1SG0.] The Cartilaginous Fishes of Lower Bengal. 35 



latitude. The Punjab Proper tinted pink having been completed by 

 the Revenue Survey operations, the upper portion of the Derajat alone 

 remaining. 



The above information is chiefly taken from the reports of Colonel 

 Waugh, Surveyor General of India and Captain Montgomerie, I am 

 also indebted for assistance to Mr. J. 0. N. James, Chief Draftsman 

 of the Surveyor General's Office, who has for some years been 

 employed in the survey of the adjoining districts. 



The Cartilaginous Wishes of Lower Bengal. — By Edward Blytb:. 



The following does not profess to be a complete catalogue of the 

 cartilaginous fishes that inhabit the embouchure of the Ganges, but 

 merely of those which I have personally obtained in the fresh state, 

 chiefly in the Calcutta fish-bazars ; and having lately had occasion to 

 look them over, and paid some attention to the group, it may be 

 useful to give an enumeration of the species observed, especially as 

 in the genus Trygon it appears that several permanently distinct 

 races or species have been confounded under Tr. uaenak, (Forskal). 



The cartilaginous fishes which I have obtained in Calcutta are as 

 follow : — 



1. Stegostoma fasciatum, Milder and Henle : uniformly spotted 

 variety, figured and described as St. carinatum in J. A. 8. XVI, 725. 

 One specimen only, procured at the Sandheads. Another, like it, is in 

 the museum of the Calcutta Medical College. 



2. Sqttaltjs (Scoliodon) xaticaudus, M. and H. A small 

 species, occasionally brought to the bazar. I have not seen it more 

 than l-§ ft. in length. 



3. Sq. (Cakcharintts) Milberti, (? Val.). One specimen 

 obtained, 2\ ft. long. A skull from the Bay, of an individual probably 

 about 7 ft. long, has the largest upper teeth measuring | in. and 

 upwards along their lateral margins : other teeth, of apparently the 

 same species, from the Indian Ocean, have a lateral margin of 1-f in., 

 and extreme breadth at base of If in. ;* they more nearly resemble the 



* Even these are small, however, in comparison with the huge fossil teeth of 

 the Caechaeias megalodon and others figured by Agassiz, and those by Dr. 

 Gibbes in the ' Journal of tho Academy of Natural Sciences of Philadelphia,' 

 for July, 1848. 



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