SIX-f:iT,T,ET) SIIAllK. 23 



thus shewing a near correspondence with a like structure in 

 the genus Pristiurus. The texture of the skin is rough when 

 felt against the grain. Colour blackish brown on the back, and 

 pectoral, dorsal, and caudal fins; reddish grey on the sides, 

 white beneath. Lateral line pale, bent suddenly down at the 

 falcate portion of the tail. Conjunctiva of the eye bluish white, 

 the pupil large and black. It was a male — the claspers small. 

 The example here described was taken with a line, at the 

 distance of about three miles from the land on the south coast 

 of Cornwall, and at the time when it was caught appeared to 

 be feeding on pilchards. In its habits it is undoubtedly a ground 

 Shark, and like the others of that class — the Nurse and Rough 

 Hounds — appears to want activity. The fisherman who caught 

 this fish informed me that it scarcely moved after it was taken 

 into the boat. Risso says that in the Mediterranean it keeps 

 in very deep "water, but in some parts is not uncommon; but 

 Swainson never met with it during six years in which he 

 resided in Sicily. It also appears to have been unknown to 

 the older naturalists, and I have sought for it in vain in the 

 works of Rondcletius, Gesner, Willoughby and Ray, Jonston 

 and Ruysch, who may be judged ,to represent the ichthyo- 

 logical knowledge of their day. It was not known to Artedi, 

 nor to Linnceus so lately as at the j)ublication of the tenth 

 edition of his system; but is recognised in Turton's translation 

 of Gmelin's edition of that work, under the scarcely appropriate 

 name of Squalus griseus. It is there represented as growing 

 to the length of tAvo feet and half; but although this differs 

 so little from the size of the Cornish specimen, it is clear, 

 from the additional teeth specified by Turton, that the latter 

 miist have been a younger individual. An example, the first 

 and only other that has been taken in Britain, was caught 

 with a line ofi" Ventnor, in the Isle of Wight, and measured 

 little less than eleven feet in length; and Risso describes the 

 fish in terms which can signify nothing less than these full 

 proportions. In the specimen referred to by Turton there was 

 only one row of teeth in the upper jaw, but there were many 

 rows in the lower; from which we may judge that it is about 

 this period of its growth that the evolution of dentition 

 beo-ins to show itself, and first in the lower jaw. Risso 

 assio-ns three rows of triangular sharp-pointed teeth to the 



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