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Show 172 DE. ST. GEOEGE MIVAET ON THE [Mar. 5, in that the crura of its parahyal arch where they meet are not prolonged into a symphysis. It is possible that a prolonged symphysial portion may have been broken off, but I cannot detect any trace of the fracture. The urohyal is very short, but slightly deflected ventrally towards its truncated distal end. The entoglossum is rather more prolonged compared with the basihyal. It presents all the characters already noted in Lorius and Eos. The ventral prominences of the preaxiad expansions of the two entoglossals are in contact. The hgpobrancliials were broken in the specimen examined, but seem much like those of Lorius domicella, but perhaps a little stouter. STRINGOPS HABBOPTILUS. (Fig. 6, p. 173.) The hyoid of Stringops differs altogether from those of Lorius, Eos, and Trichoglossus, and has a general resemblance to that of Psittacus erithacus. The basihyal has its anterior part much deeper and more laterally compressed than in P. erithacus, while its posterior, subquadrate part is hardly so much expanded laterally. The superior margin of the basihyal, when laterally viewed, is more concave dorsally, while its inferior margin is more convex ventrally, the bone being more bent concave upwards. There is hardly a perceptible concavity on the dorsum of the saddle's upper lip. The two halves of the posterior margin of the basihyal are each more concave and form a more marked angle with each other. The parahyal processes are longer, stronger, and while proceeding forwards and very slightly inwards, ascend much more sharply dorsad and slightly expand at their extremities. The urohyal is much as in P. erithacus, only more inclined ventrad towards its distal end. The entoglossum has a narrower median vacuity than in P. erithacus, while each anterior and posterior extremity projects more outwards, especially the two anterior extremities, so that the anterior half of each lateral margin is much more concave. The dorsal surface of the entoglossum is also very much more flattened than in P. erithacus. Thus the bony isthmus formed bv the median junction of the two inwardly projecting portions of the two entoglossals (just in front of the basihyal saddle) is quite on the dorsal surface of the entoglossum, instead of being sunk at the bottom of a strongly marked concavity-as it is in Psittacus, Lorius, Eos, and Trichoglossus. The dorsum of each entoglossal process projecting back behind the bony isthmus is also flattened, though faintly grooved antero-posteriorly. Seen ventrally, each entoglossal presents a wide shallow concavity at its laterally expanded preaxial end. Behind this is the prominence of the anterior lateral process, and behind this again is the marked concavity (looking externad as well as ventrad) of the hindermost part of each entoglossal. |