NATURAL SCIENCES OF PHILADELPHIA. 273 



H. Richardi is probably very nearly allied to, and perhaps even identical with 

 the jEsox brasiliensis L., the type of the genus Hemirhamphus of Cuvier, the 

 name Hyporhamphus should probably be suppressed. If this identification 

 then is correct, a new name should be conferred on the species with conic 

 teeth. This question, as well as that of the proper name of the genus, will 

 be hereafter discussed. 



The genus Hemirhamphus of Cuvier is not a homogeneous one, but em- 

 braces at least four distinct generic types distinguished as follows : 



A. Body with the back and abdomen parallel; lower jaw very long, uni- 



form and depressed. 



I. Caudal fin forked, and with the lower lobe longest. 



1. Teeth tricuspid above and below; bill moderate ; 



dorsal and anal pluriradiate ; pectorals moder- 

 ate ; ventrals moderate Hemirhamphus. 



2. Teeth conic above, tricuspid below; bill very 



slender ; dorsal and anal pluriradiate ; pectorals 



very long ; ventrals small Euleptorhamphus. 



II. Caudal fin convex behind. Anal fin of male with 



some thickened rays Zenarchopterus. 



B. Body subfusiform ; lower jaw acutely cuspidute Oxyporhamphus. 



The type of Hemirhamphus Cuv. is Esox brasiliensis Linn.; of Euleptorhamphus 

 Gill (I860,) E. Brevoortii; of Zenarchopterus, Hemirhamjihus dispar C. et V. (xix. 

 p. 58, pi. 558) and of Oxyporhamphus, Hemirhamphus cuspidatus (C. et V. xix., p. 

 56, pi. 55*7.) The last is only known to me through the description and figure 

 given by Valenciennes. 



On STREPOMATID.E as a name for a family of fluviatile Mollusca, usually con- 

 founded with Melania. 



BY S. S. HALDEMAN. 



In the American Journal of Science, vol. 41, 1841, in my monograph of Lep- 

 toxis, 1845, and in the Iconographic Encyc, I pointed out the necessity of dis- 

 tributing the heterogeneous Melaniae of Lamarck into two separate families, 

 according as the margin of the mantle is festooned, as in the species of the Pa- 

 cific Islands, or simple, as in the North American species. Knowing the two 

 forms to be distinct, I proposed, in accordance with the position assigned by La- 

 marck to his family M61aniens, to restrict the name Melania to the American 

 group; but as the oriental species were best known in Europe when the genus 

 was instituted in 1801, and as Deshayes (following Bruguiere, Fe"russac 180*7, and 

 Rang, Mag. de Conch., pi. 12,) described the animal of Melania, or Pirena, as 

 having a festooned mantle, (in his edition of Lamarck 8,427; 1838,) followed 

 by others, as H. and A. Adams, who give " mantle margin fringed " as a charac- 

 ter, European naturalists were averse to giving up the name for the oriental 

 group ; and as it is a matter of little scientific importance, if the families are 

 properly recognised, I now reluctantly yield it to the oriental form, and conse- 

 quently withdraw the American species from it. 



In thus giving up the name of Melania as applicable to American species, it 

 must not be forgotten that Lamarck's family of Melaniens includes the three 

 genera Melania, Melanopsis, and Pirena, and that from its position in his sys- 

 tem, and the structure of the European Melanopsides, he would not have in- 

 cluded the species (like the oriental Melania amarula, or the African Pirena 

 aurita,) with a festooned mantle, which have gradually become the representa 

 tives of" Melania," from the accidental circumstance that the mollusc was 6rst 

 described from them. The fact that Lamarck commences his series with the 



1863.] 20 



