258 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
sus) , thus paralleling in an interesting way the island-like distribu- 
tion of certain boreal species on the cool mountain-tops of the 
Transition belt {e.g., among Orthoptera, Podisma glacialis). 
Entering this broad area of sandy land from the southwest, 
these campestrian sand-loving species of austral descent over- 
spread it far to the northeast; and following up the course of the 
north- and south-running river valleys, with their exposed bars 
and shores and the scantily clad plains between, they spread far 
inland, in some cases even to the bases of the high mountains. 
Later, when the general spread of plant life had clothed the 
land surface with vegetation, and the accumulation of vegetal 
debris and formation of humus had improved the soil and devel- 
oped its moisture-retaining properties, the phytophilous and hum- 
icolous species came. 
In a similar manner the halophile species of the tidal marshes 
and immediate seashore became dispersed (e.g., among Orthop- 
tera, Conocephalus spartinae, Orchelimum concinnum, Trimero- 
tropis maritima, and perhaps Paroxya clavuliger. 
Local Distribution. — Whatever their geographic or zonal dis- 
tribution may be, whether eastern or western, boreal, austral, or 
transition, Orthoptera differ much specifically in the character 
of the haunts which they frequent, and consequently may be 
arranged in groups of species associated through a common fond- 
ness for surroundings of a particular type. 
It is a stimulating test of one's knowledge of their habits, ability 
to discriminate environmental conditions, and judgment of prob- 
abilities, to make a list of the species likely to be found in a given 
spot, and by collecting strive to verify it. "Can I expect to find 
such and such a species here? If not, why not?" When suffi- 
ciently experienced, a high degree of accuracy is possible. 
It scarcely need be said that any classification of habitats will 
vary much in details according to the habits of the group chosen. 
Compare for instance, the Locusts and the Crickets in reference 
to the time of day when active and the proportionate number 
living in the ground, on the ground, and above the ground. 
After a wide experience in New England, the southeastern 
States, and on the Pacific coast, the author proposed a classifica- 
tion of Locust habitats and societies only (Publ. 18, Carnegie 
Inst. Wash., 1903). This was based on the physical character of 
