THE SKELETON OF THE BLACK BASS. 
By Dr. R. W. SHUFELDT. 
Upward of twenty years ago a special interest was taken by me in the osteology 
of the large-mouth black bass (. Micropterus salmoides) from having discovered in the 
skeletons of one or two specimens of that species a pair of free ribs articulating with 
the base of the skull or occiput. As this peculiar anatomical character had never 
been noted by me before in any of the true bony fishes ( Teleostei ), it was at the time 
deemed worthy of scientific record, and so, under the title of “Osteology of the large- 
mouthed black bass (Micropterus salmoides ),” there was printed in Science, of Cam- 
bridge, Mass., May 2, 1884, a brief account of this interesting point in the skeleton 
of Micropterus. 
It was there stated that this peculiarity “consists in a pair of freely articulated 
ribs at the base of the occiput. Their heads are received in a shallow facet on either 
side situated just above and rather internal to the foramen for the vagus nerve. 
Immediately below each rib occurs the projection of bone that bears upon its entire 
posterior aspect one of the pair of articular condyles for the first free vertebra of the 
spinal column. Still beneath these condyles is seen the conically concave facet for 
articulation, with a similarly formed surface occurring on the centrum of the vertebra 
just mentioned, and the one which I believe would be described as the atlas.” This 
pair of ribs is directly in sequence with the abdominal ribs on either side. Their 
occurrence in this situation might be accounted for by saying that several of the 
anterior vertebrae of the column had been absorbed by the occipital elements. Mr> 
Bridge found such a condition in Amia, though no free ribs were present (. Journ . Anat. 
and PJujs., xi, 611, London, 1877). In further commenting upon this it was added 
that a in the cranium of Micropterus , however, I should think that this would be highly 
improbable. Both the first and second vertebra of the spinal column of this bass 
support bach a pair of free ribs, and a mid-series of the other abdominal ribs bears 
epipleural appendages. Dr. Gunther states, in his account of the osteology of the 
Teleostei, in the article ‘Ichthyology’ of the Encyclopedia Britannica (vol. xii, 9th ed.), 
that ‘the centrum of the first vertebra or atlas is very short, with the apophyses scarcely 
indicated. Neither the first nor the second vertebra has ribs.’ I have a yellow perch 
(Perea flares cens) in my possession where both of these vertebrae support a pair of free 
ribs.” In conclusion, I added that “ should an examination of the young of the black 
bass show that none of the anterior vertebrae of the column were included with the 
occipital segments, but that these ribs are truly occipital ribs, then they become of 
interest from several points of view.” 
This discovery was made in March, 1884, and, as has been noted above, was 
published the following May, and attracted the attention of no less a distinguished 
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