80 Dr. Bancroft on some Animals of Jamaica. 
Art. XVIII. Remarks on some Animals sent from Jamaica. 
By E.N. Bancrorr, M.D., Corr. Mem. Z.S., &c. 
TO THE EDITOR OF THE ZOOLOGICAL JOURNAL. 
July 30th, 1829. 
Sir, 
I HAVE already written to you on the 27th inst., to acknowledge the 
receipt of your two letters, dated the 23d August last, and to acquaint 
you that the Jamaica Society had shipped on board the brig Mars, 
Hoseason, a small barrel containing the genital organs of a second Manta, 
(vide Zool, Journ. IV, 449.) alluded to in my letter of the 13th October, 
which I have since been led to suspect was a male, and not a female, as 
had then been supposed.* I was obliged to close my letter on Monday 
last, in very great haste, and omitted to inclose the drawings of the parts 
of that Manta; but I shall inclose them in this, with some sketches of my 
own, to be presently noticed. I now beg leave to acquaint you that I send 
you, for the Zoological Society, a chip box, a small flat oval keg, and a 
small phial, by the Barque Highbury, Capt. Pearce, and that these pack- 
ages contain, inter alia, the following objects of Natural History, viz. 
1. Aspecies of Procellaria (not your Thalassidroma), which is per- 
* In the letter here referred to, Dr. Bancroft states, ‘ I had been led to sup- 
pose that the Manta we sent last year was a male, and the second a female, 
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in consequence of the accounts given to me by some of our surgical practi- 
tioners here, who had taken the trouble of opening both subjects. I was, 
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however, soon after led to doubt of their knowledge of comparative anatomy, 
« and to suspect that they must have mistaken the sexes: ocherwise there would 
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be a singular deviation in the Mantas from the structure believed to be com- 
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mon throughout the Ray family, in which the males alone are furnished with 
“« a sub-cylindrical process from the side of each ventral fin next to the tail, a 
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deviation that I consider as most improbable. But, to show that the error 
“* was not originally mine, and that I was led into it, Iinclose two drawings 
of the parts in the second Manta, made by the gentlemen to whom I have 
alluded, in which is represented what they thought was the vagina. 
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