22 Transactions of the 



rarf] forms of fish in kansas. 



BY B. F. MUDGE. 



About a year ago, there were sent to Hon. Alfred Gray, of Topeka, two fragments 

 of fish jaw, without any statement of where they were found. The singular and unusual 

 appearance of the teeth attracted my attention, and gave me not a little stvuiy to fix their 

 relation to other fossils. Being at Osage City soon after, I procured two similar speci- 

 mens, and learned that those of Topeka were from the same locality. The jaws were 

 from a Cestraciont Selachian — entirely new to science. It is well known that the shark 

 tribe, to which these belong, have no solid bones or any solid substance in the body, ex- 

 cept the teeth ; and consequently .the latter are the only parts of the body ever fossilized^ 

 or which now remain to give us a knowledge of their structure and habits. As the jaws 

 are cartilaginous, when the animal dies the ligaments holding the teeth together decay, 

 and they become separate, and are not found in regular position. In the present case 

 they are found in their natural and regular position. The jaws must have become im- 

 bedded in a firm clay, which retained the teeth together, after the cartillage decayed. 

 The teeth being palatal, or pavement, covered the wliole surface of the mouth, instead of 

 being arranged in rows at the edge of the jaws, and we now have them in their natural 

 arrangement. Many of the Cestracionls have no order in the position of their teeth ; 

 but in this specimen the rows are very regular, and must have numbered five hundred 

 and sixty (560) in a single jaw. The largest teeth — two and a half inches in basal 

 length — are found in the center of the mouth, and diminish in size as they approach the 

 front ; and the teeth also lessen in number toward the sides of the mouth. The best spe- 

 cimen contained over four hundred teeth in excellent order and preservation. A portion 

 of one side of the jaw was gone, but the regular position of the remaining teeth was such 

 that the number and situation of the missing one lumdred and sixty (160) were easily 

 calculated. 



Knowing the value and importance of the specimen, I immediately wrote to Prof. O. 

 St. John, who makes a specialty of the carboniferous fishes, in the museum of Cam- 

 bridge, under Agassiz. He requested a specimen for study. He writes me that the jaw 

 is remarkable, in showing teeth so unlike in different rows that paleontologists, when 

 finding them separately, have described the teeth now in one as belonging to tw6 genera 

 and three species. He also adds that the lamented Agassiz stated on one occasion that if 

 ever a perfect jaw of these ancient, extinct Cestracionts should be discovered, it would be 

 found that several species now separated constitute but one. Thus ever true to nature 

 was this great naturalist. He finds that these Cestraciont jaws throw much light on the 

 earliest fossil fish, and the lowest type of fish of the present day. The affinities in this 

 case are .so diflferent from what was previously known, that he has considered it a new 

 genus and named it after Prof. Agassiz — Agazodus. 



The most remarkable species of fish which we have found, the present season, are of a 

 genus new to me, and I think to science. They are armed with a long, strong weapon at 

 the extremity of the upper jaw, something like that of a sword fish, but round and 

 pointed, and composed of strong fibres. The jaws are provided with three kinds of teeth. 

 On the outer edge is a row of large, flat, cutting teeth, somewhat resembling those of a 

 shark. Inside, and placed irregularly, are small, blunt teeth; while in the back portion 

 of the palate is the third set — small, sharp and needle-like in shape, forming a pavement. 

 The jaws are also fibrous, like the snout. There are three species of this genus. Prof. 

 Marsh ha.s them for critical scientific examination. 



