664 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iis 



proportions have been extracted from the original descriptions or from 

 the illustrations of the types of the nominal species /. africanus, I. 

 bideni, I. cepedii, I. dekayi, I. glaucus, I. gomphodon, I. guentheri, I. 

 huidobrii, and /. tigris. Comparable data could not be obtained 

 from the descriptions of /. mako, I. oxyrinchus, and /. spallanzani for 

 a variety of reasons: either no measurements or proportions were 

 given, or no indication of the size of the specimen concerned was in- 

 cluded, or illustrations were poor or lacking. The rehability of the 

 data from some of the original descriptions is discussed on page 666 

 and elsewhere in this paper. 



Seventeen of the specimens for which there are full data have been 

 examined and measured by me. These include: one from the western 

 North Atlantic; one from the eastern North Atlantic; two from Japan; 

 three from California; seven from New Zealand; one from South 

 Africa; and two from the Indian or Pacific Oceans (exact locality 

 uncertain). Measurements were made in the manner outlined by 

 Bigelow and Schroeder (1948, p. 61). 



Data from 13 specimens taken in the central Pacific during 1952 

 through 1955 by the program of Pacific Oceanic Fishery Investigations 

 of the U.S. Fish and Wildlife Service were supplied by Dr. Donald W. 

 Strasburg. These were reported earlier in summarized form by 

 Strasburg (1958). J. Moreland provided measurements of a New 

 Zealand specimen, and S. Gruber supplied measurements of one from 

 New York. 



Information was obtained from recently published accounts of four 

 specimens from Madagascar (Fourmanoir, 1961), three specimens 

 from South Africa (Smith, 1953, 1957, 1958), and two specimens from 

 the western North Atlantic (Bigelow and Schroeder, 1948). 



The material included 31 males, 11 females, and 6 specimens for 

 which the sex was not recorded. No sexual dimorphism was observed 

 in proportions. In total length the specimens ranged from late 

 embryos 605 mm. long to an adult of 3,200 mm., the latter a cast of a 

 New Zealand female in the Auckland Museum. 



Many of the specimens were discarded after they had been meas- 

 ured, but some were preserved whole. The latter are listed under 

 Study Material in the accounts of the two species given here. 



My thanks are due to the many colleagues who have assisted in 

 this study by providing specimens and data. To those at the insti- 

 tutions mentioned variously in this account I would add Dr. T. Abe 

 (Tokaiku Suisan Kenkyujo, Tokyo, Japan) for his considerable con- 

 tribution in supplying three specimens of the new species of Isurus 

 described here; F. Begley of Awanui, New Zealand, for assistance in 

 obtaining specimens of New Zealand makos; Dr. L. R. Richardson 

 (formerly of Victoria University of Wellington, New Zealand) for his 



