312' BULLETIN OF THE UNITED STATES FISH COMMISSION. 



authority than Mr. McMurrich, who at ouce noticed it in the same periodical (Science, 

 No. 69, 1884), but his remarks possessed upon this point but little value, inasmuch as 

 he had not taken the trouble to examine a specimen before printing them, and therefore 

 had no material before him when he wrote. Nevertheless they were replied to by me 

 in another contribution to Science (vol. iii, No. 72, June 20, 1884) under the title of 

 "Osteology of Micropterus salmoides," and this time a figure of the left lateral view 

 of the cranium of this species of fish was published that showed the pair of free ribs 

 on the occiput. 



Moreover, in this communication the literature of the subject was reviewed, greater 

 detail added in regard to these fve&occipital ribs, pointing out that Mr. McMurrich was 

 entirely wrong in his conceptions of their morphology, and that "Dr.'Sagemehl, in his 

 valuable paper on the cranium of Amia [Morphologisclies JahrbucH, ix), is very explicit 

 in what he says about the coossification of the three vertebrae with the basi- occipital of 

 this ganoid ; and if this author had been aware of such a state of affairs as I here figure 

 in any of the Teleostei, he certainly would have brought it forward in connection with 



op^o :bo. 



Y\G. 1, — Left lateral view of cranium (if M. salmoides, showing a pair of ribs at the occiput; life size from 

 nature, by tlio author, from his own disdectioua. ^S. effi., supraetbmoid; J^r., frontal; Si]., squamosal; 

 Pa., parietal (not well in sight) ; Up. O., cpiotic; S. O., supraoccipital; Ft, O., pterotic; oc. r., occipital 

 ribs; vg.t foramen for vagus nerve; E. 0., oxoccipital; B. O., basi-occipital ; Op. O., opisthotic; Pr. O., 

 prootic; P(/.,po8tfrontal; As., alisphenoid; Bs., basisphenoid ; Fr.S., paraspheuold ; Pv/., prefrontal; 

 To., vomer. 



tlie discussion of that subject. They are two very significant facts, that these ribs in 

 Micropterus articulate beyond the vagus foramen and that they are apparently con- 

 stant. I have since found similar structures in a specimen of Orcynvs thynnus, and 

 rather suspect it in the Scombridce.^' 



The figure that illustrated this letter to Science reappeared in my memoir entitled 

 '• Outlines for a Museum of Anatomy," which was published by the Bureau of Education 

 at Washington, D. C. (Department of the Interior, 1885, p. 60, fig. 6). This figure is 

 introduced in the present memoir as fig. 1, as it illustrates a very important part of the 

 skeleton of the black bass. 



Beyond giving this cut, however, there was nothing especially added to our 

 knowledge of the osteology of this bass in my " Outlines for a Museum of Anatomy," 

 further observations being reserved until my more extensive memoir was published 

 by the U. S. Commission of Fish and Fisheries, in 1885, entitled "The Osteology of 

 Amia calva, including certain special references to the skeleton of Teleosteans." 



In this work very considerable reference was made to the skeleton of Micropterus 

 salmoides, and six figures were given in the plates illustrating it. Nevertheless the 



