I'.KS C'ALIKOKNIA A(;AU1;MV Of SCIENCES. 



lAiHHCj. — Lower California (Carpenter): West Coast (Keep) : Halfniooii Ray 

 (Arnold). 



Pleistocene. — San Pedro (Arnold): San Nicolas Island (Bowers. 



Siipcronlcr STRl' PTONKUR A. 



Order CTENOBRANCHIATA. 



Supcrfamily TOXOGLOSSA. 



Family L. TEREBRID.-E. 



Genus Terebra Bruguiere. 



Shell elongated, turriculated, narrow, solid; wliorls numerous, rather flattened, with super- 

 ficially impressed sutures; aperture small, ovate, profoundly notched at base; columella oblique. 



Terebra nebulosa Sowerby is a characteristic specie|. 



Section Acus (Huviphrey) Gray. 



i6i. Terebra (Acus) simplex Carpenter. 



Myurella simplex Cpr., Brit. Assn. Rept., 1863, p. 657; Ann. & Mag. Nat. Hist., 3rd Ser., 

 Vol. XV, 1865, p. 395. Gabb, Pal. Cal, Vol. II, p. 78, 1869. Cooper, 7th Ann. 

 Rept. Cal. St. Min., 1888, p. 253. Keep, West Coast Shells, p. 56, fig, 40, 1892. 



Terebra simplex Cpr., ^T. variegala Gray i^fide Tryon, Man. Conch., Vol. VII, p. 14, 1885). 



Terebra (Acus) simplex Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 207. 



Shell small, turreted, slender; ape.x acute; whorls ten to eleven, flat; sculpture consists of 

 about fourteen faint, transverse ribs, each terminated on anterior end by a prominent node; a pseudo 

 suture separates the row of nodes from the main part of the whorl; incremental lines visible; suture 

 impressed, distinct; aperture subelliptical; outer lip thin, slightly arcuate anteriorly; inner lip smooth; 

 plication on columella; sinus short. 



Dimensions. — Long. 33 mm.; lat. 9 mm.; body-whorl 13 mm.; aperture 9 mm.; defl. 

 18 degrees. 



Sculpture in thi.s species is quite variable; some specimens have the row of 

 nodes prominently elevated, others show only a little constriction at upper third of 

 transverse ridge. 



Common in upper, rare in lower San Pedro series of the San Pedro region. 

 Rare in the Pliocene of Deadman Island and Timm's Point. Found in the Pleis- 

 tocene at Barlow's ranch, Ventura, and at Twenty-sixth Street, Spanish Bight, and 

 Pacific Beach, San Diego. 



Living. — Santa Barbara to San Diego (Cooper). 



Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; San Diego; 

 Ventura (Arnold). 



Pliocene. — San Diego well (Dall): San Pedro (Arnold). 



