86 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Details of the distribution of spots on the two sides of L. diptychus. 
Younger specimen. 
Older specimen. 
No. of seg- 
ments between 
centers of suc- 
cessive spots. 
Serial number of proto- 
vertebrae over which 
a spot extends. 
(R=right side; L=lel't.) 
No. of seg- 
ments between 
centers of suc- 
cessive spots. 
Serial number of -proto- 
vertebrae over which 
a spot extends. 
(R=right side; L=left.) 
12 
f 15,16,17 R 
| 27, 28, 29 R 
12 
f 12, 13, 14 R. 
13 
12 
1 24, 25, 26 L. 
11 
j 40,41,42 L 
} 51,52,53 R 
12 
| 36, 37, 38 R. 
| 48, 49, 50 L. 
11 
1U-. 
14 
1 62, 68, 64, 65 L 
13 
| 58, 59, 60 R. 
| 76, 77, 78 R 
17 
J 71,72,73 L. 
15 
{ 91, 92, 98 L 
1 87, 88, 89, 90 R. 
Leptocephalus rex, sp. nov. Figs. 3, 3a, 3/). 
One specimen, 87 mm. long, Albatross, San Salvador, 1886. One 105 mm. long, Albatross, New 
Providence. The first specimen may represent a later phase of the species' called amphioxus, 
The head has taken on its adult form, the snout is rounded, the lower jaw is shorter than the 
upper, and the larval teeth have dropped out. The body is not as compressed as in true larval forms. 
The tail is long and pointed. The greatest depth is 11.5 in the length. The head is nearly 13 in the 
length. The dorsal begins a few segments in front of anus. The caudal is rounded, continuous 
with the high dorsal and anal. A series of color cells along base of anal and caudal rays; a few 
cells in deeper parts of tip of tail; no color elsewhere about body or head; segments 59 + 60. 
The second specimen differs from the one above described in having a series of spots along the 
base of the dorsal as well as the anal, and in having 123 segments. The difference in color may be 
due to difference in age. This specimen is much shriveled by alcohol. 
Leptocephalus amphioxus, sp. nov. Figs. 4, 4a, 4b. 
Type, one specimen, 65 mm. long, Albatross, lat. 38° 25' N., long. 72° 40' W. 
This species is evidently very closely related to Leptocephalus immaculatus Stromman , from which 
it differs in the more pointed snout and tail and the presence of a series of chromatophores along the 
middle of the side. Body tapering nearly equally from both ends to the middle; depth about 9.5 in 
the length; head depressed in front of the ejms, snout pointed, jaws equal; eye 1.66 in snout, 4.4 in 
head; nostrils near together; head 14.5 in the length; pectorals well developed; alimentary canal 
extending to near the tip of the tail; caudal well developed, not separated from the dorsal and anal: 
