602 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVII. 



SYNOPSIS OF CHARACTERS OF THE BERYCOIDEA. 



Orhitosphenoids present; meeting each other at their inner edges, 

 and joined at an angle, either by simple suture or by ankylosis. Exoc- 

 cipitals broadly joined to each other, and to the basioccipital, together 

 forming a simple concave occipital condj'le. The pit of the basioccipi- 

 tal above the middle of the bone, or near the middle of the entire con- 

 dyle/' Atlas more or less modified or convex to tit the occipital condyle; 

 never deeply concave; the pit more or less obliterated, never deep 

 and at the middle of the centrum. Interorbital septum always single. 

 Myodome large in front, closed abruptly behind, or open to the exterior 

 posteriorly onW through a pore. Basisphenoid with a descending 

 process. Head usually with conspicuous mucous cavities. A sub- 

 orbital shelf present on the suborbital ring. Maxillary with a large 



Fig. 2.— Occipital condyle of hoplostethas 

 japonicus. ho, basioccipital; co, exoccipi- 



TAL. 



Fig. 3.— Occipital condyle of a typical 



PERCOID FISH, ho, BASIOCCIPITAL; eo, EX- 

 OCCIPITAL. 



supplemental bone. Nasals usually very large. Actinosts placed 

 high; at least three of them on the hypercoracoid. Inner edge of 

 pelvic bones, when thoracic, elevated and united; the opposite sides 

 arching away from each other and meeting or nearly meeting below, 

 inclosing a chamber between them; the bones usually deep, sharp, and 

 compressed at the anterior end. Superior pharyngeals, 2 or 3. Ven- 

 tral soft rays usually more than 5 (reduced in number in Monocentris). 

 A pneumatic duct connecting the air bhidder with the esophagus said 

 to be present in some of the families. Vertebrw 24 to 30. Anal long 

 or moderately long. 



ff Typically in the spiny-rayed fishes, the basioccipital forms a concave condyle, 

 ■with a deep pit directly at its middle. The exoccipitals are separate, or narrowly 

 connected, and present flat obUqiie zygapophyses for the atlas, which has a deep pit 

 clirectlv at the middle of the centrum. 



