(Ortalis), constitute the larger genus among the Curassows, numbering twenty or more species and subspecies. The sexes are similar in appearance, the colors being plain olive-brownish or olive-grayish above, darker on the tail, and chestnut-rufous, light brownish, or whitish below. The top of the head is feathered and without the casque or helmet characteristic of certain of the other Curassows, and there is a band of these feathers down the middle of the otherwise naked throat. We may mention briefly the Chachalaca (O. Vetula maccalli), the only form reaching the United States. Of the habits of this species in southern Texas the late Dr. J. C. Merrill wrote as follows : ” The ` Chachalac,’ as the present species is called on the lower Rio Grande, is one of the most characteristic birds of that region. Rarely seen any distance from the woods or dense chaparral, they are abundant in those places, and their hoarse cries are the first thing heard by the traveler on awakening in the morning. During the day, unless rainy or cloudy, the birds are rarely seen or heard, but shortly before sunrise and sunset they mount the topmost branches of a dead tree, and make the woods ring with their discordant notes. Contrary to almost every description of their cry which I have seen, it consists of three syllables, though occasionally a fourth is added. When the bird begins to cry, the nearest bird joins in at the second note, and in this way the fourth syllable is made; but they keep such good time that it is often very difficult to satisfy oneself that this is the fact. I cannot say certainly whether the female utters this cry as well as the male, but there is a well-marked anatomical distinction in the sexes in regard to the development of the trachea. In the male this passes down the outside of the pectoral muscles, beneath the skin, to within one inch of the end of the sternum; it then doubles on itself and passes up, still on the right side of the keel, to descend within the thorax in the usual manner. This duplicature is wanting in the female . . . Easily domesticated, they become troublesomely familiar and decided nuisances when kept about the house.” The nests in this vicinity were placed in the dense mesquite bushes, especially where the limbs had been cut away, and in the cluster of branches thus left there usually accumulated a mass of leaves and twigs within which the nest was rudely shaped. The eggs number from three to five. Similar to the Guans are the Penelopes (Penelope), but distinguished among other things by having the chin and throat usually naked and provided with a central wattle, and a large, naked space around the eye. Their habits are similar to those of the other members of the group.