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: temiicornis, 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;" 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^C. 



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. 



PARNIDyE. 



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. 



