In Vol. XXV., p. 253, I gave some account of the dimorphism ofP. Bairdii, mainly from the observations and experiments of Mr. David Bruce. From what he had seen at Glenwood Springs, Coloradom he had satisfied himself that not onlyBairdiiandOregoniawere one species, but thatP. Hollandii, Edw., formed part of the same. Though the two first named differ in facies more decidedly that doTurnusandRutulus, andRutulusand eitherEurymedonorDaunus.Hollandiilooks on the upper side likeBairdii, but beneath,

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... while in general likeBairdii, the yellow spots are larger, making the surface much gayer.