only known shell-bearing molluscs of the existing
British seas.

[20] Principles of Zoology: touching the Structure, Development,
Distribution, and Natural Arrangement of the Races of Animals, living
and extinct. With numerous Illustrations. For the Use of Schools and
Colleges. Part I., "Comparative Physiology." By Louis Agassiz and
Augustus A. Gould. Boston: Gould & Lincoln.

[21] _a_, Articulating surface of joint. _b_, Fragment of column,
exhibiting laterally the tooth processes, so fitted into each other as
to admit of flexure without risk of dislocation. The uppermost joint
shows two lateral cavities for the articulation of auxiliary arms.

[22] Perhaps one strengthening principle more might be enumerated as
occurring in this curious piece of mechanism. In the layer of the nether
plate, the fibres, instead of being laid in parallel lines, like the
threads in the moleskin of my illustration, seem to be _felted_
together,--an arrangement which must have added considerably to their
coherency and powers of resistance.

[23] Fig. 102, Clymenia Sedwicki; Fig. 103, Gyroceras Eifelensis; Fig.
104, Cirrus Goldfussii.

[24] Berosus, Hieronymus, Mnaseas, Nicolaus, Manetho, Mochus, and
Hestaeus.

[25] See Cory's "Ancient Fragments."

[26] As was common in Bible illustrations published in our own country a
century and a half ago, the old Greek artist has introduced into his
medal two points of time. Two of the figures represent _Noe_ and his
wife quitting the ark; while the other two exhibit them as seated within
it. An English print of the death of Abel, now before me, which dates a
little after the times of the Revolution, shows, on the same principle,
the two brothers, represented by four figures,--two of these quietly
offering up their respective sacrifices in the background, and the other
two grappling in deadly warfare in front.

[27] "In preparing the 'Horae Biblicae Quotidianae,' he [Dr. Chalmers]
had beside him, for use and reference, the Concordance, the Pictorial
Bible, Poole's Synopsis, Henry's Commentary, and Robertson's Researches
in Palestine. These constituted what he called his Biblical Library.
'There,' said he to a friend, pointing, as he spoke, to the above named
volumes as they lay together on his library table, with a volume of the
'Quotidianae,' in which he had just been writing, lying open beside
them,--'these are the books I use: all that is Biblical is
there.'"--_Dr. Hanna's Preface to "Dail