical proportions of the two classes to each other any more significant. With the evidence at his command Vanhoffen had every reason to use the number of otoliths to each otocyst as a systematic character. But facts afforded by the present specimens show that it can not be given so much weight. Thus in the larger Philippine example I have found otocysts with 1, 2, 3, and 4 otoliths, usually two large and the others small; and in the smaller one, instances with 1, 2, and 3. The only character which stands the test of critical examination, as I have previously pointed out, but which Vanhoffen (1911) has not employed at all, is the relation between the number of otocysts and that of tentacular organs, both large and rudimentary. The recorded numbers are as follows: virens Bigelow virens Maas Philippine specimen rribcngha Agassiz and Mayor mbengha Vanhoffen carolinae Mayer. Otocysts. 32 32 38 32 4S 64 We have every reason to assume that the numerical conditions in the Atlantic carolinae described by Mayer (1910) are fairly con- stant in the adult, for he has found it very abundant on two occa- sions at Charleston, South Carolina, and has also taken it at the Tortugas. The table, then, shows that in all the Indo-Pacific speci- mens, irrespective of locality or of exact stage of development, there are many more tentacular structures than otocysts, often twice as many. On the other hand, in all the Atlantic examples of which we have any account the number of otocysts is as great as that of the tentacular structures. We have here something tangible. It is, of course, possible that further studies may reveal speci- mens connecting the two types; but the same possibility is present in the case of every difference which could be used us a specific character. We have no right to assume that this will happen. On the contrary, when we find that all the ev
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