List of the Fauna of the County. 177
are not able to make excursions to those seas where the
different forms are most common. The discrimination of
species is rendered additionally puzzling in consequence of
each author on the subject adopting a classification and
nomenclature of his own, or at all events giving names to
varieties which other students may consider to belong to the
typical species. In the foregoing orders of Mammalia I
have been able to give the results of my own observations,
but here, of course, I must depend on records only, and shall
claim as belonging to our Essex fauna any cetaceans taken
in our rivers or on our coasts. Many of these records
are quite useless from the want of a correct description of
the animal. The terms "Bottle-nose," "Fin-back," and so
on, being evidently often very loosely and inaccurately
applied, and of no assistance in identifying the true name of
the captures, I have been obliged to pass over many observa-
tions from inability to recognise the species recorded. As
might be expected from its size, the River Thames appears to
have been very productive in species, and the records are the
more valuable as the species have generally been identified
by competent naturalists, as a result of the ease of access to
London.
Mystacpceti. Balaenopteridae.
Balaenoptera musculus. The Rorqual.—This whale, one
of the largest animals, has occurred on our coasts several
times. One was taken in the Thames in May, 1859 ; and in
the 'Zoologist' for 1849, p. 2620, is recorded the capture of
a "finner whale" at Grays, of the length of 58 feet, and a
girth of 30 feet: judging by these dimensions it was probably
an example of this species.
B. rostrata. Lesser Rorqual.—This is one of the best
marked and most easily distinguished species of the family,
and at the same time one of the most common on our coasts.
It has occurred in the Thames several times, John Hunter
describing, in the 'Philosophical Transactions' for 1787, one
from this river; another was also recorded and figured in the
'Zoologist' for 1843, p. 33, and is now preserved in the British
Museum.
Y