BY F. KATTE, ING. DES ARTS ET MANUF., PARIS. 1083 



Society, the specimen being beautifully preserved and apparently 

 one of the Palwoniscidce, but of puzzling affinities. I have, however, 

 not yet found sufficient works of reference on the subject. 



Although the fins provided with fulcra, and the scales remind us 

 of some species of Palceoniscus, the tail does not seem a perfectly 

 heterocercal one, and resembles, in some respects, and on a superficial 

 examination, that of a fish widely separated from it in other respects, 

 viz., Lepidotus, which is understood to have had an homocercal 

 tail. The rays of the tail and fins ai*e divided at about half their 

 length into fan-shaped expansions, as shown distinctly in Agassiz's 

 fig. of Lepidotus (Vol. 1, tab. C), in Megalurus (Vol. 1, tab. E), 

 in some species of Palceoniscus, and in other fishes. 



With this fish are found some others of the same family, and 

 the well-known Cleithrolepis granulatus of the Hawkesbury 

 sandstone. 



I may also add that the plants found with these fishes include 

 also a specimen of Thinnfeldia odontopteroides, and that the genera 

 Jeanpaulia and Cycadopteris or Lomatopteris, to which they are 

 supposed to belong, are considered as Jurassic in Europe. The first 

 one, however, is also found in the Khsetic, which is considered as 

 Triassic ; and the second may likewise have come into existence in 

 the Trias also, (since it would not be the first instance where plants 

 have failed to determine the age of a formation) if more importance 

 than necessary was given to its being considered Jurassic in Europe, 

 as above stated. 



EXPLANATION OF PLATES. 



Plate xv. 

 Fig. 1. —Proetus Ascanius (?). x 2. 



Fig. 2. — Proetus Ascanius (?). A smaller specimen, x 2. 

 Fig. 3. — Head of same without the movable cheeks, x 2. 

 Fig. 4. — Pygidium (probably of same species), x 2. 

 Fig. 5. — Part of body of Acidaspis VerneuiU (?) drawn from a specimen 



(the largest Australian trilobite) in Mr. J. Mitchell's collection, 



Bowning. Natural size. 

 Fig. 5 bis. — Head of Acidaspis VerneuiU (?) corresponding to a smaller 



specimen. 



