Zoology.] NATURAL HISTORY OF VICTORIA. [Fishes. 



Measurements — continued. 



Measurements. ft. ins. lines. 



Length of posterior margin of ventral 



„ of claspers of male 



„ of base of 1st dorsal 



„ of anterior margin of 1st dorsal 



„ of base of 2nd dorsal 



„ of anterior margin of 2nd dorsal 



„ of base of anal 



„ of anterior margin of anal ... 

 Greatest depth of middle of caudal fin 

 Length of anterior edge of posterior terminal portion of caudal 



beyond notch 

 Length from tip of snout to anterior margin of eye 

 Diameter of eye 

 Distance between eyes 



„ from posterior edge of orbit to middle of spiracle 

 Length of spiracle 



„ from anterior gill-opening to tip of snout 



„ of largest anterior gill-opening 

 Girth in front of pectoral ... 



This most beautiful Shark is not very uncommon in Hobson's 

 Bay, three fine specimens being in the Museum collection. The 

 coloring varies in size and shape of the cloudings and spottings a 

 little ; and the number of lobes into which the skinny appendages 

 of the sides of the head and neck are divided is so irregular that the 

 two sides are often dissimilar in one individual. 



Explanation of Figures. 



Plate 43. — Fig. 1, side view of average male specimen, showing the claspers beyond the 

 ventral fins, reduced. Fig. la, head of ditto, viewed from above, to show the form and disposition 

 of the appendages and spiracles. Fig. 16, side view of mouth. Fig. lc, front view of mouth, 

 showing the number of rows of teeth in use. Fig. Id, one of the teeth, natural size, showing 

 the median lobe of the base. 







8 











8 











6 











7 











6 



6 







6 











3 



6 







3 











1 



6 







3 











7 



4 











9 







5 



6 







1 



9 







2 



9 



1 



4 



6 







2 



6 



3 



5 







Plate 43, Fig. 2. 



NOTIDANUS (HEPTANCHUS) INDICUS (Cuv.). 

 The Seven- Gllled Shark. 



[Genus NOTIDANUS (Cuv.). (Sub-kingd. Vertebrata. Class Pisces. Order Plagios- 

 tomata. Section Selachoidei. Fam. Notidanidae). 



Gen. Char. — Only one dorsal fin, nearly opposite the anal ; no pit at the root of the caudal 

 fin ; no nictitating membrane ; spiracles very small ; no labial fold ; mouth moderate ; gill- 

 openings very large ; 6 (sub-genus Hexanchus), or 7 (sub-genus Heptanchus), teeth in the upper 

 jaw, composed of usually 2 or 3 simple, narrow, pointed teeth in front, without cusps at base, 

 behind which on each side are about 6 broad, obliquely-triangular, flattened teeth, usually the 



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