NATURAL SCIENCES OP PHILADELPHIA. 263 



The habitat of C. isodon has not been specified ; but as the specimen oa 

 which it waB founded was sent by Mr. Milbert, it was probably obtained at 

 New York. 



SCOLIODON M. and H. 



SCOLIODON TERRjE-NOVjE Gill. 



Squalus (Carcharias) terrae-novae Rich. 

 Scoliodon terra-novae Gill, Cat. 



Hab. Newfoundland and New York. 



As already indicated by Muller and Henle,(p. 189), the S. terrse.-novse of Rich- 

 ardson evidently belongs to the genus Scoliodon as now understood, and has 

 no affinity with Lumna to which it has been referred by several authors.* 



GALEOCERDO M. and H. 

 15oreogaleus Gill. 



Galeocerdo tigrinus M and H. 

 Galeus macwlatns Ram. 



To this species I refer two jaws, said to have been obtained on the eastern 

 coast, and others from the West Indies, Lower California and the Western Pa- 

 cific. The jaws are from adult fishes, and resemble in the form of the teeth 

 the G. arcticus. 



Muller and Henle distinguish two species of Galeocerdo. 



G. tigrinus with, 1, a moderate flat snout; 2, teeth 25 } coarsely serrate, and 

 the unpaired one little bent, and with an entire terminal point ; 3, elongated 

 caudal; 4, spotted body ; 5, last two branchial apertures above the pectorals ; 

 6, anal fin, with the anterior lobe little produced and rounded. 



G. arcticus with, 1, a very short snout ; 2, teeth 2.?, finely crenulated, the un- 

 paired teeth curved and crenulated throughout; 3, caudal moderate; 4, imma- 

 culate body ; 5, fifth branchial aperture only above the pectorals ; 6, anal with 

 its anterior lobe much produced and pointed. 



Placing an undue value on these differences, I formerly proposed to generi- 

 cally distinguish G. arcticus. 



To Prof. Poey I am indebted for the figure of an adult Galeocerdo, exhibiting 

 the gills aud anal fin of G. tigrinus, but the form and teeth of G. arcticus ; he 

 believe3 that his fish is only the adult form of G. tigrinus, and I am obliged to 

 agree with him in this view. Tbe body, and especially the caudal and snout, 

 became abbreviated with age, and the teeth change. The jaws seen by me 

 exhibit variations in number from 21 to 23, but none 25. Can the latter for- 



'i 5 



inula be the result of a typographical error? 



MUSTELINJE Bon. 

 MUSTELUS Cuv. 



Mustelus canis Dekay. 



Squalus canis Mitch. Trans. N. Y. i. 486. 

 Mustelus canis Dekay. 



Hab. Eastern coast. 



SPINAGOIDM Owen. 



SQUALUS Art. Raf. 



Squalus americanus Gill. 

 Squalus acanthias Mitch, (vix auct.) 



* The S. teme-novm and Lttmna punctata {Aprionodon) Galeorhinouls have been lPganJe I .<*> 

 identical and belonging to the genus Lo.mna. 



1864.] 



