112 NEW YORK STATE MUSEUM 



Formation and locality. Onondaga limestone ; Leroy, N. Y. Colum- 

 bus and Delaware limestones; Ohio. " Corniferous" limestone ; Indiana 

 and (?) Canada. 



Macropetalichthys agassizi (von Meyer) 



1845 Asterolepis hoeninghausii L. Agassiz {errore). Poiss. Foss. V. G. R. 

 p. 130, 147, pi. 30a, fig. 10 



1846 Placothorax agassizi H. von Meyer. Neues Jahrb. fiir. Min. p. 596 



1847 Placothorax agassizi H. von Meyer. Palaeontogr. 1:102, pi. 12, fig. i 

 1855 Physichthys hoeninghausii H. von Meyer. Palaeontogr. 4: 80, pi. 15, 



fig. 1-5 (non figs. 6-1 1 ) 

 1857 Agassichthys agassizi J. S. Newberry. Nat. Inst. Bui. p. 119 

 1873 Macropetalichthys agassizi J. S. Newberry. O. Geol. Sur. Rep't, 



Pal. V. I, pt 2, p. 291 

 1895 Macropetalichthys agassizii A. von Koenen. Abhandl. Ges. Wiss. 



Gottingen, 40: 22, pi. 4, fig. 3 



Reference has already been made to the fact that the type of Hermann 

 von Meyer's Physichthys hoeninghausii is now the property of 

 the Museum of Comparative Zoology at Cambridge, Mass. Although 

 incomplete, the part that is preserved shows several of the cranial elements 

 very distinctly, and also the narrowed posterior portion of the parasphenoid 

 which supports the notochordal sheath. This is deeply channeled in the 

 median line for the passage of the notochordal sheath, and is concentrically 

 striated in the same manner as the vertical lamina which descends from the 

 posterior margin. The sheath itself exhibits no trace of segmentation, and, 

 like that in the type species, is of remarkably small diameter. 



Formation and locality. Middle Devonic ; Eifel district, Germany, 



Genus asterosteus Newberry 

 An imperfectly definable genus, known only by the median series of 

 cranial plates, but apparently closely approaching Macropetalichthys in 

 structure. Ornamentation consisting of large, rounded, stellate tubercles, 

 very irregular in size and arrangement ; sensory canals indistinct ; a pineal 

 foramen, and also a pair of large oval openings of unknown significance 

 present in the interorbital region. 



