la lb 



Plate I. 

 Leptocephalus grassii, sp. nov. = Anguilla chrysypa. Figs. 1, la, lb. 



This plate shows the larva of the common eel of America. Figs, la and lb are en- 

 larged from Fig. 1 to show the detail of the head and tail. 



One specimen 47 mm. long, Albatross station 2103. One 49 mm. long, Albatross, lat. 

 38° 25' N., 72° 40' W. 



This species is distinguished by its broad well-developed vertical fins, deep and robust 

 body and absence of all pigment. Body lanceolate, sharp at both ends, deepest in the 

 middle; segments 65 +40 and 68 +40. 



This species very closely resembles Leptocephalus breviceps, which Grassi has sliown to 

 be the young of the European eel. The segments of the European eel are given as 116. 

 The vertebrae of seven young eels taken at Woods Hole during the summer of 1900 range 

 from 106 to 110, as follows: 35+71, 35+72, 36+71, 36+71, 36+73, 36+74, 42+65. 

 This number agrees with the number of segments in L. grassii. 



The close similarity of this species to Leptocephalus breviceps, the absence of color ^ 

 the structure of the caudal, and the difference of this species from breviceps in just that 

 character, viz. number of vertebrae, in which the American eel differs from the European 

 eel, make it quite certain that the present species is the larva of the American eel. 



