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Show 156 DR. P. CHALMERS MITCHELL ON THE [May 16, quill than to the most distal secondary-quill in most Limicohe, but the position varies, and that shown in the diagram is more primitive. As evidence of their association with the secondary series, there is to be taken into account first the fact that the covert crosses the remex as in the secondary rows, not lying distal to it as in the primaries, and, secondly, that a plica (pi.), to which I have called attention in other groups (4 and 5 ), unites the carpal remex with the most distal secondary remex. Text-fig. 23. a * Wing-structure of Chionis alba. Diagram of the distal secondary quills and coverts, showing the diastata.ric arrangement. S. First secondary. P. First primary, x . Diastataxic gap. C.R. Carpal remex. C.C. Carpal covert. PI. Plica, binding carpal covert to first secondary. The condition of the wing in the Limicolfe is similar to that found in the greater number of the Columba?, but whereas in some Columbce (4) the eutaxic condition is found-or, as I have tried to show, has been attained,-it has not been attained by any of the Limicoke. In the Gruiformes, a somewhat incoherent group certainly closely related to the Charadriiformes, both conditions of the wing are present (7). G u t - p a t t e r n s i n t h e L im ic o l ^e . I have already shown (6) that the pattern of the gut in Limicohe is of considerable interest. It displays a configuration which differs from the pattern which is archecentric for all birds in a fashion similar to the divergence shown by the Gruiform birds, |