108 ENTOMOLOGICAL SOCIETY 
Two distinct series are indicated by the venation, according to 
the position of vein 10. In one series it arises from the subcostal 
before the end of the cell, in the other it arises from a stalk with 
7, 8, and 9. 
In discussing this paper, Dr. Marx remarked that in Arachnida 
the formation of the claw is no good character for classification, 
the character varying according to the species. 
Mr. Howard exhibited drawings of some new and remarkable 
genera of Ckalcididcz from southern Florida and California. 
Informally, various subjects were then discussed : The seat of 
the poison gland in scorpions ; the poisonous or harmless nature 
of the larger centipedes ; the decrease in size of the latter after be- 
ing placed in alcohol ; on Julus and Chauliodcs being attracted 
by sugaring trees. 
DECEMBER 8, 1887. 
Thirteen persons present. Vice-President Morris in the chair. 
Dr. Marx read the following paper : 
ON THE MORPHOLOGY OF SCORPIONID^E. 
BY DR. GEORGE MARX. 
In studying the morphology of the Scorpions, as far as the limited num- 
ber of species at my disposal allows me, I have noted a few points which 
seemed to me to be of general interest. 
Allow me first to draw your attention to a peculiar and remarkable con- 
dition in the organization of the Scorpion, viz., that of an intense concen- 
tration and aggregation in the anterior region of the body, in opposition 
to an exaggerated extension or elongation in the posterior part. 
We know that the Arachnids are acephal, that early in their embryonic 
evolution the development of the head was interrupted, that it was, so to 
speak, swallowed up by the more intensified development of the thorax; 
in contradistinction to the formation of the cephalothorax of the crusta- 
ceans, where the head, in the course of its development, became simply 
blended or coalesced with the chest : the absence of the two principal attri- 
butes of the head, the antennae and the true eyes, in the Arachnids, is suf- 
ficient proof of this. But, in addition to this, we find in the anterior part 
a state of aggregation, which seems so much the stranger if we compare 
it with the extravagant and lavish state of extension in the posterior. We 
need only to examine the sternal side of the cephalothorax to notice at 
once the crowded condition of the joints of insertion of the appendages. 
We see that some parts, which are in allied orders, well developed and oc- 
