240 



INDEX OF GENERA AND SPECIES. 



LEDA, 199. 



Leda protexta, 199. 



translucida, 199. 

 LIMA, Jur., 43; Cret., 202. 

 Lima appressa, 203. 

 ? cuneata, 44. 

 microtis, 202. 

 recticostata, 44. 

 ? sinuata, 43. 

 LIMOPSIS, 200. 



Limopsis transversa, 200. 



LlTHOPHAGUS, 185. 



Lithophagus oviformis, 185. 



LlTHOSTROTION, 5. 



Lithostrotion Californiense,6. 

 inamillare, 5. 



LlTTORINA, 131. 



Littorina compacta, 131. 

 LORIPES, 177. 



Loripes dubia, 177. 

 LUCINA, 175. 



Lucina cretacea, 177. 

 cumulata, 176. 

 nasuta, 175. 

 postradiata, 175. 

 subcircularis, 176. 

 LUNATIA, 105. 



Lunatia avellana, 105. 

 ? Conradiana, 107. 

 Hornii, 106. 

 nuciformis, 107. 

 Shumardiana, 106. 

 LUTRARIA, 154. 



Lutraria truncata, 154. 

 LYSIS, 138. 



Lysis duplicosta, 138. 



MACTRA, 153. 



Mactra Asburnerii 153. 



MARGARITELLA, 118. 



Margaritella crenulata, 118. 



globosa, 119. 

 MARTESIA, 145. 



Martesia clausa, 145. 

 MEEKIA, 191. 



Meekia navis, 192. 

 radiata, 192. 

 sella, 191. 

 MEGISTOSTOMA, 144. 



Megistostoma striata, 144. 

 MERETRIX, 163. 



Meretrix arata, 166. 



Californica, 166. 

 Hornii, 164. 

 lens, 164. 

 longa, 165. 

 nitida, 165. 

 ovalis, 166. 

 Uvasana, 163. 

 MITRA, 103. 



Mitra cretacea, 103. 

 MODIOLA, 184. 



Modiola cylindrica, 185. 

 ornata, 184. 

 Siskiyouensis, 184. 

 MONOTIS, 31. 



Monotis subcircularis, 31. 

 MORIO, 104. 



Morio tuberculatus, 104. 

 MYACITES, Trias., 28 ; Jur., 51. 

 Myacites depressus, 51. 



Humboldtensis, 28. 

 MYOPHORIA, 33. 



Myophoria alta, 33. 

 MYSIA. 178. 



Mysia polita, 178. 

 MYTILUS, Trias., 29; Jur., 49; Cret., 



183. 

 Mytilus ascia, 183. 



Homfrayi, 29. 

 humerus, 184. 

 multistriatus, 49. 

 pauperculus, 183. 



