84 PROCEEDINGS OF THE ACADEMY OP 



tinct genera, which are almost entirely characterized by the different combina^ 

 tions, of teetli on the jaws and in the mouth, or the entire absence of them. 

 There is no essential difference in the form of those teeth, and from their rela- 

 tive positions alone are the genera distinguished. We find in the subfamily 

 almost every variety of dentition ; almost all possible combinations from that 

 exhibited by the genus RogeniJ, of which the famous white bait of the English, 

 is the type, to the genus of the Shads, in which there are no teeth in any part 

 of the mouth. In Rogenia, we find teeth, more or less developed, on every bone 

 that enters into the composition of the mouth, as well as on the tongue. There 

 are vomerine, palatine, pterygoid and lingual teeth, and there are also less 

 developed intermaxillary, supramaxillary and mandibular ones. In Clupea or 

 the herrings, and in Clupeoides of Bleeker, and llarengula of Valenciennes, the 

 dentition is almost as full ; perhaps more perfect in the last, if we regard the 

 size or development of the teeth. There is in each of those genera an absence 

 of teeth on one set of the bones which enter into the composition of the mouth : 

 ali the others are provided with teeth as in Rogenia, bat stronger on the jaws. 

 In Ilarengula, the deficiency is of vomerine teeth ; in Clupeoides, of maxillary,* 

 and in the herrings, the pterygoid bones are destitute. In the last group the 

 palatine bones have also only a few isolated ones on the outside, and these 

 being readily deciduous, may be easily overlooked. From the herrings, we 

 pass by Kowala, Spratelloides and Sardinella of Valenciennes, and our genera 

 Alausella and Pomolobus to Spratella, in which there are teeth only on the 

 palatines and tongue; Meletta, in which the tongue alone is furnished, and 

 finally to Alausa of Valenciennes, and Brevoortia of Gill, in which all the bones, 

 as well as the tongue, are edentulous. Notwithstanding this variation of den- 

 tition, so uniform is the shape of the body ; so little modification is there of 

 any other part or member, that we might, perhaps with propriety, if we did 

 not look to the dentition, unite them all in one great genus. The only very 

 sensible variation from the type as exhibited in the herring, is that which has 

 furnished us with the genus Brevoortia. This genus, established on the well 

 known and very abundant " Morsebunker" or " menhaden" of our eastern coast, 

 is distinguished from almost all of its associates, by the large head, and the 

 more backward position of the dorsal fin, which is situated over the interval 

 between the ventral fins and the anal. These variations, in connection with the 

 ciliated or deeply pectinated posterior margins of the scales, have appeared to 

 us to be of generic importance. On that genus we have bestowed the name of 

 Brevoortia, in honor of Mr. J. Carson Brevoort, the well known ichthyologist of 

 New York. 



In the subfamily of the Clupeince, we include both Pellona of Valenciennes, 

 and Pristigaster of Cuvier, in a distinct group ; these genera are distinguished 

 from the true herrings, by the long anal fin, and in Pellona by generally more 

 anterior position of the ventrals ; the dorsal is usually situated nearer to 

 the former than to the latter. A9 there is no gradation between the long anal 

 of the Pellona and Pristigasters to the short one of the true herrings, and as the 

 difference of the length gives a peculiar facies to each group, the section so 

 distinguished appears to be natural. For the present at least, we may retain 

 Pellona and Pristigaster together, notwithstanding the want of ventral fias in 

 the latter. For the group thus formed we may employ the name of Pellona. 



In retaining Valenciennes' name of Pellona for the group which he so designa- 

 ted, we are well aware that he had been anticipated by both Swainson and 

 Gray, or rather Richardson. The former naturalise has characterized, as well 

 at least as was customary with him in ichthyology, the genus to which he gave 

 the name of Platggaster. That name we are prevented from employing, as it 

 had been previously applied by Latreille to a valid genus of Hymenopterous in- 



"There are at least none mentioned as being present in the supramaxillary bones, by 

 Bleeker, to whom we are indebted for our knowledge of the genus. 



[Feb. 



