424 CALIFORNIA ACADEMY OF SCIENCES. 52 
mens have been compared. The original specimens came 
from a bottom of volcanic ashes. 
69. Cheznomugil proboscideus (Giinther). Lisira. 
Very common in rocky places, reaching a length of 
about 6 inches; not found by us in open water. 
70. Querimana harengus (Giinther). VERDE. 
Very common in the bay and estuary; often seen swim- 
ming in schools on the surface after the fashion of whirli- 
gig beetles; occasionally taken in rock pools. Back 
bright green, in life with a large, shining, silvery spot on 
each side of the back. This spot becomes inconspicuous 
when the fish is taken out of the water, but is a prominent 
recognition mark while the fish is swimming. 
71. Agonostomus nasutus Giinther. ‘TRUCHA. 
Extremely abundant in the fresh waters of the Rio 
Presidio, especially in the swift places or ripples. It 
reaches a length of over a foot, but most of the speci- 
mens are much smaller. 
Head 4 to 4%; depth 4% to 4%; dorsal IV-1, 8; 
anal usually II, 10, very rarely II, 9; scales 43-13; maxil- 
lary 3% to 377; eye 3% to 4% ; snout 3% to: 4; pectoral 
1% to 1%; caudal equal to head. 
Body moderately elongate, not much compressed, nape 
prominent, rounded.  Interorbital much rounded, 3 in 
head. Preorbital narrow, as wide as pupil. Mouth rather 
small; maxillary reaching front of pupil; lower jaw in- 
cluded. Eye large without adipose eyelid. Teeth small, 
in villiform bands. Gill-rakers slender, short, close set. 
Pectoral short, not reaching first dorsal. Ventrals under 
middle of its length, each with a small axillary scale. 
Anal and soft dorsal with the free edge concave; caudal 
well forked. First spine of anal very short, almost ru- 
