. The anatomy, physiology, morphology and development of the blow-fly (Calliphora erythrocephala) A study in the comparative anatomy and morphology of insects; with plates and illustrations executed directly from the drawings of the author;. Blowflies. THE EXO-SKELETON OF THE PROBOSCIS. 135 The Clypeus (Figs. 23,5 c, and 25, b} forms the external dorsal portion of the fulcrum, or cephalo-pharyngeal skeleton. This supports the haustellum at its distal extremity. The Palpigerous Scales and Palpi.—On each side of the rostrum, near its apex, there is a convex scale (PI. VI., ps), which sup- ports


. The anatomy, physiology, morphology and development of the blow-fly (Calliphora erythrocephala) A study in the comparative anatomy and morphology of insects; with plates and illustrations executed directly from the drawings of the author;. Blowflies. THE EXO-SKELETON OF THE PROBOSCIS. 135 The Clypeus (Figs. 23,5 c, and 25, b} forms the external dorsal portion of the fulcrum, or cephalo-pharyngeal skeleton. This supports the haustellum at its distal extremity. The Palpigerous Scales and Palpi.—On each side of the rostrum, near its apex, there is a convex scale (PI. VI., ps), which sup- ports a single-jointed clavate palpus—the maxillary palpus—at its inner proximal angle. These scales are united in many of the Diptera by a curved plate of chitin, which embraces the posterior surface of the rostrum. Sesamoid Sclerites.—I apply this term to two small nodulated fusiform rods of chitin close to the apex of the rostrum on its. FIG. 27.—A portion of the Proboscis of the Blow-fly, showing the relations of the prelabrum with the theca ligula and pharynx : ap, apodeme of the labrum ; ///, the pharynx ; hy, hyoid sclerite ; pp/i, prepharyngeal tube; ;• r, part of the rostrum ; ///, the prelabrum ; lig, the ligula ; // // h, the haustellum ; ss, sesamoid sclerite ; th s, thyroid sclerite ; in in, muscles ; /;-, trachea ; /</, lingual, and scf, salivary ducts ; si', salivary valve. ventral aspect. They give insertion to the long retractor muscles of the rostrum (Fig. 27, ss). The Haustellum, or middle joint of the proboscis, consists of two valves, a large ventral or posterior valve, which I shall term the theca, and a narrow styliform dorsal or anterior valve, the prelabrum. The prelabrum lies in a groove on the anterior face of the theca, the edges of which overlap it. The theca ends distally in the great two-lobed oral disc, or sucker. The Oral Sucker is a fleshy oval disc, deeply cleft at its anterior. Please note that these images are extracted from scanned


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Keywords: ., bookcentury1800, bookcollectionbiod, bookdecade1890, bookyear1890