272 PROCEEDINGS OF THE ACADEMY OP 



membrane deeply and acutely emarginated beneath, and with a very narrow 

 free border behind. Branchiostegal rays seven on each side. 



Dorsal fins two and entirely separated. The first with from five to nine 

 spines ; the second quite remote from the first and short, with most of its rays 

 branched. Anal fin short or oblong. Caudal fin emarginated or forked. Pec- 

 toral fins inserted low on the humeral cincture, and normally developed ; 

 its angles are obtuse. Beneath and in front are many (3 14) free articulated 

 filaments. Ventral fins thoracic and under the spinous dorsal ; each has a 

 spine and five branched rays, the first or second of which is longest. 



The muciferous excavations and channels of the bones of the head are well 

 developed. 



The vertebral column is composed of about twenty-four or five vertebrae, 

 nine or ten of which bear ribs. 



The stomach is ccecal ; the pyloric cceca are present generally in moderate 

 number, rarely numerous. 



The air bladder is very variable in form, structure and development, and is 

 sometimes absent. Its modifications do not appear to be even coincident 

 with generic characters. 



The nearest allies of this family appear to be the Scifenoids. This affinity 

 is indicated by the presence in both of the muciferous excavations of the skull, 

 the extent of the squamation and the obliquity of the rows of scales, the weak- 

 ness of the dorsal and anal spines, &c. The number of vertebra? and the char- 

 acter of the intestinal canal are also nearly similar to those of the Scisenoids. 

 The most distinctive characters of the present family have been indicated in 

 the preliminary remarks. 



On the other hand, they resemble the Mugiloids by the interval between the 

 dorsal fins, and even in some degrees by the form, squamation and position of 

 the ventral fins. 



The following analytical table indicates the most distinctive features of 

 each genus. 



Anal twice as long as second dorsal. Preoperculum entire, Polynemi. 

 Palatine and pterygoid teeth. No vomerine teeth. Pec- 

 toral filaments 5, 1. Polynemus. 

 Second dorsal and anal fin3 equal. Preoperculum serrated, Tkichidiontes. 

 Palatine, pterygoid and ( Pectoral filaments 3 8, 2. Trichidion. 



vomerine teeth. ) Pectoral filaments about 14, 3. Polistonemus. 



Palatine teeth. No vomer- > pectQral filamentg 10 _ n 4- Galeoides . 

 ine or pterygoid teeth. ) ' 



Group POLYNEMI Gill. 



Pinna analis pinna dorsali longior, antice infra'pinnam dorsalem. Preoper- 

 culum inerme. 



Anal fin longer than the second, and with its anterior portion beneath it. 

 Preoperculum entire and not dentated. 



POLYNEMUS Gronovius. 



Polynemus Gronovius, Museum Ichthyologicum, p. 31, 1754. 



Pentanemus Artedi, in Seba's Locupletissimi Rerum Naturalium Thesauri ac- 



curata descriptio, &c, torn. iii. p. 74, 1758. 

 Pentanemus Giinther, Catalogue of the Atfanthopterygian Fishes, vol. ii. p. 



330, 186061. 

 Pinna analis pinna dorsali duplo longior. Dentes velutini ossibus maxil- 

 laribus superiori inferiorique, palatinis et pterygoideis. 



Body oblong and moderately compressed, covered with moderate scales. 



[Sept. 



