164 CALFFOUNIA ACADEMY OF SCIENCES. 



io8. Macoma nasuta Conrad var. kelseyi Ihill. 



Macoma kelsfyi Dai.i., Tiiuis. VVaj^ner lust. ScL, Vol. Ill, I'.irt 5, lyoo, p. 1052, PI. XI.IX, fig. 7. 



Shell of medium size, elongate-ovate, compressed, iliin; posterior extremity cuneiform, 

 obliquely truncated much above vciUimI niari^iii; umboiu's nc.irly central; ollur characteristics 

 same as in M. nasuta. 



Dimensions. — Long. 70 mm.; alt. 45 mm.; diani. i.S mm.; uml)o to aiUeiior end 31 mm.; to 

 posterior end 39 mm. 



r)i.stiii,u:iii.sli;il)le from other species liy same cliaracteri.stics that tli)stiii<;iiisli 

 M./i'istttn; (li.stiiigiii.shcd from .1/. n/iHutn by narrower, Ihitter shell, and more ol)li(|ue 

 tnincation of posterior end. Specimens identified by Dr. Dail. 



Rare in the upper San Pedro series at San Pedro and Los Cerritos. Found 

 also in the Pleistocene at Twenty-sixth Street, San Diego. 



Living. — San Diego and south (Dall). 



Pleistocene. — San Pedro; San Diego (Arnold). 



109. Macoma secta l.'onnnl. 



Platk XVI, Fig. 5. 



Tellina secta CoN., Jour. Phil. Acad. Sci., Vol. VII, 1.S37, p. 257. H.vni.ev, The.s. Coiirh., p. 337, 

 PI. LXV, figs. 245, 248, 1847. 



Macoma secta CoN., Carpenter, Brit. Assn. Repl., 1S63, [>. 639. H. & A. Adams, Gen. Rec. 

 Moll., p. 401, 1858. != Tellina ligametitina'DKSH . {fide Gabb, Pal. Cal., Vol. II, p. 73, 

 1869). Cooper, 7th Ann. Rcpt. Cal. .St. Min., 1888, p. 249. Keep, West Coast Shells, 

 p. 191, tig. 163, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 185. 



Macoma {Rexithezriis) secta CoN. ^ var. edulis (NuTT. mss.) Cpr. (fide Dall, Trans. Wagner Inst. 

 Sci., Vol. Ill, Part 5, 1900, p. 1053). 



Shell large, suboval, slightly ventricose, rather thin; uinbones subcentral, evenly rounded 

 anteriorly; posterior end truncated obliquely much above the base line; posterior dorsal margins 

 short, straight, sloping off quite steeply to angle where it meets line of truncation; fold prominent ; 

 surface sculptured bylines of growth; two cardinal teeth in each valve; ligament short, thick, in.serted 

 on an elongated, oblique, rib-like callus; margin beneath the gape appearing as if cut or broken; 

 pallial sinus large, expanded within, not reaching to anterior muscle-impression. 



Dimensions. — Long. <S2 mm.; alt. 65 mm.; diani. 24 mm. 



Distinguishable by large size, broad shell, subcentral nmbones, cciual convexity 

 of valves, and the prominent short ligamcntal callus. Resembles a Mactrn somewhat 

 ill outline. Specimens identified by Dr. Dull. 



Found in the lower San Pedro series at Deadman Island and San Pedro; and 

 in the upper San Pedro series at Deadman Island, Los Cerritos, Crawfish (Jeorge's, 

 San Pedro, and Long Heach. Found also in the Pleistocene at Spanish Uiglit, 

 San Diego. The specimen figured is from the upper San Pedro series at San Pedro, 

 and is now in the collection of Delos Arnold. 



Living. — Bodega Bay to San Diego; Japan (Cooper). 



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

 (Arnold). 



Pliocene. — Santa Barbara; San Fernando (Cooper). 



