The Tres Marias, or Three Marias, off the western coast of Guadalaxara, in the kingdom of Mexico, are in a range stretching from S.E. to N.W. of about forty-five English miles in length.  The largest island is the N.W. which appeared a high double land, and above five leagues in length:  the middle island about three leagues; and the south-eastermost hardly two leagues.  There also are high lands, full of trees; and near the least island there are two or three small broken white islets, one of which was so like a ship under sail, that we gave the signal for a chase.  The S.E. end of the island is in lat. 21 deg. 10’ N. long. 105 deg. 56’ W. and the N.W. point of the N. island is in lat. 21 deg. 40’ N. long. 106 deg. 26’ W. the distance from each being about two marine leagues.  These islands have abundance of parrots of different sorts, with pigeons and other land-birds, of which we killed great numbers.  There were also many excellent hares, but much smaller than ours.  We saw likewise abundance of guanas, and some racoons, which barked and snarled at us like dogs, but were easily beaten off with sticks.  The water is more worthy of remark than any other thing we saw here, as we only found two good springs, which ran in large streams; the others being bitter and disagreeable, proceeding, as I suppose, from being impregnated by shrubs or roots growing in the water, or from some mineral.

The turtle we found here are of a different sort from any I had ever seen, though very good.  Though it is ordinarily believed that there are only three sorts of sea-turtles, yet we have seen six or seven sorts at different times, and our people have eaten of them all, except the very large whooping or loggerhead kind, which are found in great plenty in Brazil, some of them above 500 pounds weight.  We did not eat of these, because at that time our provisions were plentiful.  At the Gallapagos, both males and females were observed to come on shore only in the day time, quite different from what I had heard of them at other places; whereas all we caught here were by turning them over in the night, when the females come on shore to lay their eggs and bury them in the dry sand.  One of these whom we caught had 800 eggs in her belly, 150 of which were skinned over and ready for being extruded at once.  Some authors alledge that these eggs are six weeks in hatching, which I can hardly credit, as the sun makes the sand in which they are deposited excessively hot, and they are only covered by a very thin film or skin, instead of a shell.  In order to ascertain this point, I made some of our men ashore watch one carefully, and mark the place and time of laying her eggs.  In less than twelve hours they found the eggs addled, and in about twelve hours more they had young ones completely formed and alive.  Had we remained some time longer, I might have thoroughly satisfied myself and others, respecting the quick production of tortoises; for I am apt to credit the report of several of our men, who asserted that having found eggs in the sand, and looked for them three days afterwards in the same place, they then found nothing but films; which shews that the young ones are hatched in that time.  They assured me also that they had seen the young brood run out of the sand every day, making directly in great numbers for the sea.