276 Dr. J. Murie on the Genus Colius. 



mise, exhibit a relationship to our form, but, like the last- 

 mentioned, very considerably modified. Their sterna have 

 quadruple notching ; but the shortness and strength of the xi- 

 phoids, depth of pectoral plates, occasional want of intercla- 

 vicle, supracoracoid foramen, &c. define them most trenchantly 

 from Colius. Their pelvis, however, has a form approaching 

 nearer to the latter than that of the Musophagidse. On the 

 other hand, a longer-beaked skull, the cranial vertex high, and 

 praemaxillse give a totally different contour. There are rudiments 

 of basipterygoids in Coracias* ; the zygomatic spicule reaches 

 thejugal; praeniaxillary hinge almost deficient; interorbital sep- 

 tum totally ossified; maxillo-palatine construction more like 

 Turacus than Colius ; mandibular and other points are all signi- 

 ficant of separation of cranial character. 



The whole of the leg-bones of the Roller are shorter through- 

 out, and especially that important one the tarso-metatarse. This 

 fact even comes out stronger when the homologous pieces of the 

 leg and wing of the genera compared are studied ; for Coracias, 

 be it observed, has a long ulna. 



There are some points in one genus of the Rollers which 

 point to alliance, even if otherwise subdued : I allude to 

 Colaris. In this form there is a progressive shortening of the 

 beak, a wider separation of the maxillo-palatines and palatal 

 plates, and, anteriorly, presence of hypocleidium and a short 

 thickish tongue. 



One short notch on each side of a massive sternum, a great 

 prow formed from keel, bifid manubrium, absence of intercla- 

 vicle, &c. distinguish the Bucerotidse. These have one dorsal 

 vertebra less. Their pelvis is vastly different in shape, propor- 

 tional length to breadth of prse- and post-acetabular areas, ischial 

 shortening, flattening, and an additional external marginal pro- 

 cess evince complete separation. Their skull is quite as sin- 

 gular ; and in limb-bones more especially, the shortening of tarso- 

 metatarsus, position of toes, and syndactylism offer the reverse 

 of coincidence to the Coly tribe, 



* Huxley states there are none, " Classification of Birds," P. Z. S. 1867, 

 p. 448. 



