1869.] -^^^ [Cope. 



Measurement. 



In. Lin. 



Leiigtli of centrum 1 



Width " " betAveen lateral septa 7.1 



Depth of cup 8.4 



Width " " 7.9 



Depth of ball 8.5 



Length base (?) pleurapophysis 6.8 



" " neurapophysis 7. 



Width neural canal (external, front) 5.2 



" " " (internal, behind) 2.8 



The large cells are exposed by the fractures of portions of the bone. 

 The largest are at the posterior base of the haemal arch and at the sides 

 of the articular ball, one of the former 1.5 line in diameter. These meas- 

 urements indicate a gar of six feet in length, if of usual proportions. 



The specimen on which this species is established was found by the 

 writer on a pile of miocene marl on the plantation of Nathan Edgerton, 

 in Wayne county, North Carolina. Its interstices are filled with a hard 

 clay matrix, similar to that which adheres to cetacean remains in the hard 

 stratum in the lower part of the miocene shell-bed of that region. 

 Whether it were originally transported from a cretaceous stratum, is not 

 readily ascertainable, as the porous and dense structu^re of the bone re- 

 ceives fractures rather than rounding from transportation, which cannot 

 be distinguished from those miocene specimens. The color is black. 

 Mus. Cope. 



Ckommyodtjs ireegtjlaris, Coj)e. Pliacodus irregularis, Cope Proc. 

 Bost. Soc. N. Hist. 1869. 



The name Phacodus having been given by Dixon to a genus of fishes 

 allied to Pycnodus, from the Tertiary of Sussex, England, the present 

 genus must receive a new name. 



ISCHTODUS LATEBIGERUS, Gope RJ). IIOV. 



This species is of aboiit the same size as the I. mirificus Leidy, and presents 

 marked characters. Its extremity is much prolonged, and more flattened 

 than in any other species from the United States. The outer and concave 

 side is elevated by the extent of the anterior exterior crests, which is also 

 remarkably prolonged beyond the dental area which it supports. When the 

 tAvo mandibular rami are in place, it foUoAvs from the above, that the me- 

 dian line of the beak is occupied by a deep concavity, Avhich is walled in by 

 the high anterior outer crest. The posterior outer crest is also well de- 

 veloped, and is also prolonged acutely beyond the posterior dentinal area. 

 The latter is oval and very small, less than .33 the anterior. The ante- 

 rior is long and narrow ; its middle marks the anterior extremity of the 

 great inner area. The latter is large in all dimensions, and is undivided. 

 Below it is a slender intero-lateral column. The mandible is thoroughly 

 and regularly curved outwards and backAvards. The external terminal 

 column is largely developed vertically. 



This species approaches the I. smockii m. but is double the size, is 



