256 EDWIN CHAPIN STARKS. 



without backward extending processes on median line of snout ; 

 maxillaries forming lateral margin of mouth ; two toothed and 

 two toothless superior pharyngeals present on each side ; post- 

 temporal connected to the epiotic by a ligament ; l nearly meet- 

 ing its opposite fellow just behind the occipital region ; supra- 

 clavicle normal in size ; post-clavicle a single ray of bone ; hy- 

 percoracoid foramen only notching the lower edge of hyper- 

 coracoid ; 2 actinosts rather elongate, all ending against hypo- 

 coracoid or in cartilage opposite that bone ; pelvic bones without 

 an overlapping spur ; upper end of shoulder girdle attached by 

 ligament to first vertebra ; parapophyses normally developed 

 only posteriorly ; the haemal spines which support caudal at- 

 tached by suture to their centra ; posterior vertebras with a very 

 decided upward bend ; 3 vent normal in position. 



Family ESOCIDyE. 



Characters as indicated by Esox reticulatus. 



Cranium long and slender, with a narrow projecting rostrum ; 

 interorbital septum single ; myodome short not opening pos- 

 teriorly ; the prootic shelf above not nearly reaching to mouth 

 of anterior opening to brain case ; parietals extending over a deep 

 cavern to pterotic ; suborbital present ; a lateral wing extending 

 upward from parasphenoid barely reaching to alisphenoid ; sep- 

 tomaxillaries 4 present between ethmoid and vomer ; vomer large, 

 reaching anterior to parasphenoid ; nasals present ; basisphenoid 

 extending upward from parasphenoid, Y-shaped and unattached 

 above ; opisthotic absent ; palatine joined to prefrontal by a slen- 

 der process ; anteriorly without a process hooking over maxillary ; 

 a wide open space between the hyomandibular and the preoper- 

 cle opposite the middle of the latter ; premaxillaries widely 

 separated from each other by the rostrum ; maxillary with a 



1 In a specimen of Esox 40 cm. in length the ligament is 4 mm. long. In Umbra 

 it is comparatively as long. 



2 See exception under description of Esocidse. 



3 In Esox the narrow hypural plate is placed at an angle of about 45 degrees, and 

 the haemal spine from the preceding vertebra runs horizontally back to the base of the 

 middle caudal rays. 



* E. P. Allis, Jr., discusses the septomaxillaries and the paired ethmoid of Esox, 

 in a paper entitled " On Certain of the Bones of the Cheek and Snout of Amia calva," 

 Jour, of Morph., Vol. XIV., No. 3, 1898. 



