598 PROCEEDINGS OF THE NATIONAL MUHEUM. vol.52. 



9. OPHIOGOMPHUS BISON Selys. 



Two specimens were taken on a small gravel bar in the San Lorenzo 

 at Big Trees, where two exuviae were fomid on the base of an alder 

 overhanging the stream. Two other imagoes were taken on a riffle 

 at the Rincon powder works. These catches are interestmg in that 

 this species had been known only from a female, the type, which, de- 

 posited in the McLachlan collection, was labeled "from Santa Cruz, 

 Cahfornia." Probably the type had been taken on the San Lorenzo 

 River. 



10. OCTOGOMPHUS SPECULARIS (Hagen). 



The exuviae of this species were abundant with the Cordulegaster 

 exuviae on the middle reaches of Zyante Creek, but none were seen 

 below this and no imagoes were seen. 



11. AESHNA CALIFORNICA Calvert. 



Several were seen above Rincon. 



12. AESHNA MULTICOLOR Hagen. 



Several seen along the railroad above Rincon. 



LOS GATOS RIVER, SANTA CLARA COUNTY, CALIFORNLA. 



Excepting for Argia vivida Hagen and a few Cordulegaster and 

 OctogompTius on its headwaters, this stream is practically without 

 Odonata. This is because of the very dense shade on the upper part 

 of the stream, and the fact that so much water is removed by irri- 

 gation and for the town of Los Gatos that in any ordinary season 

 the river is entirely dry in its open portion below Los Gatos. 



From June 6 to 9 I collected at points on the Napa River. This 

 small river, lying entirely in Napa County, drains a shallow valley 

 on the north side of San Francisco Bay. This valley, lying just east 

 of the main range of the Coast Mountains, is ratlier dry so that it 

 resembles the Sacramento Valley. At Napa, where the first collec- 

 tions were made, the river is a tide stream and gave no Odonata. 

 At Calistoga, the only other ])lace examined, the river was also 

 without Odonata. 



NAPA, NAPA COUNTY, CALIFORNIA. 



The collecting at Napa was done on the extensive estate of the 

 Insane Hospital. A small, clear mountain stream, which comes 

 down through a deep ravme east of the asylum, is led into a series 

 of ponds and reservoirs. These swarm with Odonata. 



1. ARCfflLESTES CALIFORNICA Mc Lachlan. 



The shallows about the main pond swarmed with the nymphs of 

 this. One teneral was taken. 



2. LESTES, species. 



This species was common on the pond. 



3. ARGLA VIVIDA Hagen. 



Common along the lower half of the stream. 



