250 IOWA GEOLOGICAL SURVEY 



is at hand, this fauna will be made the basis of one number of 

 'Kinderhook Faunal Studies'."* 



Bearing in mind the remote geological antiquity of the new 

 Coelacanth we have just described, it is suggestive to note that 

 its totality of characters by no means indicates a primitive mem- 

 ber of the group, but on the contrary bespeaks a typical species 

 as completely developed as any subsequent form with which we 

 are acquainted. In this respect it resembles the only well known 

 British Coelacanth of an age anterior to the Coal Measures, this 

 being C. huxleyi, from the Calciferous sandstones of southern 

 Scotland. Palaeontologists are well aware that the oldest known 

 Coelacanths from the western hemisphere are of Coal Measure 

 age, and are represented by poorly or indifferently preserved 

 material. In all, but four species of Coelacanthusf proper, and 

 three of Cope's genus Peplorhina, are recorded from a few 

 localities in Ohio and Illinois. 



It is now in order to present a more detailed description of 

 the new Kinderhook form. The characters of specific value 

 which it displays may be enumerated as follows: (1) The deli- 

 cate spiniform ornamentation of the operculum and cheek plates, 

 together with the form and disposition of the latter; (2) the 

 peculiar form of the mandibular ramus; and (3) details of scale 

 ornament; and (4) prominence of the lateral line canal. Owing 

 to the decidedly imperfect preservation of most of the fin struc- 

 tures, it is impossible to say in what respect, if any, these differ 

 from the normal type. The cranial structure, however, offers 

 a number of interesting points of comparison with other forms, 

 as will be immediately pointed out. 



The roofing-bones of the skull are missing in the type speci- 

 men, and that portion of the head in advance of the orbits has 

 been fractured in such manner as to strip off the maxillary and 

 other external facial elements, exposing at the same time the 

 anterior spatulate portion of the parasphenoid, together with 



* Earlier numbers of these Studies, the second one dealing with the fauna of the 

 Chonopectus sandstone at Burlington (immediately overlying the fish-bearing bed 

 No. 1) , are published in vols. 9 and 10 of the Transactions of the St. Louis Academy 

 of Science. 



t Certain of these types are now preserved in the American Museum of Natural 

 Historv in New York. Cf. Hussakof's "Catalogue of Fossil Fishes," etc., pub- 

 lished 'in vol. 25, of the Bull. Amer. Mus. Nat. Hist., June, 1008. 



