444 Zoological Society. 



spine, and two concentric arches or circles below, the inner one con- 

 sisting of three elements, to which he gave the names hctmapojihyses 

 and hcEmal spine, and the outer one formed by the ribs and sternum. 



He had arrived, he said, at this idea by observing the inner or true 

 haemal arch coexisting with the costo-stemal arch in many animals, 

 and referred especially to the skeleton of a lizard in the British Mu- 

 seum as illustrating his discovery ; and regretting that the laws of 

 that Institution preve'hted his exhibiting it at the Meeting, he showed 

 the hseraapophyses in enlarged diagrams of the cervical and dorsal 

 vertebrae, and contrasted his ideal vertebra with diagrams of those 

 given by Geoffroy St. Hilaire and Professor Owen. The bones, 

 which Dr. Melville stated Sir P. Egerton had rediscovered in the 

 Ichthyosaurus, and called ' wedge-bones,' were the true haemapo- 

 physes, and he referred to a work by Camper, in which the cervical 

 haemapophyses had been previously described. 



The bone which had been called the body of the atlas was the 

 hsemapophysis of the occipital vertebra ; and the * odontoid process ' 

 was the true body of the atlas. The bones which Professor MUller 

 had defined as the inferior transverse processes in fishes, and which 

 Professor Owen had called ' parapophyses,' were the true hsemapo- 

 physes, and the term * parapophyses ' ought to be abolished, as it 

 had been applied to several distinct elements. True hsemapophyses 

 were sometimes autogenous, sometimes exogenous. 



Adverting to the pleurapophyses or pleursJ elements of the ver- 

 tebrae. Dr. Melville alluded to Miiller and Thirles' discovery of these 

 in the lumbar and sacral region, where they had been called ' trans- 

 verse processes,' and he exhibited the sacral vertebra of an ' iguano- 

 don,' showing the articular cavity for the sacral rib. 



With regard to the exogenous processes of the vertebrae, which 

 Professor Owen had called * diapophyses,' Dr. Melville exhibited the 

 vertebral columns of some quadrupeds, showing that they sent oflf 

 a process backwards in the dorsal vertebrae, and were continued into 

 the lumbar region by such posterior processes, and not by the pro- 

 cesses which Professor Owen had called diapophyses in the lumbar 

 region. Understanding that Professor Owen had proposed names 

 for these mere subdivisions of the diapophyses, Dr. Melville strongly 

 deprecated the overloading this diflEicult part of anatomy with unne- 

 cessary names. He also animadverted on Cuvier and M. De Blain- 

 ville for having neglected to describe these modifications of the trans- 

 verse processes. Dr. Melville pointed out in the vertebrae of an 

 ant-eater and armadillo the processes which project forwards from 

 the anterior zygapophyses, and which he believed Professor Owen 

 called the * epizygapophyses ' — (the Professor here stated that he had 

 given that name to the superior articular processes in serpents, which 

 were not homologous with the processes alluded to by Dr. Melville, 

 and to which Professor Owen had assigned a distinct name). Dr. 

 Melville went on to demonstrate these anteriorly projecting processes, 

 and stated that the Edentata had no posterior or backwardly pro- 

 jecting processes from the diapophyses. With regard to the parts 

 called ' parapophyses' by Professor Ow^en in the cranial vertebrae. 



