2 MECOPTERA AND PLANIPENNIA 
am acquainted with many fine new species from this terri- 
tory. Only the described species that I saw in those Mu- 
seums are here redescribed, though they are not represented 
in Leyden. 
I am endebted for many interesting biological notes to 
my friend Edw. Jacobson in Batavia, whose accurate ob- 
servations are very valuable contributions to the biology 
of these so neglected orders of insects. In future 1 hope to 
collaborate with him in the same agreeable way. 
Though of little economic value the larvae of some species 
of Chrysopa and Micromus are observed by Dr. L. Zehntner 
to be useful by the destruction of Aphidae and Coccidae. 
No doubt many species and genera will still be detected 
in these orders to which so little attention has been paid. 
Their biology also will surely give opportunity to many 
interesting discoveries. 
Key to the orders. 
The imagines are slender mediocre insects, with four 
equal, narrow wings, that have many furcated longitudinal 
veins, which scarcely are connected by some crossveins. 
In rest the wings are held horizontally, the forewings 
cover than the hindwings. The mouthparts are produced 
into a long beak, at the tip of which the short mandibles 
are inserted. Antennae very long and threadlike, nearly as 
long as the wings. Legs very long and slender, longer 
than the body. Body slender. 
The larvae live, so far as is known, in the earth; they 
are carnivorous, with biting mandibles, and they pupate in 
the ground without cocon. Pupa libera. 
Mecoprera (PANORPATA). 
Scorpionflies. 
Imagines from moderately large to minute insects, with four 
nearly equal wings with a dense reticulated nervature, which 
are held rooflike in the rest. Mouthparts never forming a 
Notes from the Leyden Museum, Vol. XXXI. 
