NEW FISH FROM THE CRETACEOUS OF KANSAS. ICQ 



Concerning the exact extent of some of the elements entering in- 

 to the cotylus there has been some dispute, which this and some of 

 the mandibles of X. audax in our collection, will, I thmk, satisfac- 

 torily settle. Cope (Cret. Vert., p. 194) states that the articular 

 is distinct, wedge-shaped, and supports half of the cotylus. Hay 

 (1. c. p. 37) says that the bone called articular by Cope is not short, 

 but is continued forward in a long sword-shaped process, regarded 

 by Cope as being a part of the angular. The first of these Pro- 

 fessor Hay designates under the name of "autarticular" and the last, 

 "dermarticular. " After examining all of our specimens, I am con- 

 vinced that Professor Cope was correct, since in several of our best 

 preserved specimens a distinct suture is presented, extending 

 irregularly downward across this sword-shaped process at about the 

 point of "a, art," in Professor Hay's figure of this part (Fig. 5). 

 This suture is often indistinct, and is entirely obliterated in speci- 

 mens where this part is poorly preserved. 



Measurements of mandible: 



Length of alveolar border 215 mm 



Depth at coronoid process 118 " 



Length of symphysis 105 •' 



Depth of bone just back of symphysis 100 " 



Length of bone from cotylus 270 " 



There are fragments of several other bones, among which are the 

 ethmoid, prefrontal, palatine, several vertebrae, etc. The ehtmoid 

 is acutely pointed anteriorly, and the posterior suture, uniting it 

 with the frontal, is very dentate. The prefrontals are small, as are 

 also the malleolar portions of the palatines. The external tuber- 

 osities of these are less prominent than in A', audax. 



This specimen was obtained by Professor B. F. Mudge from the 

 Niobrara Cretaceous, four miles north of Gorham, Russell county, 

 Kansas. 



In this connection it might be well to make some changes in the 

 family of fishes called SaurodontidcB by Professor Cope (Proc. Am. 

 Phil. Soc. Vol. n, 1870, pp. 229-30). I have already divided this 

 family into two distinct groups, {Kans. Univ. Quart.. \'ol. vii, p. 

 23), each of which presents characters which I think are sufficient 

 to justify an independent existence, and which should be known 

 as the Saurodontidie and Ic/i/hyodccdidie, The first of these should 

 include the genera Sail/ odon and Saurocepha/iis the last, Xipliactiniis, 

 Ii-hlhvodfctei, and Gillictis. The two names have both been used be- 

 fore in connection with this group of fishes so fortunately the 

 nomenclature will not have to be burdened with new names. 



