350 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. 
monly a marked ‘difference i in the dips of the Monterey strata and 
those of the Vaqueros sandstone, and an unconformity is therefore 
believed to exist generally between the two formations. 
Few localities in the Vaqueros sandstone are fossiliferous, but such 
as are yield an abundant fauna of unmistakable lower Miocene age. 
As would be expected in a formation composed largely of conglom- 
erates and coarse sandstones, the Vaqueros contains a shallow water 
or littoral fauna. 
The following species have been found in the Vaqueros formation 
within the Santa Cruz quadrangle: 
BRACHIPODA. 
Terebratalia (aff.) occidentalis Dall. 
PELECYPODA, 
Area microdonta Conrad. Pecten andersoni Arnold. 
Callista, species, v. Pecten branneri Arnold. 
Cardium vaquerosensis, new species. Pecten estrellanus Conrad 
Chione temblorensis Anderson. Pecten magnolia Conrad. 
Dosinia conradi Gabb. Phacoides richthofenit Gabb. 
Dosinia mathewsonii Gabb. Phacoides acutilineatus Conrad. 
Dosinia cf. montana Conrad. Pinna alamedensis Yates. 
Dosinia ponderosa Gray. Psammobia edentula Gabb. 
Glycymeris branneri, new species. Solen, species, v. 
Leda cahillensis, new species. Tivela ineziana Conrad. 
Ostrea titan Conrad, new variety, v. Yoldia submontereyensis, new species. 
Panopea generosa Gould. 
GASTEROPODA. 
Act@on, species, Vv. Macron, species, v. 
Agasoma kernianum Cooper. Neverita callosa Conrad. 
Agasoma santacruzanda, new species. Olivella, species, v. : 
Conus oweniana Anderson. Phos, new species, v. 
Crepidula princeps Conrad. Sigaretus scopulosus Conrad. 
Cuma biplicata Gabb. Turritella ineziana Conrad. 
Galerus inornatus (?) Gabb. Turritella ocoyana Conrad. 
PISCES. 
Galeocerdo productus Agassiz. Lamna clavata Agassiz. 
Monterey shale——As with the previously described Tertiary forma- 
tions, the areal distribution of the Monterey is controlled largely by 
the northwest-southeast structural lines of the region. 
The largest area of Monterey shale on the amadhanyelle | is that flank- 
ing the west side of the Santa Cruz Range and extending from the 
city of Santa Cruz northwestward for 30 miles to a point slightly 
north of Pescadero Creek. At the base of the shale through most of 
this region is a body of sandstone, varying in thickness from 50 to 
200 or 300 feet. The maximum thickness of the Monterey for the 
quadrangle is about 2,500 feet. 
