28 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



tula, hardly mixed with any other species, and containing, so far as 

 could be discovered, no perfect specimens or lower valves. 



Stratum A^ is regarded by Mr. Hemphill as the outcroi)piag of an 

 extensive formation, probably underlying the whole of the level land 

 back to the bluffs, and presenting estuarine characters. It is sur- 

 mounted by, or passes into, a fine sandy deposit (B^), at least seventy 

 feet thick in some places, containing fossils scattered through it, and it 

 is in this stratum that the fossils from the well were found. In nearly 

 all the wells that have been sunk in San Diego, fossils have been found, 

 showing that the bed is of wide extent as well as of great thickness. 



The following fossils were afforded by stratum A^ : — 



Plioladidea ovoidea, 

 Solecurtus caUfornianus, 

 Macoma sahulosa f 



Tellina Bodegensis, 

 Donax flexuosus. 

 Mactra falcata. 

 dementia suhdiaphana. 

 Chione simillima. 

 Chione succincta. 

 Dosinia ponderosa. 

 Saxidomus aratus jun. 

 Petricola pholadiformis f 



Cardium procerum. 

 Ostrea lurida. 

 Anomia limatula. 

 FissurelUdea callomarginata. 

 Crucihulum spinosum. 

 Cerithidea sacrata. 

 Drillia penicillata. 

 Scalaria indianorum. 

 Eanella muriciformis. 

 N'assa fossata. 

 Nassa tegula. 

 Cerostoma Nuttallii. 



From the well-digging in stratum B^ came, — 



Venericardia monilicosta. 

 Area microdonta, 

 Leda coelata. 

 Pecten expansus. 

 Janira dentata. 

 Mamma nana. 



Crepidula princeps. 

 Turritella Cooperi. 

 Turbonilla sfylina. 

 I^assa mendica. 

 Cyliclma alba. 

 Cadulus fusiformis. 



To which may be added the following species not enumerated from that 

 locality in the list (pp. 11-12) in these Proceedings, but also obtained by 

 Mr. Hemphill: — 



Glottidia alhida Hds. 

 Xylotrya sp. (tubes). 

 Cryptomya californica Conr. 

 Solen rosaceus Cpr. 

 Solecurtus caUfornianus Conr. 

 2Iacoma expansa Cpr. 

 dementia suhdiaphana Cpr, 

 Cardium centifilosum Cpr. 

 Lucina Nuttallii Conr. 

 Lucina acutilineata Conr. 



Lucina tenuisciiJpta Cpr. 

 Gryptodon fiexuosus Mont. 

 Modiola recta Conr. 

 N'ucula exigua Sby. 

 Acila Lyallii Bd. 

 Pecten hastatus Sby. 

 Janira florida Hds. 

 Ostrea concJiaphila Cpr. 

 Placunanomia macroschisma Desh. 

 Tornatina eximia Bd. 



