I04 NEW YORK STATE MUSEUM 



1897 Macropetalichthys sullivanti and M. rapheidolabis C. R. 



Eastman. Am. Nat. 31:493-99, pi. 12 

 1901 Macropetalichthys sp. B. Dean. N. Y. Acad. Sci. Mem, v. 2, pt 3, 



p. 119, text fig. 12 



Head shield suboval, regularly arched from side to side, attaining a 

 maximum length of about 25 cm, and width across the posterior border of 

 about 17 cm. Ornamentation consisting of fine, closely crowded stellate 

 tubercles, sometimes displaying concentric arrangement. Of the two pairs 

 of small centrals, which are separated from each other by the median occip- 

 ital, the anterior takes part in the orbital border and is not traversed by 

 sensory canals. Pineal plate pierced by an inconspicuous foramen, and 

 apparently equivalent to the so called anterior median element or " meseth- 

 moid " of Neoceratodus. Parasphenoid much expanded in front, posteriorly 

 produced, resembling in a general way that of Ctenodipterines and Sire- 

 noids, but considerably less ossified. 



Preorbital sensory canals lyrate, and confluent in the middle line with 

 the sharply angulated exocciplto-central system. The postorbital canal 

 extends from the inferior border of the orbits to the center of the marginal 

 plates, where it turns abruptly inwards and continues in a straight line to 

 meet the exoccipito-central canal at the point of its angulation. The latter 

 disappears beneath the surface of the external occipital plate close to the 

 hinder margin of the head shield. 



Speaking entirely within bounds, it is not too much to say that the 

 characters of this long misunderstood genus and species fail of comprehen- 

 sion, or at least of satisfactory analysis, save as they are brought into rela- 

 tion with those of modern Dipnoans, and interpreted through comparison 

 with them. Many students have puzzled over the cranial osteology of 

 Macropetalichthys and the allied genus Asterosteus, of which only the 

 median series of plates are known ; but accumulation of details has resulted 

 only in greater perplexity. Were a moral to be drawn from this state of 

 affairs, and others like it, it would be this : However diligently facts may be 

 collected, however attentively studied, they possess of themselves no intrinsic 

 value ; their usefulness lies only in the measure that we are able to appre- 



