ORTMANN I TERTIARY INVERTEBRATES. 



267 



39. Venus mcridionalis. 



40. Venus volckmanni. 



41. Venus patagonica (Phil., v. Ih.). 



42. Venus darwini. 



43. Venus navidadis. 



44. Dosinia meridionalis. 



45. Dosinia l&viuscula. 



46. Tellina tehuelcha (v. Ih.). 



47. Tellina jeguaensis. 



48. Tellina santacrusensis (v. Ih.). 



49. Psammobia patagonica. 



50. Mactra darwini. 



5 1 . Corbula hatcheri. 



52. Panopea regularis. 



53. Panopea quemadensis. 



54. Panopea nucleus (v. Ih.). 

 5 5 Martesia patagonica. 



56. Martesia pumila. 



57. Dentalium sulcosum. 



58. Liotia scotti. 



59. Leptothyra philippii. 



60. Solariella dautzenbergi. 



6 1 . Calliostoma peraratum. 



62. Calliostoma cossmanni. 



63. Calliostoma santacruzense. 



64. Calliostoma garretti. 



65. Calliostoma iheringi. 



66. Gibbula l&vis. 



67. Gibbula dalli. 



68. Gibbula diametralis. 



69. Odontostomia suturalis. 



70. Scalaria rugulosa. 



71. Infundibulum corrugatum. 



72. Infundibulum clypeolum. 



73. Sigapatella americana. 



74. Crepidida gregaria. 



75. Natica ovoidea. 



76. Natica secunda. 



77. Natica darwini. 



78. Natica subtenuis. 



79. Natica consimilis. 



80. Turritella ambulacrum. 



8 1 . Turritella breantiana. 



82. Turritella patagonica. 



83. Aporrhais araucana. 



84. Struthiolaria ameghinoi. 



85. Struthiolaria ornata. 



86. Dolium ovulum. 



87. Pyrola Carolina. 



88. Tritonium bicegoi. 



89. Tritonium morgani. 



90. Buccimim anna. 



91. Buccinum obesum. 



92. Chrysodomus cancellatus. 

 9 3 . Chrysodomus pilsbryi. 



94. Siplwnalia domeykoana. 



95. Trophon patagonicus. 



96. Urosalpinx elegans. 



97. Urosalpinx cossmanni. 



98. /* torosus. 



99. Marginella gracilior. 



100. Marginella plicifera. 



101. Marginella olivella. 



1 02. Valuta triplicata. 



103. Valuta gracilior. 



104. Valuta petersoni. 



105. Valuta dorbignyana. 



1 06. Valuta domeykoana. 



107. Cancellaria gracilis. 



1 08. Cancellaria cf. medince. 



109. Cancellaria -vidali (Phil.). 



1 10. Terebra costellata. 

 in. Pleurotoma subcequalis, 



112. Pleurotoma unifayialis. 



113. Genota cuevensis. 



1 1 4. Drillia santacnizensis. 



115. Borsonia patagonica. 



1 1 6. Bulla patagonica. 



1 1 7. Geryon peruvianus. 



The question arises, which one of Ameghino's subdivisions is repre- 

 sented in this fauna. According to Mr. Hatcher, this fauna is a unit 

 stratigraphically, and no subdivisions are possible; he tried at first, in 

 collecting, to distinguish different horizons, but soon found that this was 



