24 ENTOMOLOGICAL NEWS. [Jan., '07 



ejections but common in parts of the West is C. zerce. Lyccsna 

 $e,rce$, supposed . to be extinct, has come to life, but is very 

 local. Lyccsna lotis is a very rare butterfly if it is a valid 

 species, as the writer never saw one. The locality is Mendo- 

 cino, Calif. L. aster from Newfoundland is a great rarity in 

 collections', Lyccsna striata is also unknown to the writer of 

 this article. Neophasia tcrlooti was described in 1 869 and not 

 again found until 1900. Fieris ochse?iIieimeri from Alaska is in 

 two collections only. Anthocharis pima was unknown in col- 

 lections for a number of years. Arizona and its fauna is be- 

 coming better known every year, although there are vast tracts 

 and many mountain ranges yet to be explored. Colias boot hi 

 is probably very common in Boothia-Felix, but there is only 

 one specimen of it in the United States. It is probably the 

 rarest butterfly that is still living. Colias behri is a good illus- 

 tration of a butterfly that is rare in collections on account of a 

 limited geographical range. It is an alpine species found about 

 the Yosemite Valley, California. The golden Par?iassius evers- 

 manni is a very great rarity in collections, but is beyond doubt 

 very common in its native haunts. Papilio nitra, i?idra, per- 

 gamus, brevicauda, pilumus, cresphonti?ius are all good ones and 

 lucky the collector that has them all.. Ancyloxypha longleyt 

 was found near Chicago, Illinois, where there are numerous 

 collectors, yet there is but one specimen known. There are 

 certain names in the Hesperidae that represent more or less 

 doubtful species and we will only refer to rare valid species. 

 The following are rare in collections : lasus, cabelus, rhesus, 

 earns, licinus, meskei, verus (the latter is a variety of nemorurri), 

 morrisoni, chusca, mardon, bellus, loammi, lunus, panoquinoides , 

 errans, pytho?i, cestus, yehl, lagus, arogos, arabus, Carolina, 

 libya, outis, drusius, hesus, copafui, streckeri. To refer to the 

 original question again. The rarest butterfly found in North 

 America may be said to be a valid species, represented in a 

 single collection, by one specimen, and it the most difficult 

 species of which to obtain additional material. What is it? 

 The rarest species in nature is the one confined to the least 

 geographical area and producing the least number of indi- 

 viduals. What is it ? 



