80 
PACIFIC SCIENCE, Vol V, January, 1951 
are now generally held, on the basis of 
Wright’s analyses (1940^^, b; 1942), to be 
little subject to differentiation. 
ADDENDUM 
After this manuscript was submitted for 
publication, Springer (1950: 2, 7-8) erected a 
distinct genus, Pterolamia, for the reception of 
Carcharhinus longimanus and, probably also, of 
C. insularum (Snyder), a species described 
from the Hawaiian Islands. He separated this 
nominal genus from Eulamia solely on the 
basis of the rounded tips of the dorsal and 
pectoral fins. Since the sharpness of these fins 
varies considerably and since the rounded 
tips seem to involve merely the retention of 
an embryonic feature, I am disinclined to ac- 
cept the generic separation. Some other 
species of Carcharhinus^ for example, C. falci- 
formis (Muller and Henle) as described by 
Bigelow and Schroeder (1948: 329-333, figs. 
56-57), have the pectoral scarcely more 
pointed than in C. longimanus and have the 
dorsal distinctly though less broadly rounded. 
Nor does Springer’s separation of Eulamia 
from Carcharhinus seem justified on the basis 
of the presence or absence of a middorsal 
ridge— a very tenuous distinction that de- 
pends in large part on the condition of preser- 
vation and that seems to be inconsistent, in 
some species at least. 
That Carcharhinus longimanus may be com- 
mon in the open equatorial Pacific is sug- 
gested by a picture in the recently published 
book Kon-Tiki, showing nine sharks caught 
in one day (Heyerdahl, 1950: lower figure of 
2d pi. following p. 176; accompanying text 
apparently on pp. 205-206). So far as is ob- 
vious all sharks in this picture seem referable 
to the pelagic species under discussion. This 
identification is ventured on the basis of the 
showing of certain diagnostic characters, in 
particular the broadly rounded pectoral fins, 
much longer than the head; the far-forward 
position of the nostrils on the very short, 
strongly rounded, laterally angulated snout; 
and the plain coloration. The location of the 
catch is not specified, but the context indi- 
cates that it was in the South Equatorial 
Current somewhere between Peru and the 
Tuamotu Archipelago. 
REFERENCES 
Beebe, William, and John Tee- Van. 1941. 
Eastern Pacific expeditions of the New 
York Zoological Society. XXV. Fishes 
from the tropical eastern Pacific. [From 
Cedros Island, Lower California, south to 
the Galapagos Islands and northern Peru.] 
Part 2. Sharks. Zoologica 26: 93-122, figs. 
1-34, pis. 1-2, 
Bigelow, Henry B., and William C. 
Schroeder. 1948. Fishes of the western 
North Atlantic. Sharks. Sears Found. Mar. 
Res., Mem. 1, Pt. 1, Chap. 3: 59-576, figs. 
6 - 106 . 
Fowler, Henry W. 1905. New, rare or little- 
known scombroids. No. IT Acad. Nat. 
Set. Phila., Proc. 57: 56-88, figs. 1-5, 
1944. Results of the Fifth George 
Vanderbilt Expedition (1941) (Bahamas, 
Caribbean Sea, Panama, Galapagos Archi- 
pelago and Mexican Pacific islands). The 
fishes. Acad. Nat. Sci. Phila., Monogr. 6: 
57-529, figs. 1-268, pis. 1-20. 
Gill, Theodore. 1862. Synopsis of the 
carangoids of the eastern coast of North 
America. Acad. Nat. Sci. Phila., Proc. 1862: 
430-443. 
Heyerdahl, Thor, 1950. Kon-Tiki. Across the 
Pacific by raft. 304 pp., 40 pis. Rand 
McNally & Co., Chicago. 
Jordan, David Starr, and Edwin Chapin 
Starks. 1907. Notes on fishes from the 
island of Santa Catalina, southern Cali- 
fornia. U. S. Natl. Mus., Proc. 32: 67-77, 
figs. 1-8. 
Meek, Seth E., and Samuel F. Hildebrand. 
1925. The marine fishes of Panama. Field 
Mus. Nat. Hist., Publ. 226 (ZooL Ser., 15): 
i-xix, 331-707, pis. 25-71. 
