Reports and Proceedings. 217 
Dr. Carte said that in a former discussion upon a paper by Profes- 
sor Jukes, relating to bones of Cervus megaceros found under cir- 
cumstances similar to the present, the differences of opinion resolved 
themselves into three hypotheses. Mr. Jukes held that the abra- 
sions were produced by pressure. Another hypothesis was, that the 
marks were produced by the hand of man. The third was, that 
they were the result of the friction of the bones lying upon one 
another, that friction having been produced by motion for which 
it was not easy to assign a cause. The last was the doctrine that 
he himself broached, and he thought that his view was borne out 
by the specimens now before them. 
II. On the 12th inst., Dr. Carte in the chair, Captain R. F. Burton, 
Her Majesty’s Consul at Santoz, was elected an Honorary Fellow. 
Mr. W. H.S. Westropp read a paper On a Trap-rock at Bray 
Head, County Wicklow. This greenstone was discovered by Pro- 
fessor Harkness, who told Mr. Jukes of his having found it. Mr. 
Jukes showed it to the writer, by whom it was examined in detail. 
After describing the position, mode of occurrence, and nature of the 
rock, Mr. Westropp brought forward arguments to prove that it was 
an intrusive trap, for it might be seen sending veins into, and cut- 
ting across beds of, the adjacent sedimentary rocks. He concluded 
by observing, that, while there was such a profusion of igneous 
rocks associated with the Cambro-silurian deposits of Wicklow, it 
was rather remarkable that one small greenstone-dyke, at Grey- 
stones, and the greenstone he had just described, were the only trap- 
rocks which had yet been found in the Cambrian rocks of that 
county. 
Mr. Juxes corroborated Mr. Westropp’s observations; and stated 
that he knew of beds of intrusive greenstone running evenly between 
other beds for miles in length and breadth, preserving almost the. 
same thickness throughout, and not appreciably altering the beds 
above or below. He also remarked that probably the igneous rocks, 
so abundant in the lower Silurian beds, had passed through the 
Cambrian beds below by few and narrow channels, such as the dyke 
described by Mr. Westropp. 
Mr. W. H. Batty then read a paper entitled Some Additions to 
the Structure of Palechinus. He stated that since his last commu- 
nication to the Society on this subject, he had been enabled to exa- 
mine an additional specimen of Palechinus ellipticus, which had 
been presented to the Geological Survey by Mr. M. G. Ryan, who 
had been fortunate enough to knock out two of these rare fossils 
from a block of limestone used in the construction of a drain at 
Bettyville, near Croome, County Limerick. Mr. Baily remarked that 
this fossil was in the state of a cast; the matrix in which it had been 
embedded, having retained the test or shell, had been left behind ; 
and he urged the necessity upon collectors of preserving both 
sides of a specimen, one of which often served to elucidate parti- 
cular parts, which may have been obscure on the other. He believed 
this fossil exhibited some additional particulars with regard to the 
