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PROCEEDINGS OF THE NATIONAL MUSEUM 



Jaws of additional specimens were examined from the collections 

 of the above-mentioned institutions and from others including the 

 South African Museum (Capetown), the Institut Frangais d'Afrique 

 Noire (Goree, Senegal), the American Museum of Natural History 

 (New York), and the California Academy of Sciences (San Francisco). 



Discarded after measurement and examination: Two males, 1,050 

 mm. and 2,535 mm., and one female, 2,642 mm. from New Zealand; 

 one female, 1,920 mm., from off Cape Peninsula, South Africa. 



Diagnosis. — An Isurus mth short to moderately long pectoral fins, 

 always shorter than length of head (pectoral fin length usually less 

 than 70 percent of head length but up to 84 percent in very large 

 specimens) ; \\dth underside of snout and around mouth white in color; 

 and with first tooth on each side of symphysis in both jaws having 

 an incomplete cutting edge on its lateral margin (cutting edge ex- 

 tending only part way from tip of cusp toward base) except in very 

 large specimens, 2,500 mm. long or more, where the cutting edge 

 approaches or reaches the base. 



Figure 6. — Isurus oxyrinchus: a, Dom. Mus. (New Zealand) 3014, female, 1438 mm., New 

 Zealand. First dorsal fins showing change in shape and proportions with growth: b, Mus. 

 Comp. Zool. (Harvard) 37994, embryo, male, 605 mm., Bahamas; c, Dom. Mus. (New 

 Zealand) 2945, female, 871 mm.. New Zealand; d, specimen in fig. a above; e, male, 2535 

 mm, New Zealand; /, female, 3,200 mm., New Zealand (drawn from cast in Auckland 

 Museum). (Names in quotation marks are nominal species to which the specimens pre- 

 viously would have been referred according to their fin shapes and proportions.) 



Description. — For extensive descriptions of this species see Bige- 

 low and Schroeder (1948, p. 124) and Smith (1953, p. 977; 1957, 

 p. 94; 1958, p. 134), variously under the names /. oxyrinchus, I. 

 glaucus, and /. iigris. 



Table 2 gives the proportional dimensions of five specimens of 

 /. oxyrinchus for comparison with those of the long-finned species. 

 Vertebral counts and data for specimens of /. oxyrinchus do not show 



