ON TWO NEW FORMS OF POLYODONT AND GONORHYNCniD FISHES. 163 



illary bones, as those of the dentaries are too acute. Determinable palatine bones are not visible 

 ill the spec'inicn. The bases of the teeth are round and are close together. They measure .000"'"". 



The body of the originally described individual presents the following cliaracters : 



Intenieural basilar bones 10 to 18; body slender at dorsal tin and contracted at caudal pe- 

 duncle. Dorsal and anal fins moderate, caudal very large, with strong anterior fulcral rays. The 

 posterior fulcra are elongate aud subcylindric, and overlap each other extensively. Anteriorly 

 they flatten so as to approach the form seeu iu the paddle-fish, but these are well distinguished 

 from the fulcral scuta iu front of them. The latter are longitudinally oval, and have a groove 

 along the middle line. The caudal h.-emapophyses are short and expanded distally. They soon 

 disappear in the superior lobe or axis of the caudal fin. I count nine to the anterior more or less 

 cylindric ones. At the base of the inferior lobe of the caudal fin are five fulcra lying on each 

 other, the inferior ones more flattened than the superior ones, all with acute posterior apices. 



The scales are subquadrate in form aud measure about a millimeter each way, including the 

 spines ; they are uowhere in contact and are more widely separated anterior to the dorsal fin than 

 posterior to it. The sides of the axis of the superior lobe of the caudal flu are covered with closely 

 packed oat-shaped scales. 



Length from notch of caudal flu to line of anterior base of dorsal, M. .170 ; depth at anterior 

 base of anal, .060; depth of caudal peduncle, .035; length of inferior lobe of caudal, .110. Length 

 of an iuterneural basilar, M. .012 ; of an interhaemal basilar, .014. Probable number of dorsal radii, 

 24, Anal fln imperfect. 



NOTOGONEUS OSCULTJS Cope, American Naturalist, Nov., 1885, p. 1091. 



Family char. — The location of this genus is rendered quite possible by the excellent preserva- 

 tion of two specimens of the typical species which have come into my possession. The form is 

 plainly isospondylous, and belongs to a family in which the parietal bones are separated by the 

 supraoccipital ;* the superior border of the mouth is formed by the premaxillary boue exclusively; 

 the pterotic and intercalary bones are normal ; the caudal fln is homocercal, and the dorsal and anal 

 fins posterior, and with few radii. There is no indication of adipose fln under most favorable cir- 

 cumstances for its preservation, and the branchiostegal rays are three or four. These characters 

 place the genus within the limits of the family Gonorhynchidse, of which but a single genus aud 

 species have been hitherto known. This flsh is now living iu the waters of the Cape Colony of 

 South Africa, and of South and West Australia, and, it is said, also iu those of Japan. The dis- 

 covery of this type in the Eocene beds of North* America is a notable addition to ichthyological 

 science. It is parallel with the occurrence of the family of the Osteoglossidte in the same forma- 

 tion, a family also now couflned to the Southern Hemisphere. It will be seen on comparing the 

 generic characters that this genus is very nearly allied to the living one. 



GJiar. gen. — Body covered with scales whose borders have a fringe of rather long spines. 

 Mouth small, probably a barbel on each upper lip, as a spicule of bone projects downwards and 

 backwards from each side of the end of the muzzle. No traces of teeth iu the jaws or on the 

 pterygoid or hyoid bones. An oval body at the superior extremity of the posterior branchihyal 

 arches below the vertebrje. Caudal fln bifurcate. 



In the above diagnosis the only character which separates this genus from Gonorhynchus is 

 the absence of the dental apparatus of the hyoid aud pterygoid bones which characterizes the 

 latter. It is probable that if the suprabranchial mass above referred to be the homologue of the 

 similar organ in Gonorhynchus, there is here also an important differeuce. In Notogoneus 

 this is sacciform. In Gonorhynchus it is lamina. The muzzle of the fossil species is not so 

 prominent as iu the recent one, but this being a matter of proportion only, may be only a specific 

 character. The addition of a new genus to a family hitherto so little represented is a circum- 

 stance of interest, but not entirely unexpected. It is iu generalized families like this one and the 

 Galaxiidae, that we are to look for additions in the faunse of the early Tertiary aud Mesozoic periods. 



Some characters which do not enter the speciflc category may be here referred to. The max- 

 illary boue is bordered on its entire anterior edge by the premaxillary, and has no supplementary 



' I fiod on renewed examination of tlie Gonorhynehua greyi that the frontal bone8 extend far backwards, so that 

 parietals are entirely separated by the supraoccipital. 



