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Show 20 PROF, D'ARCY W. THOMPSON ON T H E [Jan. 17, anterior process much larger and blunter, the whole body of the bone more expanded, and the glenoid surface more elongate and less curved. The pterygoid condyle is independent, and set about halfway between the main condyle and the base of the anterior process. The quadrato-jugal cup looks nearly forwards, and is set on a powerful ridge of bone that forms a sharp free edge as we look at it from the hinder or outer sides. Immediately below the quadrato-jugal cup, on the underside of the prominent ridge, is an articular facet which plays on a corresponding surface on the edge of the mandible. The inner head of the quadrate bone is comparatively large and imperfectly separated from the outer one. The descending processes on the hinder border of the maxilla? are large. The usual mandibular fenestra is obsolete, but a small one is present (represented in a good many other forms by a small foramen) apparently between the articular and splenial elements. I have not seen a complete hyoid, and can only say that the para-byals are uncommonly large and point upwards. The skull of Stringops represented in fig. 9 is that of a young or half-grown individual, in which the orbit is still incomplete. The circumstance is natural enough, but it may serve to remind us that the completeness or incompleteness of the orbit is not, after all, a very deep-seated morphological difference; it is merely a case of greater or less extension of ossification in a ligamentous connection that is already there. Family LORIID^E. Dr. Mivart has lately given us a copious description of the skeleton of Lorius flavopcdliatus. M y account shall deal only with the points that seem to me of chief importance. I have studied four forms, Eos riciniata, Lorius domicella (fig. 11), Trichoglossus omatus, and Glossopsittaeus, sp.; these are all so similar in their main features that their descriptions may be incorporated together. Fig. 11. Lorius domicella (slightly enlarged). The postfrontal process is in all of them small, largest in Ei and least in Lorius. It is in the form of a nearly vertical rid/ |