number of names resulting from these
exceptions is becoming so large that some zoologists fear that the
chaotic condition of nomenclature in the previous century will return.
Those who hold such fears maintain that adherence to the rules of 1901,
or to the Law of Priority, or at least to some rules, clearly is
desirable. Certainly there is much logic in that view. According to the
rules, _Nycteris_ is the correct name of the bats concerned. According
to the Commission, it is well to use instead the name _Lasiurus_.
Perhaps the time has come to follow the rules and use _Nycteris_. But,
because of the possibility that the Commission will return to its
policy of 1913 and recommend only a few instead of many exceptions to
the rules, the generic name _Lasiurus_ is tentatively used in the
following accounts.

Genus Lasiurus Gray

Hairy-tailed Bats

1797. _Nycteris_ B[orkhause]n, Der Zoologe (Compendiose Bibliothek
gemeinnuetzigsten Kenntnisse fuer alle Staende, pt. 21), Heft 4-7, p.
66. Type, _Vespertilio borealis_ Mueller [= _Lasiurus borealis_].
_Nycteris_ Borkhausen is a homonym of _Nycteris_ G. Cuvier and E.
Geoffroy St.-Hilaire, 1795, type _Vespertilio hispidus_ Schreber,
1774 [= _Nycteris hispida_], from Senegal. Although _Nycteris_
Cuvier and Geoffroy St.-Hilaire is a _nomen nudum_, Opinion 111 of
the International Commission of Zoological Nomenclature establishes
the name as available for a genus of Old World bats. On this basis,
_Nycteris_ Borkhausen is not available for the New World genus.
_Nycteris_ E. Geoffroy St.-Hilaire, 1803, is a synonym of
_Nycteris_ Cuvier and Geoffroy St.-Hilaire, 1795, as given status
by the Commission.

1831. _Lasiurus_ Gray, Zool. Misc., No. 1, p. 38. Type,
_Vespertilio borealis_ Mueller.

1871. _Atalapha_ Peters, Monatsber. K. Preuss. Akad. Wiss., Berlin,
p. 907, and other authors [_nec Atalapha_ Rafinesque, 1814].

_Type species._--_Vespertilio borealis_ Mueller.

_Diagnosis._--Interfemoral membrane large and most of its upper
surface furred; mammae 4; third, fourth and fifth fingers
progressively shortened; ear short and rounded; skull short and
broad; nares and palatal emargination wide and shallow (width
transversely exceeding length anteroposteriorly); sternum
prominently keeled; i. 1/3, c. 1/1, p. 1/2 or 2/2, m. 3/3; when
two upper premolars present, anterior one minute