1866. | Geology and Paleontology. 105 
must therefore be content to notice only the more important of them 
in the order in which they appear. 
Dr. Duncan’s paper on Echinodermata from the South-eastern 
coast of Arabia and from Bagh on the Nerbudda is unusually 
interesting. This paleontologist generally makes remarks worth 
reading and remembering in connection with the subjects of which 
he treats, and those contained in this memoir exhibit a more than 
common breadth of mind. Finding the species he has determined 
to indicate a Cenomanian age, he discusses the probability of the 
beds containing them belonging to that period, and devotes a special 
section of the paper to an essay on “The Impossibility of estab- 
lishing a close Synchronism between the Asiatic and other Cre- 
taceous Strata.” The remarks which follow, “ On the Identity, 
Persistence, and Variability of the Species,” are equally good and 
very suggestive. They at least show us how much we have to 
learn about the life-history of those types which we call species. 
The conclusion, that “as the different longevities of species and also 
of the individuals of species are both regulated by determinate laws, 
so are, doubtless, the apparently inexplicable associations of per- 
sistent, variable, nascent, and moribund species,” is sufficient to 
indicate the nature of the subject discussed. We can here do no 
more than call attention to the paper, which is worthy of forming 
an appendix to Mr. Darwin’s ‘ Origin of Species.’ 
The next paper consists of a letter “On the Fossil Contents of 
the Genista Cave, Gibraltar,” addressed by Mr. Busk and the late 
Dr. Falconer to General Sa J. W. Codrmgton, Governor of 
Gibraltar. The character of the extinct fauna of Gibraltar, according 
to the evidence yielded by this cave, is not a little peculiar; of the 
Mammoth, Rhinoceros tichorhinus, Ursus speleus, Hyxna spelea, 
and other English, French, and German forms, “ not a vestige has 
been detected among the fossil remains of Gibraltar.” The Car- 
nivora are, however, the most significant; “the three species of 
Felis are of African affinities, and Hyena brunnea, now for the 
first time ascertamed to have existed formerly in Europe, is at the 
present day chiefly found near the Cape of Good Hope and Natal.” 
The last-mentioned discovery opens out a very large question, or 
series of questions. How did Hywna brunnea get from Africa to 
Europe, or from Europe to Africa ? In which of these directions did 
the species migrate ? At what period did the migration take place ? 
Finally, how comes it that this 1s a South African species? Human 
remains, stone implemeuts of the polished-stone period, broken 
querns, pottery, and other objects were also found in the cave, and 
show that, geologically speaking, its contents are of no great anti- 
quity. The authors conclude their letter by two very good sug- 
gestions ; firstly, that a local museum should be formed, to contain 
