PALEONTOLOGY OF THE SURVEY. 195 



PERNA, Urn. 



Perna MONTANA, PI. — , fig. — . — Elevated, anterior margia nearly straight; hinge line 

 slightly incurved. 



Locality. — San Buenaventura, Santa Barbara county. 



An imperfect cast, about 4J inches in height, allied to P. maxillata, of Virginia, from which 

 it differs in having a straighter front and incurved cardinal margin. (Not illustrated.) 



UNIVALVES. 

 trochita. 



Trochita costellata, pi. 7, fig. 3. — Convex or convex-depressed ; volutions 3^ ; suture 

 distinct ; surface irregular, and marked by radiating interrupted ribs, which are obsolete or 

 wanting above, and distinct, though little prominent, towards the periphery ; apex not central 

 and slightly prominent. 



Locality. — Gaviote pass. 



A cast in sandstone. There are two very perfect casts, one more elevated than the other, 

 with a less distinct suture and radii. 



TUREITELLA, La?n. 



TuRRiTELLA Inezana, PI. 8, fig. 4. — Subulate, thick ; sides of volutions straight, with an 

 obtuse carina on each side of the suture, and contiguous to it. 



Locality. — Santa Inez mountains. 



A large species with the last volution If inch wide. The specimen is an imperfect cast with 

 portions of the crystallized sh( remaining. There are traces of 2 or 3 revolving lines on one 

 of the volutions. 



Turritella variata, pi. 8, g. 5. — Subulate, volutions with straight sides, each with 4 to 

 6 revolving prominent ribs, bo ly whorl with a broad furrow revolving above the angle of the 

 base. 



Locality. — Santa Inez mountains. 



A variable species ; one specimen of which shows 2 revolving lines on the upper part of each 

 whorl distant from 3 equidistant ribs beneath, all nearly or quite equal in size. Others have 

 6 unequal equidistant ribs ; but I believe the species is always excavated at base. 



NATICA. 



Natica Inezana, pi. 10, figs. 5 and 6.— Subglobose ; whorlsS ; spire prominent; volutions de- 

 pressed or slightly channelled above, scalariform ; umbilicus of ovate-acute outline, patulous 

 towards the base. 



Locality. — Santa Inez. 



A large species, abundant, but the specimens are imperfect. Portions of the shell remain on 

 the cast, and are crystallized. Height 2f inches. 



MULTIVALVES. 



Balanus Estrellanus, pi. 8, fig. 1. — Very large, subconical, not elevated; valves sculptured 

 with close, undulated, or very irregular radiating lines. 



Locality . — Estrella . 



Height about 2 inches ; width 2h inches. A single specimen is in the collection, with its ex- 

 ternal characters almost obliterated. 



