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TRANSACTIONS OF THE SECTIONS. 79 
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Supplemental Notice on the Geology of Lundy Island. 
By the Rev. D. Wittiams, F.G.S. 
In a former notice the author described some remarkable dykes in the slate and 
granite of this island, and now exhibited a series of rock specimens showing every 
intermediate condition between true granite and trap by the gradual introduction of 
hornblende and lime. These specimens were obtained at the junction of the granite 
with the slate rock at the south-east and south of the island. The author called 
attention to the abundance of carbonate of lime in some of the primary rocks, from 
which he believed it had in many instances been dispelled by heat. 
On the Geology of portions of South Wales, Gloucestershire and Somerset- 
shire. By Sir H. T. De xa Becue, F.R.S. 
ZOOLOGY anp BOTANY, 1nctupinc PHYSIOLOGY. 
On the recent Species of Odostomia, a Genus of Gasteropodous Mollusks in- 
habiting the Seas of Great Britain and Irelund. By J. G. JErFREYs, 
F.RS,., FLAS. 
‘Tue author, after a few preliminary remarks, gave an historical account of the 
genus, and proposed the coalition of all the species now composing the separate 
genera of Odostomia, Chemnitzia and Eulimella, in one genus, treating the others 
as subgenera; and he founded this view upon his observations of the animals, as 
_ well as on the shells, of each of those so-called genera. After describing the charac- 
_ ters and habits of these mollusks, he gave a synoptical view of the species, thirty- 
: two in number ; of these, nine (viz. notata, alba, dubia, acuta, diaphana, dolioliformis, 
_ fenestrata, clathrata and formosa) he described for the first time. The author then 
_ proceeded to an elucidation of their synonymy, which was previously in a state of 
_ confusion, and the following is the result of his researches :—Out of the thirty-two 
species enumerated and described by him, nine were new and hitherto unpublished ; 
, nine had been described and figured by Philippi as Sicilian shells ; one by Recluz as 
French ; ten by Lovén as inhabiting the Scandinavian coasts ; seven by Searles Wood 
as crag fossils; and one (for which the author proposed to restore the Linnean name 
of lactea for elegantissima) as indigenous to the middle and south of Europe. 
(This paper is published entire in the Annals of Natural History for 1848.) 
On the Os humero-capsulare of the Ornithorhynchus. 
By Prof. Owrn, U.D., F.RS. 
_ He referred to the discovery by Prof. Nitzsch of a small accessory bone articu- 
lated to the coracoid and humerus in certain birds, called ‘os humero-capsulare,’ and 
' stated that he had discovered an ossicle attached to the head of the humerus and to 
the capsule of the shoulder-joint of the Ornithorhynchus paradoxus. It was equally 
distinct from the proximal epiphysis forming the head of the bone, and from that 
‘which caps the great tuberosity in the young animal, and it was present in full- 
grown Ornithorhynchi. It appeared to have escaped the notice of Meckel, and although 
‘but a small instance of resemblance to birds, was interesting as an additional illus- 
tration of the affinities of the paradoxical mammal. 
On the Communications between the Tympanum and Palate in the Crocodiles. 
By Prof. Owen, ID., FLRS. 
Prof. Owen referred to the discrepancy in the opinions of anatomists relative to 
_ the small perforation in the basisphenoid behind the posterior aperture of the nostrils 
in the crocodiles. It was called ‘arterial foramen’ by Cuvier in his ‘ Ossemens 
_ Fossiles,’ and was described in the ‘ Legons d’Anat. Comparée, 1836,’ as “ leading 
“to a canal which bifurcated as it ascended, one branch traversing the sphenoid, the 
other the occipital to terminate in the ear-chamber ;” but what passes through it, 
