798 



SCIENCE. 



[N.S. Vol. XXII. No. 572. 



Nebr. The skeletal parts known at present 

 are the skull and mandible; the vertebral 

 series, complete as far as exposed, and articu- 

 lated; the pelvis and sacrum and the hind 

 limbs complete and likewise articulated; sev- 

 eral ribs attached to the vertebrae above and 

 to the sternum below, and a portion of one 

 scapula. The fore limbs are not yet in evi- 

 dence, but will doubtless be found either in 

 the material collected or else in the quarry, 

 which still showed numerous bones when work 

 was suspended. 



The most striking characteristic of the skull 

 is the four prominent horns, of which the 

 frontal pair rises upward and curves inward, 

 while the maxillary pair curves in the op- 

 posite direction. The maxillary horns, uni- 

 ting as they do at the base to form a common 

 trunk, divide the anterior nares into two por- 

 tions, the posterior of which may or may not 

 have been functional. However this may 

 have been, the margin of the opening seems to 

 have been roughened as though for ligament- 

 ous attachment. The dentition is complete, 

 though, consequent to age, the teeth are worn. 

 The premaxillse are edentulous. The upper 

 canines, which are strong and defensive, curve 

 noticeably outward. The lower canines have 

 migrated and assumed an incisiform function, 

 while the first premolars have in a like manner 

 become caniniform. Dentition: 



I. 



C. i, P. I, M. 



Measurements of the skull : Length of skull, 

 12| inches (325 mm.) ; distance between the 

 orbits across the frontals, 5 inches (128 nun.) ; 

 height of anterior horn cores above plane of 

 molars 6^ inches (166 mm.) ; spread of same 

 at summits 8:^ inches (210 mm.) ; height of 

 posterior horn cores above plane of molars Y| 

 inches (197 mm.) ; spread of same at widest 

 point 10 inches (254 mm.) ; width of palate 

 between molars IJ inches (32 mm.). 



No attempt should be made at this juncture 

 to fully define the genus. As to its affinities, 

 Syndyoceras seems to be remotely related on 

 the one hand to Protoceras of the Oligocene, 

 and on the other hand to the modern antelopes. 

 Syndyoceras may be placed for the present 



with the Protoceratidse, but it is doubtless 

 entitled to a place in a new family. 



Erwin Hinckley Barbour. 

 The University of Nebraska, Lincoln, 

 October 1, 1905. 



NOTE ON THE FUNCTIONS OF THE FINS OF FISHES, 



The exact determination of the function of 

 each kind of fin in fishes does not appear to 

 have been treated in a practical manner up to 

 the present time, and these organs are in: 

 general regarded as of little importance for 

 swimming. It occurred to me that a few 

 experiments might elucidate the question. 

 Unfortunately, I had and can have, at my 

 disposal, only fishes with fins but little devel- 

 oped and in small number, so that the facts- 

 which I am going to set forth have only a 

 relative bearing, and only naturalists having 

 sufficient material at their disposal will be 

 able to establish general rules. 



I had in the aquarium of the state college 

 three or four small specimens of Goodea atri- 

 pennis (a cyprinodont) four or five centi- 

 meters long, taken in a pond in the state of 

 Guanajuato. One of these individuals at- 

 tracted my attention by the entire absence of 

 its dorsal fin; whether it had disappeared by 

 accident or whether it had never existed was 

 not evident. Since the creature swam exactly 

 like those which were perfect, I thought of 

 investigating the function of this fin and also 

 of the others, both paired and single. 



No. 1. Individual without dorsal fin. My 

 preparator cut off the anal fin close to the 

 body. No difference whatever was observed 

 in the creature's movements. I conclude that,, 

 in Goodea at least, this organ exerts no influ- 

 ence in swiimuing or on the equilibrium. 



No. 2. I took another fish and had the pec- 

 torals and the ventrals amputated, that is to 

 say, the four members. At first the creature 

 appeared somewhat astonished and hesitating; 

 but at the end of an hour it finished by moving 

 deliberately and swimming as usual. The 

 pairs of fins appear, therefore, to have very 

 little if any bearing on locomotion. 



No. 3. A third Goodea served for the study 

 of the caudal fin. That alone was cut off. 



