CRANIAL OSTEOLOftY OP THE 0STE0GL0SSID3S. 253 



(Proc. Zool. Soc. 1895, pp. 302-310). When, during the course 

 of the investigation, it was found that this articulation occurred 

 in Arapaima and Seterotis and in Osteoglossimi hicirrliosum and 

 Osteoglossum Leichardti, as well as in Osteoglossum formosum, it 

 became of interest to ascertain whether it was present in Pantodon 

 and Phractolcdmus, isolated genera belonging to families of 

 their own, but usually associated with the Osteoglossidae. As is 

 shown ia the sequel, the articulation is present in Pantodon^ but 

 not in Pliractol(Sinus. 



I have to acknowledge my indebtedness to Mr. G-. A. Boulenger 

 for oftering to me facilities for the examination of the skulls of 

 Pantodon, PhractolcBmus, Arapaima, Heterotis, and Osteoglossum 

 hicirrJiosum in the British Museum collection, and to Prof. G. B. 

 Howes and Prof. T. W. Bridge for the loan of skulls of Osteo- 

 glossum Leichardti and Osteoglossum formosum respectively. 



OSTEOGLOSSI T> M. 

 OsTEOGLOSStrM. 



figures of the top and side of the skull of Osteoglossum 

 formosum, and a few words of explanation, are given by Miiller 

 and Schlegel (Temminck's Verh. Nat, Ges. Nederl. overz. bez., 

 Zool., Leiden, 1839-44, Pisces, pi. i. figs. 2 & 3, and pp. 5 & 6). 

 A few remarks on the skull-bones of the same species of Osteo- 

 glossum,^ are included in Hyrtl's account of the skull of Heterotis 

 PJhrenhergi (Denkschr. Akad. Wiss. Wien, viii. 1854, pp. 73-76). 

 Bridge's account of the skull {Osteoglossum formosum, Proc. 

 Zool. Soc. 1895, pp. 302-310), though more detailed, is incom- 

 plete, being limited to " certain features," notably the articula- 

 tion between the parasphenoid and the hyopalatine arch. 



OSTEOGLOSSTJM LeICHARDTI. 



The skull here described is one specially prepared for the 

 purposes of this investigation from a specimen belonging to the 

 Royal College of Science, London. 



Cranium (PI. 30. figs. 1, 2, and 3). — The parietal bones touch 

 one another in the median line of the head. The surface of the 

 anterior two-thirds of each is sculptured, the posterior third lies 

 at a lower level and is not sculptured. The frontal bones are 



* The species is identified as formosum by Boulenger (Ann. Mag. Nat. 

 Hist. (7) Tiii. 1901, p. 514). 



