ART. 15 A MIOCENE MOLLUSK^ TEMBLOR RANGE WOODRING O 



June 21, 1909 (U. S. Geol. Survey Loc. No. 12453) ; Santa Marga- 

 rita (?) formation, upper Miocene. 



Reina,rks. — The 20 specimens are molds, all of which are more or 

 less imperfect. A few retain traces of shell material. One is a 

 little more convex than others. 



The long-ovate outline and submarginal spire suggest that this 

 species belongs in the group of R. tuberculata Linnaeus, as defined by 

 Pilsbry,*^ but it closely resembles a small elongate Haliotis from San 

 Benito Island off Lower California (U.S.N.M. No. 265600), that has 

 the wide, uniformly spaced, rounded spiral cords and deep narrow 

 grooves of H. fulgens Philippi, which belongs in the group of H. 

 con'ugata. More specimens are needed to determine whether the 

 Lower California Haliotis is an elongate form of fulgens or whether 

 the similarity of sculpture is attributable to parallelism. The fos- 

 sils have more uniformly spaced spiral threads and are smaller than 

 H. wal-allensis Stearns,^ which seems to be a genuine California rep- 

 resentative of the tuberculata group. In outline and size they re- 

 semble the Japanese H. japonica Keeve {tuberculata group), which 

 lacks the bulge and depression between the columellar margin and 

 the row of holes. Young specimens of the Californian H. rvfescens 

 Swainson {corruga^ta group) are more elongate than adults, but their 

 surface is undulated by coarse waves, and they have less uniform 

 sculpture and less strongly developed bulge and depression. 



The sandstone carrying Haliotis lasia was placed in the Santa 

 Margarita formation by the collectors. According to the field notes, 

 it is part of a zone of conglomerate and sandstone, and lies about 

 200 feet above a bed carrying an echinoid identified by Anderson 

 and Pack as Astrodapsis antiselU Conrad, provided the beds are 

 not overturned, though the two sets of beds were not found in a 

 continuous section. W. D. Kleinpell, of Bakersfield, Calif., who is 

 familiar with the geology of the southern Temlilor Range, has 

 kindly examined this locality and reports that the beds are not 

 overturned. According to Mr. Kleinpell, in the Salinas Valley 

 Asti^odapsis antiselU is found above the Santa Margarita formation 

 (upper Miocene) in the lower part of Keed's ^ Poncho Rico forma- 

 tion, which may straddle the Miocene-Pliocene boundary in terms 

 of the California Coast Range section as now accepted. Therefore, 

 the Temblor Range 5^<z?zc»?^is-bearing bed may be younger than the 



•PUsbry, H. A., Man. Conch., vol. 12, pp. 70, 85, 1890. 



■^ Stearus, Robert E. C, Preliminary description of a new variety of Haliotis. Nauti- 

 lus, vol. 12, uo. '.). pp. 106-107, 1899. Description of a new variety of Haliotis from 

 California, with fauual and geographical note.s. Proc. U. S. Nat. Mus., vol. 22, pp. 139- 

 142, 1900. 



Ball. W. H., U. S. Nat. Mus. Bull. 112, pi. 22, 1921. 



"Reed, R. D., The post-Monterey disturb.iuce in the Salinas Valley, Calif. Journ. 

 Geol., vol. 33, no. 6, pp. 591, G03, 606, 1925. 



