172 SHOULDER-GIRDLE AND BREAST-BONE. 



coracoid is not so slender as in the Toucan and Woodpecker ; and both the meso-coracoid and 

 epicoracoid regions are much more expanded : the former has coalesced with the head of the 

 bone, forming a perfect canal for the tendon of the middle pectoral muscle, as in some of the 

 Synclactyli. ' The coracoids overlap, the left passing under the right, as in Ardea, &c., a very 

 rare thing for an arboreal Bird. The clavicles do not unite below, and the shoulder of each 

 bone is enlarged below the head of the coracoid, by a thick prae-coracoid wedge, as in the 

 Raptores. The Sternum is small, and almost square ; the upper lips of the coracoid grooves are 

 separated by a crescentic notch, as in Picus and Ramphastos, but the grooves themselves 

 overlap. The rostrum is large, subquadrate, and separated from the angle of the keel by a 

 deep notch : this part ends behind the rostrum considerably. The keel is very shallow, but 

 reaches to the end of the bone; the costal processes are much shorter than in Picus ; but there 

 are, as in that type, five costal condyles. The outer and intermediate xiphoid bars are much 

 narrower ; the outer notch is twice the size of the inner, and all the five processes reach to nearly 

 the same transverse line, the middle reaching a little the farthest, and the outer one ending 

 soonest. In many respects the Musophaginse are intermediate between the Zygodactyli and 

 the Syndactyli. 



Family" OUCULINJE." 



Example. Cuculus canorus, Linn. 



The Cuckoos, also, are an inosculating group, but their affinities lie in the direction of the 

 Caprimulginse, as well as towards the Syndactyles. Perhaps the two most distinct types of the 

 Cuculinse are the common kind (Cuculus canorus) and Lcptosoma (for an account of this 

 latter Bird see Dr. Sclater's paper in the ' Proc. Zool. Soc./ 1865, pp. 682689). The typical 

 Cuckoo has no little affinity for the typical Goatsucker (Caprimulgvs), whilst Leptosoma is 

 evidently allied both to the Plantain -eaters and to the Rollers (Coracias, Eurystomus). In 

 Cuculus canorus the scapula is long, ensiform, gently curved, and very sharply pointed : it has a 

 blunt acromion process. The coracoid is slender in its shaft, but the head is large and hooked, 

 and the meso-coracoid bar is a very large, slightly curved bar, running out at a right angle to the 

 shaft : the epicoracoid region is wide, and the ascending hook is very sharp. The furcula has its 

 rami only gently divergent, so that it is almost V-shaped ; its tips are but little enlarged by the 

 cartilaginous segments, and it has a considerable inter-clavicle, lying in the same descending 

 direction as the clavicles, and of an oval shape : the clavicles being long, the angle of the furcula 

 is directly strapped to the top of the projecting angle of the sternal keel. The Sternum of 

 Cuculus is short, very broad, especially behind ; deep, bulging, highly cellular, and three-lobed 

 behind. In old specimens I have seen the left "notch" converted into a "fenestra." The 

 notches are oval, moderate in size, and the outer xiphoid bar is very broad and pedate : the 

 middle process is very round and emarginate, and the whole outline of the end of the Sternum 

 is nearly semicircular, the pedate extremities of the outer processes end far forwards, are very 

 oblique, and this obliquity answers to that of the two lobes of the middle plate. The costal processes 

 are high and square ; there are four pairs of condyles, which lie very close together ; there is 

 a well-defined, narrow, projecting " rcstrum," both above and below the coracoid grooves, as in the 



