178 ENTOMOLOGICAL SOCIETY 
after election. Any active member in arrears for one year may, 
after one month's notification, be dropped from the rolls. No 
member in arrears shall be entitled to vote. 
SECTION 2. Corresponding members shall pay no initiation fee, 
but shall pay an annual fee of one dollar, payable at election and 
at each annual meeting thereafter. Any corresponding member 
in arrears for one year may, after notification, be dropped from the 
rolls. 
SECTION 3. Members elected within three months previous to 
an annual meeting shall not be required to pay an annual fee for 
the year in which they are elected. 
Upon recommendation of the Executive Committee, Mr. S. L. 
Elliot, of Brooklyn, N. Y., was elected a corresponding member 
of the Society. 
Dr. Marx read the following paper 
ON THE IMPORTANCE OF THE STRUCTURAL CHARACTERS OF HYPOCHILUS 
IN THE CLASSIFICATION OF SPIDERS. 
BY GEO. MARX, M. D. 
The first great subdivision of the order AranefE, based upon the struc- 
tural characters alone, is that into the two sub-orders : Dipneumones, or 
spiders which possess two lamellar tracheae or lung-sacs, and Tetrapneu- 
mones, or those with' four lungs.* 
The species of these two sub-orders are distinguished not only by the 
number of their lung-sacs, but by other structural differences, as the shape 
of the cephalothorax and abdomen, the size of the legs, the form of the 
trophi, male palpus and spinnerets; in short, by their entire morphological 
appearance. 
But there is in the Dipneumones a small group of families which present 
in one respect or another certain affinities with the Tetrapneumones. This 
relationship manifests itself, however, not so much in the general appear- 
ance of these animals as in a more or less distinctly expressed similarity 
* We have also a division of this order into seven tribes ("somewhat like 
sub-orders), which are founded upon biological facts : (i) In regard to the 
kind of web or net they spin, as Orbitelarice, making a round, geometrical 
net; Retitelarice, making a snare or loose reticulum ; Tubitelarice, those 
which attach to their flat, horizontal catch-web a tube in which they dwell 
and watch; and the Territelarice, which make a weaving in or on the 
ground (Trap-door spiders and others) ; and (2) in regard to the mode of 
running, as Citigradce^ or swift runners ; Laterigradce, or side runners ; 
and Saltigradce, or jumping spiders. The Territelariae alone represent the 
Tetrapneumones, while the six other tribes constitute the Dipneumones. 
