364 MR. R. I. POCOCK ON TIE [Apr. 21, 
The Austro-Malayan Islands, which were referred by Wallace 
to the Australian Region, belong, according to their Arachnid 
fauna, to the Oriental Region—Wallace’s line being practically 
non-existent. 
Sonoran Region. 
Dipluride. 
Diplurine.—Brachythele : California, Texas, &e. 
Macrothelinee.—Hvagrus : Idaho. 
Mecicobothriide.—Hewura : Oregon and Washington State. 
Brachybothriidee.—Lrachybothrium : From Texas and Virginia to 
British Columbia. <Atypoides: California. 
Atypidee.—<Atypus: Eastern States, from Wisconsin to Florida. 
Cyrtauchentidee.—Amblyocurenwm, Aptostichus, and Actinoxia: 
California. M/yrmeciaphila: Carolina, Virginia. 
Ctenizidee.—Pachylomerus : Carolina, Alabama, &c., Mexico. 
Bothriocyrtum : California, Utah, Texas, Mexico. 
Halonoproctidee.—Cyclocosmia : California, Alabama. Chorizops : 
Mexico. 
Aviculariudee. 
Aviculariinee.—4d phonopelma : Texas, Arizona, California. 
And perhaps others. 
Out of the above-given list of 15 genera no fewer than 10 are 
peculiar to the Region, all, that is to say, with the exception of 
Atypus, Brachythele, Amblyocarenum, and Pachylomerus, which 
are also present in the Mediterranean Region, and Hvagrus, 
which is met with in the Neotropical and Ethiopian Regions. 
This Region, including the Mexican plateau and the Southern 
States of the Union, extends northwards to the northern limits 
of the Mygalomorphe, or at least to those of the Scorpiones and 
Solifugee *. 
Neotropical Region. 
(Central America south of the Mexican plateau, West Indies, 
Bahamas, and South America.) 
The principal genera are :— 
Dipluridee. 
Diplurine.—Diplura: 8. America. Uruchus: Ecuador. 
Trechona, Melodeus, and Harmonicon: Brazil. Fufius: 
Central and South America. Trissothele: Chil. Lyci- 
nus: Argentine. 
Macrotheline.—IJschnothele: Central and South America, 
W. Indies. Hvagrus: Central America. 
Paratropide.—Paratropis : Ecuador, Amazons.  <Anisaspoides : 
Amazons. Anisaspis: W. Indies. 
Mecicobothriidee.— MWecicobothrium: Argentine. 
1 Compare also in this connection the distribution on the coast of Limulus poly- 
phemus, trom Cape Cod to the Gulf of Mexico. 
