18C8.] ON A SUPPOSED NEW GALEOCERDO. 3Gf) 



by Miiller and Henle (pi. 24), and by Prof. Owen (in his 'Odon- 

 tography,' pi. 28. fig. 9) of the northern Tope bear a general 

 resemblance to those of ]\Ir. Ilayner's specimens, yet, on careful 

 comparison, the latter are found to be more delicately crenulated 

 towards their summits. In colour the southern Tope {G. tigri- 

 nus), figured by Miiller and Ilenle in plate 23 of their work, has 

 something in common with our Shark, particularly in the form and 

 disposition of the markings ; but in the general contour, and in the 

 proportion of the fins, there is much disagreement. This is especially 

 noticeable in the tail; for whereas in G. tiffrinus the caudal fin, 

 measured from the tail-pits to its extremity, is more than a third 

 of the entire length of the fish, in Mr. Rayner's Shark this mem- 

 ber is only a little more than a fourth of the extreme length, and 

 agrees better with the tail of G. arcticus as well in proportion as in 

 form. 



The two Australian jaws collected by Mr. Rayner have been care- 

 fully compared with six entire jaws and a portion of a seventh, col- 

 lected in southern seas by different naval oflacers, who presented 

 them, at various times, to the Haslar Museum*; and they have been 

 found to agree in every particular. 



With such evidence of the apparent frequency of this Shark, 

 and of its range in southern seas, one might be led to consider it 

 identical with the known southern Tope ; but there are also distinc- 

 tive characters which we think sufiicient to aiford good presumptive 

 evidence of the existence of a marked variety, if not a distinct spe- 

 cies ; and in honour of the gentleman whose labours have furnished 

 much material and many interesting facts relating to this group of 

 fishes, we wish to bestow on it the provisional name of Galeocerdo 

 rayneri. 



Mr. Rayner's notes, taken from the recent specimen, are here 

 transcribed : — 



" Dimensions of a female ^sh taken in March 1858. 



feet. in. 



'•' Length to tail-pit 6 2 



Length of tail-fin 2 3| 



Girth , 3 8i 



" Head short, flat and inflated at the angles of the jaws ; snout 

 short and rounded ; nostril slit transversely, with a conical flap 

 attached to the inner side of the anterior border, and the external 



* 1. Large entire jaw from St. Tiiomas, Virgin Island, presented by Francis 

 Cole, Esq., E.N. 



2. Large entire jaw, locality unknown. 



3. Large entire jaw, from the west coast of Australia. 



4. Large entire jaw, fi-om near Lord Howe's Island, presented by F, M. 

 Earner, Esq., E.N. 



5. Large entire jaw, locality imlniown. 



6. Entire jaw of smaller size, locality unknown. 



7. Portion of jaw of large size, from the Pacific, presented by — Wood, Esq., 

 R.N. 



Proc. Zool. Soc— 1868, No. XXIV. 



