222 



SIXTH REPORT — 1836. 



Carcharias punctafus, Mitch. N. York. 

 Selache maximus, Id. A'^ York. Mass. 



„ Amcricanus. Id. N. York. 

 Somniosus brevipinna, Le Sueur, Ac, Sc. 



Ph. Mass. 

 Zygsena malleus, Valen. Mass. N. York. 



„ tiburo, Penn. Sm. Mass. 

 Squatina Dumerilii, Le Sueur, I. c. 1, 



10. 

 Pristis antiquorum, Cuv. U. S. Penn. 



Fam. Raiide^. 



Torpedo sp. — Benn. Monterey. 



„ — ? Mitch. N. York. 

 Raia Sayii, Le Sueur, N. Jersey. 



„ Desmarestii, Id. Florida. 



„ eglanteria. Id. Carolina. 



„ Chantenay, Id. Pennsylv. 



„ fiillonica, Fabr. Greenland. 



„ ocellafa, Mitch. N. York. 



„ diaphana, Id. Do. 



„ ceniroura, Id. Do. 



„ bonasus, Id. N. York. 



Raia batis, Smith. Massach. 



„ clavata, Id. Do. 

 Trygon sabinum, Cuv. Florida. 



„ micrura, Cuv. N. Jersey. Le 



SUEUR. 



Myliobatis Fremenvillii, Le Sueur. Rhode 

 Id. 



„ quadrOoba, Cuv. N. Jersey. Le 

 Sueur. 



„ narinari, Marcgr. San Bias. 

 Benn. 

 Cephaloptera mobular, Duh. 17. Dela- 

 ware. Le Sueur. 



„ vampirus, Mitch., Penn. N. 

 York. 



Fam. Cyclostomata. 



Petromyzon tridentatus, F. B. A. 3, 293. 

 Columb. R. 

 „ fluvialis, Id. & Mitch, N. York, 

 Mack. R. 

 Petromyzon marimts, Mitch. N. York, 

 Mass. 

 „ niffer, Raf. Ohio. 



Selachiidece. — The European seas nourish about thirty mem- 

 bers of this family, belonging to the genera scy Ilium, carcharias, 

 lamna, galeus, mustelus, notidanus, selache, spinas, centrina, 

 scymmis, zygcena, squatina, and ])ristis. The sharks of the 

 American seas have been very imperfectly investigated ; but 

 since the food provided for them is much the same as on the 

 east side of the Atlantic, we may expect to find them exhibiting 

 the same generic forms, and their analogy to the birds and 

 beasts of prey would also lead us to the same conclusion. 



RaiidecB. — Cuvier, in speaking of the Rays, observes that no 

 confidence whatever can be reposed on the synonymy of Artedi, 

 Linnaeus, and Bloch, since these authors have taken their spe- 

 cific characters chiefly from the number of spines, which vary 

 with the age and sex of the individual. Hence as the Linnaean 

 names have been imposed on many of the American rays, our 

 list is without doubt erroneous as well as defective. About 

 twenty species have been described as inhabitants of the Euro- 

 pean seas ; they are distributed by Cuvier into the following 

 genera ; rhinohatis, torpedo, raia, trygon, myliobates, and 

 cephaloptera. 



Cyclostomata. — Of this family, which contains the most 

 simply organised fishes, the European seas nourish only about 

 seven species belonging to the genera petro)7iyzon,gasterobran- 

 chus, ammocoetics, and amj)hioxus (Yarrell), but there is reason 

 to believe that the family is more numerous in the American 

 waters. The petromyzon tridentatus which inhabits the estu- 



