1'20 CALIKOKNIA ACVDKMV OF SlUENCKS. 



(iuiius Modiolus Luinanh. 



Shell ol)lonjj, inlhitcd in liuiu; uiiiboncs anterior oblusc; liinj;u luotlilcbN; |)c(.lal impressions 

 three in each valve, the central elongated; epidermis often ])roduced into long beard-like fringes. 



'l\|n', Mijl'dus modiolus Liiitu'. . 



Seel ion .Vudiolus k. .s. 

 Surface smooth, shell inllated, edentulous, epidermis more or less hirsute. 

 'rv|ic, Mijtilus tnodio/us Litiiu''. 



42. Modiolus fornicatus ('(tr/ienUr. 



Modiola fornicata Cpk., Brit. Assn. Rep., 1863, p. 643; Ann. iS: Mag. Nat. Hist , 3rd Ser. .Vol. 

 XV, 1S65, p. 179. Keep, West Coast Shells, p. 173, 1892. Williamson, Proc. 

 U. S. Nat. Mus., Vol. XV, 1892, p. 191. 



Shell of medium size, short, oblong, inflated in front, swollen, equivalve; ijeaks anterior, 

 not quite terminal, obtuse, marginal, bent forward; surface sculptured oiilv with concentric incre- 

 mental lines; margins smooth; no hinge teeth. 



Dimemions. — Beaks to ventral margin 54 mm.; lat. 31 mm.; tiiam. 30 mm. 



This speciea is di«tiiii^iiislialtle by its short, swollen Inriu. 



Rare in the lower San Pcdi-o .series of Dcailmaii Island, and in the upper San 

 Tedro series of Los Cerritos. Foiinil also in the Pleistoeene of Barlow's ranch, 

 Ventura, and hluff west of bath-house, Santa Barbara. 



Liviny. — Monterey to Santa Bariiara (Carpenter): San Pedro (Williamson). 



Pleistocene. — San Pedro (Arnold): Ventura; Santa Barbara (Arnold). 



43. Modiolus rectus Conrad. 



A/odio/a recta CoN., Journ. Acad. Nat. Sci. Phil., Vol. VII, 1837, p. 243, pi. XIX, fig. i. Carpenter, 



Brit. Assn. Rept., 1863, p. 643. Gahh, Pal. Cal. Vol. II, p. loi, 1869. Cooper, 7th 



Ann. Rept. Cal. St. Min., 1888, p. 251. Keep, West Coa.st Shells, p. 171, fig. 145, 



1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192. Dall, Trans. 

 Wagner Inst. Sci., Vol. Ill, Part. 4, 1898, p. 793. 



Shell large, rhomboidal, narrow, evenly convex, not sharjily ridged, sculptured by numerous 

 fine, concentric, incremental lines; lower margin a nearly straight line; ligament long, narrow, 

 straight. 



Dimensions. — Long. 150 mm.; alt. 50 mm.; diam. 38 mm. 



Specimen identified by Dr. Dall. 



Rare in lower San Pedro scries of Deadmaii Island, and the iip[)er San Pedro 

 series of Deadman Island, San Pedro, and Los Cerritos. Found also in the Pliocene 

 of Pacific Beach, and the Pleistocene of Pacific Beach and Twenty-sixth Street, 

 San Diego. 



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



