21: 1053 Genus ‘Masao Leach, 1819. 7 
Shell oval or subrotund, convex, cardinal teeth narrow; no- 4 
lateral teeth; pallial impression with a ilochae: sf sinus, Pf 
21:1054 Macoma moesta Deshayes, 1854, a 
Arctic ocean; Bering sea; Circumboreal, | 4 
21:1055 Macoma balthica L, 
Widely distributed in Arctic regions, both Atlantic and Pa. 4 
cific. Shell small, thin, flat, white or pink, M. inconspicua B. | 
& S, is treated as a var. by Keep. In Cal, occurs as far south as 
Monterey, and specimens from the San Diego Pleistocene are r@- 
ferred here. ; 
21:1056 Macoma sitkana Dall, Sitka, Alaska. 
21:1067 Macoma kelseyi Dall, a var. of nasuta. J 
21:1058 ?Macoma pedroana Conr., is Tellina buttonl, @ 
21:1059 Macoma secta edulis Nutt., is typical secta, m. 
21:1060 Macoma tenera Leach, is calearea, 
21:1061 Macron kellettii Hinds, is aethiops (see Stearns, Phila, — 
Ac. Proc. i 
21:1062 Genus Mactra L., 1758, a 
Cardinal teeth moderate; lateral teeth elongated, linear, sub. 
equal; marginal ligament triangular, separated in pit by a testac- — 
eous Jamina; pallial sinus rounded. 
21:1063 Mactra planulata falcata Gid., is falcata. 
21:1064 Moera salmonea Cpr., is Tellina 8, 
21:1065 Mangilia (Cythara) branneri Arnold, 1903. 
San Pedro and Santa Barbara, Cal. (Pleistocene). 
21:1066 Mangilia (Clathurella) conradiana Gabb. San Pedro, Cal, _ 
21:1067 eeneiie hooveri Arnold, 1908. San Pedro, Cal, ((Pleia- — 
tocene “= 
21:1068 Mangilia interfossa pedroana Arnold. 
San Pedro and Santa Barbara, Cal, (Pleistocene), 
21:1069 Mangilia oldroydi Arnold, 1908. San Pedro, Cal, — 
(Pleistocene). : 
21:1070 Mangilia  painei Arnold, 1903. San Pedro, Cal. 
(Pleistocene). 3 
21:1071Mangilia sculpturata Dall. 
21:1072 Mangilia striosa C. B. Ad. San Pedro, Cal., to Panama. 
21:1073 Mangilia (Taranis) strongi Arnold, 1903. 
San Pedro, Sal. (Pleistocene, type). Alaska (G, Willett). 
21:1074 Margarita calostoma A. Ad., is pupilla, 
21:1075 Margarita cidaris A. Ad., is Solariella ce. 
21:1076 Margarita salmoneéa Cpr., is pupilla. 
21:1077 Margarites helicina Fabr. Arctic regions. : 
Shell about 6 mm in’ diam.; umbilicate, thin, flesh-color, pole — 
ished and shining. 
oun 
. vie 
21:1078 Marginella varia Sby., is californica. 
21:1079 Genus Malletia Desmoulins, 1832. 
Shell oval, compressed, smooth or concentrically furrowed, 
