. Bulletin of the Department of Agriculture. Agriculture; Agriculture. HORSE-FLIES AND WESTERN AGRICULTURE, 15 interiorly, very close to epicranial suture, by a fine dark-brown line. Lateral surface of head capsule with a dark fine line from middle of the main dorsal stripe to the point where tip of cardo attaches. Processes at anterior part of head capsule, and anterior tentorial arm (D), heavily chitinized, dark brown. Dorsally and laterally the head capsule is formed by fusion of the immovable labrum, the clypeus, the epistoma, the membranous bristle-bearing projection partly represent
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. HORSE-FLIES AND WESTERN AGRICULTURE, 15 interiorly, very close to epicranial suture, by a fine dark-brown line. Lateral surface of head capsule with a dark fine line from middle of the main dorsal stripe to the point where tip of cardo attaches. Processes at anterior part of head capsule, and anterior tentorial arm (D), heavily chitinized, dark brown. Dorsally and laterally the head capsule is formed by fusion of the immovable labrum, the clypeus, the epistoma, the membranous bristle-bearing projection partly representing the frons, and the epicranium; posteriorly the capsule is closed by a convexly rounded wall limiting the occipital foramen behind, and ventrally it is bridged by the large median gular plate, limiting the occipital foramen in front. Occipital foramen ventral, large. All anatomical elements of the cranium are recognized principally by those criteria by which they are characterized throughout the entire insect class, sutures being present only to a very limited extent. Labrum about one-fifth the length of entire head cap- sule, very narrow, compressed, keel shaped, with dorsal surface bent down- ward like the bill of a bird of prey, whitish, membranous, with the inside en- forced by one pair of long splinter-like chitinizations; posteriorly united with clypeus. Clypeus flat, ovate, almost circular, diameter about one-third the length of labrum'; shiny yellow, with posterior one-third somewhat darker. Epistoma (D) characterized by socket with which mandible articulates dorsally; developed as separate sclerite, forming a strong frame on each side of clypeus; anteriorly prolonged as a slender process, which projects close to and along the side of posterior half of-labrum; posteriorly flattened into a triangular plate. From the anterior margin of this latter (D), the aforementioned articulat- ing socket projects on the inside, reaching forward as far as half the length of the sle
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