LORQUINIA 
21 
QuKRCUS CALiFORNiCA, (Torr.) Cooper. (California Black Oak). 
Differing greatly from all other Pacific oaks, it attains an height of 
seventy-five feet, but at high elevations it is much smaller, often under 
twelve feet. It is found in Southern California but is very common in 
the northern part of the state on mountain slopes, valleys, canyon 
bottoms and places characterized by dry gravelly soils and rocky sur- 
roundings where there is practically no soil. It is usually found ming- 
ling with California Laurel ( Umbellularia californica, (Hooker and Ar- 
nott, Nuttall), Western Dogwood (Cornus nutallii, Audubon) and 
Canyon Live Oak. It is usually largest in sheltered locations. 
QUERCUS DENSIFLORA, Hooker and Arnott. (Tanbark Oak). 
Of extensive use in the tanning processes, this tree has a smooth trunk 
and reaches a height of about eighty-five feet, but becomes very 
stunted at high elevations. It occurs from Oregon to Southern Cali- 
fornia on borders of mountain and foothill streams and revines in rich 
sandy and gravelly soils, and usually mingles with the California Red- 
wood {Sequoia sempemrens, Endlicher) and Douglas Fir. In 1866 
Oersted called this oak Pasatnia densiflora. The characters of its in- 
floresence distinguishes it as being the connecting link between the 
oaks (Quercus), and the chestnuts (Castanea) • There is a variety of 
this species, Quercus densiflora echinoides, (R. Brown) Campst. 
CECIL HART, 
Montebello, Cal. 
BUTTERFLY COLLECTING IN PLACERITA 
CANYON, CALIFORNIA 
On September 12, 1916, I went to Placerita Canyon, the road to 
which branches off from the main highway between Newhall and 
Saugus. 
I captured the following species: Pyrgus ericetorum, Lemonias 
virgulti, a Coenonympha, Pamphila Columbia and nearly succeeded in cap- 
turing a second ericetorum. This Pyrgus seems to be very common in 
both Placerita and Bouquet Canyons, but is exceedingly wary and swift 
of flight. I noticed at least a half dozen flying through the canyon 
but succeeded in capturing only the one. 
Earlier in the season I captured Colias barbara, Thecla dryope or 
californica— a very large and light specimen —Lj;caena battoides and 
Melitaea chalcedon. 
