1904.] OSTEOLOGY OF THE ELOPID^ AND ALBIILID.E, 55 



in a forward direction ; and in Megcdops it has an inclination 

 intermediate between that of Elops on the one hand and that of 

 Alhula on the other. The laterally-directed process of the ecto- 

 pterygoid, which in Albula runs below the eyeball to meet the 

 upper edge of the suborbital bones, is feebly suggested, in both 

 Elop)s and Megalops, by a nai'row, laterally projecting ledge of the 

 ectopterygoid. 



The lateral temporal fossa is roofed over in Elops, Alhula, and 

 Bathythrissa, but in Megalops the lateral temporal groove is broad 

 and shallow, and has no roof. The interorbital septum is com- 

 pletely bony in Albula, but it is largely membi'anous in the other 

 genera under consideration. The eye-muscle canal has a posterior 

 opening in ElojJS and Alhula, but ends blindly in Bathythrissa, 

 and is blind in one specimen of Megalops, although opening in the 

 other two. The ethmoidal region is elongated in the Albulidse, 

 but not in the Elopidfe ; and the palatine has two articulations, 

 one in advance of the other, whereas the articular head is single 

 in the Elopidfe. While in the Albulidte the ethmoidal rostrum 

 projects in front of the mouth, in Elops, and more particularly in 

 Megalops, the lower jaw projects in advance of the upper. 



The supratemporals in the Elopidfe are large, thin scales of bone, 

 which meet in the dorsal median line of the head, without forming 

 a suture ; in the Albulidfe the supratemporal is more laterally 

 placed, is smaller, and has more the triradiate character so common 

 among Malacopterygian fishes generally. The bi-anchiostegal rays 

 are 32-35 in Elops, 23-25 in Megalops, 15 in Alhida, and 6 in 

 Bathythrissa. The spicular bone present in addition to the true 

 first pharyngobianchial in the Elopidfe, is wanting in the 

 Albtdidse. 



Bemarks on the Morphology of the Skull in the Lower 

 Teleosteaii Fishes generally. 



In this section of the paper are oflfered some remarks, generali- 

 sations, and criticisms of published accounts of the skulls of fishes, 

 based mainly upon an examination of the following species. 

 Most of the skulls were specially prepared for the purpose of this 

 research, it being found that the skulls of fishes as ordinarily 

 prepared do not lend themselves satisfactorily to svich a detailed 

 examination as that to which it was deemed desirable to submit 

 them in the present inquiry. 



Elops saurus. 

 Megalops cyprinoides. 

 A Ihida conorhynchus. 

 Bathythrissa dorsalis. 

 Morimyrops deliciosus. 

 Petrocephalus hane. 

 Gymnarchus niloticus. 

 Notopterus kapirat. 

 Hyodon alosoides^ 



ArapaiTna gig as. 

 Heterotis niloticus. 

 Phractolcemus ansorgii. 

 Chanos salmoneus. 

 Chirocentrus dorah. 

 Chato'essus erehi. 

 Clupea finta. 

 Dussumieria acuta, 

 Engraidis encrasicholus. 



Osteoglossum leichardti. \ Codia nasus. 



