302 Annals Entomological Society of America [Vol. VIII, 
versity, where these. were’ most fully observed, exuviae were 
found in abundance two miles below the lowest point on the 
creek at which any imagoes were seen, and imagoes were com- 
mon on the divide at the head of the creek, where few exuviae 
were found. These observations were checked in other parts 
of California. It is this migration upstream which keeps 
Cordulegaster and Octogomphus limited in their distribution 
to the head waters of these torrents and prevents their even 
occasional appearance in the lower level reaches of these same 
streams. 
Cordulegaster is one of those strange insects with unusual 
structure and equally unusual habits, and as it lives on the 
headwaters of the wildest mountain streams, but little has 
been known concerning it. The. ovipositor of the female 
is very long and heavy, trough-shaped affair and very blunt. 
After many conjectures as to how it was used, Dr. Ris finally 
succeeded in observing the female of a Swiss species in the 
act of ovipositing. This for a dragonfly was a very unusual 
operation. Most Zygoptera oviposit by inserting eggs in 
vegetable tissues with the aid of their needle-like ovipositors. 
Most Anisoptera oviposit by washing the eggs into the water 
from the tip of the abdomen. Cordulegaster does_ neither. 
The female observed flew hastily up the creek examining each 
sandy shallow, until she finally found one protected on three 
sides by stones in the water, and not over an inch deep... She 
hovered over this and dropping her long abdomen into a 
vertical position made a series of dips or backward. plunges, 
at each dip thrusting the tip of the abdomen with its heavy 
blunt ovipositor thru the shallow water into the sand beneath. 
After perhaps a half dozen thrusts she flew up the creek a 
short distance and finding another shallow to her liking repeated 
the process. The whole process rather closely resembled the 
manner of oviposition of some of the crane flies. 
In the canyon back of Mt. Lowe at Pasadena, Cal., I had 
an opportunity of observing the habits of the tropical Palto- 
themis lineatipes. This is a large red-bodied hbelluline. with 
habits of flight, which in part resemble those of a corduline 
and in part the high flying habits of a Tramea or Pantala. ‘The 
nymphs are as interesting as the adults and were very abundant 
in the clear mountain stream. This flows thru.a gorge whose 
