1874.] 343 • [Putnam. 



and the ridge of the preoperculum. Head one-seventh of the total 

 length of the fish. Dorsal and anal not margined with black. Gill- 

 rakers four. Air-bladder pear-shaped, with a posterior foramen. 



Mediterranean. 



Agassiz Collection. . No. 4327. Nice, Prof. C. Gegenbaur. Re- 

 ceived December, 1864. (One specimen. 5^ inches.) 



O. Vasalli Risso. 



Inner barbel very nearly as long as the outer. Outer barbel fully 

 equal to the head in length. Maxillary reaching considerably beyond 

 the posterior margin of the eye. Length of the eye equal to about 

 two-thirds of the space between its posterior margin and the ridge 

 of the preoperculum. Head slightly more than one-seventh of the 

 total length of the fish. Dorsal and anal not margined with black. 

 Gill-rakers four. Air-bladder globular, with a posterior foramen. 



Mediterranean. 



Agassiz Collection. No. 4329. Mediterranean. (One specimen. 

 7 inches. ) 



Agassiz Collection. No. 4328. Nice, Prof. C. Gegenbaur. Re- 

 ceived December, 1864. (One specimen. 6^ inches.) 



FIERASFER. 



For several years I have had in my possession eight specimens of 

 the interesting genus of Fierasfer, which were given by Prof. Verrill 

 from a number belonging to the Yale Museum, and collected at 

 Panama by Mr. Bradley, in 1866. They were all obtained alive 

 from pearl oysters, and fully prove the parasitical habits for which 

 this genus of fishes is noted. 1 These specimens show so great a 

 variation in their dentition and relative length of the head to the 

 body, as to convince me that some of the species now acknowledged 

 will prove to be unworthy of specific rank. On comparing these 

 Panama specimens with several from the Atlantic coasts, I could not 

 find any character by which they could be separated, and I am forced 

 to admit that our North American species, now for the first time re- 

 corded, is the same on both sides of the continent, making one more, 

 instance of the occurrence of the same species on the Atlantic and 

 Pacific waters of the central portion of America. 



1 In the Museum of Comparative Zoology there is one valve of a pearl oyster 

 from Panama, in which a specimen of Fierasfer dubius is beautifully enclosed in a 

 pearly covering deposited upon it by the oyster. 



