500 CALIFORNIA ACADEMY OF SCIENCES. 



making fires more destructive, and by fewer moist sheltered 

 retreats existing there. 



Near the town of Santa Cruz have been found Nos. 1, 3, 

 5, 6, 9, 11, 12, 13, 19, 25, 26, 30, 31, 35, 39, 42, and most of 

 them below 200 feet only. On the slope of the mountains 

 northward where the pass marked 2216 crosses the summit, 

 the exposure to the sun seems too great for many to live 

 except in the deep canons, but on the northerly descent 

 Nos. 1, 5, 9, 11, 25, 26, 30, 33, 39, are found near the reser- 

 voir, about 1400 ft. alt., and down to the base of the range, 

 where a form occurs between 30 and 32 in character. 

 No. 42 lives about some little marshy lakes at summit of 

 the pass, where others would doubtless exist if they ever 

 got there. Those of Santa Clara Yalley occur sparsely, from 

 the foot of the pass northward, to Black Mt., where the 

 fossils are found up to about 2300 ft. west of the peak, but at 

 that elevation I found only No. 17 with 42, along a perma- 

 nent little springbrook, none of the large species having 

 got so high up. Nos. 4 and 19a have been reported so far 

 only from the northern part of San Mateo County, near the 

 Fig. 1840 on the map, and No. 41 on rotten wood near Fig. 

 1315 close to the sea shore and northward. 



On the west slope, north of Santa Cruz, No. 3'.) reaches 

 Pescadero Creek and No. 35 to Purissima Creek, where I 

 found very large ones near its source at an elevation of about 

 1000 ft. approaching in characters No. 26, while the rest of 

 the Santa Cruz species continue into San Francisco County. 



Thus we find in these two counties only 20 species and 

 varieties, although the conditions seem so much more favora- 

 ble than east of the bay, but may safely add to them Nos. 

 32, 40, 43, found in Santa Clara County, and doubtless en- 

 tering the mountains of one or both of these. 



The height 1840 ft. on the map refers to Mt. Montora, 

 marked by a small circle west of the figure, (two summits^ 

 there not intended for towns). The fig. 1315 is San Bruno 

 Mountain, near the San Francisco boundary. 



