84 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
DESCRIPTIONS OF SPECIES. 
Leptocephalus grassii, sp. nov. = Anguilla chrysypa. Figs. 1, la, 16. 
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 at the middle; its depth 5.66 
in the length; dorsal beginning about 8 segments in front of anus, its rays becoming gradually longer 
to the caudal, whose rays are about 1 m. long; anal similar to the dorsal; pectoral well developed; 
head sharply conical, upper and lower profile equally slanting; eye large, 1.33 in snout, 4 in head; no 
pigment cells; segments 65 + 40 and 68 + 40. 
This species very closely resembles Leptocephalus breviceps, which Grassi has shown 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. 
1 . 
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. 
We take pleasure in associating the name of Professor Grassi with the larva of the American eel. 
Leptocephalus diptychus E. & Iv. Figs. 2, 2a, 2b, 2c, 2d, 2e. 
Leptocephalus diptychus, Eigenmann & Kennedy, Science, xii, p. 401. 1900. 
Type, one specimen 38 mm. long, Albatross station 2566; surface, evening. Cotype, one specimen 
51 mm. long, Albatross, New Providence; surface, electric light. 
This species differs from all other species of Leptocephalus in the presence of eight large chromato- 
phores, one in the alimentary canal a short distance in front of the anus, and seven along the middle 
line of the body, three of which are on the left side and four are on the right. Those of opposite sides 
alternate with each other, so that they appear in the translucent fish as a series of seven spots placed 
at more or less regular intervals along the side. Each one of the spots of the side consists of a large 
