232 STALK-EYED CRUSTACEA. 
elles des points de ressemblance multipliés.” In 1852 Dana* published a 
chart to illustrate the distribution of marine animals. On this chart the 
waters of the globe are divided into five great circumterrestrial zones, whose 
potent influence controls the distribution of marine life. The limits of these 
zones are determined by isocrymal lines, or lines of equal mean temperature 
of the surface water during the coldest month of the year. The Torrid or 
Equatorial Zone is bounded north and south by the isocryme of 68° F.,— 
the limit of reef-building corals. The North and South Temperate Zones are 
included between the isocrymal lines of 68° and 35°, the North and South 
Frigid or Polar Zones between the isocrymes of 35° and 26°. 
The relations existing between littoral Crustacea from similar latitudes 
around the whole circuit of the globe make it clear that the primary faunal 
divisions should be drawn with reference to the isocrymal lines. Yet Dana + 
proceeds to base his fundamental faunal areas or “kingdoms” chiefly on 
north and south lines running across the isocrymes, in accordance with the 
general trend of the great continental shores. His Arctic and Antarctic 
kingdoms alone.are determined by latitude. Miers,{ Henderson,§ and other 
recent carcinologists have followed Dana’s method. 
But other zodlogists who have treated of the distribution of the littoral 
marine fauna have based their primary divisions on the isothermal lines. 
Thus, according to the Danish conchologist Mérch,|| the marine fauna falls 
* United States Exploring Expedition, Vol. XIII., Pt. Il., p. 1451. 
+ Op. cit., pp. 1530, 1554, ete. 
+ Brachyura of the Challenger Expedition, p. xvii, 1886. Dana’s and Miers’s primary faunal regions 
may be readily compared as follows : — 
Dana. Misrs. 
Kingdoms. Regions. 
Africo-European. . . J Europe. ee 
( W. Africa. 
( E. America. 
UW. America . . Occidental. 
Atlantic. 
Occidental 
cept W. America. 
Arctic way, Iceland, Greenland, 
Alaska, ete. 
Antarctie shores, including So. 
Aretic shores, inciuding Nor- 
~ Arctic or Boreal Circumpolar. 
Antarctic Patagonia, So. New Zealand, > Antarctic or Austral Cireumpolar. 
ete. 
§ Anomura of the Challenger Expedition, p. 197, 1888. 
|| Malakozoolog. Blatter, VI. 104, 1860. 
E. Africa 
Ouental’ 22s! Indian Ocean. ; ; 
Pacific coasts and islands, ex- Oriental or Indo-Pacific. 
