130 RECORDS OF THE AUSTRALIAN MUSEUM. 



rounded iiotcli, which Traquair considers to represent the position 

 oi the anterior nasal opening. The author concluded his descrip- 

 tion in these words — "Our fossil is certainly ui^ithev J) ipter us nov 

 Ceratodus ; Cheirodns is known only by its teeth ; and as to 

 Ctenodus, the front of the head has not yet been discovered, so 

 that all evidence is wanting to connect it with that genus. It 

 seems, therefore, in these circumstances, best to frame a new 

 genus for its reception." 



Dr. Traquair's description of this remarkable fossil seems even 

 now to be practically all that is known of it, for Dr A. 8. Wood- 

 ward writes- of GiuuirhijncJms as "a provisional genus at present 

 incapable of definition, comprising large PaUeozoic Dipnoan fishes- 

 in which the extremity of the snout (as also presumably all the 

 external lieadbones) is enveloped in a thick layer of punctate 

 ganoin." 



The specimen discovered Ijy Mr. Siissmilch is externally nmch 

 more complete than that figured l)y Traquair. Tt consists of the^ 

 snout and most of the plates of the cranial buckler covered with 

 glossy ganion densely and minutel}" pitted, and separated from 

 one another V)y fairly-well marked sutures. This cranial shell, '1 

 mm. thick along the posterior edge, is strongly arched from side 

 to side, but unarched between the aiiterior and posterior extre- 

 mities, so far as preserved. In its present condition it measures 

 four inches from end to end, and three inches trans\'ersely at its 

 greatest width, without following the curve. The plates are moi'e 

 or less distinguishable to within one inch of the snout extremity, 

 this portion lieing, as in the corresponding but much larger area 

 of (j. /roodian-di, devoid of sutures, and the punctfe of the 

 polished surface interspersed with others ( f a larger diameter. 

 The snout is fairly perfect, but the posterior end of the specimen 

 is fractured and imperfect. Dr. Traquair's description of the 

 fore-under surface can almost be applied to tlie corresponding- 

 part of ^fr. 8iissmilch"s fossil. ^^'e see the arched and flattened 

 front of the snout and margin of the upper lip, the rounded 

 superior eih^e of the former fading into the surface of the shield. 

 On this labial margin the ganoin has been worn off, but leaving^ 

 traces of punctje larger than any of those on the upper surface. 

 The central portion of the lower margin of the lip, wlien viewed 

 from the front, is convex, with on each side a shallow rounded 

 notch, the anterior nasal opening according to Traquair. The 

 median indentation of this lip edge in (r. iroodnrtrdi is not visible 

 in (r. stisxniih-hi until the specimen is turned completely upside- 



■' AVoodwnrd- lii-it. Miis. Cat. Foss. Fislios. Tt. ii., 1891, \\ 245. 



