ATHERINID.K. 391 



We commence the series of families which more or less approach 

 the Malacopterygians mth the Atheriniche and Miu/iUdce ; they are 

 true Acanthopterygians with regard to the structiu-e of the fins, but 

 theii' ventrals have an abdominal position. The structm-e of their 

 skeleton affords an excellent character whereby to separate these two 

 groups from each other. 



Fam. 37. ATHERINID^. 



Body more or less elongate, subcylindiical, covered with scales of 

 moderate size ; lateral line indistinct. Cleft of the mouth of moderate 

 ividtli, with the dentition feeble. Eye lateral, well developed. Gill- 

 opening -^dde ; four gills; pseudobranchise; five or six branchiostegals. 

 Two dorsal fins ; the spines of the first feeble ; the second of moderate 

 length ; anal like the soft dorsal, or rather longer. Ventral Jins ab- 

 dominal, with one spine and five rays. Vertebrce very numerous in 

 the caudal and abdominal portions. 



Carnivorous fishes inhabiting the seas of the temperate and tropical 

 regions ; several species enteiing or living in fi'esh water. 



Synopsis of the Oenera. 



First Group : Atherinina. Teeth very small ; scales cycloid. The 

 first dorsal entii-ely separated from the second. An air-bladder. 

 Pyloric appendages none. 



Snout more or less obtuse, witli the cleft of the mouth 

 straight, oblique, extending to or beyond the 

 anterior margin of the eye 1. Atuerina, p. 392. 



Snout more or less produced, with the cleft of the 

 [ mouth generally not extending to the orbit ; the 



|[ lateral margins of the upper jaw are curved ... 2. Atherinichtiiys,p.402. 



Second Group : Tetragonitriiia. Teeth not very small, compressed ; 

 scales keeled and striated. The fii-st dorsal continued on to the 

 second. Air-bladder none. Pyloric appendages numerous. 



Only one genus 3. Tetragonurus, p. 407. 



First Group. ATHERININA. 



Teeth very small ; scales cycloid. The first dorsal entirely 

 separated from the second. An air-bladder. Pyloric appendages 

 none. 



