104 CALIFORNIA ACADEMY OF SCIENCES. 



Cytilus. C. sericeus, Lake Tahoe and north. 



Limnichus. L. calif ornicus, common by washing the 

 margins of streams; Pomona, Riverside, Palm Springs, 

 San Bernardino Mountains, etc.: perpolitus, less com- 

 mon, or at least more local; I once took it in some 

 numbers along the Santa Ana River at Riverside and 

 again near Pomona, April to June: nebulosus, not com- 

 mon; Pomona, Riverside, Pasadena: tenuicornis, once 

 found in numbers on a wet, springy hillside in the San 

 Bernardino Mountains, elevation 6,000 feet: naviculatus, 

 not rare at Los Angeles and Riverside: analis will 

 probably be found in Southern California, as it is re- 

 corded from "California and Arizona;' 7 my specimens 

 are from the middle coast region: perforatusis described 

 from Santa Clara County. 



Bothriophorus. B. minutus, Riverside and Yuma, 

 along the margin of streams. 



GEORYSSID.E. 



Georyssus. G. californicus was taken once along the 

 Truckee River, near Lake Tahoe; probably common 

 enough in the middle and northern parts of the State, 

 and may very likely yet be found in the mountains in 

 the south. 



PARNID^E. 



Psephenus. P. falli, rare; a small colony once found 

 running over the rocks lying unsubmerged in the 

 middle of a shallow stream near Pomona, June 4; a 

 single specimen taken along a mountain stream at 

 Arrowhead Springs, May 30: veluticollis occurs in Men- 

 docino County. 



Lara. L. avara is northern. 



