7. Before I dismiss the present subject, I must beg leave to take notice of the Parthian character on the field of my medal, which is not very unlike the Chaldee[114] or Palmyrene _Aleph_, tho’ of something a more complex form. Should this be allowed, that character may be considered as the initial letter of ARSACIA, the name of a city subject to the Parthians, placed by [115]Ptolemy in Media; where, according to [116]Dr. Vaillant, many of the Parthian medals were coined. That city is however believed by some to have been seated on the spot occupied at this time by Casbin, or rather Kazwîn[117], one of the principal towns of the Belâd Al Jebâl, or mountainous part of the Persian Irâk; for a particular account of which place, the curious may have recourse to Golius, and the eastern geographers. As I have already far exceeded the limits proposed to myself, when I began this letter, I shall not now touch upon any other observations relative to the medal before me, which is the only one I have hitherto met with carrying a Greek and a Parthian legend upon it; but only assure you that I am, with the most perfect regard, +SIR,+ Your most obliged and most obedient Servant, John Swinton. Christ-Church Oxon. Nov 29th, 1756. XXIII. _An Account of a Red Coral from the_ East-Indies, _of a very singular Kind: In a letter from Mr._ John Ellis, _F.R.S. to Mr._ Peter Collinson, _F.R.S._ [Read Mar. 24, 1757.] Dear Sir, I Promised you, in my letter of the 7th of February 1754, published in our Transactions, Vol. xlviii. p. 507. that I would, when I had an opportunity, endeavour to illustrate the tubular structure of the common red coral of the Mediterranean sea, and of some of the keratophyta; which two kinds, tho’ evidently of as different natures as stone and horn, yet are, from late observation, found to be fashioned, or raised up into those beautiful forms, by animals of the same class. This I shall attempt to do, by comparing them with bodies of a similar kind, but of a less compact texture: for which reason I formerly referred you, in the above-mentioned letter, to a figure, which I have given of the herring-bone-coralline with its animals alive in it, _Phil. Trans._ Vol. xlviii. TAB. XVII. _Fig._ E, F, G, to shew you the nature of the tubular structure of the keratophyta. [Illustration: _Philos. Trans. Vol. L._ TAB. III. _p. 189_. _J. Mynde_ A. _A piece of pithy knobbit and Coral from the Spice Islands in the East Indies which appears to be form’d by animals of the Polype kind, contrary to the receiv’d opinion of these bodies being vegetables; the vermicular tubes, of which it is compos’d, being no more than the cases or coverings of the bodies of these Insects._ B. _The radiated holes on the yellow mealy surface, through which these insects extend their arms or claws, as in the common red coral._