128 ON THE SATJROGNATHISM OF THE PICI. [Feb. 3, 



the elbow. Seven prominent osseous papillae occur at nearly equal 

 distances apart down the shaft of the ulna. The flat, rounded 

 process from the postero-upper third of the shaft of index meta- 

 carpal is present. The slender last metacarpal extends below the 

 one of index, and its free digital joint is larger than either of the 

 other terminal phalanges. The proximal phalanx of index digit has 

 its posterior blade almost entirely aborted. There are no claws. 



31. Femur is always pneumatic, and so may be the tibio-tarsus in 

 some species. In the former the trochanter major does not rise above 

 the summit of the shaft ; the excavation on the head is very shallow. 

 Shaft nearly straight ; condyles rather small ; popliteal fossa and 

 rotular channe very shallow. Pki possess patellae. Cnemial crest 

 of tibio-tarsus elevated above summit of bone, with pro- and ecto- 

 cnemial ridges nearly or quite aborted. Condyles of this bone very 

 distinct, and intercondyloid valley very deep. Bony bridgelet 

 confines tendons in front. Fibula short and free, its lower spicula- 

 like end being held well away from shaft of tibio-tarsus by the 

 increasing height of fibular ridge on the latter bone. 



Hypotarsus of tarso- metatarsus both grooved and perforated for 

 passage of tendons. An erect process occurs on the summit of this 

 bone of the leg. Its shaft is nearly straight, and its terminal 

 trochleae are specially modified to meet the podal requirements of the 

 picine zygodactyle foot. 



Joints of pes normal, 2, 3, -1, and 5 to the first, second, third, and 

 fourth toes respectively. Fourth toe permanently reversed, and first 

 toe, together with its free metatarsal bone, may be entirely absent 

 (Picoic/es). A larger sesamoid articulates with a special trochlea 

 (intended for it) to the inner side of the fourth toe. The osseous 

 claws usually large, and the other phalangeal joints more or less 

 laterally compressed. The tendons of the leg sometimes ossify to a 

 certain degree, and minute sesamoids may occur in certain tendons 

 near the knee-joint. 



Brief Remarks on the probable position of the Pici in the System, 

 and on their Affines. 



Huxley in his '* Celeomorphse " comprehended only the Picidce 

 and lyngida, and Parker long ago said that " the ' Celeomorphae ' 

 of Huxley form a most natural and well-defined group — a group equal, 

 zoologically, to the Pigeons or the Parrots. Evidently this differ- 

 entiation has taken place through the gradual extinction, during long 

 secular periods, of coujugational tyjies more generalized than those 

 now extant." In this much the present writer agrees with the two 

 great authorities we have just quoted. 



To those at all familiar with the osteology of existing birds it must 

 be very evident that in an anatomical system, at least, the Pici hold 

 many characters in common with the Passeres, a fact that will be 

 evident when we come to treat of that group later on. It is my 

 opinion that it is to the great Passerine group that the Pici are more 



